| Message ID | 20210625132544.18094-1-nchatrad@amd.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [1/3] hwmon: sbrmi: Add support for sbrmi power module | expand |
On 6/25/21 6:25 AM, Naveen Krishna Chatradhi wrote: > From: Akshay Gupta <Akshay.Gupta@amd.com> > > On AMD platforms the Out-of-band access is provided by Advanced Platform Management This is a bit too long for checkpatch. > Link (APML), APML is a SMBus v2.0 compatible 2-wire processor client interface. > APML is also referred as the sideband interface (SBI). > > APML is used to communicate with the Remote Management Interface > (SB-Remote Management Interface (SB-RMI) which provides Soft Mailbox messages > to report power consumption and power limits of the CPU socket. > > - This module add support to read power consumption, > power limit & max power limit and write power limit. > - To instantiate this driver on an AMD CPU with SB-RMI support, > the i2c bus number would be the bus connected from the board > management controller (BMC) to the CPU. > This is a bit vague. Would this driver be instantiated on the host CPU or on the BMC ? > Signed-off-by: Akshay Gupta <Akshay.Gupta@amd.com> > Signed-off-by: Naveen Krishna Chatradhi <nchatrad@amd.com> > --- > drivers/hwmon/Kconfig | 10 ++ > drivers/hwmon/Makefile | 1 + > drivers/hwmon/sbrmi.c | 394 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 405 insertions(+) > create mode 100644 drivers/hwmon/sbrmi.c > > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > index 87624902ea80..d1813ea8382c 100644 > --- a/drivers/hwmon/Kconfig > +++ b/drivers/hwmon/Kconfig > @@ -1551,6 +1551,16 @@ config SENSORS_SBTSI > This driver can also be built as a module. If so, the module will > be called sbtsi_temp. > > +config SENSORS_SBRMI > + tristate "Emulated SB-RMI sensor" > + depends on I2C > + help > + If you say yes here you get support for emulated RMI > + sensors on AMD SoCs with APML interface connected to a BMC device. > + > + This driver can also be built as a module. If so, the module will > + be called sbrmi. > + > config SENSORS_SHT15 > tristate "Sensiron humidity and temperature sensors. SHT15 and compat." > depends on GPIOLIB || COMPILE_TEST > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > index 59e78bc212cf..8031acf58936 100644 > --- a/drivers/hwmon/Makefile > +++ b/drivers/hwmon/Makefile > @@ -164,6 +164,7 @@ obj-$(CONFIG_SENSORS_PWM_FAN) += pwm-fan.o > obj-$(CONFIG_SENSORS_RASPBERRYPI_HWMON) += raspberrypi-hwmon.o > obj-$(CONFIG_SENSORS_S3C) += s3c-hwmon.o > obj-$(CONFIG_SENSORS_SBTSI) += sbtsi_temp.o > +obj-$(CONFIG_SENSORS_SBRMI) += sbrmi.o > obj-$(CONFIG_SENSORS_SCH56XX_COMMON)+= sch56xx-common.o > obj-$(CONFIG_SENSORS_SCH5627) += sch5627.o > obj-$(CONFIG_SENSORS_SCH5636) += sch5636.o > diff --git a/drivers/hwmon/sbrmi.c b/drivers/hwmon/sbrmi.c > new file mode 100644 > index 000000000000..c35829513459 > --- /dev/null > +++ b/drivers/hwmon/sbrmi.c > @@ -0,0 +1,394 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * sbrmi.c - hwmon driver for a SB-RMI mailbox > + * compliant AMD SoC device. > + * > + * Copyright (C) 2020-2021 Advanced Micro Devices, Inc. > + */ > + > +#include <linux/err.h> > +#include <linux/hwmon.h> > +#include <linux/i2c.h> > +#include <linux/init.h> > +#include <linux/module.h> > +#include <linux/mutex.h> > +#include <linux/of.h> > +#include <linux/of_device.h> I don't immediately see why this include is needed. > +#include <asm-generic/ioctl.h> This looks wrong, and I don't immediately see why it would be needed. > +#include <linux/delay.h> Alphabetic include file order, please. > + > +/* Do not allow setting negative power limit */ > +#define SBRMI_PWR_MIN 0 > +/* Mask for Status Register bit[1] */ > +#define SW_ALERT_MASK 0x2 > + Please always use #define<space>DEFINITION<tab>value ^^^^^ > +/* Software Interrupt for triggering */ > +#define START_CMD 0x80 > +#define TRIGGER_MAILBOX 0x01 > + > +/* > + * SB-RMI supports soft mailbox service request to MP1 (power management > + * firmware) through SBRMI inbound/outbound message registers. > + * SB-RMI message IDs > + */ > +enum sbrmi_msg_id { > + SBRMI_READ_PKG_PWR_CONSUMPTION = 0x1, > + SBRMI_WRITE_PKG_PWR_LIMIT, > + SBRMI_READ_PKG_PWR_LIMIT, > + SBRMI_READ_PKG_MAX_PWR_LIMIT, > +}; > + > +/* SB-RMI registers */ > +enum sbrmi_reg { > + SBRMI_CTRL = 0x01, > + SBRMI_STATUS, > + SBRMI_OUTBNDMSG0 = 0x30, > + SBRMI_OUTBNDMSG1, > + SBRMI_OUTBNDMSG2, > + SBRMI_OUTBNDMSG3, > + SBRMI_OUTBNDMSG4, > + SBRMI_OUTBNDMSG5, > + SBRMI_OUTBNDMSG6, > + SBRMI_OUTBNDMSG7, > + SBRMI_INBNDMSG0, > + SBRMI_INBNDMSG1, > + SBRMI_INBNDMSG2, > + SBRMI_INBNDMSG3, > + SBRMI_INBNDMSG4, > + SBRMI_INBNDMSG5, > + SBRMI_INBNDMSG6, > + SBRMI_INBNDMSG7, > + SBRMI_SW_INTERRUPT, > +}; > + > +/* > + * Each client has this additional data > + */ Please be consistent with comments: This does not really need to be a multi-line comment. While that does not really matter, you use a single-line comment to describe the next structure. Please make it both either single-line or multi-line. > +struct sbrmi_data { > + struct i2c_client *client; > + struct mutex lock; > +}; > + > +/* Mailbox message data format */ > +union mailbox_word { > + u8 bytes[4]; > + u32 value; That strongly suggests that the driver will only work on either little-endian or big-endian systems, depending on the byte order of transfers. Please restrict it accordingly. > +}; > + > +struct sbrmi_mailbox_msg { > + u8 cmd; > + bool read; > + union mailbox_word data_in; > + union mailbox_word data_out; > +}; > + > +static int print_mailbox_error(struct sbrmi_data *data) > +{ Nit> Many functions only use data>client and, in some cases, dereference it several times. It might be easier to just pass 'client'. > + int status; > + > + /* Mailbox error code will be written by Firmware in > + * SBRMI::OutBndMsg_inst7 (SBRMI_x37) > + */ /* * Please use standard multi-line comments. Applies to entire driver. */ > + status = i2c_smbus_read_byte_data(data->client, SBRMI_OUTBNDMSG7); > + if (status < 0) { > + pr_err("SMBUS translation failed\n"); > + return status; > + } > + > + switch (status) { > + case 0x0: /* Success */ > + break; > + case 0x1: > + pr_err("Mailbox message command is aborted\n"); > + break; > + case 0x2: > + pr_err("Unknown mailbox message\n"); > + break; > + case 0x3: > + pr_err("Invalid core is specified in mailbox message parameters\n"); > + break; > + default: > + pr_err("Unknown Error\n"); > + } Is this noise necessary ? I am concerned that, if it occurs, it would be persistent and fill up the kernel log with noise. > + > + return status; Error codes are supposed to be negative and standard Linux error codes. Please convert the above errors to standard Linux error codes. > +} > + > +static int sbrmi_enable_alert(struct sbrmi_data *data) > +{ > + int ctrl; > + > + /* Enable the SB-RMI Software alert status > + * by writing 0 to bit 4 of Control register(0x1) > + */ > + ctrl = i2c_smbus_read_byte_data(data->client, SBRMI_CTRL); > + if (ctrl < 0) > + return ctrl; > + > + if (ctrl & 0x10) { > + ctrl &= ~0x10; > + return i2c_smbus_write_byte_data(data->client, > + SBRMI_CTRL, ctrl); > + } > + > + return 0; > +} > + > +static int rmi_mailbox_xfer(struct sbrmi_data *data, > + struct sbrmi_mailbox_msg *msg) > +{ > + union mailbox_word output, input; > + int i, err = 0, retry = 10; Initializing 'err' is unnecessary. > + int sw_status; > + > + mutex_lock(&data->lock); > + > + err = sbrmi_enable_alert(data); > + if (err < 0) > + goto exit_unlock; > + > + /* Indicate firmware a command is to be serviced */ > + err = i2c_smbus_write_byte_data(data->client, > + SBRMI_INBNDMSG7, START_CMD); > + if (err < 0) > + goto exit_unlock; > + > + /* Write the command to SBRMI::InBndMsg_inst0 */ > + err = i2c_smbus_write_byte_data(data->client, > + SBRMI_INBNDMSG0, msg->cmd); > + if (err < 0) > + goto exit_mod; > + > + /* > + * For both read and write the initiator (BMC) writes > + * Command Data In[31:0] to SBRMI::InBndMsg_inst[4:1] > + * SBRMI_x3C(MSB):SBRMI_x39(LSB) > + */ > + input = msg->data_in; > + for (i = 0; i < 3; i++) { This writes 3 bytes. Is that on purpose ? If so please explain since the above suggests that 4 bytes should be written. > + err = i2c_smbus_write_byte_data(data->client, > + (SBRMI_INBNDMSG1 + i), Unnecessary ( ) > + input.bytes[i]); > + if (err < 0) > + goto exit_mod; > + } > + > + /* > + * Write 0x01 to SBRMI::SoftwareInterrupt to notify firmware to > + * perform the requested read or write command > + */ > + err = i2c_smbus_write_byte_data(data->client, > + SBRMI_SW_INTERRUPT, TRIGGER_MAILBOX); > + if (err < 0) > + goto exit_mod; > + > + /* > + * Firmware will write SBRMI::Status[SwAlertSts]=1 to generate > + * an ALERT (if enabled) to initiator (BMC) to indicate completion > + * of the requested command > + */ > + do { > + sw_status = i2c_smbus_read_byte_data(data->client, > + SBRMI_STATUS); > + if (sw_status < 0) { > + err = sw_status; > + goto exit_mod; > + } > + if (sw_status & SW_ALERT_MASK) > + break; > + usleep_range(50, 100); > + } while (retry--); > + > + if (retry < 0) { > + pr_err("Firmware fail to indicate command colmpletion\n"); completion > + err = -1; > + goto exit_mod; > + } > + > + /* > + * For a read operation, the initiator (BMC) reads the firmware response > + * Command Data Out[31:0] from SBRMI::OutBndMsg_inst[4:1] > + * {SBRMI_x34(MSB):SBRMI_x31(LSB)}. > + */ > + if (msg->read) { > + for (i = 0; i < 4; i++) { > + output.bytes[i] = i2c_smbus_read_byte_data(data->client, > + (SBRMI_OUTBNDMSG1 + i)); Unnecessary (). > + if (output.bytes[i] < 0) { output.bytes is defined as u8. This will not catch errors. > + err = output.bytes[i]; > + goto exit_mod; > + } > + } > + } > + msg->data_out = output; > + > + /* > + * BMC must write 1'b1 to SBRMI::Status[SwAlertSts] to clear the > + * ALERT to initiator > + */ > + err = i2c_smbus_write_byte_data(data->client, SBRMI_STATUS, > + (sw_status | SW_ALERT_MASK)); Unnecessary (). > + > +exit_mod: > + if (err < 0) > + pr_err("SMBUS translation failed\n"); > + else > + err = print_mailbox_error(data); > +exit_unlock: > + mutex_unlock(&data->lock); > + return err; > +} > + > +static int sbrmi_read(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long *val) > +{ > + struct sbrmi_data *data = dev_get_drvdata(dev); > + struct sbrmi_mailbox_msg msg = { 0 }; > + int ret; > + > + if (type != hwmon_power) > + return -EINVAL; > + > + msg.read = true; > + switch (attr) { > + case hwmon_power_input: > + msg.cmd = SBRMI_READ_PKG_PWR_CONSUMPTION; > + ret = rmi_mailbox_xfer(data, &msg); > + break; > + case hwmon_power_cap: > + msg.cmd = SBRMI_READ_PKG_PWR_LIMIT; > + ret = rmi_mailbox_xfer(data, &msg); > + break; > + case hwmon_power_cap_max: > + msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; > + ret = rmi_mailbox_xfer(data, &msg); > + break; > + default: > + return -EINVAL; > + } > + /* > + * hwmon power attributes are in microWatt > + */ > + *val = (long)msg.data_out.value * 1000; > + return ret; > +} > + > +static int sbrmi_write(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long val) > +{ > + struct sbrmi_data *data = dev_get_drvdata(dev); > + struct sbrmi_mailbox_msg msg = { 0 }; > + > + if (type != hwmon_power && attr != hwmon_power_cap) > + return -EINVAL; > + /* > + * hwmon power attributes are in microWatt > + * mailbox read/write is in mWatt > + */ > + val /= 1000; > + > + msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; > + msg.data_in.value = 0; > + msg.read = true; > + rmi_mailbox_xfer(data, &msg); > + > + val = clamp_val(val, SBRMI_PWR_MIN, msg.data_out.value); > + > + msg.cmd = SBRMI_WRITE_PKG_PWR_LIMIT; > + msg.data_in.value = val; > + msg.read = false; > + > + return rmi_mailbox_xfer(data, &msg); > +} > + > +static umode_t sbrmi_is_visible(const void *data, > + enum hwmon_sensor_types type, > + u32 attr, int channel) > +{ > + switch (type) { > + case hwmon_power: > + switch (attr) { > + case hwmon_power_input: > + case hwmon_power_cap_max: > + return 0444; > + case hwmon_power_cap: > + return 0644; > + } > + break; > + default: > + break; > + } > + return 0; > +} > + > +static const struct hwmon_channel_info *sbrmi_info[] = { > + HWMON_CHANNEL_INFO(power, > + HWMON_P_INPUT | HWMON_P_CAP | HWMON_P_CAP_MAX), > + NULL > +}; > + > +static const struct hwmon_ops sbrmi_hwmon_ops = { > + .is_visible = sbrmi_is_visible, > + .read = sbrmi_read, > + .write = sbrmi_write, > +}; > + > +static const struct hwmon_chip_info sbrmi_chip_info = { > + .ops = &sbrmi_hwmon_ops, > + .info = sbrmi_info, > +}; > + > +static int sbrmi_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct device *dev = &client->dev; > + struct device *hwmon_dev; > + struct sbrmi_data *data; > + > + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { > + dev_err(&client->dev, "adapter does not support true I2C\n"); Why would that matter? It only uses SMBus functions. > + return -ENODEV; > + } > + > + data = devm_kzalloc(dev, sizeof(struct sbrmi_data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->client = client; > + mutex_init(&data->lock); > + > + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data, > + &sbrmi_chip_info, NULL); > + > + return PTR_ERR_OR_ZERO(hwmon_dev); > +} > + > +static const struct i2c_device_id sbrmi_id[] = { > + {"sbrmi", 0}, > + {} > +}; > +MODULE_DEVICE_TABLE(i2c, sbrmi_id); > + > +static const struct of_device_id __maybe_unused sbrmi_of_match[] = { > + { > + .compatible = "amd,sbrmi", > + }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, sbrmi_of_match); > + > +static struct i2c_driver sbrmi_driver = { > + .class = I2C_CLASS_HWMON, > + .driver = { > + .name = "sbrmi", > + .of_match_table = of_match_ptr(sbrmi_of_match), > + }, > + .probe = sbrmi_probe, > + .id_table = sbrmi_id, > +}; > + > +module_i2c_driver(sbrmi_driver); > + > +MODULE_AUTHOR("Akshay Gupta <akshay.gupta@amd.com>"); > +MODULE_DESCRIPTION("Hwmon driver for AMD SB-RMI emulated sensor"); > +MODULE_LICENSE("GPL"); >
[AMD Official Use Only] Hi Guenter, -----Original Message----- From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck Sent: Monday, June 28, 2021 8:29 PM To: Chatradhi, Naveen Krishna <NaveenKrishna.Chatradhi@amd.com>; linux-hwmon@vger.kernel.org Cc: Gupta, Akshay <Akshay.Gupta@amd.com> Subject: Re: [PATCH 1/3] hwmon: sbrmi: Add support for sbrmi power module [CAUTION: External Email] On 6/25/21 6:25 AM, Naveen Krishna Chatradhi wrote: > From: Akshay Gupta <Akshay.Gupta@amd.com> > > On AMD platforms the Out-of-band access is provided by Advanced > Platform Management This is a bit too long for checkpatch. > Link (APML), APML is a SMBus v2.0 compatible 2-wire processor client interface. > APML is also referred as the sideband interface (SBI). > > APML is used to communicate with the Remote Management Interface > (SB-Remote Management Interface (SB-RMI) which provides Soft Mailbox > messages to report power consumption and power limits of the CPU socket. > > - This module add support to read power consumption, > power limit & max power limit and write power limit. > - To instantiate this driver on an AMD CPU with SB-RMI support, > the i2c bus number would be the bus connected from the board > management controller (BMC) to the CPU. > This is a bit vague. Would this driver be instantiated on the host CPU or on the BMC ? > Signed-off-by: Akshay Gupta <Akshay.Gupta@amd.com> > Signed-off-by: Naveen Krishna Chatradhi <nchatrad@amd.com> > --- > drivers/hwmon/Kconfig | 10 ++ > drivers/hwmon/Makefile | 1 + > drivers/hwmon/sbrmi.c | 394 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 405 insertions(+) > create mode 100644 drivers/hwmon/sbrmi.c > > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index > 87624902ea80..d1813ea8382c 100644 > --- a/drivers/hwmon/Kconfig > +++ b/drivers/hwmon/Kconfig > @@ -1551,6 +1551,16 @@ config SENSORS_SBTSI > This driver can also be built as a module. If so, the module will > be called sbtsi_temp. > > +config SENSORS_SBRMI > + tristate "Emulated SB-RMI sensor" > + depends on I2C > + help > + If you say yes here you get support for emulated RMI > + sensors on AMD SoCs with APML interface connected to a BMC device. > + > + This driver can also be built as a module. If so, the module will > + be called sbrmi. > + > config SENSORS_SHT15 > tristate "Sensiron humidity and temperature sensors. SHT15 and compat." > depends on GPIOLIB || COMPILE_TEST diff --git > a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index > 59e78bc212cf..8031acf58936 100644 > --- a/drivers/hwmon/Makefile > +++ b/drivers/hwmon/Makefile > @@ -164,6 +164,7 @@ obj-$(CONFIG_SENSORS_PWM_FAN) += pwm-fan.o > obj-$(CONFIG_SENSORS_RASPBERRYPI_HWMON) += raspberrypi-hwmon.o > obj-$(CONFIG_SENSORS_S3C) += s3c-hwmon.o > obj-$(CONFIG_SENSORS_SBTSI) += sbtsi_temp.o > +obj-$(CONFIG_SENSORS_SBRMI) += sbrmi.o > obj-$(CONFIG_SENSORS_SCH56XX_COMMON)+= sch56xx-common.o > obj-$(CONFIG_SENSORS_SCH5627) += sch5627.o > obj-$(CONFIG_SENSORS_SCH5636) += sch5636.o > diff --git a/drivers/hwmon/sbrmi.c b/drivers/hwmon/sbrmi.c new file > mode 100644 index 000000000000..c35829513459 > --- /dev/null > +++ b/drivers/hwmon/sbrmi.c > @@ -0,0 +1,394 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * sbrmi.c - hwmon driver for a SB-RMI mailbox > + * compliant AMD SoC device. > + * > + * Copyright (C) 2020-2021 Advanced Micro Devices, Inc. > + */ > + > +#include <linux/err.h> > +#include <linux/hwmon.h> > +#include <linux/i2c.h> > +#include <linux/init.h> > +#include <linux/module.h> > +#include <linux/mutex.h> > +#include <linux/of.h> > +#include <linux/of_device.h> I don't immediately see why this include is needed. > +#include <asm-generic/ioctl.h> This looks wrong, and I don't immediately see why it would be needed. > +#include <linux/delay.h> Alphabetic include file order, please. > + > +/* Do not allow setting negative power limit */ #define SBRMI_PWR_MIN > +0 > +/* Mask for Status Register bit[1] */ #define SW_ALERT_MASK 0x2 > + Please always use #define<space>DEFINITION<tab>value ^^^^^ > +/* Software Interrupt for triggering */ > +#define START_CMD 0x80 > +#define TRIGGER_MAILBOX 0x01 > + > +/* > + * SB-RMI supports soft mailbox service request to MP1 (power > +management > + * firmware) through SBRMI inbound/outbound message registers. > + * SB-RMI message IDs > + */ > +enum sbrmi_msg_id { > + SBRMI_READ_PKG_PWR_CONSUMPTION = 0x1, > + SBRMI_WRITE_PKG_PWR_LIMIT, > + SBRMI_READ_PKG_PWR_LIMIT, > + SBRMI_READ_PKG_MAX_PWR_LIMIT, > +}; > + > +/* SB-RMI registers */ > +enum sbrmi_reg { > + SBRMI_CTRL = 0x01, > + SBRMI_STATUS, > + SBRMI_OUTBNDMSG0 = 0x30, > + SBRMI_OUTBNDMSG1, > + SBRMI_OUTBNDMSG2, > + SBRMI_OUTBNDMSG3, > + SBRMI_OUTBNDMSG4, > + SBRMI_OUTBNDMSG5, > + SBRMI_OUTBNDMSG6, > + SBRMI_OUTBNDMSG7, > + SBRMI_INBNDMSG0, > + SBRMI_INBNDMSG1, > + SBRMI_INBNDMSG2, > + SBRMI_INBNDMSG3, > + SBRMI_INBNDMSG4, > + SBRMI_INBNDMSG5, > + SBRMI_INBNDMSG6, > + SBRMI_INBNDMSG7, > + SBRMI_SW_INTERRUPT, > +}; > + > +/* > + * Each client has this additional data */ Please be consistent with comments: This does not really need to be a multi-line comment. While that does not really matter, you use a single-line comment to describe the next structure. Please make it both either single-line or multi-line. > +struct sbrmi_data { > + struct i2c_client *client; > + struct mutex lock; > +}; > + > +/* Mailbox message data format */ > +union mailbox_word { > + u8 bytes[4]; > + u32 value; That strongly suggests that the driver will only work on either little-endian or big-endian systems, depending on the byte order of transfers. Please restrict it accordingly. > +}; > + > +struct sbrmi_mailbox_msg { > + u8 cmd; > + bool read; > + union mailbox_word data_in; > + union mailbox_word data_out; > +}; > + > +static int print_mailbox_error(struct sbrmi_data *data) { Nit> Many functions only use data>client and, in some cases, dereference Nit> it several times. It might be easier to just pass 'client'. > + int status; > + > + /* Mailbox error code will be written by Firmware in > + * SBRMI::OutBndMsg_inst7 (SBRMI_x37) > + */ /* * Please use standard multi-line comments. Applies to entire driver. */ > + status = i2c_smbus_read_byte_data(data->client, SBRMI_OUTBNDMSG7); > + if (status < 0) { > + pr_err("SMBUS translation failed\n"); > + return status; > + } > + > + switch (status) { > + case 0x0: /* Success */ > + break; > + case 0x1: > + pr_err("Mailbox message command is aborted\n"); > + break; > + case 0x2: > + pr_err("Unknown mailbox message\n"); > + break; > + case 0x3: > + pr_err("Invalid core is specified in mailbox message parameters\n"); > + break; > + default: > + pr_err("Unknown Error\n"); > + } Is this noise necessary ? I am concerned that, if it occurs, it would be persistent and fill up the kernel log with noise. > + > + return status; Error codes are supposed to be negative and standard Linux error codes. Please convert the above errors to standard Linux error codes. > +} > + > +static int sbrmi_enable_alert(struct sbrmi_data *data) { > + int ctrl; > + > + /* Enable the SB-RMI Software alert status > + * by writing 0 to bit 4 of Control register(0x1) > + */ > + ctrl = i2c_smbus_read_byte_data(data->client, SBRMI_CTRL); > + if (ctrl < 0) > + return ctrl; > + > + if (ctrl & 0x10) { > + ctrl &= ~0x10; > + return i2c_smbus_write_byte_data(data->client, > + SBRMI_CTRL, ctrl); > + } > + > + return 0; > +} > + > +static int rmi_mailbox_xfer(struct sbrmi_data *data, > + struct sbrmi_mailbox_msg *msg) { > + union mailbox_word output, input; > + int i, err = 0, retry = 10; Initializing 'err' is unnecessary. > + int sw_status; > + > + mutex_lock(&data->lock); > + > + err = sbrmi_enable_alert(data); > + if (err < 0) > + goto exit_unlock; > + > + /* Indicate firmware a command is to be serviced */ > + err = i2c_smbus_write_byte_data(data->client, > + SBRMI_INBNDMSG7, START_CMD); > + if (err < 0) > + goto exit_unlock; > + > + /* Write the command to SBRMI::InBndMsg_inst0 */ > + err = i2c_smbus_write_byte_data(data->client, > + SBRMI_INBNDMSG0, msg->cmd); > + if (err < 0) > + goto exit_mod; > + > + /* > + * For both read and write the initiator (BMC) writes > + * Command Data In[31:0] to SBRMI::InBndMsg_inst[4:1] > + * SBRMI_x3C(MSB):SBRMI_x39(LSB) > + */ > + input = msg->data_in; > + for (i = 0; i < 3; i++) { This writes 3 bytes. Is that on purpose ? If so please explain since the above suggests that 4 bytes should be written. > + err = i2c_smbus_write_byte_data(data->client, > + (SBRMI_INBNDMSG1 + i), Unnecessary ( ) > + input.bytes[i]); > + if (err < 0) > + goto exit_mod; > + } > + > + /* > + * Write 0x01 to SBRMI::SoftwareInterrupt to notify firmware to > + * perform the requested read or write command > + */ > + err = i2c_smbus_write_byte_data(data->client, > + SBRMI_SW_INTERRUPT, TRIGGER_MAILBOX); > + if (err < 0) > + goto exit_mod; > + > + /* > + * Firmware will write SBRMI::Status[SwAlertSts]=1 to generate > + * an ALERT (if enabled) to initiator (BMC) to indicate completion > + * of the requested command > + */ > + do { > + sw_status = i2c_smbus_read_byte_data(data->client, > + SBRMI_STATUS); > + if (sw_status < 0) { > + err = sw_status; > + goto exit_mod; > + } > + if (sw_status & SW_ALERT_MASK) > + break; > + usleep_range(50, 100); > + } while (retry--); > + > + if (retry < 0) { > + pr_err("Firmware fail to indicate command > + colmpletion\n"); completion > + err = -1; > + goto exit_mod; > + } > + > + /* > + * For a read operation, the initiator (BMC) reads the firmware response > + * Command Data Out[31:0] from SBRMI::OutBndMsg_inst[4:1] > + * {SBRMI_x34(MSB):SBRMI_x31(LSB)}. > + */ > + if (msg->read) { > + for (i = 0; i < 4; i++) { > + output.bytes[i] = i2c_smbus_read_byte_data(data->client, > + > + (SBRMI_OUTBNDMSG1 + i)); Unnecessary (). > + if (output.bytes[i] < 0) { output.bytes is defined as u8. This will not catch errors. > + err = output.bytes[i]; > + goto exit_mod; > + } > + } > + } > + msg->data_out = output; > + > + /* > + * BMC must write 1'b1 to SBRMI::Status[SwAlertSts] to clear the > + * ALERT to initiator > + */ > + err = i2c_smbus_write_byte_data(data->client, SBRMI_STATUS, > + (sw_status | SW_ALERT_MASK)); Unnecessary (). > + > +exit_mod: > + if (err < 0) > + pr_err("SMBUS translation failed\n"); > + else > + err = print_mailbox_error(data); > +exit_unlock: > + mutex_unlock(&data->lock); > + return err; > +} > + > +static int sbrmi_read(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long *val) { > + struct sbrmi_data *data = dev_get_drvdata(dev); > + struct sbrmi_mailbox_msg msg = { 0 }; > + int ret; > + > + if (type != hwmon_power) > + return -EINVAL; > + > + msg.read = true; > + switch (attr) { > + case hwmon_power_input: > + msg.cmd = SBRMI_READ_PKG_PWR_CONSUMPTION; > + ret = rmi_mailbox_xfer(data, &msg); > + break; > + case hwmon_power_cap: > + msg.cmd = SBRMI_READ_PKG_PWR_LIMIT; > + ret = rmi_mailbox_xfer(data, &msg); > + break; > + case hwmon_power_cap_max: > + msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; > + ret = rmi_mailbox_xfer(data, &msg); > + break; > + default: > + return -EINVAL; > + } > + /* > + * hwmon power attributes are in microWatt > + */ > + *val = (long)msg.data_out.value * 1000; > + return ret; > +} > + > +static int sbrmi_write(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long val) { > + struct sbrmi_data *data = dev_get_drvdata(dev); > + struct sbrmi_mailbox_msg msg = { 0 }; > + > + if (type != hwmon_power && attr != hwmon_power_cap) > + return -EINVAL; > + /* > + * hwmon power attributes are in microWatt > + * mailbox read/write is in mWatt > + */ > + val /= 1000; > + > + msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; > + msg.data_in.value = 0; > + msg.read = true; > + rmi_mailbox_xfer(data, &msg); > + > + val = clamp_val(val, SBRMI_PWR_MIN, msg.data_out.value); > + > + msg.cmd = SBRMI_WRITE_PKG_PWR_LIMIT; > + msg.data_in.value = val; > + msg.read = false; > + > + return rmi_mailbox_xfer(data, &msg); } > + > +static umode_t sbrmi_is_visible(const void *data, > + enum hwmon_sensor_types type, > + u32 attr, int channel) { > + switch (type) { > + case hwmon_power: > + switch (attr) { > + case hwmon_power_input: > + case hwmon_power_cap_max: > + return 0444; > + case hwmon_power_cap: > + return 0644; > + } > + break; > + default: > + break; > + } > + return 0; > +} > + > +static const struct hwmon_channel_info *sbrmi_info[] = { > + HWMON_CHANNEL_INFO(power, > + HWMON_P_INPUT | HWMON_P_CAP | HWMON_P_CAP_MAX), > + NULL > +}; > + > +static const struct hwmon_ops sbrmi_hwmon_ops = { > + .is_visible = sbrmi_is_visible, > + .read = sbrmi_read, > + .write = sbrmi_write, > +}; > + > +static const struct hwmon_chip_info sbrmi_chip_info = { > + .ops = &sbrmi_hwmon_ops, > + .info = sbrmi_info, > +}; > + > +static int sbrmi_probe(struct i2c_client *client, > + const struct i2c_device_id *id) { > + struct device *dev = &client->dev; > + struct device *hwmon_dev; > + struct sbrmi_data *data; > + > + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { > + dev_err(&client->dev, "adapter does not support true > + I2C\n"); Why would that matter? It only uses SMBus functions. > + return -ENODEV; > + } > + > + data = devm_kzalloc(dev, sizeof(struct sbrmi_data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->client = client; > + mutex_init(&data->lock); > + > + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data, > + > + &sbrmi_chip_info, NULL); > + > + return PTR_ERR_OR_ZERO(hwmon_dev); } > + > +static const struct i2c_device_id sbrmi_id[] = { > + {"sbrmi", 0}, > + {} > +}; > +MODULE_DEVICE_TABLE(i2c, sbrmi_id); > + > +static const struct of_device_id __maybe_unused sbrmi_of_match[] = { > + { > + .compatible = "amd,sbrmi", > + }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, sbrmi_of_match); > + > +static struct i2c_driver sbrmi_driver = { > + .class = I2C_CLASS_HWMON, > + .driver = { > + .name = "sbrmi", > + .of_match_table = of_match_ptr(sbrmi_of_match), > + }, > + .probe = sbrmi_probe, > + .id_table = sbrmi_id, > +}; > + > +module_i2c_driver(sbrmi_driver); > + > +MODULE_AUTHOR("Akshay Gupta <akshay.gupta@amd.com>"); > +MODULE_DESCRIPTION("Hwmon driver for AMD SB-RMI emulated sensor"); > +MODULE_LICENSE("GPL"); [naveenk:] Thank you for your comments, we will address your comments and submit v2 soon. > [naveenk:] Regards, Naveenk
[Public] Hi Guenter, Couple of questions inline before we submit the next version. Could you answer them. Regards, Naveenk -----Original Message----- From: Chatradhi, Naveen Krishna <NaveenKrishna.Chatradhi@amd.com> Sent: Tuesday, June 29, 2021 8:36 PM To: Guenter Roeck <linux@roeck-us.net>; linux-hwmon@vger.kernel.org Cc: Gupta, Akshay <Akshay.Gupta@amd.com> Subject: RE: [PATCH 1/3] hwmon: sbrmi: Add support for sbrmi power module [CAUTION: External Email] [AMD Official Use Only] Hi Guenter, -----Original Message----- From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck Sent: Monday, June 28, 2021 8:29 PM To: Chatradhi, Naveen Krishna <NaveenKrishna.Chatradhi@amd.com>; linux-hwmon@vger.kernel.org Cc: Gupta, Akshay <Akshay.Gupta@amd.com> Subject: Re: [PATCH 1/3] hwmon: sbrmi: Add support for sbrmi power module [CAUTION: External Email] On 6/25/21 6:25 AM, Naveen Krishna Chatradhi wrote: > From: Akshay Gupta <Akshay.Gupta@amd.com> > > On AMD platforms the Out-of-band access is provided by Advanced > Platform Management This is a bit too long for checkpatch. [naveenk:] Sure > Link (APML), APML is a SMBus v2.0 compatible 2-wire processor client interface. > APML is also referred as the sideband interface (SBI). > > APML is used to communicate with the Remote Management Interface > (SB-Remote Management Interface (SB-RMI) which provides Soft Mailbox > messages to report power consumption and power limits of the CPU socket. > > - This module add support to read power consumption, > power limit & max power limit and write power limit. > - To instantiate this driver on an AMD CPU with SB-RMI support, > the i2c bus number would be the bus connected from the board > management controller (BMC) to the CPU. > This is a bit vague. Would this driver be instantiated on the host CPU or on the BMC ? [naveenk:] This driver is to be instantiated on a BMC connected to AMD CPU. Will correct the comment. > Signed-off-by: Akshay Gupta <Akshay.Gupta@amd.com> > Signed-off-by: Naveen Krishna Chatradhi <nchatrad@amd.com> > --- > drivers/hwmon/Kconfig | 10 ++ > drivers/hwmon/Makefile | 1 + > drivers/hwmon/sbrmi.c | 394 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 405 insertions(+) > create mode 100644 drivers/hwmon/sbrmi.c > > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index > 87624902ea80..d1813ea8382c 100644 > --- a/drivers/hwmon/Kconfig > +++ b/drivers/hwmon/Kconfig > @@ -1551,6 +1551,16 @@ config SENSORS_SBTSI > This driver can also be built as a module. If so, the module will > be called sbtsi_temp. > > +config SENSORS_SBRMI > + tristate "Emulated SB-RMI sensor" > + depends on I2C > + help > + If you say yes here you get support for emulated RMI > + sensors on AMD SoCs with APML interface connected to a BMC device. > + > + This driver can also be built as a module. If so, the module will > + be called sbrmi. > + > config SENSORS_SHT15 > tristate "Sensiron humidity and temperature sensors. SHT15 and compat." > depends on GPIOLIB || COMPILE_TEST diff --git > a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index > 59e78bc212cf..8031acf58936 100644 > --- a/drivers/hwmon/Makefile > +++ b/drivers/hwmon/Makefile > @@ -164,6 +164,7 @@ obj-$(CONFIG_SENSORS_PWM_FAN) += pwm-fan.o > obj-$(CONFIG_SENSORS_RASPBERRYPI_HWMON) += raspberrypi-hwmon.o > obj-$(CONFIG_SENSORS_S3C) += s3c-hwmon.o > obj-$(CONFIG_SENSORS_SBTSI) += sbtsi_temp.o > +obj-$(CONFIG_SENSORS_SBRMI) += sbrmi.o > obj-$(CONFIG_SENSORS_SCH56XX_COMMON)+= sch56xx-common.o > obj-$(CONFIG_SENSORS_SCH5627) += sch5627.o > obj-$(CONFIG_SENSORS_SCH5636) += sch5636.o > diff --git a/drivers/hwmon/sbrmi.c b/drivers/hwmon/sbrmi.c new file > mode 100644 index 000000000000..c35829513459 > --- /dev/null > +++ b/drivers/hwmon/sbrmi.c > @@ -0,0 +1,394 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * sbrmi.c - hwmon driver for a SB-RMI mailbox > + * compliant AMD SoC device. > + * > + * Copyright (C) 2020-2021 Advanced Micro Devices, Inc. > + */ > + > +#include <linux/err.h> > +#include <linux/hwmon.h> > +#include <linux/i2c.h> > +#include <linux/init.h> > +#include <linux/module.h> > +#include <linux/mutex.h> > +#include <linux/of.h> > +#include <linux/of_device.h> I don't immediately see why this include is needed. > +#include <asm-generic/ioctl.h> This looks wrong, and I don't immediately see why it would be needed. > +#include <linux/delay.h> Alphabetic include file order, please. [naveenk:] Sure > + > +/* Do not allow setting negative power limit */ #define SBRMI_PWR_MIN > +0 > +/* Mask for Status Register bit[1] */ #define SW_ALERT_MASK 0x2 > + Please always use #define<space>DEFINITION<tab>value ^^^^^ > +/* Software Interrupt for triggering */ > +#define START_CMD 0x80 > +#define TRIGGER_MAILBOX 0x01 > + > +/* > + * SB-RMI supports soft mailbox service request to MP1 (power > +management > + * firmware) through SBRMI inbound/outbound message registers. > + * SB-RMI message IDs > + */ > +enum sbrmi_msg_id { > + SBRMI_READ_PKG_PWR_CONSUMPTION = 0x1, > + SBRMI_WRITE_PKG_PWR_LIMIT, > + SBRMI_READ_PKG_PWR_LIMIT, > + SBRMI_READ_PKG_MAX_PWR_LIMIT, > +}; > + > +/* SB-RMI registers */ > +enum sbrmi_reg { > + SBRMI_CTRL = 0x01, > + SBRMI_STATUS, > + SBRMI_OUTBNDMSG0 = 0x30, > + SBRMI_OUTBNDMSG1, > + SBRMI_OUTBNDMSG2, > + SBRMI_OUTBNDMSG3, > + SBRMI_OUTBNDMSG4, > + SBRMI_OUTBNDMSG5, > + SBRMI_OUTBNDMSG6, > + SBRMI_OUTBNDMSG7, > + SBRMI_INBNDMSG0, > + SBRMI_INBNDMSG1, > + SBRMI_INBNDMSG2, > + SBRMI_INBNDMSG3, > + SBRMI_INBNDMSG4, > + SBRMI_INBNDMSG5, > + SBRMI_INBNDMSG6, > + SBRMI_INBNDMSG7, > + SBRMI_SW_INTERRUPT, > +}; > + > +/* > + * Each client has this additional data */ Please be consistent with comments: This does not really need to be a multi-line comment. While that does not really matter, you use a single-line comment to describe the next structure. Please make it both either single-line or multi-line. > +struct sbrmi_data { > + struct i2c_client *client; > + struct mutex lock; > +}; > + > +/* Mailbox message data format */ > +union mailbox_word { > + u8 bytes[4]; > + u32 value; That strongly suggests that the driver will only work on either little-endian or big-endian systems, depending on the byte order of transfers. Please restrict it accordingly. > +}; > + > +struct sbrmi_mailbox_msg { > + u8 cmd; > + bool read; > + union mailbox_word data_in; > + union mailbox_word data_out; > +}; > + > +static int print_mailbox_error(struct sbrmi_data *data) { Nit> Many functions only use data>client and, in some cases, dereference Nit> it several times. It might be easier to just pass 'client'. [naveenk:] Sure > + int status; > + > + /* Mailbox error code will be written by Firmware in > + * SBRMI::OutBndMsg_inst7 (SBRMI_x37) > + */ /* * Please use standard multi-line comments. Applies to entire driver. */ [naveenk:] Sure > + status = i2c_smbus_read_byte_data(data->client, SBRMI_OUTBNDMSG7); > + if (status < 0) { > + pr_err("SMBUS translation failed\n"); > + return status; > + } > + > + switch (status) { > + case 0x0: /* Success */ > + break; > + case 0x1: > + pr_err("Mailbox message command is aborted\n"); > + break; > + case 0x2: > + pr_err("Unknown mailbox message\n"); > + break; > + case 0x3: > + pr_err("Invalid core is specified in mailbox message parameters\n"); > + break; > + default: > + pr_err("Unknown Error\n"); > + } Is this noise necessary ? I am concerned that, if it occurs, it would be persistent and fill up the kernel log with noise. [naveenk:] These are firmware defined error codes, can we change them to pr_debug and keep them ? > + > + return status; Error codes are supposed to be negative and standard Linux error codes. Please convert the above errors to standard Linux error codes. > +} > + > +static int sbrmi_enable_alert(struct sbrmi_data *data) { > + int ctrl; > + > + /* Enable the SB-RMI Software alert status > + * by writing 0 to bit 4 of Control register(0x1) > + */ > + ctrl = i2c_smbus_read_byte_data(data->client, SBRMI_CTRL); > + if (ctrl < 0) > + return ctrl; > + > + if (ctrl & 0x10) { > + ctrl &= ~0x10; > + return i2c_smbus_write_byte_data(data->client, > + SBRMI_CTRL, ctrl); > + } > + > + return 0; > +} > + > +static int rmi_mailbox_xfer(struct sbrmi_data *data, > + struct sbrmi_mailbox_msg *msg) { > + union mailbox_word output, input; > + int i, err = 0, retry = 10; Initializing 'err' is unnecessary. > + int sw_status; > + > + mutex_lock(&data->lock); > + > + err = sbrmi_enable_alert(data); > + if (err < 0) > + goto exit_unlock; > + > + /* Indicate firmware a command is to be serviced */ > + err = i2c_smbus_write_byte_data(data->client, > + SBRMI_INBNDMSG7, START_CMD); > + if (err < 0) > + goto exit_unlock; > + > + /* Write the command to SBRMI::InBndMsg_inst0 */ > + err = i2c_smbus_write_byte_data(data->client, > + SBRMI_INBNDMSG0, msg->cmd); > + if (err < 0) > + goto exit_mod; > + > + /* > + * For both read and write the initiator (BMC) writes > + * Command Data In[31:0] to SBRMI::InBndMsg_inst[4:1] > + * SBRMI_x3C(MSB):SBRMI_x39(LSB) > + */ > + input = msg->data_in; > + for (i = 0; i < 3; i++) { This writes 3 bytes. Is that on purpose ? If so please explain since the above suggests that 4 bytes should be written. [naveenk:] this was a mistake, it has to be 4. > + err = i2c_smbus_write_byte_data(data->client, > + (SBRMI_INBNDMSG1 + i), Unnecessary ( ) > + input.bytes[i]); > + if (err < 0) > + goto exit_mod; > + } > + > + /* > + * Write 0x01 to SBRMI::SoftwareInterrupt to notify firmware to > + * perform the requested read or write command > + */ > + err = i2c_smbus_write_byte_data(data->client, > + SBRMI_SW_INTERRUPT, TRIGGER_MAILBOX); > + if (err < 0) > + goto exit_mod; > + > + /* > + * Firmware will write SBRMI::Status[SwAlertSts]=1 to generate > + * an ALERT (if enabled) to initiator (BMC) to indicate completion > + * of the requested command > + */ > + do { > + sw_status = i2c_smbus_read_byte_data(data->client, > + SBRMI_STATUS); > + if (sw_status < 0) { > + err = sw_status; > + goto exit_mod; > + } > + if (sw_status & SW_ALERT_MASK) > + break; > + usleep_range(50, 100); > + } while (retry--); > + > + if (retry < 0) { > + pr_err("Firmware fail to indicate command > + colmpletion\n"); completion > + err = -1; > + goto exit_mod; > + } > + > + /* > + * For a read operation, the initiator (BMC) reads the firmware response > + * Command Data Out[31:0] from SBRMI::OutBndMsg_inst[4:1] > + * {SBRMI_x34(MSB):SBRMI_x31(LSB)}. > + */ > + if (msg->read) { > + for (i = 0; i < 4; i++) { > + output.bytes[i] = > + i2c_smbus_read_byte_data(data->client, > + > + (SBRMI_OUTBNDMSG1 + i)); Unnecessary (). > + if (output.bytes[i] < 0) { output.bytes is defined as u8. This will not catch errors. > + err = output.bytes[i]; > + goto exit_mod; > + } > + } > + } > + msg->data_out = output; > + > + /* > + * BMC must write 1'b1 to SBRMI::Status[SwAlertSts] to clear the > + * ALERT to initiator > + */ > + err = i2c_smbus_write_byte_data(data->client, SBRMI_STATUS, > + (sw_status | SW_ALERT_MASK)); Unnecessary (). > + > +exit_mod: > + if (err < 0) > + pr_err("SMBUS translation failed\n"); > + else > + err = print_mailbox_error(data); > +exit_unlock: > + mutex_unlock(&data->lock); > + return err; > +} > + > +static int sbrmi_read(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long *val) { > + struct sbrmi_data *data = dev_get_drvdata(dev); > + struct sbrmi_mailbox_msg msg = { 0 }; > + int ret; > + > + if (type != hwmon_power) > + return -EINVAL; > + > + msg.read = true; > + switch (attr) { > + case hwmon_power_input: > + msg.cmd = SBRMI_READ_PKG_PWR_CONSUMPTION; > + ret = rmi_mailbox_xfer(data, &msg); > + break; > + case hwmon_power_cap: > + msg.cmd = SBRMI_READ_PKG_PWR_LIMIT; > + ret = rmi_mailbox_xfer(data, &msg); > + break; > + case hwmon_power_cap_max: > + msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; > + ret = rmi_mailbox_xfer(data, &msg); > + break; > + default: > + return -EINVAL; > + } > + /* > + * hwmon power attributes are in microWatt > + */ > + *val = (long)msg.data_out.value * 1000; > + return ret; > +} > + > +static int sbrmi_write(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long val) { > + struct sbrmi_data *data = dev_get_drvdata(dev); > + struct sbrmi_mailbox_msg msg = { 0 }; > + > + if (type != hwmon_power && attr != hwmon_power_cap) > + return -EINVAL; > + /* > + * hwmon power attributes are in microWatt > + * mailbox read/write is in mWatt > + */ > + val /= 1000; > + > + msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; > + msg.data_in.value = 0; > + msg.read = true; > + rmi_mailbox_xfer(data, &msg); > + > + val = clamp_val(val, SBRMI_PWR_MIN, msg.data_out.value); > + > + msg.cmd = SBRMI_WRITE_PKG_PWR_LIMIT; > + msg.data_in.value = val; > + msg.read = false; > + > + return rmi_mailbox_xfer(data, &msg); } > + > +static umode_t sbrmi_is_visible(const void *data, > + enum hwmon_sensor_types type, > + u32 attr, int channel) { > + switch (type) { > + case hwmon_power: > + switch (attr) { > + case hwmon_power_input: > + case hwmon_power_cap_max: > + return 0444; > + case hwmon_power_cap: > + return 0644; > + } > + break; > + default: > + break; > + } > + return 0; > +} > + > +static const struct hwmon_channel_info *sbrmi_info[] = { > + HWMON_CHANNEL_INFO(power, > + HWMON_P_INPUT | HWMON_P_CAP | HWMON_P_CAP_MAX), > + NULL > +}; > + > +static const struct hwmon_ops sbrmi_hwmon_ops = { > + .is_visible = sbrmi_is_visible, > + .read = sbrmi_read, > + .write = sbrmi_write, > +}; > + > +static const struct hwmon_chip_info sbrmi_chip_info = { > + .ops = &sbrmi_hwmon_ops, > + .info = sbrmi_info, > +}; > + > +static int sbrmi_probe(struct i2c_client *client, > + const struct i2c_device_id *id) { > + struct device *dev = &client->dev; > + struct device *hwmon_dev; > + struct sbrmi_data *data; > + > + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { > + dev_err(&client->dev, "adapter does not support true > + I2C\n"); Why would that matter? It only uses SMBus functions. [naveenk:] yes, will remove this. > + return -ENODEV; > + } > + > + data = devm_kzalloc(dev, sizeof(struct sbrmi_data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->client = client; > + mutex_init(&data->lock); > + > + hwmon_dev = devm_hwmon_device_register_with_info(dev, > + client->name, data, > + > + &sbrmi_chip_info, NULL); > + > + return PTR_ERR_OR_ZERO(hwmon_dev); } > + > +static const struct i2c_device_id sbrmi_id[] = { > + {"sbrmi", 0}, > + {} > +}; > +MODULE_DEVICE_TABLE(i2c, sbrmi_id); > + > +static const struct of_device_id __maybe_unused sbrmi_of_match[] = { > + { > + .compatible = "amd,sbrmi", > + }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, sbrmi_of_match); > + > +static struct i2c_driver sbrmi_driver = { > + .class = I2C_CLASS_HWMON, > + .driver = { > + .name = "sbrmi", > + .of_match_table = of_match_ptr(sbrmi_of_match), > + }, > + .probe = sbrmi_probe, > + .id_table = sbrmi_id, > +}; > + > +module_i2c_driver(sbrmi_driver); > + > +MODULE_AUTHOR("Akshay Gupta <akshay.gupta@amd.com>"); > +MODULE_DESCRIPTION("Hwmon driver for AMD SB-RMI emulated sensor"); > +MODULE_LICENSE("GPL"); [naveenk:] Thank you for your comments, we will address your comments and submit v2 soon. > [naveenk:] Regards, Naveenk
On 7/7/21 7:14 AM, Chatradhi, Naveen Krishna wrote: > [Public] > > Hi Guenter, > > Couple of questions inline before we submit the next version. Could you answer them. > > Regards, > Naveenk > > -----Original Message----- > From: Chatradhi, Naveen Krishna <NaveenKrishna.Chatradhi@amd.com> > Sent: Tuesday, June 29, 2021 8:36 PM > To: Guenter Roeck <linux@roeck-us.net>; linux-hwmon@vger.kernel.org > Cc: Gupta, Akshay <Akshay.Gupta@amd.com> > Subject: RE: [PATCH 1/3] hwmon: sbrmi: Add support for sbrmi power module > > [CAUTION: External Email] > > [AMD Official Use Only] > > Hi Guenter, > > -----Original Message----- > From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck > Sent: Monday, June 28, 2021 8:29 PM > To: Chatradhi, Naveen Krishna <NaveenKrishna.Chatradhi@amd.com>; linux-hwmon@vger.kernel.org > Cc: Gupta, Akshay <Akshay.Gupta@amd.com> > Subject: Re: [PATCH 1/3] hwmon: sbrmi: Add support for sbrmi power module > > [CAUTION: External Email] > > On 6/25/21 6:25 AM, Naveen Krishna Chatradhi wrote: >> From: Akshay Gupta <Akshay.Gupta@amd.com> >> >> On AMD platforms the Out-of-band access is provided by Advanced >> Platform Management > > This is a bit too long for checkpatch. > [naveenk:] Sure > >> Link (APML), APML is a SMBus v2.0 compatible 2-wire processor client interface. >> APML is also referred as the sideband interface (SBI). >> >> APML is used to communicate with the Remote Management Interface >> (SB-Remote Management Interface (SB-RMI) which provides Soft Mailbox >> messages to report power consumption and power limits of the CPU socket. >> >> - This module add support to read power consumption, >> power limit & max power limit and write power limit. >> - To instantiate this driver on an AMD CPU with SB-RMI support, >> the i2c bus number would be the bus connected from the board >> management controller (BMC) to the CPU. >> > > This is a bit vague. Would this driver be instantiated on the host CPU or on the BMC ? > [naveenk:] This driver is to be instantiated on a BMC connected to AMD CPU. Will correct the comment. > >> Signed-off-by: Akshay Gupta <Akshay.Gupta@amd.com> >> Signed-off-by: Naveen Krishna Chatradhi <nchatrad@amd.com> >> --- >> drivers/hwmon/Kconfig | 10 ++ >> drivers/hwmon/Makefile | 1 + >> drivers/hwmon/sbrmi.c | 394 +++++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 405 insertions(+) >> create mode 100644 drivers/hwmon/sbrmi.c >> >> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index >> 87624902ea80..d1813ea8382c 100644 >> --- a/drivers/hwmon/Kconfig >> +++ b/drivers/hwmon/Kconfig >> @@ -1551,6 +1551,16 @@ config SENSORS_SBTSI >> This driver can also be built as a module. If so, the module will >> be called sbtsi_temp. >> >> +config SENSORS_SBRMI >> + tristate "Emulated SB-RMI sensor" >> + depends on I2C >> + help >> + If you say yes here you get support for emulated RMI >> + sensors on AMD SoCs with APML interface connected to a BMC device. >> + >> + This driver can also be built as a module. If so, the module will >> + be called sbrmi. >> + >> config SENSORS_SHT15 >> tristate "Sensiron humidity and temperature sensors. SHT15 and compat." >> depends on GPIOLIB || COMPILE_TEST diff --git >> a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index >> 59e78bc212cf..8031acf58936 100644 >> --- a/drivers/hwmon/Makefile >> +++ b/drivers/hwmon/Makefile >> @@ -164,6 +164,7 @@ obj-$(CONFIG_SENSORS_PWM_FAN) += pwm-fan.o >> obj-$(CONFIG_SENSORS_RASPBERRYPI_HWMON) += raspberrypi-hwmon.o >> obj-$(CONFIG_SENSORS_S3C) += s3c-hwmon.o >> obj-$(CONFIG_SENSORS_SBTSI) += sbtsi_temp.o >> +obj-$(CONFIG_SENSORS_SBRMI) += sbrmi.o >> obj-$(CONFIG_SENSORS_SCH56XX_COMMON)+= sch56xx-common.o >> obj-$(CONFIG_SENSORS_SCH5627) += sch5627.o >> obj-$(CONFIG_SENSORS_SCH5636) += sch5636.o >> diff --git a/drivers/hwmon/sbrmi.c b/drivers/hwmon/sbrmi.c new file >> mode 100644 index 000000000000..c35829513459 >> --- /dev/null >> +++ b/drivers/hwmon/sbrmi.c >> @@ -0,0 +1,394 @@ >> +// SPDX-License-Identifier: GPL-2.0-or-later >> +/* >> + * sbrmi.c - hwmon driver for a SB-RMI mailbox >> + * compliant AMD SoC device. >> + * >> + * Copyright (C) 2020-2021 Advanced Micro Devices, Inc. >> + */ >> + >> +#include <linux/err.h> >> +#include <linux/hwmon.h> >> +#include <linux/i2c.h> >> +#include <linux/init.h> >> +#include <linux/module.h> >> +#include <linux/mutex.h> >> +#include <linux/of.h> >> +#include <linux/of_device.h> > > I don't immediately see why this include is needed. > >> +#include <asm-generic/ioctl.h> > > This looks wrong, and I don't immediately see why it would be needed. > >> +#include <linux/delay.h> > > Alphabetic include file order, please. > [naveenk:] Sure >> + >> +/* Do not allow setting negative power limit */ #define SBRMI_PWR_MIN >> +0 >> +/* Mask for Status Register bit[1] */ #define SW_ALERT_MASK 0x2 >> + > > Please always use > > #define<space>DEFINITION<tab>value > ^^^^^ > >> +/* Software Interrupt for triggering */ >> +#define START_CMD 0x80 >> +#define TRIGGER_MAILBOX 0x01 >> + >> +/* >> + * SB-RMI supports soft mailbox service request to MP1 (power >> +management >> + * firmware) through SBRMI inbound/outbound message registers. >> + * SB-RMI message IDs >> + */ >> +enum sbrmi_msg_id { >> + SBRMI_READ_PKG_PWR_CONSUMPTION = 0x1, >> + SBRMI_WRITE_PKG_PWR_LIMIT, >> + SBRMI_READ_PKG_PWR_LIMIT, >> + SBRMI_READ_PKG_MAX_PWR_LIMIT, >> +}; >> + >> +/* SB-RMI registers */ >> +enum sbrmi_reg { >> + SBRMI_CTRL = 0x01, >> + SBRMI_STATUS, >> + SBRMI_OUTBNDMSG0 = 0x30, >> + SBRMI_OUTBNDMSG1, >> + SBRMI_OUTBNDMSG2, >> + SBRMI_OUTBNDMSG3, >> + SBRMI_OUTBNDMSG4, >> + SBRMI_OUTBNDMSG5, >> + SBRMI_OUTBNDMSG6, >> + SBRMI_OUTBNDMSG7, >> + SBRMI_INBNDMSG0, >> + SBRMI_INBNDMSG1, >> + SBRMI_INBNDMSG2, >> + SBRMI_INBNDMSG3, >> + SBRMI_INBNDMSG4, >> + SBRMI_INBNDMSG5, >> + SBRMI_INBNDMSG6, >> + SBRMI_INBNDMSG7, >> + SBRMI_SW_INTERRUPT, >> +}; >> + >> +/* >> + * Each client has this additional data */ > > Please be consistent with comments: This does not really need to be a multi-line comment. While that does not really matter, you use a single-line comment to describe the next structure. Please make it both either single-line or multi-line. > >> +struct sbrmi_data { >> + struct i2c_client *client; >> + struct mutex lock; >> +}; >> + >> +/* Mailbox message data format */ >> +union mailbox_word { >> + u8 bytes[4]; >> + u32 value; > > That strongly suggests that the driver will only work on either little-endian or big-endian systems, depending on the byte order of transfers. Please restrict it accordingly. > >> +}; >> + >> +struct sbrmi_mailbox_msg { >> + u8 cmd; >> + bool read; >> + union mailbox_word data_in; >> + union mailbox_word data_out; >> +}; >> + >> +static int print_mailbox_error(struct sbrmi_data *data) { > > Nit> Many functions only use data>client and, in some cases, dereference > Nit> it > several times. It might be easier to just pass 'client'. > [naveenk:] Sure > >> + int status; >> + >> + /* Mailbox error code will be written by Firmware in >> + * SBRMI::OutBndMsg_inst7 (SBRMI_x37) >> + */ > > /* > * Please use standard multi-line comments. Applies to entire driver. > */ > [naveenk:] Sure > >> + status = i2c_smbus_read_byte_data(data->client, SBRMI_OUTBNDMSG7); >> + if (status < 0) { >> + pr_err("SMBUS translation failed\n"); >> + return status; >> + } >> + >> + switch (status) { >> + case 0x0: /* Success */ >> + break; >> + case 0x1: >> + pr_err("Mailbox message command is aborted\n"); >> + break; >> + case 0x2: >> + pr_err("Unknown mailbox message\n"); >> + break; >> + case 0x3: >> + pr_err("Invalid core is specified in mailbox message parameters\n"); >> + break; >> + default: >> + pr_err("Unknown Error\n"); >> + } > > Is this noise necessary ? I am concerned that, if it occurs, it would be persistent and fill up the kernel log with noise. > [naveenk:] These are firmware defined error codes, can we change them to pr_debug and keep them ? > pr_debug is ok, but ... >> + >> + return status; > > Error codes are supposed to be negative and standard Linux error codes. > Please convert the above errors to standard Linux error codes. > you'll still need to convert the error codes to standard error codes. This is the only question I found. Please let me know if I missed something. Thanks, Guenter >> +} >> + >> +static int sbrmi_enable_alert(struct sbrmi_data *data) { >> + int ctrl; >> + >> + /* Enable the SB-RMI Software alert status >> + * by writing 0 to bit 4 of Control register(0x1) >> + */ >> + ctrl = i2c_smbus_read_byte_data(data->client, SBRMI_CTRL); >> + if (ctrl < 0) >> + return ctrl; >> + >> + if (ctrl & 0x10) { >> + ctrl &= ~0x10; >> + return i2c_smbus_write_byte_data(data->client, >> + SBRMI_CTRL, ctrl); >> + } >> + >> + return 0; >> +} >> + >> +static int rmi_mailbox_xfer(struct sbrmi_data *data, >> + struct sbrmi_mailbox_msg *msg) { >> + union mailbox_word output, input; >> + int i, err = 0, retry = 10; > > Initializing 'err' is unnecessary. > >> + int sw_status; >> + >> + mutex_lock(&data->lock); >> + >> + err = sbrmi_enable_alert(data); >> + if (err < 0) >> + goto exit_unlock; >> + >> + /* Indicate firmware a command is to be serviced */ >> + err = i2c_smbus_write_byte_data(data->client, >> + SBRMI_INBNDMSG7, START_CMD); >> + if (err < 0) >> + goto exit_unlock; >> + >> + /* Write the command to SBRMI::InBndMsg_inst0 */ >> + err = i2c_smbus_write_byte_data(data->client, >> + SBRMI_INBNDMSG0, msg->cmd); >> + if (err < 0) >> + goto exit_mod; >> + >> + /* >> + * For both read and write the initiator (BMC) writes >> + * Command Data In[31:0] to SBRMI::InBndMsg_inst[4:1] >> + * SBRMI_x3C(MSB):SBRMI_x39(LSB) >> + */ >> + input = msg->data_in; >> + for (i = 0; i < 3; i++) { > > This writes 3 bytes. Is that on purpose ? If so please explain since the above suggests that 4 bytes should be written. > [naveenk:] this was a mistake, it has to be 4. > >> + err = i2c_smbus_write_byte_data(data->client, >> + (SBRMI_INBNDMSG1 + i), > > Unnecessary ( ) > >> + input.bytes[i]); >> + if (err < 0) >> + goto exit_mod; >> + } >> + >> + /* >> + * Write 0x01 to SBRMI::SoftwareInterrupt to notify firmware to >> + * perform the requested read or write command >> + */ >> + err = i2c_smbus_write_byte_data(data->client, >> + SBRMI_SW_INTERRUPT, TRIGGER_MAILBOX); >> + if (err < 0) >> + goto exit_mod; >> + >> + /* >> + * Firmware will write SBRMI::Status[SwAlertSts]=1 to generate >> + * an ALERT (if enabled) to initiator (BMC) to indicate completion >> + * of the requested command >> + */ >> + do { >> + sw_status = i2c_smbus_read_byte_data(data->client, >> + SBRMI_STATUS); >> + if (sw_status < 0) { >> + err = sw_status; >> + goto exit_mod; >> + } >> + if (sw_status & SW_ALERT_MASK) >> + break; >> + usleep_range(50, 100); >> + } while (retry--); >> + >> + if (retry < 0) { >> + pr_err("Firmware fail to indicate command >> + colmpletion\n"); > > completion > >> + err = -1; >> + goto exit_mod; >> + } >> + >> + /* >> + * For a read operation, the initiator (BMC) reads the firmware response >> + * Command Data Out[31:0] from SBRMI::OutBndMsg_inst[4:1] >> + * {SBRMI_x34(MSB):SBRMI_x31(LSB)}. >> + */ >> + if (msg->read) { >> + for (i = 0; i < 4; i++) { >> + output.bytes[i] = >> + i2c_smbus_read_byte_data(data->client, >> + >> + (SBRMI_OUTBNDMSG1 + i)); > > Unnecessary (). > >> + if (output.bytes[i] < 0) { > > output.bytes is defined as u8. This will not catch errors. > >> + err = output.bytes[i]; >> + goto exit_mod; >> + } >> + } >> + } >> + msg->data_out = output; >> + >> + /* >> + * BMC must write 1'b1 to SBRMI::Status[SwAlertSts] to clear the >> + * ALERT to initiator >> + */ >> + err = i2c_smbus_write_byte_data(data->client, SBRMI_STATUS, >> + (sw_status | SW_ALERT_MASK)); > > Unnecessary (). > >> + >> +exit_mod: >> + if (err < 0) >> + pr_err("SMBUS translation failed\n"); >> + else >> + err = print_mailbox_error(data); >> +exit_unlock: >> + mutex_unlock(&data->lock); >> + return err; >> +} >> + >> +static int sbrmi_read(struct device *dev, enum hwmon_sensor_types type, >> + u32 attr, int channel, long *val) { >> + struct sbrmi_data *data = dev_get_drvdata(dev); >> + struct sbrmi_mailbox_msg msg = { 0 }; >> + int ret; >> + >> + if (type != hwmon_power) >> + return -EINVAL; >> + >> + msg.read = true; >> + switch (attr) { >> + case hwmon_power_input: >> + msg.cmd = SBRMI_READ_PKG_PWR_CONSUMPTION; >> + ret = rmi_mailbox_xfer(data, &msg); >> + break; >> + case hwmon_power_cap: >> + msg.cmd = SBRMI_READ_PKG_PWR_LIMIT; >> + ret = rmi_mailbox_xfer(data, &msg); >> + break; >> + case hwmon_power_cap_max: >> + msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; >> + ret = rmi_mailbox_xfer(data, &msg); >> + break; >> + default: >> + return -EINVAL; >> + } >> + /* >> + * hwmon power attributes are in microWatt >> + */ >> + *val = (long)msg.data_out.value * 1000; >> + return ret; >> +} >> + >> +static int sbrmi_write(struct device *dev, enum hwmon_sensor_types type, >> + u32 attr, int channel, long val) { >> + struct sbrmi_data *data = dev_get_drvdata(dev); >> + struct sbrmi_mailbox_msg msg = { 0 }; >> + >> + if (type != hwmon_power && attr != hwmon_power_cap) >> + return -EINVAL; >> + /* >> + * hwmon power attributes are in microWatt >> + * mailbox read/write is in mWatt >> + */ >> + val /= 1000; >> + >> + msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; >> + msg.data_in.value = 0; >> + msg.read = true; >> + rmi_mailbox_xfer(data, &msg); >> + >> + val = clamp_val(val, SBRMI_PWR_MIN, msg.data_out.value); >> + >> + msg.cmd = SBRMI_WRITE_PKG_PWR_LIMIT; >> + msg.data_in.value = val; >> + msg.read = false; >> + >> + return rmi_mailbox_xfer(data, &msg); } >> + >> +static umode_t sbrmi_is_visible(const void *data, >> + enum hwmon_sensor_types type, >> + u32 attr, int channel) { >> + switch (type) { >> + case hwmon_power: >> + switch (attr) { >> + case hwmon_power_input: >> + case hwmon_power_cap_max: >> + return 0444; >> + case hwmon_power_cap: >> + return 0644; >> + } >> + break; >> + default: >> + break; >> + } >> + return 0; >> +} >> + >> +static const struct hwmon_channel_info *sbrmi_info[] = { >> + HWMON_CHANNEL_INFO(power, >> + HWMON_P_INPUT | HWMON_P_CAP | HWMON_P_CAP_MAX), >> + NULL >> +}; >> + >> +static const struct hwmon_ops sbrmi_hwmon_ops = { >> + .is_visible = sbrmi_is_visible, >> + .read = sbrmi_read, >> + .write = sbrmi_write, >> +}; >> + >> +static const struct hwmon_chip_info sbrmi_chip_info = { >> + .ops = &sbrmi_hwmon_ops, >> + .info = sbrmi_info, >> +}; >> + >> +static int sbrmi_probe(struct i2c_client *client, >> + const struct i2c_device_id *id) { >> + struct device *dev = &client->dev; >> + struct device *hwmon_dev; >> + struct sbrmi_data *data; >> + >> + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { >> + dev_err(&client->dev, "adapter does not support true >> + I2C\n"); > > Why would that matter? It only uses SMBus functions. > [naveenk:] yes, will remove this. > >> + return -ENODEV; >> + } >> + >> + data = devm_kzalloc(dev, sizeof(struct sbrmi_data), GFP_KERNEL); >> + if (!data) >> + return -ENOMEM; >> + >> + data->client = client; >> + mutex_init(&data->lock); >> + >> + hwmon_dev = devm_hwmon_device_register_with_info(dev, >> + client->name, data, >> + >> + &sbrmi_chip_info, NULL); >> + >> + return PTR_ERR_OR_ZERO(hwmon_dev); } >> + >> +static const struct i2c_device_id sbrmi_id[] = { >> + {"sbrmi", 0}, >> + {} >> +}; >> +MODULE_DEVICE_TABLE(i2c, sbrmi_id); >> + >> +static const struct of_device_id __maybe_unused sbrmi_of_match[] = { >> + { >> + .compatible = "amd,sbrmi", >> + }, >> + { }, >> +}; >> +MODULE_DEVICE_TABLE(of, sbrmi_of_match); >> + >> +static struct i2c_driver sbrmi_driver = { >> + .class = I2C_CLASS_HWMON, >> + .driver = { >> + .name = "sbrmi", >> + .of_match_table = of_match_ptr(sbrmi_of_match), >> + }, >> + .probe = sbrmi_probe, >> + .id_table = sbrmi_id, >> +}; >> + >> +module_i2c_driver(sbrmi_driver); >> + >> +MODULE_AUTHOR("Akshay Gupta <akshay.gupta@amd.com>"); >> +MODULE_DESCRIPTION("Hwmon driver for AMD SB-RMI emulated sensor"); >> +MODULE_LICENSE("GPL"); > [naveenk:] Thank you for your comments, we will address your comments and submit v2 soon. >> > [naveenk:] > Regards, > Naveenk >
[Public] Hi Guenter -----Original Message----- From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck Sent: Wednesday, July 7, 2021 7:52 PM To: Chatradhi, Naveen Krishna <NaveenKrishna.Chatradhi@amd.com>; linux-hwmon@vger.kernel.org Cc: Gupta, Akshay <Akshay.Gupta@amd.com> Subject: Re: [PATCH 1/3] hwmon: sbrmi: Add support for sbrmi power module [CAUTION: External Email] On 7/7/21 7:14 AM, Chatradhi, Naveen Krishna wrote: > [Public] > > Hi Guenter, > > Couple of questions inline before we submit the next version. Could you answer them. [naveenk:] Yes, that was the one. Submitting the next version. Thank you. > > Regards, > Naveenk > > -----Original Message----- > From: Chatradhi, Naveen Krishna <NaveenKrishna.Chatradhi@amd.com> > Sent: Tuesday, June 29, 2021 8:36 PM > To: Guenter Roeck <linux@roeck-us.net>; linux-hwmon@vger.kernel.org > Cc: Gupta, Akshay <Akshay.Gupta@amd.com> > Subject: RE: [PATCH 1/3] hwmon: sbrmi: Add support for sbrmi power > module > > [CAUTION: External Email] > > [AMD Official Use Only] > > Hi Guenter, > > -----Original Message----- > From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck > Sent: Monday, June 28, 2021 8:29 PM > To: Chatradhi, Naveen Krishna <NaveenKrishna.Chatradhi@amd.com>; > linux-hwmon@vger.kernel.org > Cc: Gupta, Akshay <Akshay.Gupta@amd.com> > Subject: Re: [PATCH 1/3] hwmon: sbrmi: Add support for sbrmi power > module > > [CAUTION: External Email] > > On 6/25/21 6:25 AM, Naveen Krishna Chatradhi wrote: >> From: Akshay Gupta <Akshay.Gupta@amd.com> >> >> On AMD platforms the Out-of-band access is provided by Advanced >> Platform Management > > This is a bit too long for checkpatch. > [naveenk:] Sure > >> Link (APML), APML is a SMBus v2.0 compatible 2-wire processor client interface. >> APML is also referred as the sideband interface (SBI). >> >> APML is used to communicate with the Remote Management Interface >> (SB-Remote Management Interface (SB-RMI) which provides Soft Mailbox >> messages to report power consumption and power limits of the CPU socket. >> >> - This module add support to read power consumption, >> power limit & max power limit and write power limit. >> - To instantiate this driver on an AMD CPU with SB-RMI support, >> the i2c bus number would be the bus connected from the board >> management controller (BMC) to the CPU. >> > > This is a bit vague. Would this driver be instantiated on the host CPU or on the BMC ? > [naveenk:] This driver is to be instantiated on a BMC connected to AMD CPU. Will correct the comment. > >> Signed-off-by: Akshay Gupta <Akshay.Gupta@amd.com> >> Signed-off-by: Naveen Krishna Chatradhi <nchatrad@amd.com> >> --- >> drivers/hwmon/Kconfig | 10 ++ >> drivers/hwmon/Makefile | 1 + >> drivers/hwmon/sbrmi.c | 394 +++++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 405 insertions(+) >> create mode 100644 drivers/hwmon/sbrmi.c >> >> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index >> 87624902ea80..d1813ea8382c 100644 >> --- a/drivers/hwmon/Kconfig >> +++ b/drivers/hwmon/Kconfig >> @@ -1551,6 +1551,16 @@ config SENSORS_SBTSI >> This driver can also be built as a module. If so, the module will >> be called sbtsi_temp. >> >> +config SENSORS_SBRMI >> + tristate "Emulated SB-RMI sensor" >> + depends on I2C >> + help >> + If you say yes here you get support for emulated RMI >> + sensors on AMD SoCs with APML interface connected to a BMC device. >> + >> + This driver can also be built as a module. If so, the module will >> + be called sbrmi. >> + >> config SENSORS_SHT15 >> tristate "Sensiron humidity and temperature sensors. SHT15 and compat." >> depends on GPIOLIB || COMPILE_TEST diff --git >> a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index >> 59e78bc212cf..8031acf58936 100644 >> --- a/drivers/hwmon/Makefile >> +++ b/drivers/hwmon/Makefile >> @@ -164,6 +164,7 @@ obj-$(CONFIG_SENSORS_PWM_FAN) += pwm-fan.o >> obj-$(CONFIG_SENSORS_RASPBERRYPI_HWMON) += raspberrypi-hwmon.o >> obj-$(CONFIG_SENSORS_S3C) += s3c-hwmon.o >> obj-$(CONFIG_SENSORS_SBTSI) += sbtsi_temp.o >> +obj-$(CONFIG_SENSORS_SBRMI) += sbrmi.o >> obj-$(CONFIG_SENSORS_SCH56XX_COMMON)+= sch56xx-common.o >> obj-$(CONFIG_SENSORS_SCH5627) += sch5627.o >> obj-$(CONFIG_SENSORS_SCH5636) += sch5636.o >> diff --git a/drivers/hwmon/sbrmi.c b/drivers/hwmon/sbrmi.c new file >> mode 100644 index 000000000000..c35829513459 >> --- /dev/null >> +++ b/drivers/hwmon/sbrmi.c >> @@ -0,0 +1,394 @@ >> +// SPDX-License-Identifier: GPL-2.0-or-later >> +/* >> + * sbrmi.c - hwmon driver for a SB-RMI mailbox >> + * compliant AMD SoC device. >> + * >> + * Copyright (C) 2020-2021 Advanced Micro Devices, Inc. >> + */ >> + >> +#include <linux/err.h> >> +#include <linux/hwmon.h> >> +#include <linux/i2c.h> >> +#include <linux/init.h> >> +#include <linux/module.h> >> +#include <linux/mutex.h> >> +#include <linux/of.h> >> +#include <linux/of_device.h> > > I don't immediately see why this include is needed. > >> +#include <asm-generic/ioctl.h> > > This looks wrong, and I don't immediately see why it would be needed. > >> +#include <linux/delay.h> > > Alphabetic include file order, please. > [naveenk:] Sure >> + >> +/* Do not allow setting negative power limit */ #define >> +SBRMI_PWR_MIN >> +0 >> +/* Mask for Status Register bit[1] */ #define SW_ALERT_MASK 0x2 >> + > > Please always use > > #define<space>DEFINITION<tab>value > ^^^^^ > >> +/* Software Interrupt for triggering */ >> +#define START_CMD 0x80 >> +#define TRIGGER_MAILBOX 0x01 >> + >> +/* >> + * SB-RMI supports soft mailbox service request to MP1 (power >> +management >> + * firmware) through SBRMI inbound/outbound message registers. >> + * SB-RMI message IDs >> + */ >> +enum sbrmi_msg_id { >> + SBRMI_READ_PKG_PWR_CONSUMPTION = 0x1, >> + SBRMI_WRITE_PKG_PWR_LIMIT, >> + SBRMI_READ_PKG_PWR_LIMIT, >> + SBRMI_READ_PKG_MAX_PWR_LIMIT, >> +}; >> + >> +/* SB-RMI registers */ >> +enum sbrmi_reg { >> + SBRMI_CTRL = 0x01, >> + SBRMI_STATUS, >> + SBRMI_OUTBNDMSG0 = 0x30, >> + SBRMI_OUTBNDMSG1, >> + SBRMI_OUTBNDMSG2, >> + SBRMI_OUTBNDMSG3, >> + SBRMI_OUTBNDMSG4, >> + SBRMI_OUTBNDMSG5, >> + SBRMI_OUTBNDMSG6, >> + SBRMI_OUTBNDMSG7, >> + SBRMI_INBNDMSG0, >> + SBRMI_INBNDMSG1, >> + SBRMI_INBNDMSG2, >> + SBRMI_INBNDMSG3, >> + SBRMI_INBNDMSG4, >> + SBRMI_INBNDMSG5, >> + SBRMI_INBNDMSG6, >> + SBRMI_INBNDMSG7, >> + SBRMI_SW_INTERRUPT, >> +}; >> + >> +/* >> + * Each client has this additional data */ > > Please be consistent with comments: This does not really need to be a multi-line comment. While that does not really matter, you use a single-line comment to describe the next structure. Please make it both either single-line or multi-line. > >> +struct sbrmi_data { >> + struct i2c_client *client; >> + struct mutex lock; >> +}; >> + >> +/* Mailbox message data format */ >> +union mailbox_word { >> + u8 bytes[4]; >> + u32 value; > > That strongly suggests that the driver will only work on either little-endian or big-endian systems, depending on the byte order of transfers. Please restrict it accordingly. > >> +}; >> + >> +struct sbrmi_mailbox_msg { >> + u8 cmd; >> + bool read; >> + union mailbox_word data_in; >> + union mailbox_word data_out; >> +}; >> + >> +static int print_mailbox_error(struct sbrmi_data *data) { > > Nit> Many functions only use data>client and, in some cases, > Nit> dereference it > several times. It might be easier to just pass 'client'. > [naveenk:] Sure > >> + int status; >> + >> + /* Mailbox error code will be written by Firmware in >> + * SBRMI::OutBndMsg_inst7 (SBRMI_x37) >> + */ > > /* > * Please use standard multi-line comments. Applies to entire driver. > */ > [naveenk:] Sure > >> + status = i2c_smbus_read_byte_data(data->client, SBRMI_OUTBNDMSG7); >> + if (status < 0) { >> + pr_err("SMBUS translation failed\n"); >> + return status; >> + } >> + >> + switch (status) { >> + case 0x0: /* Success */ >> + break; >> + case 0x1: >> + pr_err("Mailbox message command is aborted\n"); >> + break; >> + case 0x2: >> + pr_err("Unknown mailbox message\n"); >> + break; >> + case 0x3: >> + pr_err("Invalid core is specified in mailbox message parameters\n"); >> + break; >> + default: >> + pr_err("Unknown Error\n"); >> + } > > Is this noise necessary ? I am concerned that, if it occurs, it would be persistent and fill up the kernel log with noise. > [naveenk:] These are firmware defined error codes, can we change them to pr_debug and keep them ? > pr_debug is ok, but ... >> + >> + return status; > > Error codes are supposed to be negative and standard Linux error codes. > Please convert the above errors to standard Linux error codes. > you'll still need to convert the error codes to standard error codes. This is the only question I found. Please let me know if I missed something. Thanks, Guenter >> +} >> + >> +static int sbrmi_enable_alert(struct sbrmi_data *data) { >> + int ctrl; >> + >> + /* Enable the SB-RMI Software alert status >> + * by writing 0 to bit 4 of Control register(0x1) >> + */ >> + ctrl = i2c_smbus_read_byte_data(data->client, SBRMI_CTRL); >> + if (ctrl < 0) >> + return ctrl; >> + >> + if (ctrl & 0x10) { >> + ctrl &= ~0x10; >> + return i2c_smbus_write_byte_data(data->client, >> + SBRMI_CTRL, ctrl); >> + } >> + >> + return 0; >> +} >> + >> +static int rmi_mailbox_xfer(struct sbrmi_data *data, >> + struct sbrmi_mailbox_msg *msg) { >> + union mailbox_word output, input; >> + int i, err = 0, retry = 10; > > Initializing 'err' is unnecessary. > >> + int sw_status; >> + >> + mutex_lock(&data->lock); >> + >> + err = sbrmi_enable_alert(data); >> + if (err < 0) >> + goto exit_unlock; >> + >> + /* Indicate firmware a command is to be serviced */ >> + err = i2c_smbus_write_byte_data(data->client, >> + SBRMI_INBNDMSG7, START_CMD); >> + if (err < 0) >> + goto exit_unlock; >> + >> + /* Write the command to SBRMI::InBndMsg_inst0 */ >> + err = i2c_smbus_write_byte_data(data->client, >> + SBRMI_INBNDMSG0, msg->cmd); >> + if (err < 0) >> + goto exit_mod; >> + >> + /* >> + * For both read and write the initiator (BMC) writes >> + * Command Data In[31:0] to SBRMI::InBndMsg_inst[4:1] >> + * SBRMI_x3C(MSB):SBRMI_x39(LSB) >> + */ >> + input = msg->data_in; >> + for (i = 0; i < 3; i++) { > > This writes 3 bytes. Is that on purpose ? If so please explain since the above suggests that 4 bytes should be written. > [naveenk:] this was a mistake, it has to be 4. > >> + err = i2c_smbus_write_byte_data(data->client, >> + (SBRMI_INBNDMSG1 + i), > > Unnecessary ( ) > >> + input.bytes[i]); >> + if (err < 0) >> + goto exit_mod; >> + } >> + >> + /* >> + * Write 0x01 to SBRMI::SoftwareInterrupt to notify firmware to >> + * perform the requested read or write command >> + */ >> + err = i2c_smbus_write_byte_data(data->client, >> + SBRMI_SW_INTERRUPT, TRIGGER_MAILBOX); >> + if (err < 0) >> + goto exit_mod; >> + >> + /* >> + * Firmware will write SBRMI::Status[SwAlertSts]=1 to generate >> + * an ALERT (if enabled) to initiator (BMC) to indicate completion >> + * of the requested command >> + */ >> + do { >> + sw_status = i2c_smbus_read_byte_data(data->client, >> + SBRMI_STATUS); >> + if (sw_status < 0) { >> + err = sw_status; >> + goto exit_mod; >> + } >> + if (sw_status & SW_ALERT_MASK) >> + break; >> + usleep_range(50, 100); >> + } while (retry--); >> + >> + if (retry < 0) { >> + pr_err("Firmware fail to indicate command >> + colmpletion\n"); > > completion > >> + err = -1; >> + goto exit_mod; >> + } >> + >> + /* >> + * For a read operation, the initiator (BMC) reads the firmware response >> + * Command Data Out[31:0] from SBRMI::OutBndMsg_inst[4:1] >> + * {SBRMI_x34(MSB):SBRMI_x31(LSB)}. >> + */ >> + if (msg->read) { >> + for (i = 0; i < 4; i++) { >> + output.bytes[i] = >> + i2c_smbus_read_byte_data(data->client, >> + >> + (SBRMI_OUTBNDMSG1 + i)); > > Unnecessary (). > >> + if (output.bytes[i] < 0) { > > output.bytes is defined as u8. This will not catch errors. > >> + err = output.bytes[i]; >> + goto exit_mod; >> + } >> + } >> + } >> + msg->data_out = output; >> + >> + /* >> + * BMC must write 1'b1 to SBRMI::Status[SwAlertSts] to clear the >> + * ALERT to initiator >> + */ >> + err = i2c_smbus_write_byte_data(data->client, SBRMI_STATUS, >> + (sw_status | SW_ALERT_MASK)); > > Unnecessary (). > >> + >> +exit_mod: >> + if (err < 0) >> + pr_err("SMBUS translation failed\n"); >> + else >> + err = print_mailbox_error(data); >> +exit_unlock: >> + mutex_unlock(&data->lock); >> + return err; >> +} >> + >> +static int sbrmi_read(struct device *dev, enum hwmon_sensor_types type, >> + u32 attr, int channel, long *val) { >> + struct sbrmi_data *data = dev_get_drvdata(dev); >> + struct sbrmi_mailbox_msg msg = { 0 }; >> + int ret; >> + >> + if (type != hwmon_power) >> + return -EINVAL; >> + >> + msg.read = true; >> + switch (attr) { >> + case hwmon_power_input: >> + msg.cmd = SBRMI_READ_PKG_PWR_CONSUMPTION; >> + ret = rmi_mailbox_xfer(data, &msg); >> + break; >> + case hwmon_power_cap: >> + msg.cmd = SBRMI_READ_PKG_PWR_LIMIT; >> + ret = rmi_mailbox_xfer(data, &msg); >> + break; >> + case hwmon_power_cap_max: >> + msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; >> + ret = rmi_mailbox_xfer(data, &msg); >> + break; >> + default: >> + return -EINVAL; >> + } >> + /* >> + * hwmon power attributes are in microWatt >> + */ >> + *val = (long)msg.data_out.value * 1000; >> + return ret; >> +} >> + >> +static int sbrmi_write(struct device *dev, enum hwmon_sensor_types type, >> + u32 attr, int channel, long val) { >> + struct sbrmi_data *data = dev_get_drvdata(dev); >> + struct sbrmi_mailbox_msg msg = { 0 }; >> + >> + if (type != hwmon_power && attr != hwmon_power_cap) >> + return -EINVAL; >> + /* >> + * hwmon power attributes are in microWatt >> + * mailbox read/write is in mWatt >> + */ >> + val /= 1000; >> + >> + msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; >> + msg.data_in.value = 0; >> + msg.read = true; >> + rmi_mailbox_xfer(data, &msg); >> + >> + val = clamp_val(val, SBRMI_PWR_MIN, msg.data_out.value); >> + >> + msg.cmd = SBRMI_WRITE_PKG_PWR_LIMIT; >> + msg.data_in.value = val; >> + msg.read = false; >> + >> + return rmi_mailbox_xfer(data, &msg); } >> + >> +static umode_t sbrmi_is_visible(const void *data, >> + enum hwmon_sensor_types type, >> + u32 attr, int channel) { >> + switch (type) { >> + case hwmon_power: >> + switch (attr) { >> + case hwmon_power_input: >> + case hwmon_power_cap_max: >> + return 0444; >> + case hwmon_power_cap: >> + return 0644; >> + } >> + break; >> + default: >> + break; >> + } >> + return 0; >> +} >> + >> +static const struct hwmon_channel_info *sbrmi_info[] = { >> + HWMON_CHANNEL_INFO(power, >> + HWMON_P_INPUT | HWMON_P_CAP | HWMON_P_CAP_MAX), >> + NULL >> +}; >> + >> +static const struct hwmon_ops sbrmi_hwmon_ops = { >> + .is_visible = sbrmi_is_visible, >> + .read = sbrmi_read, >> + .write = sbrmi_write, >> +}; >> + >> +static const struct hwmon_chip_info sbrmi_chip_info = { >> + .ops = &sbrmi_hwmon_ops, >> + .info = sbrmi_info, >> +}; >> + >> +static int sbrmi_probe(struct i2c_client *client, >> + const struct i2c_device_id *id) { >> + struct device *dev = &client->dev; >> + struct device *hwmon_dev; >> + struct sbrmi_data *data; >> + >> + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { >> + dev_err(&client->dev, "adapter does not support true >> + I2C\n"); > > Why would that matter? It only uses SMBus functions. > [naveenk:] yes, will remove this. > >> + return -ENODEV; >> + } >> + >> + data = devm_kzalloc(dev, sizeof(struct sbrmi_data), GFP_KERNEL); >> + if (!data) >> + return -ENOMEM; >> + >> + data->client = client; >> + mutex_init(&data->lock); >> + >> + hwmon_dev = devm_hwmon_device_register_with_info(dev, >> + client->name, data, >> + >> + &sbrmi_chip_info, NULL); >> + >> + return PTR_ERR_OR_ZERO(hwmon_dev); } >> + >> +static const struct i2c_device_id sbrmi_id[] = { >> + {"sbrmi", 0}, >> + {} >> +}; >> +MODULE_DEVICE_TABLE(i2c, sbrmi_id); >> + >> +static const struct of_device_id __maybe_unused sbrmi_of_match[] = { >> + { >> + .compatible = "amd,sbrmi", >> + }, >> + { }, >> +}; >> +MODULE_DEVICE_TABLE(of, sbrmi_of_match); >> + >> +static struct i2c_driver sbrmi_driver = { >> + .class = I2C_CLASS_HWMON, >> + .driver = { >> + .name = "sbrmi", >> + .of_match_table = of_match_ptr(sbrmi_of_match), >> + }, >> + .probe = sbrmi_probe, >> + .id_table = sbrmi_id, >> +}; >> + >> +module_i2c_driver(sbrmi_driver); >> + >> +MODULE_AUTHOR("Akshay Gupta <akshay.gupta@amd.com>"); >> +MODULE_DESCRIPTION("Hwmon driver for AMD SB-RMI emulated sensor"); >> +MODULE_LICENSE("GPL"); > [naveenk:] Thank you for your comments, we will address your comments and submit v2 soon. >> > [naveenk:] > Regards, > Naveenk >
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 87624902ea80..d1813ea8382c 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -1551,6 +1551,16 @@ config SENSORS_SBTSI This driver can also be built as a module. If so, the module will be called sbtsi_temp. +config SENSORS_SBRMI + tristate "Emulated SB-RMI sensor" + depends on I2C + help + If you say yes here you get support for emulated RMI + sensors on AMD SoCs with APML interface connected to a BMC device. + + This driver can also be built as a module. If so, the module will + be called sbrmi. + config SENSORS_SHT15 tristate "Sensiron humidity and temperature sensors. SHT15 and compat." depends on GPIOLIB || COMPILE_TEST diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index 59e78bc212cf..8031acf58936 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -164,6 +164,7 @@ obj-$(CONFIG_SENSORS_PWM_FAN) += pwm-fan.o obj-$(CONFIG_SENSORS_RASPBERRYPI_HWMON) += raspberrypi-hwmon.o obj-$(CONFIG_SENSORS_S3C) += s3c-hwmon.o obj-$(CONFIG_SENSORS_SBTSI) += sbtsi_temp.o +obj-$(CONFIG_SENSORS_SBRMI) += sbrmi.o obj-$(CONFIG_SENSORS_SCH56XX_COMMON)+= sch56xx-common.o obj-$(CONFIG_SENSORS_SCH5627) += sch5627.o obj-$(CONFIG_SENSORS_SCH5636) += sch5636.o diff --git a/drivers/hwmon/sbrmi.c b/drivers/hwmon/sbrmi.c new file mode 100644 index 000000000000..c35829513459 --- /dev/null +++ b/drivers/hwmon/sbrmi.c @@ -0,0 +1,394 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * sbrmi.c - hwmon driver for a SB-RMI mailbox + * compliant AMD SoC device. + * + * Copyright (C) 2020-2021 Advanced Micro Devices, Inc. + */ + +#include <linux/err.h> +#include <linux/hwmon.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <asm-generic/ioctl.h> +#include <linux/delay.h> + +/* Do not allow setting negative power limit */ +#define SBRMI_PWR_MIN 0 +/* Mask for Status Register bit[1] */ +#define SW_ALERT_MASK 0x2 + +/* Software Interrupt for triggering */ +#define START_CMD 0x80 +#define TRIGGER_MAILBOX 0x01 + +/* + * SB-RMI supports soft mailbox service request to MP1 (power management + * firmware) through SBRMI inbound/outbound message registers. + * SB-RMI message IDs + */ +enum sbrmi_msg_id { + SBRMI_READ_PKG_PWR_CONSUMPTION = 0x1, + SBRMI_WRITE_PKG_PWR_LIMIT, + SBRMI_READ_PKG_PWR_LIMIT, + SBRMI_READ_PKG_MAX_PWR_LIMIT, +}; + +/* SB-RMI registers */ +enum sbrmi_reg { + SBRMI_CTRL = 0x01, + SBRMI_STATUS, + SBRMI_OUTBNDMSG0 = 0x30, + SBRMI_OUTBNDMSG1, + SBRMI_OUTBNDMSG2, + SBRMI_OUTBNDMSG3, + SBRMI_OUTBNDMSG4, + SBRMI_OUTBNDMSG5, + SBRMI_OUTBNDMSG6, + SBRMI_OUTBNDMSG7, + SBRMI_INBNDMSG0, + SBRMI_INBNDMSG1, + SBRMI_INBNDMSG2, + SBRMI_INBNDMSG3, + SBRMI_INBNDMSG4, + SBRMI_INBNDMSG5, + SBRMI_INBNDMSG6, + SBRMI_INBNDMSG7, + SBRMI_SW_INTERRUPT, +}; + +/* + * Each client has this additional data + */ +struct sbrmi_data { + struct i2c_client *client; + struct mutex lock; +}; + +/* Mailbox message data format */ +union mailbox_word { + u8 bytes[4]; + u32 value; +}; + +struct sbrmi_mailbox_msg { + u8 cmd; + bool read; + union mailbox_word data_in; + union mailbox_word data_out; +}; + +static int print_mailbox_error(struct sbrmi_data *data) +{ + int status; + + /* Mailbox error code will be written by Firmware in + * SBRMI::OutBndMsg_inst7 (SBRMI_x37) + */ + status = i2c_smbus_read_byte_data(data->client, SBRMI_OUTBNDMSG7); + if (status < 0) { + pr_err("SMBUS translation failed\n"); + return status; + } + + switch (status) { + case 0x0: /* Success */ + break; + case 0x1: + pr_err("Mailbox message command is aborted\n"); + break; + case 0x2: + pr_err("Unknown mailbox message\n"); + break; + case 0x3: + pr_err("Invalid core is specified in mailbox message parameters\n"); + break; + default: + pr_err("Unknown Error\n"); + } + + return status; +} + +static int sbrmi_enable_alert(struct sbrmi_data *data) +{ + int ctrl; + + /* Enable the SB-RMI Software alert status + * by writing 0 to bit 4 of Control register(0x1) + */ + ctrl = i2c_smbus_read_byte_data(data->client, SBRMI_CTRL); + if (ctrl < 0) + return ctrl; + + if (ctrl & 0x10) { + ctrl &= ~0x10; + return i2c_smbus_write_byte_data(data->client, + SBRMI_CTRL, ctrl); + } + + return 0; +} + +static int rmi_mailbox_xfer(struct sbrmi_data *data, + struct sbrmi_mailbox_msg *msg) +{ + union mailbox_word output, input; + int i, err = 0, retry = 10; + int sw_status; + + mutex_lock(&data->lock); + + err = sbrmi_enable_alert(data); + if (err < 0) + goto exit_unlock; + + /* Indicate firmware a command is to be serviced */ + err = i2c_smbus_write_byte_data(data->client, + SBRMI_INBNDMSG7, START_CMD); + if (err < 0) + goto exit_unlock; + + /* Write the command to SBRMI::InBndMsg_inst0 */ + err = i2c_smbus_write_byte_data(data->client, + SBRMI_INBNDMSG0, msg->cmd); + if (err < 0) + goto exit_mod; + + /* + * For both read and write the initiator (BMC) writes + * Command Data In[31:0] to SBRMI::InBndMsg_inst[4:1] + * SBRMI_x3C(MSB):SBRMI_x39(LSB) + */ + input = msg->data_in; + for (i = 0; i < 3; i++) { + err = i2c_smbus_write_byte_data(data->client, + (SBRMI_INBNDMSG1 + i), + input.bytes[i]); + if (err < 0) + goto exit_mod; + } + + /* + * Write 0x01 to SBRMI::SoftwareInterrupt to notify firmware to + * perform the requested read or write command + */ + err = i2c_smbus_write_byte_data(data->client, + SBRMI_SW_INTERRUPT, TRIGGER_MAILBOX); + if (err < 0) + goto exit_mod; + + /* + * Firmware will write SBRMI::Status[SwAlertSts]=1 to generate + * an ALERT (if enabled) to initiator (BMC) to indicate completion + * of the requested command + */ + do { + sw_status = i2c_smbus_read_byte_data(data->client, + SBRMI_STATUS); + if (sw_status < 0) { + err = sw_status; + goto exit_mod; + } + if (sw_status & SW_ALERT_MASK) + break; + usleep_range(50, 100); + } while (retry--); + + if (retry < 0) { + pr_err("Firmware fail to indicate command colmpletion\n"); + err = -1; + goto exit_mod; + } + + /* + * For a read operation, the initiator (BMC) reads the firmware response + * Command Data Out[31:0] from SBRMI::OutBndMsg_inst[4:1] + * {SBRMI_x34(MSB):SBRMI_x31(LSB)}. + */ + if (msg->read) { + for (i = 0; i < 4; i++) { + output.bytes[i] = i2c_smbus_read_byte_data(data->client, + (SBRMI_OUTBNDMSG1 + i)); + if (output.bytes[i] < 0) { + err = output.bytes[i]; + goto exit_mod; + } + } + } + msg->data_out = output; + + /* + * BMC must write 1'b1 to SBRMI::Status[SwAlertSts] to clear the + * ALERT to initiator + */ + err = i2c_smbus_write_byte_data(data->client, SBRMI_STATUS, + (sw_status | SW_ALERT_MASK)); + +exit_mod: + if (err < 0) + pr_err("SMBUS translation failed\n"); + else + err = print_mailbox_error(data); +exit_unlock: + mutex_unlock(&data->lock); + return err; +} + +static int sbrmi_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + struct sbrmi_data *data = dev_get_drvdata(dev); + struct sbrmi_mailbox_msg msg = { 0 }; + int ret; + + if (type != hwmon_power) + return -EINVAL; + + msg.read = true; + switch (attr) { + case hwmon_power_input: + msg.cmd = SBRMI_READ_PKG_PWR_CONSUMPTION; + ret = rmi_mailbox_xfer(data, &msg); + break; + case hwmon_power_cap: + msg.cmd = SBRMI_READ_PKG_PWR_LIMIT; + ret = rmi_mailbox_xfer(data, &msg); + break; + case hwmon_power_cap_max: + msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; + ret = rmi_mailbox_xfer(data, &msg); + break; + default: + return -EINVAL; + } + /* + * hwmon power attributes are in microWatt + */ + *val = (long)msg.data_out.value * 1000; + return ret; +} + +static int sbrmi_write(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long val) +{ + struct sbrmi_data *data = dev_get_drvdata(dev); + struct sbrmi_mailbox_msg msg = { 0 }; + + if (type != hwmon_power && attr != hwmon_power_cap) + return -EINVAL; + /* + * hwmon power attributes are in microWatt + * mailbox read/write is in mWatt + */ + val /= 1000; + + msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; + msg.data_in.value = 0; + msg.read = true; + rmi_mailbox_xfer(data, &msg); + + val = clamp_val(val, SBRMI_PWR_MIN, msg.data_out.value); + + msg.cmd = SBRMI_WRITE_PKG_PWR_LIMIT; + msg.data_in.value = val; + msg.read = false; + + return rmi_mailbox_xfer(data, &msg); +} + +static umode_t sbrmi_is_visible(const void *data, + enum hwmon_sensor_types type, + u32 attr, int channel) +{ + switch (type) { + case hwmon_power: + switch (attr) { + case hwmon_power_input: + case hwmon_power_cap_max: + return 0444; + case hwmon_power_cap: + return 0644; + } + break; + default: + break; + } + return 0; +} + +static const struct hwmon_channel_info *sbrmi_info[] = { + HWMON_CHANNEL_INFO(power, + HWMON_P_INPUT | HWMON_P_CAP | HWMON_P_CAP_MAX), + NULL +}; + +static const struct hwmon_ops sbrmi_hwmon_ops = { + .is_visible = sbrmi_is_visible, + .read = sbrmi_read, + .write = sbrmi_write, +}; + +static const struct hwmon_chip_info sbrmi_chip_info = { + .ops = &sbrmi_hwmon_ops, + .info = sbrmi_info, +}; + +static int sbrmi_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device *dev = &client->dev; + struct device *hwmon_dev; + struct sbrmi_data *data; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { + dev_err(&client->dev, "adapter does not support true I2C\n"); + return -ENODEV; + } + + data = devm_kzalloc(dev, sizeof(struct sbrmi_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->client = client; + mutex_init(&data->lock); + + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data, + &sbrmi_chip_info, NULL); + + return PTR_ERR_OR_ZERO(hwmon_dev); +} + +static const struct i2c_device_id sbrmi_id[] = { + {"sbrmi", 0}, + {} +}; +MODULE_DEVICE_TABLE(i2c, sbrmi_id); + +static const struct of_device_id __maybe_unused sbrmi_of_match[] = { + { + .compatible = "amd,sbrmi", + }, + { }, +}; +MODULE_DEVICE_TABLE(of, sbrmi_of_match); + +static struct i2c_driver sbrmi_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = "sbrmi", + .of_match_table = of_match_ptr(sbrmi_of_match), + }, + .probe = sbrmi_probe, + .id_table = sbrmi_id, +}; + +module_i2c_driver(sbrmi_driver); + +MODULE_AUTHOR("Akshay Gupta <akshay.gupta@amd.com>"); +MODULE_DESCRIPTION("Hwmon driver for AMD SB-RMI emulated sensor"); +MODULE_LICENSE("GPL");