| Message ID | 20200909203059.23427-3-eajames@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | input: misc: Add IBM Operation Panel driver | expand |
On Wed, Sep 09, 2020 at 03:30:56PM -0500, Eddie James wrote: > Add a driver to get the button events from the panel and provide > them to userspace with the input subsystem. The panel is > connected with I2C and controls the bus, so the driver registers > as an I2C slave device. > > Signed-off-by: Eddie James <eajames@linux.ibm.com> > Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com> # I2C slave parts
Hi Eddie, On Wed, Sep 09, 2020 at 03:30:56PM -0500, Eddie James wrote: > Add a driver to get the button events from the panel and provide > them to userspace with the input subsystem. The panel is > connected with I2C and controls the bus, so the driver registers > as an I2C slave device. > > Signed-off-by: Eddie James <eajames@linux.ibm.com> > Reviewed-by: Joel Stanley <joel@jms.id.au> > --- > MAINTAINERS | 1 + > drivers/input/misc/Kconfig | 18 ++++ > drivers/input/misc/Makefile | 1 + > drivers/input/misc/ibm-panel.c | 189 +++++++++++++++++++++++++++++++++ > 4 files changed, 209 insertions(+) > create mode 100644 drivers/input/misc/ibm-panel.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 28408d29d873..5429da957a1a 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -8351,6 +8351,7 @@ M: Eddie James <eajames@linux.ibm.com> > L: linux-input@vger.kernel.org > S: Maintained > F: Documentation/devicetree/bindings/input/ibm,op-panel.yaml > +F: drivers/input/misc/ibm-panel.c > > IBM Power 842 compression accelerator > M: Haren Myneni <haren@us.ibm.com> > diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig > index 362e8a01980c..65ab1ce7b259 100644 > --- a/drivers/input/misc/Kconfig > +++ b/drivers/input/misc/Kconfig > @@ -708,6 +708,24 @@ config INPUT_ADXL34X_SPI > To compile this driver as a module, choose M here: the > module will be called adxl34x-spi. > > +config INPUT_IBM_PANEL > + tristate "IBM Operation Panel driver" > + depends on I2C_SLAVE || COMPILE_TEST > + help > + Say Y here if you have an IBM Operation Panel connected to your system > + over I2C. The panel is typically connected only to a system's service > + processor (BMC). > + > + If unsure, say N. > + > + The Operation Panel is a controller with some buttons and an LCD > + display that allows someone with physical access to the system to > + perform various administrative tasks. This driver only supports the part > + of the controller that sends commands to the system. > + > + To compile this driver as a module, choose M here: the module will be > + called ibm-panel. > + > config INPUT_IMS_PCU > tristate "IMS Passenger Control Unit driver" > depends on USB > diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile > index a48e5f2d859d..7e9edf0a142b 100644 > --- a/drivers/input/misc/Makefile > +++ b/drivers/input/misc/Makefile > @@ -38,6 +38,7 @@ obj-$(CONFIG_INPUT_GPIO_DECODER) += gpio_decoder.o > obj-$(CONFIG_INPUT_GPIO_VIBRA) += gpio-vibra.o > obj-$(CONFIG_INPUT_HISI_POWERKEY) += hisi_powerkey.o > obj-$(CONFIG_HP_SDC_RTC) += hp_sdc_rtc.o > +obj-$(CONFIG_INPUT_IBM_PANEL) += ibm-panel.o > obj-$(CONFIG_INPUT_IMS_PCU) += ims-pcu.o > obj-$(CONFIG_INPUT_IQS269A) += iqs269a.o > obj-$(CONFIG_INPUT_IXP4XX_BEEPER) += ixp4xx-beeper.o > diff --git a/drivers/input/misc/ibm-panel.c b/drivers/input/misc/ibm-panel.c > new file mode 100644 > index 000000000000..7329f4641636 > --- /dev/null > +++ b/drivers/input/misc/ibm-panel.c > @@ -0,0 +1,189 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Copyright (C) IBM Corporation 2020 > + */ > + > +#include <linux/i2c.h> > +#include <linux/init.h> > +#include <linux/input.h> > +#include <linux/kernel.h> > +#include <linux/limits.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/spinlock.h> > + > +#define DEVICE_NAME "ibm-panel" > + > +struct ibm_panel { > + u8 idx; > + u8 command[11]; > + spinlock_t lock; /* protects writes to idx and command */ > + struct input_dev *input; > +}; > + > +static void ibm_panel_process_command(struct ibm_panel *panel) > +{ > + u8 i; > + u8 chksum; > + u16 sum = 0; > + int pressed; > + int released; > + > + if (panel->command[0] != 0xff && panel->command[1] != 0xf0) { > + dev_dbg(&panel->input->dev, "command invalid\n"); > + return; > + } > + > + for (i = 0; i < sizeof(panel->command) - 1; ++i) { > + sum += panel->command[i]; > + if (sum & 0xff00) { > + sum &= 0xff; > + sum++; > + } > + } > + > + chksum = sum & 0xff; > + chksum = ~chksum; > + chksum++; Maybe move checksum calculation into a separate function? > + > + if (chksum != panel->command[sizeof(panel->command) - 1]) { > + dev_dbg(&panel->input->dev, "command failed checksum\n"); > + return; > + } > + > + released = panel->command[2] & 0x80; > + pressed = released ? 0 : 1; pressed = !(panel->command[2] & BIT(7)); or "pressed = !released;" if you want to keep both. > + > + switch (panel->command[2] & 0xf) { > + case 0: > + input_report_key(panel->input, BTN_NORTH, pressed); > + break; > + case 1: > + input_report_key(panel->input, BTN_SOUTH, pressed); > + break; > + case 2: > + input_report_key(panel->input, BTN_SELECT, pressed); > + break; > + default: > + dev_dbg(&panel->input->dev, "unknown command %u\n", > + panel->command[2] & 0xf); > + return; > + } > + > + input_sync(panel->input); > +} > + > +static int ibm_panel_i2c_slave_cb(struct i2c_client *client, > + enum i2c_slave_event event, u8 *val) > +{ > + unsigned long flags; > + struct ibm_panel *panel = i2c_get_clientdata(client); > + > + dev_dbg(&panel->input->dev, "event: %u data: %02x\n", event, *val); > + > + spin_lock_irqsave(&panel->lock, flags); > + > + switch (event) { > + case I2C_SLAVE_STOP: > + if (panel->idx == sizeof(panel->command)) > + ibm_panel_process_command(panel); > + else > + dev_dbg(&panel->input->dev, > + "command incorrect size %u\n", panel->idx); > + fallthrough; > + case I2C_SLAVE_WRITE_REQUESTED: > + panel->idx = 0; > + break; > + case I2C_SLAVE_WRITE_RECEIVED: > + if (panel->idx < sizeof(panel->command)) > + panel->command[panel->idx++] = *val; > + else > + /* > + * The command is too long and therefore invalid, so set the index > + * to it's largest possible value. When a STOP is finally received, > + * the command will be rejected upon processing. > + */ > + panel->idx = U8_MAX; > + break; > + case I2C_SLAVE_READ_REQUESTED: > + case I2C_SLAVE_READ_PROCESSED: > + *val = 0xff; > + break; > + default: > + break; > + } > + > + spin_unlock_irqrestore(&panel->lock, flags); > + > + return 0; > +} > + > +static int ibm_panel_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + int rc; > + struct ibm_panel *panel = devm_kzalloc(&client->dev, sizeof(*panel), > + GFP_KERNEL); > + > + if (!panel) > + return -ENOMEM; > + > + panel->input = devm_input_allocate_device(&client->dev); > + if (!panel->input) > + return -ENOMEM; > + > + panel->input->name = client->name; > + panel->input->id.bustype = BUS_I2C; > + input_set_capability(panel->input, EV_KEY, BTN_NORTH); > + input_set_capability(panel->input, EV_KEY, BTN_SOUTH); > + input_set_capability(panel->input, EV_KEY, BTN_SELECT); North/South/Select are gamepad buttons, not general purpose ones. I think you should not hard-code keymap in the driver, but rather use device property to specify keymap that makes sense for the particular board's application. > + > + rc = input_register_device(panel->input); > + if (rc) { > + dev_err(&client->dev, "Failed to register input device: %d\n", > + rc); > + return rc; > + } > + > + spin_lock_init(&panel->lock); > + > + i2c_set_clientdata(client, panel); > + rc = i2c_slave_register(client, ibm_panel_i2c_slave_cb); > + if (rc) { > + input_unregister_device(panel->input); You are using devm, there is no need to manually unregister input device. > + return rc; > + } > + > + return 0; > +} > + > +static int ibm_panel_remove(struct i2c_client *client) > +{ > + int rc; > + struct ibm_panel *panel = i2c_get_clientdata(client); > + > + rc = i2c_slave_unregister(client); > + > + input_unregister_device(panel->input); This is not needed. > + > + return rc; The remove operation is not reversible, so there is no need to return error here. Just log en error if i2c_slave_unregister() fails if you want, and return 0. > +} > + > +static const struct of_device_id ibm_panel_match[] = { > + { .compatible = "ibm,op-panel" }, > + { } > +}; > + > +static struct i2c_driver ibm_panel_driver = { > + .driver = { > + .name = DEVICE_NAME, > + .of_match_table = ibm_panel_match, > + }, > + .probe = ibm_panel_probe, > + .remove = ibm_panel_remove, > +}; > +module_i2c_driver(ibm_panel_driver); > + > +MODULE_AUTHOR("Eddie James <eajames@linux.ibm.com>"); > +MODULE_DESCRIPTION("IBM Operation Panel Driver"); > +MODULE_LICENSE("GPL"); > -- > 2.26.2 > Thanks.
diff --git a/MAINTAINERS b/MAINTAINERS index 28408d29d873..5429da957a1a 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8351,6 +8351,7 @@ M: Eddie James <eajames@linux.ibm.com> L: linux-input@vger.kernel.org S: Maintained F: Documentation/devicetree/bindings/input/ibm,op-panel.yaml +F: drivers/input/misc/ibm-panel.c IBM Power 842 compression accelerator M: Haren Myneni <haren@us.ibm.com> diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig index 362e8a01980c..65ab1ce7b259 100644 --- a/drivers/input/misc/Kconfig +++ b/drivers/input/misc/Kconfig @@ -708,6 +708,24 @@ config INPUT_ADXL34X_SPI To compile this driver as a module, choose M here: the module will be called adxl34x-spi. +config INPUT_IBM_PANEL + tristate "IBM Operation Panel driver" + depends on I2C_SLAVE || COMPILE_TEST + help + Say Y here if you have an IBM Operation Panel connected to your system + over I2C. The panel is typically connected only to a system's service + processor (BMC). + + If unsure, say N. + + The Operation Panel is a controller with some buttons and an LCD + display that allows someone with physical access to the system to + perform various administrative tasks. This driver only supports the part + of the controller that sends commands to the system. + + To compile this driver as a module, choose M here: the module will be + called ibm-panel. + config INPUT_IMS_PCU tristate "IMS Passenger Control Unit driver" depends on USB diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile index a48e5f2d859d..7e9edf0a142b 100644 --- a/drivers/input/misc/Makefile +++ b/drivers/input/misc/Makefile @@ -38,6 +38,7 @@ obj-$(CONFIG_INPUT_GPIO_DECODER) += gpio_decoder.o obj-$(CONFIG_INPUT_GPIO_VIBRA) += gpio-vibra.o obj-$(CONFIG_INPUT_HISI_POWERKEY) += hisi_powerkey.o obj-$(CONFIG_HP_SDC_RTC) += hp_sdc_rtc.o +obj-$(CONFIG_INPUT_IBM_PANEL) += ibm-panel.o obj-$(CONFIG_INPUT_IMS_PCU) += ims-pcu.o obj-$(CONFIG_INPUT_IQS269A) += iqs269a.o obj-$(CONFIG_INPUT_IXP4XX_BEEPER) += ixp4xx-beeper.o diff --git a/drivers/input/misc/ibm-panel.c b/drivers/input/misc/ibm-panel.c new file mode 100644 index 000000000000..7329f4641636 --- /dev/null +++ b/drivers/input/misc/ibm-panel.c @@ -0,0 +1,189 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) IBM Corporation 2020 + */ + +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/input.h> +#include <linux/kernel.h> +#include <linux/limits.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/spinlock.h> + +#define DEVICE_NAME "ibm-panel" + +struct ibm_panel { + u8 idx; + u8 command[11]; + spinlock_t lock; /* protects writes to idx and command */ + struct input_dev *input; +}; + +static void ibm_panel_process_command(struct ibm_panel *panel) +{ + u8 i; + u8 chksum; + u16 sum = 0; + int pressed; + int released; + + if (panel->command[0] != 0xff && panel->command[1] != 0xf0) { + dev_dbg(&panel->input->dev, "command invalid\n"); + return; + } + + for (i = 0; i < sizeof(panel->command) - 1; ++i) { + sum += panel->command[i]; + if (sum & 0xff00) { + sum &= 0xff; + sum++; + } + } + + chksum = sum & 0xff; + chksum = ~chksum; + chksum++; + + if (chksum != panel->command[sizeof(panel->command) - 1]) { + dev_dbg(&panel->input->dev, "command failed checksum\n"); + return; + } + + released = panel->command[2] & 0x80; + pressed = released ? 0 : 1; + + switch (panel->command[2] & 0xf) { + case 0: + input_report_key(panel->input, BTN_NORTH, pressed); + break; + case 1: + input_report_key(panel->input, BTN_SOUTH, pressed); + break; + case 2: + input_report_key(panel->input, BTN_SELECT, pressed); + break; + default: + dev_dbg(&panel->input->dev, "unknown command %u\n", + panel->command[2] & 0xf); + return; + } + + input_sync(panel->input); +} + +static int ibm_panel_i2c_slave_cb(struct i2c_client *client, + enum i2c_slave_event event, u8 *val) +{ + unsigned long flags; + struct ibm_panel *panel = i2c_get_clientdata(client); + + dev_dbg(&panel->input->dev, "event: %u data: %02x\n", event, *val); + + spin_lock_irqsave(&panel->lock, flags); + + switch (event) { + case I2C_SLAVE_STOP: + if (panel->idx == sizeof(panel->command)) + ibm_panel_process_command(panel); + else + dev_dbg(&panel->input->dev, + "command incorrect size %u\n", panel->idx); + fallthrough; + case I2C_SLAVE_WRITE_REQUESTED: + panel->idx = 0; + break; + case I2C_SLAVE_WRITE_RECEIVED: + if (panel->idx < sizeof(panel->command)) + panel->command[panel->idx++] = *val; + else + /* + * The command is too long and therefore invalid, so set the index + * to it's largest possible value. When a STOP is finally received, + * the command will be rejected upon processing. + */ + panel->idx = U8_MAX; + break; + case I2C_SLAVE_READ_REQUESTED: + case I2C_SLAVE_READ_PROCESSED: + *val = 0xff; + break; + default: + break; + } + + spin_unlock_irqrestore(&panel->lock, flags); + + return 0; +} + +static int ibm_panel_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + int rc; + struct ibm_panel *panel = devm_kzalloc(&client->dev, sizeof(*panel), + GFP_KERNEL); + + if (!panel) + return -ENOMEM; + + panel->input = devm_input_allocate_device(&client->dev); + if (!panel->input) + return -ENOMEM; + + panel->input->name = client->name; + panel->input->id.bustype = BUS_I2C; + input_set_capability(panel->input, EV_KEY, BTN_NORTH); + input_set_capability(panel->input, EV_KEY, BTN_SOUTH); + input_set_capability(panel->input, EV_KEY, BTN_SELECT); + + rc = input_register_device(panel->input); + if (rc) { + dev_err(&client->dev, "Failed to register input device: %d\n", + rc); + return rc; + } + + spin_lock_init(&panel->lock); + + i2c_set_clientdata(client, panel); + rc = i2c_slave_register(client, ibm_panel_i2c_slave_cb); + if (rc) { + input_unregister_device(panel->input); + return rc; + } + + return 0; +} + +static int ibm_panel_remove(struct i2c_client *client) +{ + int rc; + struct ibm_panel *panel = i2c_get_clientdata(client); + + rc = i2c_slave_unregister(client); + + input_unregister_device(panel->input); + + return rc; +} + +static const struct of_device_id ibm_panel_match[] = { + { .compatible = "ibm,op-panel" }, + { } +}; + +static struct i2c_driver ibm_panel_driver = { + .driver = { + .name = DEVICE_NAME, + .of_match_table = ibm_panel_match, + }, + .probe = ibm_panel_probe, + .remove = ibm_panel_remove, +}; +module_i2c_driver(ibm_panel_driver); + +MODULE_AUTHOR("Eddie James <eajames@linux.ibm.com>"); +MODULE_DESCRIPTION("IBM Operation Panel Driver"); +MODULE_LICENSE("GPL");