| Message ID | 20190123183325.92946-4-ncrews@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | platform/chrome: rtc: Add support for Wilco EC | expand |
Hi Nick, Missatge de Nick Crews <ncrews@chromium.org> del dia dc., 23 de gen. 2019 a les 19:38: > > From: Duncan Laurie <dlaurie@google.com> > > Add a debugfs attribute that allows sending raw commands to the EC. > This is useful for development and debug but should not be enabled > in a production environment. > > Turn the keyboard global mic mute led on > > echo 00 f2 01 76 06 00 00 01 01 > /sys/kernel/debug/wilco_ec/raw > Turn the keyboard global mic mute led off > > echo 00 f2 01 76 06 00 00 01 00 > /sys/kernel/debug/wilco_ec/raw That won't be a real example, right? Would be better remove it? > Get the EC firmware build date > First send the request command > > echo 00 f0 38 00 03 00 > raw > Then read the result. "12/21/18" is in the middle of the response > > cat raw > 00 31 32 2f 32 31 2f 31 38 00 00 0f 01 00 01 00 .12/21/18....... > > Signed-off-by: Duncan Laurie <dlaurie@google.com> > Signed-off-by: Nick Crews <ncrews@chromium.org> > --- > > Changes in v4: > - Change debugfs driver to be a separate module > - Change me email to @chromium.org from @google.com > - Change CONFIG_WILCO_EC_SYSFS_RAW to > CONFIG_WILCO_EC_DEBUGFS > > Changes in v3: > - Move the attribute to the debugfs system > - Move the implementation to debugfs.c > - Improve the raw hex parsing > - Encapsulate global variables in one object > - Add safety check when passing less than 3 bytes > - Move documentation to debugfs-wilco-ec > > Changes in v2: > - Add sysfs documentation > - rm duplicate EC_MAILBOX_DATA_SIZE defs > - Make docstrings follow kernel style > - Fix tags in commit msg > - Move Kconfig to subdirectory > - Reading raw now includes ASCII translation > > Documentation/ABI/testing/debugfs-wilco-ec | 23 +++ > drivers/platform/chrome/wilco_ec/Kconfig | 9 + > drivers/platform/chrome/wilco_ec/Makefile | 2 + > drivers/platform/chrome/wilco_ec/core.c | 20 ++ > drivers/platform/chrome/wilco_ec/debugfs.c | 226 +++++++++++++++++++++ > 5 files changed, 280 insertions(+) > create mode 100644 Documentation/ABI/testing/debugfs-wilco-ec > create mode 100644 drivers/platform/chrome/wilco_ec/debugfs.c > > diff --git a/Documentation/ABI/testing/debugfs-wilco-ec b/Documentation/ABI/testing/debugfs-wilco-ec > new file mode 100644 > index 000000000000..90bc3fe08dff > --- /dev/null > +++ b/Documentation/ABI/testing/debugfs-wilco-ec > @@ -0,0 +1,23 @@ > +What: /sys/kernel/debug/wilco_ec/raw > +Date: January 2019 > +KernelVersion: 4.19 > +Description: > + Write and read raw mailbox commands to the EC. > + > + For writing: > + Bytes 0-1 indicate the message type: > + 00 F0 = Execute Legacy Command > + 00 F2 = Read/Write NVRAM Property > + Byte 2 provides the command code > + Bytes 3+ consist of the data passed in the request > + > + Example: > + // Request EC info type 3 (EC firmware build date) > + $ echo 00 f0 38 00 03 00 > raw > + // View the result. The decoded ASCII result "12/21/18" is > + // included after the raw hex. > + $ cat raw > + 00 31 32 2f 32 31 2f 31 38 00 38 00 01 00 2f 00 .12/21/18.8... > + > + At least three bytes are required, for the msg type and command, > + with additional bytes optional for additional data. > diff --git a/drivers/platform/chrome/wilco_ec/Kconfig b/drivers/platform/chrome/wilco_ec/Kconfig > index 20945a301ec6..56b871510c4d 100644 > --- a/drivers/platform/chrome/wilco_ec/Kconfig > +++ b/drivers/platform/chrome/wilco_ec/Kconfig > @@ -9,3 +9,12 @@ config WILCO_EC > > To compile this driver as a module, choose M here: the > module will be called wilco_ec. > + > +config WILCO_EC_DEBUGFS > + tristate "Enable raw access to EC via debugfs" > + depends on WILCO_EC > + help > + If you say Y here, you get support for sending raw commands to > + the Wilco EC via debugfs. These commands do not do any byte > + manipulation and allow for testing arbitrary commands. This > + interface is intended for debug only and is disabled by default. > diff --git a/drivers/platform/chrome/wilco_ec/Makefile b/drivers/platform/chrome/wilco_ec/Makefile > index 03b32301dc61..063e7fb4ea17 100644 > --- a/drivers/platform/chrome/wilco_ec/Makefile > +++ b/drivers/platform/chrome/wilco_ec/Makefile > @@ -2,3 +2,5 @@ > > wilco_ec-objs := core.o mailbox.o > obj-$(CONFIG_WILCO_EC) += wilco_ec.o > +wilco_ec_debugfs-objs := debugfs.o > +obj-$(CONFIG_WILCO_EC_DEBUGFS) += wilco_ec_debugfs.o > diff --git a/drivers/platform/chrome/wilco_ec/core.c b/drivers/platform/chrome/wilco_ec/core.c > index 7dcb3bde132a..e036d88b6dd8 100644 > --- a/drivers/platform/chrome/wilco_ec/core.c > +++ b/drivers/platform/chrome/wilco_ec/core.c > @@ -44,6 +44,8 @@ static int wilco_ec_probe(struct platform_device *pdev) > { > struct device *dev = &pdev->dev; > struct wilco_ec_device *ec; > + struct platform_device *child_pdev; > + int ret; > > ec = devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL); > if (!ec) > @@ -71,7 +73,25 @@ static int wilco_ec_probe(struct platform_device *pdev) > cros_ec_lpc_mec_init(ec->io_packet->start, > ec->io_packet->start + EC_MAILBOX_DATA_SIZE); > > + /* > + * Register a debugfs platform device that will get picked up by the > + * debugfs driver. This platform device will get freed when its parent > + * device dev is unregistered. > + */ > + child_pdev = platform_device_register_data(dev, "wilco-ec-debugfs", > + PLATFORM_DEVID_AUTO, > + NULL, 0); > + if (IS_ERR(child_pdev)) { > + dev_err(dev, "Failed to create debugfs platform device\n"); > + ret = PTR_ERR(child_pdev); > + goto destroy_mec; I don't think makes sense destroy the wilco-ec if for some reason the debugfs interface driver fails (unlikely). Your driver should have the same behaviour without depending on the debugfs part ... > + } > + > return 0; > + > +destroy_mec: > + cros_ec_lpc_mec_destroy(); > + return ret; ... and then you can remove this error cleanup for now. > } > > static int wilco_ec_remove(struct platform_device *pdev) > diff --git a/drivers/platform/chrome/wilco_ec/debugfs.c b/drivers/platform/chrome/wilco_ec/debugfs.c > new file mode 100644 > index 000000000000..6c12cd093209 > --- /dev/null > +++ b/drivers/platform/chrome/wilco_ec/debugfs.c > @@ -0,0 +1,226 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * debugfs attributes for Wilco EC > + * > + * Copyright 2019 Google LLC > + * > + * There is only one attribute used for debugging, called raw. > + * You can write a hexadecimal sentence to raw, and that series of bytes > + * will be sent to the EC. Then, you can read the bytes of response > + * by reading from raw. > + */ > + > +#include <linux/ctype.h> > +#include <linux/debugfs.h> > +#include <linux/fs.h> > +#include <linux/module.h> > +#include <linux/platform_data/wilco-ec.h> > +#include <linux/platform_device.h> > + > +#define DRV_NAME "wilco-ec-debugfs" > + > +/* The 256 raw bytes will take up more space when represented as a hex string */ > +#define FORMATTED_BUFFER_SIZE (EC_MAILBOX_DATA_SIZE_EXTENDED * 4) > + > +struct wilco_ec_debugfs { > + struct wilco_ec_device *ec; > + struct dentry *dir; > + size_t response_size; > + u8 raw_data[EC_MAILBOX_DATA_SIZE_EXTENDED]; > + u8 formatted_data[FORMATTED_BUFFER_SIZE]; > +}; > + > +static struct wilco_ec_debugfs *debug_info; > + > +/** > + * parse_hex_sentence() - Convert a ascii hex representation into byte array > + * @in: Input buffer of ascii > + * @isize: Length of input buffer > + * @out: Output buffer > + * @osize: Length of output buffer, e.g. max number of bytes to parse > + * > + * An valid input is a series of ascii hexadecimal numbers, separated by spaces. > + * An example valid input is > + * " 00 f2 0 000076 6 0 ff" > + * > + * If an individual "word" within the hex sentence is longer than MAX_WORD_SIZE, > + * then the sentence is illegal, and parsing will fail. > + * > + * Return: Number of bytes parsed, or negative error code on failure > + */ > +static int parse_hex_sentence(const char *in, int isize, u8 *out, int osize) > +{ > + int n_parsed = 0; > + int word_start = 0; > + int word_end; > + int word_len; > + /* Temp buffer for holding a "word" of chars that represents one byte */ > + const static int MAX_WORD_SIZE = 16; > + char tmp[MAX_WORD_SIZE+1]; spaces around + [my first filter is run checkpatch.pl --strict :) ] > + u8 byte; > + > + while (word_start < isize && n_parsed < osize) { > + /* Find the start of the next word */ > + while (word_start < isize && isspace(in[word_start])) > + word_start++; > + /* reached the end of the input before next word? */ > + if (word_start >= isize) > + break; > + > + /* Find the end of this word */ > + word_end = word_start; > + while (word_end < isize && !isspace(in[word_end])) > + word_end++; > + > + /* Copy to a tmp NULL terminated string */ > + word_len = word_end - word_start; > + if (word_len > MAX_WORD_SIZE) > + return -EINVAL; > + memcpy(tmp, in + word_start, word_len); > + tmp[word_len] = '\0'; > + > + /* > + * Convert from hex string, place in output. If fails to parse, > + * just return -EINVAL because specific error code is only > + * relevant for this one word, returning it would be confusing. > + */ > + if (kstrtou8(tmp, 16, &byte)) > + return -EINVAL; > + out[n_parsed++] = byte; > + > + word_start = word_end; > + } > + return n_parsed; > +} > + > +/* The message type takes up two bytes and the command takes a byte */ > +#define CMDS_AND_DATA_SIZE ((EC_MAILBOX_DATA_SIZE) + 3) > + > +static ssize_t raw_write(struct file *file, const char __user *user_buf, > + size_t count, loff_t *ppos) > +{ > + char *buf = debug_info->formatted_data; > + struct wilco_ec_message msg; > + u8 request_data[CMDS_AND_DATA_SIZE]; > + ssize_t kcount; > + int ret; > + > + if (count > FORMATTED_BUFFER_SIZE) > + return -EINVAL; > + > + kcount = simple_write_to_buffer(buf, FORMATTED_BUFFER_SIZE, ppos, > + user_buf, count); > + if (kcount < 0) > + return kcount; > + > + ret = parse_hex_sentence(buf, kcount, request_data, CMDS_AND_DATA_SIZE); > + if (ret < 0) > + return ret; > + /* Need at least three bytes for type and command */ > + if (ret < 3) > + return -EINVAL; > + > + /* Clear response data buffer */ > + memset(debug_info->raw_data, '\0', EC_MAILBOX_DATA_SIZE_EXTENDED); > + > + msg.type = request_data[0] << 8 | request_data[1]; > + msg.flags = WILCO_EC_FLAG_RAW; > + msg.command = request_data[2]; > + msg.request_data = ret > 3 ? request_data + 3 : NULL; > + msg.request_size = ret - 3; > + msg.response_data = debug_info->raw_data; > + msg.response_size = EC_MAILBOX_DATA_SIZE; > + > + /* Telemetry commands use extended response data */ > + if (msg.type == WILCO_EC_MSG_TELEMETRY) { > + msg.flags |= WILCO_EC_FLAG_EXTENDED_DATA; > + msg.response_size = EC_MAILBOX_DATA_SIZE_EXTENDED; > + } > + > + ret = wilco_ec_mailbox(debug_info->ec, &msg); > + if (ret < 0) > + return ret; > + debug_info->response_size = ret; > + > + return count; > +} > + > +/** > + * wilco_ec_raw_show() - Show result from previous call to raw_store() If you want to have the function documentation (see comment below) s/wilco_ec_raw_show/wilco_ec_raw_read/ and s/raw_store/wilco_ec_raw_write/ > + * @dev: Device representing the EC > + * @attr: The attribute in question > + * @buf: Output buffer to be filled > + * Note that the documentation doesn't match with current function. You can either, fix the documentation and also document wilco_ec_raw_write or just remove that documentation. For me it is clear what read/write means, It might make sense for the examples, but it is also documented in the debugfs-wilco-ec file (sometimes duplicating the info is a source of mismatches). > + * Example usage: > + * // Call raw_store(), read EC info type 3 (EC firmware build date) > + * # echo 00 f0 38 00 03 00 > raw > + * // Call this function, view the result. The decoded ASCII result > + * // "12/21/18" is included after the raw hex. > + * # cat raw > + * 00 31 32 2f 32 31 2f 31 38 00 38 00 01 00 2f 00 .12/21/18.8.../. > + * > + * Return: Number of bytes written to output, negative error code on failure > + */ > +static ssize_t raw_read(struct file *file, char __user *user_buf, size_t count, > + loff_t *ppos) s/raw_read/wilco_ec_raw_read/ > +{ > + int fmt_len = 0; > + > + if (debug_info->response_size) { > + fmt_len = hex_dump_to_buffer(debug_info->raw_data, > + debug_info->response_size, > + 16, 1, debug_info->formatted_data, > + FORMATTED_BUFFER_SIZE, true); > + /* Only return response the first time it is read */ > + debug_info->response_size = 0; > + } > + > + return simple_read_from_buffer(user_buf, count, ppos, > + debug_info->formatted_data, fmt_len); > +} > + > +static const struct file_operations fops_raw = { > + .owner = THIS_MODULE, > + .read = raw_read, s/raw_read/wilco_ec_raw_read/ > + .write = raw_write, s/raw_write/wilco_ec_raw_write/ > + .llseek = no_llseek, > +}; > + > +static int wilco_ec_debugfs_probe(struct platform_device *pdev) > +{ > + /* > + * Ignore all errors, if there's a problem then we're already on fire: > + * www.mail-archive.com/linux-kernel@vger.kernel.org/msg1906997.html > + */ I'd prefer if you remove this comment, as is not really true (see below) and likely this will end on a broken link in the future. > + struct wilco_ec_device *ec = dev_get_drvdata(pdev->dev.parent); > + > + debug_info = devm_kzalloc(&pdev->dev, sizeof(*debug_info), GFP_KERNEL); Oh, you should check the return value of devm_kzalloc, which would cause a NULL pointer dereference in a OOM situation. It's only for the debugfs calls that you should not have to check the error. > + debug_info->ec = ec; > + debug_info->dir = debugfs_create_dir("wilco_ec", NULL); > + debugfs_create_file("raw", 0644, debug_info->dir, NULL, &fops_raw); > + > + return 0; > +} > + > +static int wilco_ec_debugfs_remove(struct platform_device *pdev) > +{ > + if (debug_info) It is possible to have debug_info not allocated at this point? I think that now you can remove this check > + debugfs_remove_recursive(debug_info->dir); > + > + return 0; > +} > + > +static struct platform_driver wilco_ec_debugfs_driver = { > + .driver = { > + .name = DRV_NAME, > + }, > + .probe = wilco_ec_debugfs_probe, > + .remove = wilco_ec_debugfs_remove, > +}; > + > +module_platform_driver(wilco_ec_debugfs_driver); > + > +MODULE_ALIAS("platform:" DRV_NAME); > +MODULE_AUTHOR("Nick Crews <ncrews@chromium.org>"); > +MODULE_LICENSE("GPL v2"); > +MODULE_DESCRIPTION("Wilco EC debugfs driver"); > -- > 2.20.1.321.g9e740568ce-goog > After solving these comments I think you can add my Acked-for-chrome-platform-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Thanks, Enric
diff --git a/Documentation/ABI/testing/debugfs-wilco-ec b/Documentation/ABI/testing/debugfs-wilco-ec new file mode 100644 index 000000000000..90bc3fe08dff --- /dev/null +++ b/Documentation/ABI/testing/debugfs-wilco-ec @@ -0,0 +1,23 @@ +What: /sys/kernel/debug/wilco_ec/raw +Date: January 2019 +KernelVersion: 4.19 +Description: + Write and read raw mailbox commands to the EC. + + For writing: + Bytes 0-1 indicate the message type: + 00 F0 = Execute Legacy Command + 00 F2 = Read/Write NVRAM Property + Byte 2 provides the command code + Bytes 3+ consist of the data passed in the request + + Example: + // Request EC info type 3 (EC firmware build date) + $ echo 00 f0 38 00 03 00 > raw + // View the result. The decoded ASCII result "12/21/18" is + // included after the raw hex. + $ cat raw + 00 31 32 2f 32 31 2f 31 38 00 38 00 01 00 2f 00 .12/21/18.8... + + At least three bytes are required, for the msg type and command, + with additional bytes optional for additional data. diff --git a/drivers/platform/chrome/wilco_ec/Kconfig b/drivers/platform/chrome/wilco_ec/Kconfig index 20945a301ec6..56b871510c4d 100644 --- a/drivers/platform/chrome/wilco_ec/Kconfig +++ b/drivers/platform/chrome/wilco_ec/Kconfig @@ -9,3 +9,12 @@ config WILCO_EC To compile this driver as a module, choose M here: the module will be called wilco_ec. + +config WILCO_EC_DEBUGFS + tristate "Enable raw access to EC via debugfs" + depends on WILCO_EC + help + If you say Y here, you get support for sending raw commands to + the Wilco EC via debugfs. These commands do not do any byte + manipulation and allow for testing arbitrary commands. This + interface is intended for debug only and is disabled by default. diff --git a/drivers/platform/chrome/wilco_ec/Makefile b/drivers/platform/chrome/wilco_ec/Makefile index 03b32301dc61..063e7fb4ea17 100644 --- a/drivers/platform/chrome/wilco_ec/Makefile +++ b/drivers/platform/chrome/wilco_ec/Makefile @@ -2,3 +2,5 @@ wilco_ec-objs := core.o mailbox.o obj-$(CONFIG_WILCO_EC) += wilco_ec.o +wilco_ec_debugfs-objs := debugfs.o +obj-$(CONFIG_WILCO_EC_DEBUGFS) += wilco_ec_debugfs.o diff --git a/drivers/platform/chrome/wilco_ec/core.c b/drivers/platform/chrome/wilco_ec/core.c index 7dcb3bde132a..e036d88b6dd8 100644 --- a/drivers/platform/chrome/wilco_ec/core.c +++ b/drivers/platform/chrome/wilco_ec/core.c @@ -44,6 +44,8 @@ static int wilco_ec_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct wilco_ec_device *ec; + struct platform_device *child_pdev; + int ret; ec = devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL); if (!ec) @@ -71,7 +73,25 @@ static int wilco_ec_probe(struct platform_device *pdev) cros_ec_lpc_mec_init(ec->io_packet->start, ec->io_packet->start + EC_MAILBOX_DATA_SIZE); + /* + * Register a debugfs platform device that will get picked up by the + * debugfs driver. This platform device will get freed when its parent + * device dev is unregistered. + */ + child_pdev = platform_device_register_data(dev, "wilco-ec-debugfs", + PLATFORM_DEVID_AUTO, + NULL, 0); + if (IS_ERR(child_pdev)) { + dev_err(dev, "Failed to create debugfs platform device\n"); + ret = PTR_ERR(child_pdev); + goto destroy_mec; + } + return 0; + +destroy_mec: + cros_ec_lpc_mec_destroy(); + return ret; } static int wilco_ec_remove(struct platform_device *pdev) diff --git a/drivers/platform/chrome/wilco_ec/debugfs.c b/drivers/platform/chrome/wilco_ec/debugfs.c new file mode 100644 index 000000000000..6c12cd093209 --- /dev/null +++ b/drivers/platform/chrome/wilco_ec/debugfs.c @@ -0,0 +1,226 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * debugfs attributes for Wilco EC + * + * Copyright 2019 Google LLC + * + * There is only one attribute used for debugging, called raw. + * You can write a hexadecimal sentence to raw, and that series of bytes + * will be sent to the EC. Then, you can read the bytes of response + * by reading from raw. + */ + +#include <linux/ctype.h> +#include <linux/debugfs.h> +#include <linux/fs.h> +#include <linux/module.h> +#include <linux/platform_data/wilco-ec.h> +#include <linux/platform_device.h> + +#define DRV_NAME "wilco-ec-debugfs" + +/* The 256 raw bytes will take up more space when represented as a hex string */ +#define FORMATTED_BUFFER_SIZE (EC_MAILBOX_DATA_SIZE_EXTENDED * 4) + +struct wilco_ec_debugfs { + struct wilco_ec_device *ec; + struct dentry *dir; + size_t response_size; + u8 raw_data[EC_MAILBOX_DATA_SIZE_EXTENDED]; + u8 formatted_data[FORMATTED_BUFFER_SIZE]; +}; + +static struct wilco_ec_debugfs *debug_info; + +/** + * parse_hex_sentence() - Convert a ascii hex representation into byte array + * @in: Input buffer of ascii + * @isize: Length of input buffer + * @out: Output buffer + * @osize: Length of output buffer, e.g. max number of bytes to parse + * + * An valid input is a series of ascii hexadecimal numbers, separated by spaces. + * An example valid input is + * " 00 f2 0 000076 6 0 ff" + * + * If an individual "word" within the hex sentence is longer than MAX_WORD_SIZE, + * then the sentence is illegal, and parsing will fail. + * + * Return: Number of bytes parsed, or negative error code on failure + */ +static int parse_hex_sentence(const char *in, int isize, u8 *out, int osize) +{ + int n_parsed = 0; + int word_start = 0; + int word_end; + int word_len; + /* Temp buffer for holding a "word" of chars that represents one byte */ + const static int MAX_WORD_SIZE = 16; + char tmp[MAX_WORD_SIZE+1]; + u8 byte; + + while (word_start < isize && n_parsed < osize) { + /* Find the start of the next word */ + while (word_start < isize && isspace(in[word_start])) + word_start++; + /* reached the end of the input before next word? */ + if (word_start >= isize) + break; + + /* Find the end of this word */ + word_end = word_start; + while (word_end < isize && !isspace(in[word_end])) + word_end++; + + /* Copy to a tmp NULL terminated string */ + word_len = word_end - word_start; + if (word_len > MAX_WORD_SIZE) + return -EINVAL; + memcpy(tmp, in + word_start, word_len); + tmp[word_len] = '\0'; + + /* + * Convert from hex string, place in output. If fails to parse, + * just return -EINVAL because specific error code is only + * relevant for this one word, returning it would be confusing. + */ + if (kstrtou8(tmp, 16, &byte)) + return -EINVAL; + out[n_parsed++] = byte; + + word_start = word_end; + } + return n_parsed; +} + +/* The message type takes up two bytes and the command takes a byte */ +#define CMDS_AND_DATA_SIZE ((EC_MAILBOX_DATA_SIZE) + 3) + +static ssize_t raw_write(struct file *file, const char __user *user_buf, + size_t count, loff_t *ppos) +{ + char *buf = debug_info->formatted_data; + struct wilco_ec_message msg; + u8 request_data[CMDS_AND_DATA_SIZE]; + ssize_t kcount; + int ret; + + if (count > FORMATTED_BUFFER_SIZE) + return -EINVAL; + + kcount = simple_write_to_buffer(buf, FORMATTED_BUFFER_SIZE, ppos, + user_buf, count); + if (kcount < 0) + return kcount; + + ret = parse_hex_sentence(buf, kcount, request_data, CMDS_AND_DATA_SIZE); + if (ret < 0) + return ret; + /* Need at least three bytes for type and command */ + if (ret < 3) + return -EINVAL; + + /* Clear response data buffer */ + memset(debug_info->raw_data, '\0', EC_MAILBOX_DATA_SIZE_EXTENDED); + + msg.type = request_data[0] << 8 | request_data[1]; + msg.flags = WILCO_EC_FLAG_RAW; + msg.command = request_data[2]; + msg.request_data = ret > 3 ? request_data + 3 : NULL; + msg.request_size = ret - 3; + msg.response_data = debug_info->raw_data; + msg.response_size = EC_MAILBOX_DATA_SIZE; + + /* Telemetry commands use extended response data */ + if (msg.type == WILCO_EC_MSG_TELEMETRY) { + msg.flags |= WILCO_EC_FLAG_EXTENDED_DATA; + msg.response_size = EC_MAILBOX_DATA_SIZE_EXTENDED; + } + + ret = wilco_ec_mailbox(debug_info->ec, &msg); + if (ret < 0) + return ret; + debug_info->response_size = ret; + + return count; +} + +/** + * wilco_ec_raw_show() - Show result from previous call to raw_store() + * @dev: Device representing the EC + * @attr: The attribute in question + * @buf: Output buffer to be filled + * + * Example usage: + * // Call raw_store(), read EC info type 3 (EC firmware build date) + * # echo 00 f0 38 00 03 00 > raw + * // Call this function, view the result. The decoded ASCII result + * // "12/21/18" is included after the raw hex. + * # cat raw + * 00 31 32 2f 32 31 2f 31 38 00 38 00 01 00 2f 00 .12/21/18.8.../. + * + * Return: Number of bytes written to output, negative error code on failure + */ +static ssize_t raw_read(struct file *file, char __user *user_buf, size_t count, + loff_t *ppos) +{ + int fmt_len = 0; + + if (debug_info->response_size) { + fmt_len = hex_dump_to_buffer(debug_info->raw_data, + debug_info->response_size, + 16, 1, debug_info->formatted_data, + FORMATTED_BUFFER_SIZE, true); + /* Only return response the first time it is read */ + debug_info->response_size = 0; + } + + return simple_read_from_buffer(user_buf, count, ppos, + debug_info->formatted_data, fmt_len); +} + +static const struct file_operations fops_raw = { + .owner = THIS_MODULE, + .read = raw_read, + .write = raw_write, + .llseek = no_llseek, +}; + +static int wilco_ec_debugfs_probe(struct platform_device *pdev) +{ + /* + * Ignore all errors, if there's a problem then we're already on fire: + * www.mail-archive.com/linux-kernel@vger.kernel.org/msg1906997.html + */ + struct wilco_ec_device *ec = dev_get_drvdata(pdev->dev.parent); + + debug_info = devm_kzalloc(&pdev->dev, sizeof(*debug_info), GFP_KERNEL); + debug_info->ec = ec; + debug_info->dir = debugfs_create_dir("wilco_ec", NULL); + debugfs_create_file("raw", 0644, debug_info->dir, NULL, &fops_raw); + + return 0; +} + +static int wilco_ec_debugfs_remove(struct platform_device *pdev) +{ + if (debug_info) + debugfs_remove_recursive(debug_info->dir); + + return 0; +} + +static struct platform_driver wilco_ec_debugfs_driver = { + .driver = { + .name = DRV_NAME, + }, + .probe = wilco_ec_debugfs_probe, + .remove = wilco_ec_debugfs_remove, +}; + +module_platform_driver(wilco_ec_debugfs_driver); + +MODULE_ALIAS("platform:" DRV_NAME); +MODULE_AUTHOR("Nick Crews <ncrews@chromium.org>"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Wilco EC debugfs driver");