On Fri May 2, 2025 at 9:45 AM -03, Ilpo Järvinen wrote: > On Fri, 2 May 2025, Kurt Borja via B4 Relay wrote: > >> From: Kurt Borja >> >> Devices with the AWCC interface come with a USB RGB-lighting STM32 MCU, >> which has two GPIO pins with debug capabilities: >> >> - Device Firmware Update mode (DFU) >> - Negative Reset (NRST) >> >> The WMAX device has methods to toggle or read the state of these GPIO >> pins. Expose these methods through DebugFS, hidden behind an unsafe >> module parameter to avoid common users from toying with these without >> consideration. >> >> Suggested-by: Gabriel Marcano >> Reviewed-by: Armin Wolf >> Signed-off-by: Kurt Borja >> --- >> Documentation/ABI/testing/debugfs-alienware-wmi | 20 +++++ >> drivers/platform/x86/dell/alienware-wmi-wmax.c | 105 +++++++++++++++++++++++- >> 2 files changed, 123 insertions(+), 2 deletions(-) >> >> diff --git a/Documentation/ABI/testing/debugfs-alienware-wmi b/Documentation/ABI/testing/debugfs-alienware-wmi >> index 48cfd4d0b002efd7b68d9c1d3aa91a3a05f49db5..c7f525d6baac962be82780608f8da5c0368600cc 100644 >> --- a/Documentation/ABI/testing/debugfs-alienware-wmi >> +++ b/Documentation/ABI/testing/debugfs-alienware-wmi >> @@ -42,3 +42,23 @@ Description: >> details. >> >> RO >> + >> +What: /sys/kernel/debug/alienware-wmi-/gpio_ctl/total_gpios >> +Date: May 2025 >> +KernelVersion: 6.16 >> +Contact: Kurt Borja >> +Description: >> + Total number of GPIO pins reported by the device. >> + >> + RO >> + >> +What: /sys/kernel/debug/alienware-wmi-/gpio_ctl/pinX >> +Date: May 2025 >> +KernelVersion: 6.16 >> +Contact: Kurt Borja >> +Description: >> + This file controls GPIO pin X status. >> + >> + See Documentation/wmi/devices/alienware-wmi.rst for details. >> + >> + RW >> diff --git a/drivers/platform/x86/dell/alienware-wmi-wmax.c b/drivers/platform/x86/dell/alienware-wmi-wmax.c >> index faeddfe3b79e0aa51e7c8c6b23aa4ac5c7218706..2bf9d85426b8f2cc5482be48050c81f9b6a30d00 100644 >> --- a/drivers/platform/x86/dell/alienware-wmi-wmax.c >> +++ b/drivers/platform/x86/dell/alienware-wmi-wmax.c >> @@ -38,6 +38,9 @@ >> #define AWCC_METHOD_GET_FAN_SENSORS 0x13 >> #define AWCC_METHOD_THERMAL_INFORMATION 0x14 >> #define AWCC_METHOD_THERMAL_CONTROL 0x15 >> +#define AWCC_METHOD_FWUP_GPIO_CONTROL 0x20 >> +#define AWCC_METHOD_READ_TOTAL_GPIOS 0x21 >> +#define AWCC_METHOD_READ_GPIO_STATUS 0x22 >> #define AWCC_METHOD_GAME_SHIFT_STATUS 0x25 >> >> #define AWCC_FAILURE_CODE 0xFFFFFFFF >> @@ -281,6 +284,8 @@ struct awcc_priv { >> struct device *hwdev; >> struct awcc_fan_data **fan_data; >> unsigned long temp_sensors[AWCC_ID_BITMAP_LONGS]; >> + >> + u32 gpio_count; >> }; >> >> static const enum platform_profile_option awcc_mode_to_platform_profile[AWCC_PROFILE_LAST] = { >> @@ -571,6 +576,38 @@ static int awcc_thermal_information(struct wmi_device *wdev, u8 operation, u8 ar >> return awcc_wmi_command(wdev, AWCC_METHOD_THERMAL_INFORMATION, &args, out); >> } >> >> +static int awcc_fwup_gpio_control(struct wmi_device *wdev, u8 pin, u8 status) >> +{ >> + struct wmax_u32_args args = { >> + .operation = pin, >> + .arg1 = status, >> + .arg2 = 0, >> + .arg3 = 0, >> + }; >> + u32 out; >> + >> + return awcc_wmi_command(wdev, AWCC_METHOD_FWUP_GPIO_CONTROL, &args, &out); >> +} >> + >> +static int awcc_read_total_gpios(struct wmi_device *wdev, u32 *count) >> +{ >> + struct wmax_u32_args args = {}; >> + >> + return awcc_wmi_command(wdev, AWCC_METHOD_READ_TOTAL_GPIOS, &args, count); >> +} >> + >> +static int awcc_read_gpio_status(struct wmi_device *wdev, u8 pin, u32 *status) >> +{ >> + struct wmax_u32_args args = { >> + .operation = pin, >> + .arg1 = 0, >> + .arg2 = 0, >> + .arg3 = 0, >> + }; >> + >> + return awcc_wmi_command(wdev, AWCC_METHOD_READ_GPIO_STATUS, &args, status); >> +} >> + >> static int awcc_game_shift_status(struct wmi_device *wdev, u8 operation, >> u32 *out) >> { >> @@ -1318,6 +1355,47 @@ static int awcc_debugfs_pprof_data_read(struct seq_file *seq, void *data) >> return 0; >> } >> >> +static int awcc_gpio_pin_show(struct seq_file *seq, void *data) >> +{ >> + unsigned long pin = debugfs_get_aux_num(seq->file); >> + struct wmi_device *wdev = seq->private; >> + u32 status; >> + int ret; >> + >> + ret = awcc_read_gpio_status(wdev, pin, &status); >> + if (ret) >> + return ret; >> + >> + seq_printf(seq, "%u\n", status); >> + >> + return 0; >> +} >> + >> +static ssize_t awcc_gpio_pin_write(struct file *file, const char __user *buf, >> + size_t count, loff_t *ppos) >> +{ >> + unsigned long pin = debugfs_get_aux_num(file); >> + struct seq_file *seq = file->private_data; >> + struct wmi_device *wdev = seq->private; >> + bool status; >> + int ret; >> + >> + if (!ppos || *ppos) >> + return -EINVAL; >> + >> + ret = kstrtobool_from_user(buf, count, &status); >> + if (ret) >> + return ret; >> + >> + ret = awcc_fwup_gpio_control(wdev, pin, status); >> + if (ret) >> + return ret; >> + >> + return count; >> +} >> + >> +DEFINE_SHOW_STORE_ATTRIBUTE(awcc_gpio_pin); >> + >> static void awcc_debugfs_remove(void *data) >> { >> struct dentry *root = data; >> @@ -1327,11 +1405,15 @@ static void awcc_debugfs_remove(void *data) >> >> static void awcc_debugfs_init(struct wmi_device *wdev) >> { >> - struct dentry *root; >> - char name[64]; >> + struct awcc_priv *priv = dev_get_drvdata(&wdev->dev); >> + struct dentry *root, *gpio_ctl; >> + char pin_name[8], name[64]; >> + u32 gpio_count; >> + int ret; >> >> scnprintf(name, sizeof(name), "%s-%s", "alienware-wmi", dev_name(&wdev->dev)); >> root = debugfs_create_dir(name, NULL); >> + gpio_ctl = debugfs_create_dir("gpio_ctl", root); >> >> debugfs_create_devm_seqfile(&wdev->dev, "system_description", root, >> awcc_debugfs_system_description_read); >> @@ -1344,6 +1426,25 @@ static void awcc_debugfs_init(struct wmi_device *wdev) >> debugfs_create_devm_seqfile(&wdev->dev, "pprof_data", root, >> awcc_debugfs_pprof_data_read); >> >> + ret = awcc_read_total_gpios(wdev, &gpio_count); >> + if (ret) { >> + dev_dbg(&wdev->dev, "Failed to get total GPIO Pin count\n"); >> + goto out_add_action; >> + } else if (gpio_count > AWCC_MAX_RES_COUNT) { >> + dev_dbg(&wdev->dev, "Reported GPIO Pin count may be corrupted: %u\n", gpio_count); >> + goto out_add_action; >> + } >> + >> + priv->gpio_count = gpio_count; >> + debugfs_create_u32("total_gpios", 0444, gpio_ctl, &priv->gpio_count); >> + >> + for (unsigned int i = 0; i < gpio_count; i++) { >> + scnprintf(pin_name, sizeof(pin_name), "pin%u", i); > > Hi, > > This might trigger a warning from the compiler that the resulting string > might not fit into pin_name. Did you check the warnings? Hi Ilpo, W=1 currently throws no warnings. gpio_count does not exceed AWCC_MAX_RES_COUNT (16) so it should fit into `pin_name` right? Anyway, to avoid this we can reuse `name[]` here instead. -- ~ Kurt > >> + debugfs_create_file_aux_num(pin_name, 0644, gpio_ctl, wdev, i, >> + &awcc_gpio_pin_fops); >> + } >> + >> +out_add_action: >> devm_add_action_or_reset(&wdev->dev, awcc_debugfs_remove, root); >> } >> >> >>