Re: [PATCH 1/2] platform/x86: alienware-wmi-wmax: Expose GPIO debug methods

["Kurt Borja" <kuurtb@gmail.com>]

On Sat Apr 26, 2025 at 10:07 PM -03, Armin Wolf wrote:
> Am 23.04.25 um 09:49 schrieb 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 <gabemarcano@yahoo.com>
>> Signed-off-by: Kurt Borja <kuurtb@gmail.com>
>> ---
>>   drivers/platform/x86/dell/alienware-wmi-wmax.c | 116 ++++++++++++++++++++++++-
>>   1 file changed, 115 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/platform/x86/dell/alienware-wmi-wmax.c b/drivers/platform/x86/dell/alienware-wmi-wmax.c
>> index faeddfe3b79e0aa51e7c8c6b23aa4ac5c7218706..2e83be02d7c5f8ca8176f1ec39d9929790da0844 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
>> @@ -65,6 +68,10 @@ static bool force_gmode;
>>   module_param_unsafe(force_gmode, bool, 0);
>>   MODULE_PARM_DESC(force_gmode, "Forces G-Mode when performance profile is selected");
>>   
>> +static bool gpio_debug;
>> +module_param_unsafe(gpio_debug, bool, 0);
>> +MODULE_PARM_DESC(gpio_debug, "Exposes GPIO debug methods to DebugFS");
>
> Hi,

Hi Armin,

>
> personally i thing that you can drop this module parameter. People using DebugFS should
> already know that they need to be careful.

I sure hope so. I know I was not careful when I started tinkering :p

I agree though, I'll drop it and follow your documentation suggestions.

>
> Other than that:
> Reviewed-by: Armin Wolf <W_Armin@gmx.de>

Thanks a lot!

-- 
 ~ Kurt

>
>> +
>>   struct awcc_quirks {
>>   	bool hwmon;
>>   	bool pprof;
>> @@ -217,6 +224,11 @@ enum AWCC_TEMP_SENSOR_TYPES {
>>   	AWCC_TEMP_SENSOR_GPU			= 0x06,
>>   };
>>   
>> +enum AWCC_GPIO_PINS {
>> +	AWCC_GPIO_PIN_DFU			= 0x00,
>> +	AWCC_GPIO_PIN_NRST			= 0x01,
>> +};
>> +
>>   enum awcc_thermal_profile {
>>   	AWCC_PROFILE_USTT_BALANCED,
>>   	AWCC_PROFILE_USTT_BALANCED_PERFORMANCE,
>> @@ -571,6 +583,38 @@ 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 +1362,63 @@ static int awcc_debugfs_pprof_data_read(struct seq_file *seq, void *data)
>>   	return 0;
>>   }
>>   
>> +static int awcc_debugfs_total_gpios_read(struct seq_file *seq, void *data)
>> +{
>> +	struct device *dev = seq->private;
>> +	struct wmi_device *wdev = to_wmi_device(dev);
>> +	u32 count;
>> +	int ret;
>> +
>> +	ret = awcc_read_total_gpios(wdev, &count);
>> +	if (ret)
>> +		return ret;
>> +
>> +	seq_printf(seq, "%u\n", count);
>> +
>> +	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;
>> @@ -1327,7 +1428,7 @@ static void awcc_debugfs_remove(void *data)
>>   
>>   static void awcc_debugfs_init(struct wmi_device *wdev)
>>   {
>> -	struct dentry *root;
>> +	struct dentry *root, *gpio_ctl;
>>   	char name[64];
>>   
>>   	scnprintf(name, sizeof(name), "%s-%s", "alienware-wmi", dev_name(&wdev->dev));
>> @@ -1344,6 +1445,19 @@ static void awcc_debugfs_init(struct wmi_device *wdev)
>>   		debugfs_create_devm_seqfile(&wdev->dev, "pprof_data", root,
>>   					    awcc_debugfs_pprof_data_read);
>>   
>> +	if (gpio_debug) {
>> +		gpio_ctl = debugfs_create_dir("gpio_ctl", root);
>> +
>> +		debugfs_create_devm_seqfile(&wdev->dev, "total_gpios", gpio_ctl,
>> +					    awcc_debugfs_total_gpios_read);
>> +		debugfs_create_file_aux_num("dfu_pin", 0644, gpio_ctl, wdev,
>> +					    AWCC_GPIO_PIN_DFU,
>> +					    &awcc_gpio_pin_fops);
>> +		debugfs_create_file_aux_num("nrst_pin", 0644, gpio_ctl, wdev,
>> +					    AWCC_GPIO_PIN_NRST,
>> +					    &awcc_gpio_pin_fops);
>> +	}
>> +
>>   	devm_add_action_or_reset(&wdev->dev, awcc_debugfs_remove, root);
>>   }
>>   
>>