Re: [PATCH v2 1/3] hwmon: (gpd-fan): drop global driver data and use per-device allocation

[Pei Xiao <xiaopei01@kylinos.cn>]

在 2026/5/27 16:10, xiaopeitux@foxmail.com 写道:
> From: Pei Xiao <xiaopei01@kylinos.cn>
>
> replace the global state gpd_driver_priv with per-device private data
> (struct gpd_fan_data) allocated in probe. This allows the driver to
> support multiple instances in the future and aligns with kernel best
> practices.
>
> No functional change intended.
>
> Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn>
> ---
> changs in v2: 
> 1.move gpd_init_ec before register hwmon device
igore this, thanks!
> 2.platform_create_bundle pass a driver_data  pointer to
> ---
>  drivers/hwmon/gpd-fan.c | 209 ++++++++++++++++++++++------------------
>  1 file changed, 115 insertions(+), 94 deletions(-)
>
> diff --git a/drivers/hwmon/gpd-fan.c b/drivers/hwmon/gpd-fan.c
> index 80de5f20781e..7284babd4f5c 100644
> --- a/drivers/hwmon/gpd-fan.c
> +++ b/drivers/hwmon/gpd-fan.c
> @@ -40,12 +40,11 @@ enum FAN_PWM_ENABLE {
>  	AUTOMATIC	= 2,
>  };
>  
> -static struct {
> +struct gpd_fan_data {
>  	enum FAN_PWM_ENABLE pwm_enable;
>  	u8 pwm_value;
> -
>  	const struct gpd_fan_drvdata *drvdata;
> -} gpd_driver_priv;
> +};
>  
>  struct gpd_fan_drvdata {
>  	const char *board_name; // Board name for module param comparison
> @@ -249,10 +248,10 @@ static const struct gpd_fan_drvdata *gpd_module_drvdata[] = {
>  };
>  
>  // Helper functions to handle EC read/write
> -static void gpd_ecram_read(u16 offset, u8 *val)
> +static void gpd_ecram_read(const struct gpd_fan_drvdata *drvdata, u16 offset, u8 *val)
>  {
> -	u16 addr_port = gpd_driver_priv.drvdata->addr_port;
> -	u16 data_port = gpd_driver_priv.drvdata->data_port;
> +	u16 addr_port = drvdata->addr_port;
> +	u16 data_port = drvdata->data_port;
>  
>  	outb(0x2E, addr_port);
>  	outb(0x11, data_port);
> @@ -270,10 +269,10 @@ static void gpd_ecram_read(u16 offset, u8 *val)
>  	*val = inb(data_port);
>  }
>  
> -static void gpd_ecram_write(u16 offset, u8 value)
> +static void gpd_ecram_write(const struct gpd_fan_drvdata *drvdata, u16 offset, u8 value)
>  {
> -	u16 addr_port = gpd_driver_priv.drvdata->addr_port;
> -	u16 data_port = gpd_driver_priv.drvdata->data_port;
> +	u16 addr_port = drvdata->addr_port;
> +	u16 data_port = drvdata->data_port;
>  
>  	outb(0x2E, addr_port);
>  	outb(0x11, data_port);
> @@ -291,198 +290,198 @@ static void gpd_ecram_write(u16 offset, u8 value)
>  	outb(value, data_port);
>  }
>  
> -static int gpd_generic_read_rpm(void)
> +static int gpd_generic_read_rpm(struct gpd_fan_data *data)
>  {
> -	const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
> +	const struct gpd_fan_drvdata *drvdata = data->drvdata;
>  	u8 high, low;
>  
> -	gpd_ecram_read(drvdata->rpm_read, &high);
> -	gpd_ecram_read(drvdata->rpm_read + 1, &low);
> +	gpd_ecram_read(drvdata, drvdata->rpm_read, &high);
> +	gpd_ecram_read(drvdata, drvdata->rpm_read + 1, &low);
>  
>  	return (u16)high << 8 | low;
>  }
>  
> -static int gpd_wm2_read_rpm(void)
> +static int gpd_wm2_read_rpm(struct gpd_fan_data *data)
>  {
> +	const struct gpd_fan_drvdata *drvdata = data->drvdata;
> +
>  	for (u16 pwm_ctr_offset = GPD_PWM_CTR_OFFSET;
>  	     pwm_ctr_offset <= GPD_PWM_CTR_OFFSET + 2; pwm_ctr_offset++) {
>  		u8 PWMCTR;
>  
> -		gpd_ecram_read(pwm_ctr_offset, &PWMCTR);
> +		gpd_ecram_read(drvdata, pwm_ctr_offset, &PWMCTR);
>  
>  		if (PWMCTR != 0xB8)
> -			gpd_ecram_write(pwm_ctr_offset, 0xB8);
> +			gpd_ecram_write(drvdata, pwm_ctr_offset, 0xB8);
>  	}
>  
> -	return gpd_generic_read_rpm();
> +	return gpd_generic_read_rpm(data);
>  }
>  
>  // Read value for fan1_input
> -static int gpd_read_rpm(void)
> +static int gpd_read_rpm(struct gpd_fan_data *data)
>  {
> -	switch (gpd_driver_priv.drvdata->board) {
> +	switch (data->drvdata->board) {
>  	case win4_6800u:
>  	case win_mini:
>  	case duo:
>  	case mpc2:
> -		return gpd_generic_read_rpm();
> +		return gpd_generic_read_rpm(data);
>  	case win_max_2:
> -		return gpd_wm2_read_rpm();
> +		return gpd_wm2_read_rpm(data);
>  	}
>  
>  	return 0;
>  }
>  
> -static int gpd_wm2_read_pwm(void)
> +static int gpd_wm2_read_pwm(struct gpd_fan_data *data)
>  {
> -	const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
> +	const struct gpd_fan_drvdata *drvdata = data->drvdata;
>  	u8 var;
>  
> -	gpd_ecram_read(drvdata->pwm_write, &var);
> +	gpd_ecram_read(drvdata, drvdata->pwm_write, &var);
>  
>  	// Match gpd_generic_write_pwm(u8) below
>  	return DIV_ROUND_CLOSEST((var - 1) * 255, (drvdata->pwm_max - 1));
>  }
>  
>  // Read value for pwm1
> -static int gpd_read_pwm(void)
> +static int gpd_read_pwm(struct gpd_fan_data *data)
>  {
> -	switch (gpd_driver_priv.drvdata->board) {
> +	switch (data->drvdata->board) {
>  	case win_mini:
>  	case duo:
>  	case win4_6800u:
>  	case mpc2:
> -		switch (gpd_driver_priv.pwm_enable) {
> +		switch (data->pwm_enable) {
>  		case DISABLE:
>  			return 255;
>  		case MANUAL:
> -			return gpd_driver_priv.pwm_value;
> +			return data->pwm_value;
>  		case AUTOMATIC:
>  			return -EOPNOTSUPP;
>  		}
>  		break;
>  	case win_max_2:
> -		return gpd_wm2_read_pwm();
> +		return gpd_wm2_read_pwm(data);
>  	}
>  	return 0;
>  }
>  
>  // PWM value's range in EC is 1 - pwm_max, cast 0 - 255 to it.
> -static inline u8 gpd_cast_pwm_range(u8 val)
> +static inline u8 gpd_cast_pwm_range(const struct gpd_fan_drvdata *drvdata, u8 val)
>  {
> -	const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
> -
>  	return DIV_ROUND_CLOSEST(val * (drvdata->pwm_max - 1), 255) + 1;
>  }
>  
> -static void gpd_generic_write_pwm(u8 val)
> +static void gpd_generic_write_pwm(struct gpd_fan_data *data, u8 val)
>  {
> -	const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
> +	const struct gpd_fan_drvdata *drvdata = data->drvdata;
>  	u8 pwm_reg;
>  
> -	pwm_reg = gpd_cast_pwm_range(val);
> -	gpd_ecram_write(drvdata->pwm_write, pwm_reg);
> +	pwm_reg = gpd_cast_pwm_range(drvdata, val);
> +	gpd_ecram_write(drvdata, drvdata->pwm_write, pwm_reg);
>  }
>  
> -static void gpd_duo_write_pwm(u8 val)
> +static void gpd_duo_write_pwm(struct gpd_fan_data *data, u8 val)
>  {
> -	const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
> +	const struct gpd_fan_drvdata *drvdata = data->drvdata;
>  	u8 pwm_reg;
>  
> -	pwm_reg = gpd_cast_pwm_range(val);
> -	gpd_ecram_write(drvdata->pwm_write, pwm_reg);
> -	gpd_ecram_write(drvdata->pwm_write + 1, pwm_reg);
> +	pwm_reg = gpd_cast_pwm_range(drvdata, val);
> +	gpd_ecram_write(drvdata, drvdata->pwm_write, pwm_reg);
> +	gpd_ecram_write(drvdata, drvdata->pwm_write + 1, pwm_reg);
>  }
>  
>  // Write value for pwm1
> -static int gpd_write_pwm(u8 val)
> +static int gpd_write_pwm(struct gpd_fan_data *data, u8 val)
>  {
> -	if (gpd_driver_priv.pwm_enable != MANUAL)
> +	if (data->pwm_enable != MANUAL)
>  		return -EPERM;
>  
> -	switch (gpd_driver_priv.drvdata->board) {
> +	switch (data->drvdata->board) {
>  	case duo:
> -		gpd_duo_write_pwm(val);
> +		gpd_duo_write_pwm(data, val);
>  		break;
>  	case win_mini:
>  	case win4_6800u:
>  	case win_max_2:
>  	case mpc2:
> -		gpd_generic_write_pwm(val);
> +		gpd_generic_write_pwm(data, val);
>  		break;
>  	}
>  
>  	return 0;
>  }
>  
> -static void gpd_win_mini_set_pwm_enable(enum FAN_PWM_ENABLE pwm_enable)
> +static void gpd_win_mini_set_pwm_enable(struct gpd_fan_data *data, enum FAN_PWM_ENABLE pwm_enable)
>  {
>  	switch (pwm_enable) {
>  	case DISABLE:
> -		gpd_generic_write_pwm(255);
> +		gpd_generic_write_pwm(data, 255);
>  		break;
>  	case MANUAL:
> -		gpd_generic_write_pwm(gpd_driver_priv.pwm_value);
> +		gpd_generic_write_pwm(data, data->pwm_value);
>  		break;
>  	case AUTOMATIC:
> -		gpd_ecram_write(gpd_driver_priv.drvdata->pwm_write, 0);
> +		gpd_ecram_write(data->drvdata, data->drvdata->pwm_write, 0);
>  		break;
>  	}
>  }
>  
> -static void gpd_duo_set_pwm_enable(enum FAN_PWM_ENABLE pwm_enable)
> +static void gpd_duo_set_pwm_enable(struct gpd_fan_data *data, enum FAN_PWM_ENABLE pwm_enable)
>  {
>  	switch (pwm_enable) {
>  	case DISABLE:
> -		gpd_duo_write_pwm(255);
> +		gpd_duo_write_pwm(data, 255);
>  		break;
>  	case MANUAL:
> -		gpd_duo_write_pwm(gpd_driver_priv.pwm_value);
> +		gpd_duo_write_pwm(data, data->pwm_value);
>  		break;
>  	case AUTOMATIC:
> -		gpd_ecram_write(gpd_driver_priv.drvdata->pwm_write, 0);
> +		gpd_ecram_write(data->drvdata, data->drvdata->pwm_write, 0);
>  		break;
>  	}
>  }
>  
> -static void gpd_wm2_set_pwm_enable(enum FAN_PWM_ENABLE enable)
> +static void gpd_wm2_set_pwm_enable(struct gpd_fan_data *data, enum FAN_PWM_ENABLE enable)
>  {
> -	const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
> +	const struct gpd_fan_drvdata *drvdata = data->drvdata;
>  
>  	switch (enable) {
>  	case DISABLE:
> -		gpd_generic_write_pwm(255);
> -		gpd_ecram_write(drvdata->manual_control_enable, 1);
> +		gpd_generic_write_pwm(data, 255);
> +		gpd_ecram_write(drvdata, drvdata->manual_control_enable, 1);
>  		break;
>  	case MANUAL:
> -		gpd_generic_write_pwm(gpd_driver_priv.pwm_value);
> -		gpd_ecram_write(drvdata->manual_control_enable, 1);
> +		gpd_generic_write_pwm(data, data->pwm_value);
> +		gpd_ecram_write(drvdata, drvdata->manual_control_enable, 1);
>  		break;
>  	case AUTOMATIC:
> -		gpd_ecram_write(drvdata->manual_control_enable, 0);
> +		gpd_ecram_write(drvdata, drvdata->manual_control_enable, 0);
>  		break;
>  	}
>  }
>  
>  // Write value for pwm1_enable
> -static void gpd_set_pwm_enable(enum FAN_PWM_ENABLE enable)
> +static void gpd_set_pwm_enable(struct gpd_fan_data *data, enum FAN_PWM_ENABLE enable)
>  {
>  	if (enable == MANUAL)
>  		// Set pwm_value to max firstly when switching to manual mode, in
>  		// consideration of device safety.
> -		gpd_driver_priv.pwm_value = 255;
> +		data->pwm_value = 255;
>  
> -	switch (gpd_driver_priv.drvdata->board) {
> +	switch (data->drvdata->board) {
>  	case win_mini:
>  	case win4_6800u:
>  	case mpc2:
> -		gpd_win_mini_set_pwm_enable(enable);
> +		gpd_win_mini_set_pwm_enable(data, enable);
>  		break;
>  	case duo:
> -		gpd_duo_set_pwm_enable(enable);
> +		gpd_duo_set_pwm_enable(data, enable);
>  		break;
>  	case win_max_2:
> -		gpd_wm2_set_pwm_enable(enable);
> +		gpd_wm2_set_pwm_enable(data, enable);
>  		break;
>  	}
>  }
> @@ -505,15 +504,16 @@ static umode_t gpd_fan_hwmon_is_visible(__always_unused const void *drvdata,
>  	return 0;
>  }
>  
> -static int gpd_fan_hwmon_read(__always_unused struct device *dev,
> +static int gpd_fan_hwmon_read(struct device *dev,
>  			      enum hwmon_sensor_types type, u32 attr,
>  			      __always_unused int channel, long *val)
>  {
> +	struct gpd_fan_data *data = dev_get_drvdata(dev);
>  	int ret;
>  
>  	if (type == hwmon_fan) {
>  		if (attr == hwmon_fan_input) {
> -			ret = gpd_read_rpm();
> +			ret = gpd_read_rpm(data);
>  
>  			if (ret < 0)
>  				return ret;
> @@ -524,10 +524,10 @@ static int gpd_fan_hwmon_read(__always_unused struct device *dev,
>  	} else if (type == hwmon_pwm) {
>  		switch (attr) {
>  		case hwmon_pwm_enable:
> -			*val = gpd_driver_priv.pwm_enable;
> +			*val = data->pwm_enable;
>  			return 0;
>  		case hwmon_pwm_input:
> -			ret = gpd_read_pwm();
> +			ret = gpd_read_pwm(data);
>  
>  			if (ret < 0)
>  				return ret;
> @@ -540,27 +540,29 @@ static int gpd_fan_hwmon_read(__always_unused struct device *dev,
>  	return -EOPNOTSUPP;
>  }
>  
> -static int gpd_fan_hwmon_write(__always_unused struct device *dev,
> +static int gpd_fan_hwmon_write(struct device *dev,
>  			       enum hwmon_sensor_types type, u32 attr,
>  			       __always_unused int channel, long val)
>  {
> +	struct gpd_fan_data *data = dev_get_drvdata(dev);
> +
>  	if (type == hwmon_pwm) {
>  		switch (attr) {
>  		case hwmon_pwm_enable:
>  			if (!in_range(val, 0, 3))
>  				return -EINVAL;
>  
> -			gpd_driver_priv.pwm_enable = val;
> +			data->pwm_enable = val;
>  
> -			gpd_set_pwm_enable(gpd_driver_priv.pwm_enable);
> +			gpd_set_pwm_enable(data, data->pwm_enable);
>  			return 0;
>  		case hwmon_pwm_input:
>  			if (!in_range(val, 0, 256))
>  				return -EINVAL;
>  
> -			gpd_driver_priv.pwm_value = val;
> +			data->pwm_value = val;
>  
> -			return gpd_write_pwm(val);
> +			return gpd_write_pwm(data, val);
>  		}
>  	}
>  
> @@ -584,26 +586,27 @@ static struct hwmon_chip_info gpd_fan_chip_info = {
>  	.info = gpd_fan_hwmon_channel_info
>  };
>  
> -static void gpd_win4_init_ec(void)
> +static void gpd_win4_init_ec(struct gpd_fan_data *data)
>  {
> +	const struct gpd_fan_drvdata *drvdata = data->drvdata;
>  	u8 chip_id, chip_ver;
>  
> -	gpd_ecram_read(0x2000, &chip_id);
> +	gpd_ecram_read(drvdata, 0x2000, &chip_id);
>  
>  	if (chip_id == 0x55) {
> -		gpd_ecram_read(0x1060, &chip_ver);
> -		gpd_ecram_write(0x1060, chip_ver | 0x80);
> +		gpd_ecram_read(drvdata, 0x1060, &chip_ver);
> +		gpd_ecram_write(drvdata, 0x1060, chip_ver | 0x80);
>  	}
>  }
>  
> -static void gpd_init_ec(void)
> +static void gpd_init_ec(struct gpd_fan_data *data)
>  {
>  	// The buggy firmware won't initialize EC properly on boot.
>  	// Before its initialization, reading RPM will always return 0,
>  	// and writing PWM will have no effect.
>  	// Initialize it manually on driver load.
> -	if (gpd_driver_priv.drvdata->board == win4_6800u)
> -		gpd_win4_init_ec();
> +	if (data->drvdata->board == win4_6800u)
> +		gpd_win4_init_ec(data);
>  }
>  
>  static int gpd_fan_probe(struct platform_device *pdev)
> @@ -611,7 +614,9 @@ static int gpd_fan_probe(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	const struct resource *region;
>  	const struct resource *res;
> -	const struct device *hwdev;
> +	struct device *hwdev;
> +	struct gpd_fan_data *data;
> +	const struct gpd_fan_drvdata *match;
>  
>  	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
>  	if (!res)
> @@ -624,24 +629,42 @@ static int gpd_fan_probe(struct platform_device *pdev)
>  		return dev_err_probe(dev, -EBUSY,
>  				     "Failed to request region\n");
>  
> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	match = dev_get_platdata(dev);
> +	if (!match)
> +		return -EINVAL;
> +
> +	data->drvdata = match;
> +	data->pwm_enable = AUTOMATIC;
> +	data->pwm_value = 255;
> +
> +	dev_set_drvdata(dev, data);
> +
>  	hwdev = devm_hwmon_device_register_with_info(dev,
>  						     DRIVER_NAME,
> -						     NULL,
> +						     data,
>  						     &gpd_fan_chip_info,
>  						     NULL);
>  	if (IS_ERR(hwdev))
>  		return dev_err_probe(dev, PTR_ERR(hwdev),
>  				     "Failed to register hwmon device\n");
>  
> -	gpd_init_ec();
> +	gpd_init_ec(data);
>  
>  	return 0;
>  }
>  
> -static void gpd_fan_remove(__always_unused struct platform_device *pdev)
> +static void gpd_fan_remove(struct platform_device *pdev)
>  {
> -	gpd_driver_priv.pwm_enable = AUTOMATIC;
> -	gpd_set_pwm_enable(AUTOMATIC);
> +	struct gpd_fan_data *data = dev_get_drvdata(&pdev->dev);
> +
> +	if (data) {
> +		data->pwm_enable = AUTOMATIC;
> +		gpd_set_pwm_enable(data, AUTOMATIC);
> +	}
>  }
>  
>  static struct platform_driver gpd_fan_driver = {
> @@ -668,6 +691,7 @@ static int __init gpd_fan_init(void)
>  	if (!match) {
>  		const struct dmi_system_id *dmi_match =
>  			dmi_first_match(dmi_table);
> +
>  		if (dmi_match)
>  			match = dmi_match->driver_data;
>  	}
> @@ -675,10 +699,6 @@ static int __init gpd_fan_init(void)
>  	if (!match)
>  		return -ENODEV;
>  
> -	gpd_driver_priv.pwm_enable = AUTOMATIC;
> -	gpd_driver_priv.pwm_value = 255;
> -	gpd_driver_priv.drvdata = match;
> -
>  	struct resource gpd_fan_resources[] = {
>  		{
>  			.start = match->addr_port,
> @@ -690,7 +710,8 @@ static int __init gpd_fan_init(void)
>  	gpd_fan_platform_device = platform_create_bundle(&gpd_fan_driver,
>  							 gpd_fan_probe,
>  							 gpd_fan_resources,
> -							 1, NULL, 0);
> +							 1,
> +							 match, sizeof(*match));
>  
>  	if (IS_ERR(gpd_fan_platform_device)) {
>  		pr_warn("Failed to create platform device\n");