[PATCH 1/3] hwmon: (gpd-fan): remove global variable gpd_driver_priv
From: Pei Xiao
Date: Sun Apr 05 2026 - 04:42:11 EST
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.
Signed-off-by: Pei Xiao <xiaopei01@xxxxxxxxxx>
---
drivers/hwmon/gpd-fan.c | 211 ++++++++++++++++++++++------------------
1 file changed, 116 insertions(+), 95 deletions(-)
diff --git a/drivers/hwmon/gpd-fan.c b/drivers/hwmon/gpd-fan.c
index 80de5f20781e..5a9d07cd29ab 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_ptr;
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_ptr = dev_get_platdata(dev);
+ if (!match_ptr)
+ return -EINVAL;
+ data->drvdata = *match_ptr;
+
+ data->pwm_enable = AUTOMATIC;
+ data->pwm_value = 255;
+
+ dev_set_drvdata(dev, data);
+
+ gpd_init_ec(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();
-
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");
--
2.25.1