hwmon: (pwm-fan) split __set_pwm into locked/unlocked functions

Regular calls to set_pwm don't hold the mutex, but the upcoming
update_enable support needs to call set_pwm with the mutex being held.
So provide the previous behavior in set_pwm (handling the lock), while
adding __set_pwm which assumes the lock being held.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220914153137.613982-5-alexander.stein@ew.tq-group.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 92c5b7f5ddd666c01c64af0584150b4cc20c4161..12ef3b3dbe2294c3dc7b69d2b4da1c8fcf5a4ad3 100644 (file)
--- a/drivers/hwmon/pwm-fan.c
+++ b/drivers/hwmon/pwm-fan.c
@@ -152,14 +152,12 @@ static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
        unsigned long period;
        int ret = 0;
 
-       mutex_lock(&ctx->lock);
-
        if (pwm > 0) {
                period = state->period;
                state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
                ret = pwm_apply_state(ctx->pwm, state);
                if (ret)
-                       goto exit_set_pwm_err;
+                       return ret;
                ret = pwm_fan_power_on(ctx);
        } else {
                ret = pwm_fan_power_off(ctx);
@@ -167,8 +165,17 @@ static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
        if (!ret)
                ctx->pwm_value = pwm;
 
-exit_set_pwm_err:
+       return ret;
+}
+
+static int set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
+{
+       int ret;
+
+       mutex_lock(&ctx->lock);
+       ret = __set_pwm(ctx, pwm);
        mutex_unlock(&ctx->lock);
+
        return ret;
 }
 
@@ -192,7 +199,7 @@ static int pwm_fan_write(struct device *dev, enum hwmon_sensor_types type,
        if (val < 0 || val > MAX_PWM)
                return -EINVAL;
 
-       ret = __set_pwm(ctx, val);
+       ret = set_pwm(ctx, val);
        if (ret)
                return ret;
 
@@ -280,7 +287,7 @@ pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
        if (state == ctx->pwm_fan_state)
                return 0;
 
-       ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
+       ret = set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
        if (ret) {
                dev_err(&cdev->device, "Cannot set pwm!\n");
                return ret;
@@ -398,7 +405,7 @@ static int pwm_fan_probe(struct platform_device *pdev)
        pwm_init_state(ctx->pwm, &ctx->pwm_state);
 
        /*
-        * __set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned
+        * set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned
         * long. Check this here to prevent the fan running at a too low
         * frequency.
         */
@@ -408,7 +415,7 @@ static int pwm_fan_probe(struct platform_device *pdev)
        }
 
        /* Set duty cycle to maximum allowed and enable PWM output */
-       ret = __set_pwm(ctx, MAX_PWM);
+       ret = set_pwm(ctx, MAX_PWM);
        if (ret) {
                dev_err(dev, "Failed to configure PWM: %d\n", ret);
                return ret;