aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/hwmon
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/pwm-fan.c210
1 files changed, 142 insertions, 68 deletions
diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 12ef3b3dbe22..498128eb81f1 100644
--- a/drivers/hwmon/pwm-fan.c
+++ b/drivers/hwmon/pwm-fan.c
@@ -28,6 +28,13 @@ struct pwm_fan_tach {
u8 pulses_per_revolution;
};
+enum pwm_fan_enable_mode {
+ pwm_off_reg_off,
+ pwm_disable_reg_enable,
+ pwm_enable_reg_enable,
+ pwm_disable_reg_disable,
+};
+
struct pwm_fan_ctx {
struct device *dev;
@@ -35,6 +42,7 @@ struct pwm_fan_ctx {
struct pwm_device *pwm;
struct pwm_state pwm_state;
struct regulator *reg_en;
+ enum pwm_fan_enable_mode enable_mode;
bool regulator_enabled;
bool enabled;
@@ -86,6 +94,29 @@ static void sample_timer(struct timer_list *t)
mod_timer(&ctx->rpm_timer, jiffies + HZ);
}
+static void pwm_fan_enable_mode_2_state(int enable_mode,
+ struct pwm_state *state,
+ bool *enable_regulator)
+{
+ switch (enable_mode) {
+ case pwm_disable_reg_enable:
+ /* disable pwm, keep regulator enabled */
+ state->enabled = false;
+ *enable_regulator = true;
+ break;
+ case pwm_enable_reg_enable:
+ /* keep pwm and regulator enabled */
+ state->enabled = true;
+ *enable_regulator = true;
+ break;
+ case pwm_off_reg_off:
+ case pwm_disable_reg_disable:
+ /* disable pwm and regulator */
+ state->enabled = false;
+ *enable_regulator = false;
+ }
+}
+
static int pwm_fan_switch_power(struct pwm_fan_ctx *ctx, bool on)
{
int ret = 0;
@@ -113,26 +144,41 @@ static int pwm_fan_power_on(struct pwm_fan_ctx *ctx)
if (ctx->enabled)
return 0;
+ ret = pwm_fan_switch_power(ctx, true);
+ if (ret < 0) {
+ dev_err(ctx->dev, "failed to enable power supply\n");
+ return ret;
+ }
+
state->enabled = true;
ret = pwm_apply_state(ctx->pwm, state);
if (ret) {
dev_err(ctx->dev, "failed to enable PWM\n");
- return ret;
+ goto disable_regulator;
}
ctx->enabled = true;
+ return 0;
+
+disable_regulator:
+ pwm_fan_switch_power(ctx, false);
return ret;
}
static int pwm_fan_power_off(struct pwm_fan_ctx *ctx)
{
struct pwm_state *state = &ctx->pwm_state;
+ bool enable_regulator = false;
int ret;
if (!ctx->enabled)
return 0;
+ pwm_fan_enable_mode_2_state(ctx->enable_mode,
+ state,
+ &enable_regulator);
+
state->enabled = false;
state->duty_cycle = 0;
ret = pwm_apply_state(ctx->pwm, state);
@@ -141,6 +187,8 @@ static int pwm_fan_power_off(struct pwm_fan_ctx *ctx)
return ret;
}
+ pwm_fan_switch_power(ctx, enable_regulator);
+
ctx->enabled = false;
return 0;
@@ -153,6 +201,10 @@ static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
int ret = 0;
if (pwm > 0) {
+ if (ctx->enable_mode == pwm_off_reg_off)
+ /* pwm-fan hard disabled */
+ return 0;
+
period = state->period;
state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
ret = pwm_apply_state(ctx->pwm, state);
@@ -190,20 +242,76 @@ static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
ctx->pwm_fan_state = i;
}
+static int pwm_fan_update_enable(struct pwm_fan_ctx *ctx, long val)
+{
+ int ret = 0;
+ int old_val;
+
+ mutex_lock(&ctx->lock);
+
+ if (ctx->enable_mode == val)
+ goto out;
+
+ old_val = ctx->enable_mode;
+ ctx->enable_mode = val;
+
+ if (val == 0) {
+ /* Disable pwm-fan unconditionally */
+ ret = __set_pwm(ctx, 0);
+ if (ret)
+ ctx->enable_mode = old_val;
+ pwm_fan_update_state(ctx, 0);
+ } else {
+ /*
+ * Change PWM and/or regulator state if currently disabled
+ * Nothing to do if currently enabled
+ */
+ if (!ctx->enabled) {
+ struct pwm_state *state = &ctx->pwm_state;
+ bool enable_regulator = false;
+
+ state->duty_cycle = 0;
+ pwm_fan_enable_mode_2_state(val,
+ state,
+ &enable_regulator);
+
+ pwm_apply_state(ctx->pwm, state);
+ pwm_fan_switch_power(ctx, enable_regulator);
+ pwm_fan_update_state(ctx, 0);
+ }
+ }
+out:
+ mutex_unlock(&ctx->lock);
+
+ return ret;
+}
+
static int pwm_fan_write(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long val)
{
struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
int ret;
- if (val < 0 || val > MAX_PWM)
- return -EINVAL;
+ switch (attr) {
+ case hwmon_pwm_input:
+ if (val < 0 || val > MAX_PWM)
+ return -EINVAL;
+ ret = set_pwm(ctx, val);
+ if (ret)
+ return ret;
+ pwm_fan_update_state(ctx, val);
+ break;
+ case hwmon_pwm_enable:
+ if (val < 0 || val > 3)
+ ret = -EINVAL;
+ else
+ ret = pwm_fan_update_enable(ctx, val);
- ret = set_pwm(ctx, val);
- if (ret)
return ret;
+ default:
+ return -EOPNOTSUPP;
+ }
- pwm_fan_update_state(ctx, val);
return 0;
}
@@ -214,9 +322,15 @@ static int pwm_fan_read(struct device *dev, enum hwmon_sensor_types type,
switch (type) {
case hwmon_pwm:
- *val = ctx->pwm_value;
- return 0;
-
+ switch (attr) {
+ case hwmon_pwm_input:
+ *val = ctx->pwm_value;
+ return 0;
+ case hwmon_pwm_enable:
+ *val = ctx->enable_mode;
+ return 0;
+ }
+ return -EOPNOTSUPP;
case hwmon_fan:
*val = ctx->tachs[channel].rpm;
return 0;
@@ -345,18 +459,14 @@ static int pwm_fan_of_get_cooling_data(struct device *dev,
return 0;
}
-static void pwm_fan_regulator_disable(void *data)
-{
- pwm_fan_switch_power(data, false);
-}
-
-static void pwm_fan_pwm_disable(void *__ctx)
+static void pwm_fan_cleanup(void *__ctx)
{
struct pwm_fan_ctx *ctx = __ctx;
- ctx->pwm_state.enabled = false;
- pwm_apply_state(ctx->pwm, &ctx->pwm_state);
del_timer_sync(&ctx->rpm_timer);
+ /* Switch off everything */
+ ctx->enable_mode = pwm_disable_reg_disable;
+ pwm_fan_power_off(ctx);
}
static int pwm_fan_probe(struct platform_device *pdev)
@@ -390,16 +500,6 @@ static int pwm_fan_probe(struct platform_device *pdev)
return PTR_ERR(ctx->reg_en);
ctx->reg_en = NULL;
- } else {
- ret = pwm_fan_switch_power(ctx, true);
- if (ret) {
- dev_err(dev, "Failed to enable fan supply: %d\n", ret);
- return ret;
- }
- ret = devm_add_action_or_reset(dev, pwm_fan_regulator_disable,
- ctx);
- if (ret)
- return ret;
}
pwm_init_state(ctx->pwm, &ctx->pwm_state);
@@ -414,14 +514,19 @@ static int pwm_fan_probe(struct platform_device *pdev)
return -EINVAL;
}
- /* Set duty cycle to maximum allowed and enable PWM output */
+ ctx->enable_mode = pwm_disable_reg_enable;
+
+ /*
+ * Set duty cycle to maximum allowed and enable PWM output as well as
+ * the regulator. In case of error nothing is changed
+ */
ret = set_pwm(ctx, MAX_PWM);
if (ret) {
dev_err(dev, "Failed to configure PWM: %d\n", ret);
return ret;
}
timer_setup(&ctx->rpm_timer, sample_timer, 0);
- ret = devm_add_action_or_reset(dev, pwm_fan_pwm_disable, ctx);
+ ret = devm_add_action_or_reset(dev, pwm_fan_cleanup, ctx);
if (ret)
return ret;
@@ -453,7 +558,7 @@ static int pwm_fan_probe(struct platform_device *pdev)
if (!channels)
return -ENOMEM;
- channels[0] = HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT);
+ channels[0] = HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT | HWMON_PWM_ENABLE);
for (i = 0; i < ctx->tach_count; i++) {
struct pwm_fan_tach *tach = &ctx->tachs[i];
@@ -527,57 +632,26 @@ static int pwm_fan_probe(struct platform_device *pdev)
return 0;
}
-static int pwm_fan_disable(struct device *dev)
-{
- struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
- int ret;
-
- if (ctx->pwm_value) {
- /* keep ctx->pwm_state unmodified for pwm_fan_resume() */
- struct pwm_state state = ctx->pwm_state;
-
- state.duty_cycle = 0;
- state.enabled = false;
- ret = pwm_apply_state(ctx->pwm, &state);
- if (ret < 0)
- return ret;
- }
-
- ret = pwm_fan_switch_power(ctx, false);
- if (ret) {
- dev_err(dev, "Failed to disable fan supply: %d\n", ret);
- return ret;
- }
-
- return 0;
-}
-
static void pwm_fan_shutdown(struct platform_device *pdev)
{
- pwm_fan_disable(&pdev->dev);
+ struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);
+
+ pwm_fan_cleanup(ctx);
}
#ifdef CONFIG_PM_SLEEP
static int pwm_fan_suspend(struct device *dev)
{
- return pwm_fan_disable(dev);
+ struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
+
+ return pwm_fan_power_off(ctx);
}
static int pwm_fan_resume(struct device *dev)
{
struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
- int ret;
-
- ret = pwm_fan_switch_power(ctx, true);
- if (ret) {
- dev_err(dev, "Failed to enable fan supply: %d\n", ret);
- return ret;
- }
-
- if (ctx->pwm_value == 0)
- return 0;
- return pwm_apply_state(ctx->pwm, &ctx->pwm_state);
+ return set_pwm(ctx, ctx->pwm_value);
}
#endif
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.