diff options
| -rw-r--r-- | Documentation/hwmon/pwm-fan.rst | 12 | ||||
| -rw-r--r-- | drivers/hwmon/pwm-fan.c | 210 |
2 files changed, 154 insertions, 68 deletions
diff --git a/Documentation/hwmon/pwm-fan.rst b/Documentation/hwmon/pwm-fan.rst index 82fe96742fee..f77998b204ef 100644 --- a/Documentation/hwmon/pwm-fan.rst +++ b/Documentation/hwmon/pwm-fan.rst @@ -18,3 +18,15 @@ the hwmon's sysfs interface. The fan rotation speed returned via the optional 'fan1_input' is extrapolated from the sampled interrupts from the tachometer signal within 1 second. + +The driver provides the following sensor accesses in sysfs: + +=============== ======= ======================================================= +fan1_input ro fan tachometer speed in RPM +pwm1_enable rw keep enable mode, defines behaviour when pwm1=0 + 0 -> disable pwm and regulator + 1 -> enable pwm; if pwm==0, disable pwm, keep regulator enabled + 2 -> enable pwm; if pwm==0, keep pwm and regulator enabled + 3 -> enable pwm; if pwm==0, disable pwm and regulator +pwm1 rw relative speed (0-255), 255=max. speed. +=============== ======= ======================================================= 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 |