diff options
Diffstat (limited to 'drivers/hwmon/pwm-fan.c')
| -rw-r--r-- | drivers/hwmon/pwm-fan.c | 84 |
1 files changed, 67 insertions, 17 deletions
diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index a1712649b07e..37269db2de84 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -7,6 +7,7 @@ * Author: Kamil Debski <k.debski@samsung.com> */ +#include <linux/delay.h> #include <linux/hwmon.h> #include <linux/interrupt.h> #include <linux/mod_devicetable.h> @@ -60,6 +61,10 @@ struct pwm_fan_ctx { struct hwmon_chip_info info; struct hwmon_channel_info fan_channel; + + u64 pwm_duty_cycle_from_stopped; + u32 pwm_usec_from_stopped; + u8 pwm_shutdown; }; /* This handler assumes self resetting edge triggered interrupt. */ @@ -74,7 +79,7 @@ static irqreturn_t pulse_handler(int irq, void *dev_id) static void sample_timer(struct timer_list *t) { - struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer); + struct pwm_fan_ctx *ctx = timer_container_of(ctx, t, rpm_timer); unsigned int delta = ktime_ms_delta(ktime_get(), ctx->sample_start); int i; @@ -167,7 +172,7 @@ disable_regulator: return ret; } -static int pwm_fan_power_off(struct pwm_fan_ctx *ctx) +static int pwm_fan_power_off(struct pwm_fan_ctx *ctx, bool force_disable) { struct pwm_state *state = &ctx->pwm_state; bool enable_regulator = false; @@ -180,7 +185,8 @@ static int pwm_fan_power_off(struct pwm_fan_ctx *ctx) state, &enable_regulator); - state->enabled = false; + if (force_disable) + state->enabled = false; state->duty_cycle = 0; ret = pwm_apply_might_sleep(ctx->pwm, state); if (ret) { @@ -198,7 +204,9 @@ static int pwm_fan_power_off(struct pwm_fan_ctx *ctx) static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) { struct pwm_state *state = &ctx->pwm_state; + unsigned long final_pwm = pwm; unsigned long period; + bool update = false; int ret = 0; if (pwm > 0) { @@ -207,13 +215,24 @@ static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) return 0; period = state->period; - state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); + update = state->duty_cycle < ctx->pwm_duty_cycle_from_stopped; + if (update) + state->duty_cycle = ctx->pwm_duty_cycle_from_stopped; + else + state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); ret = pwm_apply_might_sleep(ctx->pwm, state); if (ret) return ret; ret = pwm_fan_power_on(ctx); + if (!ret && update) { + pwm = final_pwm; + state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); + usleep_range(ctx->pwm_usec_from_stopped, + ctx->pwm_usec_from_stopped * 2); + ret = pwm_apply_might_sleep(ctx->pwm, state); + } } else { - ret = pwm_fan_power_off(ctx); + ret = pwm_fan_power_off(ctx, false); } if (!ret) ctx->pwm_value = pwm; @@ -465,10 +484,15 @@ static void pwm_fan_cleanup(void *__ctx) { struct pwm_fan_ctx *ctx = __ctx; - del_timer_sync(&ctx->rpm_timer); - /* Switch off everything */ - ctx->enable_mode = pwm_disable_reg_disable; - pwm_fan_power_off(ctx); + timer_delete_sync(&ctx->rpm_timer); + if (ctx->pwm_shutdown) { + ctx->enable_mode = pwm_enable_reg_enable; + __set_pwm(ctx, ctx->pwm_shutdown); + } else { + /* Switch off everything */ + ctx->enable_mode = pwm_disable_reg_disable; + pwm_fan_power_off(ctx, true); + } } static int pwm_fan_probe(struct platform_device *pdev) @@ -479,6 +503,8 @@ static int pwm_fan_probe(struct platform_device *pdev) struct device *hwmon; int ret; const struct hwmon_channel_info **channels; + u32 initial_pwm, pwm_min_from_stopped = 0; + u32 pwm_shutdown_percent = 0; u32 *fan_channel_config; int channel_count = 1; /* We always have a PWM channel. */ int i; @@ -526,11 +552,21 @@ static int pwm_fan_probe(struct platform_device *pdev) ctx->enable_mode = pwm_disable_reg_enable; + ret = pwm_fan_get_cooling_data(dev, ctx); + if (ret) + return ret; + + /* use maximum cooling level if provided */ + if (ctx->pwm_fan_cooling_levels) + initial_pwm = ctx->pwm_fan_cooling_levels[ctx->pwm_fan_max_state]; + else + initial_pwm = MAX_PWM; + /* * 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); + ret = set_pwm(ctx, initial_pwm); if (ret) { dev_err(dev, "Failed to configure PWM: %d\n", ret); return ret; @@ -591,8 +627,8 @@ static int pwm_fan_probe(struct platform_device *pdev) if (tach->irq == -EPROBE_DEFER) return tach->irq; if (tach->irq > 0) { - ret = devm_request_irq(dev, tach->irq, pulse_handler, 0, - pdev->name, tach); + ret = devm_request_irq(dev, tach->irq, pulse_handler, + IRQF_NO_THREAD, pdev->name, tach); if (ret) { dev_err(dev, "Failed to request interrupt: %d\n", @@ -619,6 +655,24 @@ static int pwm_fan_probe(struct platform_device *pdev) channels[1] = &ctx->fan_channel; } + ret = device_property_read_u32(dev, "fan-shutdown-percent", + &pwm_shutdown_percent); + if (!ret && pwm_shutdown_percent) + ctx->pwm_shutdown = (clamp(pwm_shutdown_percent, 0, 100) * 255) / 100; + + ret = device_property_read_u32(dev, "fan-stop-to-start-percent", + &pwm_min_from_stopped); + if (!ret && pwm_min_from_stopped) { + ctx->pwm_duty_cycle_from_stopped = + DIV_ROUND_UP_ULL(pwm_min_from_stopped * + (ctx->pwm_state.period - 1), + 100); + } + ret = device_property_read_u32(dev, "fan-stop-to-start-us", + &ctx->pwm_usec_from_stopped); + if (ret) + ctx->pwm_usec_from_stopped = 250000; + ctx->info.ops = &pwm_fan_hwmon_ops; ctx->info.info = channels; @@ -629,10 +683,6 @@ static int pwm_fan_probe(struct platform_device *pdev) return PTR_ERR(hwmon); } - ret = pwm_fan_get_cooling_data(dev, ctx); - if (ret) - return ret; - ctx->pwm_fan_state = ctx->pwm_fan_max_state; if (IS_ENABLED(CONFIG_THERMAL)) { cdev = devm_thermal_of_cooling_device_register(dev, @@ -661,7 +711,7 @@ static int pwm_fan_suspend(struct device *dev) { struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); - return pwm_fan_power_off(ctx); + return pwm_fan_power_off(ctx, true); } static int pwm_fan_resume(struct device *dev) |