diff options
Diffstat (limited to 'drivers/hwmon/pwm-fan.c')
| -rw-r--r-- | drivers/hwmon/pwm-fan.c | 169 |
1 files changed, 124 insertions, 45 deletions
diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index 167221c7628a..5fb2745f0226 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -18,6 +18,7 @@ #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> +#include <linux/interrupt.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/of.h> @@ -26,6 +27,7 @@ #include <linux/regulator/consumer.h> #include <linux/sysfs.h> #include <linux/thermal.h> +#include <linux/timer.h> #define MAX_PWM 255 @@ -33,6 +35,14 @@ struct pwm_fan_ctx { struct mutex lock; struct pwm_device *pwm; struct regulator *reg_en; + + int irq; + atomic_t pulses; + unsigned int rpm; + u8 pulses_per_revolution; + ktime_t sample_start; + struct timer_list rpm_timer; + unsigned int pwm_value; unsigned int pwm_fan_state; unsigned int pwm_fan_max_state; @@ -40,6 +50,32 @@ struct pwm_fan_ctx { struct thermal_cooling_device *cdev; }; +/* This handler assumes self resetting edge triggered interrupt. */ +static irqreturn_t pulse_handler(int irq, void *dev_id) +{ + struct pwm_fan_ctx *ctx = dev_id; + + atomic_inc(&ctx->pulses); + + return IRQ_HANDLED; +} + +static void sample_timer(struct timer_list *t) +{ + struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer); + int pulses; + u64 tmp; + + pulses = atomic_read(&ctx->pulses); + atomic_sub(pulses, &ctx->pulses); + tmp = (u64)pulses * ktime_ms_delta(ktime_get(), ctx->sample_start) * 60; + do_div(tmp, ctx->pulses_per_revolution * 1000); + ctx->rpm = tmp; + + ctx->sample_start = ktime_get(); + mod_timer(&ctx->rpm_timer, jiffies + HZ); +} + static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) { unsigned long period; @@ -100,15 +136,45 @@ static ssize_t pwm_show(struct device *dev, struct device_attribute *attr, return sprintf(buf, "%u\n", ctx->pwm_value); } +static ssize_t rpm_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); + + return sprintf(buf, "%u\n", ctx->rpm); +} static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0); +static SENSOR_DEVICE_ATTR_RO(fan1_input, rpm, 0); static struct attribute *pwm_fan_attrs[] = { &sensor_dev_attr_pwm1.dev_attr.attr, + &sensor_dev_attr_fan1_input.dev_attr.attr, NULL, }; -ATTRIBUTE_GROUPS(pwm_fan); +static umode_t pwm_fan_attrs_visible(struct kobject *kobj, struct attribute *a, + int n) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); + + /* Hide fan_input in case no interrupt is available */ + if (n == 1 && ctx->irq <= 0) + return 0; + + return a->mode; +} + +static const struct attribute_group pwm_fan_group = { + .attrs = pwm_fan_attrs, + .is_visible = pwm_fan_attrs_visible, +}; + +static const struct attribute_group *pwm_fan_groups[] = { + &pwm_fan_group, + NULL, +}; /* thermal cooling device callbacks */ static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev, @@ -207,33 +273,51 @@ static int pwm_fan_of_get_cooling_data(struct device *dev, return 0; } +static void pwm_fan_regulator_disable(void *data) +{ + regulator_disable(data); +} + +static void pwm_fan_pwm_disable(void *__ctx) +{ + struct pwm_fan_ctx *ctx = __ctx; + pwm_disable(ctx->pwm); + del_timer_sync(&ctx->rpm_timer); +} + static int pwm_fan_probe(struct platform_device *pdev) { struct thermal_cooling_device *cdev; + struct device *dev = &pdev->dev; struct pwm_fan_ctx *ctx; struct device *hwmon; int ret; struct pwm_state state = { }; + u32 ppr = 2; - ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); + ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL); if (!ctx) return -ENOMEM; mutex_init(&ctx->lock); - ctx->pwm = devm_of_pwm_get(&pdev->dev, pdev->dev.of_node, NULL); + ctx->pwm = devm_of_pwm_get(dev, dev->of_node, NULL); if (IS_ERR(ctx->pwm)) { ret = PTR_ERR(ctx->pwm); if (ret != -EPROBE_DEFER) - dev_err(&pdev->dev, "Could not get PWM: %d\n", ret); + dev_err(dev, "Could not get PWM: %d\n", ret); return ret; } platform_set_drvdata(pdev, ctx); - ctx->reg_en = devm_regulator_get_optional(&pdev->dev, "fan"); + ctx->irq = platform_get_irq(pdev, 0); + if (ctx->irq == -EPROBE_DEFER) + return ctx->irq; + + ctx->reg_en = devm_regulator_get_optional(dev, "fan"); if (IS_ERR(ctx->reg_en)) { if (PTR_ERR(ctx->reg_en) != -ENODEV) return PTR_ERR(ctx->reg_en); @@ -242,10 +326,11 @@ static int pwm_fan_probe(struct platform_device *pdev) } else { ret = regulator_enable(ctx->reg_en); if (ret) { - dev_err(&pdev->dev, - "Failed to enable fan supply: %d\n", ret); + dev_err(dev, "Failed to enable fan supply: %d\n", ret); return ret; } + devm_add_action_or_reset(dev, pwm_fan_regulator_disable, + ctx->reg_en); } ctx->pwm_value = MAX_PWM; @@ -257,62 +342,57 @@ static int pwm_fan_probe(struct platform_device *pdev) ret = pwm_apply_state(ctx->pwm, &state); if (ret) { - dev_err(&pdev->dev, "Failed to configure PWM\n"); - goto err_reg_disable; + dev_err(dev, "Failed to configure PWM: %d\n", ret); + return ret; + } + timer_setup(&ctx->rpm_timer, sample_timer, 0); + devm_add_action_or_reset(dev, pwm_fan_pwm_disable, ctx); + + of_property_read_u32(dev->of_node, "pulses-per-revolution", &ppr); + ctx->pulses_per_revolution = ppr; + if (!ctx->pulses_per_revolution) { + dev_err(dev, "pulses-per-revolution can't be zero.\n"); + return -EINVAL; + } + + if (ctx->irq > 0) { + ret = devm_request_irq(dev, ctx->irq, pulse_handler, 0, + pdev->name, ctx); + if (ret) { + dev_err(dev, "Failed to request interrupt: %d\n", ret); + return ret; + } + ctx->sample_start = ktime_get(); + mod_timer(&ctx->rpm_timer, jiffies + HZ); } - hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan", + hwmon = devm_hwmon_device_register_with_groups(dev, "pwmfan", ctx, pwm_fan_groups); if (IS_ERR(hwmon)) { - dev_err(&pdev->dev, "Failed to register hwmon device\n"); - ret = PTR_ERR(hwmon); - goto err_pwm_disable; + dev_err(dev, "Failed to register hwmon device\n"); + return PTR_ERR(hwmon); } - ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx); + ret = pwm_fan_of_get_cooling_data(dev, ctx); if (ret) return ret; ctx->pwm_fan_state = ctx->pwm_fan_max_state; if (IS_ENABLED(CONFIG_THERMAL)) { - cdev = thermal_of_cooling_device_register(pdev->dev.of_node, - "pwm-fan", ctx, - &pwm_fan_cooling_ops); + cdev = devm_thermal_of_cooling_device_register(dev, + dev->of_node, "pwm-fan", ctx, &pwm_fan_cooling_ops); if (IS_ERR(cdev)) { - dev_err(&pdev->dev, - "Failed to register pwm-fan as cooling device"); ret = PTR_ERR(cdev); - goto err_pwm_disable; + dev_err(dev, + "Failed to register pwm-fan as cooling device: %d\n", + ret); + return ret; } ctx->cdev = cdev; thermal_cdev_update(cdev); } return 0; - -err_pwm_disable: - state.enabled = false; - pwm_apply_state(ctx->pwm, &state); - -err_reg_disable: - if (ctx->reg_en) - regulator_disable(ctx->reg_en); - - return ret; -} - -static int pwm_fan_remove(struct platform_device *pdev) -{ - struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev); - - thermal_cooling_device_unregister(ctx->cdev); - if (ctx->pwm_value) - pwm_disable(ctx->pwm); - - if (ctx->reg_en) - regulator_disable(ctx->reg_en); - - return 0; } #ifdef CONFIG_PM_SLEEP @@ -380,7 +460,6 @@ MODULE_DEVICE_TABLE(of, of_pwm_fan_match); static struct platform_driver pwm_fan_driver = { .probe = pwm_fan_probe, - .remove = pwm_fan_remove, .driver = { .name = "pwm-fan", .pm = &pwm_fan_pm, |