From cb85ca332f4d72ca68464c55f63af0387f6bbdb1 Mon Sep 17 00:00:00 2001 From: Lukasz Majewski Date: Thu, 26 Feb 2015 14:59:35 +0100 Subject: hwmon: (pwm-fan) Extract __set_pwm() function to only modify PWM duty cycle It was necessary to decouple code handling writing to sysfs from the one responsible for setting PWM of the fan. Due to that, new __set_pwm() method was extracted, which is responsible for only setting new PWM duty cycle. Signed-off-by: Lukasz Majewski Signed-off-by: Guenter Roeck --- drivers/hwmon/pwm-fan.c | 33 +++++++++++++++++++++------------ 1 file changed, 21 insertions(+), 12 deletions(-) (limited to 'drivers/hwmon/pwm-fan.c') diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index 1991d9032c38..bd42d3996a86 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -33,20 +33,14 @@ struct pwm_fan_ctx { unsigned char pwm_value; }; -static ssize_t set_pwm(struct device *dev, struct device_attribute *attr, - const char *buf, size_t count) +static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) { - struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); - unsigned long pwm, duty; - ssize_t ret; - - if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM) - return -EINVAL; + unsigned long duty; + int ret = 0; mutex_lock(&ctx->lock); - if (ctx->pwm_value == pwm) - goto exit_set_pwm_no_change; + goto exit_set_pwm_err; if (pwm == 0) { pwm_disable(ctx->pwm); @@ -66,13 +60,28 @@ static ssize_t set_pwm(struct device *dev, struct device_attribute *attr, exit_set_pwm: ctx->pwm_value = pwm; -exit_set_pwm_no_change: - ret = count; exit_set_pwm_err: mutex_unlock(&ctx->lock); return ret; } +static ssize_t set_pwm(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); + unsigned long pwm; + int ret; + + if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM) + return -EINVAL; + + ret = __set_pwm(ctx, pwm); + if (ret) + return ret; + + return count; +} + static ssize_t show_pwm(struct device *dev, struct device_attribute *attr, char *buf) { -- cgit v1.2.3 From 2e5219c77183be47eb9ae4b1a4195e008d196c73 Mon Sep 17 00:00:00 2001 From: Lukasz Majewski Date: Thu, 26 Feb 2015 14:59:36 +0100 Subject: hwmon: (pwm-fan) Read PWM FAN configuration from device tree This patch provides code for reading PWM FAN configuration data via device tree. The pwm-fan can work with full speed when configuration is not provided. However, errors are propagated when wrong DT bindings are found. Additionally the struct pwm_fan_ctx has been extended. Signed-off-by: Lukasz Majewski Signed-off-by: Guenter Roeck --- drivers/hwmon/pwm-fan.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 49 insertions(+), 1 deletion(-) (limited to 'drivers/hwmon/pwm-fan.c') diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index bd42d3996a86..e6ed3532deac 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -30,7 +30,10 @@ struct pwm_fan_ctx { struct mutex lock; struct pwm_device *pwm; - unsigned char pwm_value; + unsigned int pwm_value; + unsigned int pwm_fan_state; + unsigned int pwm_fan_max_state; + unsigned int *pwm_fan_cooling_levels; }; static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) @@ -100,6 +103,46 @@ static struct attribute *pwm_fan_attrs[] = { ATTRIBUTE_GROUPS(pwm_fan); +int pwm_fan_of_get_cooling_data(struct device *dev, struct pwm_fan_ctx *ctx) +{ + struct device_node *np = dev->of_node; + int num, i, ret; + + if (!of_find_property(np, "cooling-levels", NULL)) + return 0; + + ret = of_property_count_u32_elems(np, "cooling-levels"); + if (ret <= 0) { + dev_err(dev, "Wrong data!\n"); + return ret ? : -EINVAL; + } + + num = ret; + ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, num * sizeof(u32), + GFP_KERNEL); + if (!ctx->pwm_fan_cooling_levels) + return -ENOMEM; + + ret = of_property_read_u32_array(np, "cooling-levels", + ctx->pwm_fan_cooling_levels, num); + if (ret) { + dev_err(dev, "Property 'cooling-levels' cannot be read!\n"); + return ret; + } + + for (i = 0; i < num; i++) { + if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) { + dev_err(dev, "PWM fan state[%d]:%d > %d\n", i, + ctx->pwm_fan_cooling_levels[i], MAX_PWM); + return -EINVAL; + } + } + + ctx->pwm_fan_max_state = num - 1; + + return 0; +} + static int pwm_fan_probe(struct platform_device *pdev) { struct device *hwmon; @@ -145,6 +188,11 @@ static int pwm_fan_probe(struct platform_device *pdev) pwm_disable(ctx->pwm); return PTR_ERR(hwmon); } + + ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx); + if (ret) + return ret; + return 0; } -- cgit v1.2.3 From b6bddec01932b94a20b6a7bbb7ed9d98e82ec162 Mon Sep 17 00:00:00 2001 From: Lukasz Majewski Date: Thu, 26 Feb 2015 14:59:37 +0100 Subject: hwmon: (pwm-fan) Add support for using PWM FAN as a cooling device The PWM FAN device can now be used as a thermal cooling device. Signed-off-by: Lukasz Majewski Acked-by: Eduardo Valentin Signed-off-by: Guenter Roeck --- drivers/hwmon/pwm-fan.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 88 insertions(+), 1 deletion(-) (limited to 'drivers/hwmon/pwm-fan.c') diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index e6ed3532deac..7c83dc4c8dbd 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -24,6 +24,7 @@ #include #include #include +#include #define MAX_PWM 255 @@ -34,6 +35,7 @@ struct pwm_fan_ctx { unsigned int pwm_fan_state; unsigned int pwm_fan_max_state; unsigned int *pwm_fan_cooling_levels; + struct thermal_cooling_device *cdev; }; static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) @@ -68,6 +70,17 @@ exit_set_pwm_err: return ret; } +static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm) +{ + int i; + + for (i = 0; i < ctx->pwm_fan_max_state; ++i) + if (pwm < ctx->pwm_fan_cooling_levels[i + 1]) + break; + + ctx->pwm_fan_state = i; +} + static ssize_t set_pwm(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { @@ -82,6 +95,7 @@ static ssize_t set_pwm(struct device *dev, struct device_attribute *attr, if (ret) return ret; + pwm_fan_update_state(ctx, pwm); return count; } @@ -103,6 +117,62 @@ static struct attribute *pwm_fan_attrs[] = { ATTRIBUTE_GROUPS(pwm_fan); +/* thermal cooling device callbacks */ +static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev, + unsigned long *state) +{ + struct pwm_fan_ctx *ctx = cdev->devdata; + + if (!ctx) + return -EINVAL; + + *state = ctx->pwm_fan_max_state; + + return 0; +} + +static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev, + unsigned long *state) +{ + struct pwm_fan_ctx *ctx = cdev->devdata; + + if (!ctx) + return -EINVAL; + + *state = ctx->pwm_fan_state; + + return 0; +} + +static int +pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state) +{ + struct pwm_fan_ctx *ctx = cdev->devdata; + int ret; + + if (!ctx || (state > ctx->pwm_fan_max_state)) + return -EINVAL; + + if (state == ctx->pwm_fan_state) + return 0; + + ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]); + if (ret) { + dev_err(&cdev->device, "Cannot set pwm!\n"); + return ret; + } + + ctx->pwm_fan_state = state; + + return ret; +} + +static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = { + .get_max_state = pwm_fan_get_max_state, + .get_cur_state = pwm_fan_get_cur_state, + .set_cur_state = pwm_fan_set_cur_state, +}; + int pwm_fan_of_get_cooling_data(struct device *dev, struct pwm_fan_ctx *ctx) { struct device_node *np = dev->of_node; @@ -145,8 +215,9 @@ int pwm_fan_of_get_cooling_data(struct device *dev, struct pwm_fan_ctx *ctx) static int pwm_fan_probe(struct platform_device *pdev) { - struct device *hwmon; + struct thermal_cooling_device *cdev; struct pwm_fan_ctx *ctx; + struct device *hwmon; int duty_cycle; int ret; @@ -193,6 +264,21 @@ static int pwm_fan_probe(struct platform_device *pdev) 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); + if (IS_ERR(cdev)) { + dev_err(&pdev->dev, + "Failed to register pwm-fan as cooling device"); + pwm_disable(ctx->pwm); + return PTR_ERR(cdev); + } + ctx->cdev = cdev; + thermal_cdev_update(cdev); + } + return 0; } @@ -200,6 +286,7 @@ 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); return 0; -- cgit v1.2.3 From de52b049d6d5af635d628d17fcb466d53a9617af Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Wed, 4 Mar 2015 09:51:05 -0800 Subject: hwmon: (pwm-fan) Declare pwm_fan_of_get_cooling_data static Address the following sparse warnings. drivers/hwmon/pwm-fan.c:176:5: warning: symbol 'pwm_fan_of_get_cooling_data' was not declared. Should it be static? drivers/hwmon/pwm-fan.c:176:5: warning: no previous prototype for 'pwm_fan_of_get_cooling_data' pwm_fan_of_get_cooling_data is only used in the pwm-fan driver and thus should be declared static. Cc: Lukasz Majewski Acked-by: Lukasz Majewski Signed-off-by: Guenter Roeck --- drivers/hwmon/pwm-fan.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/hwmon/pwm-fan.c') diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index 7c83dc4c8dbd..417072863ebe 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -173,7 +173,8 @@ static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = { .set_cur_state = pwm_fan_set_cur_state, }; -int pwm_fan_of_get_cooling_data(struct device *dev, struct pwm_fan_ctx *ctx) +static int pwm_fan_of_get_cooling_data(struct device *dev, + struct pwm_fan_ctx *ctx) { struct device_node *np = dev->of_node; int num, i, ret; -- cgit v1.2.3 From d720acace4d7989f0d5617868e8277221e882961 Mon Sep 17 00:00:00 2001 From: Fabian Frederick Date: Mon, 16 Mar 2015 20:54:36 +0100 Subject: hwmon: (pwm-fan, vexpress) Constify of_device_id array of_device_id is always used as const. (See driver.of_match_table and open firmware functions) Signed-off-by: Fabian Frederick Signed-off-by: Guenter Roeck --- drivers/hwmon/pwm-fan.c | 2 +- drivers/hwmon/vexpress.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/hwmon/pwm-fan.c') diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index 417072863ebe..31d793bd7b12 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -322,7 +322,7 @@ static int pwm_fan_resume(struct device *dev) static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume); -static struct of_device_id of_pwm_fan_match[] = { +static const struct of_device_id of_pwm_fan_match[] = { { .compatible = "pwm-fan", }, {}, }; diff --git a/drivers/hwmon/vexpress.c b/drivers/hwmon/vexpress.c index cf1848b8fb32..8ba419d343f8 100644 --- a/drivers/hwmon/vexpress.c +++ b/drivers/hwmon/vexpress.c @@ -193,7 +193,7 @@ static struct vexpress_hwmon_type vexpress_hwmon_energy = { }, }; -static struct of_device_id vexpress_hwmon_of_match[] = { +static const struct of_device_id vexpress_hwmon_of_match[] = { #if !defined(CONFIG_REGULATOR_VEXPRESS) { .compatible = "arm,vexpress-volt", -- cgit v1.2.3 From f354169e0f7dcd1b2c82cf1f98f6d976e85f74c3 Mon Sep 17 00:00:00 2001 From: Anand Moon Date: Mon, 13 Apr 2015 04:14:11 +0930 Subject: hwmon: (pwm-fan) Update the duty cycle inorder to control the pwm-fan pwm_config() must be called with a duty cycle of 0 prior to calling pwm_disable() to ensure that the pwm signal is set to low. Reported-by: Markus Reichl Tested-by: Markus Reichl Reviewed-by: Lukasz Majewski Reviewed-by: Sjoerd Simons Signed-off-by: Anand Moon Signed-off-by: Guenter Roeck --- drivers/hwmon/pwm-fan.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'drivers/hwmon/pwm-fan.c') diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index 31d793bd7b12..2d9a712699ff 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -47,23 +47,20 @@ static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) if (ctx->pwm_value == pwm) goto exit_set_pwm_err; - if (pwm == 0) { - pwm_disable(ctx->pwm); - goto exit_set_pwm; - } - duty = DIV_ROUND_UP(pwm * (ctx->pwm->period - 1), MAX_PWM); ret = pwm_config(ctx->pwm, duty, ctx->pwm->period); if (ret) goto exit_set_pwm_err; + if (pwm == 0) + pwm_disable(ctx->pwm); + if (ctx->pwm_value == 0) { ret = pwm_enable(ctx->pwm); if (ret) goto exit_set_pwm_err; } -exit_set_pwm: ctx->pwm_value = pwm; exit_set_pwm_err: mutex_unlock(&ctx->lock); -- cgit v1.2.3