diff options
| author | Lukasz Majewski <l.majewski@samsung.com> | 2015-02-26 14:59:36 +0100 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2015-03-09 17:59:36 +0100 |
| commit | 2e5219c77183be47eb9ae4b1a4195e008d196c73 (patch) | |
| tree | e4401ed00f312bb3a6ee8ce188c89b1b46b5bfd5 /drivers/hwmon | |
| parent | hwmon: (pwm-fan) Extract __set_pwm() function to only modify PWM duty cycle (diff) | |
| download | linux-2e5219c77183be47eb9ae4b1a4195e008d196c73.tar.xz linux-2e5219c77183be47eb9ae4b1a4195e008d196c73.zip | |
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 <l.majewski@samsung.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
| -rw-r--r-- | drivers/hwmon/pwm-fan.c | 50 |
1 files changed, 49 insertions, 1 deletions
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; } |