From 2e5219c77183be47eb9ae4b1a4195e008d196c73 Mon Sep 17 00:00:00 2001 From: Lukasz Majewski Date: Thu, 26 Feb 2015 14:59:36 +0100 Subject: [PATCH] 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(-) diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index bd42d39..e6ed353 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; } -- 2.7.4