hwmon/f71805f: Let the user adjust the PWM base frequency

Different frequencies can give better results depending on the exact fan
model used.

Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 62 insertions, 1 deletions

diff --git a/drivers/hwmon/f71805f.c b/drivers/hwmon/f71805f.c
index 6e6542036c6a..173e2d2cb49c 100644
--- a/drivers/hwmon/f71805f.c
+++ b/drivers/hwmon/f71805f.c
@@ -112,6 +112,7 @@ superio_exit(int base)
 #define F71805F_REG_FAN(nr)             (0x20 + 2 * (nr))
 #define F71805F_REG_FAN_LOW(nr)         (0x28 + 2 * (nr))
 #define F71805F_REG_FAN_CTRL(nr)        (0x60 + 16 * (nr))
+#define F71805F_REG_PWM_FREQ(nr)        (0x63 + 16 * (nr))
 #define F71805F_REG_PWM_DUTY(nr)        (0x6B + 16 * (nr))
 /* temp nr from 0 to 2 (8-bit values) */
 #define F71805F_REG_TEMP(nr)            (0x1B + (nr))
@@ -153,6 +154,7 @@ struct f71805f_data {
         u16 fan_low[3];
         u8 fan_ctrl[3];
         u8 pwm[3];
+        u8 pwm_freq[3];
         u8 temp[3];
         u8 temp_high[3];
         u8 temp_hyst[3];
@@ -209,6 +211,28 @@ static inline u16 fan_to_reg(long rpm)
         return (1500000 / rpm);
 }
 
+static inline unsigned long pwm_freq_from_reg(u8 reg)
+{
+        unsigned long clock = (reg & 0x80) ? 48000000UL : 1000000UL;
+
+        reg &= 0x7f;
+        if (reg == 0)
+                reg++;
+        return clock / (reg << 8);
+}
+
+static inline u8 pwm_freq_to_reg(unsigned long val)
+{
+        if (val >= 187500)      /* The highest we can do */
+                return 0x80;
+        if (val >= 1475)        /* Use 48 MHz clock */
+                return 0x80 | (48000000UL / (val << 8));
+        if (val < 31)           /* The lowest we can do */
+                return 0x7f;
+        else                    /* Use 1 MHz clock */
+                return 1000000UL / (val << 8);
+}
+
 static inline long temp_from_reg(u8 reg)
 {
         return (reg * 1000);
@@ -294,6 +318,8 @@ static struct f71805f_data *f71805f_update_device(struct device *dev)
                                 continue;
                         data->fan_low[nr] = f71805f_read16(data,
                                             F71805F_REG_FAN_LOW(nr));
+                        data->pwm_freq[nr] = f71805f_read8(data,
+                                             F71805F_REG_PWM_FREQ(nr));
                 }
                 for (nr = 0; nr < 3; nr++) {
                         data->temp_high[nr] = f71805f_read8(data,
@@ -526,6 +552,16 @@ static ssize_t show_pwm_enable(struct device *dev, struct device_attribute
         return sprintf(buf, "%d\n", mode);
 }
 
+static ssize_t show_pwm_freq(struct device *dev, struct device_attribute
+                             *devattr, char *buf)
+{
+        struct f71805f_data *data = f71805f_update_device(dev);
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        int nr = attr->index;
+
+        return sprintf(buf, "%lu\n", pwm_freq_from_reg(data->pwm_freq[nr]));
+}
+
 static ssize_t set_pwm(struct device *dev, struct device_attribute *devattr,
                        const char *buf, size_t count)
 {
@@ -592,6 +628,22 @@ static ssize_t set_pwm_enable(struct device *dev, struct device_attribute
         return count;
 }
 
+static ssize_t set_pwm_freq(struct device *dev, struct device_attribute
+                            *devattr, const char *buf, size_t count)
+{
+        struct f71805f_data *data = dev_get_drvdata(dev);
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        int nr = attr->index;
+        unsigned long val = simple_strtoul(buf, NULL, 10);
+
+        mutex_lock(&data->update_lock);
+        data->pwm_freq[nr] = pwm_freq_to_reg(val);
+        f71805f_write8(data, F71805F_REG_PWM_FREQ(nr), data->pwm_freq[nr]);
+        mutex_unlock(&data->update_lock);
+
+        return count;
+}
+
 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
                          char *buf)
 {
@@ -785,12 +837,18 @@ static SENSOR_DEVICE_ATTR(temp3_type, S_IRUGO, show_temp_type, NULL, 2);
 static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO, show_pwm, set_pwm, 0);
 static SENSOR_DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR,
                           show_pwm_enable, set_pwm_enable, 0);
+static SENSOR_DEVICE_ATTR(pwm1_freq, S_IRUGO | S_IWUSR,
+                          show_pwm_freq, set_pwm_freq, 0);
 static SENSOR_DEVICE_ATTR(pwm2, S_IRUGO, show_pwm, set_pwm, 1);
 static SENSOR_DEVICE_ATTR(pwm2_enable, S_IRUGO | S_IWUSR,
                           show_pwm_enable, set_pwm_enable, 1);
+static SENSOR_DEVICE_ATTR(pwm2_freq, S_IRUGO | S_IWUSR,
+                          show_pwm_freq, set_pwm_freq, 1);
 static SENSOR_DEVICE_ATTR(pwm3, S_IRUGO, show_pwm, set_pwm, 2);
 static SENSOR_DEVICE_ATTR(pwm3_enable, S_IRUGO | S_IWUSR,
                           show_pwm_enable, set_pwm_enable, 2);
+static SENSOR_DEVICE_ATTR(pwm3_freq, S_IRUGO | S_IWUSR,
+                          show_pwm_freq, set_pwm_freq, 2);
 
 static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, show_alarm, NULL, 0);
 static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, show_alarm, NULL, 1);
@@ -879,13 +937,14 @@ static const struct attribute_group f71805f_group = {
         .attrs = f71805f_attributes,
 };
 
-static struct attribute *f71805f_attributes_fan[3][6] = {
+static struct attribute *f71805f_attributes_fan[3][7] = {
         {
                 &sensor_dev_attr_fan1_input.dev_attr.attr,
                 &sensor_dev_attr_fan1_min.dev_attr.attr,
                 &sensor_dev_attr_fan1_alarm.dev_attr.attr,
                 &sensor_dev_attr_pwm1.dev_attr.attr,
                 &sensor_dev_attr_pwm1_enable.dev_attr.attr,
+                &sensor_dev_attr_pwm1_freq.dev_attr.attr,
                 NULL
         }, {
                 &sensor_dev_attr_fan2_input.dev_attr.attr,
@@ -893,6 +952,7 @@ static struct attribute *f71805f_attributes_fan[3][6] = {
                 &sensor_dev_attr_fan2_alarm.dev_attr.attr,
                 &sensor_dev_attr_pwm2.dev_attr.attr,
                 &sensor_dev_attr_pwm2_enable.dev_attr.attr,
+                &sensor_dev_attr_pwm2_freq.dev_attr.attr,
                 NULL
         }, {
                 &sensor_dev_attr_fan3_input.dev_attr.attr,
@@ -900,6 +960,7 @@ static struct attribute *f71805f_attributes_fan[3][6] = {
                 &sensor_dev_attr_fan3_alarm.dev_attr.attr,
                 &sensor_dev_attr_pwm3.dev_attr.attr,
                 &sensor_dev_attr_pwm3_enable.dev_attr.attr,
+                &sensor_dev_attr_pwm3_freq.dev_attr.attr,
                 NULL
         }
 };