hwmon: (lm85) Make the pwmN_enable files writable

Make the pwmN_enable files writable. This makes it possible to use
standard fan speed control tools (pwmconfig, fancontrol) with the lm85
driver.

I left the non-standard pwmN_auto_channels files in place, as they
give additional control for the automatic mode, and some users might
be used to them by now.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>

1 files changed, 38 insertions, 2 deletions

diff --git a/drivers/hwmon/lm85.c b/drivers/hwmon/lm85.c
index 194b8fb52f0e..9f1c6f1ee035 100644
--- a/drivers/hwmon/lm85.c
+++ b/drivers/hwmon/lm85.c
@@ -536,11 +536,47 @@ static ssize_t show_pwm_enable(struct device *dev, struct device_attribute
         return sprintf(buf, "%d\n", enable);
 }
 
+static ssize_t set_pwm_enable(struct device *dev, struct device_attribute
+                *attr, const char *buf, size_t count)
+{
+        int nr = to_sensor_dev_attr(attr)->index;
+        struct i2c_client *client = to_i2c_client(dev);
+        struct lm85_data *data = i2c_get_clientdata(client);
+        long val = simple_strtol(buf, NULL, 10);
+        u8 config;
+
+        switch (val) {
+        case 0:
+                config = 3;
+                break;
+        case 1:
+                config = 7;
+                break;
+        case 2:
+                /* Here we have to choose arbitrarily one of the 5 possible
+                   configurations; I go for the safest */
+                config = 6;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        mutex_lock(&data->update_lock);
+        data->autofan[nr].config = lm85_read_value(client,
+                LM85_REG_AFAN_CONFIG(nr));
+        data->autofan[nr].config = (data->autofan[nr].config & ~0xe0)
+                | (config << 5);
+        lm85_write_value(client, LM85_REG_AFAN_CONFIG(nr),
+                data->autofan[nr].config);
+        mutex_unlock(&data->update_lock);
+        return count;
+}
+
 #define show_pwm_reg(offset)                                            \
 static SENSOR_DEVICE_ATTR(pwm##offset, S_IRUGO | S_IWUSR,               \
                 show_pwm, set_pwm, offset - 1);                         \
-static SENSOR_DEVICE_ATTR(pwm##offset##_enable, S_IRUGO,                \
-                show_pwm_enable, NULL, offset - 1)
+static SENSOR_DEVICE_ATTR(pwm##offset##_enable, S_IRUGO | S_IWUSR,      \
+                show_pwm_enable, set_pwm_enable, offset - 1)
 
 show_pwm_reg(1);
 show_pwm_reg(2);