[lm-sensors] [PATCH] Fix the set pwm value will change fan mode bug

[ymu@Winbond.com.tw (Yuan Mu)]

Hi Jean,

W83792D use pwm register low 4 bits to store fan PWM/DC value, bit 7 is used to store fan PWM/DC mode,
The store_pwm function use a wrong limit 0-255, so it may change the fan mode when set value is large than 127.

This fix the problem. Change the "index" value of pwm*_mode and pwm* SENSOR_ATTR to simplify code.

Signed-off-by: Yuan Mu <ymu at winbond.com.tw>
---
  w83792d.c |   59 +++++++++++++++++++++++++++--------------------------------
  1 file changed, 27 insertions(+), 32 deletions(-)

--- linux-2.6.17-rc2.orig/drivers/hwmon/w83792d.c	2006-04-19 18:04:04.000000000 +0800
+++ linux-2.6.17-rc2/drivers/hwmon/w83792d.c	2006-04-19 18:07:05.000000000 +0800
@@ -250,8 +250,6 @@ FAN_TO_REG(long rpm, int div)
  			: (val)) / 1000, 0, 0xff))
  #define TEMP_ADD_TO_REG_LOW(val)	((val%1000) ? 0x80 : 0x00)

-#define PWM_FROM_REG(val)		(val)
-#define PWM_TO_REG(val)			(SENSORS_LIMIT((val),0,255))
  #define DIV_FROM_REG(val)		(1 << (val))

  static inline u8
@@ -288,10 +286,8 @@ struct w83792d_data {
  	u8 temp1[3];		/* current, over, thyst */
  	u8 temp_add[2][6];	/* Register value */
  	u8 fan_div[7];		/* Register encoding, shifted right */
-	u8 pwm[7];		/* We only consider the first 3 set of pwm,
-				   although 792 chip has 7 set of pwm. */
+	u8 pwm[7];		/* Register value */
  	u8 pwmenable[3];
-	u8 pwm_mode[7];		/* indicates PWM or DC mode: 1->PWM; 0->DC */
  	u32 alarms;		/* realtime status register encoding,combined */
  	u8 chassis;		/* Chassis status */
  	u8 chassis_clear;	/* CLR_CHS, clear chassis intrusion detection */
@@ -627,7 +623,8 @@ show_pwm(struct device *dev, struct devi
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct w83792d_data *data = w83792d_update_device(dev);
-	return sprintf(buf, "%ld\n", (long) PWM_FROM_REG(data->pwm[nr-1]));
+
+	return sprintf(buf, "%d\n", data->pwm[nr] & 0x0f);
  }

  static ssize_t
@@ -659,14 +656,16 @@ store_pwm(struct device *dev, struct dev
  		const char *buf, size_t count)
  {
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
-	int nr = sensor_attr->index - 1;
+	int nr = sensor_attr->index;
  	struct i2c_client *client = to_i2c_client(dev);
  	struct w83792d_data *data = i2c_get_clientdata(client);
-	u32 val;
+	u8 val = data->pwm[nr] & 0xf0;

-	val = simple_strtoul(buf, NULL, 10);
-	data->pwm[nr] = PWM_TO_REG(val);
-	w83792d_write_value(client, W83792D_REG_PWM[nr], data->pwm[nr]);
+	val |= SENSORS_LIMIT(simple_strtoul(buf, NULL, 10), 0, 0x0f);
+	if (val != data->pwm[nr]) {
+		data->pwm[nr] = val;
+		w83792d_write_value(client, W83792D_REG_PWM[nr], val);
+	}

  	return count;
  }
@@ -707,9 +706,9 @@ store_pwmenable(struct device *dev, stru
  }

  static struct sensor_device_attribute sda_pwm[] = {
-	SENSOR_ATTR(pwm1, S_IWUSR | S_IRUGO, show_pwm, store_pwm, 1),
-	SENSOR_ATTR(pwm2, S_IWUSR | S_IRUGO, show_pwm, store_pwm, 2),
-	SENSOR_ATTR(pwm3, S_IWUSR | S_IRUGO, show_pwm, store_pwm, 3),
+	SENSOR_ATTR(pwm1, S_IWUSR | S_IRUGO, show_pwm, store_pwm, 0),
+	SENSOR_ATTR(pwm2, S_IWUSR | S_IRUGO, show_pwm, store_pwm, 1),
+	SENSOR_ATTR(pwm3, S_IWUSR | S_IRUGO, show_pwm, store_pwm, 2),
  };
  static struct sensor_device_attribute sda_pwm_enable[] = {
  	SENSOR_ATTR(pwm1_enable, S_IWUSR | S_IRUGO,
@@ -728,7 +727,7 @@ show_pwm_mode(struct device *dev, struct
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct w83792d_data *data = w83792d_update_device(dev);
-	return sprintf(buf, "%d\n", data->pwm_mode[nr-1]);
+	return sprintf(buf, "%d\n", data->pwm[nr] >> 7);
  }

  static ssize_t
@@ -736,29 +735,28 @@ store_pwm_mode(struct device *dev, struc
  			const char *buf, size_t count)
  {
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
-	int nr = sensor_attr->index - 1;
+	int nr = sensor_attr->index;
  	struct i2c_client *client = to_i2c_client(dev);
  	struct w83792d_data *data = i2c_get_clientdata(client);
-	u32 val;
-	u8 pwm_mode_mask = 0;
+	u8 val = data->pwm[nr] & 0x7f;

-	val = simple_strtoul(buf, NULL, 10);
-	data->pwm_mode[nr] = SENSORS_LIMIT(val, 0, 1);
-	pwm_mode_mask = w83792d_read_value(client,
-		W83792D_REG_PWM[nr]) & 0x7f;
-	w83792d_write_value(client, W83792D_REG_PWM[nr],
-		((data->pwm_mode[nr]) << 7) | pwm_mode_mask);
+	val |= SENSORS_LIMIT(simple_strtol(buf, NULL, 10), 0, 1) ? 0x80 : 0;
+
+	if (val != data->pwm[nr]) {
+		data->pwm[nr] = val;
+		w83792d_write_value(client, W83792D_REG_PWM[nr], val);
+	}

  	return count;
  }

  static struct sensor_device_attribute sda_pwm_mode[] = {
  	SENSOR_ATTR(pwm1_mode, S_IWUSR | S_IRUGO,
-		    show_pwm_mode, store_pwm_mode, 1),
+		    show_pwm_mode, store_pwm_mode, 0),
  	SENSOR_ATTR(pwm2_mode, S_IWUSR | S_IRUGO,
-		    show_pwm_mode, store_pwm_mode, 2),
+		    show_pwm_mode, store_pwm_mode, 1),
  	SENSOR_ATTR(pwm3_mode, S_IWUSR | S_IRUGO,
-		    show_pwm_mode, store_pwm_mode, 3),
+		    show_pwm_mode, store_pwm_mode, 2),
  };


@@ -1373,7 +1371,7 @@ static struct w83792d_data *w83792d_upda
  	struct i2c_client *client = to_i2c_client(dev);
  	struct w83792d_data *data = i2c_get_clientdata(client);
  	int i, j;
-	u8 reg_array_tmp[4], pwm_array_tmp[7], reg_tmp;
+	u8 reg_array_tmp[4], reg_tmp;

  	mutex_lock(&data->update_lock);

@@ -1402,10 +1400,8 @@ static struct w83792d_data *w83792d_upda
  			data->fan_min[i] = w83792d_read_value(client,
  						W83792D_REG_FAN_MIN[i]);
  			/* Update the PWM/DC Value and PWM/DC flag */
-			pwm_array_tmp[i] = w83792d_read_value(client,
+			data->pwm[i] = w83792d_read_value(client,
  						W83792D_REG_PWM[i]);
-			data->pwm[i] = pwm_array_tmp[i] & 0x0f;
-			data->pwm_mode[i] = pwm_array_tmp[i] >> 7;
  		}

  		reg_tmp = w83792d_read_value(client, W83792D_REG_FAN_CFG);
@@ -1513,7 +1509,6 @@ static void w83792d_print_debug(struct w
  		dev_dbg(dev, "fan[%d] is: 0x%x\n", i, data->fan[i]);
  		dev_dbg(dev, "fan[%d] min is: 0x%x\n", i, data->fan_min[i]);
  		dev_dbg(dev, "pwm[%d]     is: 0x%x\n", i, data->pwm[i]);
-		dev_dbg(dev, "pwm_mode[%d] is: 0x%x\n", i, data->pwm_mode[i]);
  	}
  	dev_dbg(dev, "3 set of Temperatures: ===>\n");
  	for (i=0; i<3; i++) {




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