hwmon: (w83791d) Use fan divisor bits from vbat register
Update w83791d with fan bits in vbat mon register (7.48 of the
datasheet). This change allows all fans to have a divisor of 128,
and fixes a problem with incorrectly reported fan speeds.
Signed-off-by: Marc Hulsman <m.hulsman@tudelft.nl>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/hwmon/w83791d.c b/drivers/hwmon/w83791d.c
index e4e91c9..daa7d12 100644
--- a/drivers/hwmon/w83791d.c
+++ b/drivers/hwmon/w83791d.c
@@ -233,11 +233,9 @@
static u8 div_to_reg(int nr, long val)
{
int i;
- int max;
- /* first three fan's divisor max out at 8, rest max out at 128 */
- max = (nr < 3) ? 8 : 128;
- val = SENSORS_LIMIT(val, 1, max) >> 1;
+ /* fan divisors max out at 128 */
+ val = SENSORS_LIMIT(val, 1, 128) >> 1;
for (i = 0; i < 7; i++) {
if (val == 0)
break;
@@ -530,6 +528,7 @@
unsigned long min;
u8 tmp_fan_div;
u8 fan_div_reg;
+ u8 vbat_reg;
int indx = 0;
u8 keep_mask = 0;
u8 new_shift = 0;
@@ -581,6 +580,16 @@
w83791d_write(client, W83791D_REG_FAN_DIV[indx],
fan_div_reg | tmp_fan_div);
+ /* Bit 2 of fans 0-2 is stored in the vbat register (bits 5-7) */
+ if (nr < 3) {
+ keep_mask = ~(1 << (nr + 5));
+ vbat_reg = w83791d_read(client, W83791D_REG_VBAT)
+ & keep_mask;
+ tmp_fan_div = (data->fan_div[nr] << (3 + nr)) & ~keep_mask;
+ w83791d_write(client, W83791D_REG_VBAT,
+ vbat_reg | tmp_fan_div);
+ }
+
/* Restore fan_min */
data->fan_min[nr] = fan_to_reg(min, DIV_FROM_REG(data->fan_div[nr]));
w83791d_write(client, W83791D_REG_FAN_MIN[nr], data->fan_min[nr]);
@@ -1182,6 +1191,7 @@
struct w83791d_data *data = i2c_get_clientdata(client);
int i, j;
u8 reg_array_tmp[3];
+ u8 vbat_reg;
mutex_lock(&data->update_lock);
@@ -1219,6 +1229,12 @@
data->fan_div[3] = reg_array_tmp[2] & 0x07;
data->fan_div[4] = (reg_array_tmp[2] >> 4) & 0x07;
+ /* The fan divisor for fans 0-2 get bit 2 from
+ bits 5-7 respectively of vbat register */
+ vbat_reg = w83791d_read(client, W83791D_REG_VBAT);
+ for (i = 0; i < 3; i++)
+ data->fan_div[i] |= (vbat_reg >> (3 + i)) & 0x04;
+
/* Update the first temperature sensor */
for (i = 0; i < 3; i++) {
data->temp1[i] = w83791d_read(client,