summaryrefslogtreecommitdiff
path: root/drivers/hwmon/w83795.c
diff options
context:
space:
mode:
authorJean Delvare <khali@linux-fr.org>2010-10-28 22:31:47 +0400
committerJean Delvare <khali@endymion.delvare>2010-10-28 22:31:47 +0400
commit01879a855fb6bdb3fb820344a7a145de8a5cdbda (patch)
tree152e9a958bfdd71692455d18348623b1cbb40929 /drivers/hwmon/w83795.c
parent0e256018b0f35d1b22ca37e1d0e207f7ba3d0076 (diff)
downloadlinux-01879a855fb6bdb3fb820344a7a145de8a5cdbda.tar.xz
hwmon: (w83795) Fix PWM duty cycle frequency attributes
The PWM duty cycle frequenty attributes are improperly named (fanN_div instead of pwmN_div) and contain raw values instead of actual frequencies. Rename them and fix their contents. Also improve the logic when the user asks for a new frequency, to always pick the closest supported frequency. The algorithm could certainly be optimized, but the operation is infrequent enough that I don't think it's worth the effort. Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/hwmon/w83795.c')
-rw-r--r--drivers/hwmon/w83795.c90
1 files changed, 62 insertions, 28 deletions
diff --git a/drivers/hwmon/w83795.c b/drivers/hwmon/w83795.c
index 458fb297f696..58c61f11ed66 100644
--- a/drivers/hwmon/w83795.c
+++ b/drivers/hwmon/w83795.c
@@ -200,7 +200,6 @@ static const u8 IN_LSB_SHIFT_IDX[][2] = {
#define W83795_REG_FCMS2 0x208
#define W83795_REG_TFMR(index) (0x202 + (index))
#define W83795_REG_FOMC 0x20F
-#define W83795_REG_FOPFP(index) (0x218 + (index))
#define W83795_REG_TSS(index) (0x209 + (index))
@@ -208,18 +207,13 @@ static const u8 IN_LSB_SHIFT_IDX[][2] = {
#define PWM_START 1
#define PWM_NONSTOP 2
#define PWM_STOP_TIME 3
-#define PWM_DIV 4
+#define PWM_FREQ 4
#define W83795_REG_PWM(index, nr) \
(((nr) == 0 ? 0x210 : \
(nr) == 1 ? 0x220 : \
(nr) == 2 ? 0x228 : \
(nr) == 3 ? 0x230 : 0x218) + (index))
-#define W83795_REG_FOPFP_DIV(index) \
- (((index) < 8) ? ((index) + 1) : \
- ((index) == 8) ? 12 : \
- (16 << ((index) - 9)))
-
#define W83795_REG_FTSH(index) (0x240 + (index) * 2)
#define W83795_REG_FTSL(index) (0x241 + (index) * 2)
#define W83795_REG_TFTS 0x250
@@ -304,6 +298,50 @@ static inline s8 temp_to_reg(long val, s8 min, s8 max)
return SENSORS_LIMIT((val < 0 ? -val : val) / 1000, min, max);
}
+static const u16 pwm_freq_cksel0[16] = {
+ 1024, 512, 341, 256, 205, 171, 146, 128,
+ 85, 64, 32, 16, 8, 4, 2, 1
+};
+
+static unsigned int pwm_freq_from_reg(u8 reg, u16 clkin)
+{
+ unsigned long base_clock;
+
+ if (reg & 0x80) {
+ base_clock = clkin * 1000 / ((clkin == 48000) ? 384 : 256);
+ return base_clock / ((reg & 0x7f) + 1);
+ } else
+ return pwm_freq_cksel0[reg & 0x0f];
+}
+
+static u8 pwm_freq_to_reg(unsigned long val, u16 clkin)
+{
+ unsigned long base_clock;
+ u8 reg0, reg1;
+ unsigned long best0, best1;
+
+ /* Best fit for cksel = 0 */
+ for (reg0 = 0; reg0 < ARRAY_SIZE(pwm_freq_cksel0) - 1; reg0++) {
+ if (val > (pwm_freq_cksel0[reg0] +
+ pwm_freq_cksel0[reg0 + 1]) / 2)
+ break;
+ }
+ if (val < 375) /* cksel = 1 can't beat this */
+ return reg0;
+ best0 = pwm_freq_cksel0[reg0];
+
+ /* Best fit for cksel = 1 */
+ base_clock = clkin * 1000 / ((clkin == 48000) ? 384 : 256);
+ reg1 = SENSORS_LIMIT(DIV_ROUND_CLOSEST(base_clock, val), 1, 128);
+ best1 = base_clock / reg1;
+ reg1 = 0x80 | (reg1 - 1);
+
+ /* Choose the closest one */
+ if (abs(val - best0) > abs(val - best1))
+ return reg1;
+ else
+ return reg0;
+}
enum chip_types {w83795g, w83795adg};
@@ -343,7 +381,8 @@ struct w83795_data {
* no config register, only affected by chip
* type */
u8 pwm[8][5]; /* Register value, output, start, non stop, stop
- * time, div */
+ * time, freq */
+ u16 clkin; /* CLKIN frequency in kHz */
u8 pwm_fcms[2]; /* Register value */
u8 pwm_tfmr[6]; /* Register value */
u8 pwm_fomc; /* Register value */
@@ -688,14 +727,14 @@ show_pwm(struct device *dev, struct device_attribute *attr, char *buf)
to_sensor_dev_attr_2(attr);
int nr = sensor_attr->nr;
int index = sensor_attr->index;
- u16 val;
+ unsigned int val;
switch (nr) {
case PWM_STOP_TIME:
val = time_from_reg(data->pwm[index][nr]);
break;
- case PWM_DIV:
- val = W83795_REG_FOPFP_DIV(data->pwm[index][nr] & 0x0f);
+ case PWM_FREQ:
+ val = pwm_freq_from_reg(data->pwm[index][nr], data->clkin);
break;
default:
val = data->pwm[index][nr];
@@ -716,7 +755,6 @@ store_pwm(struct device *dev, struct device_attribute *attr,
int nr = sensor_attr->nr;
int index = sensor_attr->index;
unsigned long val;
- int i;
if (strict_strtoul(buf, 10, &val) < 0)
return -EINVAL;
@@ -726,28 +764,17 @@ store_pwm(struct device *dev, struct device_attribute *attr,
case PWM_STOP_TIME:
val = time_to_reg(val);
break;
- case PWM_DIV:
- for (i = 0; i < 16; i++) {
- if (W83795_REG_FOPFP_DIV(i) == val) {
- val = i;
- break;
- }
- }
- if (i >= 16)
- goto err_end;
- val |= w83795_read(client, W83795_REG_PWM(index, nr)) & 0x80;
+ case PWM_FREQ:
+ val = pwm_freq_to_reg(val, data->clkin);
break;
default:
val = SENSORS_LIMIT(val, 0, 0xff);
break;
}
w83795_write(client, W83795_REG_PWM(index, nr), val);
- data->pwm[index][nr] = val & 0xff;
+ data->pwm[index][nr] = val;
mutex_unlock(&data->update_lock);
return count;
-err_end:
- mutex_unlock(&data->update_lock);
- return -EINVAL;
}
static ssize_t
@@ -1502,8 +1529,8 @@ store_sf_setup(struct device *dev, struct device_attribute *attr,
show_pwm, store_pwm, PWM_START, index - 1), \
SENSOR_ATTR_2(pwm##index##_stop_time, S_IWUSR | S_IRUGO, \
show_pwm, store_pwm, PWM_STOP_TIME, index - 1), \
- SENSOR_ATTR_2(fan##index##_div, S_IWUSR | S_IRUGO, \
- show_pwm, store_pwm, PWM_DIV, index - 1), \
+ SENSOR_ATTR_2(pwm##index##_freq, S_IWUSR | S_IRUGO, \
+ show_pwm, store_pwm, PWM_FREQ, index - 1), \
SENSOR_ATTR_2(pwm##index##_enable, S_IWUSR | S_IRUGO, \
show_pwm_enable, store_pwm_enable, NOT_USED, index - 1), \
SENSOR_ATTR_2(fan##index##_target, S_IWUSR | S_IRUGO, \
@@ -1685,6 +1712,10 @@ static const struct sensor_device_attribute_2 sda_single_files[] = {
static void w83795_init_client(struct i2c_client *client)
{
+ struct w83795_data *data = i2c_get_clientdata(client);
+ static const u16 clkin[4] = { /* in kHz */
+ 14318, 24000, 33333, 48000
+ };
u8 config;
if (reset)
@@ -1697,6 +1728,9 @@ static void w83795_init_client(struct i2c_client *client)
w83795_write(client, W83795_REG_CONFIG,
config | W83795_REG_CONFIG_START);
}
+
+ data->clkin = clkin[(config >> 3) & 0x3];
+ dev_dbg(&client->dev, "clkin = %u kHz\n", data->clkin);
}
static int w83795_get_device_id(struct i2c_client *client)