hwmon: (pmbus) Support per-page exponent in linear mode

Some chips use different exponents for sensors on different pages
or rails. Detect and store exponent per page to support this situation.

This fixes a problem with wrong voltages seen on UCD90120.

Reported-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Tested-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Guenter Roeck 2014-01-30 19:51:14 -08:00
parent 38dbfb59d1
commit daa436e67c
1 changed files with 36 additions and 32 deletions

View File

@ -90,7 +90,8 @@ struct pmbus_data {
u32 flags; /* from platform data */ u32 flags; /* from platform data */
int exponent; /* linear mode: exponent for output voltages */ int exponent[PMBUS_PAGES];
/* linear mode: exponent for output voltages */
const struct pmbus_driver_info *info; const struct pmbus_driver_info *info;
@ -410,7 +411,7 @@ static long pmbus_reg2data_linear(struct pmbus_data *data,
long val; long val;
if (sensor->class == PSC_VOLTAGE_OUT) { /* LINEAR16 */ if (sensor->class == PSC_VOLTAGE_OUT) { /* LINEAR16 */
exponent = data->exponent; exponent = data->exponent[sensor->page];
mantissa = (u16) sensor->data; mantissa = (u16) sensor->data;
} else { /* LINEAR11 */ } else { /* LINEAR11 */
exponent = ((s16)sensor->data) >> 11; exponent = ((s16)sensor->data) >> 11;
@ -516,7 +517,7 @@ static long pmbus_reg2data(struct pmbus_data *data, struct pmbus_sensor *sensor)
#define MIN_MANTISSA (511 * 1000) #define MIN_MANTISSA (511 * 1000)
static u16 pmbus_data2reg_linear(struct pmbus_data *data, static u16 pmbus_data2reg_linear(struct pmbus_data *data,
enum pmbus_sensor_classes class, long val) struct pmbus_sensor *sensor, long val)
{ {
s16 exponent = 0, mantissa; s16 exponent = 0, mantissa;
bool negative = false; bool negative = false;
@ -525,7 +526,7 @@ static u16 pmbus_data2reg_linear(struct pmbus_data *data,
if (val == 0) if (val == 0)
return 0; return 0;
if (class == PSC_VOLTAGE_OUT) { if (sensor->class == PSC_VOLTAGE_OUT) {
/* LINEAR16 does not support negative voltages */ /* LINEAR16 does not support negative voltages */
if (val < 0) if (val < 0)
return 0; return 0;
@ -534,10 +535,10 @@ static u16 pmbus_data2reg_linear(struct pmbus_data *data,
* For a static exponents, we don't have a choice * For a static exponents, we don't have a choice
* but to adjust the value to it. * but to adjust the value to it.
*/ */
if (data->exponent < 0) if (data->exponent[sensor->page] < 0)
val <<= -data->exponent; val <<= -data->exponent[sensor->page];
else else
val >>= data->exponent; val >>= data->exponent[sensor->page];
val = DIV_ROUND_CLOSEST(val, 1000); val = DIV_ROUND_CLOSEST(val, 1000);
return val & 0xffff; return val & 0xffff;
} }
@ -548,14 +549,14 @@ static u16 pmbus_data2reg_linear(struct pmbus_data *data,
} }
/* Power is in uW. Convert to mW before converting. */ /* Power is in uW. Convert to mW before converting. */
if (class == PSC_POWER) if (sensor->class == PSC_POWER)
val = DIV_ROUND_CLOSEST(val, 1000L); val = DIV_ROUND_CLOSEST(val, 1000L);
/* /*
* For simplicity, convert fan data to milli-units * For simplicity, convert fan data to milli-units
* before calculating the exponent. * before calculating the exponent.
*/ */
if (class == PSC_FAN) if (sensor->class == PSC_FAN)
val = val * 1000; val = val * 1000;
/* Reduce large mantissa until it fits into 10 bit */ /* Reduce large mantissa until it fits into 10 bit */
@ -585,22 +586,22 @@ static u16 pmbus_data2reg_linear(struct pmbus_data *data,
} }
static u16 pmbus_data2reg_direct(struct pmbus_data *data, static u16 pmbus_data2reg_direct(struct pmbus_data *data,
enum pmbus_sensor_classes class, long val) struct pmbus_sensor *sensor, long val)
{ {
long m, b, R; long m, b, R;
m = data->info->m[class]; m = data->info->m[sensor->class];
b = data->info->b[class]; b = data->info->b[sensor->class];
R = data->info->R[class]; R = data->info->R[sensor->class];
/* Power is in uW. Adjust R and b. */ /* Power is in uW. Adjust R and b. */
if (class == PSC_POWER) { if (sensor->class == PSC_POWER) {
R -= 3; R -= 3;
b *= 1000; b *= 1000;
} }
/* Calculate Y = (m * X + b) * 10^R */ /* Calculate Y = (m * X + b) * 10^R */
if (class != PSC_FAN) { if (sensor->class != PSC_FAN) {
R -= 3; /* Adjust R and b for data in milli-units */ R -= 3; /* Adjust R and b for data in milli-units */
b *= 1000; b *= 1000;
} }
@ -619,7 +620,7 @@ static u16 pmbus_data2reg_direct(struct pmbus_data *data,
} }
static u16 pmbus_data2reg_vid(struct pmbus_data *data, static u16 pmbus_data2reg_vid(struct pmbus_data *data,
enum pmbus_sensor_classes class, long val) struct pmbus_sensor *sensor, long val)
{ {
val = clamp_val(val, 500, 1600); val = clamp_val(val, 500, 1600);
@ -627,20 +628,20 @@ static u16 pmbus_data2reg_vid(struct pmbus_data *data,
} }
static u16 pmbus_data2reg(struct pmbus_data *data, static u16 pmbus_data2reg(struct pmbus_data *data,
enum pmbus_sensor_classes class, long val) struct pmbus_sensor *sensor, long val)
{ {
u16 regval; u16 regval;
switch (data->info->format[class]) { switch (data->info->format[sensor->class]) {
case direct: case direct:
regval = pmbus_data2reg_direct(data, class, val); regval = pmbus_data2reg_direct(data, sensor, val);
break; break;
case vid: case vid:
regval = pmbus_data2reg_vid(data, class, val); regval = pmbus_data2reg_vid(data, sensor, val);
break; break;
case linear: case linear:
default: default:
regval = pmbus_data2reg_linear(data, class, val); regval = pmbus_data2reg_linear(data, sensor, val);
break; break;
} }
return regval; return regval;
@ -746,7 +747,7 @@ static ssize_t pmbus_set_sensor(struct device *dev,
return -EINVAL; return -EINVAL;
mutex_lock(&data->update_lock); mutex_lock(&data->update_lock);
regval = pmbus_data2reg(data, sensor->class, val); regval = pmbus_data2reg(data, sensor, val);
ret = _pmbus_write_word_data(client, sensor->page, sensor->reg, regval); ret = _pmbus_write_word_data(client, sensor->page, sensor->reg, regval);
if (ret < 0) if (ret < 0)
rv = ret; rv = ret;
@ -1643,12 +1644,13 @@ static int pmbus_find_attributes(struct i2c_client *client,
* This function is called for all chips. * This function is called for all chips.
*/ */
static int pmbus_identify_common(struct i2c_client *client, static int pmbus_identify_common(struct i2c_client *client,
struct pmbus_data *data) struct pmbus_data *data, int page)
{ {
int vout_mode = -1; int vout_mode = -1;
if (pmbus_check_byte_register(client, 0, PMBUS_VOUT_MODE)) if (pmbus_check_byte_register(client, page, PMBUS_VOUT_MODE))
vout_mode = _pmbus_read_byte_data(client, 0, PMBUS_VOUT_MODE); vout_mode = _pmbus_read_byte_data(client, page,
PMBUS_VOUT_MODE);
if (vout_mode >= 0 && vout_mode != 0xff) { if (vout_mode >= 0 && vout_mode != 0xff) {
/* /*
* Not all chips support the VOUT_MODE command, * Not all chips support the VOUT_MODE command,
@ -1659,7 +1661,7 @@ static int pmbus_identify_common(struct i2c_client *client,
if (data->info->format[PSC_VOLTAGE_OUT] != linear) if (data->info->format[PSC_VOLTAGE_OUT] != linear)
return -ENODEV; return -ENODEV;
data->exponent = ((s8)(vout_mode << 3)) >> 3; data->exponent[page] = ((s8)(vout_mode << 3)) >> 3;
break; break;
case 1: /* VID mode */ case 1: /* VID mode */
if (data->info->format[PSC_VOLTAGE_OUT] != vid) if (data->info->format[PSC_VOLTAGE_OUT] != vid)
@ -1674,7 +1676,7 @@ static int pmbus_identify_common(struct i2c_client *client,
} }
} }
pmbus_clear_fault_page(client, 0); pmbus_clear_fault_page(client, page);
return 0; return 0;
} }
@ -1682,7 +1684,7 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
struct pmbus_driver_info *info) struct pmbus_driver_info *info)
{ {
struct device *dev = &client->dev; struct device *dev = &client->dev;
int ret; int page, ret;
/* /*
* Some PMBus chips don't support PMBUS_STATUS_BYTE, so try * Some PMBus chips don't support PMBUS_STATUS_BYTE, so try
@ -1715,10 +1717,12 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
return -ENODEV; return -ENODEV;
} }
ret = pmbus_identify_common(client, data); for (page = 0; page < info->pages; page++) {
if (ret < 0) { ret = pmbus_identify_common(client, data, page);
dev_err(dev, "Failed to identify chip capabilities\n"); if (ret < 0) {
return ret; dev_err(dev, "Failed to identify chip capabilities\n");
return ret;
}
} }
return 0; return 0;
} }