hwmon: (pmbus/adm1275) support PMBUS_VIRT_*_SAMPLES

The device supports setting the number of samples for averaging the
measurements. There are two separate settings - PWR_AVG for averaging
PIN and VI_AVG for averaging VIN/VAUX/IOUT, both being part of
PMON_CONFIG register. The values are stored as exponent of base 2 of the
actual number of samples that will be taken.

Signed-off-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
[groeck: Dropped unused variables]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/pmbus/adm1275.c b/drivers/hwmon/pmbus/adm1275.c
index 82052b6611c9d6b260cef33b7a6d806494c07101..a477ce0474bb792ae8ab55ec72ef1850e8ac5890 100644 (file)
--- a/drivers/hwmon/pmbus/adm1275.c
+++ b/drivers/hwmon/pmbus/adm1275.c
@@ -14,6 +14,8 @@
 #include <linux/slab.h>
 #include <linux/i2c.h>
 #include <linux/bitops.h>
+#include <linux/bitfield.h>
+#include <linux/log2.h>
 #include "pmbus.h"
 
 enum chips { adm1075, adm1272, adm1275, adm1276, adm1278, adm1293, adm1294 };
@@ -69,6 +71,10 @@ enum chips { adm1075, adm1272, adm1275, adm1276, adm1278, adm1293, adm1294 };
 #define ADM1075_VAUX_OV_WARN           BIT(7)
 #define ADM1075_VAUX_UV_WARN           BIT(6)
 
+#define ADM1275_PWR_AVG_MASK           GENMASK(13, 11)
+#define ADM1275_VI_AVG_MASK            GENMASK(10, 8)
+#define ADM1275_SAMPLES_AVG_MAX        128
+
 struct adm1275_data {
        int id;
        bool have_oc_fault;
@@ -155,6 +161,32 @@ static const struct coefficients adm1293_coefficients[] = {
        [18] = { 7658, 0, -3 },         /* power, 21V, irange200 */
 };
 
+static inline int adm1275_read_pmon_config(struct i2c_client *client, u16 mask)
+{
+       int ret;
+
+       ret = i2c_smbus_read_word_data(client, ADM1275_PMON_CONFIG);
+       if (ret < 0)
+               return ret;
+
+       return FIELD_GET(mask, (u16)ret);
+}
+
+static inline int adm1275_write_pmon_config(struct i2c_client *client, u16 mask,
+                                           u16 word)
+{
+       int ret;
+
+       ret = i2c_smbus_read_word_data(client, ADM1275_PMON_CONFIG);
+       if (ret < 0)
+               return ret;
+
+       word = FIELD_PREP(mask, word) | (ret & ~mask);
+       ret = i2c_smbus_write_word_data(client, ADM1275_PMON_CONFIG, word);
+
+       return ret;
+}
+
 static int adm1275_read_word_data(struct i2c_client *client, int page, int reg)
 {
        const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
@@ -233,6 +265,19 @@ static int adm1275_read_word_data(struct i2c_client *client, int page, int reg)
                if (!data->have_temp_max)
                        return -ENXIO;
                break;
+       case PMBUS_VIRT_POWER_SAMPLES:
+               ret = adm1275_read_pmon_config(client, ADM1275_PWR_AVG_MASK);
+               if (ret < 0)
+                       break;
+               ret = BIT(ret);
+               break;
+       case PMBUS_VIRT_IN_SAMPLES:
+       case PMBUS_VIRT_CURR_SAMPLES:
+               ret = adm1275_read_pmon_config(client, ADM1275_VI_AVG_MASK);
+               if (ret < 0)
+                       break;
+               ret = BIT(ret);
+               break;
        default:
                ret = -ENODATA;
                break;
@@ -277,6 +322,17 @@ static int adm1275_write_word_data(struct i2c_client *client, int page, int reg,
        case PMBUS_VIRT_RESET_TEMP_HISTORY:
                ret = pmbus_write_word_data(client, 0, ADM1278_PEAK_TEMP, 0);
                break;
+       case PMBUS_VIRT_POWER_SAMPLES:
+               word = clamp_val(word, 1, ADM1275_SAMPLES_AVG_MAX);
+               ret = adm1275_write_pmon_config(client, ADM1275_PWR_AVG_MASK,
+                                               ilog2(word));
+               break;
+       case PMBUS_VIRT_IN_SAMPLES:
+       case PMBUS_VIRT_CURR_SAMPLES:
+               word = clamp_val(word, 1, ADM1275_SAMPLES_AVG_MAX);
+               ret = adm1275_write_pmon_config(client, ADM1275_VI_AVG_MASK,
+                                               ilog2(word));
+               break;
        default:
                ret = -ENODATA;
                break;
@@ -430,7 +486,8 @@ static int adm1275_probe(struct i2c_client *client,
        info->format[PSC_CURRENT_OUT] = direct;
        info->format[PSC_POWER] = direct;
        info->format[PSC_TEMPERATURE] = direct;
-       info->func[0] = PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
+       info->func[0] = PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
+                       PMBUS_HAVE_SAMPLES;
 
        info->read_word_data = adm1275_read_word_data;
        info->read_byte_data = adm1275_read_byte_data;