[PATCH] adm1275: support PMBUS_VIRT_*_SAMPLES

Adamski, Krzysztof (Nokia - PL/Wroclaw)
2019-05-24T12:49:32Z

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>
---
drivers/hwmon/pmbus/adm1275.c | 68 ++++++++++++++++++++++++++++++++++-
1 file changed, 67 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/pmbus/adm1275.c b/drivers/hwmon/pmbus/adm1275.c
index f569372c9204..4efe1a9df563 100644
--- a/drivers/hwmon/pmbus/adm1275.c
+++ b/drivers/hwmon/pmbus/adm1275.c
@@ -23,6 +23,8 @@
#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 };
@@ -78,6 +80,10 @@ 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;
@@ -90,6 +96,7 @@ struct adm1275_data {
bool have_pin_max;
bool have_temp_max;
struct pmbus_driver_info info;
+ struct mutex lock;
};

#define to_adm1275_data(x) container_of(x, struct adm1275_data, info)
@@ -164,6 +171,38 @@ static const struct coefficients adm1293_coefficients[] = {
[18] = { 7658, 0, -3 }, /* power, 21V, irange200 */
};

+static inline int adm1275_read_pmon_config(struct i2c_client *client, u64 mask)
+{
+ int ret;
+
+ ret = i2c_smbus_read_word_data(client, ADM1275_PMON_CONFIG);
+ if (ret < 0)
+ return ret;
+
+ return FIELD_GET(mask, ret);
+}
+
+static inline int adm1275_write_pmon_config(struct i2c_client *client, u64 mask,
+ u16 word)
+{
+ const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+ struct adm1275_data *data = to_adm1275_data(info);
+ int ret;
+
+ mutex_lock(&data->lock);
+ ret = i2c_smbus_read_word_data(client, ADM1275_PMON_CONFIG);
+ if (ret < 0) {
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+
+ word = FIELD_PREP(mask, word) | (ret & ~mask);
+ ret = i2c_smbus_write_word_data(client, ADM1275_PMON_CONFIG, word);
+ mutex_unlock(&data->lock);
+
+ 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);
@@ -242,6 +281,19 @@ 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 = 1 << 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 = 1 << ret;
+ break;
default:
ret = -ENODATA;
break;
@@ -286,6 +338,17 @@ 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;
@@ -422,6 +485,8 @@ static int adm1275_probe(struct i2c_client *client,
if (!data)
return -ENOMEM;

+ mutex_init(&data->lock);
+
if (of_property_read_u32(client->dev.of_node,
"shunt-resistor-micro-ohms", &shunt))
shunt = 1000; /* 1 mOhm if not set via DT */
@@ -439,7 +504,8 @@ 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;
--
2.20.1