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authorErik Rosen <erik.rosen@metormote.com>2021-06-09 11:32:06 +0200
committerGuenter Roeck <linux@roeck-us.net>2021-06-17 04:21:46 -0700
commite8e00c83a268d5b7d2f5bd490c2269c1ede76a07 (patch)
tree77b6dfb7157089a0dd7499a3e15d1ad9e8e5a95d /drivers/hwmon
parentdbc0860f7a3d43604c380822a456d26ef6f70a06 (diff)
hwmon: (pmbus) Add support for reading direct mode coefficients
Add support for reading and decoding direct format coefficients to the PMBus core driver. If the new flag PMBUS_USE_COEFFICIENTS_CMD is set, the driver will use the COEFFICIENTS register together with the information in the pmbus_sensor_attr structs to initialize relevant coefficients for the direct mode format. Signed-off-by: Erik Rosen <erik.rosen@metormote.com> [groeck: Initialize ret with -EINVAL in pmbus_init_coefficients()] Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/pmbus/pmbus_core.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index a5367df1cee8..c4f557c8955b 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -2142,6 +2142,111 @@ static int pmbus_find_attributes(struct i2c_client *client,
}
/*
+ * The pmbus_class_attr_map structure maps one sensor class to
+ * it's corresponding sensor attributes array.
+ */
+struct pmbus_class_attr_map {
+ enum pmbus_sensor_classes class;
+ int nattr;
+ const struct pmbus_sensor_attr *attr;
+};
+
+static const struct pmbus_class_attr_map class_attr_map[] = {
+ {
+ .class = PSC_VOLTAGE_IN,
+ .attr = voltage_attributes,
+ .nattr = ARRAY_SIZE(voltage_attributes),
+ }, {
+ .class = PSC_VOLTAGE_OUT,
+ .attr = voltage_attributes,
+ .nattr = ARRAY_SIZE(voltage_attributes),
+ }, {
+ .class = PSC_CURRENT_IN,
+ .attr = current_attributes,
+ .nattr = ARRAY_SIZE(current_attributes),
+ }, {
+ .class = PSC_CURRENT_OUT,
+ .attr = current_attributes,
+ .nattr = ARRAY_SIZE(current_attributes),
+ }, {
+ .class = PSC_POWER,
+ .attr = power_attributes,
+ .nattr = ARRAY_SIZE(power_attributes),
+ }, {
+ .class = PSC_TEMPERATURE,
+ .attr = temp_attributes,
+ .nattr = ARRAY_SIZE(temp_attributes),
+ }
+};
+
+/*
+ * Read the coefficients for direct mode.
+ */
+static int pmbus_read_coefficients(struct i2c_client *client,
+ struct pmbus_driver_info *info,
+ const struct pmbus_sensor_attr *attr)
+{
+ int rv;
+ union i2c_smbus_data data;
+ enum pmbus_sensor_classes class = attr->class;
+ s8 R;
+ s16 m, b;
+
+ data.block[0] = 2;
+ data.block[1] = attr->reg;
+ data.block[2] = 0x01;
+
+ rv = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_WRITE, PMBUS_COEFFICIENTS,
+ I2C_SMBUS_BLOCK_PROC_CALL, &data);
+
+ if (rv < 0)
+ return rv;
+
+ if (data.block[0] != 5)
+ return -EIO;
+
+ m = data.block[1] | (data.block[2] << 8);
+ b = data.block[3] | (data.block[4] << 8);
+ R = data.block[5];
+ info->m[class] = m;
+ info->b[class] = b;
+ info->R[class] = R;
+
+ return rv;
+}
+
+static int pmbus_init_coefficients(struct i2c_client *client,
+ struct pmbus_driver_info *info)
+{
+ int i, n, ret = -EINVAL;
+ const struct pmbus_class_attr_map *map;
+ const struct pmbus_sensor_attr *attr;
+
+ for (i = 0; i < ARRAY_SIZE(class_attr_map); i++) {
+ map = &class_attr_map[i];
+ if (info->format[map->class] != direct)
+ continue;
+ for (n = 0; n < map->nattr; n++) {
+ attr = &map->attr[n];
+ if (map->class != attr->class)
+ continue;
+ ret = pmbus_read_coefficients(client, info, attr);
+ if (ret >= 0)
+ break;
+ }
+ if (ret < 0) {
+ dev_err(&client->dev,
+ "No coefficients found for sensor class %d\n",
+ map->class);
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+/*
* Identify chip parameters.
* This function is called for all chips.
*/
@@ -2262,6 +2367,17 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
return ret;
}
}
+
+ if (data->flags & PMBUS_USE_COEFFICIENTS_CMD) {
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_BLOCK_PROC_CALL))
+ return -ENODEV;
+
+ ret = pmbus_init_coefficients(client, info);
+ if (ret < 0)
+ return ret;
+ }
+
return 0;
}