Implement support for setting the VOUT_SCALE_LOOP PMBus register
based on an optional device tree property
"mps,vout-fb-divider-ratio-permille".
This allows the driver to provide the correct VOUT value depending
on the feedback voltage divider configuration for chips where the
bootloader does not configure the VOUT_SCALE_LOOP register.
Signed-off-by: Pawel Dembicki <paweldembicki@xxxxxxxxx>
---
v2:
- rename property to mps,vout-fb-divider-ratio-permille
- add register value range checking
---
drivers/hwmon/pmbus/mpq8785.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/drivers/hwmon/pmbus/mpq8785.c b/drivers/hwmon/pmbus/mpq8785.c
index 34245d0d2125..1d0e7ac9daf4 100644
--- a/drivers/hwmon/pmbus/mpq8785.c
+++ b/drivers/hwmon/pmbus/mpq8785.c
@@ -12,6 +12,13 @@
enum chips { mpq8785, mpm82504, mpm3695, mpm3695_25 };
+static u16 voltage_scale_loop_max_val[] = {
+ GENMASK(10, 0), /* mpq8785 */
+ GENMASK(9, 0), /* mpm82504 */
+ GENMASK(9, 0), /* mpm3695 */
+ GENMASK(11, 0), /* mpm3695_25 */
+};
+
static int mpq8785_identify(struct i2c_client *client,
struct pmbus_driver_info *info)
{
@@ -99,6 +106,8 @@ static int mpq8785_probe(struct i2c_client *client)
struct device *dev = &client->dev;
struct pmbus_driver_info *info;
enum chips chip_id;
+ u32 voltage_scale;
+ int ret;
info = devm_kmemdup(dev, &mpq8785_info, sizeof(*info), GFP_KERNEL);
if (!info)
@@ -126,6 +135,18 @@ static int mpq8785_probe(struct i2c_client *client)
return -ENODEV;
}
+ if (!of_property_read_u32(dev->of_node,
+ "mps,vout-fb-divider-ratio-permille",
+ &voltage_scale)) {
+ if (voltage_scale > voltage_scale_loop_max_val[chip_id])
+ return -EINVAL;
+
+ ret = i2c_smbus_write_word_data(client, PMBUS_VOUT_SCALE_LOOP,
+ voltage_scale);
+ if (ret)
+ return ret;
+ }
+
return pmbus_do_probe(client, info);
};
--
2.43.0
