Some PMBus chips respond with invalid data when reading the WRITE_PROTECT
register. For such chips, this flag should be set so that the PMBus core
driver doesn't use the WRITE_PROTECT command to determine it's behavior.
Signed-off-by: Erik Rosen <erik.rosen@xxxxxxxxxxxxx>
---
drivers/hwmon/pmbus/pmbus_core.c | 9 ++++++---
include/linux/pmbus.h | 9 +++++++++
2 files changed, 15 insertions(+), 3 deletions(-)
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index c92ad5764301..944570edf37f 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -2265,9 +2265,12 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
* faults, and we should not try it. Also, in that case, writes into
* limit registers need to be disabled.
*/
- ret = i2c_smbus_read_byte_data(client, PMBUS_WRITE_PROTECT);
- if (ret > 0 && (ret & PB_WP_ANY))
- data->flags |= PMBUS_WRITE_PROTECTED | PMBUS_SKIP_STATUS_CHECK;
+ if (!(data->flags & PMBUS_NO_WRITE_PROTECT)) {
+ ret = i2c_smbus_read_byte_data(client, PMBUS_WRITE_PROTECT);
+ if (ret > 0 && (ret & PB_WP_ANY))
+ data->flags |= PMBUS_WRITE_PROTECTED
+ | PMBUS_SKIP_STATUS_CHECK;
+ }
if (data->info->pages)
pmbus_clear_faults(client);
diff --git a/include/linux/pmbus.h b/include/linux/pmbus.h
index 12cbbf305969..f720470b1bab 100644
--- a/include/linux/pmbus.h
+++ b/include/linux/pmbus.h
@@ -43,6 +43,15 @@
*/
#define PMBUS_NO_CAPABILITY BIT(2)
+/*
+ * PMBUS_NO_WRITE_PROTECT
+ *
+ * Some PMBus chips respond with invalid data when reading the WRITE_PROTECT
+ * register. For such chips, this flag should be set so that the PMBus core
+ * driver doesn't use the WRITE_PROTECT command to determine it's behavior.
+ */
+#define PMBUS_NO_WRITE_PROTECT BIT(4)
+
struct pmbus_platform_data {
u32 flags; /* Device specific flags */
--
2.20.1
