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authorEddie James <eajames@linux.ibm.com>2020-12-22 09:26:39 -0600
committerGuenter Roeck <linux@roeck-us.net>2021-01-27 17:44:18 -0800
commite5befc024cb4515d815662ed8746712cc5366bfc (patch)
treece946cdb9763b7381b8fda0747f02ce010deeb9e
parentc8d0d3fa946976c6bc69589375d7d063f0cb1492 (diff)
downloadlwn-e5befc024cb4515d815662ed8746712cc5366bfc.tar.gz
lwn-e5befc024cb4515d815662ed8746712cc5366bfc.zip
hwmon: (pmbus) Add a PMBUS_NO_CAPABILITY platform data flag
Some PMBus chips don't respond with valid data when reading the CAPABILITY register. Add a flag that device drivers can set so that the PMBus core driver doesn't use CAPABILITY to determine it's behavior. Signed-off-by: Eddie James <eajames@linux.ibm.com> Link: https://lore.kernel.org/r/20201222152640.27749-2-eajames@linux.ibm.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
-rw-r--r--drivers/hwmon/pmbus/pmbus_core.c8
-rw-r--r--include/linux/pmbus.h9
2 files changed, 14 insertions, 3 deletions
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 192442b3b7a2..906c9fec9cce 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -2204,9 +2204,11 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
}
/* Enable PEC if the controller supports it */
- ret = i2c_smbus_read_byte_data(client, PMBUS_CAPABILITY);
- if (ret >= 0 && (ret & PB_CAPABILITY_ERROR_CHECK))
- client->flags |= I2C_CLIENT_PEC;
+ if (!(data->flags & PMBUS_NO_CAPABILITY)) {
+ ret = i2c_smbus_read_byte_data(client, PMBUS_CAPABILITY);
+ if (ret >= 0 && (ret & PB_CAPABILITY_ERROR_CHECK))
+ client->flags |= I2C_CLIENT_PEC;
+ }
/*
* Check if the chip is write protected. If it is, we can not clear
diff --git a/include/linux/pmbus.h b/include/linux/pmbus.h
index 1ea5bae708a1..12cbbf305969 100644
--- a/include/linux/pmbus.h
+++ b/include/linux/pmbus.h
@@ -34,6 +34,15 @@
*/
#define PMBUS_WRITE_PROTECTED BIT(1)
+/*
+ * PMBUS_NO_CAPABILITY
+ *
+ * Some PMBus chips don't respond with valid data when reading the CAPABILITY
+ * register. For such chips, this flag should be set so that the PMBus core
+ * driver doesn't use CAPABILITY to determine it's behavior.
+ */
+#define PMBUS_NO_CAPABILITY BIT(2)
+
struct pmbus_platform_data {
u32 flags; /* Device specific flags */