diff options
| -rw-r--r-- | drivers/hwmon/pmbus/pmbus_core.c | 2 | ||||
| -rw-r--r-- | include/linux/pmbus.h | 13 |
2 files changed, 15 insertions, 0 deletions
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c index bbd745178147..1f7fa5337974 100644 --- a/drivers/hwmon/pmbus/pmbus_core.c +++ b/drivers/hwmon/pmbus/pmbus_core.c @@ -523,6 +523,8 @@ static bool pmbus_check_register(struct i2c_client *client, rv = func(client, page, reg); if (rv >= 0 && !(data->flags & PMBUS_SKIP_STATUS_CHECK)) rv = pmbus_check_status_cml(client); + if (rv < 0 && (data->flags & PMBUS_READ_STATUS_AFTER_FAILED_CHECK)) + data->read_status(client, -1); pmbus_clear_fault_page(client, -1); return rv >= 0; } diff --git a/include/linux/pmbus.h b/include/linux/pmbus.h index 12cbbf305969..edd7c84fef65 100644 --- a/include/linux/pmbus.h +++ b/include/linux/pmbus.h @@ -43,6 +43,19 @@ */ #define PMBUS_NO_CAPABILITY BIT(2) +/* + * PMBUS_READ_STATUS_AFTER_FAILED_CHECK + * + * Some PMBus chips end up in an undefined state when trying to read an + * unsupported register. For such chips, it is necessary to reset the + * chip pmbus controller to a known state after a failed register check. + * This can be done by reading a known register. By setting this flag the + * driver will try to read the STATUS register after each failed + * register check. This read may fail, but it will put the chip in a + * known state. + */ +#define PMBUS_READ_STATUS_AFTER_FAILED_CHECK BIT(3) + struct pmbus_platform_data { u32 flags; /* Device specific flags */ |