In certain use cases (where the chip is part of a camera module, and the
camera module is wired together with a camera privacy LED), powering on
the device during probe is undesirable. Add support for the at24 to
execute probe while being powered off. For this to happen, a hint in form
of a device property is required from the firmware.
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
drivers/misc/eeprom/at24.c | 30 ++++++++++++++++++++----------
1 file changed, 20 insertions(+), 10 deletions(-)
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 63aa541c96088..b9dbe5b6a97be 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -579,6 +579,7 @@ static int at24_probe(struct i2c_client *client)
bool i2c_fn_i2c, i2c_fn_block;
unsigned int i, num_addresses;
struct at24_data *at24;
+ bool powered_off;
struct regmap *regmap;
size_t at24_size;
bool writable;
@@ -701,19 +702,24 @@ static int at24_probe(struct i2c_client *client)
i2c_set_clientdata(client, at24);
- /* enable runtime pm */
- pm_runtime_set_active(dev);
+ powered_off = acpi_dev_powered_off_for_probe(&client->dev);
+ if (!powered_off)
+ pm_runtime_set_active(dev);
+
pm_runtime_enable(dev);
/*
- * Perform a one-byte test read to verify that the
- * chip is functional.
+ * Perform a one-byte test read to verify that the chip is functional,
+ * unless powering on the device is to be avoided during probe (i.e.
+ * it's powered off right now).
*/
- err = at24_read(at24, 0, &test_byte, 1);
- pm_runtime_idle(dev);
- if (err) {
- err = -ENODEV;
- goto err_clients;
+ if (!powered_off) {
+ err = at24_read(at24, 0, &test_byte, 1);
+ pm_runtime_idle(dev);
+ if (err) {
+ err = -ENODEV;
+ goto err_clients;
+ }
}
nvmem_config.name = dev_name(dev);
@@ -752,12 +758,15 @@ static int at24_probe(struct i2c_client *client)
static int at24_remove(struct i2c_client *client)
{
struct at24_data *at24;
+ bool powered_off;
at24 = i2c_get_clientdata(client);
at24_remove_dummy_clients(at24);
pm_runtime_disable(&client->dev);
- pm_runtime_set_suspended(&client->dev);
+ powered_off = acpi_dev_powered_off_for_probe(&client->dev);
+ if (!powered_off)
+ pm_runtime_set_suspended(&client->dev);
return 0;
}
@@ -765,6 +774,7 @@ static int at24_remove(struct i2c_client *client)
static struct i2c_driver at24_driver = {
.driver = {
.name = "at24",
+ .probe_powered_off = true,
.of_match_table = at24_of_match,
.acpi_match_table = ACPI_PTR(at24_acpi_ids),
},
--
2.11.0
