[PATCH v2 8/9] regulator/rpi-panel-attiny: Don't read the LCD power status

Detlev Casanova
2022-01-21T15:22:00Z

The I2C to the Atmel is very fussy, and locks up easily on
Pi0-3 particularly on reads.

The LCD power status is controlled solely by this driver, so
rather than reading it back from the Atmel, use the cached
status last set.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
drivers/regulator/rpi-panel-attiny-regulator.c | 18 +-----------------
1 file changed, 1 insertion(+), 17 deletions(-)

diff --git a/drivers/regulator/rpi-panel-attiny-regulator.c b/drivers/regulator/rpi-panel-attiny-regulator.c
index 8090b9a485b5..8b80c0de1022 100644
--- a/drivers/regulator/rpi-panel-attiny-regulator.c
+++ b/drivers/regulator/rpi-panel-attiny-regulator.c
@@ -144,24 +144,8 @@ static int attiny_lcd_power_disable(struct regulator_dev *rdev)
static int attiny_lcd_power_is_enabled(struct regulator_dev *rdev)
{
struct attiny_lcd *state = rdev_get_drvdata(rdev);
- unsigned int data;
- int ret, i;
-
- mutex_lock(&state->lock);
-
- for (i = 0; i < 10; i++) {
- ret = regmap_read(rdev->regmap, REG_PORTC, &data);
- if (!ret)
- break;
- usleep_range(10000, 12000);
- }
-
- mutex_unlock(&state->lock);
-
- if (ret < 0)
- return ret;

- return data & PC_RST_BRIDGE_N;
+ return state->port_states[REG_PORTC - REG_PORTA] & PC_RST_BRIDGE_N;
}

static const struct regulator_init_data attiny_regulator_default = {
--
2.34.1