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media: i2c: imx500: GPIO acquire/release semantics

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When the imx500 driver is used as part of the 'AI Camera', the poweroff
state is never reached as the camera and gpio driver share a regulator.
By releasing the GPIOs when they are not in use, 'AI Camera' is able to
achieve a powered-down state.

Signed-off-by: Richard Oliver <richard.oliver@raspberrypi.com>
This commit is contained in:
Richard Oliver
2025-06-05 13:08:33 +01:00
parent 893915d5ce
commit 451e2c7286
1 changed files with 52 additions and 10 deletions
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62
drivers/media/i2c/imx500.c
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@@ -2360,9 +2360,11 @@ static int imx500_state_transition(struct imx500 *imx500, const u8 *fw,
}
/* Do SPI transfer */
gpiod_set_value_cansleep(imx500->led_gpio, 1);
if (imx500->led_gpio)
gpiod_set_value_cansleep(imx500->led_gpio, 1);
ret = imx500_spi_write(imx500, data, size);
gpiod_set_value_cansleep(imx500->led_gpio, 0);
if (imx500->led_gpio)
gpiod_set_value_cansleep(imx500->led_gpio, 0);
imx500->fw_progress += size;
@@ -2683,11 +2685,28 @@ static int imx500_power_on(struct device *dev)
struct imx500 *imx500 = to_imx500(sd);
int ret;
/* Acquire GPIOs first to ensure reset is asserted before power is applied */
imx500->led_gpio = devm_gpiod_get_optional(dev, "led", GPIOD_OUT_LOW);
if (IS_ERR(imx500->led_gpio)) {
ret = PTR_ERR(imx500->led_gpio);
dev_err(&client->dev, "%s: failed to get led gpio\n", __func__);
return ret;
}
imx500->reset_gpio =
devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
if (IS_ERR(imx500->reset_gpio)) {
ret = PTR_ERR(imx500->reset_gpio);
dev_err(&client->dev, "%s: failed to get reset gpio\n",
__func__);
goto gpio_led_put;
}
ret = regulator_bulk_enable(IMX500_NUM_SUPPLIES, imx500->supplies);
if (ret) {
dev_err(&client->dev, "%s: failed to enable regulators\n",
__func__);
return ret;
goto gpio_reset_put;
}
/* T4 - 1us
@@ -2707,7 +2726,8 @@ static int imx500_power_on(struct device *dev)
* as 0ms but also "XCLR pin should be set to 'High' after INCK supplied.".
* T4 and T5 are shown as overlapping.
*/
gpiod_set_value_cansleep(imx500->reset_gpio, 1);
if (imx500->reset_gpio)
gpiod_set_value_cansleep(imx500->reset_gpio, 1);
/* T7 - 9ms
* "INCK start and CXLR rising till Send Streaming Command wait time"
@@ -2718,6 +2738,16 @@ static int imx500_power_on(struct device *dev)
reg_off:
regulator_bulk_disable(IMX500_NUM_SUPPLIES, imx500->supplies);
gpio_reset_put:
if (imx500->reset_gpio) {
devm_gpiod_put(dev, imx500->reset_gpio);
imx500->reset_gpio = NULL;
}
gpio_led_put:
if (imx500->led_gpio) {
devm_gpiod_put(dev, imx500->led_gpio);
imx500->led_gpio = NULL;
}
return ret;
}
@@ -2734,7 +2764,19 @@ static int imx500_power_off(struct device *dev)
* Note, this is not the reverse order of power up.
*/
clk_disable_unprepare(imx500->xclk);
gpiod_set_value_cansleep(imx500->reset_gpio, 0);
if (imx500->reset_gpio)
gpiod_set_value_cansleep(imx500->reset_gpio, 0);
/* Release GPIOs before disabling regulators */
if (imx500->reset_gpio) {
devm_gpiod_put(&client->dev, imx500->reset_gpio);
imx500->reset_gpio = NULL;
}
if (imx500->led_gpio) {
devm_gpiod_put(&client->dev, imx500->led_gpio);
imx500->led_gpio = NULL;
}
regulator_bulk_disable(IMX500_NUM_SUPPLIES, imx500->supplies);
/* Force reprogramming of the common registers when powered up again. */
@@ -3052,14 +3094,14 @@ static int imx500_probe(struct i2c_client *client)
return ret;
}
imx500->led_gpio = devm_gpiod_get_optional(dev, "led", GPIOD_OUT_LOW);
imx500->reset_gpio =
devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
/* GPIOs are acquired in imx500_power_on() to avoid preventing
* regulator power down when shared with other drivers.
*/
/*
* The sensor must be powered for imx500_identify_module()
* to be able to read the CHIP_ID register
* to be able to read the CHIP_ID register. This also ensures
* GPIOs are available.
*/
ret = imx500_power_on(dev);
if (ret)