target/linux/bcm27xx/patches-5.4/950-0819-media-i2c-imx290-fix-reset-GPIO-pin-handling.patch

   1 From 47f49370b3c1c7f4d4aae855966d2a3beef6c6d4 Mon Sep 17 00:00:00 2001
   2 From: Andrey Konovalov <andrey.konovalov@linaro.org>
   3 Date: Fri, 12 Jun 2020 15:53:48 +0200
   4 Subject: [PATCH] media: i2c: imx290: fix reset GPIO pin handling
   5
   6 Commit 3909a92d7df622b41b9ceeeea694e641cad7667b upstream.
   7
   8 According to https://www.kernel.org/doc/Documentation/gpio/consumer.txt,
   9
  10 - all of the gpiod_set_value_xxx() functions operate with the *logical*
  11 value. So in imx290_power_on() the reset signal should be cleared
  12 (de-asserted) with gpiod_set_value_cansleep(imx290->rst_gpio, 0), and in
  13 imx290_power_off() the value of 1 must be used to apply/assert the reset
  14 to the sensor. In the device tree the reset pin is described as
  15 GPIO_ACTIVE_LOW, and gpiod_set_value_xxx() functions take this into
  16 account,
  17
  18 - when devm_gpiod_get_optional() is called with GPIOD_ASIS, the GPIO is
  19 not initialized, and the direction must be set later; using a GPIO
  20 without setting its direction first is illegal and will result in undefined
  21 behavior. Fix this by using GPIOD_OUT_HIGH instead of GPIOD_ASIS (this
  22 asserts the reset signal to the sensor initially).
  23
  24 Signed-off-by: Andrey Konovalov <andrey.konovalov@linaro.org>
  25 Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
  26 Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
  27 Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
  28 ---
  29  drivers/media/i2c/imx290.c | 7 ++++---
  30  1 file changed, 4 insertions(+), 3 deletions(-)
  31
  32 --- a/drivers/media/i2c/imx290.c
  33 +++ b/drivers/media/i2c/imx290.c
  34 @@ -628,7 +628,7 @@ static int imx290_power_on(struct device
  35         }
  36
  37         usleep_range(1, 2);
  38 -       gpiod_set_value_cansleep(imx290->rst_gpio, 1);
  39 +       gpiod_set_value_cansleep(imx290->rst_gpio, 0);
  40         usleep_range(30000, 31000);
  41
  42         return 0;
  43 @@ -641,7 +641,7 @@ static int imx290_power_off(struct devic
  44         struct imx290 *imx290 = to_imx290(sd);
  45
  46         clk_disable_unprepare(imx290->xclk);
  47 -       gpiod_set_value_cansleep(imx290->rst_gpio, 0);
  48 +       gpiod_set_value_cansleep(imx290->rst_gpio, 1);
  49         regulator_bulk_disable(IMX290_NUM_SUPPLIES, imx290->supplies);
  50
  51         return 0;
  52 @@ -757,7 +757,8 @@ static int imx290_probe(struct i2c_clien
  53                 goto free_err;
  54         }
  55
  56 -       imx290->rst_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_ASIS);
  57 +       imx290->rst_gpio = devm_gpiod_get_optional(dev, "reset",
  58 +                                                  GPIOD_OUT_HIGH);
  59         if (IS_ERR(imx290->rst_gpio)) {
  60                 dev_err(dev, "Cannot get reset gpio\n");
  61                 ret = PTR_ERR(imx290->rst_gpio);