target/linux/brcm2708/patches-4.14/950-0323-ov5647-Add-support-for-PWDN-GPIO.patch

   1 From 34220db79008820c110473fe804cf02af3037889 Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.org>
   3 Date: Thu, 18 May 2017 15:42:34 +0100
   4 Subject: [PATCH 323/454] ov5647: Add support for PWDN GPIO.
   5
   6 Add support for an optional GPIO connected to PWDN on the sensor.
   7
   8 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
   9 ---
  10  drivers/media/i2c/ov5647.c | 28 ++++++++++++++++++++++++++++
  11  1 file changed, 28 insertions(+)
  12
  13 --- a/drivers/media/i2c/ov5647.c
  14 +++ b/drivers/media/i2c/ov5647.c
  15 @@ -21,6 +21,7 @@
  16
  17  #include <linux/clk.h>
  18  #include <linux/delay.h>
  19 +#include <linux/gpio/consumer.h>
  20  #include <linux/i2c.h>
  21  #include <linux/init.h>
  22  #include <linux/io.h>
  23 @@ -35,6 +36,13 @@
  24
  25  #define SENSOR_NAME "ov5647"
  26
  27 +/*
  28 + * From the datasheet, "20ms after PWDN goes low or 20ms after RESETB goes
  29 + * high if reset is inserted after PWDN goes high, host can access sensor's
  30 + * SCCB to initialize sensor."
  31 + */
  32 +#define PWDN_ACTIVE_DELAY_MS   20
  33 +
  34  #define OV5647_SW_RESET                0x0103
  35  #define OV5647_REG_CHIPID_H    0x300A
  36  #define OV5647_REG_CHIPID_L    0x300B
  37 @@ -77,6 +85,7 @@ struct ov5647 {
  38         unsigned int                    height;
  39         int                             power_count;
  40         struct clk                      *xclk;
  41 +       struct gpio_desc                *pwdn;
  42  };
  43
  44  static inline struct ov5647 *to_state(struct v4l2_subdev *sd)
  45 @@ -334,6 +343,11 @@ static int ov5647_sensor_power(struct v4
  46         if (on && !ov5647->power_count) {
  47                 dev_dbg(&client->dev, "OV5647 power on\n");
  48
  49 +               if (ov5647->pwdn) {
  50 +                       gpiod_set_value(ov5647->pwdn, 0);
  51 +                       msleep(PWDN_ACTIVE_DELAY_MS);
  52 +               }
  53 +
  54                 ret = clk_prepare_enable(ov5647->xclk);
  55                 if (ret < 0) {
  56                         dev_err(&client->dev, "clk prepare enable failed\n");
  57 @@ -371,6 +385,8 @@ static int ov5647_sensor_power(struct v4
  58                         dev_dbg(&client->dev, "soft stby failed\n");
  59
  60                 clk_disable_unprepare(ov5647->xclk);
  61 +
  62 +               gpiod_set_value(ov5647->pwdn, 1);
  63         }
  64
  65         /* Update the power count. */
  66 @@ -583,6 +599,10 @@ static int ov5647_probe(struct i2c_clien
  67                 return -EINVAL;
  68         }
  69
  70 +       /* Request the power down GPIO asserted */
  71 +       sensor->pwdn = devm_gpiod_get_optional(&client->dev, "pwdn",
  72 +                                              GPIOD_OUT_HIGH);
  73 +
  74         mutex_init(&sensor->lock);
  75
  76         sd = &sensor->sd;
  77 @@ -596,7 +616,15 @@ static int ov5647_probe(struct i2c_clien
  78         if (ret < 0)
  79                 goto mutex_remove;
  80
  81 +       if (sensor->pwdn) {
  82 +               gpiod_set_value(sensor->pwdn, 0);
  83 +               msleep(PWDN_ACTIVE_DELAY_MS);
  84 +       }
  85 +
  86         ret = ov5647_detect(sd);
  87 +
  88 +       gpiod_set_value(sensor->pwdn, 1);
  89 +
  90         if (ret < 0)
  91                 goto error;
  92