git.openwrt.org Git - openwrt/staging/linusw.git/blob

   1 From 6a0ae67b699bef301e835b814a416067567ecd39 Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Wed, 3 Apr 2024 16:06:08 +0100
   4 Subject: [PATCH 1039/1085] media: bcm2835-unicam: Add option for a GPIO to
   5  reflect FS/FE timing
   6
   7 The legacy stack had an option to have a GPIO track frame start and
   8 end events to give basic synchronisation to the incoming image stream.
   9 https://forums.raspberrypi.com/viewtopic.php?t=190314
  10
  11 Replicate this in the kernel Unicam driver.
  12
  13 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  14 ---
  15  drivers/media/platform/bcm2835/bcm2835-unicam.c | 12 ++++++++++++
  16  1 file changed, 12 insertions(+)
  17
  18 --- a/drivers/media/platform/bcm2835/bcm2835-unicam.c
  19 +++ b/drivers/media/platform/bcm2835/bcm2835-unicam.c
  20 @@ -49,6 +49,7 @@
  21  #include <linux/device.h>
  22  #include <linux/dma-mapping.h>
  23  #include <linux/err.h>
  24 +#include <linux/gpio/consumer.h>
  25  #include <linux/init.h>
  26  #include <linux/interrupt.h>
  27  #include <linux/io.h>
  28 @@ -543,6 +544,8 @@ struct unicam_device {
  29         struct v4l2_device v4l2_dev;
  30         struct media_device mdev;
  31
  32 +       struct gpio_desc *sync_gpio;
  33 +
  34         /* parent device */
  35         struct platform_device *pdev;
  36         /* subdevice async Notifier */
  37 @@ -943,6 +946,8 @@ static irqreturn_t unicam_isr(int irq, v
  38         if (fe) {
  39                 bool inc_seq = unicam->frame_started;
  40
  41 +               if (unicam->sync_gpio)
  42 +                       gpiod_set_value(unicam->sync_gpio, 0);
  43                 /*
  44                  * Ensure we have swapped buffers already as we can't
  45                  * stop the peripheral. If no buffer is available, use a
  46 @@ -1003,6 +1008,10 @@ static irqreturn_t unicam_isr(int irq, v
  47                  * aka frame start.
  48                  */
  49                 ts = ktime_get_ns();
  50 +
  51 +               if (unicam->sync_gpio)
  52 +                       gpiod_set_value(unicam->sync_gpio, 1);
  53 +
  54                 for (i = 0; i < ARRAY_SIZE(unicam->node); i++) {
  55                         if (!unicam->node[i].streaming)
  56                                 continue;
  57 @@ -3407,6 +3416,9 @@ static int unicam_probe(struct platform_
  58                 goto err_unicam_put;
  59         }
  60
  61 +       unicam->sync_gpio = devm_gpiod_get_optional(&pdev->dev, "sync",
  62 +                                                   GPIOD_OUT_LOW);
  63 +
  64         ret = platform_get_irq(pdev, 0);
  65         if (ret <= 0) {
  66                 dev_err(&pdev->dev, "No IRQ resource\n");