target/linux/brcm2708/patches-4.4/0292-drm-vc4-Respect-GPIO_ACTIVE_LOW-on-HDMI-HPD-if-set-i.patch

   1 From ce00fb0111a4b7c47dc301d7d4845736ee9bb493 Mon Sep 17 00:00:00 2001
   2 From: Eric Anholt <eric@anholt.net>
   3 Date: Mon, 29 Feb 2016 17:53:01 -0800
   4 Subject: [PATCH] drm/vc4: Respect GPIO_ACTIVE_LOW on HDMI HPD if set in the
   5  devicetree.
   6
   7 The original Raspberry Pi had the GPIO active high, but the later
   8 models are active low.  The DT GPIO bindings allow specifying the
   9 active flag, except that it doesn't get propagated to the gpiodesc, so
  10 you have to handle it yourself.
  11
  12 Signed-off-by: Eric Anholt <eric@anholt.net>
  13 Tested-by: Daniel Stone <daniels@collabora.com>
  14 (cherry picked from commit 0b06e0a7945130e6a187f7959529cba7725f573a)
  15 ---
  16  drivers/gpu/drm/vc4/vc4_hdmi.c | 12 ++++++++++--
  17  1 file changed, 10 insertions(+), 2 deletions(-)
  18
  19 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
  20 +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
  21 @@ -47,6 +47,7 @@ struct vc4_hdmi {
  22         void __iomem *hdmicore_regs;
  23         void __iomem *hd_regs;
  24         int hpd_gpio;
  25 +       bool hpd_active_low;
  26
  27         struct clk *pixel_clock;
  28         struct clk *hsm_clock;
  29 @@ -168,7 +169,8 @@ vc4_hdmi_connector_detect(struct drm_con
  30         return connector_status_connected;
  31
  32         if (vc4->hdmi->hpd_gpio) {
  33 -               if (gpio_get_value_cansleep(vc4->hdmi->hpd_gpio))
  34 +               if (gpio_get_value_cansleep(vc4->hdmi->hpd_gpio) ^
  35 +                   vc4->hdmi->hpd_active_low)
  36                         return connector_status_connected;
  37                 else
  38                         return connector_status_disconnected;
  39 @@ -519,11 +521,17 @@ static int vc4_hdmi_bind(struct device *
  40          * we'll use the HDMI core's register.
  41          */
  42         if (of_find_property(dev->of_node, "hpd-gpios", &value)) {
  43 -               hdmi->hpd_gpio = of_get_named_gpio(dev->of_node, "hpd-gpios", 0);
  44 +               enum of_gpio_flags hpd_gpio_flags;
  45 +
  46 +               hdmi->hpd_gpio = of_get_named_gpio_flags(dev->of_node,
  47 +                                                        "hpd-gpios", 0,
  48 +                                                        &hpd_gpio_flags);
  49                 if (hdmi->hpd_gpio < 0) {
  50                         ret = hdmi->hpd_gpio;
  51                         goto err_unprepare_hsm;
  52                 }
  53 +
  54 +               hdmi->hpd_active_low = hpd_gpio_flags & OF_GPIO_ACTIVE_LOW;
  55         }
  56
  57         vc4->hdmi = hdmi;