target/linux/bcm27xx/patches-6.1/950-1013-drm-Look-for-an-alias-for-the-displays-to-use-as-the.patch

   1 From 3aa1f2477545ea6298bc6f2d7ffae68f090af9b8 Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Thu, 28 Sep 2023 18:27:09 +0100
   4 Subject: [PATCH] drm: Look for an alias for the displays to use as the DRM
   5  device name
   6
   7 Allow DT aliases of eg DSI2 to force make DRM allocate the
   8 display with the requested name.
   9
  10 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  11 ---
  12  drivers/gpu/drm/drm_connector.c | 60 ++++++++++++++++++++++++++++++---
  13  1 file changed, 56 insertions(+), 4 deletions(-)
  14
  15 --- a/drivers/gpu/drm/drm_connector.c
  16 +++ b/drivers/gpu/drm/drm_connector.c
  17 @@ -81,6 +81,7 @@ struct drm_conn_prop_enum_list {
  18         int type;
  19         const char *name;
  20         struct ida ida;
  21 +       int first_dyn_num;
  22  };
  23
  24  /*
  25 @@ -110,12 +111,41 @@ static struct drm_conn_prop_enum_list dr
  26         { DRM_MODE_CONNECTOR_USB, "USB" },
  27  };
  28
  29 +#define MAX_DT_NODE_NAME_LEN   20
  30 +#define DT_DRM_NODE_PREFIX     "drm_"
  31 +
  32 +static void drm_connector_get_of_name(int type, char *node_name, int length)
  33 +{
  34 +       int i = 0;
  35 +
  36 +       strcpy(node_name, DT_DRM_NODE_PREFIX);
  37 +
  38 +       do {
  39 +               node_name[i + strlen(DT_DRM_NODE_PREFIX)] =
  40 +                               tolower(drm_connector_enum_list[type].name[i]);
  41 +
  42 +       } while (drm_connector_enum_list[type].name[i++] &&
  43 +                i < length);
  44 +
  45 +       node_name[length - 1] = '\0';
  46 +}
  47 +
  48  void drm_connector_ida_init(void)
  49  {
  50 -       int i;
  51 +       int i, id;
  52 +       char node_name[MAX_DT_NODE_NAME_LEN];
  53
  54 -       for (i = 0; i < ARRAY_SIZE(drm_connector_enum_list); i++)
  55 +       for (i = 0; i < ARRAY_SIZE(drm_connector_enum_list); i++) {
  56                 ida_init(&drm_connector_enum_list[i].ida);
  57 +
  58 +               drm_connector_get_of_name(i, node_name, MAX_DT_NODE_NAME_LEN);
  59 +
  60 +               id = of_alias_get_highest_id(node_name);
  61 +               if (id > 0)
  62 +                       drm_connector_enum_list[i].first_dyn_num = id + 1;
  63 +               else
  64 +                       drm_connector_enum_list[i].first_dyn_num = 1;
  65 +       }
  66  }
  67
  68  void drm_connector_ida_destroy(void)
  69 @@ -222,7 +252,9 @@ static int __drm_connector_init(struct d
  70                                 struct i2c_adapter *ddc)
  71  {
  72         struct drm_mode_config *config = &dev->mode_config;
  73 +       char node_name[MAX_DT_NODE_NAME_LEN];
  74         int ret;
  75 +       int id;
  76         struct ida *connector_ida =
  77                 &drm_connector_enum_list[connector_type].ida;
  78
  79 @@ -252,8 +284,28 @@ static int __drm_connector_init(struct d
  80         ret = 0;
  81
  82         connector->connector_type = connector_type;
  83 -       connector->connector_type_id =
  84 -               ida_alloc_min(connector_ida, 1, GFP_KERNEL);
  85 +       connector->connector_type_id = 0;
  86 +
  87 +       drm_connector_get_of_name(connector_type, node_name, MAX_DT_NODE_NAME_LEN);
  88 +       id = of_alias_get_id(dev->dev->of_node, node_name);
  89 +       if (id > 0) {
  90 +               /* Try and allocate the requested ID
  91 +                * Valid range is 1 to 31, hence ignoring 0 as an error
  92 +                */
  93 +               int type_id = ida_alloc_range(connector_ida, id, id, GFP_KERNEL);
  94 +
  95 +               if (type_id > 0)
  96 +                       connector->connector_type_id = type_id;
  97 +               else
  98 +                       drm_err(dev, "Failed to acquire type ID %d for interface type %s, ret %d\n",
  99 +                               id, drm_connector_enum_list[connector_type].name,
 100 +                               type_id);
 101 +       }
 102 +       if (!connector->connector_type_id)
 103 +               connector->connector_type_id =
 104 +                               ida_alloc_min(connector_ida,
 105 +                                             drm_connector_enum_list[connector_type].first_dyn_num,
 106 +                                             GFP_KERNEL);
 107         if (connector->connector_type_id < 0) {
 108                 ret = connector->connector_type_id;
 109                 goto out_put_id;