root/drivers/gpu/drm/omapdrm/dss/hdmi_common.c

DEFINITIONS

1. hdmi_parse_lanes_of
2. hdmi_compute_acr

   1 // SPDX-License-Identifier: GPL-2.0
   2 
   3 #define DSS_SUBSYS_NAME "HDMI"
   4 
   5 #include <linux/kernel.h>
   6 #include <linux/err.h>
   7 #include <linux/of.h>
   8 
   9 #include "omapdss.h"
  10 #include "hdmi.h"
  11 
  12 int hdmi_parse_lanes_of(struct platform_device *pdev, struct device_node *ep,
  13         struct hdmi_phy_data *phy)
  14 {
  15         struct property *prop;
  16         int r, len;
  17 
  18         prop = of_find_property(ep, "lanes", &len);
  19         if (prop) {
  20                 u32 lanes[8];
  21 
  22                 if (len / sizeof(u32) != ARRAY_SIZE(lanes)) {
  23                         dev_err(&pdev->dev, "bad number of lanes\n");
  24                         return -EINVAL;
  25                 }
  26 
  27                 r = of_property_read_u32_array(ep, "lanes", lanes,
  28                         ARRAY_SIZE(lanes));
  29                 if (r) {
  30                         dev_err(&pdev->dev, "failed to read lane data\n");
  31                         return r;
  32                 }
  33 
  34                 r = hdmi_phy_parse_lanes(phy, lanes);
  35                 if (r) {
  36                         dev_err(&pdev->dev, "failed to parse lane data\n");
  37                         return r;
  38                 }
  39         } else {
  40                 static const u32 default_lanes[] = { 0, 1, 2, 3, 4, 5, 6, 7 };
  41 
  42                 r = hdmi_phy_parse_lanes(phy, default_lanes);
  43                 if (WARN_ON(r)) {
  44                         dev_err(&pdev->dev, "failed to parse lane data\n");
  45                         return r;
  46                 }
  47         }
  48 
  49         return 0;
  50 }
  51 
  52 int hdmi_compute_acr(u32 pclk, u32 sample_freq, u32 *n, u32 *cts)
  53 {
  54         u32 deep_color;
  55         bool deep_color_correct = false;
  56 
  57         if (n == NULL || cts == NULL)
  58                 return -EINVAL;
  59 
  60         /* TODO: When implemented, query deep color mode here. */
  61         deep_color = 100;
  62 
  63         /*
  64          * When using deep color, the default N value (as in the HDMI
  65          * specification) yields to an non-integer CTS. Hence, we
  66          * modify it while keeping the restrictions described in
  67          * section 7.2.1 of the HDMI 1.4a specification.
  68          */
  69         switch (sample_freq) {
  70         case 32000:
  71         case 48000:
  72         case 96000:
  73         case 192000:
  74                 if (deep_color == 125)
  75                         if (pclk == 27027000 || pclk == 74250000)
  76                                 deep_color_correct = true;
  77                 if (deep_color == 150)
  78                         if (pclk == 27027000)
  79                                 deep_color_correct = true;
  80                 break;
  81         case 44100:
  82         case 88200:
  83         case 176400:
  84                 if (deep_color == 125)
  85                         if (pclk == 27027000)
  86                                 deep_color_correct = true;
  87                 break;
  88         default:
  89                 return -EINVAL;
  90         }
  91 
  92         if (deep_color_correct) {
  93                 switch (sample_freq) {
  94                 case 32000:
  95                         *n = 8192;
  96                         break;
  97                 case 44100:
  98                         *n = 12544;
  99                         break;
 100                 case 48000:
 101                         *n = 8192;
 102                         break;
 103                 case 88200:
 104                         *n = 25088;
 105                         break;
 106                 case 96000:
 107                         *n = 16384;
 108                         break;
 109                 case 176400:
 110                         *n = 50176;
 111                         break;
 112                 case 192000:
 113                         *n = 32768;
 114                         break;
 115                 default:
 116                         return -EINVAL;
 117                 }
 118         } else {
 119                 switch (sample_freq) {
 120                 case 32000:
 121                         *n = 4096;
 122                         break;
 123                 case 44100:
 124                         *n = 6272;
 125                         break;
 126                 case 48000:
 127                         *n = 6144;
 128                         break;
 129                 case 88200:
 130                         *n = 12544;
 131                         break;
 132                 case 96000:
 133                         *n = 12288;
 134                         break;
 135                 case 176400:
 136                         *n = 25088;
 137                         break;
 138                 case 192000:
 139                         *n = 24576;
 140                         break;
 141                 default:
 142                         return -EINVAL;
 143                 }
 144         }
 145         /* Calculate CTS. See HDMI 1.3a or 1.4a specifications */
 146         *cts = (pclk/1000) * (*n / 128) * deep_color / (sample_freq / 10);
 147 
 148         return 0;
 149 }