drivers/gpu/drm/sun4i/sun4i_rgb.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2015 Free Electrons
   4  * Copyright (C) 2015 NextThing Co
   5  *
   6  * Maxime Ripard <maxime.ripard@free-electrons.com>
   7  */
   8
   9 #include <linux/clk.h>
  10
  11 #include <drm/drm_atomic_helper.h>
  12 #include <drm/drm_bridge.h>
  13 #include <drm/drm_of.h>
  14 #include <drm/drm_panel.h>
  15 #include <drm/drm_print.h>
  16 #include <drm/drm_probe_helper.h>
  17 #include <drm/drm_simple_kms_helper.h>
  18
  19 #include "sun4i_crtc.h"
  20 #include "sun4i_tcon.h"
  21 #include "sun4i_rgb.h"
  22
  23 struct sun4i_rgb {
  24         struct drm_connector    connector;
  25         struct drm_encoder      encoder;
  26
  27         struct sun4i_tcon       *tcon;
  28         struct drm_panel        *panel;
  29         struct drm_bridge       *bridge;
  30 };
  31
  32 static inline struct sun4i_rgb *
  33 drm_connector_to_sun4i_rgb(struct drm_connector *connector)
  34 {
  35         return container_of(connector, struct sun4i_rgb,
  36                             connector);
  37 }
  38
  39 static inline struct sun4i_rgb *
  40 drm_encoder_to_sun4i_rgb(struct drm_encoder *encoder)
  41 {
  42         return container_of(encoder, struct sun4i_rgb,
  43                             encoder);
  44 }
  45
  46 static int sun4i_rgb_get_modes(struct drm_connector *connector)
  47 {
  48         struct sun4i_rgb *rgb =
  49                 drm_connector_to_sun4i_rgb(connector);
  50
  51         return drm_panel_get_modes(rgb->panel, connector);
  52 }
  53
  54 /*
  55  * VESA DMT defines a tolerance of 0.5% on the pixel clock, while the
  56  * CVT spec reuses that tolerance in its examples, so it looks to be a
  57  * good default tolerance for the EDID-based modes. Define it to 5 per
  58  * mille to avoid floating point operations.
  59  */
  60 #define SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE  5
  61
  62 static enum drm_mode_status sun4i_rgb_mode_valid(struct drm_encoder *crtc,
  63                                                  const struct drm_display_mode *mode)
  64 {
  65         struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(crtc);
  66         struct sun4i_tcon *tcon = rgb->tcon;
  67         u32 hsync = mode->hsync_end - mode->hsync_start;
  68         u32 vsync = mode->vsync_end - mode->vsync_start;
  69         unsigned long long rate = mode->clock * 1000;
  70         unsigned long long lowest, highest;
  71         unsigned long long rounded_rate;
  72
  73         DRM_DEBUG_DRIVER("Validating modes...\n");
  74
  75         if (hsync < 1)
  76                 return MODE_HSYNC_NARROW;
  77
  78         if (hsync > 0x3ff)
  79                 return MODE_HSYNC_WIDE;
  80
  81         if ((mode->hdisplay < 1) || (mode->htotal < 1))
  82                 return MODE_H_ILLEGAL;
  83
  84         if ((mode->hdisplay > 0x7ff) || (mode->htotal > 0xfff))
  85                 return MODE_BAD_HVALUE;
  86
  87         DRM_DEBUG_DRIVER("Horizontal parameters OK\n");
  88
  89         if (vsync < 1)
  90                 return MODE_VSYNC_NARROW;
  91
  92         if (vsync > 0x3ff)
  93                 return MODE_VSYNC_WIDE;
  94
  95         if ((mode->vdisplay < 1) || (mode->vtotal < 1))
  96                 return MODE_V_ILLEGAL;
  97
  98         if ((mode->vdisplay > 0x7ff) || (mode->vtotal > 0xfff))
  99                 return MODE_BAD_VVALUE;
 100
 101         DRM_DEBUG_DRIVER("Vertical parameters OK\n");
 102
 103         /*
 104          * TODO: We should use the struct display_timing if available
 105          * and / or trying to stretch the timings within that
 106          * tolerancy to take care of panels that we wouldn't be able
 107          * to have a exact match for.
 108          */
 109         if (rgb->panel) {
 110                 DRM_DEBUG_DRIVER("RGB panel used, skipping clock rate checks");
 111                 goto out;
 112         }
 113
 114         /*
 115          * That shouldn't ever happen unless something is really wrong, but it
 116          * doesn't harm to check.
 117          */
 118         if (!rgb->bridge)
 119                 goto out;
 120
 121         tcon->dclk_min_div = 6;
 122         tcon->dclk_max_div = 127;
 123         rounded_rate = clk_round_rate(tcon->dclk, rate);
 124
 125         lowest = rate * (1000 - SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE);
 126         do_div(lowest, 1000);
 127         if (rounded_rate < lowest)
 128                 return MODE_CLOCK_LOW;
 129
 130         highest = rate * (1000 + SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE);
 131         do_div(highest, 1000);
 132         if (rounded_rate > highest)
 133                 return MODE_CLOCK_HIGH;
 134
 135 out:
 136         DRM_DEBUG_DRIVER("Clock rate OK\n");
 137
 138         return MODE_OK;
 139 }
 140
 141 static const struct drm_connector_helper_funcs sun4i_rgb_con_helper_funcs = {
 142         .get_modes      = sun4i_rgb_get_modes,
 143 };
 144
 145 static void
 146 sun4i_rgb_connector_destroy(struct drm_connector *connector)
 147 {
 148         drm_connector_cleanup(connector);
 149 }
 150
 151 static const struct drm_connector_funcs sun4i_rgb_con_funcs = {
 152         .fill_modes             = drm_helper_probe_single_connector_modes,
 153         .destroy                = sun4i_rgb_connector_destroy,
 154         .reset                  = drm_atomic_helper_connector_reset,
 155         .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 156         .atomic_destroy_state   = drm_atomic_helper_connector_destroy_state,
 157 };
 158
 159 static void sun4i_rgb_encoder_enable(struct drm_encoder *encoder)
 160 {
 161         struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(encoder);
 162
 163         DRM_DEBUG_DRIVER("Enabling RGB output\n");
 164
 165         if (rgb->panel) {
 166                 drm_panel_prepare(rgb->panel);
 167                 drm_panel_enable(rgb->panel);
 168         }
 169 }
 170
 171 static void sun4i_rgb_encoder_disable(struct drm_encoder *encoder)
 172 {
 173         struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(encoder);
 174
 175         DRM_DEBUG_DRIVER("Disabling RGB output\n");
 176
 177         if (rgb->panel) {
 178                 drm_panel_disable(rgb->panel);
 179                 drm_panel_unprepare(rgb->panel);
 180         }
 181 }
 182
 183 static const struct drm_encoder_helper_funcs sun4i_rgb_enc_helper_funcs = {
 184         .disable        = sun4i_rgb_encoder_disable,
 185         .enable         = sun4i_rgb_encoder_enable,
 186         .mode_valid     = sun4i_rgb_mode_valid,
 187 };
 188
 189 int sun4i_rgb_init(struct drm_device *drm, struct sun4i_tcon *tcon)
 190 {
 191         struct drm_encoder *encoder;
 192         struct sun4i_rgb *rgb;
 193         int ret;
 194
 195         rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);
 196         if (!rgb)
 197                 return -ENOMEM;
 198         rgb->tcon = tcon;
 199         encoder = &rgb->encoder;
 200
 201         ret = drm_of_find_panel_or_bridge(tcon->dev->of_node, 1, 0,
 202                                           &rgb->panel, &rgb->bridge);
 203         if (ret) {
 204                 dev_info(drm->dev, "No panel or bridge found... RGB output disabled\n");
 205                 return 0;
 206         }
 207
 208         drm_encoder_helper_add(&rgb->encoder,
 209                                &sun4i_rgb_enc_helper_funcs);
 210         ret = drm_simple_encoder_init(drm, &rgb->encoder,
 211                                       DRM_MODE_ENCODER_NONE);
 212         if (ret) {
 213                 dev_err(drm->dev, "Couldn't initialise the rgb encoder\n");
 214                 goto err_out;
 215         }
 216
 217         /* The RGB encoder can only work with the TCON channel 0 */
 218         rgb->encoder.possible_crtcs = drm_crtc_mask(&tcon->crtc->crtc);
 219
 220         if (rgb->panel) {
 221                 drm_connector_helper_add(&rgb->connector,
 222                                          &sun4i_rgb_con_helper_funcs);
 223                 ret = drm_connector_init(drm, &rgb->connector,
 224                                          &sun4i_rgb_con_funcs,
 225                                          DRM_MODE_CONNECTOR_Unknown);
 226                 if (ret) {
 227                         dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
 228                         goto err_cleanup_connector;
 229                 }
 230
 231                 drm_connector_attach_encoder(&rgb->connector,
 232                                                   &rgb->encoder);
 233         }
 234
 235         if (rgb->bridge) {
 236                 ret = drm_bridge_attach(encoder, rgb->bridge, NULL, 0);
 237                 if (ret) {
 238                         dev_err(drm->dev, "Couldn't attach our bridge\n");
 239                         goto err_cleanup_connector;
 240                 }
 241         }
 242
 243         return 0;
 244
 245 err_cleanup_connector:
 246         drm_encoder_cleanup(&rgb->encoder);
 247 err_out:
 248         return ret;
 249 }
 250 EXPORT_SYMBOL(sun4i_rgb_init);