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_of.h>
  13 #include <drm/drm_panel.h>
  14 #include <drm/drm_print.h>
  15 #include <drm/drm_probe_helper.h>
  16
  17 #include "sun4i_crtc.h"
  18 #include "sun4i_tcon.h"
  19 #include "sun4i_rgb.h"
  20
  21 struct sun4i_rgb {
  22         struct drm_connector    connector;
  23         struct drm_encoder      encoder;
  24
  25         struct sun4i_tcon       *tcon;
  26         struct drm_panel        *panel;
  27         struct drm_bridge       *bridge;
  28 };
  29
  30 static inline struct sun4i_rgb *
  31 drm_connector_to_sun4i_rgb(struct drm_connector *connector)
  32 {
  33         return container_of(connector, struct sun4i_rgb,
  34                             connector);
  35 }
  36
  37 static inline struct sun4i_rgb *
  38 drm_encoder_to_sun4i_rgb(struct drm_encoder *encoder)
  39 {
  40         return container_of(encoder, struct sun4i_rgb,
  41                             encoder);
  42 }
  43
  44 static int sun4i_rgb_get_modes(struct drm_connector *connector)
  45 {
  46         struct sun4i_rgb *rgb =
  47                 drm_connector_to_sun4i_rgb(connector);
  48
  49         return drm_panel_get_modes(rgb->panel);
  50 }
  51
  52 /*
  53  * VESA DMT defines a tolerance of 0.5% on the pixel clock, while the
  54  * CVT spec reuses that tolerance in its examples, so it looks to be a
  55  * good default tolerance for the EDID-based modes. Define it to 5 per
  56  * mille to avoid floating point operations.
  57  */
  58 #define SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE  5
  59
  60 static enum drm_mode_status sun4i_rgb_mode_valid(struct drm_encoder *crtc,
  61                                                  const struct drm_display_mode *mode)
  62 {
  63         struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(crtc);
  64         struct sun4i_tcon *tcon = rgb->tcon;
  65         u32 hsync = mode->hsync_end - mode->hsync_start;
  66         u32 vsync = mode->vsync_end - mode->vsync_start;
  67         unsigned long long rate = mode->clock * 1000;
  68         unsigned long long lowest, highest;
  69         unsigned long long rounded_rate;
  70
  71         DRM_DEBUG_DRIVER("Validating modes...\n");
  72
  73         if (hsync < 1)
  74                 return MODE_HSYNC_NARROW;
  75
  76         if (hsync > 0x3ff)
  77                 return MODE_HSYNC_WIDE;
  78
  79         if ((mode->hdisplay < 1) || (mode->htotal < 1))
  80                 return MODE_H_ILLEGAL;
  81
  82         if ((mode->hdisplay > 0x7ff) || (mode->htotal > 0xfff))
  83                 return MODE_BAD_HVALUE;
  84
  85         DRM_DEBUG_DRIVER("Horizontal parameters OK\n");
  86
  87         if (vsync < 1)
  88                 return MODE_VSYNC_NARROW;
  89
  90         if (vsync > 0x3ff)
  91                 return MODE_VSYNC_WIDE;
  92
  93         if ((mode->vdisplay < 1) || (mode->vtotal < 1))
  94                 return MODE_V_ILLEGAL;
  95
  96         if ((mode->vdisplay > 0x7ff) || (mode->vtotal > 0xfff))
  97                 return MODE_BAD_VVALUE;
  98
  99         DRM_DEBUG_DRIVER("Vertical parameters OK\n");
 100
 101         /*
 102          * TODO: We should use the struct display_timing if available
 103          * and / or trying to stretch the timings within that
 104          * tolerancy to take care of panels that we wouldn't be able
 105          * to have a exact match for.
 106          */
 107         if (rgb->panel) {
 108                 DRM_DEBUG_DRIVER("RGB panel used, skipping clock rate checks");
 109                 goto out;
 110         }
 111
 112         /*
 113          * That shouldn't ever happen unless something is really wrong, but it
 114          * doesn't harm to check.
 115          */
 116         if (!rgb->bridge)
 117                 goto out;
 118
 119         tcon->dclk_min_div = 6;
 120         tcon->dclk_max_div = 127;
 121         rounded_rate = clk_round_rate(tcon->dclk, rate);
 122
 123         lowest = rate * (1000 - SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE);
 124         do_div(lowest, 1000);
 125         if (rounded_rate < lowest)
 126                 return MODE_CLOCK_LOW;
 127
 128         highest = rate * (1000 + SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE);
 129         do_div(highest, 1000);
 130         if (rounded_rate > highest)
 131                 return MODE_CLOCK_HIGH;
 132
 133 out:
 134         DRM_DEBUG_DRIVER("Clock rate OK\n");
 135
 136         return MODE_OK;
 137 }
 138
 139 static struct drm_connector_helper_funcs sun4i_rgb_con_helper_funcs = {
 140         .get_modes      = sun4i_rgb_get_modes,
 141 };
 142
 143 static void
 144 sun4i_rgb_connector_destroy(struct drm_connector *connector)
 145 {
 146         struct sun4i_rgb *rgb = drm_connector_to_sun4i_rgb(connector);
 147
 148         drm_panel_detach(rgb->panel);
 149         drm_connector_cleanup(connector);
 150 }
 151
 152 static const struct drm_connector_funcs sun4i_rgb_con_funcs = {
 153         .fill_modes             = drm_helper_probe_single_connector_modes,
 154         .destroy                = sun4i_rgb_connector_destroy,
 155         .reset                  = drm_atomic_helper_connector_reset,
 156         .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 157         .atomic_destroy_state   = drm_atomic_helper_connector_destroy_state,
 158 };
 159
 160 static void sun4i_rgb_encoder_enable(struct drm_encoder *encoder)
 161 {
 162         struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(encoder);
 163
 164         DRM_DEBUG_DRIVER("Enabling RGB output\n");
 165
 166         if (rgb->panel) {
 167                 drm_panel_prepare(rgb->panel);
 168                 drm_panel_enable(rgb->panel);
 169         }
 170 }
 171
 172 static void sun4i_rgb_encoder_disable(struct drm_encoder *encoder)
 173 {
 174         struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(encoder);
 175
 176         DRM_DEBUG_DRIVER("Disabling RGB output\n");
 177
 178         if (rgb->panel) {
 179                 drm_panel_disable(rgb->panel);
 180                 drm_panel_unprepare(rgb->panel);
 181         }
 182 }
 183
 184 static struct drm_encoder_helper_funcs sun4i_rgb_enc_helper_funcs = {
 185         .disable        = sun4i_rgb_encoder_disable,
 186         .enable         = sun4i_rgb_encoder_enable,
 187         .mode_valid     = sun4i_rgb_mode_valid,
 188 };
 189
 190 static void sun4i_rgb_enc_destroy(struct drm_encoder *encoder)
 191 {
 192         drm_encoder_cleanup(encoder);
 193 }
 194
 195 static struct drm_encoder_funcs sun4i_rgb_enc_funcs = {
 196         .destroy        = sun4i_rgb_enc_destroy,
 197 };
 198
 199 int sun4i_rgb_init(struct drm_device *drm, struct sun4i_tcon *tcon)
 200 {
 201         struct drm_encoder *encoder;
 202         struct sun4i_rgb *rgb;
 203         int ret;
 204
 205         rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);
 206         if (!rgb)
 207                 return -ENOMEM;
 208         rgb->tcon = tcon;
 209         encoder = &rgb->encoder;
 210
 211         ret = drm_of_find_panel_or_bridge(tcon->dev->of_node, 1, 0,
 212                                           &rgb->panel, &rgb->bridge);
 213         if (ret) {
 214                 dev_info(drm->dev, "No panel or bridge found... RGB output disabled\n");
 215                 return 0;
 216         }
 217
 218         drm_encoder_helper_add(&rgb->encoder,
 219                                &sun4i_rgb_enc_helper_funcs);
 220         ret = drm_encoder_init(drm,
 221                                &rgb->encoder,
 222                                &sun4i_rgb_enc_funcs,
 223                                DRM_MODE_ENCODER_NONE,
 224                                NULL);
 225         if (ret) {
 226                 dev_err(drm->dev, "Couldn't initialise the rgb encoder\n");
 227                 goto err_out;
 228         }
 229
 230         /* The RGB encoder can only work with the TCON channel 0 */
 231         rgb->encoder.possible_crtcs = drm_crtc_mask(&tcon->crtc->crtc);
 232
 233         if (rgb->panel) {
 234                 drm_connector_helper_add(&rgb->connector,
 235                                          &sun4i_rgb_con_helper_funcs);
 236                 ret = drm_connector_init(drm, &rgb->connector,
 237                                          &sun4i_rgb_con_funcs,
 238                                          DRM_MODE_CONNECTOR_Unknown);
 239                 if (ret) {
 240                         dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
 241                         goto err_cleanup_connector;
 242                 }
 243
 244                 drm_connector_attach_encoder(&rgb->connector,
 245                                                   &rgb->encoder);
 246
 247                 ret = drm_panel_attach(rgb->panel, &rgb->connector);
 248                 if (ret) {
 249                         dev_err(drm->dev, "Couldn't attach our panel\n");
 250                         goto err_cleanup_connector;
 251                 }
 252         }
 253
 254         if (rgb->bridge) {
 255                 ret = drm_bridge_attach(encoder, rgb->bridge, NULL);
 256                 if (ret) {
 257                         dev_err(drm->dev, "Couldn't attach our bridge\n");
 258                         goto err_cleanup_connector;
 259                 }
 260         }
 261
 262         return 0;
 263
 264 err_cleanup_connector:
 265         drm_encoder_cleanup(&rgb->encoder);
 266 err_out:
 267         return ret;
 268 }
 269 EXPORT_SYMBOL(sun4i_rgb_init);