linux/drivers/gpu/drm/sun4i/sun4i_rgb.c
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   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
  21struct 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
  30static inline struct sun4i_rgb *
  31drm_connector_to_sun4i_rgb(struct drm_connector *connector)
  32{
  33        return container_of(connector, struct sun4i_rgb,
  34                            connector);
  35}
  36
  37static inline struct sun4i_rgb *
  38drm_encoder_to_sun4i_rgb(struct drm_encoder *encoder)
  39{
  40        return container_of(encoder, struct sun4i_rgb,
  41                            encoder);
  42}
  43
  44static 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
  60static 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
 133out:
 134        DRM_DEBUG_DRIVER("Clock rate OK\n");
 135
 136        return MODE_OK;
 137}
 138
 139static struct drm_connector_helper_funcs sun4i_rgb_con_helper_funcs = {
 140        .get_modes      = sun4i_rgb_get_modes,
 141};
 142
 143static void
 144sun4i_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
 152static 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
 160static 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
 172static 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
 184static 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
 190static void sun4i_rgb_enc_destroy(struct drm_encoder *encoder)
 191{
 192        drm_encoder_cleanup(encoder);
 193}
 194
 195static struct drm_encoder_funcs sun4i_rgb_enc_funcs = {
 196        .destroy        = sun4i_rgb_enc_destroy,
 197};
 198
 199int 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
 264err_cleanup_connector:
 265        drm_encoder_cleanup(&rgb->encoder);
 266err_out:
 267        return ret;
 268}
 269EXPORT_SYMBOL(sun4i_rgb_init);
 270