target/linux/brcm2708/patches-4.4/0444-drm-panel-Add-support-for-the-Raspberry-Pi-7-Touchsc.patch

   1 From 4557de6d23737cf44fa5ddf1379be59d4bca2df7 Mon Sep 17 00:00:00 2001
   2 From: Eric Anholt <eric@anholt.net>
   3 Date: Tue, 26 Apr 2016 13:46:13 -0700
   4 Subject: [PATCH] drm/panel: Add support for the Raspberry Pi 7" Touchscreen.
   5
   6 Signed-off-by: Eric Anholt <eric@anholt.net>
   7 ---
   8  drivers/gpu/drm/panel/Kconfig                      |   9 +
   9  drivers/gpu/drm/panel/Makefile                     |   1 +
  10  .../gpu/drm/panel/panel-raspberrypi-touchscreen.c  | 347 +++++++++++++++++++++
  11  3 files changed, 357 insertions(+)
  12  create mode 100644 drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
  13
  14 --- a/drivers/gpu/drm/panel/Kconfig
  15 +++ b/drivers/gpu/drm/panel/Kconfig
  16 @@ -31,6 +31,15 @@ config DRM_PANEL_LG_LG4573
  17           Say Y here if you want to enable support for LG4573 RGB panel.
  18           To compile this driver as a module, choose M here.
  19
  20 +config DRM_PANEL_RASPBERRYPI_TOUCHSCREEN
  21 +       tristate "Raspberry Pi 7-inch touchscreen panel"
  22 +       depends on DRM_MIPI_DSI
  23 +       depends on BACKLIGHT_CLASS_DEVICE
  24 +       help
  25 +         Say Y here if you want to enable support for the Raspberry
  26 +         Pi 7" Touchscreen.  To compile this driver as a module,
  27 +         choose M here.
  28 +
  29  config DRM_PANEL_SAMSUNG_S6E8AA0
  30         tristate "Samsung S6E8AA0 DSI video mode panel"
  31         depends on OF
  32 --- a/drivers/gpu/drm/panel/Makefile
  33 +++ b/drivers/gpu/drm/panel/Makefile
  34 @@ -1,5 +1,6 @@
  35  obj-$(CONFIG_DRM_PANEL_SIMPLE) += panel-simple.o
  36  obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
  37 +obj-$(CONFIG_DRM_PANEL_RASPBERRYPI_TOUCHSCREEN) += panel-raspberrypi-touchscreen.o
  38  obj-$(CONFIG_DRM_PANEL_SAMSUNG_LD9040) += panel-samsung-ld9040.o
  39  obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0) += panel-samsung-s6e8aa0.o
  40  obj-$(CONFIG_DRM_PANEL_SHARP_LQ101R1SX01) += panel-sharp-lq101r1sx01.o
  41 --- /dev/null
  42 +++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
  43 @@ -0,0 +1,347 @@
  44 +/*
  45 + * Copyright © 2016 Broadcom Limited
  46 + *
  47 + * This program is free software; you can redistribute it and/or modify
  48 + * it under the terms of the GNU General Public License version 2 as
  49 + * published by the Free Software Foundation.
  50 + *
  51 + * Portions of this file (derived from panel-simple.c) are:
  52 + *
  53 + * Copyright (C) 2013, NVIDIA Corporation.  All rights reserved.
  54 + *
  55 + * Permission is hereby granted, free of charge, to any person obtaining a
  56 + * copy of this software and associated documentation files (the "Software"),
  57 + * to deal in the Software without restriction, including without limitation
  58 + * the rights to use, copy, modify, merge, publish, distribute, sub license,
  59 + * and/or sell copies of the Software, and to permit persons to whom the
  60 + * Software is furnished to do so, subject to the following conditions:
  61 + *
  62 + * The above copyright notice and this permission notice (including the
  63 + * next paragraph) shall be included in all copies or substantial portions
  64 + * of the Software.
  65 + *
  66 + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  67 + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  68 + * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  69 + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  70 + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  71 + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  72 + * DEALINGS IN THE SOFTWARE.
  73 + */
  74 +
  75 +/**
  76 + * DOC: Raspberry Pi 7" touchscreen panel driver.
  77 + *
  78 + * The 7" touchscreen consists of a DPI LCD panel, a Toshiba
  79 + * TC358762XBG DSI-DPI bridge, and an I2C-connected Atmel ATTINY88-MUR
  80 + * controlling power management, the LCD PWM, and the touchscreen.
  81 + *
  82 + * This driver presents this device as a MIPI DSI panel to the DRM
  83 + * driver, and should expose the touchscreen as a HID device.
  84 + */
  85 +
  86 +#include <linux/backlight.h>
  87 +#include <linux/delay.h>
  88 +#include <linux/err.h>
  89 +#include <linux/fb.h>
  90 +#include <linux/gpio.h>
  91 +#include <linux/gpio/consumer.h>
  92 +#include <linux/i2c.h>
  93 +#include <linux/module.h>
  94 +#include <linux/of.h>
  95 +#include <linux/of_device.h>
  96 +#include <linux/of_graph.h>
  97 +#include <linux/pm.h>
  98 +
  99 +#include <drm/drm_panel.h>
 100 +#include <drm/drmP.h>
 101 +#include <drm/drm_crtc.h>
 102 +#include <drm/drm_mipi_dsi.h>
 103 +#include <drm/drm_panel.h>
 104 +
 105 +struct rpi_touchscreen {
 106 +       struct drm_panel base;
 107 +       struct mipi_dsi_device *dsi;
 108 +       struct i2c_client *bridge_i2c;
 109 +       struct backlight_device *backlight;
 110 +
 111 +       bool prepared;
 112 +       bool enabled;
 113 +
 114 +       /* Version of the firmware on the bridge chip */
 115 +       int atmel_ver;
 116 +};
 117 +
 118 +static const struct drm_display_mode rpi_touchscreen_modes[] = {
 119 +       {
 120 +               /* This is assuming that we'll be running the DSI PLL
 121 +                * at 2Ghz / 3 (since we only get integer dividers),
 122 +                * so a pixel clock of 2Ghz / 3 / 8.
 123 +                */
 124 +               .clock = 83333,
 125 +               .hdisplay = 800,
 126 +               .hsync_start = 800 + 61,
 127 +               .hsync_end = 800 + 61 + 2,
 128 +               .htotal = 800 + 61 + 2 + 44,
 129 +               .vdisplay = 480,
 130 +               .vsync_start = 480 + 7,
 131 +               .vsync_end = 480 + 7 + 2,
 132 +               .vtotal = 480 + 7 + 2 + 21,
 133 +               .vrefresh = 60,
 134 +       },
 135 +};
 136 +
 137 +static struct rpi_touchscreen *panel_to_ts(struct drm_panel *panel)
 138 +{
 139 +       return container_of(panel, struct rpi_touchscreen, base);
 140 +}
 141 +
 142 +struct regdump {
 143 +       const char *reg;
 144 +       u32 offset;
 145 +};
 146 +
 147 +#define REGDUMP(reg) { #reg, reg }
 148 +
 149 +static int rpi_touchscreen_disable(struct drm_panel *panel)
 150 +{
 151 +       struct rpi_touchscreen *ts = panel_to_ts(panel);
 152 +       pr_err("disable\n");
 153 +
 154 +       if (!ts->enabled)
 155 +               return 0;
 156 +
 157 +       if (ts->backlight) {
 158 +               ts->backlight->props.power = FB_BLANK_POWERDOWN;
 159 +               backlight_update_status(ts->backlight);
 160 +       }
 161 +
 162 +       ts->enabled = false;
 163 +
 164 +       return 0;
 165 +}
 166 +
 167 +static int rpi_touchscreen_unprepare(struct drm_panel *panel)
 168 +{
 169 +       struct rpi_touchscreen *ts = panel_to_ts(panel);
 170 +
 171 +       if (!ts->prepared)
 172 +               return 0;
 173 +
 174 +       ts->prepared = false;
 175 +
 176 +       return 0;
 177 +}
 178 +
 179 +static int rpi_touchscreen_prepare(struct drm_panel *panel)
 180 +{
 181 +       struct rpi_touchscreen *ts = panel_to_ts(panel);
 182 +
 183 +       if (ts->prepared)
 184 +               return 0;
 185 +
 186 +       ts->prepared = true;
 187 +
 188 +       return 0;
 189 +}
 190 +
 191 +/*
 192 + * Powers on the panel once the DSI link is up.
 193 + *
 194 + * The TC358762 is run in PLLOFF mode, where it usees the MIPI DSI
 195 + * byte clock instead of an external reference clock.  This means that
 196 + * we need the DSI host to be on and transmitting before we start
 197 + * talking to it.
 198 + */
 199 +static int rpi_touchscreen_enable(struct drm_panel *panel)
 200 +{
 201 +       struct rpi_touchscreen *ts = panel_to_ts(panel);
 202 +
 203 +       if (ts->enabled)
 204 +               return 0;
 205 +
 206 +       if (ts->backlight) {
 207 +               ts->backlight->props.power = FB_BLANK_UNBLANK;
 208 +               backlight_update_status(ts->backlight);
 209 +       }
 210 +
 211 +       ts->enabled = true;
 212 +
 213 +       return 0;
 214 +}
 215 +
 216 +static int rpi_touchscreen_get_modes(struct drm_panel *panel)
 217 +{
 218 +       struct drm_connector *connector = panel->connector;
 219 +       struct drm_device *drm = panel->drm;
 220 +       unsigned int i, num = 0;
 221 +
 222 +       for (i = 0; i < ARRAY_SIZE(rpi_touchscreen_modes); i++) {
 223 +               const struct drm_display_mode *m = &rpi_touchscreen_modes[i];
 224 +               struct drm_display_mode *mode;
 225 +
 226 +               mode = drm_mode_duplicate(drm, m);
 227 +               if (!mode) {
 228 +                       dev_err(drm->dev, "failed to add mode %ux%u@%u\n",
 229 +                               m->hdisplay, m->vdisplay, m->vrefresh);
 230 +                       continue;
 231 +               }
 232 +
 233 +               mode->type |= DRM_MODE_TYPE_DRIVER;
 234 +
 235 +               if (i == 0)
 236 +                       mode->type |= DRM_MODE_TYPE_PREFERRED;
 237 +
 238 +               drm_mode_set_name(mode);
 239 +
 240 +               drm_mode_probed_add(connector, mode);
 241 +               num++;
 242 +       }
 243 +
 244 +       connector->display_info.bpc = 8;
 245 +       connector->display_info.width_mm = 217; /* XXX */
 246 +       connector->display_info.height_mm = 136; /* XXX */
 247 +
 248 +       return num;
 249 +}
 250 +
 251 +static int rpi_touchscreen_backlight_update(struct backlight_device *bl)
 252 +{
 253 +       int brightness = bl->props.brightness;
 254 +
 255 +       if (bl->props.power != FB_BLANK_UNBLANK ||
 256 +           bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
 257 +               brightness = 0;
 258 +
 259 +       return 0;
 260 +}
 261 +
 262 +static const struct backlight_ops rpi_touchscreen_backlight_ops = {
 263 +       .update_status  = rpi_touchscreen_backlight_update,
 264 +};
 265 +
 266 +static const struct drm_panel_funcs rpi_touchscreen_funcs = {
 267 +       .disable = rpi_touchscreen_disable,
 268 +       .unprepare = rpi_touchscreen_unprepare,
 269 +       .prepare = rpi_touchscreen_prepare,
 270 +       .enable = rpi_touchscreen_enable,
 271 +       .get_modes = rpi_touchscreen_get_modes,
 272 +};
 273 +
 274 +static struct i2c_client *rpi_touchscreen_get_i2c(struct device *dev,
 275 +                                                 const char *name)
 276 +{
 277 +       struct device_node *node;
 278 +       struct i2c_client *client;
 279 +
 280 +       node = of_parse_phandle(dev->of_node, name, 0);
 281 +       if (!node)
 282 +               return ERR_PTR(-ENODEV);
 283 +
 284 +       client = of_find_i2c_device_by_node(node);
 285 +
 286 +       of_node_put(node);
 287 +
 288 +       return client;
 289 +}
 290 +
 291 +static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi)
 292 +{
 293 +       struct device *dev = &dsi->dev;
 294 +       struct rpi_touchscreen *ts;
 295 +       int ret;
 296 +
 297 +       ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
 298 +       if (!ts)
 299 +               return -ENOMEM;
 300 +
 301 +       dev_set_drvdata(dev, ts);
 302 +
 303 +       ts->dsi = dsi;
 304 +       dsi->mode_flags = (MIPI_DSI_MODE_VIDEO |
 305 +                          MIPI_DSI_MODE_VIDEO_SYNC_PULSE);
 306 +       dsi->format = MIPI_DSI_FMT_RGB888;
 307 +       dsi->lanes = 1;
 308 +
 309 +       ts->bridge_i2c =
 310 +               rpi_touchscreen_get_i2c(dev, "raspberrypi,touchscreen-bridge");
 311 +       if (!ts->bridge_i2c) {
 312 +               ret = -EPROBE_DEFER;
 313 +               return ret;
 314 +       }
 315 +
 316 +#if 0
 317 +       ts->backlight =
 318 +               devm_backlight_device_register(dev,
 319 +                                              "raspberrypi-touchscreen-backlight",
 320 +                                              dev, ts,
 321 +                                              &rpi_touchscreen_backlight_ops,
 322 +                                              NULL);
 323 +       if (IS_ERR(ts->backlight)) {
 324 +               DRM_ERROR("failed to register backlight\n");
 325 +               return PTR_ERR(ts->backlight);
 326 +       }
 327 +       ts->backlight->props.max_brightness = RPI_TOUCHSCREEN_MAX_BRIGHTNESS;
 328 +       ts->backlight->props.brightness = RPI_TOUCHSCREEN_MAX_BRIGHTNESS;
 329 +#endif
 330 +
 331 +       drm_panel_init(&ts->base);
 332 +       ts->base.dev = dev;
 333 +       ts->base.funcs = &rpi_touchscreen_funcs;
 334 +
 335 +       ret = drm_panel_add(&ts->base);
 336 +       if (ret < 0)
 337 +               goto err_release_bridge;
 338 +
 339 +       return mipi_dsi_attach(dsi);
 340 +
 341 +err_release_bridge:
 342 +       put_device(&ts->bridge_i2c->dev);
 343 +       return ret;
 344 +}
 345 +
 346 +static int rpi_touchscreen_dsi_remove(struct mipi_dsi_device *dsi)
 347 +{
 348 +       struct device *dev = &dsi->dev;
 349 +       struct rpi_touchscreen *ts = dev_get_drvdata(dev);
 350 +       int ret;
 351 +
 352 +       ret = mipi_dsi_detach(dsi);
 353 +       if (ret < 0) {
 354 +               dev_err(&dsi->dev, "failed to detach from DSI host: %d\n", ret);
 355 +               return ret;
 356 +       }
 357 +
 358 +       drm_panel_detach(&ts->base);
 359 +       drm_panel_remove(&ts->base);
 360 +
 361 +       put_device(&ts->bridge_i2c->dev);
 362 +
 363 +       return 0;
 364 +}
 365 +
 366 +static void rpi_touchscreen_dsi_shutdown(struct mipi_dsi_device *dsi)
 367 +{
 368 +       /* XXX: poweroff */
 369 +}
 370 +
 371 +static const struct of_device_id rpi_touchscreen_of_match[] = {
 372 +       { .compatible = "raspberrypi,touchscreen" },
 373 +       { } /* sentinel */
 374 +};
 375 +MODULE_DEVICE_TABLE(of, rpi_touchscreen_of_match);
 376 +
 377 +static struct mipi_dsi_driver rpi_touchscreen_driver = {
 378 +       .driver = {
 379 +               .name = "raspberrypi-touchscreen",
 380 +               .of_match_table = rpi_touchscreen_of_match,
 381 +       },
 382 +       .probe = rpi_touchscreen_dsi_probe,
 383 +       .remove = rpi_touchscreen_dsi_remove,
 384 +       .shutdown = rpi_touchscreen_dsi_shutdown,
 385 +};
 386 +module_mipi_dsi_driver(rpi_touchscreen_driver);
 387 +
 388 +MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
 389 +MODULE_DESCRIPTION("Raspberry Pi 7-inch touchscreen driver");
 390 +MODULE_LICENSE("GPL v2");