drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c

   1 /*
   2  * Copyright © 2016-2017 Broadcom
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * Portions of this file (derived from panel-simple.c) are:
   9  *
  10  * Copyright (C) 2013, NVIDIA Corporation.  All rights reserved.
  11  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a
  13  * copy of this software and associated documentation files (the "Software"),
  14  * to deal in the Software without restriction, including without limitation
  15  * the rights to use, copy, modify, merge, publish, distribute, sub license,
  16  * and/or sell copies of the Software, and to permit persons to whom the
  17  * Software is furnished to do so, subject to the following conditions:
  18  *
  19  * The above copyright notice and this permission notice (including the
  20  * next paragraph) shall be included in all copies or substantial portions
  21  * of the Software.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  24  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  25  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  26  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  27  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  28  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  29  * DEALINGS IN THE SOFTWARE.
  30  */
  31
  32 /*
  33  * Raspberry Pi 7" touchscreen panel driver.
  34  *
  35  * The 7" touchscreen consists of a DPI LCD panel, a Toshiba
  36  * TC358762XBG DSI-DPI bridge, and an I2C-connected Atmel ATTINY88-MUR
  37  * controlling power management, the LCD PWM, and initial register
  38  * setup of the Tohsiba.
  39  *
  40  * This driver controls the TC358762 and ATTINY88, presenting a DSI
  41  * device with a drm_panel.
  42  */
  43
  44 #include <linux/delay.h>
  45 #include <linux/err.h>
  46 #include <linux/i2c.h>
  47 #include <linux/media-bus-format.h>
  48 #include <linux/module.h>
  49 #include <linux/of.h>
  50 #include <linux/of_graph.h>
  51 #include <linux/pm.h>
  52
  53 #include <drm/drm_crtc.h>
  54 #include <drm/drm_device.h>
  55 #include <drm/drm_mipi_dsi.h>
  56 #include <drm/drm_panel.h>
  57
  58 #define RPI_DSI_DRIVER_NAME "rpi-ts-dsi"
  59
  60 /* I2C registers of the Atmel microcontroller. */
  61 enum REG_ADDR {
  62         REG_ID = 0x80,
  63         REG_PORTA, /* BIT(2) for horizontal flip, BIT(3) for vertical flip */
  64         REG_PORTB,
  65         REG_PORTC,
  66         REG_PORTD,
  67         REG_POWERON,
  68         REG_PWM,
  69         REG_DDRA,
  70         REG_DDRB,
  71         REG_DDRC,
  72         REG_DDRD,
  73         REG_TEST,
  74         REG_WR_ADDRL,
  75         REG_WR_ADDRH,
  76         REG_READH,
  77         REG_READL,
  78         REG_WRITEH,
  79         REG_WRITEL,
  80         REG_ID2,
  81 };
  82
  83 /* DSI D-PHY Layer Registers */
  84 #define D0W_DPHYCONTTX          0x0004
  85 #define CLW_DPHYCONTRX          0x0020
  86 #define D0W_DPHYCONTRX          0x0024
  87 #define D1W_DPHYCONTRX          0x0028
  88 #define COM_DPHYCONTRX          0x0038
  89 #define CLW_CNTRL               0x0040
  90 #define D0W_CNTRL               0x0044
  91 #define D1W_CNTRL               0x0048
  92 #define DFTMODE_CNTRL           0x0054
  93
  94 /* DSI PPI Layer Registers */
  95 #define PPI_STARTPPI            0x0104
  96 #define PPI_BUSYPPI             0x0108
  97 #define PPI_LINEINITCNT         0x0110
  98 #define PPI_LPTXTIMECNT         0x0114
  99 #define PPI_CLS_ATMR            0x0140
 100 #define PPI_D0S_ATMR            0x0144
 101 #define PPI_D1S_ATMR            0x0148
 102 #define PPI_D0S_CLRSIPOCOUNT    0x0164
 103 #define PPI_D1S_CLRSIPOCOUNT    0x0168
 104 #define CLS_PRE                 0x0180
 105 #define D0S_PRE                 0x0184
 106 #define D1S_PRE                 0x0188
 107 #define CLS_PREP                0x01A0
 108 #define D0S_PREP                0x01A4
 109 #define D1S_PREP                0x01A8
 110 #define CLS_ZERO                0x01C0
 111 #define D0S_ZERO                0x01C4
 112 #define D1S_ZERO                0x01C8
 113 #define PPI_CLRFLG              0x01E0
 114 #define PPI_CLRSIPO             0x01E4
 115 #define HSTIMEOUT               0x01F0
 116 #define HSTIMEOUTENABLE         0x01F4
 117
 118 /* DSI Protocol Layer Registers */
 119 #define DSI_STARTDSI            0x0204
 120 #define DSI_BUSYDSI             0x0208
 121 #define DSI_LANEENABLE          0x0210
 122 # define DSI_LANEENABLE_CLOCK           BIT(0)
 123 # define DSI_LANEENABLE_D0              BIT(1)
 124 # define DSI_LANEENABLE_D1              BIT(2)
 125
 126 #define DSI_LANESTATUS0         0x0214
 127 #define DSI_LANESTATUS1         0x0218
 128 #define DSI_INTSTATUS           0x0220
 129 #define DSI_INTMASK             0x0224
 130 #define DSI_INTCLR              0x0228
 131 #define DSI_LPTXTO              0x0230
 132 #define DSI_MODE                0x0260
 133 #define DSI_PAYLOAD0            0x0268
 134 #define DSI_PAYLOAD1            0x026C
 135 #define DSI_SHORTPKTDAT         0x0270
 136 #define DSI_SHORTPKTREQ         0x0274
 137 #define DSI_BTASTA              0x0278
 138 #define DSI_BTACLR              0x027C
 139
 140 /* DSI General Registers */
 141 #define DSIERRCNT               0x0300
 142 #define DSISIGMOD               0x0304
 143
 144 /* DSI Application Layer Registers */
 145 #define APLCTRL                 0x0400
 146 #define APLSTAT                 0x0404
 147 #define APLERR                  0x0408
 148 #define PWRMOD                  0x040C
 149 #define RDPKTLN                 0x0410
 150 #define PXLFMT                  0x0414
 151 #define MEMWRCMD                0x0418
 152
 153 /* LCDC/DPI Host Registers */
 154 #define LCDCTRL                 0x0420
 155 #define HSR                     0x0424
 156 #define HDISPR                  0x0428
 157 #define VSR                     0x042C
 158 #define VDISPR                  0x0430
 159 #define VFUEN                   0x0434
 160
 161 /* DBI-B Host Registers */
 162 #define DBIBCTRL                0x0440
 163
 164 /* SPI Master Registers */
 165 #define SPICMR                  0x0450
 166 #define SPITCR                  0x0454
 167
 168 /* System Controller Registers */
 169 #define SYSSTAT                 0x0460
 170 #define SYSCTRL                 0x0464
 171 #define SYSPLL1                 0x0468
 172 #define SYSPLL2                 0x046C
 173 #define SYSPLL3                 0x0470
 174 #define SYSPMCTRL               0x047C
 175
 176 /* GPIO Registers */
 177 #define GPIOC                   0x0480
 178 #define GPIOO                   0x0484
 179 #define GPIOI                   0x0488
 180
 181 /* I2C Registers */
 182 #define I2CCLKCTRL              0x0490
 183
 184 /* Chip/Rev Registers */
 185 #define IDREG                   0x04A0
 186
 187 /* Debug Registers */
 188 #define WCMDQUEUE               0x0500
 189 #define RCMDQUEUE               0x0504
 190
 191 struct rpi_touchscreen {
 192         struct drm_panel base;
 193         struct mipi_dsi_device *dsi;
 194         struct i2c_client *i2c;
 195 };
 196
 197 static const struct drm_display_mode rpi_touchscreen_modes[] = {
 198         {
 199                 /* Modeline comes from the Raspberry Pi firmware, with HFP=1
 200                  * plugged in and clock re-computed from that.
 201                  */
 202                 .clock = 25979400 / 1000,
 203                 .hdisplay = 800,
 204                 .hsync_start = 800 + 1,
 205                 .hsync_end = 800 + 1 + 2,
 206                 .htotal = 800 + 1 + 2 + 46,
 207                 .vdisplay = 480,
 208                 .vsync_start = 480 + 7,
 209                 .vsync_end = 480 + 7 + 2,
 210                 .vtotal = 480 + 7 + 2 + 21,
 211         },
 212 };
 213
 214 static struct rpi_touchscreen *panel_to_ts(struct drm_panel *panel)
 215 {
 216         return container_of(panel, struct rpi_touchscreen, base);
 217 }
 218
 219 static int rpi_touchscreen_i2c_read(struct rpi_touchscreen *ts, u8 reg)
 220 {
 221         return i2c_smbus_read_byte_data(ts->i2c, reg);
 222 }
 223
 224 static void rpi_touchscreen_i2c_write(struct rpi_touchscreen *ts,
 225                                       u8 reg, u8 val)
 226 {
 227         int ret;
 228
 229         ret = i2c_smbus_write_byte_data(ts->i2c, reg, val);
 230         if (ret)
 231                 dev_err(&ts->i2c->dev, "I2C write failed: %d\n", ret);
 232 }
 233
 234 static int rpi_touchscreen_write(struct rpi_touchscreen *ts, u16 reg, u32 val)
 235 {
 236         u8 msg[] = {
 237                 reg,
 238                 reg >> 8,
 239                 val,
 240                 val >> 8,
 241                 val >> 16,
 242                 val >> 24,
 243         };
 244
 245         mipi_dsi_generic_write(ts->dsi, msg, sizeof(msg));
 246
 247         return 0;
 248 }
 249
 250 static int rpi_touchscreen_disable(struct drm_panel *panel)
 251 {
 252         struct rpi_touchscreen *ts = panel_to_ts(panel);
 253
 254         rpi_touchscreen_i2c_write(ts, REG_PWM, 0);
 255
 256         rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
 257         udelay(1);
 258
 259         return 0;
 260 }
 261
 262 static int rpi_touchscreen_noop(struct drm_panel *panel)
 263 {
 264         return 0;
 265 }
 266
 267 static int rpi_touchscreen_prepare(struct drm_panel *panel)
 268 {
 269         struct rpi_touchscreen *ts = panel_to_ts(panel);
 270         int i;
 271
 272         rpi_touchscreen_i2c_write(ts, REG_POWERON, 1);
 273         /* Wait for nPWRDWN to go low to indicate poweron is done. */
 274         for (i = 0; i < 100; i++) {
 275                 if (rpi_touchscreen_i2c_read(ts, REG_PORTB) & 1)
 276                         break;
 277         }
 278
 279         rpi_touchscreen_write(ts, DSI_LANEENABLE,
 280                               DSI_LANEENABLE_CLOCK |
 281                               DSI_LANEENABLE_D0);
 282         rpi_touchscreen_write(ts, PPI_D0S_CLRSIPOCOUNT, 0x05);
 283         rpi_touchscreen_write(ts, PPI_D1S_CLRSIPOCOUNT, 0x05);
 284         rpi_touchscreen_write(ts, PPI_D0S_ATMR, 0x00);
 285         rpi_touchscreen_write(ts, PPI_D1S_ATMR, 0x00);
 286         rpi_touchscreen_write(ts, PPI_LPTXTIMECNT, 0x03);
 287
 288         rpi_touchscreen_write(ts, SPICMR, 0x00);
 289         rpi_touchscreen_write(ts, LCDCTRL, 0x00100150);
 290         rpi_touchscreen_write(ts, SYSCTRL, 0x040f);
 291         msleep(100);
 292
 293         rpi_touchscreen_write(ts, PPI_STARTPPI, 0x01);
 294         rpi_touchscreen_write(ts, DSI_STARTDSI, 0x01);
 295         msleep(100);
 296
 297         return 0;
 298 }
 299
 300 static int rpi_touchscreen_enable(struct drm_panel *panel)
 301 {
 302         struct rpi_touchscreen *ts = panel_to_ts(panel);
 303
 304         /* Turn on the backlight. */
 305         rpi_touchscreen_i2c_write(ts, REG_PWM, 255);
 306
 307         /* Default to the same orientation as the closed source
 308          * firmware used for the panel.  Runtime rotation
 309          * configuration will be supported using VC4's plane
 310          * orientation bits.
 311          */
 312         rpi_touchscreen_i2c_write(ts, REG_PORTA, BIT(2));
 313
 314         return 0;
 315 }
 316
 317 static int rpi_touchscreen_get_modes(struct drm_panel *panel,
 318                                      struct drm_connector *connector)
 319 {
 320         unsigned int i, num = 0;
 321         static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
 322
 323         for (i = 0; i < ARRAY_SIZE(rpi_touchscreen_modes); i++) {
 324                 const struct drm_display_mode *m = &rpi_touchscreen_modes[i];
 325                 struct drm_display_mode *mode;
 326
 327                 mode = drm_mode_duplicate(connector->dev, m);
 328                 if (!mode) {
 329                         dev_err(panel->dev, "failed to add mode %ux%u@%u\n",
 330                                 m->hdisplay, m->vdisplay,
 331                                 drm_mode_vrefresh(m));
 332                         continue;
 333                 }
 334
 335                 mode->type |= DRM_MODE_TYPE_DRIVER;
 336
 337                 if (i == 0)
 338                         mode->type |= DRM_MODE_TYPE_PREFERRED;
 339
 340                 drm_mode_set_name(mode);
 341
 342                 drm_mode_probed_add(connector, mode);
 343                 num++;
 344         }
 345
 346         connector->display_info.bpc = 8;
 347         connector->display_info.width_mm = 154;
 348         connector->display_info.height_mm = 86;
 349         drm_display_info_set_bus_formats(&connector->display_info,
 350                                          &bus_format, 1);
 351
 352         return num;
 353 }
 354
 355 static const struct drm_panel_funcs rpi_touchscreen_funcs = {
 356         .disable = rpi_touchscreen_disable,
 357         .unprepare = rpi_touchscreen_noop,
 358         .prepare = rpi_touchscreen_prepare,
 359         .enable = rpi_touchscreen_enable,
 360         .get_modes = rpi_touchscreen_get_modes,
 361 };
 362
 363 static int rpi_touchscreen_probe(struct i2c_client *i2c)
 364 {
 365         struct device *dev = &i2c->dev;
 366         struct rpi_touchscreen *ts;
 367         struct device_node *endpoint, *dsi_host_node;
 368         struct mipi_dsi_host *host;
 369         int ver;
 370         struct mipi_dsi_device_info info = {
 371                 .type = RPI_DSI_DRIVER_NAME,
 372                 .channel = 0,
 373                 .node = NULL,
 374         };
 375
 376         ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
 377         if (!ts)
 378                 return -ENOMEM;
 379
 380         i2c_set_clientdata(i2c, ts);
 381
 382         ts->i2c = i2c;
 383
 384         ver = rpi_touchscreen_i2c_read(ts, REG_ID);
 385         if (ver < 0) {
 386                 dev_err(dev, "Atmel I2C read failed: %d\n", ver);
 387                 return -ENODEV;
 388         }
 389
 390         switch (ver) {
 391         case 0xde: /* ver 1 */
 392         case 0xc3: /* ver 2 */
 393                 break;
 394         default:
 395                 dev_err(dev, "Unknown Atmel firmware revision: 0x%02x\n", ver);
 396                 return -ENODEV;
 397         }
 398
 399         /* Turn off at boot, so we can cleanly sequence powering on. */
 400         rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
 401
 402         /* Look up the DSI host.  It needs to probe before we do. */
 403         endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
 404         if (!endpoint)
 405                 return -ENODEV;
 406
 407         dsi_host_node = of_graph_get_remote_port_parent(endpoint);
 408         if (!dsi_host_node)
 409                 goto error;
 410
 411         host = of_find_mipi_dsi_host_by_node(dsi_host_node);
 412         of_node_put(dsi_host_node);
 413         if (!host) {
 414                 of_node_put(endpoint);
 415                 return -EPROBE_DEFER;
 416         }
 417
 418         info.node = of_graph_get_remote_port(endpoint);
 419         if (!info.node)
 420                 goto error;
 421
 422         of_node_put(endpoint);
 423
 424         ts->dsi = mipi_dsi_device_register_full(host, &info);
 425         if (IS_ERR(ts->dsi)) {
 426                 dev_err(dev, "DSI device registration failed: %ld\n",
 427                         PTR_ERR(ts->dsi));
 428                 return PTR_ERR(ts->dsi);
 429         }
 430
 431         drm_panel_init(&ts->base, dev, &rpi_touchscreen_funcs,
 432                        DRM_MODE_CONNECTOR_DSI);
 433
 434         /* This appears last, as it's what will unblock the DSI host
 435          * driver's component bind function.
 436          */
 437         drm_panel_add(&ts->base);
 438
 439         return 0;
 440
 441 error:
 442         of_node_put(endpoint);
 443         return -ENODEV;
 444 }
 445
 446 static void rpi_touchscreen_remove(struct i2c_client *i2c)
 447 {
 448         struct rpi_touchscreen *ts = i2c_get_clientdata(i2c);
 449
 450         mipi_dsi_detach(ts->dsi);
 451
 452         drm_panel_remove(&ts->base);
 453
 454         mipi_dsi_device_unregister(ts->dsi);
 455 }
 456
 457 static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi)
 458 {
 459         int ret;
 460
 461         dsi->mode_flags = (MIPI_DSI_MODE_VIDEO |
 462                            MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
 463                            MIPI_DSI_MODE_LPM);
 464         dsi->format = MIPI_DSI_FMT_RGB888;
 465         dsi->lanes = 1;
 466
 467         ret = mipi_dsi_attach(dsi);
 468
 469         if (ret)
 470                 dev_err(&dsi->dev, "failed to attach dsi to host: %d\n", ret);
 471
 472         return ret;
 473 }
 474
 475 static struct mipi_dsi_driver rpi_touchscreen_dsi_driver = {
 476         .driver.name = RPI_DSI_DRIVER_NAME,
 477         .probe = rpi_touchscreen_dsi_probe,
 478 };
 479
 480 static const struct of_device_id rpi_touchscreen_of_ids[] = {
 481         { .compatible = "raspberrypi,7inch-touchscreen-panel" },
 482         { } /* sentinel */
 483 };
 484 MODULE_DEVICE_TABLE(of, rpi_touchscreen_of_ids);
 485
 486 static struct i2c_driver rpi_touchscreen_driver = {
 487         .driver = {
 488                 .name = "rpi_touchscreen",
 489                 .of_match_table = rpi_touchscreen_of_ids,
 490         },
 491         .probe = rpi_touchscreen_probe,
 492         .remove = rpi_touchscreen_remove,
 493 };
 494
 495 static int __init rpi_touchscreen_init(void)
 496 {
 497         mipi_dsi_driver_register(&rpi_touchscreen_dsi_driver);
 498         return i2c_add_driver(&rpi_touchscreen_driver);
 499 }
 500 module_init(rpi_touchscreen_init);
 501
 502 static void __exit rpi_touchscreen_exit(void)
 503 {
 504         i2c_del_driver(&rpi_touchscreen_driver);
 505         mipi_dsi_driver_unregister(&rpi_touchscreen_dsi_driver);
 506 }
 507 module_exit(rpi_touchscreen_exit);
 508
 509 MODULE_AUTHOR("Eric Anholt <[email protected]>");
 510 MODULE_DESCRIPTION("Raspberry Pi 7-inch touchscreen driver");
 511 MODULE_LICENSE("GPL v2");