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/fb.h>
  47 #include <linux/gpio.h>
  48 #include <linux/gpio/consumer.h>
  49 #include <linux/i2c.h>
  50 #include <linux/module.h>
  51 #include <linux/of.h>
  52 #include <linux/of_device.h>
  53 #include <linux/of_graph.h>
  54 #include <linux/pm.h>
  55
  56 #include <drm/drm_panel.h>
  57 #include <drm/drmP.h>
  58 #include <drm/drm_crtc.h>
  59 #include <drm/drm_mipi_dsi.h>
  60 #include <drm/drm_panel.h>
  61
  62 #define RPI_DSI_DRIVER_NAME "rpi-ts-dsi"
  63
  64 /* I2C registers of the Atmel microcontroller. */
  65 enum REG_ADDR {
  66         REG_ID = 0x80,
  67         REG_PORTA, /* BIT(2) for horizontal flip, BIT(3) for vertical flip */
  68         REG_PORTB,
  69         REG_PORTC,
  70         REG_PORTD,
  71         REG_POWERON,
  72         REG_PWM,
  73         REG_DDRA,
  74         REG_DDRB,
  75         REG_DDRC,
  76         REG_DDRD,
  77         REG_TEST,
  78         REG_WR_ADDRL,
  79         REG_WR_ADDRH,
  80         REG_READH,
  81         REG_READL,
  82         REG_WRITEH,
  83         REG_WRITEL,
  84         REG_ID2,
  85 };
  86
  87 /* DSI D-PHY Layer Registers */
  88 #define D0W_DPHYCONTTX          0x0004
  89 #define CLW_DPHYCONTRX          0x0020
  90 #define D0W_DPHYCONTRX          0x0024
  91 #define D1W_DPHYCONTRX          0x0028
  92 #define COM_DPHYCONTRX          0x0038
  93 #define CLW_CNTRL               0x0040
  94 #define D0W_CNTRL               0x0044
  95 #define D1W_CNTRL               0x0048
  96 #define DFTMODE_CNTRL           0x0054
  97
  98 /* DSI PPI Layer Registers */
  99 #define PPI_STARTPPI            0x0104
 100 #define PPI_BUSYPPI             0x0108
 101 #define PPI_LINEINITCNT         0x0110
 102 #define PPI_LPTXTIMECNT         0x0114
 103 #define PPI_CLS_ATMR            0x0140
 104 #define PPI_D0S_ATMR            0x0144
 105 #define PPI_D1S_ATMR            0x0148
 106 #define PPI_D0S_CLRSIPOCOUNT    0x0164
 107 #define PPI_D1S_CLRSIPOCOUNT    0x0168
 108 #define CLS_PRE                 0x0180
 109 #define D0S_PRE                 0x0184
 110 #define D1S_PRE                 0x0188
 111 #define CLS_PREP                0x01A0
 112 #define D0S_PREP                0x01A4
 113 #define D1S_PREP                0x01A8
 114 #define CLS_ZERO                0x01C0
 115 #define D0S_ZERO                0x01C4
 116 #define D1S_ZERO                0x01C8
 117 #define PPI_CLRFLG              0x01E0
 118 #define PPI_CLRSIPO             0x01E4
 119 #define HSTIMEOUT               0x01F0
 120 #define HSTIMEOUTENABLE         0x01F4
 121
 122 /* DSI Protocol Layer Registers */
 123 #define DSI_STARTDSI            0x0204
 124 #define DSI_BUSYDSI             0x0208
 125 #define DSI_LANEENABLE          0x0210
 126 # define DSI_LANEENABLE_CLOCK           BIT(0)
 127 # define DSI_LANEENABLE_D0              BIT(1)
 128 # define DSI_LANEENABLE_D1              BIT(2)
 129
 130 #define DSI_LANESTATUS0         0x0214
 131 #define DSI_LANESTATUS1         0x0218
 132 #define DSI_INTSTATUS           0x0220
 133 #define DSI_INTMASK             0x0224
 134 #define DSI_INTCLR              0x0228
 135 #define DSI_LPTXTO              0x0230
 136 #define DSI_MODE                0x0260
 137 #define DSI_PAYLOAD0            0x0268
 138 #define DSI_PAYLOAD1            0x026C
 139 #define DSI_SHORTPKTDAT         0x0270
 140 #define DSI_SHORTPKTREQ         0x0274
 141 #define DSI_BTASTA              0x0278
 142 #define DSI_BTACLR              0x027C
 143
 144 /* DSI General Registers */
 145 #define DSIERRCNT               0x0300
 146 #define DSISIGMOD               0x0304
 147
 148 /* DSI Application Layer Registers */
 149 #define APLCTRL                 0x0400
 150 #define APLSTAT                 0x0404
 151 #define APLERR                  0x0408
 152 #define PWRMOD                  0x040C
 153 #define RDPKTLN                 0x0410
 154 #define PXLFMT                  0x0414
 155 #define MEMWRCMD                0x0418
 156
 157 /* LCDC/DPI Host Registers */
 158 #define LCDCTRL                 0x0420
 159 #define HSR                     0x0424
 160 #define HDISPR                  0x0428
 161 #define VSR                     0x042C
 162 #define VDISPR                  0x0430
 163 #define VFUEN                   0x0434
 164
 165 /* DBI-B Host Registers */
 166 #define DBIBCTRL                0x0440
 167
 168 /* SPI Master Registers */
 169 #define SPICMR                  0x0450
 170 #define SPITCR                  0x0454
 171
 172 /* System Controller Registers */
 173 #define SYSSTAT                 0x0460
 174 #define SYSCTRL                 0x0464
 175 #define SYSPLL1                 0x0468
 176 #define SYSPLL2                 0x046C
 177 #define SYSPLL3                 0x0470
 178 #define SYSPMCTRL               0x047C
 179
 180 /* GPIO Registers */
 181 #define GPIOC                   0x0480
 182 #define GPIOO                   0x0484
 183 #define GPIOI                   0x0488
 184
 185 /* I2C Registers */
 186 #define I2CCLKCTRL              0x0490
 187
 188 /* Chip/Rev Registers */
 189 #define IDREG                   0x04A0
 190
 191 /* Debug Registers */
 192 #define WCMDQUEUE               0x0500
 193 #define RCMDQUEUE               0x0504
 194
 195 struct rpi_touchscreen {
 196         struct drm_panel base;
 197         struct mipi_dsi_device *dsi;
 198         struct i2c_client *i2c;
 199 };
 200
 201 static const struct drm_display_mode rpi_touchscreen_modes[] = {
 202         {
 203                 /* Modeline comes from the Raspberry Pi firmware, with HFP=1
 204                  * plugged in and clock re-computed from that.
 205                  */
 206                 .clock = 25979400 / 1000,
 207                 .hdisplay = 800,
 208                 .hsync_start = 800 + 1,
 209                 .hsync_end = 800 + 1 + 2,
 210                 .htotal = 800 + 1 + 2 + 46,
 211                 .vdisplay = 480,
 212                 .vsync_start = 480 + 7,
 213                 .vsync_end = 480 + 7 + 2,
 214                 .vtotal = 480 + 7 + 2 + 21,
 215                 .vrefresh = 60,
 216         },
 217 };
 218
 219 static struct rpi_touchscreen *panel_to_ts(struct drm_panel *panel)
 220 {
 221         return container_of(panel, struct rpi_touchscreen, base);
 222 }
 223
 224 static int rpi_touchscreen_i2c_read(struct rpi_touchscreen *ts, u8 reg)
 225 {
 226         return i2c_smbus_read_byte_data(ts->i2c, reg);
 227 }
 228
 229 static void rpi_touchscreen_i2c_write(struct rpi_touchscreen *ts,
 230                                       u8 reg, u8 val)
 231 {
 232         int ret;
 233
 234         ret = i2c_smbus_write_byte_data(ts->i2c, reg, val);
 235         if (ret)
 236                 dev_err(&ts->i2c->dev, "I2C write failed: %d\n", ret);
 237 }
 238
 239 static int rpi_touchscreen_write(struct rpi_touchscreen *ts, u16 reg, u32 val)
 240 {
 241         u8 msg[] = {
 242                 reg,
 243                 reg >> 8,
 244                 val,
 245                 val >> 8,
 246                 val >> 16,
 247                 val >> 24,
 248         };
 249
 250         mipi_dsi_generic_write(ts->dsi, msg, sizeof(msg));
 251
 252         return 0;
 253 }
 254
 255 static int rpi_touchscreen_disable(struct drm_panel *panel)
 256 {
 257         struct rpi_touchscreen *ts = panel_to_ts(panel);
 258
 259         rpi_touchscreen_i2c_write(ts, REG_PWM, 0);
 260
 261         rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
 262         udelay(1);
 263
 264         return 0;
 265 }
 266
 267 static int rpi_touchscreen_noop(struct drm_panel *panel)
 268 {
 269         return 0;
 270 }
 271
 272 static int rpi_touchscreen_prepare(struct drm_panel *panel)
 273 {
 274         struct rpi_touchscreen *ts = panel_to_ts(panel);
 275         int i;
 276
 277         rpi_touchscreen_i2c_write(ts, REG_POWERON, 1);
 278         /* Wait for nPWRDWN to go low to indicate poweron is done. */
 279         for (i = 0; i < 100; i++) {
 280                 if (rpi_touchscreen_i2c_read(ts, REG_PORTB) & 1)
 281                         break;
 282         }
 283
 284         rpi_touchscreen_write(ts, DSI_LANEENABLE,
 285                               DSI_LANEENABLE_CLOCK |
 286                               DSI_LANEENABLE_D0);
 287         rpi_touchscreen_write(ts, PPI_D0S_CLRSIPOCOUNT, 0x05);
 288         rpi_touchscreen_write(ts, PPI_D1S_CLRSIPOCOUNT, 0x05);
 289         rpi_touchscreen_write(ts, PPI_D0S_ATMR, 0x00);
 290         rpi_touchscreen_write(ts, PPI_D1S_ATMR, 0x00);
 291         rpi_touchscreen_write(ts, PPI_LPTXTIMECNT, 0x03);
 292
 293         rpi_touchscreen_write(ts, SPICMR, 0x00);
 294         rpi_touchscreen_write(ts, LCDCTRL, 0x00100150);
 295         rpi_touchscreen_write(ts, SYSCTRL, 0x040f);
 296         msleep(100);
 297
 298         rpi_touchscreen_write(ts, PPI_STARTPPI, 0x01);
 299         rpi_touchscreen_write(ts, DSI_STARTDSI, 0x01);
 300         msleep(100);
 301
 302         return 0;
 303 }
 304
 305 static int rpi_touchscreen_enable(struct drm_panel *panel)
 306 {
 307         struct rpi_touchscreen *ts = panel_to_ts(panel);
 308
 309         /* Turn on the backlight. */
 310         rpi_touchscreen_i2c_write(ts, REG_PWM, 255);
 311
 312         /* Default to the same orientation as the closed source
 313          * firmware used for the panel.  Runtime rotation
 314          * configuration will be supported using VC4's plane
 315          * orientation bits.
 316          */
 317         rpi_touchscreen_i2c_write(ts, REG_PORTA, BIT(2));
 318
 319         return 0;
 320 }
 321
 322 static int rpi_touchscreen_get_modes(struct drm_panel *panel)
 323 {
 324         struct drm_connector *connector = panel->connector;
 325         struct drm_device *drm = panel->drm;
 326         unsigned int i, num = 0;
 327         static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
 328
 329         for (i = 0; i < ARRAY_SIZE(rpi_touchscreen_modes); i++) {
 330                 const struct drm_display_mode *m = &rpi_touchscreen_modes[i];
 331                 struct drm_display_mode *mode;
 332
 333                 mode = drm_mode_duplicate(drm, m);
 334                 if (!mode) {
 335                         dev_err(drm->dev, "failed to add mode %ux%u@%u\n",
 336                                 m->hdisplay, m->vdisplay, m->vrefresh);
 337                         continue;
 338                 }
 339
 340                 mode->type |= DRM_MODE_TYPE_DRIVER;
 341
 342                 if (i == 0)
 343                         mode->type |= DRM_MODE_TYPE_PREFERRED;
 344
 345                 drm_mode_set_name(mode);
 346
 347                 drm_mode_probed_add(connector, mode);
 348                 num++;
 349         }
 350
 351         connector->display_info.bpc = 8;
 352         connector->display_info.width_mm = 154;
 353         connector->display_info.height_mm = 86;
 354         drm_display_info_set_bus_formats(&connector->display_info,
 355                                          &bus_format, 1);
 356
 357         return num;
 358 }
 359
 360 static const struct drm_panel_funcs rpi_touchscreen_funcs = {
 361         .disable = rpi_touchscreen_disable,
 362         .unprepare = rpi_touchscreen_noop,
 363         .prepare = rpi_touchscreen_prepare,
 364         .enable = rpi_touchscreen_enable,
 365         .get_modes = rpi_touchscreen_get_modes,
 366 };
 367
 368 static int rpi_touchscreen_probe(struct i2c_client *i2c,
 369                                  const struct i2c_device_id *id)
 370 {
 371         struct device *dev = &i2c->dev;
 372         struct rpi_touchscreen *ts;
 373         struct device_node *endpoint, *dsi_host_node;
 374         struct mipi_dsi_host *host;
 375         int ret, ver;
 376         struct mipi_dsi_device_info info = {
 377                 .type = RPI_DSI_DRIVER_NAME,
 378                 .channel = 0,
 379                 .node = NULL,
 380         };
 381
 382         ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
 383         if (!ts)
 384                 return -ENOMEM;
 385
 386         i2c_set_clientdata(i2c, ts);
 387
 388         ts->i2c = i2c;
 389
 390         ver = rpi_touchscreen_i2c_read(ts, REG_ID);
 391         if (ver < 0) {
 392                 dev_err(dev, "Atmel I2C read failed: %d\n", ver);
 393                 return -ENODEV;
 394         }
 395
 396         switch (ver) {
 397         case 0xde: /* ver 1 */
 398         case 0xc3: /* ver 2 */
 399                 break;
 400         default:
 401                 dev_err(dev, "Unknown Atmel firmware revision: 0x%02x\n", ver);
 402                 return -ENODEV;
 403         }
 404
 405         /* Turn off at boot, so we can cleanly sequence powering on. */
 406         rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
 407
 408         /* Look up the DSI host.  It needs to probe before we do. */
 409         endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
 410         if (!endpoint)
 411                 return -ENODEV;
 412
 413         dsi_host_node = of_graph_get_remote_port_parent(endpoint);
 414         if (!dsi_host_node)
 415                 goto error;
 416
 417         host = of_find_mipi_dsi_host_by_node(dsi_host_node);
 418         of_node_put(dsi_host_node);
 419         if (!host) {
 420                 of_node_put(endpoint);
 421                 return -EPROBE_DEFER;
 422         }
 423
 424         info.node = of_graph_get_remote_port(endpoint);
 425         if (!info.node)
 426                 goto error;
 427
 428         of_node_put(endpoint);
 429
 430         ts->dsi = mipi_dsi_device_register_full(host, &info);
 431         if (IS_ERR(ts->dsi)) {
 432                 dev_err(dev, "DSI device registration failed: %ld\n",
 433                         PTR_ERR(ts->dsi));
 434                 return PTR_ERR(ts->dsi);
 435         }
 436
 437         drm_panel_init(&ts->base);
 438         ts->base.dev = dev;
 439         ts->base.funcs = &rpi_touchscreen_funcs;
 440
 441         /* This appears last, as it's what will unblock the DSI host
 442          * driver's component bind function.
 443          */
 444         ret = drm_panel_add(&ts->base);
 445         if (ret)
 446                 return ret;
 447
 448         return 0;
 449
 450 error:
 451         of_node_put(endpoint);
 452         return -ENODEV;
 453 }
 454
 455 static int rpi_touchscreen_remove(struct i2c_client *i2c)
 456 {
 457         struct rpi_touchscreen *ts = i2c_get_clientdata(i2c);
 458
 459         mipi_dsi_detach(ts->dsi);
 460
 461         drm_panel_remove(&ts->base);
 462
 463         mipi_dsi_device_unregister(ts->dsi);
 464
 465         return 0;
 466 }
 467
 468 static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi)
 469 {
 470         int ret;
 471
 472         dsi->mode_flags = (MIPI_DSI_MODE_VIDEO |
 473                            MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
 474                            MIPI_DSI_MODE_LPM);
 475         dsi->format = MIPI_DSI_FMT_RGB888;
 476         dsi->lanes = 1;
 477
 478         ret = mipi_dsi_attach(dsi);
 479
 480         if (ret)
 481                 dev_err(&dsi->dev, "failed to attach dsi to host: %d\n", ret);
 482
 483         return ret;
 484 }
 485
 486 static struct mipi_dsi_driver rpi_touchscreen_dsi_driver = {
 487         .driver.name = RPI_DSI_DRIVER_NAME,
 488         .probe = rpi_touchscreen_dsi_probe,
 489 };
 490
 491 static const struct of_device_id rpi_touchscreen_of_ids[] = {
 492         { .compatible = "raspberrypi,7inch-touchscreen-panel" },
 493         { } /* sentinel */
 494 };
 495 MODULE_DEVICE_TABLE(of, rpi_touchscreen_of_ids);
 496
 497 static struct i2c_driver rpi_touchscreen_driver = {
 498         .driver = {
 499                 .name = "rpi_touchscreen",
 500                 .of_match_table = rpi_touchscreen_of_ids,
 501         },
 502         .probe = rpi_touchscreen_probe,
 503         .remove = rpi_touchscreen_remove,
 504 };
 505
 506 static int __init rpi_touchscreen_init(void)
 507 {
 508         mipi_dsi_driver_register(&rpi_touchscreen_dsi_driver);
 509         return i2c_add_driver(&rpi_touchscreen_driver);
 510 }
 511 module_init(rpi_touchscreen_init);
 512
 513 static void __exit rpi_touchscreen_exit(void)
 514 {
 515         i2c_del_driver(&rpi_touchscreen_driver);
 516         mipi_dsi_driver_unregister(&rpi_touchscreen_dsi_driver);
 517 }
 518 module_exit(rpi_touchscreen_exit);
 519
 520 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
 521 MODULE_DESCRIPTION("Raspberry Pi 7-inch touchscreen driver");
 522 MODULE_LICENSE("GPL v2");