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 u8 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->dsi->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 #if 0
 242         /* The firmware uses LP DSI transactions like this to bring up
 243          * the hardware, which should be faster than using I2C to then
 244          * pass to the Toshiba.  However, I was unable to get it to
 245          * work.
 246          */
 247         u8 msg[] = {
 248                 reg,
 249                 reg >> 8,
 250                 val,
 251                 val >> 8,
 252                 val >> 16,
 253                 val >> 24,
 254         };
 255
 256         mipi_dsi_dcs_write_buffer(ts->dsi, msg, sizeof(msg));
 257 #else
 258         rpi_touchscreen_i2c_write(ts, REG_WR_ADDRH, reg >> 8);
 259         rpi_touchscreen_i2c_write(ts, REG_WR_ADDRL, reg);
 260         rpi_touchscreen_i2c_write(ts, REG_WRITEH, val >> 8);
 261         rpi_touchscreen_i2c_write(ts, REG_WRITEL, val);
 262 #endif
 263
 264         return 0;
 265 }
 266
 267 static int rpi_touchscreen_disable(struct drm_panel *panel)
 268 {
 269         struct rpi_touchscreen *ts = panel_to_ts(panel);
 270
 271         rpi_touchscreen_i2c_write(ts, REG_PWM, 0);
 272
 273         rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
 274         udelay(1);
 275
 276         return 0;
 277 }
 278
 279 static int rpi_touchscreen_noop(struct drm_panel *panel)
 280 {
 281         return 0;
 282 }
 283
 284 static int rpi_touchscreen_enable(struct drm_panel *panel)
 285 {
 286         struct rpi_touchscreen *ts = panel_to_ts(panel);
 287         int i;
 288
 289         rpi_touchscreen_i2c_write(ts, REG_POWERON, 1);
 290         /* Wait for nPWRDWN to go low to indicate poweron is done. */
 291         for (i = 0; i < 100; i++) {
 292                 if (rpi_touchscreen_i2c_read(ts, REG_PORTB) & 1)
 293                         break;
 294         }
 295
 296         rpi_touchscreen_write(ts, DSI_LANEENABLE,
 297                               DSI_LANEENABLE_CLOCK |
 298                               DSI_LANEENABLE_D0);
 299         rpi_touchscreen_write(ts, PPI_D0S_CLRSIPOCOUNT, 0x05);
 300         rpi_touchscreen_write(ts, PPI_D1S_CLRSIPOCOUNT, 0x05);
 301         rpi_touchscreen_write(ts, PPI_D0S_ATMR, 0x00);
 302         rpi_touchscreen_write(ts, PPI_D1S_ATMR, 0x00);
 303         rpi_touchscreen_write(ts, PPI_LPTXTIMECNT, 0x03);
 304
 305         rpi_touchscreen_write(ts, SPICMR, 0x00);
 306         rpi_touchscreen_write(ts, LCDCTRL, 0x00100150);
 307         rpi_touchscreen_write(ts, SYSCTRL, 0x040f);
 308         msleep(100);
 309
 310         rpi_touchscreen_write(ts, PPI_STARTPPI, 0x01);
 311         rpi_touchscreen_write(ts, DSI_STARTDSI, 0x01);
 312         msleep(100);
 313
 314         /* Turn on the backlight. */
 315         rpi_touchscreen_i2c_write(ts, REG_PWM, 255);
 316
 317         /* Default to the same orientation as the closed source
 318          * firmware used for the panel.  Runtime rotation
 319          * configuration will be supported using VC4's plane
 320          * orientation bits.
 321          */
 322         rpi_touchscreen_i2c_write(ts, REG_PORTA, BIT(2));
 323
 324         return 0;
 325 }
 326
 327 static int rpi_touchscreen_get_modes(struct drm_panel *panel)
 328 {
 329         struct drm_connector *connector = panel->connector;
 330         struct drm_device *drm = panel->drm;
 331         unsigned int i, num = 0;
 332         static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
 333
 334         for (i = 0; i < ARRAY_SIZE(rpi_touchscreen_modes); i++) {
 335                 const struct drm_display_mode *m = &rpi_touchscreen_modes[i];
 336                 struct drm_display_mode *mode;
 337
 338                 mode = drm_mode_duplicate(drm, m);
 339                 if (!mode) {
 340                         dev_err(drm->dev, "failed to add mode %ux%u@%u\n",
 341                                 m->hdisplay, m->vdisplay, m->vrefresh);
 342                         continue;
 343                 }
 344
 345                 mode->type |= DRM_MODE_TYPE_DRIVER;
 346
 347                 if (i == 0)
 348                         mode->type |= DRM_MODE_TYPE_PREFERRED;
 349
 350                 drm_mode_set_name(mode);
 351
 352                 drm_mode_probed_add(connector, mode);
 353                 num++;
 354         }
 355
 356         connector->display_info.bpc = 8;
 357         connector->display_info.width_mm = 154;
 358         connector->display_info.height_mm = 86;
 359         drm_display_info_set_bus_formats(&connector->display_info,
 360                                          &bus_format, 1);
 361
 362         return num;
 363 }
 364
 365 static const struct drm_panel_funcs rpi_touchscreen_funcs = {
 366         .disable = rpi_touchscreen_disable,
 367         .unprepare = rpi_touchscreen_noop,
 368         .prepare = rpi_touchscreen_noop,
 369         .enable = rpi_touchscreen_enable,
 370         .get_modes = rpi_touchscreen_get_modes,
 371 };
 372
 373 static int rpi_touchscreen_probe(struct i2c_client *i2c,
 374                                  const struct i2c_device_id *id)
 375 {
 376         struct device *dev = &i2c->dev;
 377         struct rpi_touchscreen *ts;
 378         struct device_node *endpoint, *dsi_host_node;
 379         struct mipi_dsi_host *host;
 380         int ret, ver;
 381         struct mipi_dsi_device_info info = {
 382                 .type = RPI_DSI_DRIVER_NAME,
 383                 .channel = 0,
 384                 .node = NULL,
 385         };
 386
 387         ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
 388         if (!ts)
 389                 return -ENOMEM;
 390
 391         i2c_set_clientdata(i2c, ts);
 392
 393         ts->i2c = i2c;
 394
 395         ver = rpi_touchscreen_i2c_read(ts, REG_ID);
 396         if (ver < 0) {
 397                 dev_err(dev, "Atmel I2C read failed: %d\n", ver);
 398                 return -ENODEV;
 399         }
 400
 401         switch (ver) {
 402         case 0xde: /* ver 1 */
 403         case 0xc3: /* ver 2 */
 404                 break;
 405         default:
 406                 dev_err(dev, "Unknown Atmel firmware revision: 0x%02x\n", ver);
 407                 return -ENODEV;
 408         }
 409
 410         /* Turn off at boot, so we can cleanly sequence powering on. */
 411         rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
 412
 413         /* Look up the DSI host.  It needs to probe before we do. */
 414         endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
 415         dsi_host_node = of_graph_get_remote_port_parent(endpoint);
 416         host = of_find_mipi_dsi_host_by_node(dsi_host_node);
 417         of_node_put(dsi_host_node);
 418         if (!host) {
 419                 of_node_put(endpoint);
 420                 return -EPROBE_DEFER;
 421         }
 422
 423         info.node = of_graph_get_remote_port(endpoint);
 424         of_node_put(endpoint);
 425
 426         ts->dsi = mipi_dsi_device_register_full(host, &info);
 427         if (IS_ERR(ts->dsi)) {
 428                 dev_err(dev, "DSI device registration failed: %ld\n",
 429                         PTR_ERR(ts->dsi));
 430                 return PTR_ERR(ts->dsi);
 431         }
 432
 433         ts->base.dev = dev;
 434         ts->base.funcs = &rpi_touchscreen_funcs;
 435
 436         /* This appears last, as it's what will unblock the DSI host
 437          * driver's component bind function.
 438          */
 439         ret = drm_panel_add(&ts->base);
 440         if (ret)
 441                 return ret;
 442
 443         return 0;
 444 }
 445
 446 static int 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         kfree(ts->dsi);
 456
 457         return 0;
 458 }
 459
 460 static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi)
 461 {
 462         int ret;
 463
 464         dsi->mode_flags = (MIPI_DSI_MODE_VIDEO |
 465                            MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
 466                            MIPI_DSI_MODE_LPM);
 467         dsi->format = MIPI_DSI_FMT_RGB888;
 468         dsi->lanes = 1;
 469
 470         ret = mipi_dsi_attach(dsi);
 471
 472         if (ret)
 473                 dev_err(&dsi->dev, "failed to attach dsi to host: %d\n", ret);
 474
 475         return ret;
 476 }
 477
 478 static struct mipi_dsi_driver rpi_touchscreen_dsi_driver = {
 479         .driver.name = RPI_DSI_DRIVER_NAME,
 480         .probe = rpi_touchscreen_dsi_probe,
 481 };
 482
 483 static const struct of_device_id rpi_touchscreen_of_ids[] = {
 484         { .compatible = "raspberrypi,7inch-touchscreen-panel" },
 485         { } /* sentinel */
 486 };
 487 MODULE_DEVICE_TABLE(of, rpi_touchscreen_of_ids);
 488
 489 static struct i2c_driver rpi_touchscreen_driver = {
 490         .driver = {
 491                 .name = "rpi_touchscreen",
 492                 .of_match_table = rpi_touchscreen_of_ids,
 493         },
 494         .probe = rpi_touchscreen_probe,
 495         .remove = rpi_touchscreen_remove,
 496 };
 497
 498 static int __init rpi_touchscreen_init(void)
 499 {
 500         mipi_dsi_driver_register(&rpi_touchscreen_dsi_driver);
 501         return i2c_add_driver(&rpi_touchscreen_driver);
 502 }
 503 module_init(rpi_touchscreen_init);
 504
 505 static void __exit rpi_touchscreen_exit(void)
 506 {
 507         i2c_del_driver(&rpi_touchscreen_driver);
 508         mipi_dsi_driver_unregister(&rpi_touchscreen_dsi_driver);
 509 }
 510 module_exit(rpi_touchscreen_exit);
 511
 512 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
 513 MODULE_DESCRIPTION("Raspberry Pi 7-inch touchscreen driver");
 514 MODULE_LICENSE("GPL v2");