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