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->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"); 515