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. */
64 enum 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
194 struct rpi_touchscreen {
195 struct drm_panel base;
196 struct mipi_dsi_device *dsi;
197 struct i2c_client *i2c;
198 };
199
200 static 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
panel_to_ts(struct drm_panel * panel)218 static struct rpi_touchscreen *panel_to_ts(struct drm_panel *panel)
219 {
220 return container_of(panel, struct rpi_touchscreen, base);
221 }
222
rpi_touchscreen_i2c_read(struct rpi_touchscreen * ts,u8 reg)223 static int rpi_touchscreen_i2c_read(struct rpi_touchscreen *ts, u8 reg)
224 {
225 return i2c_smbus_read_byte_data(ts->i2c, reg);
226 }
227
rpi_touchscreen_i2c_write(struct rpi_touchscreen * ts,u8 reg,u8 val)228 static 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
rpi_touchscreen_write(struct rpi_touchscreen * ts,u16 reg,u32 val)238 static 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
rpi_touchscreen_disable(struct drm_panel * panel)254 static 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
rpi_touchscreen_noop(struct drm_panel * panel)266 static int rpi_touchscreen_noop(struct drm_panel *panel)
267 {
268 return 0;
269 }
270
rpi_touchscreen_enable(struct drm_panel * panel)271 static 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
rpi_touchscreen_get_modes(struct drm_panel * panel)314 static 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
352 static 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
rpi_touchscreen_probe(struct i2c_client * i2c,const struct i2c_device_id * id)360 static 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 if (!endpoint)
403 return -ENODEV;
404
405 dsi_host_node = of_graph_get_remote_port_parent(endpoint);
406 if (!dsi_host_node)
407 goto error;
408
409 host = of_find_mipi_dsi_host_by_node(dsi_host_node);
410 of_node_put(dsi_host_node);
411 if (!host) {
412 of_node_put(endpoint);
413 return -EPROBE_DEFER;
414 }
415
416 info.node = of_graph_get_remote_port(endpoint);
417 if (!info.node)
418 goto error;
419
420 of_node_put(endpoint);
421
422 ts->dsi = mipi_dsi_device_register_full(host, &info);
423 if (IS_ERR(ts->dsi)) {
424 dev_err(dev, "DSI device registration failed: %ld\n",
425 PTR_ERR(ts->dsi));
426 return PTR_ERR(ts->dsi);
427 }
428
429 ts->base.dev = dev;
430 ts->base.funcs = &rpi_touchscreen_funcs;
431
432 /* This appears last, as it's what will unblock the DSI host
433 * driver's component bind function.
434 */
435 ret = drm_panel_add(&ts->base);
436 if (ret)
437 return ret;
438
439 return 0;
440
441 error:
442 of_node_put(endpoint);
443 return -ENODEV;
444 }
445
rpi_touchscreen_remove(struct i2c_client * i2c)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
rpi_touchscreen_dsi_probe(struct mipi_dsi_device * dsi)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
rpi_touchscreen_init(void)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
rpi_touchscreen_exit(void)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
