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