1 /*
2  * LCD driver for MIPI DBI-C / DCS compatible LCDs
3  *
4  * Copyright (C) 2006 Nokia Corporation
5  * Author: Imre Deak <imre.deak@nokia.com>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License as published by the
9  * Free Software Foundation; either version 2 of the License, or (at your
10  * option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful, but
13  * WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License along
18  * with this program; if not, write to the Free Software Foundation, Inc.,
19  * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
20  */
21 #include <linux/device.h>
22 #include <linux/delay.h>
23 #include <linux/slab.h>
24 #include <linux/workqueue.h>
25 #include <linux/spi/spi.h>
26 #include <linux/module.h>
27 
28 #include <linux/platform_data/lcd-mipid.h>
29 
30 #include "omapfb.h"
31 
32 #define MIPID_MODULE_NAME		"lcd_mipid"
33 
34 #define MIPID_CMD_READ_DISP_ID		0x04
35 #define MIPID_CMD_READ_RED		0x06
36 #define MIPID_CMD_READ_GREEN		0x07
37 #define MIPID_CMD_READ_BLUE		0x08
38 #define MIPID_CMD_READ_DISP_STATUS	0x09
39 #define MIPID_CMD_RDDSDR		0x0F
40 #define MIPID_CMD_SLEEP_IN		0x10
41 #define MIPID_CMD_SLEEP_OUT		0x11
42 #define MIPID_CMD_DISP_OFF		0x28
43 #define MIPID_CMD_DISP_ON		0x29
44 
45 #define MIPID_ESD_CHECK_PERIOD		msecs_to_jiffies(5000)
46 
47 #define to_mipid_device(p)		container_of(p, struct mipid_device, \
48 						panel)
49 struct mipid_device {
50 	int		enabled;
51 	int		revision;
52 	unsigned int	saved_bklight_level;
53 	unsigned long	hw_guard_end;		/* next value of jiffies
54 						   when we can issue the
55 						   next sleep in/out command */
56 	unsigned long	hw_guard_wait;		/* max guard time in jiffies */
57 
58 	struct omapfb_device	*fbdev;
59 	struct spi_device	*spi;
60 	struct mutex		mutex;
61 	struct lcd_panel	panel;
62 
63 	struct workqueue_struct	*esd_wq;
64 	struct delayed_work	esd_work;
65 	void			(*esd_check)(struct mipid_device *m);
66 };
67 
68 static void mipid_transfer(struct mipid_device *md, int cmd, const u8 *wbuf,
69 			   int wlen, u8 *rbuf, int rlen)
70 {
71 	struct spi_message	m;
72 	struct spi_transfer	*x, xfer[4];
73 	u16			w;
74 	int			r;
75 
76 	BUG_ON(md->spi == NULL);
77 
78 	spi_message_init(&m);
79 
80 	memset(xfer, 0, sizeof(xfer));
81 	x = &xfer[0];
82 
83 	cmd &=  0xff;
84 	x->tx_buf		= &cmd;
85 	x->bits_per_word	= 9;
86 	x->len			= 2;
87 	spi_message_add_tail(x, &m);
88 
89 	if (wlen) {
90 		x++;
91 		x->tx_buf		= wbuf;
92 		x->len			= wlen;
93 		x->bits_per_word	= 9;
94 		spi_message_add_tail(x, &m);
95 	}
96 
97 	if (rlen) {
98 		x++;
99 		x->rx_buf	= &w;
100 		x->len		= 1;
101 		spi_message_add_tail(x, &m);
102 
103 		if (rlen > 1) {
104 			/* Arrange for the extra clock before the first
105 			 * data bit.
106 			 */
107 			x->bits_per_word = 9;
108 			x->len		 = 2;
109 
110 			x++;
111 			x->rx_buf	 = &rbuf[1];
112 			x->len		 = rlen - 1;
113 			spi_message_add_tail(x, &m);
114 		}
115 	}
116 
117 	r = spi_sync(md->spi, &m);
118 	if (r < 0)
119 		dev_dbg(&md->spi->dev, "spi_sync %d\n", r);
120 
121 	if (rlen)
122 		rbuf[0] = w & 0xff;
123 }
124 
125 static inline void mipid_cmd(struct mipid_device *md, int cmd)
126 {
127 	mipid_transfer(md, cmd, NULL, 0, NULL, 0);
128 }
129 
130 static inline void mipid_write(struct mipid_device *md,
131 			       int reg, const u8 *buf, int len)
132 {
133 	mipid_transfer(md, reg, buf, len, NULL, 0);
134 }
135 
136 static inline void mipid_read(struct mipid_device *md,
137 			      int reg, u8 *buf, int len)
138 {
139 	mipid_transfer(md, reg, NULL, 0, buf, len);
140 }
141 
142 static void set_data_lines(struct mipid_device *md, int data_lines)
143 {
144 	u16 par;
145 
146 	switch (data_lines) {
147 	case 16:
148 		par = 0x150;
149 		break;
150 	case 18:
151 		par = 0x160;
152 		break;
153 	case 24:
154 		par = 0x170;
155 		break;
156 	}
157 	mipid_write(md, 0x3a, (u8 *)&par, 2);
158 }
159 
160 static void send_init_string(struct mipid_device *md)
161 {
162 	u16 initpar[] = { 0x0102, 0x0100, 0x0100 };
163 
164 	mipid_write(md, 0xc2, (u8 *)initpar, sizeof(initpar));
165 	set_data_lines(md, md->panel.data_lines);
166 }
167 
168 static void hw_guard_start(struct mipid_device *md, int guard_msec)
169 {
170 	md->hw_guard_wait = msecs_to_jiffies(guard_msec);
171 	md->hw_guard_end = jiffies + md->hw_guard_wait;
172 }
173 
174 static void hw_guard_wait(struct mipid_device *md)
175 {
176 	unsigned long wait = md->hw_guard_end - jiffies;
177 
178 	if ((long)wait > 0 && wait <= md->hw_guard_wait) {
179 		set_current_state(TASK_UNINTERRUPTIBLE);
180 		schedule_timeout(wait);
181 	}
182 }
183 
184 static void set_sleep_mode(struct mipid_device *md, int on)
185 {
186 	int cmd, sleep_time = 50;
187 
188 	if (on)
189 		cmd = MIPID_CMD_SLEEP_IN;
190 	else
191 		cmd = MIPID_CMD_SLEEP_OUT;
192 	hw_guard_wait(md);
193 	mipid_cmd(md, cmd);
194 	hw_guard_start(md, 120);
195 	/*
196 	 * When we enable the panel, it seems we _have_ to sleep
197 	 * 120 ms before sending the init string. When disabling the
198 	 * panel we'll sleep for the duration of 2 frames, so that the
199 	 * controller can still provide the PCLK,HS,VS signals.
200 	 */
201 	if (!on)
202 		sleep_time = 120;
203 	msleep(sleep_time);
204 }
205 
206 static void set_display_state(struct mipid_device *md, int enabled)
207 {
208 	int cmd = enabled ? MIPID_CMD_DISP_ON : MIPID_CMD_DISP_OFF;
209 
210 	mipid_cmd(md, cmd);
211 }
212 
213 static int mipid_set_bklight_level(struct lcd_panel *panel, unsigned int level)
214 {
215 	struct mipid_device *md = to_mipid_device(panel);
216 	struct mipid_platform_data *pd = md->spi->dev.platform_data;
217 
218 	if (pd->get_bklight_max == NULL || pd->set_bklight_level == NULL)
219 		return -ENODEV;
220 	if (level > pd->get_bklight_max(pd))
221 		return -EINVAL;
222 	if (!md->enabled) {
223 		md->saved_bklight_level = level;
224 		return 0;
225 	}
226 	pd->set_bklight_level(pd, level);
227 
228 	return 0;
229 }
230 
231 static unsigned int mipid_get_bklight_level(struct lcd_panel *panel)
232 {
233 	struct mipid_device *md = to_mipid_device(panel);
234 	struct mipid_platform_data *pd = md->spi->dev.platform_data;
235 
236 	if (pd->get_bklight_level == NULL)
237 		return -ENODEV;
238 	return pd->get_bklight_level(pd);
239 }
240 
241 static unsigned int mipid_get_bklight_max(struct lcd_panel *panel)
242 {
243 	struct mipid_device *md = to_mipid_device(panel);
244 	struct mipid_platform_data *pd = md->spi->dev.platform_data;
245 
246 	if (pd->get_bklight_max == NULL)
247 		return -ENODEV;
248 
249 	return pd->get_bklight_max(pd);
250 }
251 
252 static unsigned long mipid_get_caps(struct lcd_panel *panel)
253 {
254 	return OMAPFB_CAPS_SET_BACKLIGHT;
255 }
256 
257 static u16 read_first_pixel(struct mipid_device *md)
258 {
259 	u16 pixel;
260 	u8 red, green, blue;
261 
262 	mutex_lock(&md->mutex);
263 	mipid_read(md, MIPID_CMD_READ_RED, &red, 1);
264 	mipid_read(md, MIPID_CMD_READ_GREEN, &green, 1);
265 	mipid_read(md, MIPID_CMD_READ_BLUE, &blue, 1);
266 	mutex_unlock(&md->mutex);
267 
268 	switch (md->panel.data_lines) {
269 	case 16:
270 		pixel = ((red >> 1) << 11) | (green << 5) | (blue >> 1);
271 		break;
272 	case 24:
273 		/* 24 bit -> 16 bit */
274 		pixel = ((red >> 3) << 11) | ((green >> 2) << 5) |
275 			(blue >> 3);
276 		break;
277 	default:
278 		pixel = 0;
279 		BUG();
280 	}
281 
282 	return pixel;
283 }
284 
285 static int mipid_run_test(struct lcd_panel *panel, int test_num)
286 {
287 	struct mipid_device *md = to_mipid_device(panel);
288 	static const u16 test_values[4] = {
289 		0x0000, 0xffff, 0xaaaa, 0x5555,
290 	};
291 	int i;
292 
293 	if (test_num != MIPID_TEST_RGB_LINES)
294 		return MIPID_TEST_INVALID;
295 
296 	for (i = 0; i < ARRAY_SIZE(test_values); i++) {
297 		int delay;
298 		unsigned long tmo;
299 
300 		omapfb_write_first_pixel(md->fbdev, test_values[i]);
301 		tmo = jiffies + msecs_to_jiffies(100);
302 		delay = 25;
303 		while (1) {
304 			u16 pixel;
305 
306 			msleep(delay);
307 			pixel = read_first_pixel(md);
308 			if (pixel == test_values[i])
309 				break;
310 			if (time_after(jiffies, tmo)) {
311 				dev_err(&md->spi->dev,
312 					"MIPI LCD RGB I/F test failed: "
313 					"expecting %04x, got %04x\n",
314 					test_values[i], pixel);
315 				return MIPID_TEST_FAILED;
316 			}
317 			delay = 10;
318 		}
319 	}
320 
321 	return 0;
322 }
323 
324 static void ls041y3_esd_recover(struct mipid_device *md)
325 {
326 	dev_err(&md->spi->dev, "performing LCD ESD recovery\n");
327 	set_sleep_mode(md, 1);
328 	set_sleep_mode(md, 0);
329 }
330 
331 static void ls041y3_esd_check_mode1(struct mipid_device *md)
332 {
333 	u8 state1, state2;
334 
335 	mipid_read(md, MIPID_CMD_RDDSDR, &state1, 1);
336 	set_sleep_mode(md, 0);
337 	mipid_read(md, MIPID_CMD_RDDSDR, &state2, 1);
338 	dev_dbg(&md->spi->dev, "ESD mode 1 state1 %02x state2 %02x\n",
339 		state1, state2);
340 	/* Each sleep out command will trigger a self diagnostic and flip
341 	* Bit6 if the test passes.
342 	*/
343 	if (!((state1 ^ state2) & (1 << 6)))
344 		ls041y3_esd_recover(md);
345 }
346 
347 static void ls041y3_esd_check_mode2(struct mipid_device *md)
348 {
349 	int i;
350 	u8 rbuf[2];
351 	static const struct {
352 		int	cmd;
353 		int	wlen;
354 		u16	wbuf[3];
355 	} *rd, rd_ctrl[7] = {
356 		{ 0xb0, 4, { 0x0101, 0x01fe, } },
357 		{ 0xb1, 4, { 0x01de, 0x0121, } },
358 		{ 0xc2, 4, { 0x0100, 0x0100, } },
359 		{ 0xbd, 2, { 0x0100, } },
360 		{ 0xc2, 4, { 0x01fc, 0x0103, } },
361 		{ 0xb4, 0, },
362 		{ 0x00, 0, },
363 	};
364 
365 	rd = rd_ctrl;
366 	for (i = 0; i < 3; i++, rd++)
367 		mipid_write(md, rd->cmd, (u8 *)rd->wbuf, rd->wlen);
368 
369 	udelay(10);
370 	mipid_read(md, rd->cmd, rbuf, 2);
371 	rd++;
372 
373 	for (i = 0; i < 3; i++, rd++) {
374 		udelay(10);
375 		mipid_write(md, rd->cmd, (u8 *)rd->wbuf, rd->wlen);
376 	}
377 
378 	dev_dbg(&md->spi->dev, "ESD mode 2 state %02x\n", rbuf[1]);
379 	if (rbuf[1] == 0x00)
380 		ls041y3_esd_recover(md);
381 }
382 
383 static void ls041y3_esd_check(struct mipid_device *md)
384 {
385 	ls041y3_esd_check_mode1(md);
386 	if (md->revision >= 0x88)
387 		ls041y3_esd_check_mode2(md);
388 }
389 
390 static void mipid_esd_start_check(struct mipid_device *md)
391 {
392 	if (md->esd_check != NULL)
393 		queue_delayed_work(md->esd_wq, &md->esd_work,
394 				   MIPID_ESD_CHECK_PERIOD);
395 }
396 
397 static void mipid_esd_stop_check(struct mipid_device *md)
398 {
399 	if (md->esd_check != NULL)
400 		cancel_delayed_work_sync(&md->esd_work);
401 }
402 
403 static void mipid_esd_work(struct work_struct *work)
404 {
405 	struct mipid_device *md = container_of(work, struct mipid_device,
406 					       esd_work.work);
407 
408 	mutex_lock(&md->mutex);
409 	md->esd_check(md);
410 	mutex_unlock(&md->mutex);
411 	mipid_esd_start_check(md);
412 }
413 
414 static int mipid_enable(struct lcd_panel *panel)
415 {
416 	struct mipid_device *md = to_mipid_device(panel);
417 
418 	mutex_lock(&md->mutex);
419 
420 	if (md->enabled) {
421 		mutex_unlock(&md->mutex);
422 		return 0;
423 	}
424 	set_sleep_mode(md, 0);
425 	md->enabled = 1;
426 	send_init_string(md);
427 	set_display_state(md, 1);
428 	mipid_set_bklight_level(panel, md->saved_bklight_level);
429 	mipid_esd_start_check(md);
430 
431 	mutex_unlock(&md->mutex);
432 	return 0;
433 }
434 
435 static void mipid_disable(struct lcd_panel *panel)
436 {
437 	struct mipid_device *md = to_mipid_device(panel);
438 
439 	/*
440 	 * A final ESD work might be called before returning,
441 	 * so do this without holding the lock.
442 	 */
443 	mipid_esd_stop_check(md);
444 	mutex_lock(&md->mutex);
445 
446 	if (!md->enabled) {
447 		mutex_unlock(&md->mutex);
448 		return;
449 	}
450 	md->saved_bklight_level = mipid_get_bklight_level(panel);
451 	mipid_set_bklight_level(panel, 0);
452 	set_display_state(md, 0);
453 	set_sleep_mode(md, 1);
454 	md->enabled = 0;
455 
456 	mutex_unlock(&md->mutex);
457 }
458 
459 static int panel_enabled(struct mipid_device *md)
460 {
461 	u32 disp_status;
462 	int enabled;
463 
464 	mipid_read(md, MIPID_CMD_READ_DISP_STATUS, (u8 *)&disp_status, 4);
465 	disp_status = __be32_to_cpu(disp_status);
466 	enabled = (disp_status & (1 << 17)) && (disp_status & (1 << 10));
467 	dev_dbg(&md->spi->dev,
468 		"LCD panel %senabled by bootloader (status 0x%04x)\n",
469 		enabled ? "" : "not ", disp_status);
470 	return enabled;
471 }
472 
473 static int mipid_init(struct lcd_panel *panel,
474 			    struct omapfb_device *fbdev)
475 {
476 	struct mipid_device *md = to_mipid_device(panel);
477 
478 	md->fbdev = fbdev;
479 	md->esd_wq = create_singlethread_workqueue("mipid_esd");
480 	if (md->esd_wq == NULL) {
481 		dev_err(&md->spi->dev, "can't create ESD workqueue\n");
482 		return -ENOMEM;
483 	}
484 	INIT_DELAYED_WORK(&md->esd_work, mipid_esd_work);
485 	mutex_init(&md->mutex);
486 
487 	md->enabled = panel_enabled(md);
488 
489 	if (md->enabled)
490 		mipid_esd_start_check(md);
491 	else
492 		md->saved_bklight_level = mipid_get_bklight_level(panel);
493 
494 	return 0;
495 }
496 
497 static void mipid_cleanup(struct lcd_panel *panel)
498 {
499 	struct mipid_device *md = to_mipid_device(panel);
500 
501 	if (md->enabled)
502 		mipid_esd_stop_check(md);
503 	destroy_workqueue(md->esd_wq);
504 }
505 
506 static struct lcd_panel mipid_panel = {
507 	.config		= OMAP_LCDC_PANEL_TFT,
508 
509 	.bpp		= 16,
510 	.x_res		= 800,
511 	.y_res		= 480,
512 	.pixel_clock	= 21940,
513 	.hsw		= 50,
514 	.hfp		= 20,
515 	.hbp		= 15,
516 	.vsw		= 2,
517 	.vfp		= 1,
518 	.vbp		= 3,
519 
520 	.init			= mipid_init,
521 	.cleanup		= mipid_cleanup,
522 	.enable			= mipid_enable,
523 	.disable		= mipid_disable,
524 	.get_caps		= mipid_get_caps,
525 	.set_bklight_level	= mipid_set_bklight_level,
526 	.get_bklight_level	= mipid_get_bklight_level,
527 	.get_bklight_max	= mipid_get_bklight_max,
528 	.run_test		= mipid_run_test,
529 };
530 
531 static int mipid_detect(struct mipid_device *md)
532 {
533 	struct mipid_platform_data *pdata;
534 	u8 display_id[3];
535 
536 	pdata = md->spi->dev.platform_data;
537 	if (pdata == NULL) {
538 		dev_err(&md->spi->dev, "missing platform data\n");
539 		return -ENOENT;
540 	}
541 
542 	mipid_read(md, MIPID_CMD_READ_DISP_ID, display_id, 3);
543 	dev_dbg(&md->spi->dev, "MIPI display ID: %02x%02x%02x\n",
544 		display_id[0], display_id[1], display_id[2]);
545 
546 	switch (display_id[0]) {
547 	case 0x45:
548 		md->panel.name = "lph8923";
549 		break;
550 	case 0x83:
551 		md->panel.name = "ls041y3";
552 		md->esd_check = ls041y3_esd_check;
553 		break;
554 	default:
555 		md->panel.name = "unknown";
556 		dev_err(&md->spi->dev, "invalid display ID\n");
557 		return -ENODEV;
558 	}
559 
560 	md->revision = display_id[1];
561 	md->panel.data_lines = pdata->data_lines;
562 	pr_info("omapfb: %s rev %02x LCD detected, %d data lines\n",
563 			md->panel.name, md->revision, md->panel.data_lines);
564 
565 	return 0;
566 }
567 
568 static int mipid_spi_probe(struct spi_device *spi)
569 {
570 	struct mipid_device *md;
571 	int r;
572 
573 	md = kzalloc(sizeof(*md), GFP_KERNEL);
574 	if (md == NULL) {
575 		dev_err(&spi->dev, "out of memory\n");
576 		return -ENOMEM;
577 	}
578 
579 	spi->mode = SPI_MODE_0;
580 	md->spi = spi;
581 	dev_set_drvdata(&spi->dev, md);
582 	md->panel = mipid_panel;
583 
584 	r = mipid_detect(md);
585 	if (r < 0)
586 		return r;
587 
588 	omapfb_register_panel(&md->panel);
589 
590 	return 0;
591 }
592 
593 static int mipid_spi_remove(struct spi_device *spi)
594 {
595 	struct mipid_device *md = dev_get_drvdata(&spi->dev);
596 
597 	mipid_disable(&md->panel);
598 	kfree(md);
599 
600 	return 0;
601 }
602 
603 static struct spi_driver mipid_spi_driver = {
604 	.driver = {
605 		.name	= MIPID_MODULE_NAME,
606 		.owner	= THIS_MODULE,
607 	},
608 	.probe	= mipid_spi_probe,
609 	.remove	= mipid_spi_remove,
610 };
611 
612 module_spi_driver(mipid_spi_driver);
613 
614 MODULE_DESCRIPTION("MIPI display driver");
615 MODULE_LICENSE("GPL");
616