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)
49struct 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
68static 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
125static inline void mipid_cmd(struct mipid_device *md, int cmd)
126{
127	mipid_transfer(md, cmd, NULL, 0, NULL, 0);
128}
129
130static 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
136static 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
142static 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
160static 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
168static 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
174static 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
184static 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
206static 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
213static 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
231static 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
241static 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
252static unsigned long mipid_get_caps(struct lcd_panel *panel)
253{
254	return OMAPFB_CAPS_SET_BACKLIGHT;
255}
256
257static 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
285static 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
324static 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
331static 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
347static 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
383static 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
390static 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
397static 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
403static 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
414static 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
435static 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
459static 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
473static 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
497static 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
506static 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
531static 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
568static 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
593static 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
603static 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
612module_spi_driver(mipid_spi_driver);
613
614MODULE_DESCRIPTION("MIPI display driver");
615MODULE_LICENSE("GPL");
616