xref: /openbmc/linux/drivers/video/fbdev/omap/sossi.c (revision 3a2699cf)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * OMAP1 Special OptimiSed Screen Interface support
4  *
5  * Copyright (C) 2004-2005 Nokia Corporation
6  * Author: Juha Yrjölä <juha.yrjola@nokia.com>
7  */
8 #include <linux/module.h>
9 #include <linux/mm.h>
10 #include <linux/clk.h>
11 #include <linux/irq.h>
12 #include <linux/io.h>
13 #include <linux/interrupt.h>
14 
15 #include <linux/omap-dma.h>
16 
17 #include "omapfb.h"
18 #include "lcdc.h"
19 
20 #define MODULE_NAME		"omapfb-sossi"
21 
22 #define OMAP_SOSSI_BASE         0xfffbac00
23 #define SOSSI_ID_REG		0x00
24 #define SOSSI_INIT1_REG		0x04
25 #define SOSSI_INIT2_REG		0x08
26 #define SOSSI_INIT3_REG		0x0c
27 #define SOSSI_FIFO_REG		0x10
28 #define SOSSI_REOTABLE_REG	0x14
29 #define SOSSI_TEARING_REG	0x18
30 #define SOSSI_INIT1B_REG	0x1c
31 #define SOSSI_FIFOB_REG		0x20
32 
33 #define DMA_GSCR          0xfffedc04
34 #define DMA_LCD_CCR       0xfffee3c2
35 #define DMA_LCD_CTRL      0xfffee3c4
36 #define DMA_LCD_LCH_CTRL  0xfffee3ea
37 
38 #define CONF_SOSSI_RESET_R      (1 << 23)
39 
40 #define RD_ACCESS		0
41 #define WR_ACCESS		1
42 
43 #define SOSSI_MAX_XMIT_BYTES	(512 * 1024)
44 
45 static struct {
46 	void __iomem	*base;
47 	struct clk	*fck;
48 	unsigned long	fck_hz;
49 	spinlock_t	lock;
50 	int		bus_pick_count;
51 	int		bus_pick_width;
52 	int		tearsync_mode;
53 	int		tearsync_line;
54 	void		(*lcdc_callback)(void *data);
55 	void		*lcdc_callback_data;
56 	int		vsync_dma_pending;
57 	/* timing for read and write access */
58 	int		clk_div;
59 	u8		clk_tw0[2];
60 	u8		clk_tw1[2];
61 	/*
62 	 * if last_access is the same as current we don't have to change
63 	 * the timings
64 	 */
65 	int		last_access;
66 
67 	struct omapfb_device	*fbdev;
68 } sossi;
69 
70 static inline u32 sossi_read_reg(int reg)
71 {
72 	return readl(sossi.base + reg);
73 }
74 
75 static inline u16 sossi_read_reg16(int reg)
76 {
77 	return readw(sossi.base + reg);
78 }
79 
80 static inline u8 sossi_read_reg8(int reg)
81 {
82 	return readb(sossi.base + reg);
83 }
84 
85 static inline void sossi_write_reg(int reg, u32 value)
86 {
87 	writel(value, sossi.base + reg);
88 }
89 
90 static inline void sossi_write_reg16(int reg, u16 value)
91 {
92 	writew(value, sossi.base + reg);
93 }
94 
95 static inline void sossi_write_reg8(int reg, u8 value)
96 {
97 	writeb(value, sossi.base + reg);
98 }
99 
100 static void sossi_set_bits(int reg, u32 bits)
101 {
102 	sossi_write_reg(reg, sossi_read_reg(reg) | bits);
103 }
104 
105 static void sossi_clear_bits(int reg, u32 bits)
106 {
107 	sossi_write_reg(reg, sossi_read_reg(reg) & ~bits);
108 }
109 
110 #define HZ_TO_PS(x)	(1000000000 / (x / 1000))
111 
112 static u32 ps_to_sossi_ticks(u32 ps, int div)
113 {
114 	u32 clk_period = HZ_TO_PS(sossi.fck_hz) * div;
115 	return (clk_period + ps - 1) / clk_period;
116 }
117 
118 static int calc_rd_timings(struct extif_timings *t)
119 {
120 	u32 tw0, tw1;
121 	int reon, reoff, recyc, actim;
122 	int div = t->clk_div;
123 
124 	/*
125 	 * Make sure that after conversion it still holds that:
126 	 * reoff > reon, recyc >= reoff, actim > reon
127 	 */
128 	reon = ps_to_sossi_ticks(t->re_on_time, div);
129 	/* reon will be exactly one sossi tick */
130 	if (reon > 1)
131 		return -1;
132 
133 	reoff = ps_to_sossi_ticks(t->re_off_time, div);
134 
135 	if (reoff <= reon)
136 		reoff = reon + 1;
137 
138 	tw0 = reoff - reon;
139 	if (tw0 > 0x10)
140 		return -1;
141 
142 	recyc = ps_to_sossi_ticks(t->re_cycle_time, div);
143 	if (recyc <= reoff)
144 		recyc = reoff + 1;
145 
146 	tw1 = recyc - tw0;
147 	/* values less then 3 result in the SOSSI block resetting itself */
148 	if (tw1 < 3)
149 		tw1 = 3;
150 	if (tw1 > 0x40)
151 		return -1;
152 
153 	actim = ps_to_sossi_ticks(t->access_time, div);
154 	if (actim < reoff)
155 		actim++;
156 	/*
157 	 * access time (data hold time) will be exactly one sossi
158 	 * tick
159 	 */
160 	if (actim - reoff > 1)
161 		return -1;
162 
163 	t->tim[0] = tw0 - 1;
164 	t->tim[1] = tw1 - 1;
165 
166 	return 0;
167 }
168 
169 static int calc_wr_timings(struct extif_timings *t)
170 {
171 	u32 tw0, tw1;
172 	int weon, weoff, wecyc;
173 	int div = t->clk_div;
174 
175 	/*
176 	 * Make sure that after conversion it still holds that:
177 	 * weoff > weon, wecyc >= weoff
178 	 */
179 	weon = ps_to_sossi_ticks(t->we_on_time, div);
180 	/* weon will be exactly one sossi tick */
181 	if (weon > 1)
182 		return -1;
183 
184 	weoff = ps_to_sossi_ticks(t->we_off_time, div);
185 	if (weoff <= weon)
186 		weoff = weon + 1;
187 	tw0 = weoff - weon;
188 	if (tw0 > 0x10)
189 		return -1;
190 
191 	wecyc = ps_to_sossi_ticks(t->we_cycle_time, div);
192 	if (wecyc <= weoff)
193 		wecyc = weoff + 1;
194 
195 	tw1 = wecyc - tw0;
196 	/* values less then 3 result in the SOSSI block resetting itself */
197 	if (tw1 < 3)
198 		tw1 = 3;
199 	if (tw1 > 0x40)
200 		return -1;
201 
202 	t->tim[2] = tw0 - 1;
203 	t->tim[3] = tw1 - 1;
204 
205 	return 0;
206 }
207 
208 static void _set_timing(int div, int tw0, int tw1)
209 {
210 	u32 l;
211 
212 #ifdef VERBOSE
213 	dev_dbg(sossi.fbdev->dev, "Using TW0 = %d, TW1 = %d, div = %d\n",
214 		 tw0 + 1, tw1 + 1, div);
215 #endif
216 
217 	clk_set_rate(sossi.fck, sossi.fck_hz / div);
218 	clk_enable(sossi.fck);
219 	l = sossi_read_reg(SOSSI_INIT1_REG);
220 	l &= ~((0x0f << 20) | (0x3f << 24));
221 	l |= (tw0 << 20) | (tw1 << 24);
222 	sossi_write_reg(SOSSI_INIT1_REG, l);
223 	clk_disable(sossi.fck);
224 }
225 
226 static void _set_bits_per_cycle(int bus_pick_count, int bus_pick_width)
227 {
228 	u32 l;
229 
230 	l = sossi_read_reg(SOSSI_INIT3_REG);
231 	l &= ~0x3ff;
232 	l |= ((bus_pick_count - 1) << 5) | ((bus_pick_width - 1) & 0x1f);
233 	sossi_write_reg(SOSSI_INIT3_REG, l);
234 }
235 
236 static void _set_tearsync_mode(int mode, unsigned line)
237 {
238 	u32 l;
239 
240 	l = sossi_read_reg(SOSSI_TEARING_REG);
241 	l &= ~(((1 << 11) - 1) << 15);
242 	l |= line << 15;
243 	l &= ~(0x3 << 26);
244 	l |= mode << 26;
245 	sossi_write_reg(SOSSI_TEARING_REG, l);
246 	if (mode)
247 		sossi_set_bits(SOSSI_INIT2_REG, 1 << 6);	/* TE logic */
248 	else
249 		sossi_clear_bits(SOSSI_INIT2_REG, 1 << 6);
250 }
251 
252 static inline void set_timing(int access)
253 {
254 	if (access != sossi.last_access) {
255 		sossi.last_access = access;
256 		_set_timing(sossi.clk_div,
257 			    sossi.clk_tw0[access], sossi.clk_tw1[access]);
258 	}
259 }
260 
261 static void sossi_start_transfer(void)
262 {
263 	/* WE */
264 	sossi_clear_bits(SOSSI_INIT2_REG, 1 << 4);
265 	/* CS active low */
266 	sossi_clear_bits(SOSSI_INIT1_REG, 1 << 30);
267 }
268 
269 static void sossi_stop_transfer(void)
270 {
271 	/* WE */
272 	sossi_set_bits(SOSSI_INIT2_REG, 1 << 4);
273 	/* CS active low */
274 	sossi_set_bits(SOSSI_INIT1_REG, 1 << 30);
275 }
276 
277 static void wait_end_of_write(void)
278 {
279 	/* Before reading we must check if some writings are going on */
280 	while (!(sossi_read_reg(SOSSI_INIT2_REG) & (1 << 3)));
281 }
282 
283 static void send_data(const void *data, unsigned int len)
284 {
285 	while (len >= 4) {
286 		sossi_write_reg(SOSSI_FIFO_REG, *(const u32 *) data);
287 		len -= 4;
288 		data += 4;
289 	}
290 	while (len >= 2) {
291 		sossi_write_reg16(SOSSI_FIFO_REG, *(const u16 *) data);
292 		len -= 2;
293 		data += 2;
294 	}
295 	while (len) {
296 		sossi_write_reg8(SOSSI_FIFO_REG, *(const u8 *) data);
297 		len--;
298 		data++;
299 	}
300 }
301 
302 static void set_cycles(unsigned int len)
303 {
304 	unsigned long nr_cycles = len / (sossi.bus_pick_width / 8);
305 
306 	BUG_ON((nr_cycles - 1) & ~0x3ffff);
307 
308 	sossi_clear_bits(SOSSI_INIT1_REG, 0x3ffff);
309 	sossi_set_bits(SOSSI_INIT1_REG, (nr_cycles - 1) & 0x3ffff);
310 }
311 
312 static int sossi_convert_timings(struct extif_timings *t)
313 {
314 	int r = 0;
315 	int div = t->clk_div;
316 
317 	t->converted = 0;
318 
319 	if (div <= 0 || div > 8)
320 		return -1;
321 
322 	/* no CS on SOSSI, so ignore cson, csoff, cs_pulsewidth */
323 	if ((r = calc_rd_timings(t)) < 0)
324 		return r;
325 
326 	if ((r = calc_wr_timings(t)) < 0)
327 		return r;
328 
329 	t->tim[4] = div;
330 
331 	t->converted = 1;
332 
333 	return 0;
334 }
335 
336 static void sossi_set_timings(const struct extif_timings *t)
337 {
338 	BUG_ON(!t->converted);
339 
340 	sossi.clk_tw0[RD_ACCESS] = t->tim[0];
341 	sossi.clk_tw1[RD_ACCESS] = t->tim[1];
342 
343 	sossi.clk_tw0[WR_ACCESS] = t->tim[2];
344 	sossi.clk_tw1[WR_ACCESS] = t->tim[3];
345 
346 	sossi.clk_div = t->tim[4];
347 }
348 
349 static void sossi_get_clk_info(u32 *clk_period, u32 *max_clk_div)
350 {
351 	*clk_period = HZ_TO_PS(sossi.fck_hz);
352 	*max_clk_div = 8;
353 }
354 
355 static void sossi_set_bits_per_cycle(int bpc)
356 {
357 	int bus_pick_count, bus_pick_width;
358 
359 	/*
360 	 * We set explicitly the the bus_pick_count as well, although
361 	 * with remapping/reordering disabled it will be calculated by HW
362 	 * as (32 / bus_pick_width).
363 	 */
364 	switch (bpc) {
365 	case 8:
366 		bus_pick_count = 4;
367 		bus_pick_width = 8;
368 		break;
369 	case 16:
370 		bus_pick_count = 2;
371 		bus_pick_width = 16;
372 		break;
373 	default:
374 		BUG();
375 		return;
376 	}
377 	sossi.bus_pick_width = bus_pick_width;
378 	sossi.bus_pick_count = bus_pick_count;
379 }
380 
381 static int sossi_setup_tearsync(unsigned pin_cnt,
382 				unsigned hs_pulse_time, unsigned vs_pulse_time,
383 				int hs_pol_inv, int vs_pol_inv, int div)
384 {
385 	int hs, vs;
386 	u32 l;
387 
388 	if (pin_cnt != 1 || div < 1 || div > 8)
389 		return -EINVAL;
390 
391 	hs = ps_to_sossi_ticks(hs_pulse_time, div);
392 	vs = ps_to_sossi_ticks(vs_pulse_time, div);
393 	if (vs < 8 || vs <= hs || vs >= (1 << 12))
394 		return -EDOM;
395 	vs /= 8;
396 	vs--;
397 	if (hs > 8)
398 		hs = 8;
399 	if (hs)
400 		hs--;
401 
402 	dev_dbg(sossi.fbdev->dev,
403 		"setup_tearsync: hs %d vs %d hs_inv %d vs_inv %d\n",
404 		hs, vs, hs_pol_inv, vs_pol_inv);
405 
406 	clk_enable(sossi.fck);
407 	l = sossi_read_reg(SOSSI_TEARING_REG);
408 	l &= ~((1 << 15) - 1);
409 	l |= vs << 3;
410 	l |= hs;
411 	if (hs_pol_inv)
412 		l |= 1 << 29;
413 	else
414 		l &= ~(1 << 29);
415 	if (vs_pol_inv)
416 		l |= 1 << 28;
417 	else
418 		l &= ~(1 << 28);
419 	sossi_write_reg(SOSSI_TEARING_REG, l);
420 	clk_disable(sossi.fck);
421 
422 	return 0;
423 }
424 
425 static int sossi_enable_tearsync(int enable, unsigned line)
426 {
427 	int mode;
428 
429 	dev_dbg(sossi.fbdev->dev, "tearsync %d line %d\n", enable, line);
430 	if (line >= 1 << 11)
431 		return -EINVAL;
432 	if (enable) {
433 		if (line)
434 			mode = 2;		/* HS or VS */
435 		else
436 			mode = 3;		/* VS only */
437 	} else
438 		mode = 0;
439 	sossi.tearsync_line = line;
440 	sossi.tearsync_mode = mode;
441 
442 	return 0;
443 }
444 
445 static void sossi_write_command(const void *data, unsigned int len)
446 {
447 	clk_enable(sossi.fck);
448 	set_timing(WR_ACCESS);
449 	_set_bits_per_cycle(sossi.bus_pick_count, sossi.bus_pick_width);
450 	/* CMD#/DATA */
451 	sossi_clear_bits(SOSSI_INIT1_REG, 1 << 18);
452 	set_cycles(len);
453 	sossi_start_transfer();
454 	send_data(data, len);
455 	sossi_stop_transfer();
456 	wait_end_of_write();
457 	clk_disable(sossi.fck);
458 }
459 
460 static void sossi_write_data(const void *data, unsigned int len)
461 {
462 	clk_enable(sossi.fck);
463 	set_timing(WR_ACCESS);
464 	_set_bits_per_cycle(sossi.bus_pick_count, sossi.bus_pick_width);
465 	/* CMD#/DATA */
466 	sossi_set_bits(SOSSI_INIT1_REG, 1 << 18);
467 	set_cycles(len);
468 	sossi_start_transfer();
469 	send_data(data, len);
470 	sossi_stop_transfer();
471 	wait_end_of_write();
472 	clk_disable(sossi.fck);
473 }
474 
475 static void sossi_transfer_area(int width, int height,
476 				void (callback)(void *data), void *data)
477 {
478 	BUG_ON(callback == NULL);
479 
480 	sossi.lcdc_callback = callback;
481 	sossi.lcdc_callback_data = data;
482 
483 	clk_enable(sossi.fck);
484 	set_timing(WR_ACCESS);
485 	_set_bits_per_cycle(sossi.bus_pick_count, sossi.bus_pick_width);
486 	_set_tearsync_mode(sossi.tearsync_mode, sossi.tearsync_line);
487 	/* CMD#/DATA */
488 	sossi_set_bits(SOSSI_INIT1_REG, 1 << 18);
489 	set_cycles(width * height * sossi.bus_pick_width / 8);
490 
491 	sossi_start_transfer();
492 	if (sossi.tearsync_mode) {
493 		/*
494 		 * Wait for the sync signal and start the transfer only
495 		 * then. We can't seem to be able to use HW sync DMA for
496 		 * this since LCD DMA shows huge latencies, as if it
497 		 * would ignore some of the DMA requests from SoSSI.
498 		 */
499 		unsigned long flags;
500 
501 		spin_lock_irqsave(&sossi.lock, flags);
502 		sossi.vsync_dma_pending++;
503 		spin_unlock_irqrestore(&sossi.lock, flags);
504 	} else
505 		/* Just start the transfer right away. */
506 		omap_enable_lcd_dma();
507 }
508 
509 static void sossi_dma_callback(void *data)
510 {
511 	omap_stop_lcd_dma();
512 	sossi_stop_transfer();
513 	clk_disable(sossi.fck);
514 	sossi.lcdc_callback(sossi.lcdc_callback_data);
515 }
516 
517 static void sossi_read_data(void *data, unsigned int len)
518 {
519 	clk_enable(sossi.fck);
520 	set_timing(RD_ACCESS);
521 	_set_bits_per_cycle(sossi.bus_pick_count, sossi.bus_pick_width);
522 	/* CMD#/DATA */
523 	sossi_set_bits(SOSSI_INIT1_REG, 1 << 18);
524 	set_cycles(len);
525 	sossi_start_transfer();
526 	while (len >= 4) {
527 		*(u32 *) data = sossi_read_reg(SOSSI_FIFO_REG);
528 		len -= 4;
529 		data += 4;
530 	}
531 	while (len >= 2) {
532 		*(u16 *) data = sossi_read_reg16(SOSSI_FIFO_REG);
533 		len -= 2;
534 		data += 2;
535 	}
536 	while (len) {
537 		*(u8 *) data = sossi_read_reg8(SOSSI_FIFO_REG);
538 		len--;
539 		data++;
540 	}
541 	sossi_stop_transfer();
542 	clk_disable(sossi.fck);
543 }
544 
545 static irqreturn_t sossi_match_irq(int irq, void *data)
546 {
547 	unsigned long flags;
548 
549 	spin_lock_irqsave(&sossi.lock, flags);
550 	if (sossi.vsync_dma_pending) {
551 		sossi.vsync_dma_pending--;
552 		omap_enable_lcd_dma();
553 	}
554 	spin_unlock_irqrestore(&sossi.lock, flags);
555 	return IRQ_HANDLED;
556 }
557 
558 static int sossi_init(struct omapfb_device *fbdev)
559 {
560 	u32 l, k;
561 	struct clk *fck;
562 	struct clk *dpll1out_ck;
563 	int r;
564 
565 	sossi.base = ioremap(OMAP_SOSSI_BASE, SZ_1K);
566 	if (!sossi.base) {
567 		dev_err(fbdev->dev, "can't ioremap SoSSI\n");
568 		return -ENOMEM;
569 	}
570 
571 	sossi.fbdev = fbdev;
572 	spin_lock_init(&sossi.lock);
573 
574 	dpll1out_ck = clk_get(fbdev->dev, "ck_dpll1out");
575 	if (IS_ERR(dpll1out_ck)) {
576 		dev_err(fbdev->dev, "can't get DPLL1OUT clock\n");
577 		return PTR_ERR(dpll1out_ck);
578 	}
579 	/*
580 	 * We need the parent clock rate, which we might divide further
581 	 * depending on the timing requirements of the controller. See
582 	 * _set_timings.
583 	 */
584 	sossi.fck_hz = clk_get_rate(dpll1out_ck);
585 	clk_put(dpll1out_ck);
586 
587 	fck = clk_get(fbdev->dev, "ck_sossi");
588 	if (IS_ERR(fck)) {
589 		dev_err(fbdev->dev, "can't get SoSSI functional clock\n");
590 		return PTR_ERR(fck);
591 	}
592 	sossi.fck = fck;
593 
594 	/* Reset and enable the SoSSI module */
595 	l = omap_readl(MOD_CONF_CTRL_1);
596 	l |= CONF_SOSSI_RESET_R;
597 	omap_writel(l, MOD_CONF_CTRL_1);
598 	l &= ~CONF_SOSSI_RESET_R;
599 	omap_writel(l, MOD_CONF_CTRL_1);
600 
601 	clk_prepare_enable(sossi.fck);
602 	l = omap_readl(ARM_IDLECT2);
603 	l &= ~(1 << 8);			/* DMACK_REQ */
604 	omap_writel(l, ARM_IDLECT2);
605 
606 	l = sossi_read_reg(SOSSI_INIT2_REG);
607 	/* Enable and reset the SoSSI block */
608 	l |= (1 << 0) | (1 << 1);
609 	sossi_write_reg(SOSSI_INIT2_REG, l);
610 	/* Take SoSSI out of reset */
611 	l &= ~(1 << 1);
612 	sossi_write_reg(SOSSI_INIT2_REG, l);
613 
614 	sossi_write_reg(SOSSI_ID_REG, 0);
615 	l = sossi_read_reg(SOSSI_ID_REG);
616 	k = sossi_read_reg(SOSSI_ID_REG);
617 
618 	if (l != 0x55555555 || k != 0xaaaaaaaa) {
619 		dev_err(fbdev->dev,
620 			"invalid SoSSI sync pattern: %08x, %08x\n", l, k);
621 		r = -ENODEV;
622 		goto err;
623 	}
624 
625 	if ((r = omap_lcdc_set_dma_callback(sossi_dma_callback, NULL)) < 0) {
626 		dev_err(fbdev->dev, "can't get LCDC IRQ\n");
627 		r = -ENODEV;
628 		goto err;
629 	}
630 
631 	l = sossi_read_reg(SOSSI_ID_REG); /* Component code */
632 	l = sossi_read_reg(SOSSI_ID_REG);
633 	dev_info(fbdev->dev, "SoSSI version %d.%d initialized\n",
634 		l >> 16, l & 0xffff);
635 
636 	l = sossi_read_reg(SOSSI_INIT1_REG);
637 	l |= (1 << 19); /* DMA_MODE */
638 	l &= ~(1 << 31); /* REORDERING */
639 	sossi_write_reg(SOSSI_INIT1_REG, l);
640 
641 	if ((r = request_irq(INT_1610_SoSSI_MATCH, sossi_match_irq,
642 			     IRQ_TYPE_EDGE_FALLING,
643 	     "sossi_match", sossi.fbdev->dev)) < 0) {
644 		dev_err(sossi.fbdev->dev, "can't get SoSSI match IRQ\n");
645 		goto err;
646 	}
647 
648 	clk_disable(sossi.fck);
649 	return 0;
650 
651 err:
652 	clk_disable_unprepare(sossi.fck);
653 	clk_put(sossi.fck);
654 	return r;
655 }
656 
657 static void sossi_cleanup(void)
658 {
659 	omap_lcdc_free_dma_callback();
660 	clk_unprepare(sossi.fck);
661 	clk_put(sossi.fck);
662 	iounmap(sossi.base);
663 }
664 
665 struct lcd_ctrl_extif omap1_ext_if = {
666 	.init			= sossi_init,
667 	.cleanup		= sossi_cleanup,
668 	.get_clk_info		= sossi_get_clk_info,
669 	.convert_timings	= sossi_convert_timings,
670 	.set_timings		= sossi_set_timings,
671 	.set_bits_per_cycle	= sossi_set_bits_per_cycle,
672 	.setup_tearsync		= sossi_setup_tearsync,
673 	.enable_tearsync	= sossi_enable_tearsync,
674 	.write_command		= sossi_write_command,
675 	.read_data		= sossi_read_data,
676 	.write_data		= sossi_write_data,
677 	.transfer_area		= sossi_transfer_area,
678 
679 	.max_transmit_size	= SOSSI_MAX_XMIT_BYTES,
680 };
681 
682