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#include <linux/soc/ti/omap1-io.h>
17
18#include "omapfb.h"
19#include "lcd_dma.h"
20#include "lcdc.h"
21
22#define MODULE_NAME "omapfb-sossi"
23
24#define OMAP_SOSSI_BASE 0xfffbac00
25#define SOSSI_ID_REG 0x00
26#define SOSSI_INIT1_REG 0x04
27#define SOSSI_INIT2_REG 0x08
28#define SOSSI_INIT3_REG 0x0c
29#define SOSSI_FIFO_REG 0x10
30#define SOSSI_REOTABLE_REG 0x14
31#define SOSSI_TEARING_REG 0x18
32#define SOSSI_INIT1B_REG 0x1c
33#define SOSSI_FIFOB_REG 0x20
34
35#define DMA_GSCR 0xfffedc04
36#define DMA_LCD_CCR 0xfffee3c2
37#define DMA_LCD_CTRL 0xfffee3c4
38#define DMA_LCD_LCH_CTRL 0xfffee3ea
39
40#define CONF_SOSSI_RESET_R (1 << 23)
41
42#define RD_ACCESS 0
43#define WR_ACCESS 1
44
45#define SOSSI_MAX_XMIT_BYTES (512 * 1024)
46
47static struct {
48 void __iomem *base;
49 struct clk *fck;
50 unsigned long fck_hz;
51 spinlock_t lock;
52 int bus_pick_count;
53 int bus_pick_width;
54 int tearsync_mode;
55 int tearsync_line;
56 void (*lcdc_callback)(void *data);
57 void *lcdc_callback_data;
58 int vsync_dma_pending;
59 /* timing for read and write access */
60 int clk_div;
61 u8 clk_tw0[2];
62 u8 clk_tw1[2];
63 /*
64 * if last_access is the same as current we don't have to change
65 * the timings
66 */
67 int last_access;
68
69 struct omapfb_device *fbdev;
70} sossi;
71
72static inline u32 sossi_read_reg(int reg)
73{
74 return readl(addr: sossi.base + reg);
75}
76
77static inline u16 sossi_read_reg16(int reg)
78{
79 return readw(addr: sossi.base + reg);
80}
81
82static inline u8 sossi_read_reg8(int reg)
83{
84 return readb(addr: sossi.base + reg);
85}
86
87static inline void sossi_write_reg(int reg, u32 value)
88{
89 writel(val: value, addr: sossi.base + reg);
90}
91
92static inline void sossi_write_reg16(int reg, u16 value)
93{
94 writew(val: value, addr: sossi.base + reg);
95}
96
97static inline void sossi_write_reg8(int reg, u8 value)
98{
99 writeb(val: value, addr: sossi.base + reg);
100}
101
102static void sossi_set_bits(int reg, u32 bits)
103{
104 sossi_write_reg(reg, value: sossi_read_reg(reg) | bits);
105}
106
107static void sossi_clear_bits(int reg, u32 bits)
108{
109 sossi_write_reg(reg, value: sossi_read_reg(reg) & ~bits);
110}
111
112#define HZ_TO_PS(x) (1000000000 / (x / 1000))
113
114static u32 ps_to_sossi_ticks(u32 ps, int div)
115{
116 u32 clk_period = HZ_TO_PS(sossi.fck_hz) * div;
117 return (clk_period + ps - 1) / clk_period;
118}
119
120static int calc_rd_timings(struct extif_timings *t)
121{
122 u32 tw0, tw1;
123 int reon, reoff, recyc, actim;
124 int div = t->clk_div;
125
126 /*
127 * Make sure that after conversion it still holds that:
128 * reoff > reon, recyc >= reoff, actim > reon
129 */
130 reon = ps_to_sossi_ticks(ps: t->re_on_time, div);
131 /* reon will be exactly one sossi tick */
132 if (reon > 1)
133 return -1;
134
135 reoff = ps_to_sossi_ticks(ps: t->re_off_time, div);
136
137 if (reoff <= reon)
138 reoff = reon + 1;
139
140 tw0 = reoff - reon;
141 if (tw0 > 0x10)
142 return -1;
143
144 recyc = ps_to_sossi_ticks(ps: t->re_cycle_time, div);
145 if (recyc <= reoff)
146 recyc = reoff + 1;
147
148 tw1 = recyc - tw0;
149 /* values less then 3 result in the SOSSI block resetting itself */
150 if (tw1 < 3)
151 tw1 = 3;
152 if (tw1 > 0x40)
153 return -1;
154
155 actim = ps_to_sossi_ticks(ps: t->access_time, div);
156 if (actim < reoff)
157 actim++;
158 /*
159 * access time (data hold time) will be exactly one sossi
160 * tick
161 */
162 if (actim - reoff > 1)
163 return -1;
164
165 t->tim[0] = tw0 - 1;
166 t->tim[1] = tw1 - 1;
167
168 return 0;
169}
170
171static int calc_wr_timings(struct extif_timings *t)
172{
173 u32 tw0, tw1;
174 int weon, weoff, wecyc;
175 int div = t->clk_div;
176
177 /*
178 * Make sure that after conversion it still holds that:
179 * weoff > weon, wecyc >= weoff
180 */
181 weon = ps_to_sossi_ticks(ps: t->we_on_time, div);
182 /* weon will be exactly one sossi tick */
183 if (weon > 1)
184 return -1;
185
186 weoff = ps_to_sossi_ticks(ps: t->we_off_time, div);
187 if (weoff <= weon)
188 weoff = weon + 1;
189 tw0 = weoff - weon;
190 if (tw0 > 0x10)
191 return -1;
192
193 wecyc = ps_to_sossi_ticks(ps: t->we_cycle_time, div);
194 if (wecyc <= weoff)
195 wecyc = weoff + 1;
196
197 tw1 = wecyc - tw0;
198 /* values less then 3 result in the SOSSI block resetting itself */
199 if (tw1 < 3)
200 tw1 = 3;
201 if (tw1 > 0x40)
202 return -1;
203
204 t->tim[2] = tw0 - 1;
205 t->tim[3] = tw1 - 1;
206
207 return 0;
208}
209
210static void _set_timing(int div, int tw0, int tw1)
211{
212 u32 l;
213
214#ifdef VERBOSE
215 dev_dbg(sossi.fbdev->dev, "Using TW0 = %d, TW1 = %d, div = %d\n",
216 tw0 + 1, tw1 + 1, div);
217#endif
218
219 clk_set_rate(clk: sossi.fck, rate: sossi.fck_hz / div);
220 clk_enable(clk: sossi.fck);
221 l = sossi_read_reg(SOSSI_INIT1_REG);
222 l &= ~((0x0f << 20) | (0x3f << 24));
223 l |= (tw0 << 20) | (tw1 << 24);
224 sossi_write_reg(SOSSI_INIT1_REG, value: l);
225 clk_disable(clk: sossi.fck);
226}
227
228static void _set_bits_per_cycle(int bus_pick_count, int bus_pick_width)
229{
230 u32 l;
231
232 l = sossi_read_reg(SOSSI_INIT3_REG);
233 l &= ~0x3ff;
234 l |= ((bus_pick_count - 1) << 5) | ((bus_pick_width - 1) & 0x1f);
235 sossi_write_reg(SOSSI_INIT3_REG, value: l);
236}
237
238static void _set_tearsync_mode(int mode, unsigned line)
239{
240 u32 l;
241
242 l = sossi_read_reg(SOSSI_TEARING_REG);
243 l &= ~(((1 << 11) - 1) << 15);
244 l |= line << 15;
245 l &= ~(0x3 << 26);
246 l |= mode << 26;
247 sossi_write_reg(SOSSI_TEARING_REG, value: l);
248 if (mode)
249 sossi_set_bits(SOSSI_INIT2_REG, bits: 1 << 6); /* TE logic */
250 else
251 sossi_clear_bits(SOSSI_INIT2_REG, bits: 1 << 6);
252}
253
254static inline void set_timing(int access)
255{
256 if (access != sossi.last_access) {
257 sossi.last_access = access;
258 _set_timing(div: sossi.clk_div,
259 tw0: sossi.clk_tw0[access], tw1: sossi.clk_tw1[access]);
260 }
261}
262
263static void sossi_start_transfer(void)
264{
265 /* WE */
266 sossi_clear_bits(SOSSI_INIT2_REG, bits: 1 << 4);
267 /* CS active low */
268 sossi_clear_bits(SOSSI_INIT1_REG, bits: 1 << 30);
269}
270
271static void sossi_stop_transfer(void)
272{
273 /* WE */
274 sossi_set_bits(SOSSI_INIT2_REG, bits: 1 << 4);
275 /* CS active low */
276 sossi_set_bits(SOSSI_INIT1_REG, bits: 1 << 30);
277}
278
279static void wait_end_of_write(void)
280{
281 /* Before reading we must check if some writings are going on */
282 while (!(sossi_read_reg(SOSSI_INIT2_REG) & (1 << 3)));
283}
284
285static void send_data(const void *data, unsigned int len)
286{
287 while (len >= 4) {
288 sossi_write_reg(SOSSI_FIFO_REG, value: *(const u32 *) data);
289 len -= 4;
290 data += 4;
291 }
292 while (len >= 2) {
293 sossi_write_reg16(SOSSI_FIFO_REG, value: *(const u16 *) data);
294 len -= 2;
295 data += 2;
296 }
297 while (len) {
298 sossi_write_reg8(SOSSI_FIFO_REG, value: *(const u8 *) data);
299 len--;
300 data++;
301 }
302}
303
304static void set_cycles(unsigned int len)
305{
306 unsigned long nr_cycles = len / (sossi.bus_pick_width / 8);
307
308 BUG_ON((nr_cycles - 1) & ~0x3ffff);
309
310 sossi_clear_bits(SOSSI_INIT1_REG, bits: 0x3ffff);
311 sossi_set_bits(SOSSI_INIT1_REG, bits: (nr_cycles - 1) & 0x3ffff);
312}
313
314static int sossi_convert_timings(struct extif_timings *t)
315{
316 int r = 0;
317 int div = t->clk_div;
318
319 t->converted = 0;
320
321 if (div <= 0 || div > 8)
322 return -1;
323
324 /* no CS on SOSSI, so ignore cson, csoff, cs_pulsewidth */
325 if ((r = calc_rd_timings(t)) < 0)
326 return r;
327
328 if ((r = calc_wr_timings(t)) < 0)
329 return r;
330
331 t->tim[4] = div;
332
333 t->converted = 1;
334
335 return 0;
336}
337
338static void sossi_set_timings(const struct extif_timings *t)
339{
340 BUG_ON(!t->converted);
341
342 sossi.clk_tw0[RD_ACCESS] = t->tim[0];
343 sossi.clk_tw1[RD_ACCESS] = t->tim[1];
344
345 sossi.clk_tw0[WR_ACCESS] = t->tim[2];
346 sossi.clk_tw1[WR_ACCESS] = t->tim[3];
347
348 sossi.clk_div = t->tim[4];
349}
350
351static void sossi_get_clk_info(u32 *clk_period, u32 *max_clk_div)
352{
353 *clk_period = HZ_TO_PS(sossi.fck_hz);
354 *max_clk_div = 8;
355}
356
357static void sossi_set_bits_per_cycle(int bpc)
358{
359 int bus_pick_count, bus_pick_width;
360
361 /*
362 * We set explicitly the bus_pick_count as well, although
363 * with remapping/reordering disabled it will be calculated by HW
364 * as (32 / bus_pick_width).
365 */
366 switch (bpc) {
367 case 8:
368 bus_pick_count = 4;
369 bus_pick_width = 8;
370 break;
371 case 16:
372 bus_pick_count = 2;
373 bus_pick_width = 16;
374 break;
375 default:
376 BUG();
377 return;
378 }
379 sossi.bus_pick_width = bus_pick_width;
380 sossi.bus_pick_count = bus_pick_count;
381}
382
383static int sossi_setup_tearsync(unsigned pin_cnt,
384 unsigned hs_pulse_time, unsigned vs_pulse_time,
385 int hs_pol_inv, int vs_pol_inv, int div)
386{
387 int hs, vs;
388 u32 l;
389
390 if (pin_cnt != 1 || div < 1 || div > 8)
391 return -EINVAL;
392
393 hs = ps_to_sossi_ticks(ps: hs_pulse_time, div);
394 vs = ps_to_sossi_ticks(ps: vs_pulse_time, div);
395 if (vs < 8 || vs <= hs || vs >= (1 << 12))
396 return -EDOM;
397 vs /= 8;
398 vs--;
399 if (hs > 8)
400 hs = 8;
401 if (hs)
402 hs--;
403
404 dev_dbg(sossi.fbdev->dev,
405 "setup_tearsync: hs %d vs %d hs_inv %d vs_inv %d\n",
406 hs, vs, hs_pol_inv, vs_pol_inv);
407
408 clk_enable(clk: sossi.fck);
409 l = sossi_read_reg(SOSSI_TEARING_REG);
410 l &= ~((1 << 15) - 1);
411 l |= vs << 3;
412 l |= hs;
413 if (hs_pol_inv)
414 l |= 1 << 29;
415 else
416 l &= ~(1 << 29);
417 if (vs_pol_inv)
418 l |= 1 << 28;
419 else
420 l &= ~(1 << 28);
421 sossi_write_reg(SOSSI_TEARING_REG, value: l);
422 clk_disable(clk: sossi.fck);
423
424 return 0;
425}
426
427static int sossi_enable_tearsync(int enable, unsigned line)
428{
429 int mode;
430
431 dev_dbg(sossi.fbdev->dev, "tearsync %d line %d\n", enable, line);
432 if (line >= 1 << 11)
433 return -EINVAL;
434 if (enable) {
435 if (line)
436 mode = 2; /* HS or VS */
437 else
438 mode = 3; /* VS only */
439 } else
440 mode = 0;
441 sossi.tearsync_line = line;
442 sossi.tearsync_mode = mode;
443
444 return 0;
445}
446
447static void sossi_write_command(const void *data, unsigned int len)
448{
449 clk_enable(clk: sossi.fck);
450 set_timing(WR_ACCESS);
451 _set_bits_per_cycle(bus_pick_count: sossi.bus_pick_count, bus_pick_width: sossi.bus_pick_width);
452 /* CMD#/DATA */
453 sossi_clear_bits(SOSSI_INIT1_REG, bits: 1 << 18);
454 set_cycles(len);
455 sossi_start_transfer();
456 send_data(data, len);
457 sossi_stop_transfer();
458 wait_end_of_write();
459 clk_disable(clk: sossi.fck);
460}
461
462static void sossi_write_data(const void *data, unsigned int len)
463{
464 clk_enable(clk: sossi.fck);
465 set_timing(WR_ACCESS);
466 _set_bits_per_cycle(bus_pick_count: sossi.bus_pick_count, bus_pick_width: sossi.bus_pick_width);
467 /* CMD#/DATA */
468 sossi_set_bits(SOSSI_INIT1_REG, bits: 1 << 18);
469 set_cycles(len);
470 sossi_start_transfer();
471 send_data(data, len);
472 sossi_stop_transfer();
473 wait_end_of_write();
474 clk_disable(clk: sossi.fck);
475}
476
477static void sossi_transfer_area(int width, int height,
478 void (callback)(void *data), void *data)
479{
480 BUG_ON(callback == NULL);
481
482 sossi.lcdc_callback = callback;
483 sossi.lcdc_callback_data = data;
484
485 clk_enable(clk: sossi.fck);
486 set_timing(WR_ACCESS);
487 _set_bits_per_cycle(bus_pick_count: sossi.bus_pick_count, bus_pick_width: sossi.bus_pick_width);
488 _set_tearsync_mode(mode: sossi.tearsync_mode, line: sossi.tearsync_line);
489 /* CMD#/DATA */
490 sossi_set_bits(SOSSI_INIT1_REG, bits: 1 << 18);
491 set_cycles(width * height * sossi.bus_pick_width / 8);
492
493 sossi_start_transfer();
494 if (sossi.tearsync_mode) {
495 /*
496 * Wait for the sync signal and start the transfer only
497 * then. We can't seem to be able to use HW sync DMA for
498 * this since LCD DMA shows huge latencies, as if it
499 * would ignore some of the DMA requests from SoSSI.
500 */
501 unsigned long flags;
502
503 spin_lock_irqsave(&sossi.lock, flags);
504 sossi.vsync_dma_pending++;
505 spin_unlock_irqrestore(lock: &sossi.lock, flags);
506 } else
507 /* Just start the transfer right away. */
508 omap_enable_lcd_dma();
509}
510
511static void sossi_dma_callback(void *data)
512{
513 omap_stop_lcd_dma();
514 sossi_stop_transfer();
515 clk_disable(clk: sossi.fck);
516 sossi.lcdc_callback(sossi.lcdc_callback_data);
517}
518
519static void sossi_read_data(void *data, unsigned int len)
520{
521 clk_enable(clk: sossi.fck);
522 set_timing(RD_ACCESS);
523 _set_bits_per_cycle(bus_pick_count: sossi.bus_pick_count, bus_pick_width: sossi.bus_pick_width);
524 /* CMD#/DATA */
525 sossi_set_bits(SOSSI_INIT1_REG, bits: 1 << 18);
526 set_cycles(len);
527 sossi_start_transfer();
528 while (len >= 4) {
529 *(u32 *) data = sossi_read_reg(SOSSI_FIFO_REG);
530 len -= 4;
531 data += 4;
532 }
533 while (len >= 2) {
534 *(u16 *) data = sossi_read_reg16(SOSSI_FIFO_REG);
535 len -= 2;
536 data += 2;
537 }
538 while (len) {
539 *(u8 *) data = sossi_read_reg8(SOSSI_FIFO_REG);
540 len--;
541 data++;
542 }
543 sossi_stop_transfer();
544 clk_disable(clk: sossi.fck);
545}
546
547static irqreturn_t sossi_match_irq(int irq, void *data)
548{
549 unsigned long flags;
550
551 spin_lock_irqsave(&sossi.lock, flags);
552 if (sossi.vsync_dma_pending) {
553 sossi.vsync_dma_pending--;
554 omap_enable_lcd_dma();
555 }
556 spin_unlock_irqrestore(lock: &sossi.lock, flags);
557 return IRQ_HANDLED;
558}
559
560static int sossi_init(struct omapfb_device *fbdev)
561{
562 u32 l, k;
563 struct clk *fck;
564 struct clk *dpll1out_ck;
565 int r;
566
567 sossi.base = ioremap(OMAP_SOSSI_BASE, SZ_1K);
568 if (!sossi.base) {
569 dev_err(fbdev->dev, "can't ioremap SoSSI\n");
570 return -ENOMEM;
571 }
572
573 sossi.fbdev = fbdev;
574 spin_lock_init(&sossi.lock);
575
576 dpll1out_ck = clk_get(dev: fbdev->dev, id: "ck_dpll1out");
577 if (IS_ERR(ptr: dpll1out_ck)) {
578 dev_err(fbdev->dev, "can't get DPLL1OUT clock\n");
579 return PTR_ERR(ptr: dpll1out_ck);
580 }
581 /*
582 * We need the parent clock rate, which we might divide further
583 * depending on the timing requirements of the controller. See
584 * _set_timings.
585 */
586 sossi.fck_hz = clk_get_rate(clk: dpll1out_ck);
587 clk_put(clk: dpll1out_ck);
588
589 fck = clk_get(dev: fbdev->dev, id: "ck_sossi");
590 if (IS_ERR(ptr: fck)) {
591 dev_err(fbdev->dev, "can't get SoSSI functional clock\n");
592 return PTR_ERR(ptr: fck);
593 }
594 sossi.fck = fck;
595
596 /* Reset and enable the SoSSI module */
597 l = omap_readl(MOD_CONF_CTRL_1);
598 l |= CONF_SOSSI_RESET_R;
599 omap_writel(v: l, MOD_CONF_CTRL_1);
600 l &= ~CONF_SOSSI_RESET_R;
601 omap_writel(v: l, MOD_CONF_CTRL_1);
602
603 clk_prepare_enable(clk: sossi.fck);
604 l = omap_readl(ARM_IDLECT2);
605 l &= ~(1 << 8); /* DMACK_REQ */
606 omap_writel(v: l, ARM_IDLECT2);
607
608 l = sossi_read_reg(SOSSI_INIT2_REG);
609 /* Enable and reset the SoSSI block */
610 l |= (1 << 0) | (1 << 1);
611 sossi_write_reg(SOSSI_INIT2_REG, value: l);
612 /* Take SoSSI out of reset */
613 l &= ~(1 << 1);
614 sossi_write_reg(SOSSI_INIT2_REG, value: l);
615
616 sossi_write_reg(SOSSI_ID_REG, value: 0);
617 l = sossi_read_reg(SOSSI_ID_REG);
618 k = sossi_read_reg(SOSSI_ID_REG);
619
620 if (l != 0x55555555 || k != 0xaaaaaaaa) {
621 dev_err(fbdev->dev,
622 "invalid SoSSI sync pattern: %08x, %08x\n", l, k);
623 r = -ENODEV;
624 goto err;
625 }
626
627 if ((r = omap_lcdc_set_dma_callback(callback: sossi_dma_callback, NULL)) < 0) {
628 dev_err(fbdev->dev, "can't get LCDC IRQ\n");
629 r = -ENODEV;
630 goto err;
631 }
632
633 l = sossi_read_reg(SOSSI_ID_REG); /* Component code */
634 l = sossi_read_reg(SOSSI_ID_REG);
635 dev_info(fbdev->dev, "SoSSI version %d.%d initialized\n",
636 l >> 16, l & 0xffff);
637
638 l = sossi_read_reg(SOSSI_INIT1_REG);
639 l |= (1 << 19); /* DMA_MODE */
640 l &= ~(1 << 31); /* REORDERING */
641 sossi_write_reg(SOSSI_INIT1_REG, value: l);
642
643 if ((r = request_irq(irq: fbdev->ext_irq, handler: sossi_match_irq,
644 flags: IRQ_TYPE_EDGE_FALLING,
645 name: "sossi_match", dev: sossi.fbdev->dev)) < 0) {
646 dev_err(sossi.fbdev->dev, "can't get SoSSI match IRQ\n");
647 goto err;
648 }
649
650 clk_disable(clk: sossi.fck);
651 return 0;
652
653err:
654 clk_disable_unprepare(clk: sossi.fck);
655 clk_put(clk: sossi.fck);
656 return r;
657}
658
659static void sossi_cleanup(void)
660{
661 omap_lcdc_free_dma_callback();
662 clk_unprepare(clk: sossi.fck);
663 clk_put(clk: sossi.fck);
664 iounmap(addr: sossi.base);
665}
666
667struct lcd_ctrl_extif omap1_ext_if = {
668 .init = sossi_init,
669 .cleanup = sossi_cleanup,
670 .get_clk_info = sossi_get_clk_info,
671 .convert_timings = sossi_convert_timings,
672 .set_timings = sossi_set_timings,
673 .set_bits_per_cycle = sossi_set_bits_per_cycle,
674 .setup_tearsync = sossi_setup_tearsync,
675 .enable_tearsync = sossi_enable_tearsync,
676 .write_command = sossi_write_command,
677 .read_data = sossi_read_data,
678 .write_data = sossi_write_data,
679 .transfer_area = sossi_transfer_area,
680
681 .max_transmit_size = SOSSI_MAX_XMIT_BYTES,
682};
683
684

source code of linux/drivers/video/fbdev/omap/sossi.c