1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2009 Nokia Corporation
4 * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
5 *
6 * Some code and ideas taken from drivers/video/omap/ driver
7 * by Imre Deak.
8 */
9
10#define DSS_SUBSYS_NAME "DPI"
11
12#include <linux/clk.h>
13#include <linux/delay.h>
14#include <linux/err.h>
15#include <linux/errno.h>
16#include <linux/export.h>
17#include <linux/kernel.h>
18#include <linux/of.h>
19#include <linux/platform_device.h>
20#include <linux/regulator/consumer.h>
21#include <linux/string.h>
22#include <linux/sys_soc.h>
23
24#include <drm/drm_bridge.h>
25
26#include "dss.h"
27#include "omapdss.h"
28
29struct dpi_data {
30	struct platform_device *pdev;
31	enum dss_model dss_model;
32	struct dss_device *dss;
33	unsigned int id;
34
35	struct regulator *vdds_dsi_reg;
36	enum dss_clk_source clk_src;
37	struct dss_pll *pll;
38
39	struct dss_lcd_mgr_config mgr_config;
40	unsigned long pixelclock;
41	int data_lines;
42
43	struct omap_dss_device output;
44	struct drm_bridge bridge;
45};
46
47#define drm_bridge_to_dpi(bridge) container_of(bridge, struct dpi_data, bridge)
48
49/* -----------------------------------------------------------------------------
50 * Clock Handling and PLL
51 */
52
53static enum dss_clk_source dpi_get_clk_src_dra7xx(struct dpi_data *dpi,
54						  enum omap_channel channel)
55{
56	/*
57	 * Possible clock sources:
58	 * LCD1: FCK/PLL1_1/HDMI_PLL
59	 * LCD2: FCK/PLL1_3/HDMI_PLL (DRA74x: PLL2_3)
60	 * LCD3: FCK/PLL1_3/HDMI_PLL (DRA74x: PLL2_1)
61	 */
62
63	switch (channel) {
64	case OMAP_DSS_CHANNEL_LCD:
65	{
66		if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL1_1))
67			return DSS_CLK_SRC_PLL1_1;
68		break;
69	}
70	case OMAP_DSS_CHANNEL_LCD2:
71	{
72		if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL1_3))
73			return DSS_CLK_SRC_PLL1_3;
74		if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL2_3))
75			return DSS_CLK_SRC_PLL2_3;
76		break;
77	}
78	case OMAP_DSS_CHANNEL_LCD3:
79	{
80		if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL2_1))
81			return DSS_CLK_SRC_PLL2_1;
82		if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL1_3))
83			return DSS_CLK_SRC_PLL1_3;
84		break;
85	}
86	default:
87		break;
88	}
89
90	return DSS_CLK_SRC_FCK;
91}
92
93static enum dss_clk_source dpi_get_clk_src(struct dpi_data *dpi)
94{
95	enum omap_channel channel = dpi->output.dispc_channel;
96
97	/*
98	 * XXX we can't currently use DSI PLL for DPI with OMAP3, as the DSI PLL
99	 * would also be used for DISPC fclk. Meaning, when the DPI output is
100	 * disabled, DISPC clock will be disabled, and TV out will stop.
101	 */
102	switch (dpi->dss_model) {
103	case DSS_MODEL_OMAP2:
104	case DSS_MODEL_OMAP3:
105		return DSS_CLK_SRC_FCK;
106
107	case DSS_MODEL_OMAP4:
108		switch (channel) {
109		case OMAP_DSS_CHANNEL_LCD:
110			return DSS_CLK_SRC_PLL1_1;
111		case OMAP_DSS_CHANNEL_LCD2:
112			return DSS_CLK_SRC_PLL2_1;
113		default:
114			return DSS_CLK_SRC_FCK;
115		}
116
117	case DSS_MODEL_OMAP5:
118		switch (channel) {
119		case OMAP_DSS_CHANNEL_LCD:
120			return DSS_CLK_SRC_PLL1_1;
121		case OMAP_DSS_CHANNEL_LCD3:
122			return DSS_CLK_SRC_PLL2_1;
123		case OMAP_DSS_CHANNEL_LCD2:
124		default:
125			return DSS_CLK_SRC_FCK;
126		}
127
128	case DSS_MODEL_DRA7:
129		return dpi_get_clk_src_dra7xx(dpi, channel);
130
131	default:
132		return DSS_CLK_SRC_FCK;
133	}
134}
135
136struct dpi_clk_calc_ctx {
137	struct dpi_data *dpi;
138	unsigned int clkout_idx;
139
140	/* inputs */
141
142	unsigned long pck_min, pck_max;
143
144	/* outputs */
145
146	struct dss_pll_clock_info pll_cinfo;
147	unsigned long fck;
148	struct dispc_clock_info dispc_cinfo;
149};
150
151static bool dpi_calc_dispc_cb(int lckd, int pckd, unsigned long lck,
152		unsigned long pck, void *data)
153{
154	struct dpi_clk_calc_ctx *ctx = data;
155
156	/*
157	 * Odd dividers give us uneven duty cycle, causing problem when level
158	 * shifted. So skip all odd dividers when the pixel clock is on the
159	 * higher side.
160	 */
161	if (ctx->pck_min >= 100000000) {
162		if (lckd > 1 && lckd % 2 != 0)
163			return false;
164
165		if (pckd > 1 && pckd % 2 != 0)
166			return false;
167	}
168
169	ctx->dispc_cinfo.lck_div = lckd;
170	ctx->dispc_cinfo.pck_div = pckd;
171	ctx->dispc_cinfo.lck = lck;
172	ctx->dispc_cinfo.pck = pck;
173
174	return true;
175}
176
177
178static bool dpi_calc_hsdiv_cb(int m_dispc, unsigned long dispc,
179		void *data)
180{
181	struct dpi_clk_calc_ctx *ctx = data;
182
183	ctx->pll_cinfo.mX[ctx->clkout_idx] = m_dispc;
184	ctx->pll_cinfo.clkout[ctx->clkout_idx] = dispc;
185
186	return dispc_div_calc(ctx->dpi->dss->dispc, dispc,
187			      ctx->pck_min, ctx->pck_max,
188			      dpi_calc_dispc_cb, ctx);
189}
190
191
192static bool dpi_calc_pll_cb(int n, int m, unsigned long fint,
193		unsigned long clkdco,
194		void *data)
195{
196	struct dpi_clk_calc_ctx *ctx = data;
197
198	ctx->pll_cinfo.n = n;
199	ctx->pll_cinfo.m = m;
200	ctx->pll_cinfo.fint = fint;
201	ctx->pll_cinfo.clkdco = clkdco;
202
203	return dss_pll_hsdiv_calc_a(ctx->dpi->pll, clkdco,
204		ctx->pck_min, dss_get_max_fck_rate(ctx->dpi->dss),
205		dpi_calc_hsdiv_cb, ctx);
206}
207
208static bool dpi_calc_dss_cb(unsigned long fck, void *data)
209{
210	struct dpi_clk_calc_ctx *ctx = data;
211
212	ctx->fck = fck;
213
214	return dispc_div_calc(ctx->dpi->dss->dispc, fck,
215			      ctx->pck_min, ctx->pck_max,
216			      dpi_calc_dispc_cb, ctx);
217}
218
219static bool dpi_pll_clk_calc(struct dpi_data *dpi, unsigned long pck,
220		struct dpi_clk_calc_ctx *ctx)
221{
222	unsigned long clkin;
223
224	memset(ctx, 0, sizeof(*ctx));
225	ctx->dpi = dpi;
226	ctx->clkout_idx = dss_pll_get_clkout_idx_for_src(dpi->clk_src);
227
228	clkin = clk_get_rate(dpi->pll->clkin);
229
230	if (dpi->pll->hw->type == DSS_PLL_TYPE_A) {
231		unsigned long pll_min, pll_max;
232
233		ctx->pck_min = pck - 1000;
234		ctx->pck_max = pck + 1000;
235
236		pll_min = 0;
237		pll_max = 0;
238
239		return dss_pll_calc_a(ctx->dpi->pll, clkin,
240				pll_min, pll_max,
241				dpi_calc_pll_cb, ctx);
242	} else { /* DSS_PLL_TYPE_B */
243		dss_pll_calc_b(dpi->pll, clkin, pck, &ctx->pll_cinfo);
244
245		ctx->dispc_cinfo.lck_div = 1;
246		ctx->dispc_cinfo.pck_div = 1;
247		ctx->dispc_cinfo.lck = ctx->pll_cinfo.clkout[0];
248		ctx->dispc_cinfo.pck = ctx->dispc_cinfo.lck;
249
250		return true;
251	}
252}
253
254static bool dpi_dss_clk_calc(struct dpi_data *dpi, unsigned long pck,
255			     struct dpi_clk_calc_ctx *ctx)
256{
257	int i;
258
259	/*
260	 * DSS fck gives us very few possibilities, so finding a good pixel
261	 * clock may not be possible. We try multiple times to find the clock,
262	 * each time widening the pixel clock range we look for, up to
263	 * +/- ~15MHz.
264	 */
265
266	for (i = 0; i < 25; ++i) {
267		bool ok;
268
269		memset(ctx, 0, sizeof(*ctx));
270		ctx->dpi = dpi;
271		if (pck > 1000 * i * i * i)
272			ctx->pck_min = max(pck - 1000 * i * i * i, 0lu);
273		else
274			ctx->pck_min = 0;
275		ctx->pck_max = pck + 1000 * i * i * i;
276
277		ok = dss_div_calc(dpi->dss, pck, ctx->pck_min,
278				  dpi_calc_dss_cb, ctx);
279		if (ok)
280			return ok;
281	}
282
283	return false;
284}
285
286
287
288static int dpi_set_pll_clk(struct dpi_data *dpi, unsigned long pck_req)
289{
290	struct dpi_clk_calc_ctx ctx;
291	int r;
292	bool ok;
293
294	ok = dpi_pll_clk_calc(dpi, pck_req, &ctx);
295	if (!ok)
296		return -EINVAL;
297
298	r = dss_pll_set_config(dpi->pll, &ctx.pll_cinfo);
299	if (r)
300		return r;
301
302	dss_select_lcd_clk_source(dpi->dss, dpi->output.dispc_channel,
303				  dpi->clk_src);
304
305	dpi->mgr_config.clock_info = ctx.dispc_cinfo;
306
307	return 0;
308}
309
310static int dpi_set_dispc_clk(struct dpi_data *dpi, unsigned long pck_req)
311{
312	struct dpi_clk_calc_ctx ctx;
313	int r;
314	bool ok;
315
316	ok = dpi_dss_clk_calc(dpi, pck_req, &ctx);
317	if (!ok)
318		return -EINVAL;
319
320	r = dss_set_fck_rate(dpi->dss, ctx.fck);
321	if (r)
322		return r;
323
324	dpi->mgr_config.clock_info = ctx.dispc_cinfo;
325
326	return 0;
327}
328
329static int dpi_set_mode(struct dpi_data *dpi)
330{
331	int r;
332
333	if (dpi->pll)
334		r = dpi_set_pll_clk(dpi, dpi->pixelclock);
335	else
336		r = dpi_set_dispc_clk(dpi, dpi->pixelclock);
337
338	return r;
339}
340
341static void dpi_config_lcd_manager(struct dpi_data *dpi)
342{
343	dpi->mgr_config.io_pad_mode = DSS_IO_PAD_MODE_BYPASS;
344
345	dpi->mgr_config.stallmode = false;
346	dpi->mgr_config.fifohandcheck = false;
347
348	dpi->mgr_config.video_port_width = dpi->data_lines;
349
350	dpi->mgr_config.lcden_sig_polarity = 0;
351
352	dss_mgr_set_lcd_config(&dpi->output, &dpi->mgr_config);
353}
354
355static int dpi_clock_update(struct dpi_data *dpi, unsigned long *clock)
356{
357	int lck_div, pck_div;
358	unsigned long fck;
359	struct dpi_clk_calc_ctx ctx;
360
361	if (dpi->pll) {
362		if (!dpi_pll_clk_calc(dpi, *clock, &ctx))
363			return -EINVAL;
364
365		fck = ctx.pll_cinfo.clkout[ctx.clkout_idx];
366	} else {
367		if (!dpi_dss_clk_calc(dpi, *clock, &ctx))
368			return -EINVAL;
369
370		fck = ctx.fck;
371	}
372
373	lck_div = ctx.dispc_cinfo.lck_div;
374	pck_div = ctx.dispc_cinfo.pck_div;
375
376	*clock = fck / lck_div / pck_div;
377
378	return 0;
379}
380
381static int dpi_verify_pll(struct dss_pll *pll)
382{
383	int r;
384
385	/* do initial setup with the PLL to see if it is operational */
386
387	r = dss_pll_enable(pll);
388	if (r)
389		return r;
390
391	dss_pll_disable(pll);
392
393	return 0;
394}
395
396static void dpi_init_pll(struct dpi_data *dpi)
397{
398	struct dss_pll *pll;
399
400	if (dpi->pll)
401		return;
402
403	dpi->clk_src = dpi_get_clk_src(dpi);
404
405	pll = dss_pll_find_by_src(dpi->dss, dpi->clk_src);
406	if (!pll)
407		return;
408
409	if (dpi_verify_pll(pll)) {
410		DSSWARN("PLL not operational\n");
411		return;
412	}
413
414	dpi->pll = pll;
415}
416
417/* -----------------------------------------------------------------------------
418 * DRM Bridge Operations
419 */
420
421static int dpi_bridge_attach(struct drm_bridge *bridge,
422			     enum drm_bridge_attach_flags flags)
423{
424	struct dpi_data *dpi = drm_bridge_to_dpi(bridge);
425
426	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR))
427		return -EINVAL;
428
429	dpi_init_pll(dpi);
430
431	return drm_bridge_attach(bridge->encoder, dpi->output.next_bridge,
432				 bridge, flags);
433}
434
435static enum drm_mode_status
436dpi_bridge_mode_valid(struct drm_bridge *bridge,
437		       const struct drm_display_info *info,
438		       const struct drm_display_mode *mode)
439{
440	struct dpi_data *dpi = drm_bridge_to_dpi(bridge);
441	unsigned long clock = mode->clock * 1000;
442	int ret;
443
444	if (mode->hdisplay % 8 != 0)
445		return MODE_BAD_WIDTH;
446
447	if (mode->clock == 0)
448		return MODE_NOCLOCK;
449
450	ret = dpi_clock_update(dpi, &clock);
451	if (ret < 0)
452		return MODE_CLOCK_RANGE;
453
454	return MODE_OK;
455}
456
457static bool dpi_bridge_mode_fixup(struct drm_bridge *bridge,
458				   const struct drm_display_mode *mode,
459				   struct drm_display_mode *adjusted_mode)
460{
461	struct dpi_data *dpi = drm_bridge_to_dpi(bridge);
462	unsigned long clock = mode->clock * 1000;
463	int ret;
464
465	ret = dpi_clock_update(dpi, &clock);
466	if (ret < 0)
467		return false;
468
469	adjusted_mode->clock = clock / 1000;
470
471	return true;
472}
473
474static void dpi_bridge_mode_set(struct drm_bridge *bridge,
475				 const struct drm_display_mode *mode,
476				 const struct drm_display_mode *adjusted_mode)
477{
478	struct dpi_data *dpi = drm_bridge_to_dpi(bridge);
479
480	dpi->pixelclock = adjusted_mode->clock * 1000;
481}
482
483static void dpi_bridge_enable(struct drm_bridge *bridge)
484{
485	struct dpi_data *dpi = drm_bridge_to_dpi(bridge);
486	int r;
487
488	if (dpi->vdds_dsi_reg) {
489		r = regulator_enable(dpi->vdds_dsi_reg);
490		if (r)
491			return;
492	}
493
494	r = dispc_runtime_get(dpi->dss->dispc);
495	if (r)
496		goto err_get_dispc;
497
498	r = dss_dpi_select_source(dpi->dss, dpi->id, dpi->output.dispc_channel);
499	if (r)
500		goto err_src_sel;
501
502	if (dpi->pll) {
503		r = dss_pll_enable(dpi->pll);
504		if (r)
505			goto err_pll_init;
506	}
507
508	r = dpi_set_mode(dpi);
509	if (r)
510		goto err_set_mode;
511
512	dpi_config_lcd_manager(dpi);
513
514	mdelay(2);
515
516	r = dss_mgr_enable(&dpi->output);
517	if (r)
518		goto err_mgr_enable;
519
520	return;
521
522err_mgr_enable:
523err_set_mode:
524	if (dpi->pll)
525		dss_pll_disable(dpi->pll);
526err_pll_init:
527err_src_sel:
528	dispc_runtime_put(dpi->dss->dispc);
529err_get_dispc:
530	if (dpi->vdds_dsi_reg)
531		regulator_disable(dpi->vdds_dsi_reg);
532}
533
534static void dpi_bridge_disable(struct drm_bridge *bridge)
535{
536	struct dpi_data *dpi = drm_bridge_to_dpi(bridge);
537
538	dss_mgr_disable(&dpi->output);
539
540	if (dpi->pll) {
541		dss_select_lcd_clk_source(dpi->dss, dpi->output.dispc_channel,
542					  DSS_CLK_SRC_FCK);
543		dss_pll_disable(dpi->pll);
544	}
545
546	dispc_runtime_put(dpi->dss->dispc);
547
548	if (dpi->vdds_dsi_reg)
549		regulator_disable(dpi->vdds_dsi_reg);
550}
551
552static const struct drm_bridge_funcs dpi_bridge_funcs = {
553	.attach = dpi_bridge_attach,
554	.mode_valid = dpi_bridge_mode_valid,
555	.mode_fixup = dpi_bridge_mode_fixup,
556	.mode_set = dpi_bridge_mode_set,
557	.enable = dpi_bridge_enable,
558	.disable = dpi_bridge_disable,
559};
560
561static void dpi_bridge_init(struct dpi_data *dpi)
562{
563	dpi->bridge.funcs = &dpi_bridge_funcs;
564	dpi->bridge.of_node = dpi->pdev->dev.of_node;
565	dpi->bridge.type = DRM_MODE_CONNECTOR_DPI;
566
567	drm_bridge_add(&dpi->bridge);
568}
569
570static void dpi_bridge_cleanup(struct dpi_data *dpi)
571{
572	drm_bridge_remove(&dpi->bridge);
573}
574
575/* -----------------------------------------------------------------------------
576 * Initialisation and Cleanup
577 */
578
579/*
580 * Return a hardcoded channel for the DPI output. This should work for
581 * current use cases, but this can be later expanded to either resolve
582 * the channel in some more dynamic manner, or get the channel as a user
583 * parameter.
584 */
585static enum omap_channel dpi_get_channel(struct dpi_data *dpi)
586{
587	switch (dpi->dss_model) {
588	case DSS_MODEL_OMAP2:
589	case DSS_MODEL_OMAP3:
590		return OMAP_DSS_CHANNEL_LCD;
591
592	case DSS_MODEL_DRA7:
593		switch (dpi->id) {
594		case 2:
595			return OMAP_DSS_CHANNEL_LCD3;
596		case 1:
597			return OMAP_DSS_CHANNEL_LCD2;
598		case 0:
599		default:
600			return OMAP_DSS_CHANNEL_LCD;
601		}
602
603	case DSS_MODEL_OMAP4:
604		return OMAP_DSS_CHANNEL_LCD2;
605
606	case DSS_MODEL_OMAP5:
607		return OMAP_DSS_CHANNEL_LCD3;
608
609	default:
610		DSSWARN("unsupported DSS version\n");
611		return OMAP_DSS_CHANNEL_LCD;
612	}
613}
614
615static int dpi_init_output_port(struct dpi_data *dpi, struct device_node *port)
616{
617	struct omap_dss_device *out = &dpi->output;
618	u32 port_num = 0;
619	int r;
620
621	dpi_bridge_init(dpi);
622
623	of_property_read_u32(port, "reg", &port_num);
624	dpi->id = port_num <= 2 ? port_num : 0;
625
626	switch (port_num) {
627	case 2:
628		out->name = "dpi.2";
629		break;
630	case 1:
631		out->name = "dpi.1";
632		break;
633	case 0:
634	default:
635		out->name = "dpi.0";
636		break;
637	}
638
639	out->dev = &dpi->pdev->dev;
640	out->id = OMAP_DSS_OUTPUT_DPI;
641	out->type = OMAP_DISPLAY_TYPE_DPI;
642	out->dispc_channel = dpi_get_channel(dpi);
643	out->of_port = port_num;
644
645	r = omapdss_device_init_output(out, &dpi->bridge);
646	if (r < 0) {
647		dpi_bridge_cleanup(dpi);
648		return r;
649	}
650
651	omapdss_device_register(out);
652
653	return 0;
654}
655
656static void dpi_uninit_output_port(struct device_node *port)
657{
658	struct dpi_data *dpi = port->data;
659	struct omap_dss_device *out = &dpi->output;
660
661	omapdss_device_unregister(out);
662	omapdss_device_cleanup_output(out);
663
664	dpi_bridge_cleanup(dpi);
665}
666
667/* -----------------------------------------------------------------------------
668 * Initialisation and Cleanup
669 */
670
671static const struct soc_device_attribute dpi_soc_devices[] = {
672	{ .machine = "OMAP3[456]*" },
673	{ .machine = "[AD]M37*" },
674	{ /* sentinel */ }
675};
676
677static int dpi_init_regulator(struct dpi_data *dpi)
678{
679	struct regulator *vdds_dsi;
680
681	/*
682	 * The DPI uses the DSI VDDS on OMAP34xx, OMAP35xx, OMAP36xx, AM37xx and
683	 * DM37xx only.
684	 */
685	if (!soc_device_match(dpi_soc_devices))
686		return 0;
687
688	vdds_dsi = devm_regulator_get(&dpi->pdev->dev, "vdds_dsi");
689	if (IS_ERR(vdds_dsi)) {
690		if (PTR_ERR(vdds_dsi) != -EPROBE_DEFER)
691			DSSERR("can't get VDDS_DSI regulator\n");
692		return PTR_ERR(vdds_dsi);
693	}
694
695	dpi->vdds_dsi_reg = vdds_dsi;
696
697	return 0;
698}
699
700int dpi_init_port(struct dss_device *dss, struct platform_device *pdev,
701		  struct device_node *port, enum dss_model dss_model)
702{
703	struct dpi_data *dpi;
704	struct device_node *ep;
705	u32 datalines;
706	int r;
707
708	dpi = devm_kzalloc(&pdev->dev, sizeof(*dpi), GFP_KERNEL);
709	if (!dpi)
710		return -ENOMEM;
711
712	ep = of_get_next_child(port, NULL);
713	if (!ep)
714		return 0;
715
716	r = of_property_read_u32(ep, "data-lines", &datalines);
717	of_node_put(ep);
718	if (r) {
719		DSSERR("failed to parse datalines\n");
720		return r;
721	}
722
723	dpi->data_lines = datalines;
724
725	dpi->pdev = pdev;
726	dpi->dss_model = dss_model;
727	dpi->dss = dss;
728	port->data = dpi;
729
730	r = dpi_init_regulator(dpi);
731	if (r)
732		return r;
733
734	return dpi_init_output_port(dpi, port);
735}
736
737void dpi_uninit_port(struct device_node *port)
738{
739	struct dpi_data *dpi = port->data;
740
741	if (!dpi)
742		return;
743
744	dpi_uninit_output_port(port);
745}
746