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  1/*
  2 * i.MX drm driver - LVDS display bridge
  3 *
  4 * Copyright (C) 2012 Sascha Hauer, Pengutronix
  5 *
  6 * This program is free software; you can redistribute it and/or
  7 * modify it under the terms of the GNU General Public License
  8 * as published by the Free Software Foundation; either version 2
  9 * of the License, or (at your option) any later version.
 10 * This program is distributed in the hope that it will be useful,
 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13 * GNU General Public License for more details.
 14 */
 15
 16#include <linux/module.h>
 17#include <linux/clk.h>
 18#include <linux/component.h>
 19#include <drm/drmP.h>
 20#include <drm/drm_atomic.h>
 21#include <drm/drm_atomic_helper.h>
 22#include <drm/drm_fb_helper.h>
 23#include <drm/drm_crtc_helper.h>
 24#include <drm/drm_of.h>
 25#include <drm/drm_panel.h>
 26#include <linux/mfd/syscon.h>
 27#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
 28#include <linux/of_device.h>
 29#include <linux/of_graph.h>
 30#include <video/of_display_timing.h>
 31#include <video/of_videomode.h>
 32#include <linux/regmap.h>
 33#include <linux/videodev2.h>
 34
 35#include "imx-drm.h"
 36
 37#define DRIVER_NAME "imx-ldb"
 38
 39#define LDB_CH0_MODE_EN_TO_DI0		(1 << 0)
 40#define LDB_CH0_MODE_EN_TO_DI1		(3 << 0)
 41#define LDB_CH0_MODE_EN_MASK		(3 << 0)
 42#define LDB_CH1_MODE_EN_TO_DI0		(1 << 2)
 43#define LDB_CH1_MODE_EN_TO_DI1		(3 << 2)
 44#define LDB_CH1_MODE_EN_MASK		(3 << 2)
 45#define LDB_SPLIT_MODE_EN		(1 << 4)
 46#define LDB_DATA_WIDTH_CH0_24		(1 << 5)
 47#define LDB_BIT_MAP_CH0_JEIDA		(1 << 6)
 48#define LDB_DATA_WIDTH_CH1_24		(1 << 7)
 49#define LDB_BIT_MAP_CH1_JEIDA		(1 << 8)
 50#define LDB_DI0_VS_POL_ACT_LOW		(1 << 9)
 51#define LDB_DI1_VS_POL_ACT_LOW		(1 << 10)
 52#define LDB_BGREF_RMODE_INT		(1 << 15)
 53
 54struct imx_ldb;
 55
 56struct imx_ldb_channel {
 57	struct imx_ldb *ldb;
 58	struct drm_connector connector;
 59	struct drm_encoder encoder;
 60
 61	/* Defines what is connected to the ldb, only one at a time */
 62	struct drm_panel *panel;
 63	struct drm_bridge *bridge;
 64
 65	struct device_node *child;
 66	struct i2c_adapter *ddc;
 67	int chno;
 68	void *edid;
 69	int edid_len;
 70	struct drm_display_mode mode;
 71	int mode_valid;
 72	u32 bus_format;
 73	u32 bus_flags;
 74};
 75
 76static inline struct imx_ldb_channel *con_to_imx_ldb_ch(struct drm_connector *c)
 77{
 78	return container_of(c, struct imx_ldb_channel, connector);
 79}
 80
 81static inline struct imx_ldb_channel *enc_to_imx_ldb_ch(struct drm_encoder *e)
 82{
 83	return container_of(e, struct imx_ldb_channel, encoder);
 84}
 85
 86struct bus_mux {
 87	int reg;
 88	int shift;
 89	int mask;
 90};
 91
 92struct imx_ldb {
 93	struct regmap *regmap;
 94	struct device *dev;
 95	struct imx_ldb_channel channel[2];
 96	struct clk *clk[2]; /* our own clock */
 97	struct clk *clk_sel[4]; /* parent of display clock */
 98	struct clk *clk_parent[4]; /* original parent of clk_sel */
 99	struct clk *clk_pll[2]; /* upstream clock we can adjust */
100	u32 ldb_ctrl;
101	const struct bus_mux *lvds_mux;
102};
103
104static void imx_ldb_ch_set_bus_format(struct imx_ldb_channel *imx_ldb_ch,
105				      u32 bus_format)
106{
107	struct imx_ldb *ldb = imx_ldb_ch->ldb;
108	int dual = ldb->ldb_ctrl & LDB_SPLIT_MODE_EN;
109
110	switch (bus_format) {
111	case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
112		break;
113	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
114		if (imx_ldb_ch->chno == 0 || dual)
115			ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH0_24;
116		if (imx_ldb_ch->chno == 1 || dual)
117			ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH1_24;
118		break;
119	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
120		if (imx_ldb_ch->chno == 0 || dual)
121			ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH0_24 |
122					 LDB_BIT_MAP_CH0_JEIDA;
123		if (imx_ldb_ch->chno == 1 || dual)
124			ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH1_24 |
125					 LDB_BIT_MAP_CH1_JEIDA;
126		break;
127	}
128}
129
130static int imx_ldb_connector_get_modes(struct drm_connector *connector)
131{
132	struct imx_ldb_channel *imx_ldb_ch = con_to_imx_ldb_ch(connector);
133	int num_modes = 0;
134
135	if (imx_ldb_ch->panel && imx_ldb_ch->panel->funcs &&
136	    imx_ldb_ch->panel->funcs->get_modes) {
137		num_modes = imx_ldb_ch->panel->funcs->get_modes(imx_ldb_ch->panel);
138		if (num_modes > 0)
139			return num_modes;
140	}
141
142	if (!imx_ldb_ch->edid && imx_ldb_ch->ddc)
143		imx_ldb_ch->edid = drm_get_edid(connector, imx_ldb_ch->ddc);
144
145	if (imx_ldb_ch->edid) {
146		drm_mode_connector_update_edid_property(connector,
147							imx_ldb_ch->edid);
148		num_modes = drm_add_edid_modes(connector, imx_ldb_ch->edid);
149	}
150
151	if (imx_ldb_ch->mode_valid) {
152		struct drm_display_mode *mode;
153
154		mode = drm_mode_create(connector->dev);
155		if (!mode)
156			return -EINVAL;
157		drm_mode_copy(mode, &imx_ldb_ch->mode);
158		mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
159		drm_mode_probed_add(connector, mode);
160		num_modes++;
161	}
162
163	return num_modes;
164}
165
166static struct drm_encoder *imx_ldb_connector_best_encoder(
167		struct drm_connector *connector)
168{
169	struct imx_ldb_channel *imx_ldb_ch = con_to_imx_ldb_ch(connector);
170
171	return &imx_ldb_ch->encoder;
172}
173
174static void imx_ldb_set_clock(struct imx_ldb *ldb, int mux, int chno,
175		unsigned long serial_clk, unsigned long di_clk)
176{
177	int ret;
178
179	dev_dbg(ldb->dev, "%s: now: %ld want: %ld\n", __func__,
180			clk_get_rate(ldb->clk_pll[chno]), serial_clk);
181	clk_set_rate(ldb->clk_pll[chno], serial_clk);
182
183	dev_dbg(ldb->dev, "%s after: %ld\n", __func__,
184			clk_get_rate(ldb->clk_pll[chno]));
185
186	dev_dbg(ldb->dev, "%s: now: %ld want: %ld\n", __func__,
187			clk_get_rate(ldb->clk[chno]),
188			(long int)di_clk);
189	clk_set_rate(ldb->clk[chno], di_clk);
190
191	dev_dbg(ldb->dev, "%s after: %ld\n", __func__,
192			clk_get_rate(ldb->clk[chno]));
193
194	/* set display clock mux to LDB input clock */
195	ret = clk_set_parent(ldb->clk_sel[mux], ldb->clk[chno]);
196	if (ret)
197		dev_err(ldb->dev,
198			"unable to set di%d parent clock to ldb_di%d\n", mux,
199			chno);
200}
201
202static void imx_ldb_encoder_enable(struct drm_encoder *encoder)
203{
204	struct imx_ldb_channel *imx_ldb_ch = enc_to_imx_ldb_ch(encoder);
205	struct imx_ldb *ldb = imx_ldb_ch->ldb;
206	int dual = ldb->ldb_ctrl & LDB_SPLIT_MODE_EN;
207	int mux = drm_of_encoder_active_port_id(imx_ldb_ch->child, encoder);
208
209	drm_panel_prepare(imx_ldb_ch->panel);
210
211	if (dual) {
212		clk_set_parent(ldb->clk_sel[mux], ldb->clk[0]);
213		clk_set_parent(ldb->clk_sel[mux], ldb->clk[1]);
214
215		clk_prepare_enable(ldb->clk[0]);
216		clk_prepare_enable(ldb->clk[1]);
217	} else {
218		clk_set_parent(ldb->clk_sel[mux], ldb->clk[imx_ldb_ch->chno]);
219	}
220
221	if (imx_ldb_ch == &ldb->channel[0] || dual) {
222		ldb->ldb_ctrl &= ~LDB_CH0_MODE_EN_MASK;
223		if (mux == 0 || ldb->lvds_mux)
224			ldb->ldb_ctrl |= LDB_CH0_MODE_EN_TO_DI0;
225		else if (mux == 1)
226			ldb->ldb_ctrl |= LDB_CH0_MODE_EN_TO_DI1;
227	}
228	if (imx_ldb_ch == &ldb->channel[1] || dual) {
229		ldb->ldb_ctrl &= ~LDB_CH1_MODE_EN_MASK;
230		if (mux == 1 || ldb->lvds_mux)
231			ldb->ldb_ctrl |= LDB_CH1_MODE_EN_TO_DI1;
232		else if (mux == 0)
233			ldb->ldb_ctrl |= LDB_CH1_MODE_EN_TO_DI0;
234	}
235
236	if (ldb->lvds_mux) {
237		const struct bus_mux *lvds_mux = NULL;
238
239		if (imx_ldb_ch == &ldb->channel[0])
240			lvds_mux = &ldb->lvds_mux[0];
241		else if (imx_ldb_ch == &ldb->channel[1])
242			lvds_mux = &ldb->lvds_mux[1];
243
244		regmap_update_bits(ldb->regmap, lvds_mux->reg, lvds_mux->mask,
245				   mux << lvds_mux->shift);
246	}
247
248	regmap_write(ldb->regmap, IOMUXC_GPR2, ldb->ldb_ctrl);
249
250	drm_panel_enable(imx_ldb_ch->panel);
251}
252
253static void
254imx_ldb_encoder_atomic_mode_set(struct drm_encoder *encoder,
255				struct drm_crtc_state *crtc_state,
256				struct drm_connector_state *connector_state)
257{
258	struct imx_ldb_channel *imx_ldb_ch = enc_to_imx_ldb_ch(encoder);
259	struct drm_display_mode *mode = &crtc_state->adjusted_mode;
260	struct imx_ldb *ldb = imx_ldb_ch->ldb;
261	int dual = ldb->ldb_ctrl & LDB_SPLIT_MODE_EN;
262	unsigned long serial_clk;
263	unsigned long di_clk = mode->clock * 1000;
264	int mux = drm_of_encoder_active_port_id(imx_ldb_ch->child, encoder);
265	u32 bus_format = imx_ldb_ch->bus_format;
266
267	if (mode->clock > 170000) {
268		dev_warn(ldb->dev,
269			 "%s: mode exceeds 170 MHz pixel clock\n", __func__);
270	}
271	if (mode->clock > 85000 && !dual) {
272		dev_warn(ldb->dev,
273			 "%s: mode exceeds 85 MHz pixel clock\n", __func__);
274	}
275
276	if (dual) {
277		serial_clk = 3500UL * mode->clock;
278		imx_ldb_set_clock(ldb, mux, 0, serial_clk, di_clk);
279		imx_ldb_set_clock(ldb, mux, 1, serial_clk, di_clk);
280	} else {
281		serial_clk = 7000UL * mode->clock;
282		imx_ldb_set_clock(ldb, mux, imx_ldb_ch->chno, serial_clk,
283				  di_clk);
284	}
285
286	/* FIXME - assumes straight connections DI0 --> CH0, DI1 --> CH1 */
287	if (imx_ldb_ch == &ldb->channel[0] || dual) {
288		if (mode->flags & DRM_MODE_FLAG_NVSYNC)
289			ldb->ldb_ctrl |= LDB_DI0_VS_POL_ACT_LOW;
290		else if (mode->flags & DRM_MODE_FLAG_PVSYNC)
291			ldb->ldb_ctrl &= ~LDB_DI0_VS_POL_ACT_LOW;
292	}
293	if (imx_ldb_ch == &ldb->channel[1] || dual) {
294		if (mode->flags & DRM_MODE_FLAG_NVSYNC)
295			ldb->ldb_ctrl |= LDB_DI1_VS_POL_ACT_LOW;
296		else if (mode->flags & DRM_MODE_FLAG_PVSYNC)
297			ldb->ldb_ctrl &= ~LDB_DI1_VS_POL_ACT_LOW;
298	}
299
300	if (!bus_format) {
301		struct drm_connector *connector = connector_state->connector;
302		struct drm_display_info *di = &connector->display_info;
303
304		if (di->num_bus_formats)
305			bus_format = di->bus_formats[0];
306	}
307	imx_ldb_ch_set_bus_format(imx_ldb_ch, bus_format);
308}
309
310static void imx_ldb_encoder_disable(struct drm_encoder *encoder)
311{
312	struct imx_ldb_channel *imx_ldb_ch = enc_to_imx_ldb_ch(encoder);
313	struct imx_ldb *ldb = imx_ldb_ch->ldb;
314	int mux, ret;
315
316	drm_panel_disable(imx_ldb_ch->panel);
317
318	if (imx_ldb_ch == &ldb->channel[0])
319		ldb->ldb_ctrl &= ~LDB_CH0_MODE_EN_MASK;
320	else if (imx_ldb_ch == &ldb->channel[1])
321		ldb->ldb_ctrl &= ~LDB_CH1_MODE_EN_MASK;
322
323	regmap_write(ldb->regmap, IOMUXC_GPR2, ldb->ldb_ctrl);
324
325	if (ldb->ldb_ctrl & LDB_SPLIT_MODE_EN) {
326		clk_disable_unprepare(ldb->clk[0]);
327		clk_disable_unprepare(ldb->clk[1]);
328	}
329
330	if (ldb->lvds_mux) {
331		const struct bus_mux *lvds_mux = NULL;
332
333		if (imx_ldb_ch == &ldb->channel[0])
334			lvds_mux = &ldb->lvds_mux[0];
335		else if (imx_ldb_ch == &ldb->channel[1])
336			lvds_mux = &ldb->lvds_mux[1];
337
338		regmap_read(ldb->regmap, lvds_mux->reg, &mux);
339		mux &= lvds_mux->mask;
340		mux >>= lvds_mux->shift;
341	} else {
342		mux = (imx_ldb_ch == &ldb->channel[0]) ? 0 : 1;
343	}
344
345	/* set display clock mux back to original input clock */
346	ret = clk_set_parent(ldb->clk_sel[mux], ldb->clk_parent[mux]);
347	if (ret)
348		dev_err(ldb->dev,
349			"unable to set di%d parent clock to original parent\n",
350			mux);
351
352	drm_panel_unprepare(imx_ldb_ch->panel);
353}
354
355static int imx_ldb_encoder_atomic_check(struct drm_encoder *encoder,
356					struct drm_crtc_state *crtc_state,
357					struct drm_connector_state *conn_state)
358{
359	struct imx_crtc_state *imx_crtc_state = to_imx_crtc_state(crtc_state);
360	struct imx_ldb_channel *imx_ldb_ch = enc_to_imx_ldb_ch(encoder);
361	struct drm_display_info *di = &conn_state->connector->display_info;
362	u32 bus_format = imx_ldb_ch->bus_format;
363
364	/* Bus format description in DT overrides connector display info. */
365	if (!bus_format && di->num_bus_formats) {
366		bus_format = di->bus_formats[0];
367		imx_crtc_state->bus_flags = di->bus_flags;
368	} else {
369		bus_format = imx_ldb_ch->bus_format;
370		imx_crtc_state->bus_flags = imx_ldb_ch->bus_flags;
371	}
372	switch (bus_format) {
373	case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
374		imx_crtc_state->bus_format = MEDIA_BUS_FMT_RGB666_1X18;
375		break;
376	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
377	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
378		imx_crtc_state->bus_format = MEDIA_BUS_FMT_RGB888_1X24;
379		break;
380	default:
381		return -EINVAL;
382	}
383
384	imx_crtc_state->di_hsync_pin = 2;
385	imx_crtc_state->di_vsync_pin = 3;
386
387	return 0;
388}
389
390
391static const struct drm_connector_funcs imx_ldb_connector_funcs = {
392	.dpms = drm_atomic_helper_connector_dpms,
393	.fill_modes = drm_helper_probe_single_connector_modes,
394	.destroy = imx_drm_connector_destroy,
395	.reset = drm_atomic_helper_connector_reset,
396	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
397	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
398};
399
400static const struct drm_connector_helper_funcs imx_ldb_connector_helper_funcs = {
401	.get_modes = imx_ldb_connector_get_modes,
402	.best_encoder = imx_ldb_connector_best_encoder,
403};
404
405static const struct drm_encoder_funcs imx_ldb_encoder_funcs = {
406	.destroy = imx_drm_encoder_destroy,
407};
408
409static const struct drm_encoder_helper_funcs imx_ldb_encoder_helper_funcs = {
410	.atomic_mode_set = imx_ldb_encoder_atomic_mode_set,
411	.enable = imx_ldb_encoder_enable,
412	.disable = imx_ldb_encoder_disable,
413	.atomic_check = imx_ldb_encoder_atomic_check,
414};
415
416static int imx_ldb_get_clk(struct imx_ldb *ldb, int chno)
417{
418	char clkname[16];
419
420	snprintf(clkname, sizeof(clkname), "di%d", chno);
421	ldb->clk[chno] = devm_clk_get(ldb->dev, clkname);
422	if (IS_ERR(ldb->clk[chno]))
423		return PTR_ERR(ldb->clk[chno]);
424
425	snprintf(clkname, sizeof(clkname), "di%d_pll", chno);
426	ldb->clk_pll[chno] = devm_clk_get(ldb->dev, clkname);
427
428	return PTR_ERR_OR_ZERO(ldb->clk_pll[chno]);
429}
430
431static int imx_ldb_register(struct drm_device *drm,
432	struct imx_ldb_channel *imx_ldb_ch)
433{
434	struct imx_ldb *ldb = imx_ldb_ch->ldb;
435	struct drm_encoder *encoder = &imx_ldb_ch->encoder;
436	int ret;
437
438	ret = imx_drm_encoder_parse_of(drm, encoder, imx_ldb_ch->child);
439	if (ret)
440		return ret;
441
442	ret = imx_ldb_get_clk(ldb, imx_ldb_ch->chno);
443	if (ret)
444		return ret;
445
446	if (ldb->ldb_ctrl & LDB_SPLIT_MODE_EN) {
447		ret = imx_ldb_get_clk(ldb, 1);
448		if (ret)
449			return ret;
450	}
451
452	drm_encoder_helper_add(encoder, &imx_ldb_encoder_helper_funcs);
453	drm_encoder_init(drm, encoder, &imx_ldb_encoder_funcs,
454			 DRM_MODE_ENCODER_LVDS, NULL);
455
456	if (imx_ldb_ch->bridge) {
457		imx_ldb_ch->bridge->encoder = encoder;
458
459		imx_ldb_ch->encoder.bridge = imx_ldb_ch->bridge;
460		ret = drm_bridge_attach(drm, imx_ldb_ch->bridge);
461		if (ret) {
462			DRM_ERROR("Failed to initialize bridge with drm\n");
463			return ret;
464		}
465	} else {
466		/*
467		 * We want to add the connector whenever there is no bridge
468		 * that brings its own, not only when there is a panel. For
469		 * historical reasons, the ldb driver can also work without
470		 * a panel.
471		 */
472		drm_connector_helper_add(&imx_ldb_ch->connector,
473				&imx_ldb_connector_helper_funcs);
474		drm_connector_init(drm, &imx_ldb_ch->connector,
475				&imx_ldb_connector_funcs,
476				DRM_MODE_CONNECTOR_LVDS);
477		drm_mode_connector_attach_encoder(&imx_ldb_ch->connector,
478				encoder);
479	}
480
481	if (imx_ldb_ch->panel) {
482		ret = drm_panel_attach(imx_ldb_ch->panel,
483				       &imx_ldb_ch->connector);
484		if (ret)
485			return ret;
486	}
487
488	return 0;
489}
490
491enum {
492	LVDS_BIT_MAP_SPWG,
493	LVDS_BIT_MAP_JEIDA
494};
495
496struct imx_ldb_bit_mapping {
497	u32 bus_format;
498	u32 datawidth;
499	const char * const mapping;
500};
501
502static const struct imx_ldb_bit_mapping imx_ldb_bit_mappings[] = {
503	{ MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,  18, "spwg" },
504	{ MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,  24, "spwg" },
505	{ MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA, 24, "jeida" },
506};
507
508static u32 of_get_bus_format(struct device *dev, struct device_node *np)
509{
510	const char *bm;
511	u32 datawidth = 0;
512	int ret, i;
513
514	ret = of_property_read_string(np, "fsl,data-mapping", &bm);
515	if (ret < 0)
516		return ret;
517
518	of_property_read_u32(np, "fsl,data-width", &datawidth);
519
520	for (i = 0; i < ARRAY_SIZE(imx_ldb_bit_mappings); i++) {
521		if (!strcasecmp(bm, imx_ldb_bit_mappings[i].mapping) &&
522		    datawidth == imx_ldb_bit_mappings[i].datawidth)
523			return imx_ldb_bit_mappings[i].bus_format;
524	}
525
526	dev_err(dev, "invalid data mapping: %d-bit \"%s\"\n", datawidth, bm);
527
528	return -ENOENT;
529}
530
531static struct bus_mux imx6q_lvds_mux[2] = {
532	{
533		.reg = IOMUXC_GPR3,
534		.shift = 6,
535		.mask = IMX6Q_GPR3_LVDS0_MUX_CTL_MASK,
536	}, {
537		.reg = IOMUXC_GPR3,
538		.shift = 8,
539		.mask = IMX6Q_GPR3_LVDS1_MUX_CTL_MASK,
540	}
541};
542
543/*
544 * For a device declaring compatible = "fsl,imx6q-ldb", "fsl,imx53-ldb",
545 * of_match_device will walk through this list and take the first entry
546 * matching any of its compatible values. Therefore, the more generic
547 * entries (in this case fsl,imx53-ldb) need to be ordered last.
548 */
549static const struct of_device_id imx_ldb_dt_ids[] = {
550	{ .compatible = "fsl,imx6q-ldb", .data = imx6q_lvds_mux, },
551	{ .compatible = "fsl,imx53-ldb", .data = NULL, },
552	{ }
553};
554MODULE_DEVICE_TABLE(of, imx_ldb_dt_ids);
555
556static int imx_ldb_panel_ddc(struct device *dev,
557		struct imx_ldb_channel *channel, struct device_node *child)
558{
559	struct device_node *ddc_node;
560	const u8 *edidp;
561	int ret;
562
563	ddc_node = of_parse_phandle(child, "ddc-i2c-bus", 0);
564	if (ddc_node) {
565		channel->ddc = of_find_i2c_adapter_by_node(ddc_node);
566		of_node_put(ddc_node);
567		if (!channel->ddc) {
568			dev_warn(dev, "failed to get ddc i2c adapter\n");
569			return -EPROBE_DEFER;
570		}
571	}
572
573	if (!channel->ddc) {
574		/* if no DDC available, fallback to hardcoded EDID */
575		dev_dbg(dev, "no ddc available\n");
576
577		edidp = of_get_property(child, "edid",
578					&channel->edid_len);
579		if (edidp) {
580			channel->edid = kmemdup(edidp,
581						channel->edid_len,
582						GFP_KERNEL);
583		} else if (!channel->panel) {
584			/* fallback to display-timings node */
585			ret = of_get_drm_display_mode(child,
586						      &channel->mode,
587						      &channel->bus_flags,
588						      OF_USE_NATIVE_MODE);
589			if (!ret)
590				channel->mode_valid = 1;
591		}
592	}
593	return 0;
594}
595
596static int imx_ldb_bind(struct device *dev, struct device *master, void *data)
597{
598	struct drm_device *drm = data;
599	struct device_node *np = dev->of_node;
600	const struct of_device_id *of_id =
601			of_match_device(imx_ldb_dt_ids, dev);
602	struct device_node *child;
603	struct imx_ldb *imx_ldb;
604	int dual;
605	int ret;
606	int i;
607
608	imx_ldb = devm_kzalloc(dev, sizeof(*imx_ldb), GFP_KERNEL);
609	if (!imx_ldb)
610		return -ENOMEM;
611
612	imx_ldb->regmap = syscon_regmap_lookup_by_phandle(np, "gpr");
613	if (IS_ERR(imx_ldb->regmap)) {
614		dev_err(dev, "failed to get parent regmap\n");
615		return PTR_ERR(imx_ldb->regmap);
616	}
617
618	imx_ldb->dev = dev;
619
620	if (of_id)
621		imx_ldb->lvds_mux = of_id->data;
622
623	dual = of_property_read_bool(np, "fsl,dual-channel");
624	if (dual)
625		imx_ldb->ldb_ctrl |= LDB_SPLIT_MODE_EN;
626
627	/*
628	 * There are three different possible clock mux configurations:
629	 * i.MX53:  ipu1_di0_sel, ipu1_di1_sel
630	 * i.MX6q:  ipu1_di0_sel, ipu1_di1_sel, ipu2_di0_sel, ipu2_di1_sel
631	 * i.MX6dl: ipu1_di0_sel, ipu1_di1_sel, lcdif_sel
632	 * Map them all to di0_sel...di3_sel.
633	 */
634	for (i = 0; i < 4; i++) {
635		char clkname[16];
636
637		sprintf(clkname, "di%d_sel", i);
638		imx_ldb->clk_sel[i] = devm_clk_get(imx_ldb->dev, clkname);
639		if (IS_ERR(imx_ldb->clk_sel[i])) {
640			ret = PTR_ERR(imx_ldb->clk_sel[i]);
641			imx_ldb->clk_sel[i] = NULL;
642			break;
643		}
644
645		imx_ldb->clk_parent[i] = clk_get_parent(imx_ldb->clk_sel[i]);
646	}
647	if (i == 0)
648		return ret;
649
650	for_each_child_of_node(np, child) {
651		struct imx_ldb_channel *channel;
652		struct device_node *ep;
653		int bus_format;
654
655		ret = of_property_read_u32(child, "reg", &i);
656		if (ret || i < 0 || i > 1)
657			return -EINVAL;
658
659		if (dual && i > 0) {
660			dev_warn(dev, "dual-channel mode, ignoring second output\n");
661			continue;
662		}
663
664		if (!of_device_is_available(child))
665			continue;
666
667		channel = &imx_ldb->channel[i];
668		channel->ldb = imx_ldb;
669		channel->chno = i;
670		channel->child = child;
671
672		/*
673		 * The output port is port@4 with an external 4-port mux or
674		 * port@2 with the internal 2-port mux.
675		 */
676		ep = of_graph_get_endpoint_by_regs(child,
677						   imx_ldb->lvds_mux ? 4 : 2,
678						   -1);
679		if (ep) {
680			struct device_node *remote;
681
682			remote = of_graph_get_remote_port_parent(ep);
683			of_node_put(ep);
684			if (remote) {
685				channel->panel = of_drm_find_panel(remote);
686				channel->bridge = of_drm_find_bridge(remote);
687			} else
688				return -EPROBE_DEFER;
689			of_node_put(remote);
690
691			if (!channel->panel && !channel->bridge) {
692				dev_err(dev, "panel/bridge not found: %s\n",
693					remote->full_name);
694				return -EPROBE_DEFER;
695			}
696		}
697
698		/* panel ddc only if there is no bridge */
699		if (!channel->bridge) {
700			ret = imx_ldb_panel_ddc(dev, channel, child);
701			if (ret)
702				return ret;
703		}
704
705		bus_format = of_get_bus_format(dev, child);
706		if (bus_format == -EINVAL) {
707			/*
708			 * If no bus format was specified in the device tree,
709			 * we can still get it from the connected panel later.
710			 */
711			if (channel->panel && channel->panel->funcs &&
712			    channel->panel->funcs->get_modes)
713				bus_format = 0;
714		}
715		if (bus_format < 0) {
716			dev_err(dev, "could not determine data mapping: %d\n",
717				bus_format);
718			return bus_format;
719		}
720		channel->bus_format = bus_format;
721
722		ret = imx_ldb_register(drm, channel);
723		if (ret)
724			return ret;
725	}
726
727	dev_set_drvdata(dev, imx_ldb);
728
729	return 0;
730}
731
732static void imx_ldb_unbind(struct device *dev, struct device *master,
733	void *data)
734{
735	struct imx_ldb *imx_ldb = dev_get_drvdata(dev);
736	int i;
737
738	for (i = 0; i < 2; i++) {
739		struct imx_ldb_channel *channel = &imx_ldb->channel[i];
740
741		if (channel->bridge)
742			drm_bridge_detach(channel->bridge);
743		if (channel->panel)
744			drm_panel_detach(channel->panel);
745
746		kfree(channel->edid);
747		i2c_put_adapter(channel->ddc);
748	}
749}
750
751static const struct component_ops imx_ldb_ops = {
752	.bind	= imx_ldb_bind,
753	.unbind	= imx_ldb_unbind,
754};
755
756static int imx_ldb_probe(struct platform_device *pdev)
757{
758	return component_add(&pdev->dev, &imx_ldb_ops);
759}
760
761static int imx_ldb_remove(struct platform_device *pdev)
762{
763	component_del(&pdev->dev, &imx_ldb_ops);
764	return 0;
765}
766
767static struct platform_driver imx_ldb_driver = {
768	.probe		= imx_ldb_probe,
769	.remove		= imx_ldb_remove,
770	.driver		= {
771		.of_match_table = imx_ldb_dt_ids,
772		.name	= DRIVER_NAME,
773	},
774};
775
776module_platform_driver(imx_ldb_driver);
777
778MODULE_DESCRIPTION("i.MX LVDS driver");
779MODULE_AUTHOR("Sascha Hauer, Pengutronix");
780MODULE_LICENSE("GPL");
781MODULE_ALIAS("platform:" DRIVER_NAME);