xref: /openbmc/linux/drivers/gpu/drm/imx/ipuv3/imx-ldb.c (revision 404e077a)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * i.MX drm driver - LVDS display bridge
4  *
5  * Copyright (C) 2012 Sascha Hauer, Pengutronix
6  */
7 
8 #include <linux/clk.h>
9 #include <linux/component.h>
10 #include <linux/i2c.h>
11 #include <linux/media-bus-format.h>
12 #include <linux/mfd/syscon.h>
13 #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
14 #include <linux/module.h>
15 #include <linux/of_device.h>
16 #include <linux/of_graph.h>
17 #include <linux/regmap.h>
18 #include <linux/videodev2.h>
19 
20 #include <video/of_display_timing.h>
21 #include <video/of_videomode.h>
22 
23 #include <drm/drm_atomic.h>
24 #include <drm/drm_atomic_helper.h>
25 #include <drm/drm_bridge.h>
26 #include <drm/drm_edid.h>
27 #include <drm/drm_managed.h>
28 #include <drm/drm_of.h>
29 #include <drm/drm_panel.h>
30 #include <drm/drm_print.h>
31 #include <drm/drm_probe_helper.h>
32 #include <drm/drm_simple_kms_helper.h>
33 
34 #include "imx-drm.h"
35 
36 #define DRIVER_NAME "imx-ldb"
37 
38 #define LDB_CH0_MODE_EN_TO_DI0		(1 << 0)
39 #define LDB_CH0_MODE_EN_TO_DI1		(3 << 0)
40 #define LDB_CH0_MODE_EN_MASK		(3 << 0)
41 #define LDB_CH1_MODE_EN_TO_DI0		(1 << 2)
42 #define LDB_CH1_MODE_EN_TO_DI1		(3 << 2)
43 #define LDB_CH1_MODE_EN_MASK		(3 << 2)
44 #define LDB_SPLIT_MODE_EN		(1 << 4)
45 #define LDB_DATA_WIDTH_CH0_24		(1 << 5)
46 #define LDB_BIT_MAP_CH0_JEIDA		(1 << 6)
47 #define LDB_DATA_WIDTH_CH1_24		(1 << 7)
48 #define LDB_BIT_MAP_CH1_JEIDA		(1 << 8)
49 #define LDB_DI0_VS_POL_ACT_LOW		(1 << 9)
50 #define LDB_DI1_VS_POL_ACT_LOW		(1 << 10)
51 #define LDB_BGREF_RMODE_INT		(1 << 15)
52 
53 struct imx_ldb_channel;
54 
55 struct imx_ldb_encoder {
56 	struct drm_connector connector;
57 	struct drm_encoder encoder;
58 	struct imx_ldb_channel *channel;
59 };
60 
61 struct imx_ldb;
62 
63 struct imx_ldb_channel {
64 	struct imx_ldb *ldb;
65 
66 	/* Defines what is connected to the ldb, only one at a time */
67 	struct drm_panel *panel;
68 	struct drm_bridge *bridge;
69 
70 	struct device_node *child;
71 	struct i2c_adapter *ddc;
72 	int chno;
73 	void *edid;
74 	struct drm_display_mode mode;
75 	int mode_valid;
76 	u32 bus_format;
77 	u32 bus_flags;
78 };
79 
80 static inline struct imx_ldb_channel *con_to_imx_ldb_ch(struct drm_connector *c)
81 {
82 	return container_of(c, struct imx_ldb_encoder, connector)->channel;
83 }
84 
85 static inline struct imx_ldb_channel *enc_to_imx_ldb_ch(struct drm_encoder *e)
86 {
87 	return container_of(e, struct imx_ldb_encoder, encoder)->channel;
88 }
89 
90 struct bus_mux {
91 	int reg;
92 	int shift;
93 	int mask;
94 };
95 
96 struct imx_ldb {
97 	struct regmap *regmap;
98 	struct device *dev;
99 	struct imx_ldb_channel channel[2];
100 	struct clk *clk[2]; /* our own clock */
101 	struct clk *clk_sel[4]; /* parent of display clock */
102 	struct clk *clk_parent[4]; /* original parent of clk_sel */
103 	struct clk *clk_pll[2]; /* upstream clock we can adjust */
104 	u32 ldb_ctrl;
105 	const struct bus_mux *lvds_mux;
106 };
107 
108 static void imx_ldb_ch_set_bus_format(struct imx_ldb_channel *imx_ldb_ch,
109 				      u32 bus_format)
110 {
111 	struct imx_ldb *ldb = imx_ldb_ch->ldb;
112 	int dual = ldb->ldb_ctrl & LDB_SPLIT_MODE_EN;
113 
114 	switch (bus_format) {
115 	case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
116 		break;
117 	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
118 		if (imx_ldb_ch->chno == 0 || dual)
119 			ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH0_24;
120 		if (imx_ldb_ch->chno == 1 || dual)
121 			ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH1_24;
122 		break;
123 	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
124 		if (imx_ldb_ch->chno == 0 || dual)
125 			ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH0_24 |
126 					 LDB_BIT_MAP_CH0_JEIDA;
127 		if (imx_ldb_ch->chno == 1 || dual)
128 			ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH1_24 |
129 					 LDB_BIT_MAP_CH1_JEIDA;
130 		break;
131 	}
132 }
133 
134 static int imx_ldb_connector_get_modes(struct drm_connector *connector)
135 {
136 	struct imx_ldb_channel *imx_ldb_ch = con_to_imx_ldb_ch(connector);
137 	int num_modes;
138 
139 	num_modes = drm_panel_get_modes(imx_ldb_ch->panel, connector);
140 	if (num_modes > 0)
141 		return num_modes;
142 
143 	if (!imx_ldb_ch->edid && imx_ldb_ch->ddc)
144 		imx_ldb_ch->edid = drm_get_edid(connector, imx_ldb_ch->ddc);
145 
146 	if (imx_ldb_ch->edid) {
147 		drm_connector_update_edid_property(connector,
148 							imx_ldb_ch->edid);
149 		num_modes = drm_add_edid_modes(connector, imx_ldb_ch->edid);
150 	}
151 
152 	if (imx_ldb_ch->mode_valid) {
153 		struct drm_display_mode *mode;
154 
155 		mode = drm_mode_duplicate(connector->dev, &imx_ldb_ch->mode);
156 		if (!mode)
157 			return -EINVAL;
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 
166 static void imx_ldb_set_clock(struct imx_ldb *ldb, int mux, int chno,
167 		unsigned long serial_clk, unsigned long di_clk)
168 {
169 	int ret;
170 
171 	dev_dbg(ldb->dev, "%s: now: %ld want: %ld\n", __func__,
172 			clk_get_rate(ldb->clk_pll[chno]), serial_clk);
173 	clk_set_rate(ldb->clk_pll[chno], serial_clk);
174 
175 	dev_dbg(ldb->dev, "%s after: %ld\n", __func__,
176 			clk_get_rate(ldb->clk_pll[chno]));
177 
178 	dev_dbg(ldb->dev, "%s: now: %ld want: %ld\n", __func__,
179 			clk_get_rate(ldb->clk[chno]),
180 			(long int)di_clk);
181 	clk_set_rate(ldb->clk[chno], di_clk);
182 
183 	dev_dbg(ldb->dev, "%s after: %ld\n", __func__,
184 			clk_get_rate(ldb->clk[chno]));
185 
186 	/* set display clock mux to LDB input clock */
187 	ret = clk_set_parent(ldb->clk_sel[mux], ldb->clk[chno]);
188 	if (ret)
189 		dev_err(ldb->dev,
190 			"unable to set di%d parent clock to ldb_di%d\n", mux,
191 			chno);
192 }
193 
194 static void imx_ldb_encoder_enable(struct drm_encoder *encoder)
195 {
196 	struct imx_ldb_channel *imx_ldb_ch = enc_to_imx_ldb_ch(encoder);
197 	struct imx_ldb *ldb = imx_ldb_ch->ldb;
198 	int dual = ldb->ldb_ctrl & LDB_SPLIT_MODE_EN;
199 	int mux = drm_of_encoder_active_port_id(imx_ldb_ch->child, encoder);
200 
201 	if (mux < 0 || mux >= ARRAY_SIZE(ldb->clk_sel)) {
202 		dev_warn(ldb->dev, "%s: invalid mux %d\n", __func__, mux);
203 		return;
204 	}
205 
206 	drm_panel_prepare(imx_ldb_ch->panel);
207 
208 	if (dual) {
209 		clk_set_parent(ldb->clk_sel[mux], ldb->clk[0]);
210 		clk_set_parent(ldb->clk_sel[mux], ldb->clk[1]);
211 
212 		clk_prepare_enable(ldb->clk[0]);
213 		clk_prepare_enable(ldb->clk[1]);
214 	} else {
215 		clk_set_parent(ldb->clk_sel[mux], ldb->clk[imx_ldb_ch->chno]);
216 	}
217 
218 	if (imx_ldb_ch == &ldb->channel[0] || dual) {
219 		ldb->ldb_ctrl &= ~LDB_CH0_MODE_EN_MASK;
220 		if (mux == 0 || ldb->lvds_mux)
221 			ldb->ldb_ctrl |= LDB_CH0_MODE_EN_TO_DI0;
222 		else if (mux == 1)
223 			ldb->ldb_ctrl |= LDB_CH0_MODE_EN_TO_DI1;
224 	}
225 	if (imx_ldb_ch == &ldb->channel[1] || dual) {
226 		ldb->ldb_ctrl &= ~LDB_CH1_MODE_EN_MASK;
227 		if (mux == 1 || ldb->lvds_mux)
228 			ldb->ldb_ctrl |= LDB_CH1_MODE_EN_TO_DI1;
229 		else if (mux == 0)
230 			ldb->ldb_ctrl |= LDB_CH1_MODE_EN_TO_DI0;
231 	}
232 
233 	if (ldb->lvds_mux) {
234 		const struct bus_mux *lvds_mux = NULL;
235 
236 		if (imx_ldb_ch == &ldb->channel[0])
237 			lvds_mux = &ldb->lvds_mux[0];
238 		else if (imx_ldb_ch == &ldb->channel[1])
239 			lvds_mux = &ldb->lvds_mux[1];
240 
241 		regmap_update_bits(ldb->regmap, lvds_mux->reg, lvds_mux->mask,
242 				   mux << lvds_mux->shift);
243 	}
244 
245 	regmap_write(ldb->regmap, IOMUXC_GPR2, ldb->ldb_ctrl);
246 
247 	drm_panel_enable(imx_ldb_ch->panel);
248 }
249 
250 static void
251 imx_ldb_encoder_atomic_mode_set(struct drm_encoder *encoder,
252 				struct drm_crtc_state *crtc_state,
253 				struct drm_connector_state *connector_state)
254 {
255 	struct imx_ldb_channel *imx_ldb_ch = enc_to_imx_ldb_ch(encoder);
256 	struct drm_display_mode *mode = &crtc_state->adjusted_mode;
257 	struct imx_ldb *ldb = imx_ldb_ch->ldb;
258 	int dual = ldb->ldb_ctrl & LDB_SPLIT_MODE_EN;
259 	unsigned long serial_clk;
260 	unsigned long di_clk = mode->clock * 1000;
261 	int mux = drm_of_encoder_active_port_id(imx_ldb_ch->child, encoder);
262 	u32 bus_format = imx_ldb_ch->bus_format;
263 
264 	if (mux < 0 || mux >= ARRAY_SIZE(ldb->clk_sel)) {
265 		dev_warn(ldb->dev, "%s: invalid mux %d\n", __func__, mux);
266 		return;
267 	}
268 
269 	if (mode->clock > 170000) {
270 		dev_warn(ldb->dev,
271 			 "%s: mode exceeds 170 MHz pixel clock\n", __func__);
272 	}
273 	if (mode->clock > 85000 && !dual) {
274 		dev_warn(ldb->dev,
275 			 "%s: mode exceeds 85 MHz pixel clock\n", __func__);
276 	}
277 
278 	if (!IS_ALIGNED(mode->hdisplay, 8)) {
279 		dev_warn(ldb->dev,
280 			 "%s: hdisplay does not align to 8 byte\n", __func__);
281 	}
282 
283 	if (dual) {
284 		serial_clk = 3500UL * mode->clock;
285 		imx_ldb_set_clock(ldb, mux, 0, serial_clk, di_clk);
286 		imx_ldb_set_clock(ldb, mux, 1, serial_clk, di_clk);
287 	} else {
288 		serial_clk = 7000UL * mode->clock;
289 		imx_ldb_set_clock(ldb, mux, imx_ldb_ch->chno, serial_clk,
290 				  di_clk);
291 	}
292 
293 	/* FIXME - assumes straight connections DI0 --> CH0, DI1 --> CH1 */
294 	if (imx_ldb_ch == &ldb->channel[0] || dual) {
295 		if (mode->flags & DRM_MODE_FLAG_NVSYNC)
296 			ldb->ldb_ctrl |= LDB_DI0_VS_POL_ACT_LOW;
297 		else if (mode->flags & DRM_MODE_FLAG_PVSYNC)
298 			ldb->ldb_ctrl &= ~LDB_DI0_VS_POL_ACT_LOW;
299 	}
300 	if (imx_ldb_ch == &ldb->channel[1] || dual) {
301 		if (mode->flags & DRM_MODE_FLAG_NVSYNC)
302 			ldb->ldb_ctrl |= LDB_DI1_VS_POL_ACT_LOW;
303 		else if (mode->flags & DRM_MODE_FLAG_PVSYNC)
304 			ldb->ldb_ctrl &= ~LDB_DI1_VS_POL_ACT_LOW;
305 	}
306 
307 	if (!bus_format) {
308 		struct drm_connector *connector = connector_state->connector;
309 		struct drm_display_info *di = &connector->display_info;
310 
311 		if (di->num_bus_formats)
312 			bus_format = di->bus_formats[0];
313 	}
314 	imx_ldb_ch_set_bus_format(imx_ldb_ch, bus_format);
315 }
316 
317 static void imx_ldb_encoder_disable(struct drm_encoder *encoder)
318 {
319 	struct imx_ldb_channel *imx_ldb_ch = enc_to_imx_ldb_ch(encoder);
320 	struct imx_ldb *ldb = imx_ldb_ch->ldb;
321 	int dual = ldb->ldb_ctrl & LDB_SPLIT_MODE_EN;
322 	int mux, ret;
323 
324 	drm_panel_disable(imx_ldb_ch->panel);
325 
326 	if (imx_ldb_ch == &ldb->channel[0] || dual)
327 		ldb->ldb_ctrl &= ~LDB_CH0_MODE_EN_MASK;
328 	if (imx_ldb_ch == &ldb->channel[1] || dual)
329 		ldb->ldb_ctrl &= ~LDB_CH1_MODE_EN_MASK;
330 
331 	regmap_write(ldb->regmap, IOMUXC_GPR2, ldb->ldb_ctrl);
332 
333 	if (dual) {
334 		clk_disable_unprepare(ldb->clk[0]);
335 		clk_disable_unprepare(ldb->clk[1]);
336 	}
337 
338 	if (ldb->lvds_mux) {
339 		const struct bus_mux *lvds_mux = NULL;
340 
341 		if (imx_ldb_ch == &ldb->channel[0])
342 			lvds_mux = &ldb->lvds_mux[0];
343 		else if (imx_ldb_ch == &ldb->channel[1])
344 			lvds_mux = &ldb->lvds_mux[1];
345 
346 		regmap_read(ldb->regmap, lvds_mux->reg, &mux);
347 		mux &= lvds_mux->mask;
348 		mux >>= lvds_mux->shift;
349 	} else {
350 		mux = (imx_ldb_ch == &ldb->channel[0]) ? 0 : 1;
351 	}
352 
353 	/* set display clock mux back to original input clock */
354 	ret = clk_set_parent(ldb->clk_sel[mux], ldb->clk_parent[mux]);
355 	if (ret)
356 		dev_err(ldb->dev,
357 			"unable to set di%d parent clock to original parent\n",
358 			mux);
359 
360 	drm_panel_unprepare(imx_ldb_ch->panel);
361 }
362 
363 static int imx_ldb_encoder_atomic_check(struct drm_encoder *encoder,
364 					struct drm_crtc_state *crtc_state,
365 					struct drm_connector_state *conn_state)
366 {
367 	struct imx_crtc_state *imx_crtc_state = to_imx_crtc_state(crtc_state);
368 	struct imx_ldb_channel *imx_ldb_ch = enc_to_imx_ldb_ch(encoder);
369 	struct drm_display_info *di = &conn_state->connector->display_info;
370 	u32 bus_format = imx_ldb_ch->bus_format;
371 
372 	/* Bus format description in DT overrides connector display info. */
373 	if (!bus_format && di->num_bus_formats) {
374 		bus_format = di->bus_formats[0];
375 		imx_crtc_state->bus_flags = di->bus_flags;
376 	} else {
377 		bus_format = imx_ldb_ch->bus_format;
378 		imx_crtc_state->bus_flags = imx_ldb_ch->bus_flags;
379 	}
380 	switch (bus_format) {
381 	case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
382 		imx_crtc_state->bus_format = MEDIA_BUS_FMT_RGB666_1X18;
383 		break;
384 	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
385 	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
386 		imx_crtc_state->bus_format = MEDIA_BUS_FMT_RGB888_1X24;
387 		break;
388 	default:
389 		return -EINVAL;
390 	}
391 
392 	imx_crtc_state->di_hsync_pin = 2;
393 	imx_crtc_state->di_vsync_pin = 3;
394 
395 	return 0;
396 }
397 
398 
399 static const struct drm_connector_funcs imx_ldb_connector_funcs = {
400 	.fill_modes = drm_helper_probe_single_connector_modes,
401 	.destroy = imx_drm_connector_destroy,
402 	.reset = drm_atomic_helper_connector_reset,
403 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
404 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
405 };
406 
407 static const struct drm_connector_helper_funcs imx_ldb_connector_helper_funcs = {
408 	.get_modes = imx_ldb_connector_get_modes,
409 };
410 
411 static const struct drm_encoder_helper_funcs imx_ldb_encoder_helper_funcs = {
412 	.atomic_mode_set = imx_ldb_encoder_atomic_mode_set,
413 	.enable = imx_ldb_encoder_enable,
414 	.disable = imx_ldb_encoder_disable,
415 	.atomic_check = imx_ldb_encoder_atomic_check,
416 };
417 
418 static int imx_ldb_get_clk(struct imx_ldb *ldb, int chno)
419 {
420 	char clkname[16];
421 
422 	snprintf(clkname, sizeof(clkname), "di%d", chno);
423 	ldb->clk[chno] = devm_clk_get(ldb->dev, clkname);
424 	if (IS_ERR(ldb->clk[chno]))
425 		return PTR_ERR(ldb->clk[chno]);
426 
427 	snprintf(clkname, sizeof(clkname), "di%d_pll", chno);
428 	ldb->clk_pll[chno] = devm_clk_get(ldb->dev, clkname);
429 
430 	return PTR_ERR_OR_ZERO(ldb->clk_pll[chno]);
431 }
432 
433 static int imx_ldb_register(struct drm_device *drm,
434 	struct imx_ldb_channel *imx_ldb_ch)
435 {
436 	struct imx_ldb *ldb = imx_ldb_ch->ldb;
437 	struct imx_ldb_encoder *ldb_encoder;
438 	struct drm_connector *connector;
439 	struct drm_encoder *encoder;
440 	int ret;
441 
442 	ldb_encoder = drmm_simple_encoder_alloc(drm, struct imx_ldb_encoder,
443 						encoder, DRM_MODE_ENCODER_LVDS);
444 	if (IS_ERR(ldb_encoder))
445 		return PTR_ERR(ldb_encoder);
446 
447 	ldb_encoder->channel = imx_ldb_ch;
448 	connector = &ldb_encoder->connector;
449 	encoder = &ldb_encoder->encoder;
450 
451 	ret = imx_drm_encoder_parse_of(drm, encoder, imx_ldb_ch->child);
452 	if (ret)
453 		return ret;
454 
455 	ret = imx_ldb_get_clk(ldb, imx_ldb_ch->chno);
456 	if (ret)
457 		return ret;
458 
459 	if (ldb->ldb_ctrl & LDB_SPLIT_MODE_EN) {
460 		ret = imx_ldb_get_clk(ldb, 1);
461 		if (ret)
462 			return ret;
463 	}
464 
465 	drm_encoder_helper_add(encoder, &imx_ldb_encoder_helper_funcs);
466 
467 	if (imx_ldb_ch->bridge) {
468 		ret = drm_bridge_attach(encoder, imx_ldb_ch->bridge, NULL, 0);
469 		if (ret)
470 			return ret;
471 	} else {
472 		/*
473 		 * We want to add the connector whenever there is no bridge
474 		 * that brings its own, not only when there is a panel. For
475 		 * historical reasons, the ldb driver can also work without
476 		 * a panel.
477 		 */
478 		drm_connector_helper_add(connector,
479 					 &imx_ldb_connector_helper_funcs);
480 		drm_connector_init_with_ddc(drm, connector,
481 					    &imx_ldb_connector_funcs,
482 					    DRM_MODE_CONNECTOR_LVDS,
483 					    imx_ldb_ch->ddc);
484 		drm_connector_attach_encoder(connector, encoder);
485 	}
486 
487 	return 0;
488 }
489 
490 struct imx_ldb_bit_mapping {
491 	u32 bus_format;
492 	u32 datawidth;
493 	const char * const mapping;
494 };
495 
496 static const struct imx_ldb_bit_mapping imx_ldb_bit_mappings[] = {
497 	{ MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,  18, "spwg" },
498 	{ MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,  24, "spwg" },
499 	{ MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA, 24, "jeida" },
500 };
501 
502 static u32 of_get_bus_format(struct device *dev, struct device_node *np)
503 {
504 	const char *bm;
505 	u32 datawidth = 0;
506 	int ret, i;
507 
508 	ret = of_property_read_string(np, "fsl,data-mapping", &bm);
509 	if (ret < 0)
510 		return ret;
511 
512 	of_property_read_u32(np, "fsl,data-width", &datawidth);
513 
514 	for (i = 0; i < ARRAY_SIZE(imx_ldb_bit_mappings); i++) {
515 		if (!strcasecmp(bm, imx_ldb_bit_mappings[i].mapping) &&
516 		    datawidth == imx_ldb_bit_mappings[i].datawidth)
517 			return imx_ldb_bit_mappings[i].bus_format;
518 	}
519 
520 	dev_err(dev, "invalid data mapping: %d-bit \"%s\"\n", datawidth, bm);
521 
522 	return -ENOENT;
523 }
524 
525 static struct bus_mux imx6q_lvds_mux[2] = {
526 	{
527 		.reg = IOMUXC_GPR3,
528 		.shift = 6,
529 		.mask = IMX6Q_GPR3_LVDS0_MUX_CTL_MASK,
530 	}, {
531 		.reg = IOMUXC_GPR3,
532 		.shift = 8,
533 		.mask = IMX6Q_GPR3_LVDS1_MUX_CTL_MASK,
534 	}
535 };
536 
537 /*
538  * For a device declaring compatible = "fsl,imx6q-ldb", "fsl,imx53-ldb",
539  * of_match_device will walk through this list and take the first entry
540  * matching any of its compatible values. Therefore, the more generic
541  * entries (in this case fsl,imx53-ldb) need to be ordered last.
542  */
543 static const struct of_device_id imx_ldb_dt_ids[] = {
544 	{ .compatible = "fsl,imx6q-ldb", .data = imx6q_lvds_mux, },
545 	{ .compatible = "fsl,imx53-ldb", .data = NULL, },
546 	{ }
547 };
548 MODULE_DEVICE_TABLE(of, imx_ldb_dt_ids);
549 
550 static int imx_ldb_panel_ddc(struct device *dev,
551 		struct imx_ldb_channel *channel, struct device_node *child)
552 {
553 	struct device_node *ddc_node;
554 	const u8 *edidp;
555 	int ret;
556 
557 	ddc_node = of_parse_phandle(child, "ddc-i2c-bus", 0);
558 	if (ddc_node) {
559 		channel->ddc = of_find_i2c_adapter_by_node(ddc_node);
560 		of_node_put(ddc_node);
561 		if (!channel->ddc) {
562 			dev_warn(dev, "failed to get ddc i2c adapter\n");
563 			return -EPROBE_DEFER;
564 		}
565 	}
566 
567 	if (!channel->ddc) {
568 		int edid_len;
569 
570 		/* if no DDC available, fallback to hardcoded EDID */
571 		dev_dbg(dev, "no ddc available\n");
572 
573 		edidp = of_get_property(child, "edid", &edid_len);
574 		if (edidp) {
575 			channel->edid = kmemdup(edidp, edid_len, GFP_KERNEL);
576 			if (!channel->edid)
577 				return -ENOMEM;
578 		} else if (!channel->panel) {
579 			/* fallback to display-timings node */
580 			ret = of_get_drm_display_mode(child,
581 						      &channel->mode,
582 						      &channel->bus_flags,
583 						      OF_USE_NATIVE_MODE);
584 			if (!ret)
585 				channel->mode_valid = 1;
586 		}
587 	}
588 	return 0;
589 }
590 
591 static int imx_ldb_bind(struct device *dev, struct device *master, void *data)
592 {
593 	struct drm_device *drm = data;
594 	struct imx_ldb *imx_ldb = dev_get_drvdata(dev);
595 	int ret;
596 	int i;
597 
598 	for (i = 0; i < 2; i++) {
599 		struct imx_ldb_channel *channel = &imx_ldb->channel[i];
600 
601 		if (!channel->ldb)
602 			continue;
603 
604 		ret = imx_ldb_register(drm, channel);
605 		if (ret)
606 			return ret;
607 	}
608 
609 	return 0;
610 }
611 
612 static const struct component_ops imx_ldb_ops = {
613 	.bind	= imx_ldb_bind,
614 };
615 
616 static int imx_ldb_probe(struct platform_device *pdev)
617 {
618 	struct device *dev = &pdev->dev;
619 	struct device_node *np = dev->of_node;
620 	const struct of_device_id *of_id = of_match_device(imx_ldb_dt_ids, dev);
621 	struct device_node *child;
622 	struct imx_ldb *imx_ldb;
623 	int dual;
624 	int ret;
625 	int i;
626 
627 	imx_ldb = devm_kzalloc(dev, sizeof(*imx_ldb), GFP_KERNEL);
628 	if (!imx_ldb)
629 		return -ENOMEM;
630 
631 	imx_ldb->regmap = syscon_regmap_lookup_by_phandle(np, "gpr");
632 	if (IS_ERR(imx_ldb->regmap)) {
633 		dev_err(dev, "failed to get parent regmap\n");
634 		return PTR_ERR(imx_ldb->regmap);
635 	}
636 
637 	/* disable LDB by resetting the control register to POR default */
638 	regmap_write(imx_ldb->regmap, IOMUXC_GPR2, 0);
639 
640 	imx_ldb->dev = dev;
641 
642 	if (of_id)
643 		imx_ldb->lvds_mux = of_id->data;
644 
645 	dual = of_property_read_bool(np, "fsl,dual-channel");
646 	if (dual)
647 		imx_ldb->ldb_ctrl |= LDB_SPLIT_MODE_EN;
648 
649 	/*
650 	 * There are three different possible clock mux configurations:
651 	 * i.MX53:  ipu1_di0_sel, ipu1_di1_sel
652 	 * i.MX6q:  ipu1_di0_sel, ipu1_di1_sel, ipu2_di0_sel, ipu2_di1_sel
653 	 * i.MX6dl: ipu1_di0_sel, ipu1_di1_sel, lcdif_sel
654 	 * Map them all to di0_sel...di3_sel.
655 	 */
656 	for (i = 0; i < 4; i++) {
657 		char clkname[16];
658 
659 		sprintf(clkname, "di%d_sel", i);
660 		imx_ldb->clk_sel[i] = devm_clk_get(imx_ldb->dev, clkname);
661 		if (IS_ERR(imx_ldb->clk_sel[i])) {
662 			ret = PTR_ERR(imx_ldb->clk_sel[i]);
663 			imx_ldb->clk_sel[i] = NULL;
664 			break;
665 		}
666 
667 		imx_ldb->clk_parent[i] = clk_get_parent(imx_ldb->clk_sel[i]);
668 	}
669 	if (i == 0)
670 		return ret;
671 
672 	for_each_child_of_node(np, child) {
673 		struct imx_ldb_channel *channel;
674 		int bus_format;
675 
676 		ret = of_property_read_u32(child, "reg", &i);
677 		if (ret || i < 0 || i > 1) {
678 			ret = -EINVAL;
679 			goto free_child;
680 		}
681 
682 		if (!of_device_is_available(child))
683 			continue;
684 
685 		if (dual && i > 0) {
686 			dev_warn(dev, "dual-channel mode, ignoring second output\n");
687 			continue;
688 		}
689 
690 		channel = &imx_ldb->channel[i];
691 		channel->ldb = imx_ldb;
692 		channel->chno = i;
693 
694 		/*
695 		 * The output port is port@4 with an external 4-port mux or
696 		 * port@2 with the internal 2-port mux.
697 		 */
698 		ret = drm_of_find_panel_or_bridge(child,
699 						  imx_ldb->lvds_mux ? 4 : 2, 0,
700 						  &channel->panel, &channel->bridge);
701 		if (ret && ret != -ENODEV)
702 			goto free_child;
703 
704 		/* panel ddc only if there is no bridge */
705 		if (!channel->bridge) {
706 			ret = imx_ldb_panel_ddc(dev, channel, child);
707 			if (ret)
708 				goto free_child;
709 		}
710 
711 		bus_format = of_get_bus_format(dev, child);
712 		if (bus_format == -EINVAL) {
713 			/*
714 			 * If no bus format was specified in the device tree,
715 			 * we can still get it from the connected panel later.
716 			 */
717 			if (channel->panel && channel->panel->funcs &&
718 			    channel->panel->funcs->get_modes)
719 				bus_format = 0;
720 		}
721 		if (bus_format < 0) {
722 			dev_err(dev, "could not determine data mapping: %d\n",
723 				bus_format);
724 			ret = bus_format;
725 			goto free_child;
726 		}
727 		channel->bus_format = bus_format;
728 		channel->child = child;
729 	}
730 
731 	platform_set_drvdata(pdev, imx_ldb);
732 
733 	return component_add(&pdev->dev, &imx_ldb_ops);
734 
735 free_child:
736 	of_node_put(child);
737 	return ret;
738 }
739 
740 static int imx_ldb_remove(struct platform_device *pdev)
741 {
742 	struct imx_ldb *imx_ldb = platform_get_drvdata(pdev);
743 	int i;
744 
745 	for (i = 0; i < 2; i++) {
746 		struct imx_ldb_channel *channel = &imx_ldb->channel[i];
747 
748 		kfree(channel->edid);
749 		i2c_put_adapter(channel->ddc);
750 	}
751 
752 	component_del(&pdev->dev, &imx_ldb_ops);
753 	return 0;
754 }
755 
756 static struct platform_driver imx_ldb_driver = {
757 	.probe		= imx_ldb_probe,
758 	.remove		= imx_ldb_remove,
759 	.driver		= {
760 		.of_match_table = imx_ldb_dt_ids,
761 		.name	= DRIVER_NAME,
762 	},
763 };
764 
765 module_platform_driver(imx_ldb_driver);
766 
767 MODULE_DESCRIPTION("i.MX LVDS driver");
768 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
769 MODULE_LICENSE("GPL");
770 MODULE_ALIAS("platform:" DRIVER_NAME);
771