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