1 // SPDX-License-Identifier: GPL-2.0+
2 
3 /*
4  * Copyright 2020 NXP
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/media-bus-format.h>
9 #include <linux/mfd/syscon.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/of_device.h>
13 #include <linux/of_graph.h>
14 #include <linux/phy/phy.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/regmap.h>
17 
18 #include <drm/drm_atomic_state_helper.h>
19 #include <drm/drm_bridge.h>
20 #include <drm/drm_connector.h>
21 #include <drm/drm_fourcc.h>
22 #include <drm/drm_of.h>
23 #include <drm/drm_print.h>
24 
25 #include "imx-ldb-helper.h"
26 
27 #define  LDB_CH_SEL		BIT(28)
28 
29 #define SS_CTRL			0x20
30 #define  CH_HSYNC_M(id)		BIT(0 + ((id) * 2))
31 #define  CH_VSYNC_M(id)		BIT(1 + ((id) * 2))
32 #define  CH_PHSYNC(id)		BIT(0 + ((id) * 2))
33 #define  CH_PVSYNC(id)		BIT(1 + ((id) * 2))
34 
35 #define DRIVER_NAME		"imx8qxp-ldb"
36 
37 struct imx8qxp_ldb_channel {
38 	struct ldb_channel base;
39 	struct phy *phy;
40 	unsigned int di_id;
41 };
42 
43 struct imx8qxp_ldb {
44 	struct ldb base;
45 	struct device *dev;
46 	struct imx8qxp_ldb_channel channel[MAX_LDB_CHAN_NUM];
47 	struct clk *clk_pixel;
48 	struct clk *clk_bypass;
49 	struct drm_bridge *companion;
50 	int active_chno;
51 };
52 
53 static inline struct imx8qxp_ldb_channel *
base_to_imx8qxp_ldb_channel(struct ldb_channel * base)54 base_to_imx8qxp_ldb_channel(struct ldb_channel *base)
55 {
56 	return container_of(base, struct imx8qxp_ldb_channel, base);
57 }
58 
base_to_imx8qxp_ldb(struct ldb * base)59 static inline struct imx8qxp_ldb *base_to_imx8qxp_ldb(struct ldb *base)
60 {
61 	return container_of(base, struct imx8qxp_ldb, base);
62 }
63 
imx8qxp_ldb_set_phy_cfg(struct imx8qxp_ldb * imx8qxp_ldb,unsigned long di_clk,bool is_split,struct phy_configure_opts_lvds * phy_cfg)64 static void imx8qxp_ldb_set_phy_cfg(struct imx8qxp_ldb *imx8qxp_ldb,
65 				    unsigned long di_clk, bool is_split,
66 				    struct phy_configure_opts_lvds *phy_cfg)
67 {
68 	phy_cfg->bits_per_lane_and_dclk_cycle = 7;
69 	phy_cfg->lanes = 4;
70 
71 	if (is_split) {
72 		phy_cfg->differential_clk_rate = di_clk / 2;
73 		phy_cfg->is_slave = !imx8qxp_ldb->companion;
74 	} else {
75 		phy_cfg->differential_clk_rate = di_clk;
76 		phy_cfg->is_slave = false;
77 	}
78 }
79 
80 static int
imx8qxp_ldb_bridge_atomic_check(struct drm_bridge * bridge,struct drm_bridge_state * bridge_state,struct drm_crtc_state * crtc_state,struct drm_connector_state * conn_state)81 imx8qxp_ldb_bridge_atomic_check(struct drm_bridge *bridge,
82 				struct drm_bridge_state *bridge_state,
83 				struct drm_crtc_state *crtc_state,
84 				struct drm_connector_state *conn_state)
85 {
86 	struct ldb_channel *ldb_ch = bridge->driver_private;
87 	struct ldb *ldb = ldb_ch->ldb;
88 	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch =
89 					base_to_imx8qxp_ldb_channel(ldb_ch);
90 	struct imx8qxp_ldb *imx8qxp_ldb = base_to_imx8qxp_ldb(ldb);
91 	struct drm_bridge *companion = imx8qxp_ldb->companion;
92 	struct drm_display_mode *adj = &crtc_state->adjusted_mode;
93 	unsigned long di_clk = adj->clock * 1000;
94 	bool is_split = ldb_channel_is_split_link(ldb_ch);
95 	union phy_configure_opts opts = { };
96 	struct phy_configure_opts_lvds *phy_cfg = &opts.lvds;
97 	int ret;
98 
99 	ret = ldb_bridge_atomic_check_helper(bridge, bridge_state,
100 					     crtc_state, conn_state);
101 	if (ret)
102 		return ret;
103 
104 	imx8qxp_ldb_set_phy_cfg(imx8qxp_ldb, di_clk, is_split, phy_cfg);
105 	ret = phy_validate(imx8qxp_ldb_ch->phy, PHY_MODE_LVDS, 0, &opts);
106 	if (ret < 0) {
107 		DRM_DEV_DEBUG_DRIVER(imx8qxp_ldb->dev,
108 				     "failed to validate PHY: %d\n", ret);
109 		return ret;
110 	}
111 
112 	if (is_split && companion) {
113 		ret = companion->funcs->atomic_check(companion,
114 					bridge_state, crtc_state, conn_state);
115 		if (ret)
116 			return ret;
117 	}
118 
119 	return ret;
120 }
121 
122 static void
imx8qxp_ldb_bridge_mode_set(struct drm_bridge * bridge,const struct drm_display_mode * mode,const struct drm_display_mode * adjusted_mode)123 imx8qxp_ldb_bridge_mode_set(struct drm_bridge *bridge,
124 			    const struct drm_display_mode *mode,
125 			    const struct drm_display_mode *adjusted_mode)
126 {
127 	struct ldb_channel *ldb_ch = bridge->driver_private;
128 	struct ldb_channel *companion_ldb_ch;
129 	struct ldb *ldb = ldb_ch->ldb;
130 	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch =
131 					base_to_imx8qxp_ldb_channel(ldb_ch);
132 	struct imx8qxp_ldb *imx8qxp_ldb = base_to_imx8qxp_ldb(ldb);
133 	struct drm_bridge *companion = imx8qxp_ldb->companion;
134 	struct device *dev = imx8qxp_ldb->dev;
135 	unsigned long di_clk = adjusted_mode->clock * 1000;
136 	bool is_split = ldb_channel_is_split_link(ldb_ch);
137 	union phy_configure_opts opts = { };
138 	struct phy_configure_opts_lvds *phy_cfg = &opts.lvds;
139 	u32 chno = ldb_ch->chno;
140 	int ret;
141 
142 	ret = pm_runtime_get_sync(dev);
143 	if (ret < 0)
144 		DRM_DEV_ERROR(dev, "failed to get runtime PM sync: %d\n", ret);
145 
146 	ret = phy_init(imx8qxp_ldb_ch->phy);
147 	if (ret < 0)
148 		DRM_DEV_ERROR(dev, "failed to initialize PHY: %d\n", ret);
149 
150 	ret = phy_set_mode(imx8qxp_ldb_ch->phy, PHY_MODE_LVDS);
151 	if (ret < 0)
152 		DRM_DEV_ERROR(dev, "failed to set PHY mode: %d\n", ret);
153 
154 	if (is_split && companion) {
155 		companion_ldb_ch = bridge_to_ldb_ch(companion);
156 
157 		companion_ldb_ch->in_bus_format = ldb_ch->in_bus_format;
158 		companion_ldb_ch->out_bus_format = ldb_ch->out_bus_format;
159 	}
160 
161 	clk_set_rate(imx8qxp_ldb->clk_bypass, di_clk);
162 	clk_set_rate(imx8qxp_ldb->clk_pixel, di_clk);
163 
164 	imx8qxp_ldb_set_phy_cfg(imx8qxp_ldb, di_clk, is_split, phy_cfg);
165 	ret = phy_configure(imx8qxp_ldb_ch->phy, &opts);
166 	if (ret < 0)
167 		DRM_DEV_ERROR(dev, "failed to configure PHY: %d\n", ret);
168 
169 	if (chno == 0)
170 		ldb->ldb_ctrl &= ~LDB_CH_SEL;
171 	else
172 		ldb->ldb_ctrl |= LDB_CH_SEL;
173 
174 	/* input VSYNC signal from pixel link is active low */
175 	if (imx8qxp_ldb_ch->di_id == 0)
176 		ldb->ldb_ctrl |= LDB_DI0_VS_POL_ACT_LOW;
177 	else
178 		ldb->ldb_ctrl |= LDB_DI1_VS_POL_ACT_LOW;
179 
180 	/*
181 	 * For split mode, settle input VSYNC signal polarity and
182 	 * channel selection down early.
183 	 */
184 	if (is_split)
185 		regmap_write(ldb->regmap, ldb->ctrl_reg, ldb->ldb_ctrl);
186 
187 	ldb_bridge_mode_set_helper(bridge, mode, adjusted_mode);
188 
189 	if (adjusted_mode->flags & DRM_MODE_FLAG_NVSYNC)
190 		regmap_update_bits(ldb->regmap, SS_CTRL, CH_VSYNC_M(chno), 0);
191 	else if (adjusted_mode->flags & DRM_MODE_FLAG_PVSYNC)
192 		regmap_update_bits(ldb->regmap, SS_CTRL,
193 				   CH_VSYNC_M(chno), CH_PVSYNC(chno));
194 
195 	if (adjusted_mode->flags & DRM_MODE_FLAG_NHSYNC)
196 		regmap_update_bits(ldb->regmap, SS_CTRL, CH_HSYNC_M(chno), 0);
197 	else if (adjusted_mode->flags & DRM_MODE_FLAG_PHSYNC)
198 		regmap_update_bits(ldb->regmap, SS_CTRL,
199 				   CH_HSYNC_M(chno), CH_PHSYNC(chno));
200 
201 	if (is_split && companion)
202 		companion->funcs->mode_set(companion, mode, adjusted_mode);
203 }
204 
205 static void
imx8qxp_ldb_bridge_atomic_pre_enable(struct drm_bridge * bridge,struct drm_bridge_state * old_bridge_state)206 imx8qxp_ldb_bridge_atomic_pre_enable(struct drm_bridge *bridge,
207 				     struct drm_bridge_state *old_bridge_state)
208 {
209 	struct ldb_channel *ldb_ch = bridge->driver_private;
210 	struct ldb *ldb = ldb_ch->ldb;
211 	struct imx8qxp_ldb *imx8qxp_ldb = base_to_imx8qxp_ldb(ldb);
212 	struct drm_bridge *companion = imx8qxp_ldb->companion;
213 	bool is_split = ldb_channel_is_split_link(ldb_ch);
214 
215 	clk_prepare_enable(imx8qxp_ldb->clk_pixel);
216 	clk_prepare_enable(imx8qxp_ldb->clk_bypass);
217 
218 	if (is_split && companion)
219 		companion->funcs->atomic_pre_enable(companion, old_bridge_state);
220 }
221 
222 static void
imx8qxp_ldb_bridge_atomic_enable(struct drm_bridge * bridge,struct drm_bridge_state * old_bridge_state)223 imx8qxp_ldb_bridge_atomic_enable(struct drm_bridge *bridge,
224 				 struct drm_bridge_state *old_bridge_state)
225 {
226 	struct ldb_channel *ldb_ch = bridge->driver_private;
227 	struct ldb *ldb = ldb_ch->ldb;
228 	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch =
229 					base_to_imx8qxp_ldb_channel(ldb_ch);
230 	struct imx8qxp_ldb *imx8qxp_ldb = base_to_imx8qxp_ldb(ldb);
231 	struct drm_bridge *companion = imx8qxp_ldb->companion;
232 	struct device *dev = imx8qxp_ldb->dev;
233 	bool is_split = ldb_channel_is_split_link(ldb_ch);
234 	int ret;
235 
236 	if (ldb_ch->chno == 0 || is_split) {
237 		ldb->ldb_ctrl &= ~LDB_CH0_MODE_EN_MASK;
238 		ldb->ldb_ctrl |= imx8qxp_ldb_ch->di_id == 0 ?
239 				LDB_CH0_MODE_EN_TO_DI0 : LDB_CH0_MODE_EN_TO_DI1;
240 	}
241 	if (ldb_ch->chno == 1 || is_split) {
242 		ldb->ldb_ctrl &= ~LDB_CH1_MODE_EN_MASK;
243 		ldb->ldb_ctrl |= imx8qxp_ldb_ch->di_id == 0 ?
244 				LDB_CH1_MODE_EN_TO_DI0 : LDB_CH1_MODE_EN_TO_DI1;
245 	}
246 
247 	ldb_bridge_enable_helper(bridge);
248 
249 	ret = phy_power_on(imx8qxp_ldb_ch->phy);
250 	if (ret)
251 		DRM_DEV_ERROR(dev, "failed to power on PHY: %d\n", ret);
252 
253 	if (is_split && companion)
254 		companion->funcs->atomic_enable(companion, old_bridge_state);
255 }
256 
257 static void
imx8qxp_ldb_bridge_atomic_disable(struct drm_bridge * bridge,struct drm_bridge_state * old_bridge_state)258 imx8qxp_ldb_bridge_atomic_disable(struct drm_bridge *bridge,
259 				  struct drm_bridge_state *old_bridge_state)
260 {
261 	struct ldb_channel *ldb_ch = bridge->driver_private;
262 	struct ldb *ldb = ldb_ch->ldb;
263 	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch =
264 					base_to_imx8qxp_ldb_channel(ldb_ch);
265 	struct imx8qxp_ldb *imx8qxp_ldb = base_to_imx8qxp_ldb(ldb);
266 	struct drm_bridge *companion = imx8qxp_ldb->companion;
267 	struct device *dev = imx8qxp_ldb->dev;
268 	bool is_split = ldb_channel_is_split_link(ldb_ch);
269 	int ret;
270 
271 	ret = phy_power_off(imx8qxp_ldb_ch->phy);
272 	if (ret)
273 		DRM_DEV_ERROR(dev, "failed to power off PHY: %d\n", ret);
274 
275 	ret = phy_exit(imx8qxp_ldb_ch->phy);
276 	if (ret < 0)
277 		DRM_DEV_ERROR(dev, "failed to teardown PHY: %d\n", ret);
278 
279 	ldb_bridge_disable_helper(bridge);
280 
281 	clk_disable_unprepare(imx8qxp_ldb->clk_bypass);
282 	clk_disable_unprepare(imx8qxp_ldb->clk_pixel);
283 
284 	if (is_split && companion)
285 		companion->funcs->atomic_disable(companion, old_bridge_state);
286 
287 	ret = pm_runtime_put(dev);
288 	if (ret < 0)
289 		DRM_DEV_ERROR(dev, "failed to put runtime PM: %d\n", ret);
290 }
291 
292 static const u32 imx8qxp_ldb_bus_output_fmts[] = {
293 	MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,
294 	MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,
295 	MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA,
296 	MEDIA_BUS_FMT_FIXED,
297 };
298 
imx8qxp_ldb_bus_output_fmt_supported(u32 fmt)299 static bool imx8qxp_ldb_bus_output_fmt_supported(u32 fmt)
300 {
301 	int i;
302 
303 	for (i = 0; i < ARRAY_SIZE(imx8qxp_ldb_bus_output_fmts); i++) {
304 		if (imx8qxp_ldb_bus_output_fmts[i] == fmt)
305 			return true;
306 	}
307 
308 	return false;
309 }
310 
311 static u32 *
imx8qxp_ldb_bridge_atomic_get_input_bus_fmts(struct drm_bridge * bridge,struct drm_bridge_state * bridge_state,struct drm_crtc_state * crtc_state,struct drm_connector_state * conn_state,u32 output_fmt,unsigned int * num_input_fmts)312 imx8qxp_ldb_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
313 					     struct drm_bridge_state *bridge_state,
314 					     struct drm_crtc_state *crtc_state,
315 					     struct drm_connector_state *conn_state,
316 					     u32 output_fmt,
317 					     unsigned int *num_input_fmts)
318 {
319 	struct drm_display_info *di;
320 	const struct drm_format_info *finfo;
321 	u32 *input_fmts;
322 
323 	if (!imx8qxp_ldb_bus_output_fmt_supported(output_fmt))
324 		return NULL;
325 
326 	*num_input_fmts = 1;
327 
328 	input_fmts = kmalloc(sizeof(*input_fmts), GFP_KERNEL);
329 	if (!input_fmts)
330 		return NULL;
331 
332 	switch (output_fmt) {
333 	case MEDIA_BUS_FMT_FIXED:
334 		di = &conn_state->connector->display_info;
335 
336 		/*
337 		 * Look at the first bus format to determine input format.
338 		 * Default to MEDIA_BUS_FMT_RGB888_1X24, if no match.
339 		 */
340 		if (di->num_bus_formats) {
341 			finfo = drm_format_info(di->bus_formats[0]);
342 
343 			input_fmts[0] = finfo->depth == 18 ?
344 					MEDIA_BUS_FMT_RGB666_1X24_CPADHI :
345 					MEDIA_BUS_FMT_RGB888_1X24;
346 		} else {
347 			input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
348 		}
349 		break;
350 	case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
351 		input_fmts[0] = MEDIA_BUS_FMT_RGB666_1X24_CPADHI;
352 		break;
353 	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
354 	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
355 		input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
356 		break;
357 	default:
358 		kfree(input_fmts);
359 		input_fmts = NULL;
360 		break;
361 	}
362 
363 	return input_fmts;
364 }
365 
366 static u32 *
imx8qxp_ldb_bridge_atomic_get_output_bus_fmts(struct drm_bridge * bridge,struct drm_bridge_state * bridge_state,struct drm_crtc_state * crtc_state,struct drm_connector_state * conn_state,unsigned int * num_output_fmts)367 imx8qxp_ldb_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
368 					      struct drm_bridge_state *bridge_state,
369 					      struct drm_crtc_state *crtc_state,
370 					      struct drm_connector_state *conn_state,
371 					      unsigned int *num_output_fmts)
372 {
373 	*num_output_fmts = ARRAY_SIZE(imx8qxp_ldb_bus_output_fmts);
374 	return kmemdup(imx8qxp_ldb_bus_output_fmts,
375 			sizeof(imx8qxp_ldb_bus_output_fmts), GFP_KERNEL);
376 }
377 
378 static enum drm_mode_status
imx8qxp_ldb_bridge_mode_valid(struct drm_bridge * bridge,const struct drm_display_info * info,const struct drm_display_mode * mode)379 imx8qxp_ldb_bridge_mode_valid(struct drm_bridge *bridge,
380 			      const struct drm_display_info *info,
381 			      const struct drm_display_mode *mode)
382 {
383 	struct ldb_channel *ldb_ch = bridge->driver_private;
384 	bool is_single = ldb_channel_is_single_link(ldb_ch);
385 
386 	if (mode->clock > 170000)
387 		return MODE_CLOCK_HIGH;
388 
389 	if (mode->clock > 150000 && is_single)
390 		return MODE_CLOCK_HIGH;
391 
392 	return MODE_OK;
393 }
394 
395 static const struct drm_bridge_funcs imx8qxp_ldb_bridge_funcs = {
396 	.atomic_duplicate_state	= drm_atomic_helper_bridge_duplicate_state,
397 	.atomic_destroy_state	= drm_atomic_helper_bridge_destroy_state,
398 	.atomic_reset		= drm_atomic_helper_bridge_reset,
399 	.mode_valid		= imx8qxp_ldb_bridge_mode_valid,
400 	.attach			= ldb_bridge_attach_helper,
401 	.atomic_check		= imx8qxp_ldb_bridge_atomic_check,
402 	.mode_set		= imx8qxp_ldb_bridge_mode_set,
403 	.atomic_pre_enable	= imx8qxp_ldb_bridge_atomic_pre_enable,
404 	.atomic_enable		= imx8qxp_ldb_bridge_atomic_enable,
405 	.atomic_disable		= imx8qxp_ldb_bridge_atomic_disable,
406 	.atomic_get_input_bus_fmts =
407 			imx8qxp_ldb_bridge_atomic_get_input_bus_fmts,
408 	.atomic_get_output_bus_fmts =
409 			imx8qxp_ldb_bridge_atomic_get_output_bus_fmts,
410 };
411 
imx8qxp_ldb_set_di_id(struct imx8qxp_ldb * imx8qxp_ldb)412 static int imx8qxp_ldb_set_di_id(struct imx8qxp_ldb *imx8qxp_ldb)
413 {
414 	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch =
415 			 &imx8qxp_ldb->channel[imx8qxp_ldb->active_chno];
416 	struct ldb_channel *ldb_ch = &imx8qxp_ldb_ch->base;
417 	struct device_node *ep, *remote;
418 	struct device *dev = imx8qxp_ldb->dev;
419 	struct of_endpoint endpoint;
420 	int ret;
421 
422 	ep = of_graph_get_endpoint_by_regs(ldb_ch->np, 0, -1);
423 	if (!ep) {
424 		DRM_DEV_ERROR(dev, "failed to get port0 endpoint\n");
425 		return -EINVAL;
426 	}
427 
428 	remote = of_graph_get_remote_endpoint(ep);
429 	of_node_put(ep);
430 	if (!remote) {
431 		DRM_DEV_ERROR(dev, "failed to get port0 remote endpoint\n");
432 		return -EINVAL;
433 	}
434 
435 	ret = of_graph_parse_endpoint(remote, &endpoint);
436 	of_node_put(remote);
437 	if (ret) {
438 		DRM_DEV_ERROR(dev, "failed to parse port0 remote endpoint: %d\n",
439 			      ret);
440 		return ret;
441 	}
442 
443 	imx8qxp_ldb_ch->di_id = endpoint.id;
444 
445 	return 0;
446 }
447 
448 static int
imx8qxp_ldb_check_chno_and_dual_link(struct ldb_channel * ldb_ch,int link)449 imx8qxp_ldb_check_chno_and_dual_link(struct ldb_channel *ldb_ch, int link)
450 {
451 	if ((link == DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS && ldb_ch->chno != 0) ||
452 	    (link == DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS && ldb_ch->chno != 1))
453 		return -EINVAL;
454 
455 	return 0;
456 }
457 
imx8qxp_ldb_parse_dt_companion(struct imx8qxp_ldb * imx8qxp_ldb)458 static int imx8qxp_ldb_parse_dt_companion(struct imx8qxp_ldb *imx8qxp_ldb)
459 {
460 	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch =
461 			 &imx8qxp_ldb->channel[imx8qxp_ldb->active_chno];
462 	struct ldb_channel *ldb_ch = &imx8qxp_ldb_ch->base;
463 	struct ldb_channel *companion_ldb_ch;
464 	struct device_node *companion;
465 	struct device_node *child;
466 	struct device_node *companion_port = NULL;
467 	struct device_node *port1, *port2;
468 	struct device *dev = imx8qxp_ldb->dev;
469 	const struct of_device_id *match;
470 	u32 i;
471 	int dual_link;
472 	int ret;
473 
474 	/* Locate the companion LDB for dual-link operation, if any. */
475 	companion = of_parse_phandle(dev->of_node, "fsl,companion-ldb", 0);
476 	if (!companion)
477 		return 0;
478 
479 	if (!of_device_is_available(companion)) {
480 		DRM_DEV_ERROR(dev, "companion LDB is not available\n");
481 		ret = -ENODEV;
482 		goto out;
483 	}
484 
485 	/*
486 	 * Sanity check: the companion bridge must have the same compatible
487 	 * string.
488 	 */
489 	match = of_match_device(dev->driver->of_match_table, dev);
490 	if (!of_device_is_compatible(companion, match->compatible)) {
491 		DRM_DEV_ERROR(dev, "companion LDB is incompatible\n");
492 		ret = -ENXIO;
493 		goto out;
494 	}
495 
496 	for_each_available_child_of_node(companion, child) {
497 		ret = of_property_read_u32(child, "reg", &i);
498 		if (ret || i > MAX_LDB_CHAN_NUM - 1) {
499 			DRM_DEV_ERROR(dev,
500 				      "invalid channel node address: %u\n", i);
501 			ret = -EINVAL;
502 			of_node_put(child);
503 			goto out;
504 		}
505 
506 		/*
507 		 * Channel numbers have to be different, because channel0
508 		 * transmits odd pixels and channel1 transmits even pixels.
509 		 */
510 		if (i == (ldb_ch->chno ^ 0x1)) {
511 			companion_port = child;
512 			break;
513 		}
514 	}
515 
516 	if (!companion_port) {
517 		DRM_DEV_ERROR(dev,
518 			      "failed to find companion LDB channel port\n");
519 		ret = -EINVAL;
520 		goto out;
521 	}
522 
523 	/*
524 	 * We need to work out if the sink is expecting us to function in
525 	 * dual-link mode.  We do this by looking at the DT port nodes we are
526 	 * connected to.  If they are marked as expecting odd pixels and
527 	 * even pixels than we need to enable LDB split mode.
528 	 */
529 	port1 = of_graph_get_port_by_id(ldb_ch->np, 1);
530 	port2 = of_graph_get_port_by_id(companion_port, 1);
531 	dual_link = drm_of_lvds_get_dual_link_pixel_order(port1, port2);
532 	of_node_put(port1);
533 	of_node_put(port2);
534 
535 	switch (dual_link) {
536 	case DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS:
537 		ldb_ch->link_type = LDB_CH_DUAL_LINK_ODD_EVEN_PIXELS;
538 		break;
539 	case DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS:
540 		ldb_ch->link_type = LDB_CH_DUAL_LINK_EVEN_ODD_PIXELS;
541 		break;
542 	default:
543 		ret = dual_link;
544 		DRM_DEV_ERROR(dev,
545 			      "failed to get dual link pixel order: %d\n", ret);
546 		goto out;
547 	}
548 
549 	ret = imx8qxp_ldb_check_chno_and_dual_link(ldb_ch, dual_link);
550 	if (ret < 0) {
551 		DRM_DEV_ERROR(dev,
552 			      "unmatched channel number(%u) vs dual link(%d)\n",
553 			      ldb_ch->chno, dual_link);
554 		goto out;
555 	}
556 
557 	imx8qxp_ldb->companion = of_drm_find_bridge(companion_port);
558 	if (!imx8qxp_ldb->companion) {
559 		ret = -EPROBE_DEFER;
560 		DRM_DEV_DEBUG_DRIVER(dev,
561 				     "failed to find bridge for companion bridge: %d\n",
562 				     ret);
563 		goto out;
564 	}
565 
566 	DRM_DEV_DEBUG_DRIVER(dev,
567 			     "dual-link configuration detected (companion bridge %pOF)\n",
568 			     companion);
569 
570 	companion_ldb_ch = bridge_to_ldb_ch(imx8qxp_ldb->companion);
571 	companion_ldb_ch->link_type = ldb_ch->link_type;
572 out:
573 	of_node_put(companion_port);
574 	of_node_put(companion);
575 	return ret;
576 }
577 
imx8qxp_ldb_probe(struct platform_device * pdev)578 static int imx8qxp_ldb_probe(struct platform_device *pdev)
579 {
580 	struct device *dev = &pdev->dev;
581 	struct imx8qxp_ldb *imx8qxp_ldb;
582 	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch;
583 	struct ldb *ldb;
584 	struct ldb_channel *ldb_ch;
585 	int ret, i;
586 
587 	imx8qxp_ldb = devm_kzalloc(dev, sizeof(*imx8qxp_ldb), GFP_KERNEL);
588 	if (!imx8qxp_ldb)
589 		return -ENOMEM;
590 
591 	imx8qxp_ldb->clk_pixel = devm_clk_get(dev, "pixel");
592 	if (IS_ERR(imx8qxp_ldb->clk_pixel)) {
593 		ret = PTR_ERR(imx8qxp_ldb->clk_pixel);
594 		if (ret != -EPROBE_DEFER)
595 			DRM_DEV_ERROR(dev,
596 				      "failed to get pixel clock: %d\n", ret);
597 		return ret;
598 	}
599 
600 	imx8qxp_ldb->clk_bypass = devm_clk_get(dev, "bypass");
601 	if (IS_ERR(imx8qxp_ldb->clk_bypass)) {
602 		ret = PTR_ERR(imx8qxp_ldb->clk_bypass);
603 		if (ret != -EPROBE_DEFER)
604 			DRM_DEV_ERROR(dev,
605 				      "failed to get bypass clock: %d\n", ret);
606 		return ret;
607 	}
608 
609 	imx8qxp_ldb->dev = dev;
610 
611 	ldb = &imx8qxp_ldb->base;
612 	ldb->dev = dev;
613 	ldb->ctrl_reg = 0xe0;
614 
615 	for (i = 0; i < MAX_LDB_CHAN_NUM; i++)
616 		ldb->channel[i] = &imx8qxp_ldb->channel[i].base;
617 
618 	ret = ldb_init_helper(ldb);
619 	if (ret)
620 		return ret;
621 
622 	if (ldb->available_ch_cnt == 0) {
623 		DRM_DEV_DEBUG_DRIVER(dev, "no available channel\n");
624 		return 0;
625 	} else if (ldb->available_ch_cnt > 1) {
626 		DRM_DEV_ERROR(dev, "invalid available channel number(%u)\n",
627 			      ldb->available_ch_cnt);
628 		return -EINVAL;
629 	}
630 
631 	for (i = 0; i < MAX_LDB_CHAN_NUM; i++) {
632 		imx8qxp_ldb_ch = &imx8qxp_ldb->channel[i];
633 		ldb_ch = &imx8qxp_ldb_ch->base;
634 
635 		if (ldb_ch->is_available) {
636 			imx8qxp_ldb->active_chno = ldb_ch->chno;
637 			break;
638 		}
639 	}
640 
641 	imx8qxp_ldb_ch->phy = devm_of_phy_get(dev, ldb_ch->np, "lvds_phy");
642 	if (IS_ERR(imx8qxp_ldb_ch->phy)) {
643 		ret = PTR_ERR(imx8qxp_ldb_ch->phy);
644 		if (ret != -EPROBE_DEFER)
645 			DRM_DEV_ERROR(dev, "failed to get channel%d PHY: %d\n",
646 				      imx8qxp_ldb->active_chno, ret);
647 		return ret;
648 	}
649 
650 	ret = ldb_find_next_bridge_helper(ldb);
651 	if (ret)
652 		return ret;
653 
654 	ret = imx8qxp_ldb_set_di_id(imx8qxp_ldb);
655 	if (ret)
656 		return ret;
657 
658 	ret = imx8qxp_ldb_parse_dt_companion(imx8qxp_ldb);
659 	if (ret)
660 		return ret;
661 
662 	platform_set_drvdata(pdev, imx8qxp_ldb);
663 	pm_runtime_enable(dev);
664 
665 	ldb_add_bridge_helper(ldb, &imx8qxp_ldb_bridge_funcs);
666 
667 	return ret;
668 }
669 
imx8qxp_ldb_remove(struct platform_device * pdev)670 static int imx8qxp_ldb_remove(struct platform_device *pdev)
671 {
672 	struct imx8qxp_ldb *imx8qxp_ldb = platform_get_drvdata(pdev);
673 	struct ldb *ldb = &imx8qxp_ldb->base;
674 
675 	ldb_remove_bridge_helper(ldb);
676 
677 	pm_runtime_disable(&pdev->dev);
678 
679 	return 0;
680 }
681 
imx8qxp_ldb_runtime_suspend(struct device * dev)682 static int __maybe_unused imx8qxp_ldb_runtime_suspend(struct device *dev)
683 {
684 	return 0;
685 }
686 
imx8qxp_ldb_runtime_resume(struct device * dev)687 static int __maybe_unused imx8qxp_ldb_runtime_resume(struct device *dev)
688 {
689 	struct imx8qxp_ldb *imx8qxp_ldb = dev_get_drvdata(dev);
690 	struct ldb *ldb = &imx8qxp_ldb->base;
691 
692 	/* disable LDB by resetting the control register to POR default */
693 	regmap_write(ldb->regmap, ldb->ctrl_reg, 0);
694 
695 	return 0;
696 }
697 
698 static const struct dev_pm_ops imx8qxp_ldb_pm_ops = {
699 	SET_RUNTIME_PM_OPS(imx8qxp_ldb_runtime_suspend,
700 			   imx8qxp_ldb_runtime_resume, NULL)
701 };
702 
703 static const struct of_device_id imx8qxp_ldb_dt_ids[] = {
704 	{ .compatible = "fsl,imx8qxp-ldb" },
705 	{ /* sentinel */ }
706 };
707 MODULE_DEVICE_TABLE(of, imx8qxp_ldb_dt_ids);
708 
709 static struct platform_driver imx8qxp_ldb_driver = {
710 	.probe	= imx8qxp_ldb_probe,
711 	.remove = imx8qxp_ldb_remove,
712 	.driver	= {
713 		.pm = &imx8qxp_ldb_pm_ops,
714 		.name = DRIVER_NAME,
715 		.of_match_table = imx8qxp_ldb_dt_ids,
716 	},
717 };
718 module_platform_driver(imx8qxp_ldb_driver);
719 
720 MODULE_DESCRIPTION("i.MX8QXP LVDS Display Bridge(LDB)/Pixel Mapper bridge driver");
721 MODULE_AUTHOR("Liu Ying <victor.liu@nxp.com>");
722 MODULE_LICENSE("GPL v2");
723 MODULE_ALIAS("platform:" DRIVER_NAME);
724