1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * TI SN65DSI83,84,85 driver
4  *
5  * Currently supported:
6  * - SN65DSI83
7  *   = 1x Single-link DSI ~ 1x Single-link LVDS
8  *   - Supported
9  *   - Single-link LVDS mode tested
10  * - SN65DSI84
11  *   = 1x Single-link DSI ~ 2x Single-link or 1x Dual-link LVDS
12  *   - Supported
13  *   - Dual-link LVDS mode tested
14  *   - 2x Single-link LVDS mode unsupported
15  *     (should be easy to add by someone who has the HW)
16  * - SN65DSI85
17  *   = 2x Single-link or 1x Dual-link DSI ~ 2x Single-link or 1x Dual-link LVDS
18  *   - Unsupported
19  *     (should be easy to add by someone who has the HW)
20  *
21  * Copyright (C) 2021 Marek Vasut <marex@denx.de>
22  *
23  * Based on previous work of:
24  * Valentin Raevsky <valentin@compulab.co.il>
25  * Philippe Schenker <philippe.schenker@toradex.com>
26  */
27 
28 #include <linux/bits.h>
29 #include <linux/clk.h>
30 #include <linux/gpio/consumer.h>
31 #include <linux/i2c.h>
32 #include <linux/module.h>
33 #include <linux/of_device.h>
34 #include <linux/of_graph.h>
35 #include <linux/regmap.h>
36 
37 #include <drm/drm_atomic_helper.h>
38 #include <drm/drm_bridge.h>
39 #include <drm/drm_mipi_dsi.h>
40 #include <drm/drm_of.h>
41 #include <drm/drm_panel.h>
42 #include <drm/drm_print.h>
43 #include <drm/drm_probe_helper.h>
44 
45 /* ID registers */
46 #define REG_ID(n)				(0x00 + (n))
47 /* Reset and clock registers */
48 #define REG_RC_RESET				0x09
49 #define  REG_RC_RESET_SOFT_RESET		BIT(0)
50 #define REG_RC_LVDS_PLL				0x0a
51 #define  REG_RC_LVDS_PLL_PLL_EN_STAT		BIT(7)
52 #define  REG_RC_LVDS_PLL_LVDS_CLK_RANGE(n)	(((n) & 0x7) << 1)
53 #define  REG_RC_LVDS_PLL_HS_CLK_SRC_DPHY	BIT(0)
54 #define REG_RC_DSI_CLK				0x0b
55 #define  REG_RC_DSI_CLK_DSI_CLK_DIVIDER(n)	(((n) & 0x1f) << 3)
56 #define  REG_RC_DSI_CLK_REFCLK_MULTIPLIER(n)	((n) & 0x3)
57 #define REG_RC_PLL_EN				0x0d
58 #define  REG_RC_PLL_EN_PLL_EN			BIT(0)
59 /* DSI registers */
60 #define REG_DSI_LANE				0x10
61 #define  REG_DSI_LANE_LEFT_RIGHT_PIXELS		BIT(7)	/* DSI85-only */
62 #define  REG_DSI_LANE_DSI_CHANNEL_MODE_DUAL	0	/* DSI85-only */
63 #define  REG_DSI_LANE_DSI_CHANNEL_MODE_2SINGLE	BIT(6)	/* DSI85-only */
64 #define  REG_DSI_LANE_DSI_CHANNEL_MODE_SINGLE	BIT(5)
65 #define  REG_DSI_LANE_CHA_DSI_LANES(n)		(((n) & 0x3) << 3)
66 #define  REG_DSI_LANE_CHB_DSI_LANES(n)		(((n) & 0x3) << 1)
67 #define  REG_DSI_LANE_SOT_ERR_TOL_DIS		BIT(0)
68 #define REG_DSI_EQ				0x11
69 #define  REG_DSI_EQ_CHA_DSI_DATA_EQ(n)		(((n) & 0x3) << 6)
70 #define  REG_DSI_EQ_CHA_DSI_CLK_EQ(n)		(((n) & 0x3) << 2)
71 #define REG_DSI_CLK				0x12
72 #define  REG_DSI_CLK_CHA_DSI_CLK_RANGE(n)	((n) & 0xff)
73 /* LVDS registers */
74 #define REG_LVDS_FMT				0x18
75 #define  REG_LVDS_FMT_DE_NEG_POLARITY		BIT(7)
76 #define  REG_LVDS_FMT_HS_NEG_POLARITY		BIT(6)
77 #define  REG_LVDS_FMT_VS_NEG_POLARITY		BIT(5)
78 #define  REG_LVDS_FMT_LVDS_LINK_CFG		BIT(4)	/* 0:AB 1:A-only */
79 #define  REG_LVDS_FMT_CHA_24BPP_MODE		BIT(3)
80 #define  REG_LVDS_FMT_CHB_24BPP_MODE		BIT(2)
81 #define  REG_LVDS_FMT_CHA_24BPP_FORMAT1		BIT(1)
82 #define  REG_LVDS_FMT_CHB_24BPP_FORMAT1		BIT(0)
83 #define REG_LVDS_VCOM				0x19
84 #define  REG_LVDS_VCOM_CHA_LVDS_VOCM		BIT(6)
85 #define  REG_LVDS_VCOM_CHB_LVDS_VOCM		BIT(4)
86 #define  REG_LVDS_VCOM_CHA_LVDS_VOD_SWING(n)	(((n) & 0x3) << 2)
87 #define  REG_LVDS_VCOM_CHB_LVDS_VOD_SWING(n)	((n) & 0x3)
88 #define REG_LVDS_LANE				0x1a
89 #define  REG_LVDS_LANE_EVEN_ODD_SWAP		BIT(6)
90 #define  REG_LVDS_LANE_CHA_REVERSE_LVDS		BIT(5)
91 #define  REG_LVDS_LANE_CHB_REVERSE_LVDS		BIT(4)
92 #define  REG_LVDS_LANE_CHA_LVDS_TERM		BIT(1)
93 #define  REG_LVDS_LANE_CHB_LVDS_TERM		BIT(0)
94 #define REG_LVDS_CM				0x1b
95 #define  REG_LVDS_CM_CHA_LVDS_CM_ADJUST(n)	(((n) & 0x3) << 4)
96 #define  REG_LVDS_CM_CHB_LVDS_CM_ADJUST(n)	((n) & 0x3)
97 /* Video registers */
98 #define REG_VID_CHA_ACTIVE_LINE_LENGTH_LOW	0x20
99 #define REG_VID_CHA_ACTIVE_LINE_LENGTH_HIGH	0x21
100 #define REG_VID_CHA_VERTICAL_DISPLAY_SIZE_LOW	0x24
101 #define REG_VID_CHA_VERTICAL_DISPLAY_SIZE_HIGH	0x25
102 #define REG_VID_CHA_SYNC_DELAY_LOW		0x28
103 #define REG_VID_CHA_SYNC_DELAY_HIGH		0x29
104 #define REG_VID_CHA_HSYNC_PULSE_WIDTH_LOW	0x2c
105 #define REG_VID_CHA_HSYNC_PULSE_WIDTH_HIGH	0x2d
106 #define REG_VID_CHA_VSYNC_PULSE_WIDTH_LOW	0x30
107 #define REG_VID_CHA_VSYNC_PULSE_WIDTH_HIGH	0x31
108 #define REG_VID_CHA_HORIZONTAL_BACK_PORCH	0x34
109 #define REG_VID_CHA_VERTICAL_BACK_PORCH		0x36
110 #define REG_VID_CHA_HORIZONTAL_FRONT_PORCH	0x38
111 #define REG_VID_CHA_VERTICAL_FRONT_PORCH	0x3a
112 #define REG_VID_CHA_TEST_PATTERN		0x3c
113 /* IRQ registers */
114 #define REG_IRQ_GLOBAL				0xe0
115 #define  REG_IRQ_GLOBAL_IRQ_EN			BIT(0)
116 #define REG_IRQ_EN				0xe1
117 #define  REG_IRQ_EN_CHA_SYNCH_ERR_EN		BIT(7)
118 #define  REG_IRQ_EN_CHA_CRC_ERR_EN		BIT(6)
119 #define  REG_IRQ_EN_CHA_UNC_ECC_ERR_EN		BIT(5)
120 #define  REG_IRQ_EN_CHA_COR_ECC_ERR_EN		BIT(4)
121 #define  REG_IRQ_EN_CHA_LLP_ERR_EN		BIT(3)
122 #define  REG_IRQ_EN_CHA_SOT_BIT_ERR_EN		BIT(2)
123 #define  REG_IRQ_EN_CHA_PLL_UNLOCK_EN		BIT(0)
124 #define REG_IRQ_STAT				0xe5
125 #define  REG_IRQ_STAT_CHA_SYNCH_ERR		BIT(7)
126 #define  REG_IRQ_STAT_CHA_CRC_ERR		BIT(6)
127 #define  REG_IRQ_STAT_CHA_UNC_ECC_ERR		BIT(5)
128 #define  REG_IRQ_STAT_CHA_COR_ECC_ERR		BIT(4)
129 #define  REG_IRQ_STAT_CHA_LLP_ERR		BIT(3)
130 #define  REG_IRQ_STAT_CHA_SOT_BIT_ERR		BIT(2)
131 #define  REG_IRQ_STAT_CHA_PLL_UNLOCK		BIT(0)
132 
133 enum sn65dsi83_model {
134 	MODEL_SN65DSI83,
135 	MODEL_SN65DSI84,
136 };
137 
138 struct sn65dsi83 {
139 	struct drm_bridge		bridge;
140 	struct device			*dev;
141 	struct regmap			*regmap;
142 	struct device_node		*host_node;
143 	struct mipi_dsi_device		*dsi;
144 	struct drm_bridge		*panel_bridge;
145 	struct gpio_desc		*enable_gpio;
146 	int				dsi_lanes;
147 	bool				lvds_dual_link;
148 	bool				lvds_dual_link_even_odd_swap;
149 };
150 
151 static const struct regmap_range sn65dsi83_readable_ranges[] = {
152 	regmap_reg_range(REG_ID(0), REG_ID(8)),
153 	regmap_reg_range(REG_RC_LVDS_PLL, REG_RC_DSI_CLK),
154 	regmap_reg_range(REG_RC_PLL_EN, REG_RC_PLL_EN),
155 	regmap_reg_range(REG_DSI_LANE, REG_DSI_CLK),
156 	regmap_reg_range(REG_LVDS_FMT, REG_LVDS_CM),
157 	regmap_reg_range(REG_VID_CHA_ACTIVE_LINE_LENGTH_LOW,
158 			 REG_VID_CHA_ACTIVE_LINE_LENGTH_HIGH),
159 	regmap_reg_range(REG_VID_CHA_VERTICAL_DISPLAY_SIZE_LOW,
160 			 REG_VID_CHA_VERTICAL_DISPLAY_SIZE_HIGH),
161 	regmap_reg_range(REG_VID_CHA_SYNC_DELAY_LOW,
162 			 REG_VID_CHA_SYNC_DELAY_HIGH),
163 	regmap_reg_range(REG_VID_CHA_HSYNC_PULSE_WIDTH_LOW,
164 			 REG_VID_CHA_HSYNC_PULSE_WIDTH_HIGH),
165 	regmap_reg_range(REG_VID_CHA_VSYNC_PULSE_WIDTH_LOW,
166 			 REG_VID_CHA_VSYNC_PULSE_WIDTH_HIGH),
167 	regmap_reg_range(REG_VID_CHA_HORIZONTAL_BACK_PORCH,
168 			 REG_VID_CHA_HORIZONTAL_BACK_PORCH),
169 	regmap_reg_range(REG_VID_CHA_VERTICAL_BACK_PORCH,
170 			 REG_VID_CHA_VERTICAL_BACK_PORCH),
171 	regmap_reg_range(REG_VID_CHA_HORIZONTAL_FRONT_PORCH,
172 			 REG_VID_CHA_HORIZONTAL_FRONT_PORCH),
173 	regmap_reg_range(REG_VID_CHA_VERTICAL_FRONT_PORCH,
174 			 REG_VID_CHA_VERTICAL_FRONT_PORCH),
175 	regmap_reg_range(REG_VID_CHA_TEST_PATTERN, REG_VID_CHA_TEST_PATTERN),
176 	regmap_reg_range(REG_IRQ_GLOBAL, REG_IRQ_EN),
177 	regmap_reg_range(REG_IRQ_STAT, REG_IRQ_STAT),
178 };
179 
180 static const struct regmap_access_table sn65dsi83_readable_table = {
181 	.yes_ranges = sn65dsi83_readable_ranges,
182 	.n_yes_ranges = ARRAY_SIZE(sn65dsi83_readable_ranges),
183 };
184 
185 static const struct regmap_range sn65dsi83_writeable_ranges[] = {
186 	regmap_reg_range(REG_RC_RESET, REG_RC_DSI_CLK),
187 	regmap_reg_range(REG_RC_PLL_EN, REG_RC_PLL_EN),
188 	regmap_reg_range(REG_DSI_LANE, REG_DSI_CLK),
189 	regmap_reg_range(REG_LVDS_FMT, REG_LVDS_CM),
190 	regmap_reg_range(REG_VID_CHA_ACTIVE_LINE_LENGTH_LOW,
191 			 REG_VID_CHA_ACTIVE_LINE_LENGTH_HIGH),
192 	regmap_reg_range(REG_VID_CHA_VERTICAL_DISPLAY_SIZE_LOW,
193 			 REG_VID_CHA_VERTICAL_DISPLAY_SIZE_HIGH),
194 	regmap_reg_range(REG_VID_CHA_SYNC_DELAY_LOW,
195 			 REG_VID_CHA_SYNC_DELAY_HIGH),
196 	regmap_reg_range(REG_VID_CHA_HSYNC_PULSE_WIDTH_LOW,
197 			 REG_VID_CHA_HSYNC_PULSE_WIDTH_HIGH),
198 	regmap_reg_range(REG_VID_CHA_VSYNC_PULSE_WIDTH_LOW,
199 			 REG_VID_CHA_VSYNC_PULSE_WIDTH_HIGH),
200 	regmap_reg_range(REG_VID_CHA_HORIZONTAL_BACK_PORCH,
201 			 REG_VID_CHA_HORIZONTAL_BACK_PORCH),
202 	regmap_reg_range(REG_VID_CHA_VERTICAL_BACK_PORCH,
203 			 REG_VID_CHA_VERTICAL_BACK_PORCH),
204 	regmap_reg_range(REG_VID_CHA_HORIZONTAL_FRONT_PORCH,
205 			 REG_VID_CHA_HORIZONTAL_FRONT_PORCH),
206 	regmap_reg_range(REG_VID_CHA_VERTICAL_FRONT_PORCH,
207 			 REG_VID_CHA_VERTICAL_FRONT_PORCH),
208 	regmap_reg_range(REG_VID_CHA_TEST_PATTERN, REG_VID_CHA_TEST_PATTERN),
209 	regmap_reg_range(REG_IRQ_GLOBAL, REG_IRQ_EN),
210 	regmap_reg_range(REG_IRQ_STAT, REG_IRQ_STAT),
211 };
212 
213 static const struct regmap_access_table sn65dsi83_writeable_table = {
214 	.yes_ranges = sn65dsi83_writeable_ranges,
215 	.n_yes_ranges = ARRAY_SIZE(sn65dsi83_writeable_ranges),
216 };
217 
218 static const struct regmap_range sn65dsi83_volatile_ranges[] = {
219 	regmap_reg_range(REG_RC_RESET, REG_RC_RESET),
220 	regmap_reg_range(REG_RC_LVDS_PLL, REG_RC_LVDS_PLL),
221 	regmap_reg_range(REG_IRQ_STAT, REG_IRQ_STAT),
222 };
223 
224 static const struct regmap_access_table sn65dsi83_volatile_table = {
225 	.yes_ranges = sn65dsi83_volatile_ranges,
226 	.n_yes_ranges = ARRAY_SIZE(sn65dsi83_volatile_ranges),
227 };
228 
229 static const struct regmap_config sn65dsi83_regmap_config = {
230 	.reg_bits = 8,
231 	.val_bits = 8,
232 	.rd_table = &sn65dsi83_readable_table,
233 	.wr_table = &sn65dsi83_writeable_table,
234 	.volatile_table = &sn65dsi83_volatile_table,
235 	.cache_type = REGCACHE_RBTREE,
236 	.max_register = REG_IRQ_STAT,
237 };
238 
239 static struct sn65dsi83 *bridge_to_sn65dsi83(struct drm_bridge *bridge)
240 {
241 	return container_of(bridge, struct sn65dsi83, bridge);
242 }
243 
244 static int sn65dsi83_attach(struct drm_bridge *bridge,
245 			    enum drm_bridge_attach_flags flags)
246 {
247 	struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
248 	struct device *dev = ctx->dev;
249 	struct mipi_dsi_device *dsi;
250 	struct mipi_dsi_host *host;
251 	int ret = 0;
252 
253 	const struct mipi_dsi_device_info info = {
254 		.type = "sn65dsi83",
255 		.channel = 0,
256 		.node = NULL,
257 	};
258 
259 	host = of_find_mipi_dsi_host_by_node(ctx->host_node);
260 	if (!host) {
261 		dev_err(dev, "failed to find dsi host\n");
262 		return -EPROBE_DEFER;
263 	}
264 
265 	dsi = mipi_dsi_device_register_full(host, &info);
266 	if (IS_ERR(dsi)) {
267 		return dev_err_probe(dev, PTR_ERR(dsi),
268 				     "failed to create dsi device\n");
269 	}
270 
271 	ctx->dsi = dsi;
272 
273 	dsi->lanes = ctx->dsi_lanes;
274 	dsi->format = MIPI_DSI_FMT_RGB888;
275 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST;
276 
277 	ret = mipi_dsi_attach(dsi);
278 	if (ret < 0) {
279 		dev_err(dev, "failed to attach dsi to host\n");
280 		goto err_dsi_attach;
281 	}
282 
283 	return drm_bridge_attach(bridge->encoder, ctx->panel_bridge,
284 				 &ctx->bridge, flags);
285 
286 err_dsi_attach:
287 	mipi_dsi_device_unregister(dsi);
288 	return ret;
289 }
290 
291 static void sn65dsi83_detach(struct drm_bridge *bridge)
292 {
293 	struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
294 
295 	if (!ctx->dsi)
296 		return;
297 
298 	mipi_dsi_detach(ctx->dsi);
299 	mipi_dsi_device_unregister(ctx->dsi);
300 	drm_bridge_remove(&ctx->bridge);
301 	ctx->dsi = NULL;
302 }
303 
304 static void sn65dsi83_atomic_pre_enable(struct drm_bridge *bridge,
305 					struct drm_bridge_state *old_bridge_state)
306 {
307 	struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
308 
309 	/*
310 	 * Reset the chip, pull EN line low for t_reset=10ms,
311 	 * then high for t_en=1ms.
312 	 */
313 	regcache_mark_dirty(ctx->regmap);
314 	gpiod_set_value(ctx->enable_gpio, 0);
315 	usleep_range(10000, 11000);
316 	gpiod_set_value(ctx->enable_gpio, 1);
317 	usleep_range(1000, 1100);
318 }
319 
320 static u8 sn65dsi83_get_lvds_range(struct sn65dsi83 *ctx,
321 				   const struct drm_display_mode *mode)
322 {
323 	/*
324 	 * The encoding of the LVDS_CLK_RANGE is as follows:
325 	 * 000 - 25 MHz <= LVDS_CLK < 37.5 MHz
326 	 * 001 - 37.5 MHz <= LVDS_CLK < 62.5 MHz
327 	 * 010 - 62.5 MHz <= LVDS_CLK < 87.5 MHz
328 	 * 011 - 87.5 MHz <= LVDS_CLK < 112.5 MHz
329 	 * 100 - 112.5 MHz <= LVDS_CLK < 137.5 MHz
330 	 * 101 - 137.5 MHz <= LVDS_CLK <= 154 MHz
331 	 * which is a range of 12.5MHz..162.5MHz in 50MHz steps, except that
332 	 * the ends of the ranges are clamped to the supported range. Since
333 	 * sn65dsi83_mode_valid() already filters the valid modes and limits
334 	 * the clock to 25..154 MHz, the range calculation can be simplified
335 	 * as follows:
336 	 */
337 	int mode_clock = mode->clock;
338 
339 	if (ctx->lvds_dual_link)
340 		mode_clock /= 2;
341 
342 	return (mode_clock - 12500) / 25000;
343 }
344 
345 static u8 sn65dsi83_get_dsi_range(struct sn65dsi83 *ctx,
346 				  const struct drm_display_mode *mode)
347 {
348 	/*
349 	 * The encoding of the CHA_DSI_CLK_RANGE is as follows:
350 	 * 0x00 through 0x07 - Reserved
351 	 * 0x08 - 40 <= DSI_CLK < 45 MHz
352 	 * 0x09 - 45 <= DSI_CLK < 50 MHz
353 	 * ...
354 	 * 0x63 - 495 <= DSI_CLK < 500 MHz
355 	 * 0x64 - 500 MHz
356 	 * 0x65 through 0xFF - Reserved
357 	 * which is DSI clock in 5 MHz steps, clamped to 40..500 MHz.
358 	 * The DSI clock are calculated as:
359 	 *  DSI_CLK = mode clock * bpp / dsi_data_lanes / 2
360 	 * the 2 is there because the bus is DDR.
361 	 */
362 	return DIV_ROUND_UP(clamp((unsigned int)mode->clock *
363 			    mipi_dsi_pixel_format_to_bpp(ctx->dsi->format) /
364 			    ctx->dsi_lanes / 2, 40000U, 500000U), 5000U);
365 }
366 
367 static u8 sn65dsi83_get_dsi_div(struct sn65dsi83 *ctx)
368 {
369 	/* The divider is (DSI_CLK / LVDS_CLK) - 1, which really is: */
370 	unsigned int dsi_div = mipi_dsi_pixel_format_to_bpp(ctx->dsi->format);
371 
372 	dsi_div /= ctx->dsi_lanes;
373 
374 	if (!ctx->lvds_dual_link)
375 		dsi_div /= 2;
376 
377 	return dsi_div - 1;
378 }
379 
380 static void sn65dsi83_atomic_enable(struct drm_bridge *bridge,
381 				    struct drm_bridge_state *old_bridge_state)
382 {
383 	struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
384 	struct drm_atomic_state *state = old_bridge_state->base.state;
385 	const struct drm_bridge_state *bridge_state;
386 	const struct drm_crtc_state *crtc_state;
387 	const struct drm_display_mode *mode;
388 	struct drm_connector *connector;
389 	struct drm_crtc *crtc;
390 	bool lvds_format_24bpp;
391 	bool lvds_format_jeida;
392 	unsigned int pval;
393 	__le16 le16val;
394 	u16 val;
395 	int ret;
396 
397 	/* Get the LVDS format from the bridge state. */
398 	bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
399 
400 	switch (bridge_state->output_bus_cfg.format) {
401 	case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
402 		lvds_format_24bpp = false;
403 		lvds_format_jeida = true;
404 		break;
405 	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
406 		lvds_format_24bpp = true;
407 		lvds_format_jeida = true;
408 		break;
409 	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
410 		lvds_format_24bpp = true;
411 		lvds_format_jeida = false;
412 		break;
413 	default:
414 		/*
415 		 * Some bridges still don't set the correct
416 		 * LVDS bus pixel format, use SPWG24 default
417 		 * format until those are fixed.
418 		 */
419 		lvds_format_24bpp = true;
420 		lvds_format_jeida = false;
421 		dev_warn(ctx->dev,
422 			 "Unsupported LVDS bus format 0x%04x, please check output bridge driver. Falling back to SPWG24.\n",
423 			 bridge_state->output_bus_cfg.format);
424 		break;
425 	}
426 
427 	/*
428 	 * Retrieve the CRTC adjusted mode. This requires a little dance to go
429 	 * from the bridge to the encoder, to the connector and to the CRTC.
430 	 */
431 	connector = drm_atomic_get_new_connector_for_encoder(state,
432 							     bridge->encoder);
433 	crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
434 	crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
435 	mode = &crtc_state->adjusted_mode;
436 
437 	/* Clear reset, disable PLL */
438 	regmap_write(ctx->regmap, REG_RC_RESET, 0x00);
439 	regmap_write(ctx->regmap, REG_RC_PLL_EN, 0x00);
440 
441 	/* Reference clock derived from DSI link clock. */
442 	regmap_write(ctx->regmap, REG_RC_LVDS_PLL,
443 		     REG_RC_LVDS_PLL_LVDS_CLK_RANGE(sn65dsi83_get_lvds_range(ctx, mode)) |
444 		     REG_RC_LVDS_PLL_HS_CLK_SRC_DPHY);
445 	regmap_write(ctx->regmap, REG_DSI_CLK,
446 		     REG_DSI_CLK_CHA_DSI_CLK_RANGE(sn65dsi83_get_dsi_range(ctx, mode)));
447 	regmap_write(ctx->regmap, REG_RC_DSI_CLK,
448 		     REG_RC_DSI_CLK_DSI_CLK_DIVIDER(sn65dsi83_get_dsi_div(ctx)));
449 
450 	/* Set number of DSI lanes and LVDS link config. */
451 	regmap_write(ctx->regmap, REG_DSI_LANE,
452 		     REG_DSI_LANE_DSI_CHANNEL_MODE_SINGLE |
453 		     REG_DSI_LANE_CHA_DSI_LANES(~(ctx->dsi_lanes - 1)) |
454 		     /* CHB is DSI85-only, set to default on DSI83/DSI84 */
455 		     REG_DSI_LANE_CHB_DSI_LANES(3));
456 	/* No equalization. */
457 	regmap_write(ctx->regmap, REG_DSI_EQ, 0x00);
458 
459 	/* Set up sync signal polarity. */
460 	val = (mode->flags & DRM_MODE_FLAG_NHSYNC ?
461 	       REG_LVDS_FMT_HS_NEG_POLARITY : 0) |
462 	      (mode->flags & DRM_MODE_FLAG_NVSYNC ?
463 	       REG_LVDS_FMT_VS_NEG_POLARITY : 0);
464 
465 	/* Set up bits-per-pixel, 18bpp or 24bpp. */
466 	if (lvds_format_24bpp) {
467 		val |= REG_LVDS_FMT_CHA_24BPP_MODE;
468 		if (ctx->lvds_dual_link)
469 			val |= REG_LVDS_FMT_CHB_24BPP_MODE;
470 	}
471 
472 	/* Set up LVDS format, JEIDA/Format 1 or SPWG/Format 2 */
473 	if (lvds_format_jeida) {
474 		val |= REG_LVDS_FMT_CHA_24BPP_FORMAT1;
475 		if (ctx->lvds_dual_link)
476 			val |= REG_LVDS_FMT_CHB_24BPP_FORMAT1;
477 	}
478 
479 	/* Set up LVDS output config (DSI84,DSI85) */
480 	if (!ctx->lvds_dual_link)
481 		val |= REG_LVDS_FMT_LVDS_LINK_CFG;
482 
483 	regmap_write(ctx->regmap, REG_LVDS_FMT, val);
484 	regmap_write(ctx->regmap, REG_LVDS_VCOM, 0x05);
485 	regmap_write(ctx->regmap, REG_LVDS_LANE,
486 		     (ctx->lvds_dual_link_even_odd_swap ?
487 		      REG_LVDS_LANE_EVEN_ODD_SWAP : 0) |
488 		     REG_LVDS_LANE_CHA_LVDS_TERM |
489 		     REG_LVDS_LANE_CHB_LVDS_TERM);
490 	regmap_write(ctx->regmap, REG_LVDS_CM, 0x00);
491 
492 	le16val = cpu_to_le16(mode->hdisplay);
493 	regmap_bulk_write(ctx->regmap, REG_VID_CHA_ACTIVE_LINE_LENGTH_LOW,
494 			  &le16val, 2);
495 	le16val = cpu_to_le16(mode->vdisplay);
496 	regmap_bulk_write(ctx->regmap, REG_VID_CHA_VERTICAL_DISPLAY_SIZE_LOW,
497 			  &le16val, 2);
498 	/* 32 + 1 pixel clock to ensure proper operation */
499 	le16val = cpu_to_le16(32 + 1);
500 	regmap_bulk_write(ctx->regmap, REG_VID_CHA_SYNC_DELAY_LOW, &le16val, 2);
501 	le16val = cpu_to_le16(mode->hsync_end - mode->hsync_start);
502 	regmap_bulk_write(ctx->regmap, REG_VID_CHA_HSYNC_PULSE_WIDTH_LOW,
503 			  &le16val, 2);
504 	le16val = cpu_to_le16(mode->vsync_end - mode->vsync_start);
505 	regmap_bulk_write(ctx->regmap, REG_VID_CHA_VSYNC_PULSE_WIDTH_LOW,
506 			  &le16val, 2);
507 	regmap_write(ctx->regmap, REG_VID_CHA_HORIZONTAL_BACK_PORCH,
508 		     mode->htotal - mode->hsync_end);
509 	regmap_write(ctx->regmap, REG_VID_CHA_VERTICAL_BACK_PORCH,
510 		     mode->vtotal - mode->vsync_end);
511 	regmap_write(ctx->regmap, REG_VID_CHA_HORIZONTAL_FRONT_PORCH,
512 		     mode->hsync_start - mode->hdisplay);
513 	regmap_write(ctx->regmap, REG_VID_CHA_VERTICAL_FRONT_PORCH,
514 		     mode->vsync_start - mode->vdisplay);
515 	regmap_write(ctx->regmap, REG_VID_CHA_TEST_PATTERN, 0x00);
516 
517 	/* Enable PLL */
518 	regmap_write(ctx->regmap, REG_RC_PLL_EN, REG_RC_PLL_EN_PLL_EN);
519 	usleep_range(3000, 4000);
520 	ret = regmap_read_poll_timeout(ctx->regmap, REG_RC_LVDS_PLL, pval,
521 				       pval & REG_RC_LVDS_PLL_PLL_EN_STAT,
522 				       1000, 100000);
523 	if (ret) {
524 		dev_err(ctx->dev, "failed to lock PLL, ret=%i\n", ret);
525 		/* On failure, disable PLL again and exit. */
526 		regmap_write(ctx->regmap, REG_RC_PLL_EN, 0x00);
527 		return;
528 	}
529 
530 	/* Trigger reset after CSR register update. */
531 	regmap_write(ctx->regmap, REG_RC_RESET, REG_RC_RESET_SOFT_RESET);
532 
533 	/* Clear all errors that got asserted during initialization. */
534 	regmap_read(ctx->regmap, REG_IRQ_STAT, &pval);
535 	regmap_write(ctx->regmap, REG_IRQ_STAT, pval);
536 }
537 
538 static void sn65dsi83_atomic_disable(struct drm_bridge *bridge,
539 				     struct drm_bridge_state *old_bridge_state)
540 {
541 	struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
542 
543 	/* Clear reset, disable PLL */
544 	regmap_write(ctx->regmap, REG_RC_RESET, 0x00);
545 	regmap_write(ctx->regmap, REG_RC_PLL_EN, 0x00);
546 }
547 
548 static void sn65dsi83_atomic_post_disable(struct drm_bridge *bridge,
549 					  struct drm_bridge_state *old_bridge_state)
550 {
551 	struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
552 
553 	/* Put the chip in reset, pull EN line low. */
554 	gpiod_set_value(ctx->enable_gpio, 0);
555 }
556 
557 static enum drm_mode_status
558 sn65dsi83_mode_valid(struct drm_bridge *bridge,
559 		     const struct drm_display_info *info,
560 		     const struct drm_display_mode *mode)
561 {
562 	/* LVDS output clock range 25..154 MHz */
563 	if (mode->clock < 25000)
564 		return MODE_CLOCK_LOW;
565 	if (mode->clock > 154000)
566 		return MODE_CLOCK_HIGH;
567 
568 	return MODE_OK;
569 }
570 
571 #define MAX_INPUT_SEL_FORMATS	1
572 
573 static u32 *
574 sn65dsi83_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
575 				    struct drm_bridge_state *bridge_state,
576 				    struct drm_crtc_state *crtc_state,
577 				    struct drm_connector_state *conn_state,
578 				    u32 output_fmt,
579 				    unsigned int *num_input_fmts)
580 {
581 	u32 *input_fmts;
582 
583 	*num_input_fmts = 0;
584 
585 	input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
586 			     GFP_KERNEL);
587 	if (!input_fmts)
588 		return NULL;
589 
590 	/* This is the DSI-end bus format */
591 	input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
592 	*num_input_fmts = 1;
593 
594 	return input_fmts;
595 }
596 
597 static const struct drm_bridge_funcs sn65dsi83_funcs = {
598 	.attach			= sn65dsi83_attach,
599 	.detach			= sn65dsi83_detach,
600 	.atomic_pre_enable	= sn65dsi83_atomic_pre_enable,
601 	.atomic_enable		= sn65dsi83_atomic_enable,
602 	.atomic_disable		= sn65dsi83_atomic_disable,
603 	.atomic_post_disable	= sn65dsi83_atomic_post_disable,
604 	.mode_valid		= sn65dsi83_mode_valid,
605 
606 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
607 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
608 	.atomic_reset = drm_atomic_helper_bridge_reset,
609 	.atomic_get_input_bus_fmts = sn65dsi83_atomic_get_input_bus_fmts,
610 };
611 
612 static int sn65dsi83_parse_dt(struct sn65dsi83 *ctx, enum sn65dsi83_model model)
613 {
614 	struct drm_bridge *panel_bridge;
615 	struct device *dev = ctx->dev;
616 	struct device_node *endpoint;
617 	struct drm_panel *panel;
618 	int ret;
619 
620 	endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
621 	ctx->dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
622 	ctx->host_node = of_graph_get_remote_port_parent(endpoint);
623 	of_node_put(endpoint);
624 
625 	if (ctx->dsi_lanes < 0 || ctx->dsi_lanes > 4)
626 		return -EINVAL;
627 	if (!ctx->host_node)
628 		return -ENODEV;
629 
630 	ctx->lvds_dual_link = false;
631 	ctx->lvds_dual_link_even_odd_swap = false;
632 	if (model != MODEL_SN65DSI83) {
633 		struct device_node *port2, *port3;
634 		int dual_link;
635 
636 		port2 = of_graph_get_port_by_id(dev->of_node, 2);
637 		port3 = of_graph_get_port_by_id(dev->of_node, 3);
638 		dual_link = drm_of_lvds_get_dual_link_pixel_order(port2, port3);
639 		of_node_put(port2);
640 		of_node_put(port3);
641 
642 		if (dual_link == DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS) {
643 			ctx->lvds_dual_link = true;
644 			/* Odd pixels to LVDS Channel A, even pixels to B */
645 			ctx->lvds_dual_link_even_odd_swap = false;
646 		} else if (dual_link == DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS) {
647 			ctx->lvds_dual_link = true;
648 			/* Even pixels to LVDS Channel A, odd pixels to B */
649 			ctx->lvds_dual_link_even_odd_swap = true;
650 		}
651 	}
652 
653 	ret = drm_of_find_panel_or_bridge(dev->of_node, 2, 0, &panel, &panel_bridge);
654 	if (ret < 0)
655 		return ret;
656 	if (panel) {
657 		panel_bridge = devm_drm_panel_bridge_add(dev, panel);
658 		if (IS_ERR(panel_bridge))
659 			return PTR_ERR(panel_bridge);
660 	}
661 
662 	ctx->panel_bridge = panel_bridge;
663 
664 	return 0;
665 }
666 
667 static int sn65dsi83_probe(struct i2c_client *client,
668 			   const struct i2c_device_id *id)
669 {
670 	struct device *dev = &client->dev;
671 	enum sn65dsi83_model model;
672 	struct sn65dsi83 *ctx;
673 	int ret;
674 
675 	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
676 	if (!ctx)
677 		return -ENOMEM;
678 
679 	ctx->dev = dev;
680 
681 	if (dev->of_node) {
682 		model = (enum sn65dsi83_model)(uintptr_t)
683 			of_device_get_match_data(dev);
684 	} else {
685 		model = id->driver_data;
686 	}
687 
688 	ctx->enable_gpio = devm_gpiod_get(ctx->dev, "enable", GPIOD_OUT_LOW);
689 	if (IS_ERR(ctx->enable_gpio))
690 		return PTR_ERR(ctx->enable_gpio);
691 
692 	ret = sn65dsi83_parse_dt(ctx, model);
693 	if (ret)
694 		return ret;
695 
696 	ctx->regmap = devm_regmap_init_i2c(client, &sn65dsi83_regmap_config);
697 	if (IS_ERR(ctx->regmap))
698 		return PTR_ERR(ctx->regmap);
699 
700 	dev_set_drvdata(dev, ctx);
701 	i2c_set_clientdata(client, ctx);
702 
703 	ctx->bridge.funcs = &sn65dsi83_funcs;
704 	ctx->bridge.of_node = dev->of_node;
705 	drm_bridge_add(&ctx->bridge);
706 
707 	return 0;
708 }
709 
710 static int sn65dsi83_remove(struct i2c_client *client)
711 {
712 	struct sn65dsi83 *ctx = i2c_get_clientdata(client);
713 
714 	of_node_put(ctx->host_node);
715 
716 	return 0;
717 }
718 
719 static struct i2c_device_id sn65dsi83_id[] = {
720 	{ "ti,sn65dsi83", MODEL_SN65DSI83 },
721 	{ "ti,sn65dsi84", MODEL_SN65DSI84 },
722 	{},
723 };
724 MODULE_DEVICE_TABLE(i2c, sn65dsi83_id);
725 
726 static const struct of_device_id sn65dsi83_match_table[] = {
727 	{ .compatible = "ti,sn65dsi83", .data = (void *)MODEL_SN65DSI83 },
728 	{ .compatible = "ti,sn65dsi84", .data = (void *)MODEL_SN65DSI84 },
729 	{},
730 };
731 MODULE_DEVICE_TABLE(of, sn65dsi83_match_table);
732 
733 static struct i2c_driver sn65dsi83_driver = {
734 	.probe = sn65dsi83_probe,
735 	.remove = sn65dsi83_remove,
736 	.id_table = sn65dsi83_id,
737 	.driver = {
738 		.name = "sn65dsi83",
739 		.of_match_table = sn65dsi83_match_table,
740 	},
741 };
742 module_i2c_driver(sn65dsi83_driver);
743 
744 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
745 MODULE_DESCRIPTION("TI SN65DSI83 DSI to LVDS bridge driver");
746 MODULE_LICENSE("GPL v2");
747