xref: /linux/drivers/gpu/drm/bridge/ti-sn65dsi86.c (revision 088e88be5a380cc4e81963a9a02815da465d144f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2018, The Linux Foundation. All rights reserved.
4  */
5 
6 #include <linux/clk.h>
7 #include <linux/gpio/consumer.h>
8 #include <linux/i2c.h>
9 #include <linux/iopoll.h>
10 #include <linux/module.h>
11 #include <linux/of_graph.h>
12 #include <linux/pm_runtime.h>
13 #include <linux/regmap.h>
14 #include <linux/regulator/consumer.h>
15 
16 #include <drm/drm_atomic.h>
17 #include <drm/drm_atomic_helper.h>
18 #include <drm/drm_dp_helper.h>
19 #include <drm/drm_mipi_dsi.h>
20 #include <drm/drm_of.h>
21 #include <drm/drm_panel.h>
22 #include <drm/drm_print.h>
23 #include <drm/drm_probe_helper.h>
24 
25 #define SN_DEVICE_REV_REG			0x08
26 #define SN_DPPLL_SRC_REG			0x0A
27 #define  DPPLL_CLK_SRC_DSICLK			BIT(0)
28 #define  REFCLK_FREQ_MASK			GENMASK(3, 1)
29 #define  REFCLK_FREQ(x)				((x) << 1)
30 #define  DPPLL_SRC_DP_PLL_LOCK			BIT(7)
31 #define SN_PLL_ENABLE_REG			0x0D
32 #define SN_DSI_LANES_REG			0x10
33 #define  CHA_DSI_LANES_MASK			GENMASK(4, 3)
34 #define  CHA_DSI_LANES(x)			((x) << 3)
35 #define SN_DSIA_CLK_FREQ_REG			0x12
36 #define SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG	0x20
37 #define SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG	0x24
38 #define SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG	0x2C
39 #define SN_CHA_HSYNC_PULSE_WIDTH_HIGH_REG	0x2D
40 #define  CHA_HSYNC_POLARITY			BIT(7)
41 #define SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG	0x30
42 #define SN_CHA_VSYNC_PULSE_WIDTH_HIGH_REG	0x31
43 #define  CHA_VSYNC_POLARITY			BIT(7)
44 #define SN_CHA_HORIZONTAL_BACK_PORCH_REG	0x34
45 #define SN_CHA_VERTICAL_BACK_PORCH_REG		0x36
46 #define SN_CHA_HORIZONTAL_FRONT_PORCH_REG	0x38
47 #define SN_CHA_VERTICAL_FRONT_PORCH_REG		0x3A
48 #define SN_ENH_FRAME_REG			0x5A
49 #define  VSTREAM_ENABLE				BIT(3)
50 #define SN_DATA_FORMAT_REG			0x5B
51 #define SN_HPD_DISABLE_REG			0x5C
52 #define  HPD_DISABLE				BIT(0)
53 #define SN_AUX_WDATA_REG(x)			(0x64 + (x))
54 #define SN_AUX_ADDR_19_16_REG			0x74
55 #define SN_AUX_ADDR_15_8_REG			0x75
56 #define SN_AUX_ADDR_7_0_REG			0x76
57 #define SN_AUX_LENGTH_REG			0x77
58 #define SN_AUX_CMD_REG				0x78
59 #define  AUX_CMD_SEND				BIT(0)
60 #define  AUX_CMD_REQ(x)				((x) << 4)
61 #define SN_AUX_RDATA_REG(x)			(0x79 + (x))
62 #define SN_SSC_CONFIG_REG			0x93
63 #define  DP_NUM_LANES_MASK			GENMASK(5, 4)
64 #define  DP_NUM_LANES(x)			((x) << 4)
65 #define SN_DATARATE_CONFIG_REG			0x94
66 #define  DP_DATARATE_MASK			GENMASK(7, 5)
67 #define  DP_DATARATE(x)				((x) << 5)
68 #define SN_ML_TX_MODE_REG			0x96
69 #define  ML_TX_MAIN_LINK_OFF			0
70 #define  ML_TX_NORMAL_MODE			BIT(0)
71 #define SN_AUX_CMD_STATUS_REG			0xF4
72 #define  AUX_IRQ_STATUS_AUX_RPLY_TOUT		BIT(3)
73 #define  AUX_IRQ_STATUS_AUX_SHORT		BIT(5)
74 #define  AUX_IRQ_STATUS_NAT_I2C_FAIL		BIT(6)
75 
76 #define MIN_DSI_CLK_FREQ_MHZ	40
77 
78 /* fudge factor required to account for 8b/10b encoding */
79 #define DP_CLK_FUDGE_NUM	10
80 #define DP_CLK_FUDGE_DEN	8
81 
82 /* Matches DP_AUX_MAX_PAYLOAD_BYTES (for now) */
83 #define SN_AUX_MAX_PAYLOAD_BYTES	16
84 
85 #define SN_REGULATOR_SUPPLY_NUM		4
86 
87 struct ti_sn_bridge {
88 	struct device			*dev;
89 	struct regmap			*regmap;
90 	struct drm_dp_aux		aux;
91 	struct drm_bridge		bridge;
92 	struct drm_connector		connector;
93 	struct device_node		*host_node;
94 	struct mipi_dsi_device		*dsi;
95 	struct clk			*refclk;
96 	struct drm_panel		*panel;
97 	struct gpio_desc		*enable_gpio;
98 	struct regulator_bulk_data	supplies[SN_REGULATOR_SUPPLY_NUM];
99 };
100 
101 static const struct regmap_range ti_sn_bridge_volatile_ranges[] = {
102 	{ .range_min = 0, .range_max = 0xFF },
103 };
104 
105 static const struct regmap_access_table ti_sn_bridge_volatile_table = {
106 	.yes_ranges = ti_sn_bridge_volatile_ranges,
107 	.n_yes_ranges = ARRAY_SIZE(ti_sn_bridge_volatile_ranges),
108 };
109 
110 static const struct regmap_config ti_sn_bridge_regmap_config = {
111 	.reg_bits = 8,
112 	.val_bits = 8,
113 	.volatile_table = &ti_sn_bridge_volatile_table,
114 	.cache_type = REGCACHE_NONE,
115 };
116 
117 static void ti_sn_bridge_write_u16(struct ti_sn_bridge *pdata,
118 				   unsigned int reg, u16 val)
119 {
120 	regmap_write(pdata->regmap, reg, val & 0xFF);
121 	regmap_write(pdata->regmap, reg + 1, val >> 8);
122 }
123 
124 static int __maybe_unused ti_sn_bridge_resume(struct device *dev)
125 {
126 	struct ti_sn_bridge *pdata = dev_get_drvdata(dev);
127 	int ret;
128 
129 	ret = regulator_bulk_enable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies);
130 	if (ret) {
131 		DRM_ERROR("failed to enable supplies %d\n", ret);
132 		return ret;
133 	}
134 
135 	gpiod_set_value(pdata->enable_gpio, 1);
136 
137 	return ret;
138 }
139 
140 static int __maybe_unused ti_sn_bridge_suspend(struct device *dev)
141 {
142 	struct ti_sn_bridge *pdata = dev_get_drvdata(dev);
143 	int ret;
144 
145 	gpiod_set_value(pdata->enable_gpio, 0);
146 
147 	ret = regulator_bulk_disable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies);
148 	if (ret)
149 		DRM_ERROR("failed to disable supplies %d\n", ret);
150 
151 	return ret;
152 }
153 
154 static const struct dev_pm_ops ti_sn_bridge_pm_ops = {
155 	SET_RUNTIME_PM_OPS(ti_sn_bridge_suspend, ti_sn_bridge_resume, NULL)
156 };
157 
158 /* Connector funcs */
159 static struct ti_sn_bridge *
160 connector_to_ti_sn_bridge(struct drm_connector *connector)
161 {
162 	return container_of(connector, struct ti_sn_bridge, connector);
163 }
164 
165 static int ti_sn_bridge_connector_get_modes(struct drm_connector *connector)
166 {
167 	struct ti_sn_bridge *pdata = connector_to_ti_sn_bridge(connector);
168 
169 	return drm_panel_get_modes(pdata->panel);
170 }
171 
172 static enum drm_mode_status
173 ti_sn_bridge_connector_mode_valid(struct drm_connector *connector,
174 				  struct drm_display_mode *mode)
175 {
176 	/* maximum supported resolution is 4K at 60 fps */
177 	if (mode->clock > 594000)
178 		return MODE_CLOCK_HIGH;
179 
180 	return MODE_OK;
181 }
182 
183 static struct drm_connector_helper_funcs ti_sn_bridge_connector_helper_funcs = {
184 	.get_modes = ti_sn_bridge_connector_get_modes,
185 	.mode_valid = ti_sn_bridge_connector_mode_valid,
186 };
187 
188 static enum drm_connector_status
189 ti_sn_bridge_connector_detect(struct drm_connector *connector, bool force)
190 {
191 	/**
192 	 * TODO: Currently if drm_panel is present, then always
193 	 * return the status as connected. Need to add support to detect
194 	 * device state for hot pluggable scenarios.
195 	 */
196 	return connector_status_connected;
197 }
198 
199 static const struct drm_connector_funcs ti_sn_bridge_connector_funcs = {
200 	.fill_modes = drm_helper_probe_single_connector_modes,
201 	.detect = ti_sn_bridge_connector_detect,
202 	.destroy = drm_connector_cleanup,
203 	.reset = drm_atomic_helper_connector_reset,
204 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
205 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
206 };
207 
208 static struct ti_sn_bridge *bridge_to_ti_sn_bridge(struct drm_bridge *bridge)
209 {
210 	return container_of(bridge, struct ti_sn_bridge, bridge);
211 }
212 
213 static int ti_sn_bridge_parse_regulators(struct ti_sn_bridge *pdata)
214 {
215 	unsigned int i;
216 	const char * const ti_sn_bridge_supply_names[] = {
217 		"vcca", "vcc", "vccio", "vpll",
218 	};
219 
220 	for (i = 0; i < SN_REGULATOR_SUPPLY_NUM; i++)
221 		pdata->supplies[i].supply = ti_sn_bridge_supply_names[i];
222 
223 	return devm_regulator_bulk_get(pdata->dev, SN_REGULATOR_SUPPLY_NUM,
224 				       pdata->supplies);
225 }
226 
227 static int ti_sn_bridge_attach(struct drm_bridge *bridge)
228 {
229 	int ret, val;
230 	struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
231 	struct mipi_dsi_host *host;
232 	struct mipi_dsi_device *dsi;
233 	const struct mipi_dsi_device_info info = { .type = "ti_sn_bridge",
234 						   .channel = 0,
235 						   .node = NULL,
236 						 };
237 
238 	ret = drm_connector_init(bridge->dev, &pdata->connector,
239 				 &ti_sn_bridge_connector_funcs,
240 				 DRM_MODE_CONNECTOR_eDP);
241 	if (ret) {
242 		DRM_ERROR("Failed to initialize connector with drm\n");
243 		return ret;
244 	}
245 
246 	drm_connector_helper_add(&pdata->connector,
247 				 &ti_sn_bridge_connector_helper_funcs);
248 	drm_connector_attach_encoder(&pdata->connector, bridge->encoder);
249 
250 	/*
251 	 * TODO: ideally finding host resource and dsi dev registration needs
252 	 * to be done in bridge probe. But some existing DSI host drivers will
253 	 * wait for any of the drm_bridge/drm_panel to get added to the global
254 	 * bridge/panel list, before completing their probe. So if we do the
255 	 * dsi dev registration part in bridge probe, before populating in
256 	 * the global bridge list, then it will cause deadlock as dsi host probe
257 	 * will never complete, neither our bridge probe. So keeping it here
258 	 * will satisfy most of the existing host drivers. Once the host driver
259 	 * is fixed we can move the below code to bridge probe safely.
260 	 */
261 	host = of_find_mipi_dsi_host_by_node(pdata->host_node);
262 	if (!host) {
263 		DRM_ERROR("failed to find dsi host\n");
264 		ret = -ENODEV;
265 		goto err_dsi_host;
266 	}
267 
268 	dsi = mipi_dsi_device_register_full(host, &info);
269 	if (IS_ERR(dsi)) {
270 		DRM_ERROR("failed to create dsi device\n");
271 		ret = PTR_ERR(dsi);
272 		goto err_dsi_host;
273 	}
274 
275 	/* TODO: setting to 4 lanes always for now */
276 	dsi->lanes = 4;
277 	dsi->format = MIPI_DSI_FMT_RGB888;
278 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
279 			  MIPI_DSI_MODE_EOT_PACKET | MIPI_DSI_MODE_VIDEO_HSE;
280 
281 	/* check if continuous dsi clock is required or not */
282 	pm_runtime_get_sync(pdata->dev);
283 	regmap_read(pdata->regmap, SN_DPPLL_SRC_REG, &val);
284 	pm_runtime_put(pdata->dev);
285 	if (!(val & DPPLL_CLK_SRC_DSICLK))
286 		dsi->mode_flags |= MIPI_DSI_CLOCK_NON_CONTINUOUS;
287 
288 	ret = mipi_dsi_attach(dsi);
289 	if (ret < 0) {
290 		DRM_ERROR("failed to attach dsi to host\n");
291 		goto err_dsi_attach;
292 	}
293 	pdata->dsi = dsi;
294 
295 	/* attach panel to bridge */
296 	drm_panel_attach(pdata->panel, &pdata->connector);
297 
298 	return 0;
299 
300 err_dsi_attach:
301 	mipi_dsi_device_unregister(dsi);
302 err_dsi_host:
303 	drm_connector_cleanup(&pdata->connector);
304 	return ret;
305 }
306 
307 static void ti_sn_bridge_disable(struct drm_bridge *bridge)
308 {
309 	struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
310 
311 	drm_panel_disable(pdata->panel);
312 
313 	/* disable video stream */
314 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE, 0);
315 	/* semi auto link training mode OFF */
316 	regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0);
317 	/* disable DP PLL */
318 	regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
319 
320 	drm_panel_unprepare(pdata->panel);
321 }
322 
323 static u32 ti_sn_bridge_get_dsi_freq(struct ti_sn_bridge *pdata)
324 {
325 	u32 bit_rate_khz, clk_freq_khz;
326 	struct drm_display_mode *mode =
327 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
328 
329 	bit_rate_khz = mode->clock *
330 			mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
331 	clk_freq_khz = bit_rate_khz / (pdata->dsi->lanes * 2);
332 
333 	return clk_freq_khz;
334 }
335 
336 /* clk frequencies supported by bridge in Hz in case derived from REFCLK pin */
337 static const u32 ti_sn_bridge_refclk_lut[] = {
338 	12000000,
339 	19200000,
340 	26000000,
341 	27000000,
342 	38400000,
343 };
344 
345 /* clk frequencies supported by bridge in Hz in case derived from DACP/N pin */
346 static const u32 ti_sn_bridge_dsiclk_lut[] = {
347 	468000000,
348 	384000000,
349 	416000000,
350 	486000000,
351 	460800000,
352 };
353 
354 static void ti_sn_bridge_set_refclk_freq(struct ti_sn_bridge *pdata)
355 {
356 	int i;
357 	u32 refclk_rate;
358 	const u32 *refclk_lut;
359 	size_t refclk_lut_size;
360 
361 	if (pdata->refclk) {
362 		refclk_rate = clk_get_rate(pdata->refclk);
363 		refclk_lut = ti_sn_bridge_refclk_lut;
364 		refclk_lut_size = ARRAY_SIZE(ti_sn_bridge_refclk_lut);
365 		clk_prepare_enable(pdata->refclk);
366 	} else {
367 		refclk_rate = ti_sn_bridge_get_dsi_freq(pdata) * 1000;
368 		refclk_lut = ti_sn_bridge_dsiclk_lut;
369 		refclk_lut_size = ARRAY_SIZE(ti_sn_bridge_dsiclk_lut);
370 	}
371 
372 	/* for i equals to refclk_lut_size means default frequency */
373 	for (i = 0; i < refclk_lut_size; i++)
374 		if (refclk_lut[i] == refclk_rate)
375 			break;
376 
377 	regmap_update_bits(pdata->regmap, SN_DPPLL_SRC_REG, REFCLK_FREQ_MASK,
378 			   REFCLK_FREQ(i));
379 }
380 
381 /**
382  * LUT index corresponds to register value and
383  * LUT values corresponds to dp data rate supported
384  * by the bridge in Mbps unit.
385  */
386 static const unsigned int ti_sn_bridge_dp_rate_lut[] = {
387 	0, 1620, 2160, 2430, 2700, 3240, 4320, 5400
388 };
389 
390 static void ti_sn_bridge_set_dsi_dp_rate(struct ti_sn_bridge *pdata)
391 {
392 	unsigned int bit_rate_mhz, clk_freq_mhz, dp_rate_mhz;
393 	unsigned int val, i;
394 	struct drm_display_mode *mode =
395 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
396 
397 	/* set DSIA clk frequency */
398 	bit_rate_mhz = (mode->clock / 1000) *
399 			mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
400 	clk_freq_mhz = bit_rate_mhz / (pdata->dsi->lanes * 2);
401 
402 	/* for each increment in val, frequency increases by 5MHz */
403 	val = (MIN_DSI_CLK_FREQ_MHZ / 5) +
404 		(((clk_freq_mhz - MIN_DSI_CLK_FREQ_MHZ) / 5) & 0xFF);
405 	regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val);
406 
407 	/* set DP data rate */
408 	dp_rate_mhz = ((bit_rate_mhz / pdata->dsi->lanes) * DP_CLK_FUDGE_NUM) /
409 							DP_CLK_FUDGE_DEN;
410 	for (i = 0; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++)
411 		if (ti_sn_bridge_dp_rate_lut[i] > dp_rate_mhz)
412 			break;
413 
414 	regmap_update_bits(pdata->regmap, SN_DATARATE_CONFIG_REG,
415 			   DP_DATARATE_MASK, DP_DATARATE(i));
416 }
417 
418 static void ti_sn_bridge_set_video_timings(struct ti_sn_bridge *pdata)
419 {
420 	struct drm_display_mode *mode =
421 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
422 	u8 hsync_polarity = 0, vsync_polarity = 0;
423 
424 	if (mode->flags & DRM_MODE_FLAG_PHSYNC)
425 		hsync_polarity = CHA_HSYNC_POLARITY;
426 	if (mode->flags & DRM_MODE_FLAG_PVSYNC)
427 		vsync_polarity = CHA_VSYNC_POLARITY;
428 
429 	ti_sn_bridge_write_u16(pdata, SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG,
430 			       mode->hdisplay);
431 	ti_sn_bridge_write_u16(pdata, SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG,
432 			       mode->vdisplay);
433 	regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG,
434 		     (mode->hsync_end - mode->hsync_start) & 0xFF);
435 	regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_HIGH_REG,
436 		     (((mode->hsync_end - mode->hsync_start) >> 8) & 0x7F) |
437 		     hsync_polarity);
438 	regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG,
439 		     (mode->vsync_end - mode->vsync_start) & 0xFF);
440 	regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_HIGH_REG,
441 		     (((mode->vsync_end - mode->vsync_start) >> 8) & 0x7F) |
442 		     vsync_polarity);
443 
444 	regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_BACK_PORCH_REG,
445 		     (mode->htotal - mode->hsync_end) & 0xFF);
446 	regmap_write(pdata->regmap, SN_CHA_VERTICAL_BACK_PORCH_REG,
447 		     (mode->vtotal - mode->vsync_end) & 0xFF);
448 
449 	regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_FRONT_PORCH_REG,
450 		     (mode->hsync_start - mode->hdisplay) & 0xFF);
451 	regmap_write(pdata->regmap, SN_CHA_VERTICAL_FRONT_PORCH_REG,
452 		     (mode->vsync_start - mode->vdisplay) & 0xFF);
453 
454 	usleep_range(10000, 10500); /* 10ms delay recommended by spec */
455 }
456 
457 static void ti_sn_bridge_enable(struct drm_bridge *bridge)
458 {
459 	struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
460 	unsigned int val;
461 	int ret;
462 
463 	/* DSI_A lane config */
464 	val = CHA_DSI_LANES(4 - pdata->dsi->lanes);
465 	regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG,
466 			   CHA_DSI_LANES_MASK, val);
467 
468 	/* DP lane config */
469 	val = DP_NUM_LANES(pdata->dsi->lanes - 1);
470 	regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK,
471 			   val);
472 
473 	/* set dsi/dp clk frequency value */
474 	ti_sn_bridge_set_dsi_dp_rate(pdata);
475 
476 	/* enable DP PLL */
477 	regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
478 
479 	ret = regmap_read_poll_timeout(pdata->regmap, SN_DPPLL_SRC_REG, val,
480 				       val & DPPLL_SRC_DP_PLL_LOCK, 1000,
481 				       50 * 1000);
482 	if (ret) {
483 		DRM_ERROR("DP_PLL_LOCK polling failed (%d)\n", ret);
484 		return;
485 	}
486 
487 	/**
488 	 * The SN65DSI86 only supports ASSR Display Authentication method and
489 	 * this method is enabled by default. An eDP panel must support this
490 	 * authentication method. We need to enable this method in the eDP panel
491 	 * at DisplayPort address 0x0010A prior to link training.
492 	 */
493 	drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET,
494 			   DP_ALTERNATE_SCRAMBLER_RESET_ENABLE);
495 
496 	/* Semi auto link training mode */
497 	regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A);
498 	ret = regmap_read_poll_timeout(pdata->regmap, SN_ML_TX_MODE_REG, val,
499 				       val == ML_TX_MAIN_LINK_OFF ||
500 				       val == ML_TX_NORMAL_MODE, 1000,
501 				       500 * 1000);
502 	if (ret) {
503 		DRM_ERROR("Training complete polling failed (%d)\n", ret);
504 		return;
505 	} else if (val == ML_TX_MAIN_LINK_OFF) {
506 		DRM_ERROR("Link training failed, link is off\n");
507 		return;
508 	}
509 
510 	/* config video parameters */
511 	ti_sn_bridge_set_video_timings(pdata);
512 
513 	/* enable video stream */
514 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE,
515 			   VSTREAM_ENABLE);
516 
517 	drm_panel_enable(pdata->panel);
518 }
519 
520 static void ti_sn_bridge_pre_enable(struct drm_bridge *bridge)
521 {
522 	struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
523 
524 	pm_runtime_get_sync(pdata->dev);
525 
526 	/* configure bridge ref_clk */
527 	ti_sn_bridge_set_refclk_freq(pdata);
528 
529 	/*
530 	 * HPD on this bridge chip is a bit useless.  This is an eDP bridge
531 	 * so the HPD is an internal signal that's only there to signal that
532 	 * the panel is done powering up.  ...but the bridge chip debounces
533 	 * this signal by between 100 ms and 400 ms (depending on process,
534 	 * voltage, and temperate--I measured it at about 200 ms).  One
535 	 * particular panel asserted HPD 84 ms after it was powered on meaning
536 	 * that we saw HPD 284 ms after power on.  ...but the same panel said
537 	 * that instead of looking at HPD you could just hardcode a delay of
538 	 * 200 ms.  We'll assume that the panel driver will have the hardcoded
539 	 * delay in its prepare and always disable HPD.
540 	 *
541 	 * If HPD somehow makes sense on some future panel we'll have to
542 	 * change this to be conditional on someone specifying that HPD should
543 	 * be used.
544 	 */
545 	regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE,
546 			   HPD_DISABLE);
547 
548 	drm_panel_prepare(pdata->panel);
549 }
550 
551 static void ti_sn_bridge_post_disable(struct drm_bridge *bridge)
552 {
553 	struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
554 
555 	if (pdata->refclk)
556 		clk_disable_unprepare(pdata->refclk);
557 
558 	pm_runtime_put_sync(pdata->dev);
559 }
560 
561 static const struct drm_bridge_funcs ti_sn_bridge_funcs = {
562 	.attach = ti_sn_bridge_attach,
563 	.pre_enable = ti_sn_bridge_pre_enable,
564 	.enable = ti_sn_bridge_enable,
565 	.disable = ti_sn_bridge_disable,
566 	.post_disable = ti_sn_bridge_post_disable,
567 };
568 
569 static struct ti_sn_bridge *aux_to_ti_sn_bridge(struct drm_dp_aux *aux)
570 {
571 	return container_of(aux, struct ti_sn_bridge, aux);
572 }
573 
574 static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux,
575 				  struct drm_dp_aux_msg *msg)
576 {
577 	struct ti_sn_bridge *pdata = aux_to_ti_sn_bridge(aux);
578 	u32 request = msg->request & ~DP_AUX_I2C_MOT;
579 	u32 request_val = AUX_CMD_REQ(msg->request);
580 	u8 *buf = (u8 *)msg->buffer;
581 	unsigned int val;
582 	int ret, i;
583 
584 	if (msg->size > SN_AUX_MAX_PAYLOAD_BYTES)
585 		return -EINVAL;
586 
587 	switch (request) {
588 	case DP_AUX_NATIVE_WRITE:
589 	case DP_AUX_I2C_WRITE:
590 	case DP_AUX_NATIVE_READ:
591 	case DP_AUX_I2C_READ:
592 		regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val);
593 		break;
594 	default:
595 		return -EINVAL;
596 	}
597 
598 	regmap_write(pdata->regmap, SN_AUX_ADDR_19_16_REG,
599 		     (msg->address >> 16) & 0xF);
600 	regmap_write(pdata->regmap, SN_AUX_ADDR_15_8_REG,
601 		     (msg->address >> 8) & 0xFF);
602 	regmap_write(pdata->regmap, SN_AUX_ADDR_7_0_REG, msg->address & 0xFF);
603 
604 	regmap_write(pdata->regmap, SN_AUX_LENGTH_REG, msg->size);
605 
606 	if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE) {
607 		for (i = 0; i < msg->size; i++)
608 			regmap_write(pdata->regmap, SN_AUX_WDATA_REG(i),
609 				     buf[i]);
610 	}
611 
612 	regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val | AUX_CMD_SEND);
613 
614 	ret = regmap_read_poll_timeout(pdata->regmap, SN_AUX_CMD_REG, val,
615 				       !(val & AUX_CMD_SEND), 200,
616 				       50 * 1000);
617 	if (ret)
618 		return ret;
619 
620 	ret = regmap_read(pdata->regmap, SN_AUX_CMD_STATUS_REG, &val);
621 	if (ret)
622 		return ret;
623 	else if ((val & AUX_IRQ_STATUS_NAT_I2C_FAIL)
624 		 || (val & AUX_IRQ_STATUS_AUX_RPLY_TOUT)
625 		 || (val & AUX_IRQ_STATUS_AUX_SHORT))
626 		return -ENXIO;
627 
628 	if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE)
629 		return msg->size;
630 
631 	for (i = 0; i < msg->size; i++) {
632 		unsigned int val;
633 		ret = regmap_read(pdata->regmap, SN_AUX_RDATA_REG(i),
634 				  &val);
635 		if (ret)
636 			return ret;
637 
638 		WARN_ON(val & ~0xFF);
639 		buf[i] = (u8)(val & 0xFF);
640 	}
641 
642 	return msg->size;
643 }
644 
645 static int ti_sn_bridge_parse_dsi_host(struct ti_sn_bridge *pdata)
646 {
647 	struct device_node *np = pdata->dev->of_node;
648 
649 	pdata->host_node = of_graph_get_remote_node(np, 0, 0);
650 
651 	if (!pdata->host_node) {
652 		DRM_ERROR("remote dsi host node not found\n");
653 		return -ENODEV;
654 	}
655 
656 	return 0;
657 }
658 
659 static int ti_sn_bridge_probe(struct i2c_client *client,
660 			      const struct i2c_device_id *id)
661 {
662 	struct ti_sn_bridge *pdata;
663 	int ret;
664 
665 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
666 		DRM_ERROR("device doesn't support I2C\n");
667 		return -ENODEV;
668 	}
669 
670 	pdata = devm_kzalloc(&client->dev, sizeof(struct ti_sn_bridge),
671 			     GFP_KERNEL);
672 	if (!pdata)
673 		return -ENOMEM;
674 
675 	pdata->regmap = devm_regmap_init_i2c(client,
676 					     &ti_sn_bridge_regmap_config);
677 	if (IS_ERR(pdata->regmap)) {
678 		DRM_ERROR("regmap i2c init failed\n");
679 		return PTR_ERR(pdata->regmap);
680 	}
681 
682 	pdata->dev = &client->dev;
683 
684 	ret = drm_of_find_panel_or_bridge(pdata->dev->of_node, 1, 0,
685 					  &pdata->panel, NULL);
686 	if (ret) {
687 		DRM_ERROR("could not find any panel node\n");
688 		return ret;
689 	}
690 
691 	dev_set_drvdata(&client->dev, pdata);
692 
693 	pdata->enable_gpio = devm_gpiod_get(pdata->dev, "enable",
694 					    GPIOD_OUT_LOW);
695 	if (IS_ERR(pdata->enable_gpio)) {
696 		DRM_ERROR("failed to get enable gpio from DT\n");
697 		ret = PTR_ERR(pdata->enable_gpio);
698 		return ret;
699 	}
700 
701 	ret = ti_sn_bridge_parse_regulators(pdata);
702 	if (ret) {
703 		DRM_ERROR("failed to parse regulators\n");
704 		return ret;
705 	}
706 
707 	pdata->refclk = devm_clk_get(pdata->dev, "refclk");
708 	if (IS_ERR(pdata->refclk)) {
709 		ret = PTR_ERR(pdata->refclk);
710 		if (ret == -EPROBE_DEFER)
711 			return ret;
712 		DRM_DEBUG_KMS("refclk not found\n");
713 		pdata->refclk = NULL;
714 	}
715 
716 	ret = ti_sn_bridge_parse_dsi_host(pdata);
717 	if (ret)
718 		return ret;
719 
720 	pm_runtime_enable(pdata->dev);
721 
722 	i2c_set_clientdata(client, pdata);
723 
724 	pdata->aux.name = "ti-sn65dsi86-aux";
725 	pdata->aux.dev = pdata->dev;
726 	pdata->aux.transfer = ti_sn_aux_transfer;
727 	drm_dp_aux_register(&pdata->aux);
728 
729 	pdata->bridge.funcs = &ti_sn_bridge_funcs;
730 	pdata->bridge.of_node = client->dev.of_node;
731 
732 	drm_bridge_add(&pdata->bridge);
733 
734 	return 0;
735 }
736 
737 static int ti_sn_bridge_remove(struct i2c_client *client)
738 {
739 	struct ti_sn_bridge *pdata = i2c_get_clientdata(client);
740 
741 	if (!pdata)
742 		return -EINVAL;
743 
744 	of_node_put(pdata->host_node);
745 
746 	pm_runtime_disable(pdata->dev);
747 
748 	if (pdata->dsi) {
749 		mipi_dsi_detach(pdata->dsi);
750 		mipi_dsi_device_unregister(pdata->dsi);
751 	}
752 
753 	drm_bridge_remove(&pdata->bridge);
754 
755 	return 0;
756 }
757 
758 static struct i2c_device_id ti_sn_bridge_id[] = {
759 	{ "ti,sn65dsi86", 0},
760 	{},
761 };
762 MODULE_DEVICE_TABLE(i2c, ti_sn_bridge_id);
763 
764 static const struct of_device_id ti_sn_bridge_match_table[] = {
765 	{.compatible = "ti,sn65dsi86"},
766 	{},
767 };
768 MODULE_DEVICE_TABLE(of, ti_sn_bridge_match_table);
769 
770 static struct i2c_driver ti_sn_bridge_driver = {
771 	.driver = {
772 		.name = "ti_sn65dsi86",
773 		.of_match_table = ti_sn_bridge_match_table,
774 		.pm = &ti_sn_bridge_pm_ops,
775 	},
776 	.probe = ti_sn_bridge_probe,
777 	.remove = ti_sn_bridge_remove,
778 	.id_table = ti_sn_bridge_id,
779 };
780 module_i2c_driver(ti_sn_bridge_driver);
781 
782 MODULE_AUTHOR("Sandeep Panda <spanda@codeaurora.org>");
783 MODULE_DESCRIPTION("sn65dsi86 DSI to eDP bridge driver");
784 MODULE_LICENSE("GPL v2");
785