1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2018, The Linux Foundation. All rights reserved.
4  * datasheet: https://www.ti.com/lit/ds/symlink/sn65dsi86.pdf
5  */
6 
7 #include <linux/bits.h>
8 #include <linux/clk.h>
9 #include <linux/debugfs.h>
10 #include <linux/gpio/consumer.h>
11 #include <linux/gpio/driver.h>
12 #include <linux/i2c.h>
13 #include <linux/iopoll.h>
14 #include <linux/module.h>
15 #include <linux/of_graph.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/regmap.h>
18 #include <linux/regulator/consumer.h>
19 
20 #include <drm/drm_atomic.h>
21 #include <drm/drm_atomic_helper.h>
22 #include <drm/drm_bridge.h>
23 #include <drm/drm_dp_helper.h>
24 #include <drm/drm_mipi_dsi.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 
30 #define SN_DEVICE_REV_REG			0x08
31 #define SN_DPPLL_SRC_REG			0x0A
32 #define  DPPLL_CLK_SRC_DSICLK			BIT(0)
33 #define  REFCLK_FREQ_MASK			GENMASK(3, 1)
34 #define  REFCLK_FREQ(x)				((x) << 1)
35 #define  DPPLL_SRC_DP_PLL_LOCK			BIT(7)
36 #define SN_PLL_ENABLE_REG			0x0D
37 #define SN_DSI_LANES_REG			0x10
38 #define  CHA_DSI_LANES_MASK			GENMASK(4, 3)
39 #define  CHA_DSI_LANES(x)			((x) << 3)
40 #define SN_DSIA_CLK_FREQ_REG			0x12
41 #define SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG	0x20
42 #define SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG	0x24
43 #define SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG	0x2C
44 #define SN_CHA_HSYNC_PULSE_WIDTH_HIGH_REG	0x2D
45 #define  CHA_HSYNC_POLARITY			BIT(7)
46 #define SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG	0x30
47 #define SN_CHA_VSYNC_PULSE_WIDTH_HIGH_REG	0x31
48 #define  CHA_VSYNC_POLARITY			BIT(7)
49 #define SN_CHA_HORIZONTAL_BACK_PORCH_REG	0x34
50 #define SN_CHA_VERTICAL_BACK_PORCH_REG		0x36
51 #define SN_CHA_HORIZONTAL_FRONT_PORCH_REG	0x38
52 #define SN_CHA_VERTICAL_FRONT_PORCH_REG		0x3A
53 #define SN_LN_ASSIGN_REG			0x59
54 #define  LN_ASSIGN_WIDTH			2
55 #define SN_ENH_FRAME_REG			0x5A
56 #define  VSTREAM_ENABLE				BIT(3)
57 #define  LN_POLRS_OFFSET			4
58 #define  LN_POLRS_MASK				0xf0
59 #define SN_DATA_FORMAT_REG			0x5B
60 #define  BPP_18_RGB				BIT(0)
61 #define SN_HPD_DISABLE_REG			0x5C
62 #define  HPD_DISABLE				BIT(0)
63 #define SN_GPIO_IO_REG				0x5E
64 #define  SN_GPIO_INPUT_SHIFT			4
65 #define  SN_GPIO_OUTPUT_SHIFT			0
66 #define SN_GPIO_CTRL_REG			0x5F
67 #define  SN_GPIO_MUX_INPUT			0
68 #define  SN_GPIO_MUX_OUTPUT			1
69 #define  SN_GPIO_MUX_SPECIAL			2
70 #define  SN_GPIO_MUX_MASK			0x3
71 #define SN_AUX_WDATA_REG(x)			(0x64 + (x))
72 #define SN_AUX_ADDR_19_16_REG			0x74
73 #define SN_AUX_ADDR_15_8_REG			0x75
74 #define SN_AUX_ADDR_7_0_REG			0x76
75 #define SN_AUX_LENGTH_REG			0x77
76 #define SN_AUX_CMD_REG				0x78
77 #define  AUX_CMD_SEND				BIT(0)
78 #define  AUX_CMD_REQ(x)				((x) << 4)
79 #define SN_AUX_RDATA_REG(x)			(0x79 + (x))
80 #define SN_SSC_CONFIG_REG			0x93
81 #define  DP_NUM_LANES_MASK			GENMASK(5, 4)
82 #define  DP_NUM_LANES(x)			((x) << 4)
83 #define SN_DATARATE_CONFIG_REG			0x94
84 #define  DP_DATARATE_MASK			GENMASK(7, 5)
85 #define  DP_DATARATE(x)				((x) << 5)
86 #define SN_ML_TX_MODE_REG			0x96
87 #define  ML_TX_MAIN_LINK_OFF			0
88 #define  ML_TX_NORMAL_MODE			BIT(0)
89 #define SN_AUX_CMD_STATUS_REG			0xF4
90 #define  AUX_IRQ_STATUS_AUX_RPLY_TOUT		BIT(3)
91 #define  AUX_IRQ_STATUS_AUX_SHORT		BIT(5)
92 #define  AUX_IRQ_STATUS_NAT_I2C_FAIL		BIT(6)
93 
94 #define MIN_DSI_CLK_FREQ_MHZ	40
95 
96 /* fudge factor required to account for 8b/10b encoding */
97 #define DP_CLK_FUDGE_NUM	10
98 #define DP_CLK_FUDGE_DEN	8
99 
100 /* Matches DP_AUX_MAX_PAYLOAD_BYTES (for now) */
101 #define SN_AUX_MAX_PAYLOAD_BYTES	16
102 
103 #define SN_REGULATOR_SUPPLY_NUM		4
104 
105 #define SN_MAX_DP_LANES			4
106 #define SN_NUM_GPIOS			4
107 #define SN_GPIO_PHYSICAL_OFFSET		1
108 
109 /**
110  * struct ti_sn_bridge - Platform data for ti-sn65dsi86 driver.
111  * @dev:          Pointer to our device.
112  * @regmap:       Regmap for accessing i2c.
113  * @aux:          Our aux channel.
114  * @bridge:       Our bridge.
115  * @connector:    Our connector.
116  * @debugfs:      Used for managing our debugfs.
117  * @host_node:    Remote DSI node.
118  * @dsi:          Our MIPI DSI source.
119  * @refclk:       Our reference clock.
120  * @panel:        Our panel.
121  * @enable_gpio:  The GPIO we toggle to enable the bridge.
122  * @supplies:     Data for bulk enabling/disabling our regulators.
123  * @dp_lanes:     Count of dp_lanes we're using.
124  * @ln_assign:    Value to program to the LN_ASSIGN register.
125  * @ln_polrs:     Value for the 4-bit LN_POLRS field of SN_ENH_FRAME_REG.
126  *
127  * @gchip:        If we expose our GPIOs, this is used.
128  * @gchip_output: A cache of whether we've set GPIOs to output.  This
129  *                serves double-duty of keeping track of the direction and
130  *                also keeping track of whether we've incremented the
131  *                pm_runtime reference count for this pin, which we do
132  *                whenever a pin is configured as an output.  This is a
133  *                bitmap so we can do atomic ops on it without an extra
134  *                lock so concurrent users of our 4 GPIOs don't stomp on
135  *                each other's read-modify-write.
136  */
137 struct ti_sn_bridge {
138 	struct device			*dev;
139 	struct regmap			*regmap;
140 	struct drm_dp_aux		aux;
141 	struct drm_bridge		bridge;
142 	struct drm_connector		connector;
143 	struct dentry			*debugfs;
144 	struct device_node		*host_node;
145 	struct mipi_dsi_device		*dsi;
146 	struct clk			*refclk;
147 	struct drm_panel		*panel;
148 	struct gpio_desc		*enable_gpio;
149 	struct regulator_bulk_data	supplies[SN_REGULATOR_SUPPLY_NUM];
150 	int				dp_lanes;
151 	u8				ln_assign;
152 	u8				ln_polrs;
153 
154 #if defined(CONFIG_OF_GPIO)
155 	struct gpio_chip		gchip;
156 	DECLARE_BITMAP(gchip_output, SN_NUM_GPIOS);
157 #endif
158 };
159 
160 static const struct regmap_range ti_sn_bridge_volatile_ranges[] = {
161 	{ .range_min = 0, .range_max = 0xFF },
162 };
163 
164 static const struct regmap_access_table ti_sn_bridge_volatile_table = {
165 	.yes_ranges = ti_sn_bridge_volatile_ranges,
166 	.n_yes_ranges = ARRAY_SIZE(ti_sn_bridge_volatile_ranges),
167 };
168 
169 static const struct regmap_config ti_sn_bridge_regmap_config = {
170 	.reg_bits = 8,
171 	.val_bits = 8,
172 	.volatile_table = &ti_sn_bridge_volatile_table,
173 	.cache_type = REGCACHE_NONE,
174 };
175 
176 static void ti_sn_bridge_write_u16(struct ti_sn_bridge *pdata,
177 				   unsigned int reg, u16 val)
178 {
179 	regmap_write(pdata->regmap, reg, val & 0xFF);
180 	regmap_write(pdata->regmap, reg + 1, val >> 8);
181 }
182 
183 static int __maybe_unused ti_sn_bridge_resume(struct device *dev)
184 {
185 	struct ti_sn_bridge *pdata = dev_get_drvdata(dev);
186 	int ret;
187 
188 	ret = regulator_bulk_enable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies);
189 	if (ret) {
190 		DRM_ERROR("failed to enable supplies %d\n", ret);
191 		return ret;
192 	}
193 
194 	gpiod_set_value(pdata->enable_gpio, 1);
195 
196 	return ret;
197 }
198 
199 static int __maybe_unused ti_sn_bridge_suspend(struct device *dev)
200 {
201 	struct ti_sn_bridge *pdata = dev_get_drvdata(dev);
202 	int ret;
203 
204 	gpiod_set_value(pdata->enable_gpio, 0);
205 
206 	ret = regulator_bulk_disable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies);
207 	if (ret)
208 		DRM_ERROR("failed to disable supplies %d\n", ret);
209 
210 	return ret;
211 }
212 
213 static const struct dev_pm_ops ti_sn_bridge_pm_ops = {
214 	SET_RUNTIME_PM_OPS(ti_sn_bridge_suspend, ti_sn_bridge_resume, NULL)
215 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
216 				pm_runtime_force_resume)
217 };
218 
219 static int status_show(struct seq_file *s, void *data)
220 {
221 	struct ti_sn_bridge *pdata = s->private;
222 	unsigned int reg, val;
223 
224 	seq_puts(s, "STATUS REGISTERS:\n");
225 
226 	pm_runtime_get_sync(pdata->dev);
227 
228 	/* IRQ Status Registers, see Table 31 in datasheet */
229 	for (reg = 0xf0; reg <= 0xf8; reg++) {
230 		regmap_read(pdata->regmap, reg, &val);
231 		seq_printf(s, "[0x%02x] = 0x%08x\n", reg, val);
232 	}
233 
234 	pm_runtime_put(pdata->dev);
235 
236 	return 0;
237 }
238 
239 DEFINE_SHOW_ATTRIBUTE(status);
240 
241 static void ti_sn_debugfs_init(struct ti_sn_bridge *pdata)
242 {
243 	pdata->debugfs = debugfs_create_dir(dev_name(pdata->dev), NULL);
244 
245 	debugfs_create_file("status", 0600, pdata->debugfs, pdata,
246 			&status_fops);
247 }
248 
249 static void ti_sn_debugfs_remove(struct ti_sn_bridge *pdata)
250 {
251 	debugfs_remove_recursive(pdata->debugfs);
252 	pdata->debugfs = NULL;
253 }
254 
255 /* Connector funcs */
256 static struct ti_sn_bridge *
257 connector_to_ti_sn_bridge(struct drm_connector *connector)
258 {
259 	return container_of(connector, struct ti_sn_bridge, connector);
260 }
261 
262 static int ti_sn_bridge_connector_get_modes(struct drm_connector *connector)
263 {
264 	struct ti_sn_bridge *pdata = connector_to_ti_sn_bridge(connector);
265 
266 	return drm_panel_get_modes(pdata->panel, connector);
267 }
268 
269 static enum drm_mode_status
270 ti_sn_bridge_connector_mode_valid(struct drm_connector *connector,
271 				  struct drm_display_mode *mode)
272 {
273 	/* maximum supported resolution is 4K at 60 fps */
274 	if (mode->clock > 594000)
275 		return MODE_CLOCK_HIGH;
276 
277 	return MODE_OK;
278 }
279 
280 static struct drm_connector_helper_funcs ti_sn_bridge_connector_helper_funcs = {
281 	.get_modes = ti_sn_bridge_connector_get_modes,
282 	.mode_valid = ti_sn_bridge_connector_mode_valid,
283 };
284 
285 static enum drm_connector_status
286 ti_sn_bridge_connector_detect(struct drm_connector *connector, bool force)
287 {
288 	/**
289 	 * TODO: Currently if drm_panel is present, then always
290 	 * return the status as connected. Need to add support to detect
291 	 * device state for hot pluggable scenarios.
292 	 */
293 	return connector_status_connected;
294 }
295 
296 static const struct drm_connector_funcs ti_sn_bridge_connector_funcs = {
297 	.fill_modes = drm_helper_probe_single_connector_modes,
298 	.detect = ti_sn_bridge_connector_detect,
299 	.destroy = drm_connector_cleanup,
300 	.reset = drm_atomic_helper_connector_reset,
301 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
302 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
303 };
304 
305 static struct ti_sn_bridge *bridge_to_ti_sn_bridge(struct drm_bridge *bridge)
306 {
307 	return container_of(bridge, struct ti_sn_bridge, bridge);
308 }
309 
310 static int ti_sn_bridge_parse_regulators(struct ti_sn_bridge *pdata)
311 {
312 	unsigned int i;
313 	const char * const ti_sn_bridge_supply_names[] = {
314 		"vcca", "vcc", "vccio", "vpll",
315 	};
316 
317 	for (i = 0; i < SN_REGULATOR_SUPPLY_NUM; i++)
318 		pdata->supplies[i].supply = ti_sn_bridge_supply_names[i];
319 
320 	return devm_regulator_bulk_get(pdata->dev, SN_REGULATOR_SUPPLY_NUM,
321 				       pdata->supplies);
322 }
323 
324 static int ti_sn_bridge_attach(struct drm_bridge *bridge,
325 			       enum drm_bridge_attach_flags flags)
326 {
327 	int ret, val;
328 	struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
329 	struct mipi_dsi_host *host;
330 	struct mipi_dsi_device *dsi;
331 	const struct mipi_dsi_device_info info = { .type = "ti_sn_bridge",
332 						   .channel = 0,
333 						   .node = NULL,
334 						 };
335 
336 	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
337 		DRM_ERROR("Fix bridge driver to make connector optional!");
338 		return -EINVAL;
339 	}
340 
341 	ret = drm_connector_init(bridge->dev, &pdata->connector,
342 				 &ti_sn_bridge_connector_funcs,
343 				 DRM_MODE_CONNECTOR_eDP);
344 	if (ret) {
345 		DRM_ERROR("Failed to initialize connector with drm\n");
346 		return ret;
347 	}
348 
349 	drm_connector_helper_add(&pdata->connector,
350 				 &ti_sn_bridge_connector_helper_funcs);
351 	drm_connector_attach_encoder(&pdata->connector, bridge->encoder);
352 
353 	/*
354 	 * TODO: ideally finding host resource and dsi dev registration needs
355 	 * to be done in bridge probe. But some existing DSI host drivers will
356 	 * wait for any of the drm_bridge/drm_panel to get added to the global
357 	 * bridge/panel list, before completing their probe. So if we do the
358 	 * dsi dev registration part in bridge probe, before populating in
359 	 * the global bridge list, then it will cause deadlock as dsi host probe
360 	 * will never complete, neither our bridge probe. So keeping it here
361 	 * will satisfy most of the existing host drivers. Once the host driver
362 	 * is fixed we can move the below code to bridge probe safely.
363 	 */
364 	host = of_find_mipi_dsi_host_by_node(pdata->host_node);
365 	if (!host) {
366 		DRM_ERROR("failed to find dsi host\n");
367 		ret = -ENODEV;
368 		goto err_dsi_host;
369 	}
370 
371 	dsi = mipi_dsi_device_register_full(host, &info);
372 	if (IS_ERR(dsi)) {
373 		DRM_ERROR("failed to create dsi device\n");
374 		ret = PTR_ERR(dsi);
375 		goto err_dsi_host;
376 	}
377 
378 	/* TODO: setting to 4 MIPI lanes always for now */
379 	dsi->lanes = 4;
380 	dsi->format = MIPI_DSI_FMT_RGB888;
381 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
382 
383 	/* check if continuous dsi clock is required or not */
384 	pm_runtime_get_sync(pdata->dev);
385 	regmap_read(pdata->regmap, SN_DPPLL_SRC_REG, &val);
386 	pm_runtime_put(pdata->dev);
387 	if (!(val & DPPLL_CLK_SRC_DSICLK))
388 		dsi->mode_flags |= MIPI_DSI_CLOCK_NON_CONTINUOUS;
389 
390 	ret = mipi_dsi_attach(dsi);
391 	if (ret < 0) {
392 		DRM_ERROR("failed to attach dsi to host\n");
393 		goto err_dsi_attach;
394 	}
395 	pdata->dsi = dsi;
396 
397 	return 0;
398 
399 err_dsi_attach:
400 	mipi_dsi_device_unregister(dsi);
401 err_dsi_host:
402 	drm_connector_cleanup(&pdata->connector);
403 	return ret;
404 }
405 
406 static void ti_sn_bridge_disable(struct drm_bridge *bridge)
407 {
408 	struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
409 
410 	drm_panel_disable(pdata->panel);
411 
412 	/* disable video stream */
413 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE, 0);
414 	/* semi auto link training mode OFF */
415 	regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0);
416 	/* disable DP PLL */
417 	regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
418 
419 	drm_panel_unprepare(pdata->panel);
420 }
421 
422 static u32 ti_sn_bridge_get_dsi_freq(struct ti_sn_bridge *pdata)
423 {
424 	u32 bit_rate_khz, clk_freq_khz;
425 	struct drm_display_mode *mode =
426 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
427 
428 	bit_rate_khz = mode->clock *
429 			mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
430 	clk_freq_khz = bit_rate_khz / (pdata->dsi->lanes * 2);
431 
432 	return clk_freq_khz;
433 }
434 
435 /* clk frequencies supported by bridge in Hz in case derived from REFCLK pin */
436 static const u32 ti_sn_bridge_refclk_lut[] = {
437 	12000000,
438 	19200000,
439 	26000000,
440 	27000000,
441 	38400000,
442 };
443 
444 /* clk frequencies supported by bridge in Hz in case derived from DACP/N pin */
445 static const u32 ti_sn_bridge_dsiclk_lut[] = {
446 	468000000,
447 	384000000,
448 	416000000,
449 	486000000,
450 	460800000,
451 };
452 
453 static void ti_sn_bridge_set_refclk_freq(struct ti_sn_bridge *pdata)
454 {
455 	int i;
456 	u32 refclk_rate;
457 	const u32 *refclk_lut;
458 	size_t refclk_lut_size;
459 
460 	if (pdata->refclk) {
461 		refclk_rate = clk_get_rate(pdata->refclk);
462 		refclk_lut = ti_sn_bridge_refclk_lut;
463 		refclk_lut_size = ARRAY_SIZE(ti_sn_bridge_refclk_lut);
464 		clk_prepare_enable(pdata->refclk);
465 	} else {
466 		refclk_rate = ti_sn_bridge_get_dsi_freq(pdata) * 1000;
467 		refclk_lut = ti_sn_bridge_dsiclk_lut;
468 		refclk_lut_size = ARRAY_SIZE(ti_sn_bridge_dsiclk_lut);
469 	}
470 
471 	/* for i equals to refclk_lut_size means default frequency */
472 	for (i = 0; i < refclk_lut_size; i++)
473 		if (refclk_lut[i] == refclk_rate)
474 			break;
475 
476 	regmap_update_bits(pdata->regmap, SN_DPPLL_SRC_REG, REFCLK_FREQ_MASK,
477 			   REFCLK_FREQ(i));
478 }
479 
480 static void ti_sn_bridge_set_dsi_rate(struct ti_sn_bridge *pdata)
481 {
482 	unsigned int bit_rate_mhz, clk_freq_mhz;
483 	unsigned int val;
484 	struct drm_display_mode *mode =
485 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
486 
487 	/* set DSIA clk frequency */
488 	bit_rate_mhz = (mode->clock / 1000) *
489 			mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
490 	clk_freq_mhz = bit_rate_mhz / (pdata->dsi->lanes * 2);
491 
492 	/* for each increment in val, frequency increases by 5MHz */
493 	val = (MIN_DSI_CLK_FREQ_MHZ / 5) +
494 		(((clk_freq_mhz - MIN_DSI_CLK_FREQ_MHZ) / 5) & 0xFF);
495 	regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val);
496 }
497 
498 static unsigned int ti_sn_bridge_get_bpp(struct ti_sn_bridge *pdata)
499 {
500 	if (pdata->connector.display_info.bpc <= 6)
501 		return 18;
502 	else
503 		return 24;
504 }
505 
506 /*
507  * LUT index corresponds to register value and
508  * LUT values corresponds to dp data rate supported
509  * by the bridge in Mbps unit.
510  */
511 static const unsigned int ti_sn_bridge_dp_rate_lut[] = {
512 	0, 1620, 2160, 2430, 2700, 3240, 4320, 5400
513 };
514 
515 static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn_bridge *pdata)
516 {
517 	unsigned int bit_rate_khz, dp_rate_mhz;
518 	unsigned int i;
519 	struct drm_display_mode *mode =
520 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
521 
522 	/* Calculate minimum bit rate based on our pixel clock. */
523 	bit_rate_khz = mode->clock * ti_sn_bridge_get_bpp(pdata);
524 
525 	/* Calculate minimum DP data rate, taking 80% as per DP spec */
526 	dp_rate_mhz = DIV_ROUND_UP(bit_rate_khz * DP_CLK_FUDGE_NUM,
527 				   1000 * pdata->dp_lanes * DP_CLK_FUDGE_DEN);
528 
529 	for (i = 1; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++)
530 		if (ti_sn_bridge_dp_rate_lut[i] >= dp_rate_mhz)
531 			break;
532 
533 	return i;
534 }
535 
536 static void ti_sn_bridge_read_valid_rates(struct ti_sn_bridge *pdata,
537 					  bool rate_valid[])
538 {
539 	unsigned int rate_per_200khz;
540 	unsigned int rate_mhz;
541 	u8 dpcd_val;
542 	int ret;
543 	int i, j;
544 
545 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_EDP_DPCD_REV, &dpcd_val);
546 	if (ret != 1) {
547 		DRM_DEV_ERROR(pdata->dev,
548 			      "Can't read eDP rev (%d), assuming 1.1\n", ret);
549 		dpcd_val = DP_EDP_11;
550 	}
551 
552 	if (dpcd_val >= DP_EDP_14) {
553 		/* eDP 1.4 devices must provide a custom table */
554 		__le16 sink_rates[DP_MAX_SUPPORTED_RATES];
555 
556 		ret = drm_dp_dpcd_read(&pdata->aux, DP_SUPPORTED_LINK_RATES,
557 				       sink_rates, sizeof(sink_rates));
558 
559 		if (ret != sizeof(sink_rates)) {
560 			DRM_DEV_ERROR(pdata->dev,
561 				"Can't read supported rate table (%d)\n", ret);
562 
563 			/* By zeroing we'll fall back to DP_MAX_LINK_RATE. */
564 			memset(sink_rates, 0, sizeof(sink_rates));
565 		}
566 
567 		for (i = 0; i < ARRAY_SIZE(sink_rates); i++) {
568 			rate_per_200khz = le16_to_cpu(sink_rates[i]);
569 
570 			if (!rate_per_200khz)
571 				break;
572 
573 			rate_mhz = rate_per_200khz * 200 / 1000;
574 			for (j = 0;
575 			     j < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
576 			     j++) {
577 				if (ti_sn_bridge_dp_rate_lut[j] == rate_mhz)
578 					rate_valid[j] = true;
579 			}
580 		}
581 
582 		for (i = 0; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut); i++) {
583 			if (rate_valid[i])
584 				return;
585 		}
586 		DRM_DEV_ERROR(pdata->dev,
587 			      "No matching eDP rates in table; falling back\n");
588 	}
589 
590 	/* On older versions best we can do is use DP_MAX_LINK_RATE */
591 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LINK_RATE, &dpcd_val);
592 	if (ret != 1) {
593 		DRM_DEV_ERROR(pdata->dev,
594 			      "Can't read max rate (%d); assuming 5.4 GHz\n",
595 			      ret);
596 		dpcd_val = DP_LINK_BW_5_4;
597 	}
598 
599 	switch (dpcd_val) {
600 	default:
601 		DRM_DEV_ERROR(pdata->dev,
602 			      "Unexpected max rate (%#x); assuming 5.4 GHz\n",
603 			      (int)dpcd_val);
604 		fallthrough;
605 	case DP_LINK_BW_5_4:
606 		rate_valid[7] = 1;
607 		fallthrough;
608 	case DP_LINK_BW_2_7:
609 		rate_valid[4] = 1;
610 		fallthrough;
611 	case DP_LINK_BW_1_62:
612 		rate_valid[1] = 1;
613 		break;
614 	}
615 }
616 
617 static void ti_sn_bridge_set_video_timings(struct ti_sn_bridge *pdata)
618 {
619 	struct drm_display_mode *mode =
620 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
621 	u8 hsync_polarity = 0, vsync_polarity = 0;
622 
623 	if (mode->flags & DRM_MODE_FLAG_PHSYNC)
624 		hsync_polarity = CHA_HSYNC_POLARITY;
625 	if (mode->flags & DRM_MODE_FLAG_PVSYNC)
626 		vsync_polarity = CHA_VSYNC_POLARITY;
627 
628 	ti_sn_bridge_write_u16(pdata, SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG,
629 			       mode->hdisplay);
630 	ti_sn_bridge_write_u16(pdata, SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG,
631 			       mode->vdisplay);
632 	regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG,
633 		     (mode->hsync_end - mode->hsync_start) & 0xFF);
634 	regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_HIGH_REG,
635 		     (((mode->hsync_end - mode->hsync_start) >> 8) & 0x7F) |
636 		     hsync_polarity);
637 	regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG,
638 		     (mode->vsync_end - mode->vsync_start) & 0xFF);
639 	regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_HIGH_REG,
640 		     (((mode->vsync_end - mode->vsync_start) >> 8) & 0x7F) |
641 		     vsync_polarity);
642 
643 	regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_BACK_PORCH_REG,
644 		     (mode->htotal - mode->hsync_end) & 0xFF);
645 	regmap_write(pdata->regmap, SN_CHA_VERTICAL_BACK_PORCH_REG,
646 		     (mode->vtotal - mode->vsync_end) & 0xFF);
647 
648 	regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_FRONT_PORCH_REG,
649 		     (mode->hsync_start - mode->hdisplay) & 0xFF);
650 	regmap_write(pdata->regmap, SN_CHA_VERTICAL_FRONT_PORCH_REG,
651 		     (mode->vsync_start - mode->vdisplay) & 0xFF);
652 
653 	usleep_range(10000, 10500); /* 10ms delay recommended by spec */
654 }
655 
656 static unsigned int ti_sn_get_max_lanes(struct ti_sn_bridge *pdata)
657 {
658 	u8 data;
659 	int ret;
660 
661 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LANE_COUNT, &data);
662 	if (ret != 1) {
663 		DRM_DEV_ERROR(pdata->dev,
664 			      "Can't read lane count (%d); assuming 4\n", ret);
665 		return 4;
666 	}
667 
668 	return data & DP_LANE_COUNT_MASK;
669 }
670 
671 static int ti_sn_link_training(struct ti_sn_bridge *pdata, int dp_rate_idx,
672 			       const char **last_err_str)
673 {
674 	unsigned int val;
675 	int ret;
676 
677 	/* set dp clk frequency value */
678 	regmap_update_bits(pdata->regmap, SN_DATARATE_CONFIG_REG,
679 			   DP_DATARATE_MASK, DP_DATARATE(dp_rate_idx));
680 
681 	/* enable DP PLL */
682 	regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
683 
684 	ret = regmap_read_poll_timeout(pdata->regmap, SN_DPPLL_SRC_REG, val,
685 				       val & DPPLL_SRC_DP_PLL_LOCK, 1000,
686 				       50 * 1000);
687 	if (ret) {
688 		*last_err_str = "DP_PLL_LOCK polling failed";
689 		goto exit;
690 	}
691 
692 	/* Semi auto link training mode */
693 	regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A);
694 	ret = regmap_read_poll_timeout(pdata->regmap, SN_ML_TX_MODE_REG, val,
695 				       val == ML_TX_MAIN_LINK_OFF ||
696 				       val == ML_TX_NORMAL_MODE, 1000,
697 				       500 * 1000);
698 	if (ret) {
699 		*last_err_str = "Training complete polling failed";
700 	} else if (val == ML_TX_MAIN_LINK_OFF) {
701 		*last_err_str = "Link training failed, link is off";
702 		ret = -EIO;
703 	}
704 
705 exit:
706 	/* Disable the PLL if we failed */
707 	if (ret)
708 		regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
709 
710 	return ret;
711 }
712 
713 static void ti_sn_bridge_enable(struct drm_bridge *bridge)
714 {
715 	struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
716 	bool rate_valid[ARRAY_SIZE(ti_sn_bridge_dp_rate_lut)] = { };
717 	const char *last_err_str = "No supported DP rate";
718 	int dp_rate_idx;
719 	unsigned int val;
720 	int ret = -EINVAL;
721 	int max_dp_lanes;
722 
723 	max_dp_lanes = ti_sn_get_max_lanes(pdata);
724 	pdata->dp_lanes = min(pdata->dp_lanes, max_dp_lanes);
725 
726 	/* DSI_A lane config */
727 	val = CHA_DSI_LANES(SN_MAX_DP_LANES - pdata->dsi->lanes);
728 	regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG,
729 			   CHA_DSI_LANES_MASK, val);
730 
731 	regmap_write(pdata->regmap, SN_LN_ASSIGN_REG, pdata->ln_assign);
732 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, LN_POLRS_MASK,
733 			   pdata->ln_polrs << LN_POLRS_OFFSET);
734 
735 	/* set dsi clk frequency value */
736 	ti_sn_bridge_set_dsi_rate(pdata);
737 
738 	/**
739 	 * The SN65DSI86 only supports ASSR Display Authentication method and
740 	 * this method is enabled by default. An eDP panel must support this
741 	 * authentication method. We need to enable this method in the eDP panel
742 	 * at DisplayPort address 0x0010A prior to link training.
743 	 */
744 	drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET,
745 			   DP_ALTERNATE_SCRAMBLER_RESET_ENABLE);
746 
747 	/* Set the DP output format (18 bpp or 24 bpp) */
748 	val = (ti_sn_bridge_get_bpp(pdata) == 18) ? BPP_18_RGB : 0;
749 	regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val);
750 
751 	/* DP lane config */
752 	val = DP_NUM_LANES(min(pdata->dp_lanes, 3));
753 	regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK,
754 			   val);
755 
756 	ti_sn_bridge_read_valid_rates(pdata, rate_valid);
757 
758 	/* Train until we run out of rates */
759 	for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata);
760 	     dp_rate_idx < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
761 	     dp_rate_idx++) {
762 		if (!rate_valid[dp_rate_idx])
763 			continue;
764 
765 		ret = ti_sn_link_training(pdata, dp_rate_idx, &last_err_str);
766 		if (!ret)
767 			break;
768 	}
769 	if (ret) {
770 		DRM_DEV_ERROR(pdata->dev, "%s (%d)\n", last_err_str, ret);
771 		return;
772 	}
773 
774 	/* config video parameters */
775 	ti_sn_bridge_set_video_timings(pdata);
776 
777 	/* enable video stream */
778 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE,
779 			   VSTREAM_ENABLE);
780 
781 	drm_panel_enable(pdata->panel);
782 }
783 
784 static void ti_sn_bridge_pre_enable(struct drm_bridge *bridge)
785 {
786 	struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
787 
788 	pm_runtime_get_sync(pdata->dev);
789 
790 	/* configure bridge ref_clk */
791 	ti_sn_bridge_set_refclk_freq(pdata);
792 
793 	/*
794 	 * HPD on this bridge chip is a bit useless.  This is an eDP bridge
795 	 * so the HPD is an internal signal that's only there to signal that
796 	 * the panel is done powering up.  ...but the bridge chip debounces
797 	 * this signal by between 100 ms and 400 ms (depending on process,
798 	 * voltage, and temperate--I measured it at about 200 ms).  One
799 	 * particular panel asserted HPD 84 ms after it was powered on meaning
800 	 * that we saw HPD 284 ms after power on.  ...but the same panel said
801 	 * that instead of looking at HPD you could just hardcode a delay of
802 	 * 200 ms.  We'll assume that the panel driver will have the hardcoded
803 	 * delay in its prepare and always disable HPD.
804 	 *
805 	 * If HPD somehow makes sense on some future panel we'll have to
806 	 * change this to be conditional on someone specifying that HPD should
807 	 * be used.
808 	 */
809 	regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE,
810 			   HPD_DISABLE);
811 
812 	drm_panel_prepare(pdata->panel);
813 }
814 
815 static void ti_sn_bridge_post_disable(struct drm_bridge *bridge)
816 {
817 	struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
818 
819 	if (pdata->refclk)
820 		clk_disable_unprepare(pdata->refclk);
821 
822 	pm_runtime_put_sync(pdata->dev);
823 }
824 
825 static const struct drm_bridge_funcs ti_sn_bridge_funcs = {
826 	.attach = ti_sn_bridge_attach,
827 	.pre_enable = ti_sn_bridge_pre_enable,
828 	.enable = ti_sn_bridge_enable,
829 	.disable = ti_sn_bridge_disable,
830 	.post_disable = ti_sn_bridge_post_disable,
831 };
832 
833 static struct ti_sn_bridge *aux_to_ti_sn_bridge(struct drm_dp_aux *aux)
834 {
835 	return container_of(aux, struct ti_sn_bridge, aux);
836 }
837 
838 static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux,
839 				  struct drm_dp_aux_msg *msg)
840 {
841 	struct ti_sn_bridge *pdata = aux_to_ti_sn_bridge(aux);
842 	u32 request = msg->request & ~DP_AUX_I2C_MOT;
843 	u32 request_val = AUX_CMD_REQ(msg->request);
844 	u8 *buf = (u8 *)msg->buffer;
845 	unsigned int val;
846 	int ret, i;
847 
848 	if (msg->size > SN_AUX_MAX_PAYLOAD_BYTES)
849 		return -EINVAL;
850 
851 	switch (request) {
852 	case DP_AUX_NATIVE_WRITE:
853 	case DP_AUX_I2C_WRITE:
854 	case DP_AUX_NATIVE_READ:
855 	case DP_AUX_I2C_READ:
856 		regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val);
857 		break;
858 	default:
859 		return -EINVAL;
860 	}
861 
862 	regmap_write(pdata->regmap, SN_AUX_ADDR_19_16_REG,
863 		     (msg->address >> 16) & 0xF);
864 	regmap_write(pdata->regmap, SN_AUX_ADDR_15_8_REG,
865 		     (msg->address >> 8) & 0xFF);
866 	regmap_write(pdata->regmap, SN_AUX_ADDR_7_0_REG, msg->address & 0xFF);
867 
868 	regmap_write(pdata->regmap, SN_AUX_LENGTH_REG, msg->size);
869 
870 	if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE) {
871 		for (i = 0; i < msg->size; i++)
872 			regmap_write(pdata->regmap, SN_AUX_WDATA_REG(i),
873 				     buf[i]);
874 	}
875 
876 	/* Clear old status bits before start so we don't get confused */
877 	regmap_write(pdata->regmap, SN_AUX_CMD_STATUS_REG,
878 		     AUX_IRQ_STATUS_NAT_I2C_FAIL |
879 		     AUX_IRQ_STATUS_AUX_RPLY_TOUT |
880 		     AUX_IRQ_STATUS_AUX_SHORT);
881 
882 	regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val | AUX_CMD_SEND);
883 
884 	ret = regmap_read_poll_timeout(pdata->regmap, SN_AUX_CMD_REG, val,
885 				       !(val & AUX_CMD_SEND), 200,
886 				       50 * 1000);
887 	if (ret)
888 		return ret;
889 
890 	ret = regmap_read(pdata->regmap, SN_AUX_CMD_STATUS_REG, &val);
891 	if (ret)
892 		return ret;
893 	else if ((val & AUX_IRQ_STATUS_NAT_I2C_FAIL)
894 		 || (val & AUX_IRQ_STATUS_AUX_RPLY_TOUT)
895 		 || (val & AUX_IRQ_STATUS_AUX_SHORT))
896 		return -ENXIO;
897 
898 	if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE)
899 		return msg->size;
900 
901 	for (i = 0; i < msg->size; i++) {
902 		unsigned int val;
903 		ret = regmap_read(pdata->regmap, SN_AUX_RDATA_REG(i),
904 				  &val);
905 		if (ret)
906 			return ret;
907 
908 		WARN_ON(val & ~0xFF);
909 		buf[i] = (u8)(val & 0xFF);
910 	}
911 
912 	return msg->size;
913 }
914 
915 static int ti_sn_bridge_parse_dsi_host(struct ti_sn_bridge *pdata)
916 {
917 	struct device_node *np = pdata->dev->of_node;
918 
919 	pdata->host_node = of_graph_get_remote_node(np, 0, 0);
920 
921 	if (!pdata->host_node) {
922 		DRM_ERROR("remote dsi host node not found\n");
923 		return -ENODEV;
924 	}
925 
926 	return 0;
927 }
928 
929 #if defined(CONFIG_OF_GPIO)
930 
931 static int tn_sn_bridge_of_xlate(struct gpio_chip *chip,
932 				 const struct of_phandle_args *gpiospec,
933 				 u32 *flags)
934 {
935 	if (WARN_ON(gpiospec->args_count < chip->of_gpio_n_cells))
936 		return -EINVAL;
937 
938 	if (gpiospec->args[0] > chip->ngpio || gpiospec->args[0] < 1)
939 		return -EINVAL;
940 
941 	if (flags)
942 		*flags = gpiospec->args[1];
943 
944 	return gpiospec->args[0] - SN_GPIO_PHYSICAL_OFFSET;
945 }
946 
947 static int ti_sn_bridge_gpio_get_direction(struct gpio_chip *chip,
948 					   unsigned int offset)
949 {
950 	struct ti_sn_bridge *pdata = gpiochip_get_data(chip);
951 
952 	/*
953 	 * We already have to keep track of the direction because we use
954 	 * that to figure out whether we've powered the device.  We can
955 	 * just return that rather than (maybe) powering up the device
956 	 * to ask its direction.
957 	 */
958 	return test_bit(offset, pdata->gchip_output) ?
959 		GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
960 }
961 
962 static int ti_sn_bridge_gpio_get(struct gpio_chip *chip, unsigned int offset)
963 {
964 	struct ti_sn_bridge *pdata = gpiochip_get_data(chip);
965 	unsigned int val;
966 	int ret;
967 
968 	/*
969 	 * When the pin is an input we don't forcibly keep the bridge
970 	 * powered--we just power it on to read the pin.  NOTE: part of
971 	 * the reason this works is that the bridge defaults (when
972 	 * powered back on) to all 4 GPIOs being configured as GPIO input.
973 	 * Also note that if something else is keeping the chip powered the
974 	 * pm_runtime functions are lightweight increments of a refcount.
975 	 */
976 	pm_runtime_get_sync(pdata->dev);
977 	ret = regmap_read(pdata->regmap, SN_GPIO_IO_REG, &val);
978 	pm_runtime_put(pdata->dev);
979 
980 	if (ret)
981 		return ret;
982 
983 	return !!(val & BIT(SN_GPIO_INPUT_SHIFT + offset));
984 }
985 
986 static void ti_sn_bridge_gpio_set(struct gpio_chip *chip, unsigned int offset,
987 				  int val)
988 {
989 	struct ti_sn_bridge *pdata = gpiochip_get_data(chip);
990 	int ret;
991 
992 	if (!test_bit(offset, pdata->gchip_output)) {
993 		dev_err(pdata->dev, "Ignoring GPIO set while input\n");
994 		return;
995 	}
996 
997 	val &= 1;
998 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_IO_REG,
999 				 BIT(SN_GPIO_OUTPUT_SHIFT + offset),
1000 				 val << (SN_GPIO_OUTPUT_SHIFT + offset));
1001 	if (ret)
1002 		dev_warn(pdata->dev,
1003 			 "Failed to set bridge GPIO %u: %d\n", offset, ret);
1004 }
1005 
1006 static int ti_sn_bridge_gpio_direction_input(struct gpio_chip *chip,
1007 					     unsigned int offset)
1008 {
1009 	struct ti_sn_bridge *pdata = gpiochip_get_data(chip);
1010 	int shift = offset * 2;
1011 	int ret;
1012 
1013 	if (!test_and_clear_bit(offset, pdata->gchip_output))
1014 		return 0;
1015 
1016 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1017 				 SN_GPIO_MUX_MASK << shift,
1018 				 SN_GPIO_MUX_INPUT << shift);
1019 	if (ret) {
1020 		set_bit(offset, pdata->gchip_output);
1021 		return ret;
1022 	}
1023 
1024 	/*
1025 	 * NOTE: if nobody else is powering the device this may fully power
1026 	 * it off and when it comes back it will have lost all state, but
1027 	 * that's OK because the default is input and we're now an input.
1028 	 */
1029 	pm_runtime_put(pdata->dev);
1030 
1031 	return 0;
1032 }
1033 
1034 static int ti_sn_bridge_gpio_direction_output(struct gpio_chip *chip,
1035 					      unsigned int offset, int val)
1036 {
1037 	struct ti_sn_bridge *pdata = gpiochip_get_data(chip);
1038 	int shift = offset * 2;
1039 	int ret;
1040 
1041 	if (test_and_set_bit(offset, pdata->gchip_output))
1042 		return 0;
1043 
1044 	pm_runtime_get_sync(pdata->dev);
1045 
1046 	/* Set value first to avoid glitching */
1047 	ti_sn_bridge_gpio_set(chip, offset, val);
1048 
1049 	/* Set direction */
1050 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1051 				 SN_GPIO_MUX_MASK << shift,
1052 				 SN_GPIO_MUX_OUTPUT << shift);
1053 	if (ret) {
1054 		clear_bit(offset, pdata->gchip_output);
1055 		pm_runtime_put(pdata->dev);
1056 	}
1057 
1058 	return ret;
1059 }
1060 
1061 static void ti_sn_bridge_gpio_free(struct gpio_chip *chip, unsigned int offset)
1062 {
1063 	/* We won't keep pm_runtime if we're input, so switch there on free */
1064 	ti_sn_bridge_gpio_direction_input(chip, offset);
1065 }
1066 
1067 static const char * const ti_sn_bridge_gpio_names[SN_NUM_GPIOS] = {
1068 	"GPIO1", "GPIO2", "GPIO3", "GPIO4"
1069 };
1070 
1071 static int ti_sn_setup_gpio_controller(struct ti_sn_bridge *pdata)
1072 {
1073 	int ret;
1074 
1075 	/* Only init if someone is going to use us as a GPIO controller */
1076 	if (!of_property_read_bool(pdata->dev->of_node, "gpio-controller"))
1077 		return 0;
1078 
1079 	pdata->gchip.label = dev_name(pdata->dev);
1080 	pdata->gchip.parent = pdata->dev;
1081 	pdata->gchip.owner = THIS_MODULE;
1082 	pdata->gchip.of_xlate = tn_sn_bridge_of_xlate;
1083 	pdata->gchip.of_gpio_n_cells = 2;
1084 	pdata->gchip.free = ti_sn_bridge_gpio_free;
1085 	pdata->gchip.get_direction = ti_sn_bridge_gpio_get_direction;
1086 	pdata->gchip.direction_input = ti_sn_bridge_gpio_direction_input;
1087 	pdata->gchip.direction_output = ti_sn_bridge_gpio_direction_output;
1088 	pdata->gchip.get = ti_sn_bridge_gpio_get;
1089 	pdata->gchip.set = ti_sn_bridge_gpio_set;
1090 	pdata->gchip.can_sleep = true;
1091 	pdata->gchip.names = ti_sn_bridge_gpio_names;
1092 	pdata->gchip.ngpio = SN_NUM_GPIOS;
1093 	pdata->gchip.base = -1;
1094 	ret = devm_gpiochip_add_data(pdata->dev, &pdata->gchip, pdata);
1095 	if (ret)
1096 		dev_err(pdata->dev, "can't add gpio chip\n");
1097 
1098 	return ret;
1099 }
1100 
1101 #else
1102 
1103 static inline int ti_sn_setup_gpio_controller(struct ti_sn_bridge *pdata)
1104 {
1105 	return 0;
1106 }
1107 
1108 #endif
1109 
1110 static void ti_sn_bridge_parse_lanes(struct ti_sn_bridge *pdata,
1111 				     struct device_node *np)
1112 {
1113 	u32 lane_assignments[SN_MAX_DP_LANES] = { 0, 1, 2, 3 };
1114 	u32 lane_polarities[SN_MAX_DP_LANES] = { };
1115 	struct device_node *endpoint;
1116 	u8 ln_assign = 0;
1117 	u8 ln_polrs = 0;
1118 	int dp_lanes;
1119 	int i;
1120 
1121 	/*
1122 	 * Read config from the device tree about lane remapping and lane
1123 	 * polarities.  These are optional and we assume identity map and
1124 	 * normal polarity if nothing is specified.  It's OK to specify just
1125 	 * data-lanes but not lane-polarities but not vice versa.
1126 	 *
1127 	 * Error checking is light (we just make sure we don't crash or
1128 	 * buffer overrun) and we assume dts is well formed and specifying
1129 	 * mappings that the hardware supports.
1130 	 */
1131 	endpoint = of_graph_get_endpoint_by_regs(np, 1, -1);
1132 	dp_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
1133 	if (dp_lanes > 0 && dp_lanes <= SN_MAX_DP_LANES) {
1134 		of_property_read_u32_array(endpoint, "data-lanes",
1135 					   lane_assignments, dp_lanes);
1136 		of_property_read_u32_array(endpoint, "lane-polarities",
1137 					   lane_polarities, dp_lanes);
1138 	} else {
1139 		dp_lanes = SN_MAX_DP_LANES;
1140 	}
1141 	of_node_put(endpoint);
1142 
1143 	/*
1144 	 * Convert into register format.  Loop over all lanes even if
1145 	 * data-lanes had fewer elements so that we nicely initialize
1146 	 * the LN_ASSIGN register.
1147 	 */
1148 	for (i = SN_MAX_DP_LANES - 1; i >= 0; i--) {
1149 		ln_assign = ln_assign << LN_ASSIGN_WIDTH | lane_assignments[i];
1150 		ln_polrs = ln_polrs << 1 | lane_polarities[i];
1151 	}
1152 
1153 	/* Stash in our struct for when we power on */
1154 	pdata->dp_lanes = dp_lanes;
1155 	pdata->ln_assign = ln_assign;
1156 	pdata->ln_polrs = ln_polrs;
1157 }
1158 
1159 static int ti_sn_bridge_probe(struct i2c_client *client,
1160 			      const struct i2c_device_id *id)
1161 {
1162 	struct ti_sn_bridge *pdata;
1163 	int ret;
1164 
1165 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1166 		DRM_ERROR("device doesn't support I2C\n");
1167 		return -ENODEV;
1168 	}
1169 
1170 	pdata = devm_kzalloc(&client->dev, sizeof(struct ti_sn_bridge),
1171 			     GFP_KERNEL);
1172 	if (!pdata)
1173 		return -ENOMEM;
1174 
1175 	pdata->regmap = devm_regmap_init_i2c(client,
1176 					     &ti_sn_bridge_regmap_config);
1177 	if (IS_ERR(pdata->regmap)) {
1178 		DRM_ERROR("regmap i2c init failed\n");
1179 		return PTR_ERR(pdata->regmap);
1180 	}
1181 
1182 	pdata->dev = &client->dev;
1183 
1184 	ret = drm_of_find_panel_or_bridge(pdata->dev->of_node, 1, 0,
1185 					  &pdata->panel, NULL);
1186 	if (ret) {
1187 		DRM_ERROR("could not find any panel node\n");
1188 		return ret;
1189 	}
1190 
1191 	dev_set_drvdata(&client->dev, pdata);
1192 
1193 	pdata->enable_gpio = devm_gpiod_get(pdata->dev, "enable",
1194 					    GPIOD_OUT_LOW);
1195 	if (IS_ERR(pdata->enable_gpio)) {
1196 		DRM_ERROR("failed to get enable gpio from DT\n");
1197 		ret = PTR_ERR(pdata->enable_gpio);
1198 		return ret;
1199 	}
1200 
1201 	ti_sn_bridge_parse_lanes(pdata, client->dev.of_node);
1202 
1203 	ret = ti_sn_bridge_parse_regulators(pdata);
1204 	if (ret) {
1205 		DRM_ERROR("failed to parse regulators\n");
1206 		return ret;
1207 	}
1208 
1209 	pdata->refclk = devm_clk_get(pdata->dev, "refclk");
1210 	if (IS_ERR(pdata->refclk)) {
1211 		ret = PTR_ERR(pdata->refclk);
1212 		if (ret == -EPROBE_DEFER)
1213 			return ret;
1214 		DRM_DEBUG_KMS("refclk not found\n");
1215 		pdata->refclk = NULL;
1216 	}
1217 
1218 	ret = ti_sn_bridge_parse_dsi_host(pdata);
1219 	if (ret)
1220 		return ret;
1221 
1222 	pm_runtime_enable(pdata->dev);
1223 
1224 	ret = ti_sn_setup_gpio_controller(pdata);
1225 	if (ret) {
1226 		pm_runtime_disable(pdata->dev);
1227 		return ret;
1228 	}
1229 
1230 	i2c_set_clientdata(client, pdata);
1231 
1232 	pdata->aux.name = "ti-sn65dsi86-aux";
1233 	pdata->aux.dev = pdata->dev;
1234 	pdata->aux.transfer = ti_sn_aux_transfer;
1235 	drm_dp_aux_register(&pdata->aux);
1236 
1237 	pdata->bridge.funcs = &ti_sn_bridge_funcs;
1238 	pdata->bridge.of_node = client->dev.of_node;
1239 
1240 	drm_bridge_add(&pdata->bridge);
1241 
1242 	ti_sn_debugfs_init(pdata);
1243 
1244 	return 0;
1245 }
1246 
1247 static int ti_sn_bridge_remove(struct i2c_client *client)
1248 {
1249 	struct ti_sn_bridge *pdata = i2c_get_clientdata(client);
1250 
1251 	if (!pdata)
1252 		return -EINVAL;
1253 
1254 	ti_sn_debugfs_remove(pdata);
1255 
1256 	of_node_put(pdata->host_node);
1257 
1258 	pm_runtime_disable(pdata->dev);
1259 
1260 	if (pdata->dsi) {
1261 		mipi_dsi_detach(pdata->dsi);
1262 		mipi_dsi_device_unregister(pdata->dsi);
1263 	}
1264 
1265 	drm_bridge_remove(&pdata->bridge);
1266 
1267 	return 0;
1268 }
1269 
1270 static struct i2c_device_id ti_sn_bridge_id[] = {
1271 	{ "ti,sn65dsi86", 0},
1272 	{},
1273 };
1274 MODULE_DEVICE_TABLE(i2c, ti_sn_bridge_id);
1275 
1276 static const struct of_device_id ti_sn_bridge_match_table[] = {
1277 	{.compatible = "ti,sn65dsi86"},
1278 	{},
1279 };
1280 MODULE_DEVICE_TABLE(of, ti_sn_bridge_match_table);
1281 
1282 static struct i2c_driver ti_sn_bridge_driver = {
1283 	.driver = {
1284 		.name = "ti_sn65dsi86",
1285 		.of_match_table = ti_sn_bridge_match_table,
1286 		.pm = &ti_sn_bridge_pm_ops,
1287 	},
1288 	.probe = ti_sn_bridge_probe,
1289 	.remove = ti_sn_bridge_remove,
1290 	.id_table = ti_sn_bridge_id,
1291 };
1292 module_i2c_driver(ti_sn_bridge_driver);
1293 
1294 MODULE_AUTHOR("Sandeep Panda <spanda@codeaurora.org>");
1295 MODULE_DESCRIPTION("sn65dsi86 DSI to eDP bridge driver");
1296 MODULE_LICENSE("GPL v2");
1297