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/atomic.h>
8 #include <linux/auxiliary_bus.h>
9 #include <linux/bitfield.h>
10 #include <linux/bits.h>
11 #include <linux/clk.h>
12 #include <linux/debugfs.h>
13 #include <linux/gpio/consumer.h>
14 #include <linux/gpio/driver.h>
15 #include <linux/i2c.h>
16 #include <linux/iopoll.h>
17 #include <linux/module.h>
18 #include <linux/of_graph.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/pwm.h>
21 #include <linux/regmap.h>
22 #include <linux/regulator/consumer.h>
23 
24 #include <asm/unaligned.h>
25 
26 #include <drm/drm_atomic.h>
27 #include <drm/drm_atomic_helper.h>
28 #include <drm/drm_bridge.h>
29 #include <drm/drm_bridge_connector.h>
30 #include <drm/dp/drm_dp_aux_bus.h>
31 #include <drm/dp/drm_dp_helper.h>
32 #include <drm/drm_mipi_dsi.h>
33 #include <drm/drm_of.h>
34 #include <drm/drm_panel.h>
35 #include <drm/drm_print.h>
36 #include <drm/drm_probe_helper.h>
37 
38 #define SN_DEVICE_REV_REG			0x08
39 #define SN_DPPLL_SRC_REG			0x0A
40 #define  DPPLL_CLK_SRC_DSICLK			BIT(0)
41 #define  REFCLK_FREQ_MASK			GENMASK(3, 1)
42 #define  REFCLK_FREQ(x)				((x) << 1)
43 #define  DPPLL_SRC_DP_PLL_LOCK			BIT(7)
44 #define SN_PLL_ENABLE_REG			0x0D
45 #define SN_DSI_LANES_REG			0x10
46 #define  CHA_DSI_LANES_MASK			GENMASK(4, 3)
47 #define  CHA_DSI_LANES(x)			((x) << 3)
48 #define SN_DSIA_CLK_FREQ_REG			0x12
49 #define SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG	0x20
50 #define SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG	0x24
51 #define SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG	0x2C
52 #define SN_CHA_HSYNC_PULSE_WIDTH_HIGH_REG	0x2D
53 #define  CHA_HSYNC_POLARITY			BIT(7)
54 #define SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG	0x30
55 #define SN_CHA_VSYNC_PULSE_WIDTH_HIGH_REG	0x31
56 #define  CHA_VSYNC_POLARITY			BIT(7)
57 #define SN_CHA_HORIZONTAL_BACK_PORCH_REG	0x34
58 #define SN_CHA_VERTICAL_BACK_PORCH_REG		0x36
59 #define SN_CHA_HORIZONTAL_FRONT_PORCH_REG	0x38
60 #define SN_CHA_VERTICAL_FRONT_PORCH_REG		0x3A
61 #define SN_LN_ASSIGN_REG			0x59
62 #define  LN_ASSIGN_WIDTH			2
63 #define SN_ENH_FRAME_REG			0x5A
64 #define  VSTREAM_ENABLE				BIT(3)
65 #define  LN_POLRS_OFFSET			4
66 #define  LN_POLRS_MASK				0xf0
67 #define SN_DATA_FORMAT_REG			0x5B
68 #define  BPP_18_RGB				BIT(0)
69 #define SN_HPD_DISABLE_REG			0x5C
70 #define  HPD_DISABLE				BIT(0)
71 #define SN_GPIO_IO_REG				0x5E
72 #define  SN_GPIO_INPUT_SHIFT			4
73 #define  SN_GPIO_OUTPUT_SHIFT			0
74 #define SN_GPIO_CTRL_REG			0x5F
75 #define  SN_GPIO_MUX_INPUT			0
76 #define  SN_GPIO_MUX_OUTPUT			1
77 #define  SN_GPIO_MUX_SPECIAL			2
78 #define  SN_GPIO_MUX_MASK			0x3
79 #define SN_AUX_WDATA_REG(x)			(0x64 + (x))
80 #define SN_AUX_ADDR_19_16_REG			0x74
81 #define SN_AUX_ADDR_15_8_REG			0x75
82 #define SN_AUX_ADDR_7_0_REG			0x76
83 #define SN_AUX_ADDR_MASK			GENMASK(19, 0)
84 #define SN_AUX_LENGTH_REG			0x77
85 #define SN_AUX_CMD_REG				0x78
86 #define  AUX_CMD_SEND				BIT(0)
87 #define  AUX_CMD_REQ(x)				((x) << 4)
88 #define SN_AUX_RDATA_REG(x)			(0x79 + (x))
89 #define SN_SSC_CONFIG_REG			0x93
90 #define  DP_NUM_LANES_MASK			GENMASK(5, 4)
91 #define  DP_NUM_LANES(x)			((x) << 4)
92 #define SN_DATARATE_CONFIG_REG			0x94
93 #define  DP_DATARATE_MASK			GENMASK(7, 5)
94 #define  DP_DATARATE(x)				((x) << 5)
95 #define SN_ML_TX_MODE_REG			0x96
96 #define  ML_TX_MAIN_LINK_OFF			0
97 #define  ML_TX_NORMAL_MODE			BIT(0)
98 #define SN_PWM_PRE_DIV_REG			0xA0
99 #define SN_BACKLIGHT_SCALE_REG			0xA1
100 #define  BACKLIGHT_SCALE_MAX			0xFFFF
101 #define SN_BACKLIGHT_REG			0xA3
102 #define SN_PWM_EN_INV_REG			0xA5
103 #define  SN_PWM_INV_MASK			BIT(0)
104 #define  SN_PWM_EN_MASK				BIT(1)
105 #define SN_AUX_CMD_STATUS_REG			0xF4
106 #define  AUX_IRQ_STATUS_AUX_RPLY_TOUT		BIT(3)
107 #define  AUX_IRQ_STATUS_AUX_SHORT		BIT(5)
108 #define  AUX_IRQ_STATUS_NAT_I2C_FAIL		BIT(6)
109 
110 #define MIN_DSI_CLK_FREQ_MHZ	40
111 
112 /* fudge factor required to account for 8b/10b encoding */
113 #define DP_CLK_FUDGE_NUM	10
114 #define DP_CLK_FUDGE_DEN	8
115 
116 /* Matches DP_AUX_MAX_PAYLOAD_BYTES (for now) */
117 #define SN_AUX_MAX_PAYLOAD_BYTES	16
118 
119 #define SN_REGULATOR_SUPPLY_NUM		4
120 
121 #define SN_MAX_DP_LANES			4
122 #define SN_NUM_GPIOS			4
123 #define SN_GPIO_PHYSICAL_OFFSET		1
124 
125 #define SN_LINK_TRAINING_TRIES		10
126 
127 #define SN_PWM_GPIO_IDX			3 /* 4th GPIO */
128 
129 /**
130  * struct ti_sn65dsi86 - Platform data for ti-sn65dsi86 driver.
131  * @bridge_aux:   AUX-bus sub device for MIPI-to-eDP bridge functionality.
132  * @gpio_aux:     AUX-bus sub device for GPIO controller functionality.
133  * @aux_aux:      AUX-bus sub device for eDP AUX channel functionality.
134  * @pwm_aux:      AUX-bus sub device for PWM controller functionality.
135  *
136  * @dev:          Pointer to the top level (i2c) device.
137  * @regmap:       Regmap for accessing i2c.
138  * @aux:          Our aux channel.
139  * @bridge:       Our bridge.
140  * @connector:    Our connector.
141  * @host_node:    Remote DSI node.
142  * @dsi:          Our MIPI DSI source.
143  * @refclk:       Our reference clock.
144  * @next_bridge:  The bridge on the eDP side.
145  * @enable_gpio:  The GPIO we toggle to enable the bridge.
146  * @supplies:     Data for bulk enabling/disabling our regulators.
147  * @dp_lanes:     Count of dp_lanes we're using.
148  * @ln_assign:    Value to program to the LN_ASSIGN register.
149  * @ln_polrs:     Value for the 4-bit LN_POLRS field of SN_ENH_FRAME_REG.
150  * @comms_enabled: If true then communication over the aux channel is enabled.
151  * @comms_mutex:   Protects modification of comms_enabled.
152  *
153  * @gchip:        If we expose our GPIOs, this is used.
154  * @gchip_output: A cache of whether we've set GPIOs to output.  This
155  *                serves double-duty of keeping track of the direction and
156  *                also keeping track of whether we've incremented the
157  *                pm_runtime reference count for this pin, which we do
158  *                whenever a pin is configured as an output.  This is a
159  *                bitmap so we can do atomic ops on it without an extra
160  *                lock so concurrent users of our 4 GPIOs don't stomp on
161  *                each other's read-modify-write.
162  *
163  * @pchip:        pwm_chip if the PWM is exposed.
164  * @pwm_enabled:  Used to track if the PWM signal is currently enabled.
165  * @pwm_pin_busy: Track if GPIO4 is currently requested for GPIO or PWM.
166  * @pwm_refclk_freq: Cache for the reference clock input to the PWM.
167  */
168 struct ti_sn65dsi86 {
169 	struct auxiliary_device		bridge_aux;
170 	struct auxiliary_device		gpio_aux;
171 	struct auxiliary_device		aux_aux;
172 	struct auxiliary_device		pwm_aux;
173 
174 	struct device			*dev;
175 	struct regmap			*regmap;
176 	struct drm_dp_aux		aux;
177 	struct drm_bridge		bridge;
178 	struct drm_connector		*connector;
179 	struct device_node		*host_node;
180 	struct mipi_dsi_device		*dsi;
181 	struct clk			*refclk;
182 	struct drm_bridge		*next_bridge;
183 	struct gpio_desc		*enable_gpio;
184 	struct regulator_bulk_data	supplies[SN_REGULATOR_SUPPLY_NUM];
185 	int				dp_lanes;
186 	u8				ln_assign;
187 	u8				ln_polrs;
188 	bool				comms_enabled;
189 	struct mutex			comms_mutex;
190 
191 #if defined(CONFIG_OF_GPIO)
192 	struct gpio_chip		gchip;
193 	DECLARE_BITMAP(gchip_output, SN_NUM_GPIOS);
194 #endif
195 #if defined(CONFIG_PWM)
196 	struct pwm_chip			pchip;
197 	bool				pwm_enabled;
198 	atomic_t			pwm_pin_busy;
199 #endif
200 	unsigned int			pwm_refclk_freq;
201 };
202 
203 static const struct regmap_range ti_sn65dsi86_volatile_ranges[] = {
204 	{ .range_min = 0, .range_max = 0xFF },
205 };
206 
207 static const struct regmap_access_table ti_sn_bridge_volatile_table = {
208 	.yes_ranges = ti_sn65dsi86_volatile_ranges,
209 	.n_yes_ranges = ARRAY_SIZE(ti_sn65dsi86_volatile_ranges),
210 };
211 
212 static const struct regmap_config ti_sn65dsi86_regmap_config = {
213 	.reg_bits = 8,
214 	.val_bits = 8,
215 	.volatile_table = &ti_sn_bridge_volatile_table,
216 	.cache_type = REGCACHE_NONE,
217 	.max_register = 0xFF,
218 };
219 
220 static int __maybe_unused ti_sn65dsi86_read_u16(struct ti_sn65dsi86 *pdata,
221 						unsigned int reg, u16 *val)
222 {
223 	u8 buf[2];
224 	int ret;
225 
226 	ret = regmap_bulk_read(pdata->regmap, reg, buf, ARRAY_SIZE(buf));
227 	if (ret)
228 		return ret;
229 
230 	*val = buf[0] | (buf[1] << 8);
231 
232 	return 0;
233 }
234 
235 static void ti_sn65dsi86_write_u16(struct ti_sn65dsi86 *pdata,
236 				   unsigned int reg, u16 val)
237 {
238 	u8 buf[2] = { val & 0xff, val >> 8 };
239 
240 	regmap_bulk_write(pdata->regmap, reg, buf, ARRAY_SIZE(buf));
241 }
242 
243 static u32 ti_sn_bridge_get_dsi_freq(struct ti_sn65dsi86 *pdata)
244 {
245 	u32 bit_rate_khz, clk_freq_khz;
246 	struct drm_display_mode *mode =
247 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
248 
249 	bit_rate_khz = mode->clock *
250 			mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
251 	clk_freq_khz = bit_rate_khz / (pdata->dsi->lanes * 2);
252 
253 	return clk_freq_khz;
254 }
255 
256 /* clk frequencies supported by bridge in Hz in case derived from REFCLK pin */
257 static const u32 ti_sn_bridge_refclk_lut[] = {
258 	12000000,
259 	19200000,
260 	26000000,
261 	27000000,
262 	38400000,
263 };
264 
265 /* clk frequencies supported by bridge in Hz in case derived from DACP/N pin */
266 static const u32 ti_sn_bridge_dsiclk_lut[] = {
267 	468000000,
268 	384000000,
269 	416000000,
270 	486000000,
271 	460800000,
272 };
273 
274 static void ti_sn_bridge_set_refclk_freq(struct ti_sn65dsi86 *pdata)
275 {
276 	int i;
277 	u32 refclk_rate;
278 	const u32 *refclk_lut;
279 	size_t refclk_lut_size;
280 
281 	if (pdata->refclk) {
282 		refclk_rate = clk_get_rate(pdata->refclk);
283 		refclk_lut = ti_sn_bridge_refclk_lut;
284 		refclk_lut_size = ARRAY_SIZE(ti_sn_bridge_refclk_lut);
285 		clk_prepare_enable(pdata->refclk);
286 	} else {
287 		refclk_rate = ti_sn_bridge_get_dsi_freq(pdata) * 1000;
288 		refclk_lut = ti_sn_bridge_dsiclk_lut;
289 		refclk_lut_size = ARRAY_SIZE(ti_sn_bridge_dsiclk_lut);
290 	}
291 
292 	/* for i equals to refclk_lut_size means default frequency */
293 	for (i = 0; i < refclk_lut_size; i++)
294 		if (refclk_lut[i] == refclk_rate)
295 			break;
296 
297 	regmap_update_bits(pdata->regmap, SN_DPPLL_SRC_REG, REFCLK_FREQ_MASK,
298 			   REFCLK_FREQ(i));
299 
300 	/*
301 	 * The PWM refclk is based on the value written to SN_DPPLL_SRC_REG,
302 	 * regardless of its actual sourcing.
303 	 */
304 	pdata->pwm_refclk_freq = ti_sn_bridge_refclk_lut[i];
305 }
306 
307 static void ti_sn65dsi86_enable_comms(struct ti_sn65dsi86 *pdata)
308 {
309 	mutex_lock(&pdata->comms_mutex);
310 
311 	/* configure bridge ref_clk */
312 	ti_sn_bridge_set_refclk_freq(pdata);
313 
314 	/*
315 	 * HPD on this bridge chip is a bit useless.  This is an eDP bridge
316 	 * so the HPD is an internal signal that's only there to signal that
317 	 * the panel is done powering up.  ...but the bridge chip debounces
318 	 * this signal by between 100 ms and 400 ms (depending on process,
319 	 * voltage, and temperate--I measured it at about 200 ms).  One
320 	 * particular panel asserted HPD 84 ms after it was powered on meaning
321 	 * that we saw HPD 284 ms after power on.  ...but the same panel said
322 	 * that instead of looking at HPD you could just hardcode a delay of
323 	 * 200 ms.  We'll assume that the panel driver will have the hardcoded
324 	 * delay in its prepare and always disable HPD.
325 	 *
326 	 * If HPD somehow makes sense on some future panel we'll have to
327 	 * change this to be conditional on someone specifying that HPD should
328 	 * be used.
329 	 */
330 	regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE,
331 			   HPD_DISABLE);
332 
333 	pdata->comms_enabled = true;
334 
335 	mutex_unlock(&pdata->comms_mutex);
336 }
337 
338 static void ti_sn65dsi86_disable_comms(struct ti_sn65dsi86 *pdata)
339 {
340 	mutex_lock(&pdata->comms_mutex);
341 
342 	pdata->comms_enabled = false;
343 	clk_disable_unprepare(pdata->refclk);
344 
345 	mutex_unlock(&pdata->comms_mutex);
346 }
347 
348 static int __maybe_unused ti_sn65dsi86_resume(struct device *dev)
349 {
350 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(dev);
351 	int ret;
352 
353 	ret = regulator_bulk_enable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies);
354 	if (ret) {
355 		DRM_ERROR("failed to enable supplies %d\n", ret);
356 		return ret;
357 	}
358 
359 	/* td2: min 100 us after regulators before enabling the GPIO */
360 	usleep_range(100, 110);
361 
362 	gpiod_set_value(pdata->enable_gpio, 1);
363 
364 	/*
365 	 * If we have a reference clock we can enable communication w/ the
366 	 * panel (including the aux channel) w/out any need for an input clock
367 	 * so we can do it in resume which lets us read the EDID before
368 	 * pre_enable(). Without a reference clock we need the MIPI reference
369 	 * clock so reading early doesn't work.
370 	 */
371 	if (pdata->refclk)
372 		ti_sn65dsi86_enable_comms(pdata);
373 
374 	return ret;
375 }
376 
377 static int __maybe_unused ti_sn65dsi86_suspend(struct device *dev)
378 {
379 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(dev);
380 	int ret;
381 
382 	if (pdata->refclk)
383 		ti_sn65dsi86_disable_comms(pdata);
384 
385 	gpiod_set_value(pdata->enable_gpio, 0);
386 
387 	ret = regulator_bulk_disable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies);
388 	if (ret)
389 		DRM_ERROR("failed to disable supplies %d\n", ret);
390 
391 	return ret;
392 }
393 
394 static const struct dev_pm_ops ti_sn65dsi86_pm_ops = {
395 	SET_RUNTIME_PM_OPS(ti_sn65dsi86_suspend, ti_sn65dsi86_resume, NULL)
396 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
397 				pm_runtime_force_resume)
398 };
399 
400 static int status_show(struct seq_file *s, void *data)
401 {
402 	struct ti_sn65dsi86 *pdata = s->private;
403 	unsigned int reg, val;
404 
405 	seq_puts(s, "STATUS REGISTERS:\n");
406 
407 	pm_runtime_get_sync(pdata->dev);
408 
409 	/* IRQ Status Registers, see Table 31 in datasheet */
410 	for (reg = 0xf0; reg <= 0xf8; reg++) {
411 		regmap_read(pdata->regmap, reg, &val);
412 		seq_printf(s, "[0x%02x] = 0x%08x\n", reg, val);
413 	}
414 
415 	pm_runtime_put_autosuspend(pdata->dev);
416 
417 	return 0;
418 }
419 
420 DEFINE_SHOW_ATTRIBUTE(status);
421 
422 static void ti_sn65dsi86_debugfs_remove(void *data)
423 {
424 	debugfs_remove_recursive(data);
425 }
426 
427 static void ti_sn65dsi86_debugfs_init(struct ti_sn65dsi86 *pdata)
428 {
429 	struct device *dev = pdata->dev;
430 	struct dentry *debugfs;
431 	int ret;
432 
433 	debugfs = debugfs_create_dir(dev_name(dev), NULL);
434 
435 	/*
436 	 * We might get an error back if debugfs wasn't enabled in the kernel
437 	 * so let's just silently return upon failure.
438 	 */
439 	if (IS_ERR_OR_NULL(debugfs))
440 		return;
441 
442 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_debugfs_remove, debugfs);
443 	if (ret)
444 		return;
445 
446 	debugfs_create_file("status", 0600, debugfs, pdata, &status_fops);
447 }
448 
449 /* -----------------------------------------------------------------------------
450  * Auxiliary Devices (*not* AUX)
451  */
452 
453 static void ti_sn65dsi86_uninit_aux(void *data)
454 {
455 	auxiliary_device_uninit(data);
456 }
457 
458 static void ti_sn65dsi86_delete_aux(void *data)
459 {
460 	auxiliary_device_delete(data);
461 }
462 
463 /*
464  * AUX bus docs say that a non-NULL release is mandatory, but it makes no
465  * sense for the model used here where all of the aux devices are allocated
466  * in the single shared structure. We'll use this noop as a workaround.
467  */
468 static void ti_sn65dsi86_noop(struct device *dev) {}
469 
470 static int ti_sn65dsi86_add_aux_device(struct ti_sn65dsi86 *pdata,
471 				       struct auxiliary_device *aux,
472 				       const char *name)
473 {
474 	struct device *dev = pdata->dev;
475 	int ret;
476 
477 	aux->name = name;
478 	aux->dev.parent = dev;
479 	aux->dev.release = ti_sn65dsi86_noop;
480 	device_set_of_node_from_dev(&aux->dev, dev);
481 	ret = auxiliary_device_init(aux);
482 	if (ret)
483 		return ret;
484 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_uninit_aux, aux);
485 	if (ret)
486 		return ret;
487 
488 	ret = auxiliary_device_add(aux);
489 	if (ret)
490 		return ret;
491 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_delete_aux, aux);
492 
493 	return ret;
494 }
495 
496 /* -----------------------------------------------------------------------------
497  * AUX Adapter
498  */
499 
500 static struct ti_sn65dsi86 *aux_to_ti_sn65dsi86(struct drm_dp_aux *aux)
501 {
502 	return container_of(aux, struct ti_sn65dsi86, aux);
503 }
504 
505 static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux,
506 				  struct drm_dp_aux_msg *msg)
507 {
508 	struct ti_sn65dsi86 *pdata = aux_to_ti_sn65dsi86(aux);
509 	u32 request = msg->request & ~(DP_AUX_I2C_MOT | DP_AUX_I2C_WRITE_STATUS_UPDATE);
510 	u32 request_val = AUX_CMD_REQ(msg->request);
511 	u8 *buf = msg->buffer;
512 	unsigned int len = msg->size;
513 	unsigned int val;
514 	int ret;
515 	u8 addr_len[SN_AUX_LENGTH_REG + 1 - SN_AUX_ADDR_19_16_REG];
516 
517 	if (len > SN_AUX_MAX_PAYLOAD_BYTES)
518 		return -EINVAL;
519 
520 	pm_runtime_get_sync(pdata->dev);
521 	mutex_lock(&pdata->comms_mutex);
522 
523 	/*
524 	 * If someone tries to do a DDC over AUX transaction before pre_enable()
525 	 * on a device without a dedicated reference clock then we just can't
526 	 * do it. Fail right away. This prevents non-refclk users from reading
527 	 * the EDID before enabling the panel but such is life.
528 	 */
529 	if (!pdata->comms_enabled) {
530 		ret = -EIO;
531 		goto exit;
532 	}
533 
534 	switch (request) {
535 	case DP_AUX_NATIVE_WRITE:
536 	case DP_AUX_I2C_WRITE:
537 	case DP_AUX_NATIVE_READ:
538 	case DP_AUX_I2C_READ:
539 		regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val);
540 		/* Assume it's good */
541 		msg->reply = 0;
542 		break;
543 	default:
544 		ret = -EINVAL;
545 		goto exit;
546 	}
547 
548 	BUILD_BUG_ON(sizeof(addr_len) != sizeof(__be32));
549 	put_unaligned_be32((msg->address & SN_AUX_ADDR_MASK) << 8 | len,
550 			   addr_len);
551 	regmap_bulk_write(pdata->regmap, SN_AUX_ADDR_19_16_REG, addr_len,
552 			  ARRAY_SIZE(addr_len));
553 
554 	if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE)
555 		regmap_bulk_write(pdata->regmap, SN_AUX_WDATA_REG(0), buf, len);
556 
557 	/* Clear old status bits before start so we don't get confused */
558 	regmap_write(pdata->regmap, SN_AUX_CMD_STATUS_REG,
559 		     AUX_IRQ_STATUS_NAT_I2C_FAIL |
560 		     AUX_IRQ_STATUS_AUX_RPLY_TOUT |
561 		     AUX_IRQ_STATUS_AUX_SHORT);
562 
563 	regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val | AUX_CMD_SEND);
564 
565 	/* Zero delay loop because i2c transactions are slow already */
566 	ret = regmap_read_poll_timeout(pdata->regmap, SN_AUX_CMD_REG, val,
567 				       !(val & AUX_CMD_SEND), 0, 50 * 1000);
568 	if (ret)
569 		goto exit;
570 
571 	ret = regmap_read(pdata->regmap, SN_AUX_CMD_STATUS_REG, &val);
572 	if (ret)
573 		goto exit;
574 
575 	if (val & AUX_IRQ_STATUS_AUX_RPLY_TOUT) {
576 		/*
577 		 * The hardware tried the message seven times per the DP spec
578 		 * but it hit a timeout. We ignore defers here because they're
579 		 * handled in hardware.
580 		 */
581 		ret = -ETIMEDOUT;
582 		goto exit;
583 	}
584 
585 	if (val & AUX_IRQ_STATUS_AUX_SHORT) {
586 		ret = regmap_read(pdata->regmap, SN_AUX_LENGTH_REG, &len);
587 		if (ret)
588 			goto exit;
589 	} else if (val & AUX_IRQ_STATUS_NAT_I2C_FAIL) {
590 		switch (request) {
591 		case DP_AUX_I2C_WRITE:
592 		case DP_AUX_I2C_READ:
593 			msg->reply |= DP_AUX_I2C_REPLY_NACK;
594 			break;
595 		case DP_AUX_NATIVE_READ:
596 		case DP_AUX_NATIVE_WRITE:
597 			msg->reply |= DP_AUX_NATIVE_REPLY_NACK;
598 			break;
599 		}
600 		len = 0;
601 		goto exit;
602 	}
603 
604 	if (request != DP_AUX_NATIVE_WRITE && request != DP_AUX_I2C_WRITE && len != 0)
605 		ret = regmap_bulk_read(pdata->regmap, SN_AUX_RDATA_REG(0), buf, len);
606 
607 exit:
608 	mutex_unlock(&pdata->comms_mutex);
609 	pm_runtime_mark_last_busy(pdata->dev);
610 	pm_runtime_put_autosuspend(pdata->dev);
611 
612 	if (ret)
613 		return ret;
614 	return len;
615 }
616 
617 static int ti_sn_aux_probe(struct auxiliary_device *adev,
618 			   const struct auxiliary_device_id *id)
619 {
620 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
621 	int ret;
622 
623 	pdata->aux.name = "ti-sn65dsi86-aux";
624 	pdata->aux.dev = &adev->dev;
625 	pdata->aux.transfer = ti_sn_aux_transfer;
626 	drm_dp_aux_init(&pdata->aux);
627 
628 	ret = devm_of_dp_aux_populate_ep_devices(&pdata->aux);
629 	if (ret)
630 		return ret;
631 
632 	/*
633 	 * The eDP to MIPI bridge parts don't work until the AUX channel is
634 	 * setup so we don't add it in the main driver probe, we add it now.
635 	 */
636 	return ti_sn65dsi86_add_aux_device(pdata, &pdata->bridge_aux, "bridge");
637 }
638 
639 static const struct auxiliary_device_id ti_sn_aux_id_table[] = {
640 	{ .name = "ti_sn65dsi86.aux", },
641 	{},
642 };
643 
644 static struct auxiliary_driver ti_sn_aux_driver = {
645 	.name = "aux",
646 	.probe = ti_sn_aux_probe,
647 	.id_table = ti_sn_aux_id_table,
648 };
649 
650 /*------------------------------------------------------------------------------
651  * DRM Bridge
652  */
653 
654 static struct ti_sn65dsi86 *bridge_to_ti_sn65dsi86(struct drm_bridge *bridge)
655 {
656 	return container_of(bridge, struct ti_sn65dsi86, bridge);
657 }
658 
659 static int ti_sn_attach_host(struct ti_sn65dsi86 *pdata)
660 {
661 	int val;
662 	struct mipi_dsi_host *host;
663 	struct mipi_dsi_device *dsi;
664 	struct device *dev = pdata->dev;
665 	const struct mipi_dsi_device_info info = { .type = "ti_sn_bridge",
666 						   .channel = 0,
667 						   .node = NULL,
668 	};
669 
670 	host = of_find_mipi_dsi_host_by_node(pdata->host_node);
671 	if (!host)
672 		return -EPROBE_DEFER;
673 
674 	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
675 	if (IS_ERR(dsi))
676 		return PTR_ERR(dsi);
677 
678 	/* TODO: setting to 4 MIPI lanes always for now */
679 	dsi->lanes = 4;
680 	dsi->format = MIPI_DSI_FMT_RGB888;
681 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
682 
683 	/* check if continuous dsi clock is required or not */
684 	pm_runtime_get_sync(dev);
685 	regmap_read(pdata->regmap, SN_DPPLL_SRC_REG, &val);
686 	pm_runtime_put_autosuspend(dev);
687 	if (!(val & DPPLL_CLK_SRC_DSICLK))
688 		dsi->mode_flags |= MIPI_DSI_CLOCK_NON_CONTINUOUS;
689 
690 	pdata->dsi = dsi;
691 
692 	return devm_mipi_dsi_attach(dev, dsi);
693 }
694 
695 static int ti_sn_bridge_attach(struct drm_bridge *bridge,
696 			       enum drm_bridge_attach_flags flags)
697 {
698 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
699 	int ret;
700 
701 	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
702 		DRM_ERROR("Fix bridge driver to make connector optional!");
703 		return -EINVAL;
704 	}
705 
706 	pdata->aux.drm_dev = bridge->dev;
707 	ret = drm_dp_aux_register(&pdata->aux);
708 	if (ret < 0) {
709 		drm_err(bridge->dev, "Failed to register DP AUX channel: %d\n", ret);
710 		return ret;
711 	}
712 
713 	/* We never want the next bridge to *also* create a connector: */
714 	flags |= DRM_BRIDGE_ATTACH_NO_CONNECTOR;
715 
716 	/* Attach the next bridge */
717 	ret = drm_bridge_attach(bridge->encoder, pdata->next_bridge,
718 				&pdata->bridge, flags);
719 	if (ret < 0)
720 		goto err_initted_aux;
721 
722 	pdata->connector = drm_bridge_connector_init(pdata->bridge.dev,
723 						     pdata->bridge.encoder);
724 	if (IS_ERR(pdata->connector)) {
725 		ret = PTR_ERR(pdata->connector);
726 		goto err_initted_aux;
727 	}
728 
729 	drm_connector_attach_encoder(pdata->connector, pdata->bridge.encoder);
730 
731 	return 0;
732 
733 err_initted_aux:
734 	drm_dp_aux_unregister(&pdata->aux);
735 	return ret;
736 }
737 
738 static void ti_sn_bridge_detach(struct drm_bridge *bridge)
739 {
740 	drm_dp_aux_unregister(&bridge_to_ti_sn65dsi86(bridge)->aux);
741 }
742 
743 static enum drm_mode_status
744 ti_sn_bridge_mode_valid(struct drm_bridge *bridge,
745 			const struct drm_display_info *info,
746 			const struct drm_display_mode *mode)
747 {
748 	/* maximum supported resolution is 4K at 60 fps */
749 	if (mode->clock > 594000)
750 		return MODE_CLOCK_HIGH;
751 
752 	return MODE_OK;
753 }
754 
755 static void ti_sn_bridge_disable(struct drm_bridge *bridge)
756 {
757 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
758 
759 	/* disable video stream */
760 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE, 0);
761 }
762 
763 static void ti_sn_bridge_set_dsi_rate(struct ti_sn65dsi86 *pdata)
764 {
765 	unsigned int bit_rate_mhz, clk_freq_mhz;
766 	unsigned int val;
767 	struct drm_display_mode *mode =
768 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
769 
770 	/* set DSIA clk frequency */
771 	bit_rate_mhz = (mode->clock / 1000) *
772 			mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
773 	clk_freq_mhz = bit_rate_mhz / (pdata->dsi->lanes * 2);
774 
775 	/* for each increment in val, frequency increases by 5MHz */
776 	val = (MIN_DSI_CLK_FREQ_MHZ / 5) +
777 		(((clk_freq_mhz - MIN_DSI_CLK_FREQ_MHZ) / 5) & 0xFF);
778 	regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val);
779 }
780 
781 static unsigned int ti_sn_bridge_get_bpp(struct ti_sn65dsi86 *pdata)
782 {
783 	if (pdata->connector->display_info.bpc <= 6)
784 		return 18;
785 	else
786 		return 24;
787 }
788 
789 /*
790  * LUT index corresponds to register value and
791  * LUT values corresponds to dp data rate supported
792  * by the bridge in Mbps unit.
793  */
794 static const unsigned int ti_sn_bridge_dp_rate_lut[] = {
795 	0, 1620, 2160, 2430, 2700, 3240, 4320, 5400
796 };
797 
798 static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn65dsi86 *pdata)
799 {
800 	unsigned int bit_rate_khz, dp_rate_mhz;
801 	unsigned int i;
802 	struct drm_display_mode *mode =
803 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
804 
805 	/* Calculate minimum bit rate based on our pixel clock. */
806 	bit_rate_khz = mode->clock * ti_sn_bridge_get_bpp(pdata);
807 
808 	/* Calculate minimum DP data rate, taking 80% as per DP spec */
809 	dp_rate_mhz = DIV_ROUND_UP(bit_rate_khz * DP_CLK_FUDGE_NUM,
810 				   1000 * pdata->dp_lanes * DP_CLK_FUDGE_DEN);
811 
812 	for (i = 1; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++)
813 		if (ti_sn_bridge_dp_rate_lut[i] >= dp_rate_mhz)
814 			break;
815 
816 	return i;
817 }
818 
819 static unsigned int ti_sn_bridge_read_valid_rates(struct ti_sn65dsi86 *pdata)
820 {
821 	unsigned int valid_rates = 0;
822 	unsigned int rate_per_200khz;
823 	unsigned int rate_mhz;
824 	u8 dpcd_val;
825 	int ret;
826 	int i, j;
827 
828 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_EDP_DPCD_REV, &dpcd_val);
829 	if (ret != 1) {
830 		DRM_DEV_ERROR(pdata->dev,
831 			      "Can't read eDP rev (%d), assuming 1.1\n", ret);
832 		dpcd_val = DP_EDP_11;
833 	}
834 
835 	if (dpcd_val >= DP_EDP_14) {
836 		/* eDP 1.4 devices must provide a custom table */
837 		__le16 sink_rates[DP_MAX_SUPPORTED_RATES];
838 
839 		ret = drm_dp_dpcd_read(&pdata->aux, DP_SUPPORTED_LINK_RATES,
840 				       sink_rates, sizeof(sink_rates));
841 
842 		if (ret != sizeof(sink_rates)) {
843 			DRM_DEV_ERROR(pdata->dev,
844 				"Can't read supported rate table (%d)\n", ret);
845 
846 			/* By zeroing we'll fall back to DP_MAX_LINK_RATE. */
847 			memset(sink_rates, 0, sizeof(sink_rates));
848 		}
849 
850 		for (i = 0; i < ARRAY_SIZE(sink_rates); i++) {
851 			rate_per_200khz = le16_to_cpu(sink_rates[i]);
852 
853 			if (!rate_per_200khz)
854 				break;
855 
856 			rate_mhz = rate_per_200khz * 200 / 1000;
857 			for (j = 0;
858 			     j < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
859 			     j++) {
860 				if (ti_sn_bridge_dp_rate_lut[j] == rate_mhz)
861 					valid_rates |= BIT(j);
862 			}
863 		}
864 
865 		for (i = 0; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut); i++) {
866 			if (valid_rates & BIT(i))
867 				return valid_rates;
868 		}
869 		DRM_DEV_ERROR(pdata->dev,
870 			      "No matching eDP rates in table; falling back\n");
871 	}
872 
873 	/* On older versions best we can do is use DP_MAX_LINK_RATE */
874 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LINK_RATE, &dpcd_val);
875 	if (ret != 1) {
876 		DRM_DEV_ERROR(pdata->dev,
877 			      "Can't read max rate (%d); assuming 5.4 GHz\n",
878 			      ret);
879 		dpcd_val = DP_LINK_BW_5_4;
880 	}
881 
882 	switch (dpcd_val) {
883 	default:
884 		DRM_DEV_ERROR(pdata->dev,
885 			      "Unexpected max rate (%#x); assuming 5.4 GHz\n",
886 			      (int)dpcd_val);
887 		fallthrough;
888 	case DP_LINK_BW_5_4:
889 		valid_rates |= BIT(7);
890 		fallthrough;
891 	case DP_LINK_BW_2_7:
892 		valid_rates |= BIT(4);
893 		fallthrough;
894 	case DP_LINK_BW_1_62:
895 		valid_rates |= BIT(1);
896 		break;
897 	}
898 
899 	return valid_rates;
900 }
901 
902 static void ti_sn_bridge_set_video_timings(struct ti_sn65dsi86 *pdata)
903 {
904 	struct drm_display_mode *mode =
905 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
906 	u8 hsync_polarity = 0, vsync_polarity = 0;
907 
908 	if (mode->flags & DRM_MODE_FLAG_PHSYNC)
909 		hsync_polarity = CHA_HSYNC_POLARITY;
910 	if (mode->flags & DRM_MODE_FLAG_PVSYNC)
911 		vsync_polarity = CHA_VSYNC_POLARITY;
912 
913 	ti_sn65dsi86_write_u16(pdata, SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG,
914 			       mode->hdisplay);
915 	ti_sn65dsi86_write_u16(pdata, SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG,
916 			       mode->vdisplay);
917 	regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG,
918 		     (mode->hsync_end - mode->hsync_start) & 0xFF);
919 	regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_HIGH_REG,
920 		     (((mode->hsync_end - mode->hsync_start) >> 8) & 0x7F) |
921 		     hsync_polarity);
922 	regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG,
923 		     (mode->vsync_end - mode->vsync_start) & 0xFF);
924 	regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_HIGH_REG,
925 		     (((mode->vsync_end - mode->vsync_start) >> 8) & 0x7F) |
926 		     vsync_polarity);
927 
928 	regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_BACK_PORCH_REG,
929 		     (mode->htotal - mode->hsync_end) & 0xFF);
930 	regmap_write(pdata->regmap, SN_CHA_VERTICAL_BACK_PORCH_REG,
931 		     (mode->vtotal - mode->vsync_end) & 0xFF);
932 
933 	regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_FRONT_PORCH_REG,
934 		     (mode->hsync_start - mode->hdisplay) & 0xFF);
935 	regmap_write(pdata->regmap, SN_CHA_VERTICAL_FRONT_PORCH_REG,
936 		     (mode->vsync_start - mode->vdisplay) & 0xFF);
937 
938 	usleep_range(10000, 10500); /* 10ms delay recommended by spec */
939 }
940 
941 static unsigned int ti_sn_get_max_lanes(struct ti_sn65dsi86 *pdata)
942 {
943 	u8 data;
944 	int ret;
945 
946 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LANE_COUNT, &data);
947 	if (ret != 1) {
948 		DRM_DEV_ERROR(pdata->dev,
949 			      "Can't read lane count (%d); assuming 4\n", ret);
950 		return 4;
951 	}
952 
953 	return data & DP_LANE_COUNT_MASK;
954 }
955 
956 static int ti_sn_link_training(struct ti_sn65dsi86 *pdata, int dp_rate_idx,
957 			       const char **last_err_str)
958 {
959 	unsigned int val;
960 	int ret;
961 	int i;
962 
963 	/* set dp clk frequency value */
964 	regmap_update_bits(pdata->regmap, SN_DATARATE_CONFIG_REG,
965 			   DP_DATARATE_MASK, DP_DATARATE(dp_rate_idx));
966 
967 	/* enable DP PLL */
968 	regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
969 
970 	ret = regmap_read_poll_timeout(pdata->regmap, SN_DPPLL_SRC_REG, val,
971 				       val & DPPLL_SRC_DP_PLL_LOCK, 1000,
972 				       50 * 1000);
973 	if (ret) {
974 		*last_err_str = "DP_PLL_LOCK polling failed";
975 		goto exit;
976 	}
977 
978 	/*
979 	 * We'll try to link train several times.  As part of link training
980 	 * the bridge chip will write DP_SET_POWER_D0 to DP_SET_POWER.  If
981 	 * the panel isn't ready quite it might respond NAK here which means
982 	 * we need to try again.
983 	 */
984 	for (i = 0; i < SN_LINK_TRAINING_TRIES; i++) {
985 		/* Semi auto link training mode */
986 		regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A);
987 		ret = regmap_read_poll_timeout(pdata->regmap, SN_ML_TX_MODE_REG, val,
988 					       val == ML_TX_MAIN_LINK_OFF ||
989 					       val == ML_TX_NORMAL_MODE, 1000,
990 					       500 * 1000);
991 		if (ret) {
992 			*last_err_str = "Training complete polling failed";
993 		} else if (val == ML_TX_MAIN_LINK_OFF) {
994 			*last_err_str = "Link training failed, link is off";
995 			ret = -EIO;
996 			continue;
997 		}
998 
999 		break;
1000 	}
1001 
1002 	/* If we saw quite a few retries, add a note about it */
1003 	if (!ret && i > SN_LINK_TRAINING_TRIES / 2)
1004 		DRM_DEV_INFO(pdata->dev, "Link training needed %d retries\n", i);
1005 
1006 exit:
1007 	/* Disable the PLL if we failed */
1008 	if (ret)
1009 		regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
1010 
1011 	return ret;
1012 }
1013 
1014 static void ti_sn_bridge_enable(struct drm_bridge *bridge)
1015 {
1016 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1017 	const char *last_err_str = "No supported DP rate";
1018 	unsigned int valid_rates;
1019 	int dp_rate_idx;
1020 	unsigned int val;
1021 	int ret = -EINVAL;
1022 	int max_dp_lanes;
1023 
1024 	max_dp_lanes = ti_sn_get_max_lanes(pdata);
1025 	pdata->dp_lanes = min(pdata->dp_lanes, max_dp_lanes);
1026 
1027 	/* DSI_A lane config */
1028 	val = CHA_DSI_LANES(SN_MAX_DP_LANES - pdata->dsi->lanes);
1029 	regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG,
1030 			   CHA_DSI_LANES_MASK, val);
1031 
1032 	regmap_write(pdata->regmap, SN_LN_ASSIGN_REG, pdata->ln_assign);
1033 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, LN_POLRS_MASK,
1034 			   pdata->ln_polrs << LN_POLRS_OFFSET);
1035 
1036 	/* set dsi clk frequency value */
1037 	ti_sn_bridge_set_dsi_rate(pdata);
1038 
1039 	/*
1040 	 * The SN65DSI86 only supports ASSR Display Authentication method and
1041 	 * this method is enabled by default. An eDP panel must support this
1042 	 * authentication method. We need to enable this method in the eDP panel
1043 	 * at DisplayPort address 0x0010A prior to link training.
1044 	 */
1045 	drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET,
1046 			   DP_ALTERNATE_SCRAMBLER_RESET_ENABLE);
1047 
1048 	/* Set the DP output format (18 bpp or 24 bpp) */
1049 	val = (ti_sn_bridge_get_bpp(pdata) == 18) ? BPP_18_RGB : 0;
1050 	regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val);
1051 
1052 	/* DP lane config */
1053 	val = DP_NUM_LANES(min(pdata->dp_lanes, 3));
1054 	regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK,
1055 			   val);
1056 
1057 	valid_rates = ti_sn_bridge_read_valid_rates(pdata);
1058 
1059 	/* Train until we run out of rates */
1060 	for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata);
1061 	     dp_rate_idx < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
1062 	     dp_rate_idx++) {
1063 		if (!(valid_rates & BIT(dp_rate_idx)))
1064 			continue;
1065 
1066 		ret = ti_sn_link_training(pdata, dp_rate_idx, &last_err_str);
1067 		if (!ret)
1068 			break;
1069 	}
1070 	if (ret) {
1071 		DRM_DEV_ERROR(pdata->dev, "%s (%d)\n", last_err_str, ret);
1072 		return;
1073 	}
1074 
1075 	/* config video parameters */
1076 	ti_sn_bridge_set_video_timings(pdata);
1077 
1078 	/* enable video stream */
1079 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE,
1080 			   VSTREAM_ENABLE);
1081 }
1082 
1083 static void ti_sn_bridge_pre_enable(struct drm_bridge *bridge)
1084 {
1085 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1086 
1087 	pm_runtime_get_sync(pdata->dev);
1088 
1089 	if (!pdata->refclk)
1090 		ti_sn65dsi86_enable_comms(pdata);
1091 
1092 	/* td7: min 100 us after enable before DSI data */
1093 	usleep_range(100, 110);
1094 }
1095 
1096 static void ti_sn_bridge_post_disable(struct drm_bridge *bridge)
1097 {
1098 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1099 
1100 	/* semi auto link training mode OFF */
1101 	regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0);
1102 	/* Num lanes to 0 as per power sequencing in data sheet */
1103 	regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, 0);
1104 	/* disable DP PLL */
1105 	regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
1106 
1107 	if (!pdata->refclk)
1108 		ti_sn65dsi86_disable_comms(pdata);
1109 
1110 	pm_runtime_put_sync(pdata->dev);
1111 }
1112 
1113 static const struct drm_bridge_funcs ti_sn_bridge_funcs = {
1114 	.attach = ti_sn_bridge_attach,
1115 	.detach = ti_sn_bridge_detach,
1116 	.mode_valid = ti_sn_bridge_mode_valid,
1117 	.pre_enable = ti_sn_bridge_pre_enable,
1118 	.enable = ti_sn_bridge_enable,
1119 	.disable = ti_sn_bridge_disable,
1120 	.post_disable = ti_sn_bridge_post_disable,
1121 };
1122 
1123 static void ti_sn_bridge_parse_lanes(struct ti_sn65dsi86 *pdata,
1124 				     struct device_node *np)
1125 {
1126 	u32 lane_assignments[SN_MAX_DP_LANES] = { 0, 1, 2, 3 };
1127 	u32 lane_polarities[SN_MAX_DP_LANES] = { };
1128 	struct device_node *endpoint;
1129 	u8 ln_assign = 0;
1130 	u8 ln_polrs = 0;
1131 	int dp_lanes;
1132 	int i;
1133 
1134 	/*
1135 	 * Read config from the device tree about lane remapping and lane
1136 	 * polarities.  These are optional and we assume identity map and
1137 	 * normal polarity if nothing is specified.  It's OK to specify just
1138 	 * data-lanes but not lane-polarities but not vice versa.
1139 	 *
1140 	 * Error checking is light (we just make sure we don't crash or
1141 	 * buffer overrun) and we assume dts is well formed and specifying
1142 	 * mappings that the hardware supports.
1143 	 */
1144 	endpoint = of_graph_get_endpoint_by_regs(np, 1, -1);
1145 	dp_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
1146 	if (dp_lanes > 0 && dp_lanes <= SN_MAX_DP_LANES) {
1147 		of_property_read_u32_array(endpoint, "data-lanes",
1148 					   lane_assignments, dp_lanes);
1149 		of_property_read_u32_array(endpoint, "lane-polarities",
1150 					   lane_polarities, dp_lanes);
1151 	} else {
1152 		dp_lanes = SN_MAX_DP_LANES;
1153 	}
1154 	of_node_put(endpoint);
1155 
1156 	/*
1157 	 * Convert into register format.  Loop over all lanes even if
1158 	 * data-lanes had fewer elements so that we nicely initialize
1159 	 * the LN_ASSIGN register.
1160 	 */
1161 	for (i = SN_MAX_DP_LANES - 1; i >= 0; i--) {
1162 		ln_assign = ln_assign << LN_ASSIGN_WIDTH | lane_assignments[i];
1163 		ln_polrs = ln_polrs << 1 | lane_polarities[i];
1164 	}
1165 
1166 	/* Stash in our struct for when we power on */
1167 	pdata->dp_lanes = dp_lanes;
1168 	pdata->ln_assign = ln_assign;
1169 	pdata->ln_polrs = ln_polrs;
1170 }
1171 
1172 static int ti_sn_bridge_parse_dsi_host(struct ti_sn65dsi86 *pdata)
1173 {
1174 	struct device_node *np = pdata->dev->of_node;
1175 
1176 	pdata->host_node = of_graph_get_remote_node(np, 0, 0);
1177 
1178 	if (!pdata->host_node) {
1179 		DRM_ERROR("remote dsi host node not found\n");
1180 		return -ENODEV;
1181 	}
1182 
1183 	return 0;
1184 }
1185 
1186 static int ti_sn_bridge_probe(struct auxiliary_device *adev,
1187 			      const struct auxiliary_device_id *id)
1188 {
1189 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1190 	struct device_node *np = pdata->dev->of_node;
1191 	struct drm_panel *panel;
1192 	int ret;
1193 
1194 	ret = drm_of_find_panel_or_bridge(np, 1, 0, &panel, NULL);
1195 	if (ret)
1196 		return dev_err_probe(&adev->dev, ret,
1197 				     "could not find any panel node\n");
1198 
1199 	pdata->next_bridge = devm_drm_panel_bridge_add(pdata->dev, panel);
1200 	if (IS_ERR(pdata->next_bridge)) {
1201 		DRM_ERROR("failed to create panel bridge\n");
1202 		return PTR_ERR(pdata->next_bridge);
1203 	}
1204 
1205 	ti_sn_bridge_parse_lanes(pdata, np);
1206 
1207 	ret = ti_sn_bridge_parse_dsi_host(pdata);
1208 	if (ret)
1209 		return ret;
1210 
1211 	pdata->bridge.funcs = &ti_sn_bridge_funcs;
1212 	pdata->bridge.of_node = np;
1213 
1214 	drm_bridge_add(&pdata->bridge);
1215 
1216 	ret = ti_sn_attach_host(pdata);
1217 	if (ret) {
1218 		dev_err_probe(pdata->dev, ret, "failed to attach dsi host\n");
1219 		goto err_remove_bridge;
1220 	}
1221 
1222 	return 0;
1223 
1224 err_remove_bridge:
1225 	drm_bridge_remove(&pdata->bridge);
1226 	return ret;
1227 }
1228 
1229 static void ti_sn_bridge_remove(struct auxiliary_device *adev)
1230 {
1231 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1232 
1233 	if (!pdata)
1234 		return;
1235 
1236 	drm_bridge_remove(&pdata->bridge);
1237 
1238 	of_node_put(pdata->host_node);
1239 }
1240 
1241 static const struct auxiliary_device_id ti_sn_bridge_id_table[] = {
1242 	{ .name = "ti_sn65dsi86.bridge", },
1243 	{},
1244 };
1245 
1246 static struct auxiliary_driver ti_sn_bridge_driver = {
1247 	.name = "bridge",
1248 	.probe = ti_sn_bridge_probe,
1249 	.remove = ti_sn_bridge_remove,
1250 	.id_table = ti_sn_bridge_id_table,
1251 };
1252 
1253 /* -----------------------------------------------------------------------------
1254  * PWM Controller
1255  */
1256 #if defined(CONFIG_PWM)
1257 static int ti_sn_pwm_pin_request(struct ti_sn65dsi86 *pdata)
1258 {
1259 	return atomic_xchg(&pdata->pwm_pin_busy, 1) ? -EBUSY : 0;
1260 }
1261 
1262 static void ti_sn_pwm_pin_release(struct ti_sn65dsi86 *pdata)
1263 {
1264 	atomic_set(&pdata->pwm_pin_busy, 0);
1265 }
1266 
1267 static struct ti_sn65dsi86 *pwm_chip_to_ti_sn_bridge(struct pwm_chip *chip)
1268 {
1269 	return container_of(chip, struct ti_sn65dsi86, pchip);
1270 }
1271 
1272 static int ti_sn_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
1273 {
1274 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1275 
1276 	return ti_sn_pwm_pin_request(pdata);
1277 }
1278 
1279 static void ti_sn_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
1280 {
1281 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1282 
1283 	ti_sn_pwm_pin_release(pdata);
1284 }
1285 
1286 /*
1287  * Limitations:
1288  * - The PWM signal is not driven when the chip is powered down, or in its
1289  *   reset state and the driver does not implement the "suspend state"
1290  *   described in the documentation. In order to save power, state->enabled is
1291  *   interpreted as denoting if the signal is expected to be valid, and is used
1292  *   to determine if the chip needs to be kept powered.
1293  * - Changing both period and duty_cycle is not done atomically, neither is the
1294  *   multi-byte register updates, so the output might briefly be undefined
1295  *   during update.
1296  */
1297 static int ti_sn_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
1298 			   const struct pwm_state *state)
1299 {
1300 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1301 	unsigned int pwm_en_inv;
1302 	unsigned int backlight;
1303 	unsigned int pre_div;
1304 	unsigned int scale;
1305 	u64 period_max;
1306 	u64 period;
1307 	int ret;
1308 
1309 	if (!pdata->pwm_enabled) {
1310 		ret = pm_runtime_get_sync(pdata->dev);
1311 		if (ret < 0) {
1312 			pm_runtime_put_sync(pdata->dev);
1313 			return ret;
1314 		}
1315 	}
1316 
1317 	if (state->enabled) {
1318 		if (!pdata->pwm_enabled) {
1319 			/*
1320 			 * The chip might have been powered down while we
1321 			 * didn't hold a PM runtime reference, so mux in the
1322 			 * PWM function on the GPIO pin again.
1323 			 */
1324 			ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1325 						 SN_GPIO_MUX_MASK << (2 * SN_PWM_GPIO_IDX),
1326 						 SN_GPIO_MUX_SPECIAL << (2 * SN_PWM_GPIO_IDX));
1327 			if (ret) {
1328 				dev_err(pdata->dev, "failed to mux in PWM function\n");
1329 				goto out;
1330 			}
1331 		}
1332 
1333 		/*
1334 		 * Per the datasheet the PWM frequency is given by:
1335 		 *
1336 		 *                          REFCLK_FREQ
1337 		 *   PWM_FREQ = -----------------------------------
1338 		 *               PWM_PRE_DIV * BACKLIGHT_SCALE + 1
1339 		 *
1340 		 * However, after careful review the author is convinced that
1341 		 * the documentation has lost some parenthesis around
1342 		 * "BACKLIGHT_SCALE + 1".
1343 		 *
1344 		 * With the period T_pwm = 1/PWM_FREQ this can be written:
1345 		 *
1346 		 *   T_pwm * REFCLK_FREQ = PWM_PRE_DIV * (BACKLIGHT_SCALE + 1)
1347 		 *
1348 		 * In order to keep BACKLIGHT_SCALE within its 16 bits,
1349 		 * PWM_PRE_DIV must be:
1350 		 *
1351 		 *                     T_pwm * REFCLK_FREQ
1352 		 *   PWM_PRE_DIV >= -------------------------
1353 		 *                   BACKLIGHT_SCALE_MAX + 1
1354 		 *
1355 		 * To simplify the search and to favour higher resolution of
1356 		 * the duty cycle over accuracy of the period, the lowest
1357 		 * possible PWM_PRE_DIV is used. Finally the scale is
1358 		 * calculated as:
1359 		 *
1360 		 *                      T_pwm * REFCLK_FREQ
1361 		 *   BACKLIGHT_SCALE = ---------------------- - 1
1362 		 *                          PWM_PRE_DIV
1363 		 *
1364 		 * Here T_pwm is represented in seconds, so appropriate scaling
1365 		 * to nanoseconds is necessary.
1366 		 */
1367 
1368 		/* Minimum T_pwm is 1 / REFCLK_FREQ */
1369 		if (state->period <= NSEC_PER_SEC / pdata->pwm_refclk_freq) {
1370 			ret = -EINVAL;
1371 			goto out;
1372 		}
1373 
1374 		/*
1375 		 * Maximum T_pwm is 255 * (65535 + 1) / REFCLK_FREQ
1376 		 * Limit period to this to avoid overflows
1377 		 */
1378 		period_max = div_u64((u64)NSEC_PER_SEC * 255 * (65535 + 1),
1379 				     pdata->pwm_refclk_freq);
1380 		period = min(state->period, period_max);
1381 
1382 		pre_div = DIV64_U64_ROUND_UP(period * pdata->pwm_refclk_freq,
1383 					     (u64)NSEC_PER_SEC * (BACKLIGHT_SCALE_MAX + 1));
1384 		scale = div64_u64(period * pdata->pwm_refclk_freq, (u64)NSEC_PER_SEC * pre_div) - 1;
1385 
1386 		/*
1387 		 * The documentation has the duty ratio given as:
1388 		 *
1389 		 *     duty          BACKLIGHT
1390 		 *   ------- = ---------------------
1391 		 *    period    BACKLIGHT_SCALE + 1
1392 		 *
1393 		 * Solve for BACKLIGHT, substituting BACKLIGHT_SCALE according
1394 		 * to definition above and adjusting for nanosecond
1395 		 * representation of duty cycle gives us:
1396 		 */
1397 		backlight = div64_u64(state->duty_cycle * pdata->pwm_refclk_freq,
1398 				      (u64)NSEC_PER_SEC * pre_div);
1399 		if (backlight > scale)
1400 			backlight = scale;
1401 
1402 		ret = regmap_write(pdata->regmap, SN_PWM_PRE_DIV_REG, pre_div);
1403 		if (ret) {
1404 			dev_err(pdata->dev, "failed to update PWM_PRE_DIV\n");
1405 			goto out;
1406 		}
1407 
1408 		ti_sn65dsi86_write_u16(pdata, SN_BACKLIGHT_SCALE_REG, scale);
1409 		ti_sn65dsi86_write_u16(pdata, SN_BACKLIGHT_REG, backlight);
1410 	}
1411 
1412 	pwm_en_inv = FIELD_PREP(SN_PWM_EN_MASK, state->enabled) |
1413 		     FIELD_PREP(SN_PWM_INV_MASK, state->polarity == PWM_POLARITY_INVERSED);
1414 	ret = regmap_write(pdata->regmap, SN_PWM_EN_INV_REG, pwm_en_inv);
1415 	if (ret) {
1416 		dev_err(pdata->dev, "failed to update PWM_EN/PWM_INV\n");
1417 		goto out;
1418 	}
1419 
1420 	pdata->pwm_enabled = state->enabled;
1421 out:
1422 
1423 	if (!pdata->pwm_enabled)
1424 		pm_runtime_put_sync(pdata->dev);
1425 
1426 	return ret;
1427 }
1428 
1429 static void ti_sn_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
1430 				struct pwm_state *state)
1431 {
1432 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1433 	unsigned int pwm_en_inv;
1434 	unsigned int pre_div;
1435 	u16 backlight;
1436 	u16 scale;
1437 	int ret;
1438 
1439 	ret = regmap_read(pdata->regmap, SN_PWM_EN_INV_REG, &pwm_en_inv);
1440 	if (ret)
1441 		return;
1442 
1443 	ret = ti_sn65dsi86_read_u16(pdata, SN_BACKLIGHT_SCALE_REG, &scale);
1444 	if (ret)
1445 		return;
1446 
1447 	ret = ti_sn65dsi86_read_u16(pdata, SN_BACKLIGHT_REG, &backlight);
1448 	if (ret)
1449 		return;
1450 
1451 	ret = regmap_read(pdata->regmap, SN_PWM_PRE_DIV_REG, &pre_div);
1452 	if (ret)
1453 		return;
1454 
1455 	state->enabled = FIELD_GET(SN_PWM_EN_MASK, pwm_en_inv);
1456 	if (FIELD_GET(SN_PWM_INV_MASK, pwm_en_inv))
1457 		state->polarity = PWM_POLARITY_INVERSED;
1458 	else
1459 		state->polarity = PWM_POLARITY_NORMAL;
1460 
1461 	state->period = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * pre_div * (scale + 1),
1462 					 pdata->pwm_refclk_freq);
1463 	state->duty_cycle = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * pre_div * backlight,
1464 					     pdata->pwm_refclk_freq);
1465 
1466 	if (state->duty_cycle > state->period)
1467 		state->duty_cycle = state->period;
1468 }
1469 
1470 static const struct pwm_ops ti_sn_pwm_ops = {
1471 	.request = ti_sn_pwm_request,
1472 	.free = ti_sn_pwm_free,
1473 	.apply = ti_sn_pwm_apply,
1474 	.get_state = ti_sn_pwm_get_state,
1475 	.owner = THIS_MODULE,
1476 };
1477 
1478 static int ti_sn_pwm_probe(struct auxiliary_device *adev,
1479 			   const struct auxiliary_device_id *id)
1480 {
1481 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1482 
1483 	pdata->pchip.dev = pdata->dev;
1484 	pdata->pchip.ops = &ti_sn_pwm_ops;
1485 	pdata->pchip.npwm = 1;
1486 	pdata->pchip.of_xlate = of_pwm_single_xlate;
1487 	pdata->pchip.of_pwm_n_cells = 1;
1488 
1489 	return pwmchip_add(&pdata->pchip);
1490 }
1491 
1492 static void ti_sn_pwm_remove(struct auxiliary_device *adev)
1493 {
1494 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1495 
1496 	pwmchip_remove(&pdata->pchip);
1497 
1498 	if (pdata->pwm_enabled)
1499 		pm_runtime_put_sync(pdata->dev);
1500 }
1501 
1502 static const struct auxiliary_device_id ti_sn_pwm_id_table[] = {
1503 	{ .name = "ti_sn65dsi86.pwm", },
1504 	{},
1505 };
1506 
1507 static struct auxiliary_driver ti_sn_pwm_driver = {
1508 	.name = "pwm",
1509 	.probe = ti_sn_pwm_probe,
1510 	.remove = ti_sn_pwm_remove,
1511 	.id_table = ti_sn_pwm_id_table,
1512 };
1513 
1514 static int __init ti_sn_pwm_register(void)
1515 {
1516 	return auxiliary_driver_register(&ti_sn_pwm_driver);
1517 }
1518 
1519 static void ti_sn_pwm_unregister(void)
1520 {
1521 	auxiliary_driver_unregister(&ti_sn_pwm_driver);
1522 }
1523 
1524 #else
1525 static inline int ti_sn_pwm_pin_request(struct ti_sn65dsi86 *pdata) { return 0; }
1526 static inline void ti_sn_pwm_pin_release(struct ti_sn65dsi86 *pdata) {}
1527 
1528 static inline int ti_sn_pwm_register(void) { return 0; }
1529 static inline void ti_sn_pwm_unregister(void) {}
1530 #endif
1531 
1532 /* -----------------------------------------------------------------------------
1533  * GPIO Controller
1534  */
1535 #if defined(CONFIG_OF_GPIO)
1536 
1537 static int tn_sn_bridge_of_xlate(struct gpio_chip *chip,
1538 				 const struct of_phandle_args *gpiospec,
1539 				 u32 *flags)
1540 {
1541 	if (WARN_ON(gpiospec->args_count < chip->of_gpio_n_cells))
1542 		return -EINVAL;
1543 
1544 	if (gpiospec->args[0] > chip->ngpio || gpiospec->args[0] < 1)
1545 		return -EINVAL;
1546 
1547 	if (flags)
1548 		*flags = gpiospec->args[1];
1549 
1550 	return gpiospec->args[0] - SN_GPIO_PHYSICAL_OFFSET;
1551 }
1552 
1553 static int ti_sn_bridge_gpio_get_direction(struct gpio_chip *chip,
1554 					   unsigned int offset)
1555 {
1556 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1557 
1558 	/*
1559 	 * We already have to keep track of the direction because we use
1560 	 * that to figure out whether we've powered the device.  We can
1561 	 * just return that rather than (maybe) powering up the device
1562 	 * to ask its direction.
1563 	 */
1564 	return test_bit(offset, pdata->gchip_output) ?
1565 		GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
1566 }
1567 
1568 static int ti_sn_bridge_gpio_get(struct gpio_chip *chip, unsigned int offset)
1569 {
1570 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1571 	unsigned int val;
1572 	int ret;
1573 
1574 	/*
1575 	 * When the pin is an input we don't forcibly keep the bridge
1576 	 * powered--we just power it on to read the pin.  NOTE: part of
1577 	 * the reason this works is that the bridge defaults (when
1578 	 * powered back on) to all 4 GPIOs being configured as GPIO input.
1579 	 * Also note that if something else is keeping the chip powered the
1580 	 * pm_runtime functions are lightweight increments of a refcount.
1581 	 */
1582 	pm_runtime_get_sync(pdata->dev);
1583 	ret = regmap_read(pdata->regmap, SN_GPIO_IO_REG, &val);
1584 	pm_runtime_put_autosuspend(pdata->dev);
1585 
1586 	if (ret)
1587 		return ret;
1588 
1589 	return !!(val & BIT(SN_GPIO_INPUT_SHIFT + offset));
1590 }
1591 
1592 static void ti_sn_bridge_gpio_set(struct gpio_chip *chip, unsigned int offset,
1593 				  int val)
1594 {
1595 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1596 	int ret;
1597 
1598 	if (!test_bit(offset, pdata->gchip_output)) {
1599 		dev_err(pdata->dev, "Ignoring GPIO set while input\n");
1600 		return;
1601 	}
1602 
1603 	val &= 1;
1604 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_IO_REG,
1605 				 BIT(SN_GPIO_OUTPUT_SHIFT + offset),
1606 				 val << (SN_GPIO_OUTPUT_SHIFT + offset));
1607 	if (ret)
1608 		dev_warn(pdata->dev,
1609 			 "Failed to set bridge GPIO %u: %d\n", offset, ret);
1610 }
1611 
1612 static int ti_sn_bridge_gpio_direction_input(struct gpio_chip *chip,
1613 					     unsigned int offset)
1614 {
1615 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1616 	int shift = offset * 2;
1617 	int ret;
1618 
1619 	if (!test_and_clear_bit(offset, pdata->gchip_output))
1620 		return 0;
1621 
1622 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1623 				 SN_GPIO_MUX_MASK << shift,
1624 				 SN_GPIO_MUX_INPUT << shift);
1625 	if (ret) {
1626 		set_bit(offset, pdata->gchip_output);
1627 		return ret;
1628 	}
1629 
1630 	/*
1631 	 * NOTE: if nobody else is powering the device this may fully power
1632 	 * it off and when it comes back it will have lost all state, but
1633 	 * that's OK because the default is input and we're now an input.
1634 	 */
1635 	pm_runtime_put_autosuspend(pdata->dev);
1636 
1637 	return 0;
1638 }
1639 
1640 static int ti_sn_bridge_gpio_direction_output(struct gpio_chip *chip,
1641 					      unsigned int offset, int val)
1642 {
1643 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1644 	int shift = offset * 2;
1645 	int ret;
1646 
1647 	if (test_and_set_bit(offset, pdata->gchip_output))
1648 		return 0;
1649 
1650 	pm_runtime_get_sync(pdata->dev);
1651 
1652 	/* Set value first to avoid glitching */
1653 	ti_sn_bridge_gpio_set(chip, offset, val);
1654 
1655 	/* Set direction */
1656 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1657 				 SN_GPIO_MUX_MASK << shift,
1658 				 SN_GPIO_MUX_OUTPUT << shift);
1659 	if (ret) {
1660 		clear_bit(offset, pdata->gchip_output);
1661 		pm_runtime_put_autosuspend(pdata->dev);
1662 	}
1663 
1664 	return ret;
1665 }
1666 
1667 static int ti_sn_bridge_gpio_request(struct gpio_chip *chip, unsigned int offset)
1668 {
1669 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1670 
1671 	if (offset == SN_PWM_GPIO_IDX)
1672 		return ti_sn_pwm_pin_request(pdata);
1673 
1674 	return 0;
1675 }
1676 
1677 static void ti_sn_bridge_gpio_free(struct gpio_chip *chip, unsigned int offset)
1678 {
1679 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1680 
1681 	/* We won't keep pm_runtime if we're input, so switch there on free */
1682 	ti_sn_bridge_gpio_direction_input(chip, offset);
1683 
1684 	if (offset == SN_PWM_GPIO_IDX)
1685 		ti_sn_pwm_pin_release(pdata);
1686 }
1687 
1688 static const char * const ti_sn_bridge_gpio_names[SN_NUM_GPIOS] = {
1689 	"GPIO1", "GPIO2", "GPIO3", "GPIO4"
1690 };
1691 
1692 static int ti_sn_gpio_probe(struct auxiliary_device *adev,
1693 			    const struct auxiliary_device_id *id)
1694 {
1695 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1696 	int ret;
1697 
1698 	/* Only init if someone is going to use us as a GPIO controller */
1699 	if (!of_property_read_bool(pdata->dev->of_node, "gpio-controller"))
1700 		return 0;
1701 
1702 	pdata->gchip.label = dev_name(pdata->dev);
1703 	pdata->gchip.parent = pdata->dev;
1704 	pdata->gchip.owner = THIS_MODULE;
1705 	pdata->gchip.of_xlate = tn_sn_bridge_of_xlate;
1706 	pdata->gchip.of_gpio_n_cells = 2;
1707 	pdata->gchip.request = ti_sn_bridge_gpio_request;
1708 	pdata->gchip.free = ti_sn_bridge_gpio_free;
1709 	pdata->gchip.get_direction = ti_sn_bridge_gpio_get_direction;
1710 	pdata->gchip.direction_input = ti_sn_bridge_gpio_direction_input;
1711 	pdata->gchip.direction_output = ti_sn_bridge_gpio_direction_output;
1712 	pdata->gchip.get = ti_sn_bridge_gpio_get;
1713 	pdata->gchip.set = ti_sn_bridge_gpio_set;
1714 	pdata->gchip.can_sleep = true;
1715 	pdata->gchip.names = ti_sn_bridge_gpio_names;
1716 	pdata->gchip.ngpio = SN_NUM_GPIOS;
1717 	pdata->gchip.base = -1;
1718 	ret = devm_gpiochip_add_data(&adev->dev, &pdata->gchip, pdata);
1719 	if (ret)
1720 		dev_err(pdata->dev, "can't add gpio chip\n");
1721 
1722 	return ret;
1723 }
1724 
1725 static const struct auxiliary_device_id ti_sn_gpio_id_table[] = {
1726 	{ .name = "ti_sn65dsi86.gpio", },
1727 	{},
1728 };
1729 
1730 MODULE_DEVICE_TABLE(auxiliary, ti_sn_gpio_id_table);
1731 
1732 static struct auxiliary_driver ti_sn_gpio_driver = {
1733 	.name = "gpio",
1734 	.probe = ti_sn_gpio_probe,
1735 	.id_table = ti_sn_gpio_id_table,
1736 };
1737 
1738 static int __init ti_sn_gpio_register(void)
1739 {
1740 	return auxiliary_driver_register(&ti_sn_gpio_driver);
1741 }
1742 
1743 static void ti_sn_gpio_unregister(void)
1744 {
1745 	auxiliary_driver_unregister(&ti_sn_gpio_driver);
1746 }
1747 
1748 #else
1749 
1750 static inline int ti_sn_gpio_register(void) { return 0; }
1751 static inline void ti_sn_gpio_unregister(void) {}
1752 
1753 #endif
1754 
1755 /* -----------------------------------------------------------------------------
1756  * Probe & Remove
1757  */
1758 
1759 static void ti_sn65dsi86_runtime_disable(void *data)
1760 {
1761 	pm_runtime_disable(data);
1762 }
1763 
1764 static int ti_sn65dsi86_parse_regulators(struct ti_sn65dsi86 *pdata)
1765 {
1766 	unsigned int i;
1767 	const char * const ti_sn_bridge_supply_names[] = {
1768 		"vcca", "vcc", "vccio", "vpll",
1769 	};
1770 
1771 	for (i = 0; i < SN_REGULATOR_SUPPLY_NUM; i++)
1772 		pdata->supplies[i].supply = ti_sn_bridge_supply_names[i];
1773 
1774 	return devm_regulator_bulk_get(pdata->dev, SN_REGULATOR_SUPPLY_NUM,
1775 				       pdata->supplies);
1776 }
1777 
1778 static int ti_sn65dsi86_probe(struct i2c_client *client,
1779 			      const struct i2c_device_id *id)
1780 {
1781 	struct device *dev = &client->dev;
1782 	struct ti_sn65dsi86 *pdata;
1783 	int ret;
1784 
1785 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1786 		DRM_ERROR("device doesn't support I2C\n");
1787 		return -ENODEV;
1788 	}
1789 
1790 	pdata = devm_kzalloc(dev, sizeof(struct ti_sn65dsi86), GFP_KERNEL);
1791 	if (!pdata)
1792 		return -ENOMEM;
1793 	dev_set_drvdata(dev, pdata);
1794 	pdata->dev = dev;
1795 
1796 	mutex_init(&pdata->comms_mutex);
1797 
1798 	pdata->regmap = devm_regmap_init_i2c(client,
1799 					     &ti_sn65dsi86_regmap_config);
1800 	if (IS_ERR(pdata->regmap))
1801 		return dev_err_probe(dev, PTR_ERR(pdata->regmap),
1802 				     "regmap i2c init failed\n");
1803 
1804 	pdata->enable_gpio = devm_gpiod_get_optional(dev, "enable",
1805 						     GPIOD_OUT_LOW);
1806 	if (IS_ERR(pdata->enable_gpio))
1807 		return dev_err_probe(dev, PTR_ERR(pdata->enable_gpio),
1808 				     "failed to get enable gpio from DT\n");
1809 
1810 	ret = ti_sn65dsi86_parse_regulators(pdata);
1811 	if (ret)
1812 		return dev_err_probe(dev, ret, "failed to parse regulators\n");
1813 
1814 	pdata->refclk = devm_clk_get_optional(dev, "refclk");
1815 	if (IS_ERR(pdata->refclk))
1816 		return dev_err_probe(dev, PTR_ERR(pdata->refclk),
1817 				     "failed to get reference clock\n");
1818 
1819 	pm_runtime_enable(dev);
1820 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_runtime_disable, dev);
1821 	if (ret)
1822 		return ret;
1823 	pm_runtime_set_autosuspend_delay(pdata->dev, 500);
1824 	pm_runtime_use_autosuspend(pdata->dev);
1825 
1826 	ti_sn65dsi86_debugfs_init(pdata);
1827 
1828 	/*
1829 	 * Break ourselves up into a collection of aux devices. The only real
1830 	 * motiviation here is to solve the chicken-and-egg problem of probe
1831 	 * ordering. The bridge wants the panel to be there when it probes.
1832 	 * The panel wants its HPD GPIO (provided by sn65dsi86 on some boards)
1833 	 * when it probes. The panel and maybe backlight might want the DDC
1834 	 * bus or the pwm_chip. Having sub-devices allows the some sub devices
1835 	 * to finish probing even if others return -EPROBE_DEFER and gets us
1836 	 * around the problems.
1837 	 */
1838 
1839 	if (IS_ENABLED(CONFIG_OF_GPIO)) {
1840 		ret = ti_sn65dsi86_add_aux_device(pdata, &pdata->gpio_aux, "gpio");
1841 		if (ret)
1842 			return ret;
1843 	}
1844 
1845 	if (IS_ENABLED(CONFIG_PWM)) {
1846 		ret = ti_sn65dsi86_add_aux_device(pdata, &pdata->pwm_aux, "pwm");
1847 		if (ret)
1848 			return ret;
1849 	}
1850 
1851 	/*
1852 	 * NOTE: At the end of the AUX channel probe we'll add the aux device
1853 	 * for the bridge. This is because the bridge can't be used until the
1854 	 * AUX channel is there and this is a very simple solution to the
1855 	 * dependency problem.
1856 	 */
1857 	return ti_sn65dsi86_add_aux_device(pdata, &pdata->aux_aux, "aux");
1858 }
1859 
1860 static struct i2c_device_id ti_sn65dsi86_id[] = {
1861 	{ "ti,sn65dsi86", 0},
1862 	{},
1863 };
1864 MODULE_DEVICE_TABLE(i2c, ti_sn65dsi86_id);
1865 
1866 static const struct of_device_id ti_sn65dsi86_match_table[] = {
1867 	{.compatible = "ti,sn65dsi86"},
1868 	{},
1869 };
1870 MODULE_DEVICE_TABLE(of, ti_sn65dsi86_match_table);
1871 
1872 static struct i2c_driver ti_sn65dsi86_driver = {
1873 	.driver = {
1874 		.name = "ti_sn65dsi86",
1875 		.of_match_table = ti_sn65dsi86_match_table,
1876 		.pm = &ti_sn65dsi86_pm_ops,
1877 	},
1878 	.probe = ti_sn65dsi86_probe,
1879 	.id_table = ti_sn65dsi86_id,
1880 };
1881 
1882 static int __init ti_sn65dsi86_init(void)
1883 {
1884 	int ret;
1885 
1886 	ret = i2c_add_driver(&ti_sn65dsi86_driver);
1887 	if (ret)
1888 		return ret;
1889 
1890 	ret = ti_sn_gpio_register();
1891 	if (ret)
1892 		goto err_main_was_registered;
1893 
1894 	ret = ti_sn_pwm_register();
1895 	if (ret)
1896 		goto err_gpio_was_registered;
1897 
1898 	ret = auxiliary_driver_register(&ti_sn_aux_driver);
1899 	if (ret)
1900 		goto err_pwm_was_registered;
1901 
1902 	ret = auxiliary_driver_register(&ti_sn_bridge_driver);
1903 	if (ret)
1904 		goto err_aux_was_registered;
1905 
1906 	return 0;
1907 
1908 err_aux_was_registered:
1909 	auxiliary_driver_unregister(&ti_sn_aux_driver);
1910 err_pwm_was_registered:
1911 	ti_sn_pwm_unregister();
1912 err_gpio_was_registered:
1913 	ti_sn_gpio_unregister();
1914 err_main_was_registered:
1915 	i2c_del_driver(&ti_sn65dsi86_driver);
1916 
1917 	return ret;
1918 }
1919 module_init(ti_sn65dsi86_init);
1920 
1921 static void __exit ti_sn65dsi86_exit(void)
1922 {
1923 	auxiliary_driver_unregister(&ti_sn_bridge_driver);
1924 	auxiliary_driver_unregister(&ti_sn_aux_driver);
1925 	ti_sn_pwm_unregister();
1926 	ti_sn_gpio_unregister();
1927 	i2c_del_driver(&ti_sn65dsi86_driver);
1928 }
1929 module_exit(ti_sn65dsi86_exit);
1930 
1931 MODULE_AUTHOR("Sandeep Panda <spanda@codeaurora.org>");
1932 MODULE_DESCRIPTION("sn65dsi86 DSI to eDP bridge driver");
1933 MODULE_LICENSE("GPL v2");
1934