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/display/drm_dp_aux_bus.h>
27 #include <drm/display/drm_dp_helper.h>
28 #include <drm/drm_atomic.h>
29 #include <drm/drm_atomic_helper.h>
30 #include <drm/drm_bridge.h>
31 #include <drm/drm_bridge_connector.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_atomic_disable(struct drm_bridge *bridge,
756 					struct drm_bridge_state *old_bridge_state)
757 {
758 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
759 
760 	/* disable video stream */
761 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE, 0);
762 }
763 
764 static void ti_sn_bridge_set_dsi_rate(struct ti_sn65dsi86 *pdata)
765 {
766 	unsigned int bit_rate_mhz, clk_freq_mhz;
767 	unsigned int val;
768 	struct drm_display_mode *mode =
769 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
770 
771 	/* set DSIA clk frequency */
772 	bit_rate_mhz = (mode->clock / 1000) *
773 			mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
774 	clk_freq_mhz = bit_rate_mhz / (pdata->dsi->lanes * 2);
775 
776 	/* for each increment in val, frequency increases by 5MHz */
777 	val = (MIN_DSI_CLK_FREQ_MHZ / 5) +
778 		(((clk_freq_mhz - MIN_DSI_CLK_FREQ_MHZ) / 5) & 0xFF);
779 	regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val);
780 }
781 
782 static unsigned int ti_sn_bridge_get_bpp(struct ti_sn65dsi86 *pdata)
783 {
784 	if (pdata->connector->display_info.bpc <= 6)
785 		return 18;
786 	else
787 		return 24;
788 }
789 
790 /*
791  * LUT index corresponds to register value and
792  * LUT values corresponds to dp data rate supported
793  * by the bridge in Mbps unit.
794  */
795 static const unsigned int ti_sn_bridge_dp_rate_lut[] = {
796 	0, 1620, 2160, 2430, 2700, 3240, 4320, 5400
797 };
798 
799 static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn65dsi86 *pdata)
800 {
801 	unsigned int bit_rate_khz, dp_rate_mhz;
802 	unsigned int i;
803 	struct drm_display_mode *mode =
804 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
805 
806 	/* Calculate minimum bit rate based on our pixel clock. */
807 	bit_rate_khz = mode->clock * ti_sn_bridge_get_bpp(pdata);
808 
809 	/* Calculate minimum DP data rate, taking 80% as per DP spec */
810 	dp_rate_mhz = DIV_ROUND_UP(bit_rate_khz * DP_CLK_FUDGE_NUM,
811 				   1000 * pdata->dp_lanes * DP_CLK_FUDGE_DEN);
812 
813 	for (i = 1; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++)
814 		if (ti_sn_bridge_dp_rate_lut[i] >= dp_rate_mhz)
815 			break;
816 
817 	return i;
818 }
819 
820 static unsigned int ti_sn_bridge_read_valid_rates(struct ti_sn65dsi86 *pdata)
821 {
822 	unsigned int valid_rates = 0;
823 	unsigned int rate_per_200khz;
824 	unsigned int rate_mhz;
825 	u8 dpcd_val;
826 	int ret;
827 	int i, j;
828 
829 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_EDP_DPCD_REV, &dpcd_val);
830 	if (ret != 1) {
831 		DRM_DEV_ERROR(pdata->dev,
832 			      "Can't read eDP rev (%d), assuming 1.1\n", ret);
833 		dpcd_val = DP_EDP_11;
834 	}
835 
836 	if (dpcd_val >= DP_EDP_14) {
837 		/* eDP 1.4 devices must provide a custom table */
838 		__le16 sink_rates[DP_MAX_SUPPORTED_RATES];
839 
840 		ret = drm_dp_dpcd_read(&pdata->aux, DP_SUPPORTED_LINK_RATES,
841 				       sink_rates, sizeof(sink_rates));
842 
843 		if (ret != sizeof(sink_rates)) {
844 			DRM_DEV_ERROR(pdata->dev,
845 				"Can't read supported rate table (%d)\n", ret);
846 
847 			/* By zeroing we'll fall back to DP_MAX_LINK_RATE. */
848 			memset(sink_rates, 0, sizeof(sink_rates));
849 		}
850 
851 		for (i = 0; i < ARRAY_SIZE(sink_rates); i++) {
852 			rate_per_200khz = le16_to_cpu(sink_rates[i]);
853 
854 			if (!rate_per_200khz)
855 				break;
856 
857 			rate_mhz = rate_per_200khz * 200 / 1000;
858 			for (j = 0;
859 			     j < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
860 			     j++) {
861 				if (ti_sn_bridge_dp_rate_lut[j] == rate_mhz)
862 					valid_rates |= BIT(j);
863 			}
864 		}
865 
866 		for (i = 0; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut); i++) {
867 			if (valid_rates & BIT(i))
868 				return valid_rates;
869 		}
870 		DRM_DEV_ERROR(pdata->dev,
871 			      "No matching eDP rates in table; falling back\n");
872 	}
873 
874 	/* On older versions best we can do is use DP_MAX_LINK_RATE */
875 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LINK_RATE, &dpcd_val);
876 	if (ret != 1) {
877 		DRM_DEV_ERROR(pdata->dev,
878 			      "Can't read max rate (%d); assuming 5.4 GHz\n",
879 			      ret);
880 		dpcd_val = DP_LINK_BW_5_4;
881 	}
882 
883 	switch (dpcd_val) {
884 	default:
885 		DRM_DEV_ERROR(pdata->dev,
886 			      "Unexpected max rate (%#x); assuming 5.4 GHz\n",
887 			      (int)dpcd_val);
888 		fallthrough;
889 	case DP_LINK_BW_5_4:
890 		valid_rates |= BIT(7);
891 		fallthrough;
892 	case DP_LINK_BW_2_7:
893 		valid_rates |= BIT(4);
894 		fallthrough;
895 	case DP_LINK_BW_1_62:
896 		valid_rates |= BIT(1);
897 		break;
898 	}
899 
900 	return valid_rates;
901 }
902 
903 static void ti_sn_bridge_set_video_timings(struct ti_sn65dsi86 *pdata)
904 {
905 	struct drm_display_mode *mode =
906 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
907 	u8 hsync_polarity = 0, vsync_polarity = 0;
908 
909 	if (mode->flags & DRM_MODE_FLAG_PHSYNC)
910 		hsync_polarity = CHA_HSYNC_POLARITY;
911 	if (mode->flags & DRM_MODE_FLAG_PVSYNC)
912 		vsync_polarity = CHA_VSYNC_POLARITY;
913 
914 	ti_sn65dsi86_write_u16(pdata, SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG,
915 			       mode->hdisplay);
916 	ti_sn65dsi86_write_u16(pdata, SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG,
917 			       mode->vdisplay);
918 	regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG,
919 		     (mode->hsync_end - mode->hsync_start) & 0xFF);
920 	regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_HIGH_REG,
921 		     (((mode->hsync_end - mode->hsync_start) >> 8) & 0x7F) |
922 		     hsync_polarity);
923 	regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG,
924 		     (mode->vsync_end - mode->vsync_start) & 0xFF);
925 	regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_HIGH_REG,
926 		     (((mode->vsync_end - mode->vsync_start) >> 8) & 0x7F) |
927 		     vsync_polarity);
928 
929 	regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_BACK_PORCH_REG,
930 		     (mode->htotal - mode->hsync_end) & 0xFF);
931 	regmap_write(pdata->regmap, SN_CHA_VERTICAL_BACK_PORCH_REG,
932 		     (mode->vtotal - mode->vsync_end) & 0xFF);
933 
934 	regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_FRONT_PORCH_REG,
935 		     (mode->hsync_start - mode->hdisplay) & 0xFF);
936 	regmap_write(pdata->regmap, SN_CHA_VERTICAL_FRONT_PORCH_REG,
937 		     (mode->vsync_start - mode->vdisplay) & 0xFF);
938 
939 	usleep_range(10000, 10500); /* 10ms delay recommended by spec */
940 }
941 
942 static unsigned int ti_sn_get_max_lanes(struct ti_sn65dsi86 *pdata)
943 {
944 	u8 data;
945 	int ret;
946 
947 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LANE_COUNT, &data);
948 	if (ret != 1) {
949 		DRM_DEV_ERROR(pdata->dev,
950 			      "Can't read lane count (%d); assuming 4\n", ret);
951 		return 4;
952 	}
953 
954 	return data & DP_LANE_COUNT_MASK;
955 }
956 
957 static int ti_sn_link_training(struct ti_sn65dsi86 *pdata, int dp_rate_idx,
958 			       const char **last_err_str)
959 {
960 	unsigned int val;
961 	int ret;
962 	int i;
963 
964 	/* set dp clk frequency value */
965 	regmap_update_bits(pdata->regmap, SN_DATARATE_CONFIG_REG,
966 			   DP_DATARATE_MASK, DP_DATARATE(dp_rate_idx));
967 
968 	/* enable DP PLL */
969 	regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
970 
971 	ret = regmap_read_poll_timeout(pdata->regmap, SN_DPPLL_SRC_REG, val,
972 				       val & DPPLL_SRC_DP_PLL_LOCK, 1000,
973 				       50 * 1000);
974 	if (ret) {
975 		*last_err_str = "DP_PLL_LOCK polling failed";
976 		goto exit;
977 	}
978 
979 	/*
980 	 * We'll try to link train several times.  As part of link training
981 	 * the bridge chip will write DP_SET_POWER_D0 to DP_SET_POWER.  If
982 	 * the panel isn't ready quite it might respond NAK here which means
983 	 * we need to try again.
984 	 */
985 	for (i = 0; i < SN_LINK_TRAINING_TRIES; i++) {
986 		/* Semi auto link training mode */
987 		regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A);
988 		ret = regmap_read_poll_timeout(pdata->regmap, SN_ML_TX_MODE_REG, val,
989 					       val == ML_TX_MAIN_LINK_OFF ||
990 					       val == ML_TX_NORMAL_MODE, 1000,
991 					       500 * 1000);
992 		if (ret) {
993 			*last_err_str = "Training complete polling failed";
994 		} else if (val == ML_TX_MAIN_LINK_OFF) {
995 			*last_err_str = "Link training failed, link is off";
996 			ret = -EIO;
997 			continue;
998 		}
999 
1000 		break;
1001 	}
1002 
1003 	/* If we saw quite a few retries, add a note about it */
1004 	if (!ret && i > SN_LINK_TRAINING_TRIES / 2)
1005 		DRM_DEV_INFO(pdata->dev, "Link training needed %d retries\n", i);
1006 
1007 exit:
1008 	/* Disable the PLL if we failed */
1009 	if (ret)
1010 		regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
1011 
1012 	return ret;
1013 }
1014 
1015 static void ti_sn_bridge_atomic_enable(struct drm_bridge *bridge,
1016 				       struct drm_bridge_state *old_bridge_state)
1017 {
1018 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1019 	const char *last_err_str = "No supported DP rate";
1020 	unsigned int valid_rates;
1021 	int dp_rate_idx;
1022 	unsigned int val;
1023 	int ret = -EINVAL;
1024 	int max_dp_lanes;
1025 
1026 	max_dp_lanes = ti_sn_get_max_lanes(pdata);
1027 	pdata->dp_lanes = min(pdata->dp_lanes, max_dp_lanes);
1028 
1029 	/* DSI_A lane config */
1030 	val = CHA_DSI_LANES(SN_MAX_DP_LANES - pdata->dsi->lanes);
1031 	regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG,
1032 			   CHA_DSI_LANES_MASK, val);
1033 
1034 	regmap_write(pdata->regmap, SN_LN_ASSIGN_REG, pdata->ln_assign);
1035 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, LN_POLRS_MASK,
1036 			   pdata->ln_polrs << LN_POLRS_OFFSET);
1037 
1038 	/* set dsi clk frequency value */
1039 	ti_sn_bridge_set_dsi_rate(pdata);
1040 
1041 	/*
1042 	 * The SN65DSI86 only supports ASSR Display Authentication method and
1043 	 * this method is enabled by default. An eDP panel must support this
1044 	 * authentication method. We need to enable this method in the eDP panel
1045 	 * at DisplayPort address 0x0010A prior to link training.
1046 	 */
1047 	drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET,
1048 			   DP_ALTERNATE_SCRAMBLER_RESET_ENABLE);
1049 
1050 	/* Set the DP output format (18 bpp or 24 bpp) */
1051 	val = (ti_sn_bridge_get_bpp(pdata) == 18) ? BPP_18_RGB : 0;
1052 	regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val);
1053 
1054 	/* DP lane config */
1055 	val = DP_NUM_LANES(min(pdata->dp_lanes, 3));
1056 	regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK,
1057 			   val);
1058 
1059 	valid_rates = ti_sn_bridge_read_valid_rates(pdata);
1060 
1061 	/* Train until we run out of rates */
1062 	for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata);
1063 	     dp_rate_idx < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
1064 	     dp_rate_idx++) {
1065 		if (!(valid_rates & BIT(dp_rate_idx)))
1066 			continue;
1067 
1068 		ret = ti_sn_link_training(pdata, dp_rate_idx, &last_err_str);
1069 		if (!ret)
1070 			break;
1071 	}
1072 	if (ret) {
1073 		DRM_DEV_ERROR(pdata->dev, "%s (%d)\n", last_err_str, ret);
1074 		return;
1075 	}
1076 
1077 	/* config video parameters */
1078 	ti_sn_bridge_set_video_timings(pdata);
1079 
1080 	/* enable video stream */
1081 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE,
1082 			   VSTREAM_ENABLE);
1083 }
1084 
1085 static void ti_sn_bridge_atomic_pre_enable(struct drm_bridge *bridge,
1086 					   struct drm_bridge_state *old_bridge_state)
1087 {
1088 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1089 
1090 	pm_runtime_get_sync(pdata->dev);
1091 
1092 	if (!pdata->refclk)
1093 		ti_sn65dsi86_enable_comms(pdata);
1094 
1095 	/* td7: min 100 us after enable before DSI data */
1096 	usleep_range(100, 110);
1097 }
1098 
1099 static void ti_sn_bridge_atomic_post_disable(struct drm_bridge *bridge,
1100 					     struct drm_bridge_state *old_bridge_state)
1101 {
1102 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1103 
1104 	/* semi auto link training mode OFF */
1105 	regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0);
1106 	/* Num lanes to 0 as per power sequencing in data sheet */
1107 	regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, 0);
1108 	/* disable DP PLL */
1109 	regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
1110 
1111 	if (!pdata->refclk)
1112 		ti_sn65dsi86_disable_comms(pdata);
1113 
1114 	pm_runtime_put_sync(pdata->dev);
1115 }
1116 
1117 static const struct drm_bridge_funcs ti_sn_bridge_funcs = {
1118 	.attach = ti_sn_bridge_attach,
1119 	.detach = ti_sn_bridge_detach,
1120 	.mode_valid = ti_sn_bridge_mode_valid,
1121 	.atomic_pre_enable = ti_sn_bridge_atomic_pre_enable,
1122 	.atomic_enable = ti_sn_bridge_atomic_enable,
1123 	.atomic_disable = ti_sn_bridge_atomic_disable,
1124 	.atomic_post_disable = ti_sn_bridge_atomic_post_disable,
1125 	.atomic_reset = drm_atomic_helper_bridge_reset,
1126 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
1127 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
1128 };
1129 
1130 static void ti_sn_bridge_parse_lanes(struct ti_sn65dsi86 *pdata,
1131 				     struct device_node *np)
1132 {
1133 	u32 lane_assignments[SN_MAX_DP_LANES] = { 0, 1, 2, 3 };
1134 	u32 lane_polarities[SN_MAX_DP_LANES] = { };
1135 	struct device_node *endpoint;
1136 	u8 ln_assign = 0;
1137 	u8 ln_polrs = 0;
1138 	int dp_lanes;
1139 	int i;
1140 
1141 	/*
1142 	 * Read config from the device tree about lane remapping and lane
1143 	 * polarities.  These are optional and we assume identity map and
1144 	 * normal polarity if nothing is specified.  It's OK to specify just
1145 	 * data-lanes but not lane-polarities but not vice versa.
1146 	 *
1147 	 * Error checking is light (we just make sure we don't crash or
1148 	 * buffer overrun) and we assume dts is well formed and specifying
1149 	 * mappings that the hardware supports.
1150 	 */
1151 	endpoint = of_graph_get_endpoint_by_regs(np, 1, -1);
1152 	dp_lanes = drm_of_get_data_lanes_count(endpoint, 1, SN_MAX_DP_LANES);
1153 	if (dp_lanes > 0) {
1154 		of_property_read_u32_array(endpoint, "data-lanes",
1155 					   lane_assignments, dp_lanes);
1156 		of_property_read_u32_array(endpoint, "lane-polarities",
1157 					   lane_polarities, dp_lanes);
1158 	} else {
1159 		dp_lanes = SN_MAX_DP_LANES;
1160 	}
1161 	of_node_put(endpoint);
1162 
1163 	/*
1164 	 * Convert into register format.  Loop over all lanes even if
1165 	 * data-lanes had fewer elements so that we nicely initialize
1166 	 * the LN_ASSIGN register.
1167 	 */
1168 	for (i = SN_MAX_DP_LANES - 1; i >= 0; i--) {
1169 		ln_assign = ln_assign << LN_ASSIGN_WIDTH | lane_assignments[i];
1170 		ln_polrs = ln_polrs << 1 | lane_polarities[i];
1171 	}
1172 
1173 	/* Stash in our struct for when we power on */
1174 	pdata->dp_lanes = dp_lanes;
1175 	pdata->ln_assign = ln_assign;
1176 	pdata->ln_polrs = ln_polrs;
1177 }
1178 
1179 static int ti_sn_bridge_parse_dsi_host(struct ti_sn65dsi86 *pdata)
1180 {
1181 	struct device_node *np = pdata->dev->of_node;
1182 
1183 	pdata->host_node = of_graph_get_remote_node(np, 0, 0);
1184 
1185 	if (!pdata->host_node) {
1186 		DRM_ERROR("remote dsi host node not found\n");
1187 		return -ENODEV;
1188 	}
1189 
1190 	return 0;
1191 }
1192 
1193 static int ti_sn_bridge_probe(struct auxiliary_device *adev,
1194 			      const struct auxiliary_device_id *id)
1195 {
1196 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1197 	struct device_node *np = pdata->dev->of_node;
1198 	int ret;
1199 
1200 	pdata->next_bridge = devm_drm_of_get_bridge(pdata->dev, np, 1, 0);
1201 	if (IS_ERR(pdata->next_bridge)) {
1202 		DRM_ERROR("failed to create panel bridge\n");
1203 		return PTR_ERR(pdata->next_bridge);
1204 	}
1205 
1206 	ti_sn_bridge_parse_lanes(pdata, np);
1207 
1208 	ret = ti_sn_bridge_parse_dsi_host(pdata);
1209 	if (ret)
1210 		return ret;
1211 
1212 	pdata->bridge.funcs = &ti_sn_bridge_funcs;
1213 	pdata->bridge.of_node = np;
1214 
1215 	drm_bridge_add(&pdata->bridge);
1216 
1217 	ret = ti_sn_attach_host(pdata);
1218 	if (ret) {
1219 		dev_err_probe(pdata->dev, ret, "failed to attach dsi host\n");
1220 		goto err_remove_bridge;
1221 	}
1222 
1223 	return 0;
1224 
1225 err_remove_bridge:
1226 	drm_bridge_remove(&pdata->bridge);
1227 	return ret;
1228 }
1229 
1230 static void ti_sn_bridge_remove(struct auxiliary_device *adev)
1231 {
1232 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1233 
1234 	if (!pdata)
1235 		return;
1236 
1237 	drm_bridge_remove(&pdata->bridge);
1238 
1239 	of_node_put(pdata->host_node);
1240 }
1241 
1242 static const struct auxiliary_device_id ti_sn_bridge_id_table[] = {
1243 	{ .name = "ti_sn65dsi86.bridge", },
1244 	{},
1245 };
1246 
1247 static struct auxiliary_driver ti_sn_bridge_driver = {
1248 	.name = "bridge",
1249 	.probe = ti_sn_bridge_probe,
1250 	.remove = ti_sn_bridge_remove,
1251 	.id_table = ti_sn_bridge_id_table,
1252 };
1253 
1254 /* -----------------------------------------------------------------------------
1255  * PWM Controller
1256  */
1257 #if defined(CONFIG_PWM)
1258 static int ti_sn_pwm_pin_request(struct ti_sn65dsi86 *pdata)
1259 {
1260 	return atomic_xchg(&pdata->pwm_pin_busy, 1) ? -EBUSY : 0;
1261 }
1262 
1263 static void ti_sn_pwm_pin_release(struct ti_sn65dsi86 *pdata)
1264 {
1265 	atomic_set(&pdata->pwm_pin_busy, 0);
1266 }
1267 
1268 static struct ti_sn65dsi86 *pwm_chip_to_ti_sn_bridge(struct pwm_chip *chip)
1269 {
1270 	return container_of(chip, struct ti_sn65dsi86, pchip);
1271 }
1272 
1273 static int ti_sn_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
1274 {
1275 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1276 
1277 	return ti_sn_pwm_pin_request(pdata);
1278 }
1279 
1280 static void ti_sn_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
1281 {
1282 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1283 
1284 	ti_sn_pwm_pin_release(pdata);
1285 }
1286 
1287 /*
1288  * Limitations:
1289  * - The PWM signal is not driven when the chip is powered down, or in its
1290  *   reset state and the driver does not implement the "suspend state"
1291  *   described in the documentation. In order to save power, state->enabled is
1292  *   interpreted as denoting if the signal is expected to be valid, and is used
1293  *   to determine if the chip needs to be kept powered.
1294  * - Changing both period and duty_cycle is not done atomically, neither is the
1295  *   multi-byte register updates, so the output might briefly be undefined
1296  *   during update.
1297  */
1298 static int ti_sn_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
1299 			   const struct pwm_state *state)
1300 {
1301 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1302 	unsigned int pwm_en_inv;
1303 	unsigned int backlight;
1304 	unsigned int pre_div;
1305 	unsigned int scale;
1306 	u64 period_max;
1307 	u64 period;
1308 	int ret;
1309 
1310 	if (!pdata->pwm_enabled) {
1311 		ret = pm_runtime_get_sync(pdata->dev);
1312 		if (ret < 0) {
1313 			pm_runtime_put_sync(pdata->dev);
1314 			return ret;
1315 		}
1316 	}
1317 
1318 	if (state->enabled) {
1319 		if (!pdata->pwm_enabled) {
1320 			/*
1321 			 * The chip might have been powered down while we
1322 			 * didn't hold a PM runtime reference, so mux in the
1323 			 * PWM function on the GPIO pin again.
1324 			 */
1325 			ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1326 						 SN_GPIO_MUX_MASK << (2 * SN_PWM_GPIO_IDX),
1327 						 SN_GPIO_MUX_SPECIAL << (2 * SN_PWM_GPIO_IDX));
1328 			if (ret) {
1329 				dev_err(pdata->dev, "failed to mux in PWM function\n");
1330 				goto out;
1331 			}
1332 		}
1333 
1334 		/*
1335 		 * Per the datasheet the PWM frequency is given by:
1336 		 *
1337 		 *                          REFCLK_FREQ
1338 		 *   PWM_FREQ = -----------------------------------
1339 		 *               PWM_PRE_DIV * BACKLIGHT_SCALE + 1
1340 		 *
1341 		 * However, after careful review the author is convinced that
1342 		 * the documentation has lost some parenthesis around
1343 		 * "BACKLIGHT_SCALE + 1".
1344 		 *
1345 		 * With the period T_pwm = 1/PWM_FREQ this can be written:
1346 		 *
1347 		 *   T_pwm * REFCLK_FREQ = PWM_PRE_DIV * (BACKLIGHT_SCALE + 1)
1348 		 *
1349 		 * In order to keep BACKLIGHT_SCALE within its 16 bits,
1350 		 * PWM_PRE_DIV must be:
1351 		 *
1352 		 *                     T_pwm * REFCLK_FREQ
1353 		 *   PWM_PRE_DIV >= -------------------------
1354 		 *                   BACKLIGHT_SCALE_MAX + 1
1355 		 *
1356 		 * To simplify the search and to favour higher resolution of
1357 		 * the duty cycle over accuracy of the period, the lowest
1358 		 * possible PWM_PRE_DIV is used. Finally the scale is
1359 		 * calculated as:
1360 		 *
1361 		 *                      T_pwm * REFCLK_FREQ
1362 		 *   BACKLIGHT_SCALE = ---------------------- - 1
1363 		 *                          PWM_PRE_DIV
1364 		 *
1365 		 * Here T_pwm is represented in seconds, so appropriate scaling
1366 		 * to nanoseconds is necessary.
1367 		 */
1368 
1369 		/* Minimum T_pwm is 1 / REFCLK_FREQ */
1370 		if (state->period <= NSEC_PER_SEC / pdata->pwm_refclk_freq) {
1371 			ret = -EINVAL;
1372 			goto out;
1373 		}
1374 
1375 		/*
1376 		 * Maximum T_pwm is 255 * (65535 + 1) / REFCLK_FREQ
1377 		 * Limit period to this to avoid overflows
1378 		 */
1379 		period_max = div_u64((u64)NSEC_PER_SEC * 255 * (65535 + 1),
1380 				     pdata->pwm_refclk_freq);
1381 		period = min(state->period, period_max);
1382 
1383 		pre_div = DIV64_U64_ROUND_UP(period * pdata->pwm_refclk_freq,
1384 					     (u64)NSEC_PER_SEC * (BACKLIGHT_SCALE_MAX + 1));
1385 		scale = div64_u64(period * pdata->pwm_refclk_freq, (u64)NSEC_PER_SEC * pre_div) - 1;
1386 
1387 		/*
1388 		 * The documentation has the duty ratio given as:
1389 		 *
1390 		 *     duty          BACKLIGHT
1391 		 *   ------- = ---------------------
1392 		 *    period    BACKLIGHT_SCALE + 1
1393 		 *
1394 		 * Solve for BACKLIGHT, substituting BACKLIGHT_SCALE according
1395 		 * to definition above and adjusting for nanosecond
1396 		 * representation of duty cycle gives us:
1397 		 */
1398 		backlight = div64_u64(state->duty_cycle * pdata->pwm_refclk_freq,
1399 				      (u64)NSEC_PER_SEC * pre_div);
1400 		if (backlight > scale)
1401 			backlight = scale;
1402 
1403 		ret = regmap_write(pdata->regmap, SN_PWM_PRE_DIV_REG, pre_div);
1404 		if (ret) {
1405 			dev_err(pdata->dev, "failed to update PWM_PRE_DIV\n");
1406 			goto out;
1407 		}
1408 
1409 		ti_sn65dsi86_write_u16(pdata, SN_BACKLIGHT_SCALE_REG, scale);
1410 		ti_sn65dsi86_write_u16(pdata, SN_BACKLIGHT_REG, backlight);
1411 	}
1412 
1413 	pwm_en_inv = FIELD_PREP(SN_PWM_EN_MASK, state->enabled) |
1414 		     FIELD_PREP(SN_PWM_INV_MASK, state->polarity == PWM_POLARITY_INVERSED);
1415 	ret = regmap_write(pdata->regmap, SN_PWM_EN_INV_REG, pwm_en_inv);
1416 	if (ret) {
1417 		dev_err(pdata->dev, "failed to update PWM_EN/PWM_INV\n");
1418 		goto out;
1419 	}
1420 
1421 	pdata->pwm_enabled = state->enabled;
1422 out:
1423 
1424 	if (!pdata->pwm_enabled)
1425 		pm_runtime_put_sync(pdata->dev);
1426 
1427 	return ret;
1428 }
1429 
1430 static void ti_sn_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
1431 				struct pwm_state *state)
1432 {
1433 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1434 	unsigned int pwm_en_inv;
1435 	unsigned int pre_div;
1436 	u16 backlight;
1437 	u16 scale;
1438 	int ret;
1439 
1440 	ret = regmap_read(pdata->regmap, SN_PWM_EN_INV_REG, &pwm_en_inv);
1441 	if (ret)
1442 		return;
1443 
1444 	ret = ti_sn65dsi86_read_u16(pdata, SN_BACKLIGHT_SCALE_REG, &scale);
1445 	if (ret)
1446 		return;
1447 
1448 	ret = ti_sn65dsi86_read_u16(pdata, SN_BACKLIGHT_REG, &backlight);
1449 	if (ret)
1450 		return;
1451 
1452 	ret = regmap_read(pdata->regmap, SN_PWM_PRE_DIV_REG, &pre_div);
1453 	if (ret)
1454 		return;
1455 
1456 	state->enabled = FIELD_GET(SN_PWM_EN_MASK, pwm_en_inv);
1457 	if (FIELD_GET(SN_PWM_INV_MASK, pwm_en_inv))
1458 		state->polarity = PWM_POLARITY_INVERSED;
1459 	else
1460 		state->polarity = PWM_POLARITY_NORMAL;
1461 
1462 	state->period = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * pre_div * (scale + 1),
1463 					 pdata->pwm_refclk_freq);
1464 	state->duty_cycle = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * pre_div * backlight,
1465 					     pdata->pwm_refclk_freq);
1466 
1467 	if (state->duty_cycle > state->period)
1468 		state->duty_cycle = state->period;
1469 }
1470 
1471 static const struct pwm_ops ti_sn_pwm_ops = {
1472 	.request = ti_sn_pwm_request,
1473 	.free = ti_sn_pwm_free,
1474 	.apply = ti_sn_pwm_apply,
1475 	.get_state = ti_sn_pwm_get_state,
1476 	.owner = THIS_MODULE,
1477 };
1478 
1479 static int ti_sn_pwm_probe(struct auxiliary_device *adev,
1480 			   const struct auxiliary_device_id *id)
1481 {
1482 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1483 
1484 	pdata->pchip.dev = pdata->dev;
1485 	pdata->pchip.ops = &ti_sn_pwm_ops;
1486 	pdata->pchip.npwm = 1;
1487 	pdata->pchip.of_xlate = of_pwm_single_xlate;
1488 	pdata->pchip.of_pwm_n_cells = 1;
1489 
1490 	return pwmchip_add(&pdata->pchip);
1491 }
1492 
1493 static void ti_sn_pwm_remove(struct auxiliary_device *adev)
1494 {
1495 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1496 
1497 	pwmchip_remove(&pdata->pchip);
1498 
1499 	if (pdata->pwm_enabled)
1500 		pm_runtime_put_sync(pdata->dev);
1501 }
1502 
1503 static const struct auxiliary_device_id ti_sn_pwm_id_table[] = {
1504 	{ .name = "ti_sn65dsi86.pwm", },
1505 	{},
1506 };
1507 
1508 static struct auxiliary_driver ti_sn_pwm_driver = {
1509 	.name = "pwm",
1510 	.probe = ti_sn_pwm_probe,
1511 	.remove = ti_sn_pwm_remove,
1512 	.id_table = ti_sn_pwm_id_table,
1513 };
1514 
1515 static int __init ti_sn_pwm_register(void)
1516 {
1517 	return auxiliary_driver_register(&ti_sn_pwm_driver);
1518 }
1519 
1520 static void ti_sn_pwm_unregister(void)
1521 {
1522 	auxiliary_driver_unregister(&ti_sn_pwm_driver);
1523 }
1524 
1525 #else
1526 static inline int ti_sn_pwm_pin_request(struct ti_sn65dsi86 *pdata) { return 0; }
1527 static inline void ti_sn_pwm_pin_release(struct ti_sn65dsi86 *pdata) {}
1528 
1529 static inline int ti_sn_pwm_register(void) { return 0; }
1530 static inline void ti_sn_pwm_unregister(void) {}
1531 #endif
1532 
1533 /* -----------------------------------------------------------------------------
1534  * GPIO Controller
1535  */
1536 #if defined(CONFIG_OF_GPIO)
1537 
1538 static int tn_sn_bridge_of_xlate(struct gpio_chip *chip,
1539 				 const struct of_phandle_args *gpiospec,
1540 				 u32 *flags)
1541 {
1542 	if (WARN_ON(gpiospec->args_count < chip->of_gpio_n_cells))
1543 		return -EINVAL;
1544 
1545 	if (gpiospec->args[0] > chip->ngpio || gpiospec->args[0] < 1)
1546 		return -EINVAL;
1547 
1548 	if (flags)
1549 		*flags = gpiospec->args[1];
1550 
1551 	return gpiospec->args[0] - SN_GPIO_PHYSICAL_OFFSET;
1552 }
1553 
1554 static int ti_sn_bridge_gpio_get_direction(struct gpio_chip *chip,
1555 					   unsigned int offset)
1556 {
1557 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1558 
1559 	/*
1560 	 * We already have to keep track of the direction because we use
1561 	 * that to figure out whether we've powered the device.  We can
1562 	 * just return that rather than (maybe) powering up the device
1563 	 * to ask its direction.
1564 	 */
1565 	return test_bit(offset, pdata->gchip_output) ?
1566 		GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
1567 }
1568 
1569 static int ti_sn_bridge_gpio_get(struct gpio_chip *chip, unsigned int offset)
1570 {
1571 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1572 	unsigned int val;
1573 	int ret;
1574 
1575 	/*
1576 	 * When the pin is an input we don't forcibly keep the bridge
1577 	 * powered--we just power it on to read the pin.  NOTE: part of
1578 	 * the reason this works is that the bridge defaults (when
1579 	 * powered back on) to all 4 GPIOs being configured as GPIO input.
1580 	 * Also note that if something else is keeping the chip powered the
1581 	 * pm_runtime functions are lightweight increments of a refcount.
1582 	 */
1583 	pm_runtime_get_sync(pdata->dev);
1584 	ret = regmap_read(pdata->regmap, SN_GPIO_IO_REG, &val);
1585 	pm_runtime_put_autosuspend(pdata->dev);
1586 
1587 	if (ret)
1588 		return ret;
1589 
1590 	return !!(val & BIT(SN_GPIO_INPUT_SHIFT + offset));
1591 }
1592 
1593 static void ti_sn_bridge_gpio_set(struct gpio_chip *chip, unsigned int offset,
1594 				  int val)
1595 {
1596 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1597 	int ret;
1598 
1599 	if (!test_bit(offset, pdata->gchip_output)) {
1600 		dev_err(pdata->dev, "Ignoring GPIO set while input\n");
1601 		return;
1602 	}
1603 
1604 	val &= 1;
1605 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_IO_REG,
1606 				 BIT(SN_GPIO_OUTPUT_SHIFT + offset),
1607 				 val << (SN_GPIO_OUTPUT_SHIFT + offset));
1608 	if (ret)
1609 		dev_warn(pdata->dev,
1610 			 "Failed to set bridge GPIO %u: %d\n", offset, ret);
1611 }
1612 
1613 static int ti_sn_bridge_gpio_direction_input(struct gpio_chip *chip,
1614 					     unsigned int offset)
1615 {
1616 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1617 	int shift = offset * 2;
1618 	int ret;
1619 
1620 	if (!test_and_clear_bit(offset, pdata->gchip_output))
1621 		return 0;
1622 
1623 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1624 				 SN_GPIO_MUX_MASK << shift,
1625 				 SN_GPIO_MUX_INPUT << shift);
1626 	if (ret) {
1627 		set_bit(offset, pdata->gchip_output);
1628 		return ret;
1629 	}
1630 
1631 	/*
1632 	 * NOTE: if nobody else is powering the device this may fully power
1633 	 * it off and when it comes back it will have lost all state, but
1634 	 * that's OK because the default is input and we're now an input.
1635 	 */
1636 	pm_runtime_put_autosuspend(pdata->dev);
1637 
1638 	return 0;
1639 }
1640 
1641 static int ti_sn_bridge_gpio_direction_output(struct gpio_chip *chip,
1642 					      unsigned int offset, int val)
1643 {
1644 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1645 	int shift = offset * 2;
1646 	int ret;
1647 
1648 	if (test_and_set_bit(offset, pdata->gchip_output))
1649 		return 0;
1650 
1651 	pm_runtime_get_sync(pdata->dev);
1652 
1653 	/* Set value first to avoid glitching */
1654 	ti_sn_bridge_gpio_set(chip, offset, val);
1655 
1656 	/* Set direction */
1657 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1658 				 SN_GPIO_MUX_MASK << shift,
1659 				 SN_GPIO_MUX_OUTPUT << shift);
1660 	if (ret) {
1661 		clear_bit(offset, pdata->gchip_output);
1662 		pm_runtime_put_autosuspend(pdata->dev);
1663 	}
1664 
1665 	return ret;
1666 }
1667 
1668 static int ti_sn_bridge_gpio_request(struct gpio_chip *chip, unsigned int offset)
1669 {
1670 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1671 
1672 	if (offset == SN_PWM_GPIO_IDX)
1673 		return ti_sn_pwm_pin_request(pdata);
1674 
1675 	return 0;
1676 }
1677 
1678 static void ti_sn_bridge_gpio_free(struct gpio_chip *chip, unsigned int offset)
1679 {
1680 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1681 
1682 	/* We won't keep pm_runtime if we're input, so switch there on free */
1683 	ti_sn_bridge_gpio_direction_input(chip, offset);
1684 
1685 	if (offset == SN_PWM_GPIO_IDX)
1686 		ti_sn_pwm_pin_release(pdata);
1687 }
1688 
1689 static const char * const ti_sn_bridge_gpio_names[SN_NUM_GPIOS] = {
1690 	"GPIO1", "GPIO2", "GPIO3", "GPIO4"
1691 };
1692 
1693 static int ti_sn_gpio_probe(struct auxiliary_device *adev,
1694 			    const struct auxiliary_device_id *id)
1695 {
1696 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1697 	int ret;
1698 
1699 	/* Only init if someone is going to use us as a GPIO controller */
1700 	if (!of_property_read_bool(pdata->dev->of_node, "gpio-controller"))
1701 		return 0;
1702 
1703 	pdata->gchip.label = dev_name(pdata->dev);
1704 	pdata->gchip.parent = pdata->dev;
1705 	pdata->gchip.owner = THIS_MODULE;
1706 	pdata->gchip.of_xlate = tn_sn_bridge_of_xlate;
1707 	pdata->gchip.of_gpio_n_cells = 2;
1708 	pdata->gchip.request = ti_sn_bridge_gpio_request;
1709 	pdata->gchip.free = ti_sn_bridge_gpio_free;
1710 	pdata->gchip.get_direction = ti_sn_bridge_gpio_get_direction;
1711 	pdata->gchip.direction_input = ti_sn_bridge_gpio_direction_input;
1712 	pdata->gchip.direction_output = ti_sn_bridge_gpio_direction_output;
1713 	pdata->gchip.get = ti_sn_bridge_gpio_get;
1714 	pdata->gchip.set = ti_sn_bridge_gpio_set;
1715 	pdata->gchip.can_sleep = true;
1716 	pdata->gchip.names = ti_sn_bridge_gpio_names;
1717 	pdata->gchip.ngpio = SN_NUM_GPIOS;
1718 	pdata->gchip.base = -1;
1719 	ret = devm_gpiochip_add_data(&adev->dev, &pdata->gchip, pdata);
1720 	if (ret)
1721 		dev_err(pdata->dev, "can't add gpio chip\n");
1722 
1723 	return ret;
1724 }
1725 
1726 static const struct auxiliary_device_id ti_sn_gpio_id_table[] = {
1727 	{ .name = "ti_sn65dsi86.gpio", },
1728 	{},
1729 };
1730 
1731 MODULE_DEVICE_TABLE(auxiliary, ti_sn_gpio_id_table);
1732 
1733 static struct auxiliary_driver ti_sn_gpio_driver = {
1734 	.name = "gpio",
1735 	.probe = ti_sn_gpio_probe,
1736 	.id_table = ti_sn_gpio_id_table,
1737 };
1738 
1739 static int __init ti_sn_gpio_register(void)
1740 {
1741 	return auxiliary_driver_register(&ti_sn_gpio_driver);
1742 }
1743 
1744 static void ti_sn_gpio_unregister(void)
1745 {
1746 	auxiliary_driver_unregister(&ti_sn_gpio_driver);
1747 }
1748 
1749 #else
1750 
1751 static inline int ti_sn_gpio_register(void) { return 0; }
1752 static inline void ti_sn_gpio_unregister(void) {}
1753 
1754 #endif
1755 
1756 /* -----------------------------------------------------------------------------
1757  * Probe & Remove
1758  */
1759 
1760 static void ti_sn65dsi86_runtime_disable(void *data)
1761 {
1762 	pm_runtime_dont_use_autosuspend(data);
1763 	pm_runtime_disable(data);
1764 }
1765 
1766 static int ti_sn65dsi86_parse_regulators(struct ti_sn65dsi86 *pdata)
1767 {
1768 	unsigned int i;
1769 	const char * const ti_sn_bridge_supply_names[] = {
1770 		"vcca", "vcc", "vccio", "vpll",
1771 	};
1772 
1773 	for (i = 0; i < SN_REGULATOR_SUPPLY_NUM; i++)
1774 		pdata->supplies[i].supply = ti_sn_bridge_supply_names[i];
1775 
1776 	return devm_regulator_bulk_get(pdata->dev, SN_REGULATOR_SUPPLY_NUM,
1777 				       pdata->supplies);
1778 }
1779 
1780 static int ti_sn65dsi86_probe(struct i2c_client *client,
1781 			      const struct i2c_device_id *id)
1782 {
1783 	struct device *dev = &client->dev;
1784 	struct ti_sn65dsi86 *pdata;
1785 	int ret;
1786 
1787 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1788 		DRM_ERROR("device doesn't support I2C\n");
1789 		return -ENODEV;
1790 	}
1791 
1792 	pdata = devm_kzalloc(dev, sizeof(struct ti_sn65dsi86), GFP_KERNEL);
1793 	if (!pdata)
1794 		return -ENOMEM;
1795 	dev_set_drvdata(dev, pdata);
1796 	pdata->dev = dev;
1797 
1798 	mutex_init(&pdata->comms_mutex);
1799 
1800 	pdata->regmap = devm_regmap_init_i2c(client,
1801 					     &ti_sn65dsi86_regmap_config);
1802 	if (IS_ERR(pdata->regmap))
1803 		return dev_err_probe(dev, PTR_ERR(pdata->regmap),
1804 				     "regmap i2c init failed\n");
1805 
1806 	pdata->enable_gpio = devm_gpiod_get_optional(dev, "enable",
1807 						     GPIOD_OUT_LOW);
1808 	if (IS_ERR(pdata->enable_gpio))
1809 		return dev_err_probe(dev, PTR_ERR(pdata->enable_gpio),
1810 				     "failed to get enable gpio from DT\n");
1811 
1812 	ret = ti_sn65dsi86_parse_regulators(pdata);
1813 	if (ret)
1814 		return dev_err_probe(dev, ret, "failed to parse regulators\n");
1815 
1816 	pdata->refclk = devm_clk_get_optional(dev, "refclk");
1817 	if (IS_ERR(pdata->refclk))
1818 		return dev_err_probe(dev, PTR_ERR(pdata->refclk),
1819 				     "failed to get reference clock\n");
1820 
1821 	pm_runtime_enable(dev);
1822 	pm_runtime_set_autosuspend_delay(pdata->dev, 500);
1823 	pm_runtime_use_autosuspend(pdata->dev);
1824 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_runtime_disable, dev);
1825 	if (ret)
1826 		return ret;
1827 
1828 	ti_sn65dsi86_debugfs_init(pdata);
1829 
1830 	/*
1831 	 * Break ourselves up into a collection of aux devices. The only real
1832 	 * motiviation here is to solve the chicken-and-egg problem of probe
1833 	 * ordering. The bridge wants the panel to be there when it probes.
1834 	 * The panel wants its HPD GPIO (provided by sn65dsi86 on some boards)
1835 	 * when it probes. The panel and maybe backlight might want the DDC
1836 	 * bus or the pwm_chip. Having sub-devices allows the some sub devices
1837 	 * to finish probing even if others return -EPROBE_DEFER and gets us
1838 	 * around the problems.
1839 	 */
1840 
1841 	if (IS_ENABLED(CONFIG_OF_GPIO)) {
1842 		ret = ti_sn65dsi86_add_aux_device(pdata, &pdata->gpio_aux, "gpio");
1843 		if (ret)
1844 			return ret;
1845 	}
1846 
1847 	if (IS_ENABLED(CONFIG_PWM)) {
1848 		ret = ti_sn65dsi86_add_aux_device(pdata, &pdata->pwm_aux, "pwm");
1849 		if (ret)
1850 			return ret;
1851 	}
1852 
1853 	/*
1854 	 * NOTE: At the end of the AUX channel probe we'll add the aux device
1855 	 * for the bridge. This is because the bridge can't be used until the
1856 	 * AUX channel is there and this is a very simple solution to the
1857 	 * dependency problem.
1858 	 */
1859 	return ti_sn65dsi86_add_aux_device(pdata, &pdata->aux_aux, "aux");
1860 }
1861 
1862 static struct i2c_device_id ti_sn65dsi86_id[] = {
1863 	{ "ti,sn65dsi86", 0},
1864 	{},
1865 };
1866 MODULE_DEVICE_TABLE(i2c, ti_sn65dsi86_id);
1867 
1868 static const struct of_device_id ti_sn65dsi86_match_table[] = {
1869 	{.compatible = "ti,sn65dsi86"},
1870 	{},
1871 };
1872 MODULE_DEVICE_TABLE(of, ti_sn65dsi86_match_table);
1873 
1874 static struct i2c_driver ti_sn65dsi86_driver = {
1875 	.driver = {
1876 		.name = "ti_sn65dsi86",
1877 		.of_match_table = ti_sn65dsi86_match_table,
1878 		.pm = &ti_sn65dsi86_pm_ops,
1879 	},
1880 	.probe = ti_sn65dsi86_probe,
1881 	.id_table = ti_sn65dsi86_id,
1882 };
1883 
1884 static int __init ti_sn65dsi86_init(void)
1885 {
1886 	int ret;
1887 
1888 	ret = i2c_add_driver(&ti_sn65dsi86_driver);
1889 	if (ret)
1890 		return ret;
1891 
1892 	ret = ti_sn_gpio_register();
1893 	if (ret)
1894 		goto err_main_was_registered;
1895 
1896 	ret = ti_sn_pwm_register();
1897 	if (ret)
1898 		goto err_gpio_was_registered;
1899 
1900 	ret = auxiliary_driver_register(&ti_sn_aux_driver);
1901 	if (ret)
1902 		goto err_pwm_was_registered;
1903 
1904 	ret = auxiliary_driver_register(&ti_sn_bridge_driver);
1905 	if (ret)
1906 		goto err_aux_was_registered;
1907 
1908 	return 0;
1909 
1910 err_aux_was_registered:
1911 	auxiliary_driver_unregister(&ti_sn_aux_driver);
1912 err_pwm_was_registered:
1913 	ti_sn_pwm_unregister();
1914 err_gpio_was_registered:
1915 	ti_sn_gpio_unregister();
1916 err_main_was_registered:
1917 	i2c_del_driver(&ti_sn65dsi86_driver);
1918 
1919 	return ret;
1920 }
1921 module_init(ti_sn65dsi86_init);
1922 
1923 static void __exit ti_sn65dsi86_exit(void)
1924 {
1925 	auxiliary_driver_unregister(&ti_sn_bridge_driver);
1926 	auxiliary_driver_unregister(&ti_sn_aux_driver);
1927 	ti_sn_pwm_unregister();
1928 	ti_sn_gpio_unregister();
1929 	i2c_del_driver(&ti_sn65dsi86_driver);
1930 }
1931 module_exit(ti_sn65dsi86_exit);
1932 
1933 MODULE_AUTHOR("Sandeep Panda <spanda@codeaurora.org>");
1934 MODULE_DESCRIPTION("sn65dsi86 DSI to eDP bridge driver");
1935 MODULE_LICENSE("GPL v2");
1936