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_edid.h>
33 #include <drm/drm_mipi_dsi.h>
34 #include <drm/drm_of.h>
35 #include <drm/drm_panel.h>
36 #include <drm/drm_print.h>
37 #include <drm/drm_probe_helper.h>
38 
39 #define SN_DEVICE_REV_REG			0x08
40 #define SN_DPPLL_SRC_REG			0x0A
41 #define  DPPLL_CLK_SRC_DSICLK			BIT(0)
42 #define  REFCLK_FREQ_MASK			GENMASK(3, 1)
43 #define  REFCLK_FREQ(x)				((x) << 1)
44 #define  DPPLL_SRC_DP_PLL_LOCK			BIT(7)
45 #define SN_PLL_ENABLE_REG			0x0D
46 #define SN_DSI_LANES_REG			0x10
47 #define  CHA_DSI_LANES_MASK			GENMASK(4, 3)
48 #define  CHA_DSI_LANES(x)			((x) << 3)
49 #define SN_DSIA_CLK_FREQ_REG			0x12
50 #define SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG	0x20
51 #define SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG	0x24
52 #define SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG	0x2C
53 #define SN_CHA_HSYNC_PULSE_WIDTH_HIGH_REG	0x2D
54 #define  CHA_HSYNC_POLARITY			BIT(7)
55 #define SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG	0x30
56 #define SN_CHA_VSYNC_PULSE_WIDTH_HIGH_REG	0x31
57 #define  CHA_VSYNC_POLARITY			BIT(7)
58 #define SN_CHA_HORIZONTAL_BACK_PORCH_REG	0x34
59 #define SN_CHA_VERTICAL_BACK_PORCH_REG		0x36
60 #define SN_CHA_HORIZONTAL_FRONT_PORCH_REG	0x38
61 #define SN_CHA_VERTICAL_FRONT_PORCH_REG		0x3A
62 #define SN_LN_ASSIGN_REG			0x59
63 #define  LN_ASSIGN_WIDTH			2
64 #define SN_ENH_FRAME_REG			0x5A
65 #define  VSTREAM_ENABLE				BIT(3)
66 #define  LN_POLRS_OFFSET			4
67 #define  LN_POLRS_MASK				0xf0
68 #define SN_DATA_FORMAT_REG			0x5B
69 #define  BPP_18_RGB				BIT(0)
70 #define SN_HPD_DISABLE_REG			0x5C
71 #define  HPD_DISABLE				BIT(0)
72 #define  HPD_DEBOUNCED_STATE			BIT(4)
73 #define SN_GPIO_IO_REG				0x5E
74 #define  SN_GPIO_INPUT_SHIFT			4
75 #define  SN_GPIO_OUTPUT_SHIFT			0
76 #define SN_GPIO_CTRL_REG			0x5F
77 #define  SN_GPIO_MUX_INPUT			0
78 #define  SN_GPIO_MUX_OUTPUT			1
79 #define  SN_GPIO_MUX_SPECIAL			2
80 #define  SN_GPIO_MUX_MASK			0x3
81 #define SN_AUX_WDATA_REG(x)			(0x64 + (x))
82 #define SN_AUX_ADDR_19_16_REG			0x74
83 #define SN_AUX_ADDR_15_8_REG			0x75
84 #define SN_AUX_ADDR_7_0_REG			0x76
85 #define SN_AUX_ADDR_MASK			GENMASK(19, 0)
86 #define SN_AUX_LENGTH_REG			0x77
87 #define SN_AUX_CMD_REG				0x78
88 #define  AUX_CMD_SEND				BIT(0)
89 #define  AUX_CMD_REQ(x)				((x) << 4)
90 #define SN_AUX_RDATA_REG(x)			(0x79 + (x))
91 #define SN_SSC_CONFIG_REG			0x93
92 #define  DP_NUM_LANES_MASK			GENMASK(5, 4)
93 #define  DP_NUM_LANES(x)			((x) << 4)
94 #define SN_DATARATE_CONFIG_REG			0x94
95 #define  DP_DATARATE_MASK			GENMASK(7, 5)
96 #define  DP_DATARATE(x)				((x) << 5)
97 #define SN_TRAINING_SETTING_REG			0x95
98 #define  SCRAMBLE_DISABLE			BIT(4)
99 #define SN_ML_TX_MODE_REG			0x96
100 #define  ML_TX_MAIN_LINK_OFF			0
101 #define  ML_TX_NORMAL_MODE			BIT(0)
102 #define SN_PWM_PRE_DIV_REG			0xA0
103 #define SN_BACKLIGHT_SCALE_REG			0xA1
104 #define  BACKLIGHT_SCALE_MAX			0xFFFF
105 #define SN_BACKLIGHT_REG			0xA3
106 #define SN_PWM_EN_INV_REG			0xA5
107 #define  SN_PWM_INV_MASK			BIT(0)
108 #define  SN_PWM_EN_MASK				BIT(1)
109 #define SN_AUX_CMD_STATUS_REG			0xF4
110 #define  AUX_IRQ_STATUS_AUX_RPLY_TOUT		BIT(3)
111 #define  AUX_IRQ_STATUS_AUX_SHORT		BIT(5)
112 #define  AUX_IRQ_STATUS_NAT_I2C_FAIL		BIT(6)
113 
114 #define MIN_DSI_CLK_FREQ_MHZ	40
115 
116 /* fudge factor required to account for 8b/10b encoding */
117 #define DP_CLK_FUDGE_NUM	10
118 #define DP_CLK_FUDGE_DEN	8
119 
120 /* Matches DP_AUX_MAX_PAYLOAD_BYTES (for now) */
121 #define SN_AUX_MAX_PAYLOAD_BYTES	16
122 
123 #define SN_REGULATOR_SUPPLY_NUM		4
124 
125 #define SN_MAX_DP_LANES			4
126 #define SN_NUM_GPIOS			4
127 #define SN_GPIO_PHYSICAL_OFFSET		1
128 
129 #define SN_LINK_TRAINING_TRIES		10
130 
131 #define SN_PWM_GPIO_IDX			3 /* 4th GPIO */
132 
133 /**
134  * struct ti_sn65dsi86 - Platform data for ti-sn65dsi86 driver.
135  * @bridge_aux:   AUX-bus sub device for MIPI-to-eDP bridge functionality.
136  * @gpio_aux:     AUX-bus sub device for GPIO controller functionality.
137  * @aux_aux:      AUX-bus sub device for eDP AUX channel functionality.
138  * @pwm_aux:      AUX-bus sub device for PWM controller functionality.
139  *
140  * @dev:          Pointer to the top level (i2c) device.
141  * @regmap:       Regmap for accessing i2c.
142  * @aux:          Our aux channel.
143  * @bridge:       Our bridge.
144  * @connector:    Our connector.
145  * @host_node:    Remote DSI node.
146  * @dsi:          Our MIPI DSI source.
147  * @refclk:       Our reference clock.
148  * @next_bridge:  The bridge on the eDP side.
149  * @enable_gpio:  The GPIO we toggle to enable the bridge.
150  * @supplies:     Data for bulk enabling/disabling our regulators.
151  * @dp_lanes:     Count of dp_lanes we're using.
152  * @ln_assign:    Value to program to the LN_ASSIGN register.
153  * @ln_polrs:     Value for the 4-bit LN_POLRS field of SN_ENH_FRAME_REG.
154  * @comms_enabled: If true then communication over the aux channel is enabled.
155  * @comms_mutex:   Protects modification of comms_enabled.
156  *
157  * @gchip:        If we expose our GPIOs, this is used.
158  * @gchip_output: A cache of whether we've set GPIOs to output.  This
159  *                serves double-duty of keeping track of the direction and
160  *                also keeping track of whether we've incremented the
161  *                pm_runtime reference count for this pin, which we do
162  *                whenever a pin is configured as an output.  This is a
163  *                bitmap so we can do atomic ops on it without an extra
164  *                lock so concurrent users of our 4 GPIOs don't stomp on
165  *                each other's read-modify-write.
166  *
167  * @pchip:        pwm_chip if the PWM is exposed.
168  * @pwm_enabled:  Used to track if the PWM signal is currently enabled.
169  * @pwm_pin_busy: Track if GPIO4 is currently requested for GPIO or PWM.
170  * @pwm_refclk_freq: Cache for the reference clock input to the PWM.
171  */
172 struct ti_sn65dsi86 {
173 	struct auxiliary_device		bridge_aux;
174 	struct auxiliary_device		gpio_aux;
175 	struct auxiliary_device		aux_aux;
176 	struct auxiliary_device		pwm_aux;
177 
178 	struct device			*dev;
179 	struct regmap			*regmap;
180 	struct drm_dp_aux		aux;
181 	struct drm_bridge		bridge;
182 	struct drm_connector		*connector;
183 	struct device_node		*host_node;
184 	struct mipi_dsi_device		*dsi;
185 	struct clk			*refclk;
186 	struct drm_bridge		*next_bridge;
187 	struct gpio_desc		*enable_gpio;
188 	struct regulator_bulk_data	supplies[SN_REGULATOR_SUPPLY_NUM];
189 	int				dp_lanes;
190 	u8				ln_assign;
191 	u8				ln_polrs;
192 	bool				comms_enabled;
193 	struct mutex			comms_mutex;
194 
195 #if defined(CONFIG_OF_GPIO)
196 	struct gpio_chip		gchip;
197 	DECLARE_BITMAP(gchip_output, SN_NUM_GPIOS);
198 #endif
199 #if defined(CONFIG_PWM)
200 	struct pwm_chip			pchip;
201 	bool				pwm_enabled;
202 	atomic_t			pwm_pin_busy;
203 #endif
204 	unsigned int			pwm_refclk_freq;
205 };
206 
207 static const struct regmap_range ti_sn65dsi86_volatile_ranges[] = {
208 	{ .range_min = 0, .range_max = 0xFF },
209 };
210 
211 static const struct regmap_access_table ti_sn_bridge_volatile_table = {
212 	.yes_ranges = ti_sn65dsi86_volatile_ranges,
213 	.n_yes_ranges = ARRAY_SIZE(ti_sn65dsi86_volatile_ranges),
214 };
215 
216 static const struct regmap_config ti_sn65dsi86_regmap_config = {
217 	.reg_bits = 8,
218 	.val_bits = 8,
219 	.volatile_table = &ti_sn_bridge_volatile_table,
220 	.cache_type = REGCACHE_NONE,
221 	.max_register = 0xFF,
222 };
223 
224 static int __maybe_unused ti_sn65dsi86_read_u16(struct ti_sn65dsi86 *pdata,
225 						unsigned int reg, u16 *val)
226 {
227 	u8 buf[2];
228 	int ret;
229 
230 	ret = regmap_bulk_read(pdata->regmap, reg, buf, ARRAY_SIZE(buf));
231 	if (ret)
232 		return ret;
233 
234 	*val = buf[0] | (buf[1] << 8);
235 
236 	return 0;
237 }
238 
239 static void ti_sn65dsi86_write_u16(struct ti_sn65dsi86 *pdata,
240 				   unsigned int reg, u16 val)
241 {
242 	u8 buf[2] = { val & 0xff, val >> 8 };
243 
244 	regmap_bulk_write(pdata->regmap, reg, buf, ARRAY_SIZE(buf));
245 }
246 
247 static u32 ti_sn_bridge_get_dsi_freq(struct ti_sn65dsi86 *pdata)
248 {
249 	u32 bit_rate_khz, clk_freq_khz;
250 	struct drm_display_mode *mode =
251 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
252 
253 	bit_rate_khz = mode->clock *
254 			mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
255 	clk_freq_khz = bit_rate_khz / (pdata->dsi->lanes * 2);
256 
257 	return clk_freq_khz;
258 }
259 
260 /* clk frequencies supported by bridge in Hz in case derived from REFCLK pin */
261 static const u32 ti_sn_bridge_refclk_lut[] = {
262 	12000000,
263 	19200000,
264 	26000000,
265 	27000000,
266 	38400000,
267 };
268 
269 /* clk frequencies supported by bridge in Hz in case derived from DACP/N pin */
270 static const u32 ti_sn_bridge_dsiclk_lut[] = {
271 	468000000,
272 	384000000,
273 	416000000,
274 	486000000,
275 	460800000,
276 };
277 
278 static void ti_sn_bridge_set_refclk_freq(struct ti_sn65dsi86 *pdata)
279 {
280 	int i;
281 	u32 refclk_rate;
282 	const u32 *refclk_lut;
283 	size_t refclk_lut_size;
284 
285 	if (pdata->refclk) {
286 		refclk_rate = clk_get_rate(pdata->refclk);
287 		refclk_lut = ti_sn_bridge_refclk_lut;
288 		refclk_lut_size = ARRAY_SIZE(ti_sn_bridge_refclk_lut);
289 		clk_prepare_enable(pdata->refclk);
290 	} else {
291 		refclk_rate = ti_sn_bridge_get_dsi_freq(pdata) * 1000;
292 		refclk_lut = ti_sn_bridge_dsiclk_lut;
293 		refclk_lut_size = ARRAY_SIZE(ti_sn_bridge_dsiclk_lut);
294 	}
295 
296 	/* for i equals to refclk_lut_size means default frequency */
297 	for (i = 0; i < refclk_lut_size; i++)
298 		if (refclk_lut[i] == refclk_rate)
299 			break;
300 
301 	regmap_update_bits(pdata->regmap, SN_DPPLL_SRC_REG, REFCLK_FREQ_MASK,
302 			   REFCLK_FREQ(i));
303 
304 	/*
305 	 * The PWM refclk is based on the value written to SN_DPPLL_SRC_REG,
306 	 * regardless of its actual sourcing.
307 	 */
308 	pdata->pwm_refclk_freq = ti_sn_bridge_refclk_lut[i];
309 }
310 
311 static void ti_sn65dsi86_enable_comms(struct ti_sn65dsi86 *pdata)
312 {
313 	mutex_lock(&pdata->comms_mutex);
314 
315 	/* configure bridge ref_clk */
316 	ti_sn_bridge_set_refclk_freq(pdata);
317 
318 	/*
319 	 * HPD on this bridge chip is a bit useless.  This is an eDP bridge
320 	 * so the HPD is an internal signal that's only there to signal that
321 	 * the panel is done powering up.  ...but the bridge chip debounces
322 	 * this signal by between 100 ms and 400 ms (depending on process,
323 	 * voltage, and temperate--I measured it at about 200 ms).  One
324 	 * particular panel asserted HPD 84 ms after it was powered on meaning
325 	 * that we saw HPD 284 ms after power on.  ...but the same panel said
326 	 * that instead of looking at HPD you could just hardcode a delay of
327 	 * 200 ms.  We'll assume that the panel driver will have the hardcoded
328 	 * delay in its prepare and always disable HPD.
329 	 *
330 	 * If HPD somehow makes sense on some future panel we'll have to
331 	 * change this to be conditional on someone specifying that HPD should
332 	 * be used.
333 	 */
334 	regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE,
335 			   HPD_DISABLE);
336 
337 	pdata->comms_enabled = true;
338 
339 	mutex_unlock(&pdata->comms_mutex);
340 }
341 
342 static void ti_sn65dsi86_disable_comms(struct ti_sn65dsi86 *pdata)
343 {
344 	mutex_lock(&pdata->comms_mutex);
345 
346 	pdata->comms_enabled = false;
347 	clk_disable_unprepare(pdata->refclk);
348 
349 	mutex_unlock(&pdata->comms_mutex);
350 }
351 
352 static int __maybe_unused ti_sn65dsi86_resume(struct device *dev)
353 {
354 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(dev);
355 	int ret;
356 
357 	ret = regulator_bulk_enable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies);
358 	if (ret) {
359 		DRM_ERROR("failed to enable supplies %d\n", ret);
360 		return ret;
361 	}
362 
363 	/* td2: min 100 us after regulators before enabling the GPIO */
364 	usleep_range(100, 110);
365 
366 	gpiod_set_value(pdata->enable_gpio, 1);
367 
368 	/*
369 	 * If we have a reference clock we can enable communication w/ the
370 	 * panel (including the aux channel) w/out any need for an input clock
371 	 * so we can do it in resume which lets us read the EDID before
372 	 * pre_enable(). Without a reference clock we need the MIPI reference
373 	 * clock so reading early doesn't work.
374 	 */
375 	if (pdata->refclk)
376 		ti_sn65dsi86_enable_comms(pdata);
377 
378 	return ret;
379 }
380 
381 static int __maybe_unused ti_sn65dsi86_suspend(struct device *dev)
382 {
383 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(dev);
384 	int ret;
385 
386 	if (pdata->refclk)
387 		ti_sn65dsi86_disable_comms(pdata);
388 
389 	gpiod_set_value(pdata->enable_gpio, 0);
390 
391 	ret = regulator_bulk_disable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies);
392 	if (ret)
393 		DRM_ERROR("failed to disable supplies %d\n", ret);
394 
395 	return ret;
396 }
397 
398 static const struct dev_pm_ops ti_sn65dsi86_pm_ops = {
399 	SET_RUNTIME_PM_OPS(ti_sn65dsi86_suspend, ti_sn65dsi86_resume, NULL)
400 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
401 				pm_runtime_force_resume)
402 };
403 
404 static int status_show(struct seq_file *s, void *data)
405 {
406 	struct ti_sn65dsi86 *pdata = s->private;
407 	unsigned int reg, val;
408 
409 	seq_puts(s, "STATUS REGISTERS:\n");
410 
411 	pm_runtime_get_sync(pdata->dev);
412 
413 	/* IRQ Status Registers, see Table 31 in datasheet */
414 	for (reg = 0xf0; reg <= 0xf8; reg++) {
415 		regmap_read(pdata->regmap, reg, &val);
416 		seq_printf(s, "[0x%02x] = 0x%08x\n", reg, val);
417 	}
418 
419 	pm_runtime_put_autosuspend(pdata->dev);
420 
421 	return 0;
422 }
423 
424 DEFINE_SHOW_ATTRIBUTE(status);
425 
426 static void ti_sn65dsi86_debugfs_remove(void *data)
427 {
428 	debugfs_remove_recursive(data);
429 }
430 
431 static void ti_sn65dsi86_debugfs_init(struct ti_sn65dsi86 *pdata)
432 {
433 	struct device *dev = pdata->dev;
434 	struct dentry *debugfs;
435 	int ret;
436 
437 	debugfs = debugfs_create_dir(dev_name(dev), NULL);
438 
439 	/*
440 	 * We might get an error back if debugfs wasn't enabled in the kernel
441 	 * so let's just silently return upon failure.
442 	 */
443 	if (IS_ERR_OR_NULL(debugfs))
444 		return;
445 
446 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_debugfs_remove, debugfs);
447 	if (ret)
448 		return;
449 
450 	debugfs_create_file("status", 0600, debugfs, pdata, &status_fops);
451 }
452 
453 /* -----------------------------------------------------------------------------
454  * Auxiliary Devices (*not* AUX)
455  */
456 
457 static void ti_sn65dsi86_uninit_aux(void *data)
458 {
459 	auxiliary_device_uninit(data);
460 }
461 
462 static void ti_sn65dsi86_delete_aux(void *data)
463 {
464 	auxiliary_device_delete(data);
465 }
466 
467 /*
468  * AUX bus docs say that a non-NULL release is mandatory, but it makes no
469  * sense for the model used here where all of the aux devices are allocated
470  * in the single shared structure. We'll use this noop as a workaround.
471  */
472 static void ti_sn65dsi86_noop(struct device *dev) {}
473 
474 static int ti_sn65dsi86_add_aux_device(struct ti_sn65dsi86 *pdata,
475 				       struct auxiliary_device *aux,
476 				       const char *name)
477 {
478 	struct device *dev = pdata->dev;
479 	int ret;
480 
481 	aux->name = name;
482 	aux->dev.parent = dev;
483 	aux->dev.release = ti_sn65dsi86_noop;
484 	device_set_of_node_from_dev(&aux->dev, dev);
485 	ret = auxiliary_device_init(aux);
486 	if (ret)
487 		return ret;
488 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_uninit_aux, aux);
489 	if (ret)
490 		return ret;
491 
492 	ret = auxiliary_device_add(aux);
493 	if (ret)
494 		return ret;
495 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_delete_aux, aux);
496 
497 	return ret;
498 }
499 
500 /* -----------------------------------------------------------------------------
501  * AUX Adapter
502  */
503 
504 static struct ti_sn65dsi86 *aux_to_ti_sn65dsi86(struct drm_dp_aux *aux)
505 {
506 	return container_of(aux, struct ti_sn65dsi86, aux);
507 }
508 
509 static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux,
510 				  struct drm_dp_aux_msg *msg)
511 {
512 	struct ti_sn65dsi86 *pdata = aux_to_ti_sn65dsi86(aux);
513 	u32 request = msg->request & ~(DP_AUX_I2C_MOT | DP_AUX_I2C_WRITE_STATUS_UPDATE);
514 	u32 request_val = AUX_CMD_REQ(msg->request);
515 	u8 *buf = msg->buffer;
516 	unsigned int len = msg->size;
517 	unsigned int val;
518 	int ret;
519 	u8 addr_len[SN_AUX_LENGTH_REG + 1 - SN_AUX_ADDR_19_16_REG];
520 
521 	if (len > SN_AUX_MAX_PAYLOAD_BYTES)
522 		return -EINVAL;
523 
524 	pm_runtime_get_sync(pdata->dev);
525 	mutex_lock(&pdata->comms_mutex);
526 
527 	/*
528 	 * If someone tries to do a DDC over AUX transaction before pre_enable()
529 	 * on a device without a dedicated reference clock then we just can't
530 	 * do it. Fail right away. This prevents non-refclk users from reading
531 	 * the EDID before enabling the panel but such is life.
532 	 */
533 	if (!pdata->comms_enabled) {
534 		ret = -EIO;
535 		goto exit;
536 	}
537 
538 	switch (request) {
539 	case DP_AUX_NATIVE_WRITE:
540 	case DP_AUX_I2C_WRITE:
541 	case DP_AUX_NATIVE_READ:
542 	case DP_AUX_I2C_READ:
543 		regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val);
544 		/* Assume it's good */
545 		msg->reply = 0;
546 		break;
547 	default:
548 		ret = -EINVAL;
549 		goto exit;
550 	}
551 
552 	BUILD_BUG_ON(sizeof(addr_len) != sizeof(__be32));
553 	put_unaligned_be32((msg->address & SN_AUX_ADDR_MASK) << 8 | len,
554 			   addr_len);
555 	regmap_bulk_write(pdata->regmap, SN_AUX_ADDR_19_16_REG, addr_len,
556 			  ARRAY_SIZE(addr_len));
557 
558 	if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE)
559 		regmap_bulk_write(pdata->regmap, SN_AUX_WDATA_REG(0), buf, len);
560 
561 	/* Clear old status bits before start so we don't get confused */
562 	regmap_write(pdata->regmap, SN_AUX_CMD_STATUS_REG,
563 		     AUX_IRQ_STATUS_NAT_I2C_FAIL |
564 		     AUX_IRQ_STATUS_AUX_RPLY_TOUT |
565 		     AUX_IRQ_STATUS_AUX_SHORT);
566 
567 	regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val | AUX_CMD_SEND);
568 
569 	/* Zero delay loop because i2c transactions are slow already */
570 	ret = regmap_read_poll_timeout(pdata->regmap, SN_AUX_CMD_REG, val,
571 				       !(val & AUX_CMD_SEND), 0, 50 * 1000);
572 	if (ret)
573 		goto exit;
574 
575 	ret = regmap_read(pdata->regmap, SN_AUX_CMD_STATUS_REG, &val);
576 	if (ret)
577 		goto exit;
578 
579 	if (val & AUX_IRQ_STATUS_AUX_RPLY_TOUT) {
580 		/*
581 		 * The hardware tried the message seven times per the DP spec
582 		 * but it hit a timeout. We ignore defers here because they're
583 		 * handled in hardware.
584 		 */
585 		ret = -ETIMEDOUT;
586 		goto exit;
587 	}
588 
589 	if (val & AUX_IRQ_STATUS_AUX_SHORT) {
590 		ret = regmap_read(pdata->regmap, SN_AUX_LENGTH_REG, &len);
591 		if (ret)
592 			goto exit;
593 	} else if (val & AUX_IRQ_STATUS_NAT_I2C_FAIL) {
594 		switch (request) {
595 		case DP_AUX_I2C_WRITE:
596 		case DP_AUX_I2C_READ:
597 			msg->reply |= DP_AUX_I2C_REPLY_NACK;
598 			break;
599 		case DP_AUX_NATIVE_READ:
600 		case DP_AUX_NATIVE_WRITE:
601 			msg->reply |= DP_AUX_NATIVE_REPLY_NACK;
602 			break;
603 		}
604 		len = 0;
605 		goto exit;
606 	}
607 
608 	if (request != DP_AUX_NATIVE_WRITE && request != DP_AUX_I2C_WRITE && len != 0)
609 		ret = regmap_bulk_read(pdata->regmap, SN_AUX_RDATA_REG(0), buf, len);
610 
611 exit:
612 	mutex_unlock(&pdata->comms_mutex);
613 	pm_runtime_mark_last_busy(pdata->dev);
614 	pm_runtime_put_autosuspend(pdata->dev);
615 
616 	if (ret)
617 		return ret;
618 	return len;
619 }
620 
621 static int ti_sn_aux_probe(struct auxiliary_device *adev,
622 			   const struct auxiliary_device_id *id)
623 {
624 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
625 	int ret;
626 
627 	pdata->aux.name = "ti-sn65dsi86-aux";
628 	pdata->aux.dev = &adev->dev;
629 	pdata->aux.transfer = ti_sn_aux_transfer;
630 	drm_dp_aux_init(&pdata->aux);
631 
632 	ret = devm_of_dp_aux_populate_ep_devices(&pdata->aux);
633 	if (ret)
634 		return ret;
635 
636 	/*
637 	 * The eDP to MIPI bridge parts don't work until the AUX channel is
638 	 * setup so we don't add it in the main driver probe, we add it now.
639 	 */
640 	return ti_sn65dsi86_add_aux_device(pdata, &pdata->bridge_aux, "bridge");
641 }
642 
643 static const struct auxiliary_device_id ti_sn_aux_id_table[] = {
644 	{ .name = "ti_sn65dsi86.aux", },
645 	{},
646 };
647 
648 static struct auxiliary_driver ti_sn_aux_driver = {
649 	.name = "aux",
650 	.probe = ti_sn_aux_probe,
651 	.id_table = ti_sn_aux_id_table,
652 };
653 
654 /*------------------------------------------------------------------------------
655  * DRM Bridge
656  */
657 
658 static struct ti_sn65dsi86 *bridge_to_ti_sn65dsi86(struct drm_bridge *bridge)
659 {
660 	return container_of(bridge, struct ti_sn65dsi86, bridge);
661 }
662 
663 static int ti_sn_attach_host(struct ti_sn65dsi86 *pdata)
664 {
665 	int val;
666 	struct mipi_dsi_host *host;
667 	struct mipi_dsi_device *dsi;
668 	struct device *dev = pdata->dev;
669 	const struct mipi_dsi_device_info info = { .type = "ti_sn_bridge",
670 						   .channel = 0,
671 						   .node = NULL,
672 	};
673 
674 	host = of_find_mipi_dsi_host_by_node(pdata->host_node);
675 	if (!host)
676 		return -EPROBE_DEFER;
677 
678 	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
679 	if (IS_ERR(dsi))
680 		return PTR_ERR(dsi);
681 
682 	/* TODO: setting to 4 MIPI lanes always for now */
683 	dsi->lanes = 4;
684 	dsi->format = MIPI_DSI_FMT_RGB888;
685 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
686 
687 	/* check if continuous dsi clock is required or not */
688 	pm_runtime_get_sync(dev);
689 	regmap_read(pdata->regmap, SN_DPPLL_SRC_REG, &val);
690 	pm_runtime_put_autosuspend(dev);
691 	if (!(val & DPPLL_CLK_SRC_DSICLK))
692 		dsi->mode_flags |= MIPI_DSI_CLOCK_NON_CONTINUOUS;
693 
694 	pdata->dsi = dsi;
695 
696 	return devm_mipi_dsi_attach(dev, dsi);
697 }
698 
699 static int ti_sn_bridge_attach(struct drm_bridge *bridge,
700 			       enum drm_bridge_attach_flags flags)
701 {
702 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
703 	int ret;
704 
705 	pdata->aux.drm_dev = bridge->dev;
706 	ret = drm_dp_aux_register(&pdata->aux);
707 	if (ret < 0) {
708 		drm_err(bridge->dev, "Failed to register DP AUX channel: %d\n", ret);
709 		return ret;
710 	}
711 
712 	/*
713 	 * Attach the next bridge.
714 	 * We never want the next bridge to *also* create a connector.
715 	 */
716 	ret = drm_bridge_attach(bridge->encoder, pdata->next_bridge,
717 				&pdata->bridge, flags | DRM_BRIDGE_ATTACH_NO_CONNECTOR);
718 	if (ret < 0)
719 		goto err_initted_aux;
720 
721 	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
722 		return 0;
723 
724 	pdata->connector = drm_bridge_connector_init(pdata->bridge.dev,
725 						     pdata->bridge.encoder);
726 	if (IS_ERR(pdata->connector)) {
727 		ret = PTR_ERR(pdata->connector);
728 		goto err_initted_aux;
729 	}
730 
731 	drm_connector_attach_encoder(pdata->connector, pdata->bridge.encoder);
732 
733 	return 0;
734 
735 err_initted_aux:
736 	drm_dp_aux_unregister(&pdata->aux);
737 	return ret;
738 }
739 
740 static void ti_sn_bridge_detach(struct drm_bridge *bridge)
741 {
742 	drm_dp_aux_unregister(&bridge_to_ti_sn65dsi86(bridge)->aux);
743 }
744 
745 static enum drm_mode_status
746 ti_sn_bridge_mode_valid(struct drm_bridge *bridge,
747 			const struct drm_display_info *info,
748 			const struct drm_display_mode *mode)
749 {
750 	/* maximum supported resolution is 4K at 60 fps */
751 	if (mode->clock > 594000)
752 		return MODE_CLOCK_HIGH;
753 
754 	/*
755 	 * The front and back porch registers are 8 bits, and pulse width
756 	 * registers are 15 bits, so reject any modes with larger periods.
757 	 */
758 
759 	if ((mode->hsync_start - mode->hdisplay) > 0xff)
760 		return MODE_HBLANK_WIDE;
761 
762 	if ((mode->vsync_start - mode->vdisplay) > 0xff)
763 		return MODE_VBLANK_WIDE;
764 
765 	if ((mode->hsync_end - mode->hsync_start) > 0x7fff)
766 		return MODE_HSYNC_WIDE;
767 
768 	if ((mode->vsync_end - mode->vsync_start) > 0x7fff)
769 		return MODE_VSYNC_WIDE;
770 
771 	if ((mode->htotal - mode->hsync_end) > 0xff)
772 		return MODE_HBLANK_WIDE;
773 
774 	if ((mode->vtotal - mode->vsync_end) > 0xff)
775 		return MODE_VBLANK_WIDE;
776 
777 	return MODE_OK;
778 }
779 
780 static void ti_sn_bridge_atomic_disable(struct drm_bridge *bridge,
781 					struct drm_bridge_state *old_bridge_state)
782 {
783 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
784 
785 	/* disable video stream */
786 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE, 0);
787 }
788 
789 static void ti_sn_bridge_set_dsi_rate(struct ti_sn65dsi86 *pdata)
790 {
791 	unsigned int bit_rate_mhz, clk_freq_mhz;
792 	unsigned int val;
793 	struct drm_display_mode *mode =
794 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
795 
796 	/* set DSIA clk frequency */
797 	bit_rate_mhz = (mode->clock / 1000) *
798 			mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
799 	clk_freq_mhz = bit_rate_mhz / (pdata->dsi->lanes * 2);
800 
801 	/* for each increment in val, frequency increases by 5MHz */
802 	val = (MIN_DSI_CLK_FREQ_MHZ / 5) +
803 		(((clk_freq_mhz - MIN_DSI_CLK_FREQ_MHZ) / 5) & 0xFF);
804 	regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val);
805 }
806 
807 static unsigned int ti_sn_bridge_get_bpp(struct drm_connector *connector)
808 {
809 	if (connector->display_info.bpc <= 6)
810 		return 18;
811 	else
812 		return 24;
813 }
814 
815 /*
816  * LUT index corresponds to register value and
817  * LUT values corresponds to dp data rate supported
818  * by the bridge in Mbps unit.
819  */
820 static const unsigned int ti_sn_bridge_dp_rate_lut[] = {
821 	0, 1620, 2160, 2430, 2700, 3240, 4320, 5400
822 };
823 
824 static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn65dsi86 *pdata, unsigned int bpp)
825 {
826 	unsigned int bit_rate_khz, dp_rate_mhz;
827 	unsigned int i;
828 	struct drm_display_mode *mode =
829 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
830 
831 	/* Calculate minimum bit rate based on our pixel clock. */
832 	bit_rate_khz = mode->clock * bpp;
833 
834 	/* Calculate minimum DP data rate, taking 80% as per DP spec */
835 	dp_rate_mhz = DIV_ROUND_UP(bit_rate_khz * DP_CLK_FUDGE_NUM,
836 				   1000 * pdata->dp_lanes * DP_CLK_FUDGE_DEN);
837 
838 	for (i = 1; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++)
839 		if (ti_sn_bridge_dp_rate_lut[i] >= dp_rate_mhz)
840 			break;
841 
842 	return i;
843 }
844 
845 static unsigned int ti_sn_bridge_read_valid_rates(struct ti_sn65dsi86 *pdata)
846 {
847 	unsigned int valid_rates = 0;
848 	unsigned int rate_per_200khz;
849 	unsigned int rate_mhz;
850 	u8 dpcd_val;
851 	int ret;
852 	int i, j;
853 
854 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_EDP_DPCD_REV, &dpcd_val);
855 	if (ret != 1) {
856 		DRM_DEV_ERROR(pdata->dev,
857 			      "Can't read eDP rev (%d), assuming 1.1\n", ret);
858 		dpcd_val = DP_EDP_11;
859 	}
860 
861 	if (dpcd_val >= DP_EDP_14) {
862 		/* eDP 1.4 devices must provide a custom table */
863 		__le16 sink_rates[DP_MAX_SUPPORTED_RATES];
864 
865 		ret = drm_dp_dpcd_read(&pdata->aux, DP_SUPPORTED_LINK_RATES,
866 				       sink_rates, sizeof(sink_rates));
867 
868 		if (ret != sizeof(sink_rates)) {
869 			DRM_DEV_ERROR(pdata->dev,
870 				"Can't read supported rate table (%d)\n", ret);
871 
872 			/* By zeroing we'll fall back to DP_MAX_LINK_RATE. */
873 			memset(sink_rates, 0, sizeof(sink_rates));
874 		}
875 
876 		for (i = 0; i < ARRAY_SIZE(sink_rates); i++) {
877 			rate_per_200khz = le16_to_cpu(sink_rates[i]);
878 
879 			if (!rate_per_200khz)
880 				break;
881 
882 			rate_mhz = rate_per_200khz * 200 / 1000;
883 			for (j = 0;
884 			     j < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
885 			     j++) {
886 				if (ti_sn_bridge_dp_rate_lut[j] == rate_mhz)
887 					valid_rates |= BIT(j);
888 			}
889 		}
890 
891 		for (i = 0; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut); i++) {
892 			if (valid_rates & BIT(i))
893 				return valid_rates;
894 		}
895 		DRM_DEV_ERROR(pdata->dev,
896 			      "No matching eDP rates in table; falling back\n");
897 	}
898 
899 	/* On older versions best we can do is use DP_MAX_LINK_RATE */
900 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LINK_RATE, &dpcd_val);
901 	if (ret != 1) {
902 		DRM_DEV_ERROR(pdata->dev,
903 			      "Can't read max rate (%d); assuming 5.4 GHz\n",
904 			      ret);
905 		dpcd_val = DP_LINK_BW_5_4;
906 	}
907 
908 	switch (dpcd_val) {
909 	default:
910 		DRM_DEV_ERROR(pdata->dev,
911 			      "Unexpected max rate (%#x); assuming 5.4 GHz\n",
912 			      (int)dpcd_val);
913 		fallthrough;
914 	case DP_LINK_BW_5_4:
915 		valid_rates |= BIT(7);
916 		fallthrough;
917 	case DP_LINK_BW_2_7:
918 		valid_rates |= BIT(4);
919 		fallthrough;
920 	case DP_LINK_BW_1_62:
921 		valid_rates |= BIT(1);
922 		break;
923 	}
924 
925 	return valid_rates;
926 }
927 
928 static void ti_sn_bridge_set_video_timings(struct ti_sn65dsi86 *pdata)
929 {
930 	struct drm_display_mode *mode =
931 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
932 	u8 hsync_polarity = 0, vsync_polarity = 0;
933 
934 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
935 		hsync_polarity = CHA_HSYNC_POLARITY;
936 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
937 		vsync_polarity = CHA_VSYNC_POLARITY;
938 
939 	ti_sn65dsi86_write_u16(pdata, SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG,
940 			       mode->hdisplay);
941 	ti_sn65dsi86_write_u16(pdata, SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG,
942 			       mode->vdisplay);
943 	regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG,
944 		     (mode->hsync_end - mode->hsync_start) & 0xFF);
945 	regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_HIGH_REG,
946 		     (((mode->hsync_end - mode->hsync_start) >> 8) & 0x7F) |
947 		     hsync_polarity);
948 	regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG,
949 		     (mode->vsync_end - mode->vsync_start) & 0xFF);
950 	regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_HIGH_REG,
951 		     (((mode->vsync_end - mode->vsync_start) >> 8) & 0x7F) |
952 		     vsync_polarity);
953 
954 	regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_BACK_PORCH_REG,
955 		     (mode->htotal - mode->hsync_end) & 0xFF);
956 	regmap_write(pdata->regmap, SN_CHA_VERTICAL_BACK_PORCH_REG,
957 		     (mode->vtotal - mode->vsync_end) & 0xFF);
958 
959 	regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_FRONT_PORCH_REG,
960 		     (mode->hsync_start - mode->hdisplay) & 0xFF);
961 	regmap_write(pdata->regmap, SN_CHA_VERTICAL_FRONT_PORCH_REG,
962 		     (mode->vsync_start - mode->vdisplay) & 0xFF);
963 
964 	usleep_range(10000, 10500); /* 10ms delay recommended by spec */
965 }
966 
967 static unsigned int ti_sn_get_max_lanes(struct ti_sn65dsi86 *pdata)
968 {
969 	u8 data;
970 	int ret;
971 
972 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LANE_COUNT, &data);
973 	if (ret != 1) {
974 		DRM_DEV_ERROR(pdata->dev,
975 			      "Can't read lane count (%d); assuming 4\n", ret);
976 		return 4;
977 	}
978 
979 	return data & DP_LANE_COUNT_MASK;
980 }
981 
982 static int ti_sn_link_training(struct ti_sn65dsi86 *pdata, int dp_rate_idx,
983 			       const char **last_err_str)
984 {
985 	unsigned int val;
986 	int ret;
987 	int i;
988 
989 	/* set dp clk frequency value */
990 	regmap_update_bits(pdata->regmap, SN_DATARATE_CONFIG_REG,
991 			   DP_DATARATE_MASK, DP_DATARATE(dp_rate_idx));
992 
993 	/* enable DP PLL */
994 	regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
995 
996 	ret = regmap_read_poll_timeout(pdata->regmap, SN_DPPLL_SRC_REG, val,
997 				       val & DPPLL_SRC_DP_PLL_LOCK, 1000,
998 				       50 * 1000);
999 	if (ret) {
1000 		*last_err_str = "DP_PLL_LOCK polling failed";
1001 		goto exit;
1002 	}
1003 
1004 	/*
1005 	 * We'll try to link train several times.  As part of link training
1006 	 * the bridge chip will write DP_SET_POWER_D0 to DP_SET_POWER.  If
1007 	 * the panel isn't ready quite it might respond NAK here which means
1008 	 * we need to try again.
1009 	 */
1010 	for (i = 0; i < SN_LINK_TRAINING_TRIES; i++) {
1011 		/* Semi auto link training mode */
1012 		regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A);
1013 		ret = regmap_read_poll_timeout(pdata->regmap, SN_ML_TX_MODE_REG, val,
1014 					       val == ML_TX_MAIN_LINK_OFF ||
1015 					       val == ML_TX_NORMAL_MODE, 1000,
1016 					       500 * 1000);
1017 		if (ret) {
1018 			*last_err_str = "Training complete polling failed";
1019 		} else if (val == ML_TX_MAIN_LINK_OFF) {
1020 			*last_err_str = "Link training failed, link is off";
1021 			ret = -EIO;
1022 			continue;
1023 		}
1024 
1025 		break;
1026 	}
1027 
1028 	/* If we saw quite a few retries, add a note about it */
1029 	if (!ret && i > SN_LINK_TRAINING_TRIES / 2)
1030 		DRM_DEV_INFO(pdata->dev, "Link training needed %d retries\n", i);
1031 
1032 exit:
1033 	/* Disable the PLL if we failed */
1034 	if (ret)
1035 		regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
1036 
1037 	return ret;
1038 }
1039 
1040 static void ti_sn_bridge_atomic_enable(struct drm_bridge *bridge,
1041 				       struct drm_bridge_state *old_bridge_state)
1042 {
1043 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1044 	struct drm_connector *connector;
1045 	const char *last_err_str = "No supported DP rate";
1046 	unsigned int valid_rates;
1047 	int dp_rate_idx;
1048 	unsigned int val;
1049 	int ret = -EINVAL;
1050 	int max_dp_lanes;
1051 	unsigned int bpp;
1052 
1053 	connector = drm_atomic_get_new_connector_for_encoder(old_bridge_state->base.state,
1054 							     bridge->encoder);
1055 	if (!connector) {
1056 		dev_err_ratelimited(pdata->dev, "Could not get the connector\n");
1057 		return;
1058 	}
1059 
1060 	max_dp_lanes = ti_sn_get_max_lanes(pdata);
1061 	pdata->dp_lanes = min(pdata->dp_lanes, max_dp_lanes);
1062 
1063 	/* DSI_A lane config */
1064 	val = CHA_DSI_LANES(SN_MAX_DP_LANES - pdata->dsi->lanes);
1065 	regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG,
1066 			   CHA_DSI_LANES_MASK, val);
1067 
1068 	regmap_write(pdata->regmap, SN_LN_ASSIGN_REG, pdata->ln_assign);
1069 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, LN_POLRS_MASK,
1070 			   pdata->ln_polrs << LN_POLRS_OFFSET);
1071 
1072 	/* set dsi clk frequency value */
1073 	ti_sn_bridge_set_dsi_rate(pdata);
1074 
1075 	/*
1076 	 * The SN65DSI86 only supports ASSR Display Authentication method and
1077 	 * this method is enabled for eDP panels. An eDP panel must support this
1078 	 * authentication method. We need to enable this method in the eDP panel
1079 	 * at DisplayPort address 0x0010A prior to link training.
1080 	 *
1081 	 * As only ASSR is supported by SN65DSI86, for full DisplayPort displays
1082 	 * we need to disable the scrambler.
1083 	 */
1084 	if (pdata->bridge.type == DRM_MODE_CONNECTOR_eDP) {
1085 		drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET,
1086 				   DP_ALTERNATE_SCRAMBLER_RESET_ENABLE);
1087 
1088 		regmap_update_bits(pdata->regmap, SN_TRAINING_SETTING_REG,
1089 				   SCRAMBLE_DISABLE, 0);
1090 	} else {
1091 		regmap_update_bits(pdata->regmap, SN_TRAINING_SETTING_REG,
1092 				   SCRAMBLE_DISABLE, SCRAMBLE_DISABLE);
1093 	}
1094 
1095 	bpp = ti_sn_bridge_get_bpp(connector);
1096 	/* Set the DP output format (18 bpp or 24 bpp) */
1097 	val = bpp == 18 ? BPP_18_RGB : 0;
1098 	regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val);
1099 
1100 	/* DP lane config */
1101 	val = DP_NUM_LANES(min(pdata->dp_lanes, 3));
1102 	regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK,
1103 			   val);
1104 
1105 	valid_rates = ti_sn_bridge_read_valid_rates(pdata);
1106 
1107 	/* Train until we run out of rates */
1108 	for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata, bpp);
1109 	     dp_rate_idx < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
1110 	     dp_rate_idx++) {
1111 		if (!(valid_rates & BIT(dp_rate_idx)))
1112 			continue;
1113 
1114 		ret = ti_sn_link_training(pdata, dp_rate_idx, &last_err_str);
1115 		if (!ret)
1116 			break;
1117 	}
1118 	if (ret) {
1119 		DRM_DEV_ERROR(pdata->dev, "%s (%d)\n", last_err_str, ret);
1120 		return;
1121 	}
1122 
1123 	/* config video parameters */
1124 	ti_sn_bridge_set_video_timings(pdata);
1125 
1126 	/* enable video stream */
1127 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE,
1128 			   VSTREAM_ENABLE);
1129 }
1130 
1131 static void ti_sn_bridge_atomic_pre_enable(struct drm_bridge *bridge,
1132 					   struct drm_bridge_state *old_bridge_state)
1133 {
1134 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1135 
1136 	pm_runtime_get_sync(pdata->dev);
1137 
1138 	if (!pdata->refclk)
1139 		ti_sn65dsi86_enable_comms(pdata);
1140 
1141 	/* td7: min 100 us after enable before DSI data */
1142 	usleep_range(100, 110);
1143 }
1144 
1145 static void ti_sn_bridge_atomic_post_disable(struct drm_bridge *bridge,
1146 					     struct drm_bridge_state *old_bridge_state)
1147 {
1148 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1149 
1150 	/* semi auto link training mode OFF */
1151 	regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0);
1152 	/* Num lanes to 0 as per power sequencing in data sheet */
1153 	regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, 0);
1154 	/* disable DP PLL */
1155 	regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
1156 
1157 	if (!pdata->refclk)
1158 		ti_sn65dsi86_disable_comms(pdata);
1159 
1160 	pm_runtime_put_sync(pdata->dev);
1161 }
1162 
1163 static enum drm_connector_status ti_sn_bridge_detect(struct drm_bridge *bridge)
1164 {
1165 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1166 	int val = 0;
1167 
1168 	pm_runtime_get_sync(pdata->dev);
1169 	regmap_read(pdata->regmap, SN_HPD_DISABLE_REG, &val);
1170 	pm_runtime_put_autosuspend(pdata->dev);
1171 
1172 	return val & HPD_DEBOUNCED_STATE ? connector_status_connected
1173 					 : connector_status_disconnected;
1174 }
1175 
1176 static struct edid *ti_sn_bridge_get_edid(struct drm_bridge *bridge,
1177 					  struct drm_connector *connector)
1178 {
1179 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1180 
1181 	return drm_get_edid(connector, &pdata->aux.ddc);
1182 }
1183 
1184 static const struct drm_bridge_funcs ti_sn_bridge_funcs = {
1185 	.attach = ti_sn_bridge_attach,
1186 	.detach = ti_sn_bridge_detach,
1187 	.mode_valid = ti_sn_bridge_mode_valid,
1188 	.get_edid = ti_sn_bridge_get_edid,
1189 	.detect = ti_sn_bridge_detect,
1190 	.atomic_pre_enable = ti_sn_bridge_atomic_pre_enable,
1191 	.atomic_enable = ti_sn_bridge_atomic_enable,
1192 	.atomic_disable = ti_sn_bridge_atomic_disable,
1193 	.atomic_post_disable = ti_sn_bridge_atomic_post_disable,
1194 	.atomic_reset = drm_atomic_helper_bridge_reset,
1195 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
1196 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
1197 };
1198 
1199 static void ti_sn_bridge_parse_lanes(struct ti_sn65dsi86 *pdata,
1200 				     struct device_node *np)
1201 {
1202 	u32 lane_assignments[SN_MAX_DP_LANES] = { 0, 1, 2, 3 };
1203 	u32 lane_polarities[SN_MAX_DP_LANES] = { };
1204 	struct device_node *endpoint;
1205 	u8 ln_assign = 0;
1206 	u8 ln_polrs = 0;
1207 	int dp_lanes;
1208 	int i;
1209 
1210 	/*
1211 	 * Read config from the device tree about lane remapping and lane
1212 	 * polarities.  These are optional and we assume identity map and
1213 	 * normal polarity if nothing is specified.  It's OK to specify just
1214 	 * data-lanes but not lane-polarities but not vice versa.
1215 	 *
1216 	 * Error checking is light (we just make sure we don't crash or
1217 	 * buffer overrun) and we assume dts is well formed and specifying
1218 	 * mappings that the hardware supports.
1219 	 */
1220 	endpoint = of_graph_get_endpoint_by_regs(np, 1, -1);
1221 	dp_lanes = drm_of_get_data_lanes_count(endpoint, 1, SN_MAX_DP_LANES);
1222 	if (dp_lanes > 0) {
1223 		of_property_read_u32_array(endpoint, "data-lanes",
1224 					   lane_assignments, dp_lanes);
1225 		of_property_read_u32_array(endpoint, "lane-polarities",
1226 					   lane_polarities, dp_lanes);
1227 	} else {
1228 		dp_lanes = SN_MAX_DP_LANES;
1229 	}
1230 	of_node_put(endpoint);
1231 
1232 	/*
1233 	 * Convert into register format.  Loop over all lanes even if
1234 	 * data-lanes had fewer elements so that we nicely initialize
1235 	 * the LN_ASSIGN register.
1236 	 */
1237 	for (i = SN_MAX_DP_LANES - 1; i >= 0; i--) {
1238 		ln_assign = ln_assign << LN_ASSIGN_WIDTH | lane_assignments[i];
1239 		ln_polrs = ln_polrs << 1 | lane_polarities[i];
1240 	}
1241 
1242 	/* Stash in our struct for when we power on */
1243 	pdata->dp_lanes = dp_lanes;
1244 	pdata->ln_assign = ln_assign;
1245 	pdata->ln_polrs = ln_polrs;
1246 }
1247 
1248 static int ti_sn_bridge_parse_dsi_host(struct ti_sn65dsi86 *pdata)
1249 {
1250 	struct device_node *np = pdata->dev->of_node;
1251 
1252 	pdata->host_node = of_graph_get_remote_node(np, 0, 0);
1253 
1254 	if (!pdata->host_node) {
1255 		DRM_ERROR("remote dsi host node not found\n");
1256 		return -ENODEV;
1257 	}
1258 
1259 	return 0;
1260 }
1261 
1262 static int ti_sn_bridge_probe(struct auxiliary_device *adev,
1263 			      const struct auxiliary_device_id *id)
1264 {
1265 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1266 	struct device_node *np = pdata->dev->of_node;
1267 	int ret;
1268 
1269 	pdata->next_bridge = devm_drm_of_get_bridge(pdata->dev, np, 1, 0);
1270 	if (IS_ERR(pdata->next_bridge))
1271 		return dev_err_probe(pdata->dev, PTR_ERR(pdata->next_bridge),
1272 				     "failed to create panel bridge\n");
1273 
1274 	ti_sn_bridge_parse_lanes(pdata, np);
1275 
1276 	ret = ti_sn_bridge_parse_dsi_host(pdata);
1277 	if (ret)
1278 		return ret;
1279 
1280 	pdata->bridge.funcs = &ti_sn_bridge_funcs;
1281 	pdata->bridge.of_node = np;
1282 	pdata->bridge.type = pdata->next_bridge->type == DRM_MODE_CONNECTOR_DisplayPort
1283 			   ? DRM_MODE_CONNECTOR_DisplayPort : DRM_MODE_CONNECTOR_eDP;
1284 
1285 	if (pdata->bridge.type == DRM_MODE_CONNECTOR_DisplayPort)
1286 		pdata->bridge.ops = DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_DETECT;
1287 
1288 	drm_bridge_add(&pdata->bridge);
1289 
1290 	ret = ti_sn_attach_host(pdata);
1291 	if (ret) {
1292 		dev_err_probe(pdata->dev, ret, "failed to attach dsi host\n");
1293 		goto err_remove_bridge;
1294 	}
1295 
1296 	return 0;
1297 
1298 err_remove_bridge:
1299 	drm_bridge_remove(&pdata->bridge);
1300 	return ret;
1301 }
1302 
1303 static void ti_sn_bridge_remove(struct auxiliary_device *adev)
1304 {
1305 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1306 
1307 	if (!pdata)
1308 		return;
1309 
1310 	drm_bridge_remove(&pdata->bridge);
1311 
1312 	of_node_put(pdata->host_node);
1313 }
1314 
1315 static const struct auxiliary_device_id ti_sn_bridge_id_table[] = {
1316 	{ .name = "ti_sn65dsi86.bridge", },
1317 	{},
1318 };
1319 
1320 static struct auxiliary_driver ti_sn_bridge_driver = {
1321 	.name = "bridge",
1322 	.probe = ti_sn_bridge_probe,
1323 	.remove = ti_sn_bridge_remove,
1324 	.id_table = ti_sn_bridge_id_table,
1325 };
1326 
1327 /* -----------------------------------------------------------------------------
1328  * PWM Controller
1329  */
1330 #if defined(CONFIG_PWM)
1331 static int ti_sn_pwm_pin_request(struct ti_sn65dsi86 *pdata)
1332 {
1333 	return atomic_xchg(&pdata->pwm_pin_busy, 1) ? -EBUSY : 0;
1334 }
1335 
1336 static void ti_sn_pwm_pin_release(struct ti_sn65dsi86 *pdata)
1337 {
1338 	atomic_set(&pdata->pwm_pin_busy, 0);
1339 }
1340 
1341 static struct ti_sn65dsi86 *pwm_chip_to_ti_sn_bridge(struct pwm_chip *chip)
1342 {
1343 	return container_of(chip, struct ti_sn65dsi86, pchip);
1344 }
1345 
1346 static int ti_sn_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
1347 {
1348 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1349 
1350 	return ti_sn_pwm_pin_request(pdata);
1351 }
1352 
1353 static void ti_sn_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
1354 {
1355 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1356 
1357 	ti_sn_pwm_pin_release(pdata);
1358 }
1359 
1360 /*
1361  * Limitations:
1362  * - The PWM signal is not driven when the chip is powered down, or in its
1363  *   reset state and the driver does not implement the "suspend state"
1364  *   described in the documentation. In order to save power, state->enabled is
1365  *   interpreted as denoting if the signal is expected to be valid, and is used
1366  *   to determine if the chip needs to be kept powered.
1367  * - Changing both period and duty_cycle is not done atomically, neither is the
1368  *   multi-byte register updates, so the output might briefly be undefined
1369  *   during update.
1370  */
1371 static int ti_sn_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
1372 			   const struct pwm_state *state)
1373 {
1374 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1375 	unsigned int pwm_en_inv;
1376 	unsigned int backlight;
1377 	unsigned int pre_div;
1378 	unsigned int scale;
1379 	u64 period_max;
1380 	u64 period;
1381 	int ret;
1382 
1383 	if (!pdata->pwm_enabled) {
1384 		ret = pm_runtime_get_sync(pdata->dev);
1385 		if (ret < 0) {
1386 			pm_runtime_put_sync(pdata->dev);
1387 			return ret;
1388 		}
1389 	}
1390 
1391 	if (state->enabled) {
1392 		if (!pdata->pwm_enabled) {
1393 			/*
1394 			 * The chip might have been powered down while we
1395 			 * didn't hold a PM runtime reference, so mux in the
1396 			 * PWM function on the GPIO pin again.
1397 			 */
1398 			ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1399 						 SN_GPIO_MUX_MASK << (2 * SN_PWM_GPIO_IDX),
1400 						 SN_GPIO_MUX_SPECIAL << (2 * SN_PWM_GPIO_IDX));
1401 			if (ret) {
1402 				dev_err(pdata->dev, "failed to mux in PWM function\n");
1403 				goto out;
1404 			}
1405 		}
1406 
1407 		/*
1408 		 * Per the datasheet the PWM frequency is given by:
1409 		 *
1410 		 *                          REFCLK_FREQ
1411 		 *   PWM_FREQ = -----------------------------------
1412 		 *               PWM_PRE_DIV * BACKLIGHT_SCALE + 1
1413 		 *
1414 		 * However, after careful review the author is convinced that
1415 		 * the documentation has lost some parenthesis around
1416 		 * "BACKLIGHT_SCALE + 1".
1417 		 *
1418 		 * With the period T_pwm = 1/PWM_FREQ this can be written:
1419 		 *
1420 		 *   T_pwm * REFCLK_FREQ = PWM_PRE_DIV * (BACKLIGHT_SCALE + 1)
1421 		 *
1422 		 * In order to keep BACKLIGHT_SCALE within its 16 bits,
1423 		 * PWM_PRE_DIV must be:
1424 		 *
1425 		 *                     T_pwm * REFCLK_FREQ
1426 		 *   PWM_PRE_DIV >= -------------------------
1427 		 *                   BACKLIGHT_SCALE_MAX + 1
1428 		 *
1429 		 * To simplify the search and to favour higher resolution of
1430 		 * the duty cycle over accuracy of the period, the lowest
1431 		 * possible PWM_PRE_DIV is used. Finally the scale is
1432 		 * calculated as:
1433 		 *
1434 		 *                      T_pwm * REFCLK_FREQ
1435 		 *   BACKLIGHT_SCALE = ---------------------- - 1
1436 		 *                          PWM_PRE_DIV
1437 		 *
1438 		 * Here T_pwm is represented in seconds, so appropriate scaling
1439 		 * to nanoseconds is necessary.
1440 		 */
1441 
1442 		/* Minimum T_pwm is 1 / REFCLK_FREQ */
1443 		if (state->period <= NSEC_PER_SEC / pdata->pwm_refclk_freq) {
1444 			ret = -EINVAL;
1445 			goto out;
1446 		}
1447 
1448 		/*
1449 		 * Maximum T_pwm is 255 * (65535 + 1) / REFCLK_FREQ
1450 		 * Limit period to this to avoid overflows
1451 		 */
1452 		period_max = div_u64((u64)NSEC_PER_SEC * 255 * (65535 + 1),
1453 				     pdata->pwm_refclk_freq);
1454 		period = min(state->period, period_max);
1455 
1456 		pre_div = DIV64_U64_ROUND_UP(period * pdata->pwm_refclk_freq,
1457 					     (u64)NSEC_PER_SEC * (BACKLIGHT_SCALE_MAX + 1));
1458 		scale = div64_u64(period * pdata->pwm_refclk_freq, (u64)NSEC_PER_SEC * pre_div) - 1;
1459 
1460 		/*
1461 		 * The documentation has the duty ratio given as:
1462 		 *
1463 		 *     duty          BACKLIGHT
1464 		 *   ------- = ---------------------
1465 		 *    period    BACKLIGHT_SCALE + 1
1466 		 *
1467 		 * Solve for BACKLIGHT, substituting BACKLIGHT_SCALE according
1468 		 * to definition above and adjusting for nanosecond
1469 		 * representation of duty cycle gives us:
1470 		 */
1471 		backlight = div64_u64(state->duty_cycle * pdata->pwm_refclk_freq,
1472 				      (u64)NSEC_PER_SEC * pre_div);
1473 		if (backlight > scale)
1474 			backlight = scale;
1475 
1476 		ret = regmap_write(pdata->regmap, SN_PWM_PRE_DIV_REG, pre_div);
1477 		if (ret) {
1478 			dev_err(pdata->dev, "failed to update PWM_PRE_DIV\n");
1479 			goto out;
1480 		}
1481 
1482 		ti_sn65dsi86_write_u16(pdata, SN_BACKLIGHT_SCALE_REG, scale);
1483 		ti_sn65dsi86_write_u16(pdata, SN_BACKLIGHT_REG, backlight);
1484 	}
1485 
1486 	pwm_en_inv = FIELD_PREP(SN_PWM_EN_MASK, state->enabled) |
1487 		     FIELD_PREP(SN_PWM_INV_MASK, state->polarity == PWM_POLARITY_INVERSED);
1488 	ret = regmap_write(pdata->regmap, SN_PWM_EN_INV_REG, pwm_en_inv);
1489 	if (ret) {
1490 		dev_err(pdata->dev, "failed to update PWM_EN/PWM_INV\n");
1491 		goto out;
1492 	}
1493 
1494 	pdata->pwm_enabled = state->enabled;
1495 out:
1496 
1497 	if (!pdata->pwm_enabled)
1498 		pm_runtime_put_sync(pdata->dev);
1499 
1500 	return ret;
1501 }
1502 
1503 static int ti_sn_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
1504 			       struct pwm_state *state)
1505 {
1506 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1507 	unsigned int pwm_en_inv;
1508 	unsigned int pre_div;
1509 	u16 backlight;
1510 	u16 scale;
1511 	int ret;
1512 
1513 	ret = regmap_read(pdata->regmap, SN_PWM_EN_INV_REG, &pwm_en_inv);
1514 	if (ret)
1515 		return ret;
1516 
1517 	ret = ti_sn65dsi86_read_u16(pdata, SN_BACKLIGHT_SCALE_REG, &scale);
1518 	if (ret)
1519 		return ret;
1520 
1521 	ret = ti_sn65dsi86_read_u16(pdata, SN_BACKLIGHT_REG, &backlight);
1522 	if (ret)
1523 		return ret;
1524 
1525 	ret = regmap_read(pdata->regmap, SN_PWM_PRE_DIV_REG, &pre_div);
1526 	if (ret)
1527 		return ret;
1528 
1529 	state->enabled = FIELD_GET(SN_PWM_EN_MASK, pwm_en_inv);
1530 	if (FIELD_GET(SN_PWM_INV_MASK, pwm_en_inv))
1531 		state->polarity = PWM_POLARITY_INVERSED;
1532 	else
1533 		state->polarity = PWM_POLARITY_NORMAL;
1534 
1535 	state->period = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * pre_div * (scale + 1),
1536 					 pdata->pwm_refclk_freq);
1537 	state->duty_cycle = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * pre_div * backlight,
1538 					     pdata->pwm_refclk_freq);
1539 
1540 	if (state->duty_cycle > state->period)
1541 		state->duty_cycle = state->period;
1542 
1543 	return 0;
1544 }
1545 
1546 static const struct pwm_ops ti_sn_pwm_ops = {
1547 	.request = ti_sn_pwm_request,
1548 	.free = ti_sn_pwm_free,
1549 	.apply = ti_sn_pwm_apply,
1550 	.get_state = ti_sn_pwm_get_state,
1551 	.owner = THIS_MODULE,
1552 };
1553 
1554 static int ti_sn_pwm_probe(struct auxiliary_device *adev,
1555 			   const struct auxiliary_device_id *id)
1556 {
1557 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1558 
1559 	pdata->pchip.dev = pdata->dev;
1560 	pdata->pchip.ops = &ti_sn_pwm_ops;
1561 	pdata->pchip.npwm = 1;
1562 	pdata->pchip.of_xlate = of_pwm_single_xlate;
1563 	pdata->pchip.of_pwm_n_cells = 1;
1564 
1565 	return pwmchip_add(&pdata->pchip);
1566 }
1567 
1568 static void ti_sn_pwm_remove(struct auxiliary_device *adev)
1569 {
1570 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1571 
1572 	pwmchip_remove(&pdata->pchip);
1573 
1574 	if (pdata->pwm_enabled)
1575 		pm_runtime_put_sync(pdata->dev);
1576 }
1577 
1578 static const struct auxiliary_device_id ti_sn_pwm_id_table[] = {
1579 	{ .name = "ti_sn65dsi86.pwm", },
1580 	{},
1581 };
1582 
1583 static struct auxiliary_driver ti_sn_pwm_driver = {
1584 	.name = "pwm",
1585 	.probe = ti_sn_pwm_probe,
1586 	.remove = ti_sn_pwm_remove,
1587 	.id_table = ti_sn_pwm_id_table,
1588 };
1589 
1590 static int __init ti_sn_pwm_register(void)
1591 {
1592 	return auxiliary_driver_register(&ti_sn_pwm_driver);
1593 }
1594 
1595 static void ti_sn_pwm_unregister(void)
1596 {
1597 	auxiliary_driver_unregister(&ti_sn_pwm_driver);
1598 }
1599 
1600 #else
1601 static inline int ti_sn_pwm_pin_request(struct ti_sn65dsi86 *pdata) { return 0; }
1602 static inline void ti_sn_pwm_pin_release(struct ti_sn65dsi86 *pdata) {}
1603 
1604 static inline int ti_sn_pwm_register(void) { return 0; }
1605 static inline void ti_sn_pwm_unregister(void) {}
1606 #endif
1607 
1608 /* -----------------------------------------------------------------------------
1609  * GPIO Controller
1610  */
1611 #if defined(CONFIG_OF_GPIO)
1612 
1613 static int tn_sn_bridge_of_xlate(struct gpio_chip *chip,
1614 				 const struct of_phandle_args *gpiospec,
1615 				 u32 *flags)
1616 {
1617 	if (WARN_ON(gpiospec->args_count < chip->of_gpio_n_cells))
1618 		return -EINVAL;
1619 
1620 	if (gpiospec->args[0] > chip->ngpio || gpiospec->args[0] < 1)
1621 		return -EINVAL;
1622 
1623 	if (flags)
1624 		*flags = gpiospec->args[1];
1625 
1626 	return gpiospec->args[0] - SN_GPIO_PHYSICAL_OFFSET;
1627 }
1628 
1629 static int ti_sn_bridge_gpio_get_direction(struct gpio_chip *chip,
1630 					   unsigned int offset)
1631 {
1632 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1633 
1634 	/*
1635 	 * We already have to keep track of the direction because we use
1636 	 * that to figure out whether we've powered the device.  We can
1637 	 * just return that rather than (maybe) powering up the device
1638 	 * to ask its direction.
1639 	 */
1640 	return test_bit(offset, pdata->gchip_output) ?
1641 		GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
1642 }
1643 
1644 static int ti_sn_bridge_gpio_get(struct gpio_chip *chip, unsigned int offset)
1645 {
1646 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1647 	unsigned int val;
1648 	int ret;
1649 
1650 	/*
1651 	 * When the pin is an input we don't forcibly keep the bridge
1652 	 * powered--we just power it on to read the pin.  NOTE: part of
1653 	 * the reason this works is that the bridge defaults (when
1654 	 * powered back on) to all 4 GPIOs being configured as GPIO input.
1655 	 * Also note that if something else is keeping the chip powered the
1656 	 * pm_runtime functions are lightweight increments of a refcount.
1657 	 */
1658 	pm_runtime_get_sync(pdata->dev);
1659 	ret = regmap_read(pdata->regmap, SN_GPIO_IO_REG, &val);
1660 	pm_runtime_put_autosuspend(pdata->dev);
1661 
1662 	if (ret)
1663 		return ret;
1664 
1665 	return !!(val & BIT(SN_GPIO_INPUT_SHIFT + offset));
1666 }
1667 
1668 static void ti_sn_bridge_gpio_set(struct gpio_chip *chip, unsigned int offset,
1669 				  int val)
1670 {
1671 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1672 	int ret;
1673 
1674 	if (!test_bit(offset, pdata->gchip_output)) {
1675 		dev_err(pdata->dev, "Ignoring GPIO set while input\n");
1676 		return;
1677 	}
1678 
1679 	val &= 1;
1680 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_IO_REG,
1681 				 BIT(SN_GPIO_OUTPUT_SHIFT + offset),
1682 				 val << (SN_GPIO_OUTPUT_SHIFT + offset));
1683 	if (ret)
1684 		dev_warn(pdata->dev,
1685 			 "Failed to set bridge GPIO %u: %d\n", offset, ret);
1686 }
1687 
1688 static int ti_sn_bridge_gpio_direction_input(struct gpio_chip *chip,
1689 					     unsigned int offset)
1690 {
1691 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1692 	int shift = offset * 2;
1693 	int ret;
1694 
1695 	if (!test_and_clear_bit(offset, pdata->gchip_output))
1696 		return 0;
1697 
1698 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1699 				 SN_GPIO_MUX_MASK << shift,
1700 				 SN_GPIO_MUX_INPUT << shift);
1701 	if (ret) {
1702 		set_bit(offset, pdata->gchip_output);
1703 		return ret;
1704 	}
1705 
1706 	/*
1707 	 * NOTE: if nobody else is powering the device this may fully power
1708 	 * it off and when it comes back it will have lost all state, but
1709 	 * that's OK because the default is input and we're now an input.
1710 	 */
1711 	pm_runtime_put_autosuspend(pdata->dev);
1712 
1713 	return 0;
1714 }
1715 
1716 static int ti_sn_bridge_gpio_direction_output(struct gpio_chip *chip,
1717 					      unsigned int offset, int val)
1718 {
1719 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1720 	int shift = offset * 2;
1721 	int ret;
1722 
1723 	if (test_and_set_bit(offset, pdata->gchip_output))
1724 		return 0;
1725 
1726 	pm_runtime_get_sync(pdata->dev);
1727 
1728 	/* Set value first to avoid glitching */
1729 	ti_sn_bridge_gpio_set(chip, offset, val);
1730 
1731 	/* Set direction */
1732 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1733 				 SN_GPIO_MUX_MASK << shift,
1734 				 SN_GPIO_MUX_OUTPUT << shift);
1735 	if (ret) {
1736 		clear_bit(offset, pdata->gchip_output);
1737 		pm_runtime_put_autosuspend(pdata->dev);
1738 	}
1739 
1740 	return ret;
1741 }
1742 
1743 static int ti_sn_bridge_gpio_request(struct gpio_chip *chip, unsigned int offset)
1744 {
1745 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1746 
1747 	if (offset == SN_PWM_GPIO_IDX)
1748 		return ti_sn_pwm_pin_request(pdata);
1749 
1750 	return 0;
1751 }
1752 
1753 static void ti_sn_bridge_gpio_free(struct gpio_chip *chip, unsigned int offset)
1754 {
1755 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1756 
1757 	/* We won't keep pm_runtime if we're input, so switch there on free */
1758 	ti_sn_bridge_gpio_direction_input(chip, offset);
1759 
1760 	if (offset == SN_PWM_GPIO_IDX)
1761 		ti_sn_pwm_pin_release(pdata);
1762 }
1763 
1764 static const char * const ti_sn_bridge_gpio_names[SN_NUM_GPIOS] = {
1765 	"GPIO1", "GPIO2", "GPIO3", "GPIO4"
1766 };
1767 
1768 static int ti_sn_gpio_probe(struct auxiliary_device *adev,
1769 			    const struct auxiliary_device_id *id)
1770 {
1771 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1772 	int ret;
1773 
1774 	/* Only init if someone is going to use us as a GPIO controller */
1775 	if (!of_property_read_bool(pdata->dev->of_node, "gpio-controller"))
1776 		return 0;
1777 
1778 	pdata->gchip.label = dev_name(pdata->dev);
1779 	pdata->gchip.parent = pdata->dev;
1780 	pdata->gchip.owner = THIS_MODULE;
1781 	pdata->gchip.of_xlate = tn_sn_bridge_of_xlate;
1782 	pdata->gchip.of_gpio_n_cells = 2;
1783 	pdata->gchip.request = ti_sn_bridge_gpio_request;
1784 	pdata->gchip.free = ti_sn_bridge_gpio_free;
1785 	pdata->gchip.get_direction = ti_sn_bridge_gpio_get_direction;
1786 	pdata->gchip.direction_input = ti_sn_bridge_gpio_direction_input;
1787 	pdata->gchip.direction_output = ti_sn_bridge_gpio_direction_output;
1788 	pdata->gchip.get = ti_sn_bridge_gpio_get;
1789 	pdata->gchip.set = ti_sn_bridge_gpio_set;
1790 	pdata->gchip.can_sleep = true;
1791 	pdata->gchip.names = ti_sn_bridge_gpio_names;
1792 	pdata->gchip.ngpio = SN_NUM_GPIOS;
1793 	pdata->gchip.base = -1;
1794 	ret = devm_gpiochip_add_data(&adev->dev, &pdata->gchip, pdata);
1795 	if (ret)
1796 		dev_err(pdata->dev, "can't add gpio chip\n");
1797 
1798 	return ret;
1799 }
1800 
1801 static const struct auxiliary_device_id ti_sn_gpio_id_table[] = {
1802 	{ .name = "ti_sn65dsi86.gpio", },
1803 	{},
1804 };
1805 
1806 MODULE_DEVICE_TABLE(auxiliary, ti_sn_gpio_id_table);
1807 
1808 static struct auxiliary_driver ti_sn_gpio_driver = {
1809 	.name = "gpio",
1810 	.probe = ti_sn_gpio_probe,
1811 	.id_table = ti_sn_gpio_id_table,
1812 };
1813 
1814 static int __init ti_sn_gpio_register(void)
1815 {
1816 	return auxiliary_driver_register(&ti_sn_gpio_driver);
1817 }
1818 
1819 static void ti_sn_gpio_unregister(void)
1820 {
1821 	auxiliary_driver_unregister(&ti_sn_gpio_driver);
1822 }
1823 
1824 #else
1825 
1826 static inline int ti_sn_gpio_register(void) { return 0; }
1827 static inline void ti_sn_gpio_unregister(void) {}
1828 
1829 #endif
1830 
1831 /* -----------------------------------------------------------------------------
1832  * Probe & Remove
1833  */
1834 
1835 static void ti_sn65dsi86_runtime_disable(void *data)
1836 {
1837 	pm_runtime_dont_use_autosuspend(data);
1838 	pm_runtime_disable(data);
1839 }
1840 
1841 static int ti_sn65dsi86_parse_regulators(struct ti_sn65dsi86 *pdata)
1842 {
1843 	unsigned int i;
1844 	const char * const ti_sn_bridge_supply_names[] = {
1845 		"vcca", "vcc", "vccio", "vpll",
1846 	};
1847 
1848 	for (i = 0; i < SN_REGULATOR_SUPPLY_NUM; i++)
1849 		pdata->supplies[i].supply = ti_sn_bridge_supply_names[i];
1850 
1851 	return devm_regulator_bulk_get(pdata->dev, SN_REGULATOR_SUPPLY_NUM,
1852 				       pdata->supplies);
1853 }
1854 
1855 static int ti_sn65dsi86_probe(struct i2c_client *client,
1856 			      const struct i2c_device_id *id)
1857 {
1858 	struct device *dev = &client->dev;
1859 	struct ti_sn65dsi86 *pdata;
1860 	int ret;
1861 
1862 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1863 		DRM_ERROR("device doesn't support I2C\n");
1864 		return -ENODEV;
1865 	}
1866 
1867 	pdata = devm_kzalloc(dev, sizeof(struct ti_sn65dsi86), GFP_KERNEL);
1868 	if (!pdata)
1869 		return -ENOMEM;
1870 	dev_set_drvdata(dev, pdata);
1871 	pdata->dev = dev;
1872 
1873 	mutex_init(&pdata->comms_mutex);
1874 
1875 	pdata->regmap = devm_regmap_init_i2c(client,
1876 					     &ti_sn65dsi86_regmap_config);
1877 	if (IS_ERR(pdata->regmap))
1878 		return dev_err_probe(dev, PTR_ERR(pdata->regmap),
1879 				     "regmap i2c init failed\n");
1880 
1881 	pdata->enable_gpio = devm_gpiod_get_optional(dev, "enable",
1882 						     GPIOD_OUT_LOW);
1883 	if (IS_ERR(pdata->enable_gpio))
1884 		return dev_err_probe(dev, PTR_ERR(pdata->enable_gpio),
1885 				     "failed to get enable gpio from DT\n");
1886 
1887 	ret = ti_sn65dsi86_parse_regulators(pdata);
1888 	if (ret)
1889 		return dev_err_probe(dev, ret, "failed to parse regulators\n");
1890 
1891 	pdata->refclk = devm_clk_get_optional(dev, "refclk");
1892 	if (IS_ERR(pdata->refclk))
1893 		return dev_err_probe(dev, PTR_ERR(pdata->refclk),
1894 				     "failed to get reference clock\n");
1895 
1896 	pm_runtime_enable(dev);
1897 	pm_runtime_set_autosuspend_delay(pdata->dev, 500);
1898 	pm_runtime_use_autosuspend(pdata->dev);
1899 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_runtime_disable, dev);
1900 	if (ret)
1901 		return ret;
1902 
1903 	ti_sn65dsi86_debugfs_init(pdata);
1904 
1905 	/*
1906 	 * Break ourselves up into a collection of aux devices. The only real
1907 	 * motiviation here is to solve the chicken-and-egg problem of probe
1908 	 * ordering. The bridge wants the panel to be there when it probes.
1909 	 * The panel wants its HPD GPIO (provided by sn65dsi86 on some boards)
1910 	 * when it probes. The panel and maybe backlight might want the DDC
1911 	 * bus or the pwm_chip. Having sub-devices allows the some sub devices
1912 	 * to finish probing even if others return -EPROBE_DEFER and gets us
1913 	 * around the problems.
1914 	 */
1915 
1916 	if (IS_ENABLED(CONFIG_OF_GPIO)) {
1917 		ret = ti_sn65dsi86_add_aux_device(pdata, &pdata->gpio_aux, "gpio");
1918 		if (ret)
1919 			return ret;
1920 	}
1921 
1922 	if (IS_ENABLED(CONFIG_PWM)) {
1923 		ret = ti_sn65dsi86_add_aux_device(pdata, &pdata->pwm_aux, "pwm");
1924 		if (ret)
1925 			return ret;
1926 	}
1927 
1928 	/*
1929 	 * NOTE: At the end of the AUX channel probe we'll add the aux device
1930 	 * for the bridge. This is because the bridge can't be used until the
1931 	 * AUX channel is there and this is a very simple solution to the
1932 	 * dependency problem.
1933 	 */
1934 	return ti_sn65dsi86_add_aux_device(pdata, &pdata->aux_aux, "aux");
1935 }
1936 
1937 static struct i2c_device_id ti_sn65dsi86_id[] = {
1938 	{ "ti,sn65dsi86", 0},
1939 	{},
1940 };
1941 MODULE_DEVICE_TABLE(i2c, ti_sn65dsi86_id);
1942 
1943 static const struct of_device_id ti_sn65dsi86_match_table[] = {
1944 	{.compatible = "ti,sn65dsi86"},
1945 	{},
1946 };
1947 MODULE_DEVICE_TABLE(of, ti_sn65dsi86_match_table);
1948 
1949 static struct i2c_driver ti_sn65dsi86_driver = {
1950 	.driver = {
1951 		.name = "ti_sn65dsi86",
1952 		.of_match_table = ti_sn65dsi86_match_table,
1953 		.pm = &ti_sn65dsi86_pm_ops,
1954 	},
1955 	.probe = ti_sn65dsi86_probe,
1956 	.id_table = ti_sn65dsi86_id,
1957 };
1958 
1959 static int __init ti_sn65dsi86_init(void)
1960 {
1961 	int ret;
1962 
1963 	ret = i2c_add_driver(&ti_sn65dsi86_driver);
1964 	if (ret)
1965 		return ret;
1966 
1967 	ret = ti_sn_gpio_register();
1968 	if (ret)
1969 		goto err_main_was_registered;
1970 
1971 	ret = ti_sn_pwm_register();
1972 	if (ret)
1973 		goto err_gpio_was_registered;
1974 
1975 	ret = auxiliary_driver_register(&ti_sn_aux_driver);
1976 	if (ret)
1977 		goto err_pwm_was_registered;
1978 
1979 	ret = auxiliary_driver_register(&ti_sn_bridge_driver);
1980 	if (ret)
1981 		goto err_aux_was_registered;
1982 
1983 	return 0;
1984 
1985 err_aux_was_registered:
1986 	auxiliary_driver_unregister(&ti_sn_aux_driver);
1987 err_pwm_was_registered:
1988 	ti_sn_pwm_unregister();
1989 err_gpio_was_registered:
1990 	ti_sn_gpio_unregister();
1991 err_main_was_registered:
1992 	i2c_del_driver(&ti_sn65dsi86_driver);
1993 
1994 	return ret;
1995 }
1996 module_init(ti_sn65dsi86_init);
1997 
1998 static void __exit ti_sn65dsi86_exit(void)
1999 {
2000 	auxiliary_driver_unregister(&ti_sn_bridge_driver);
2001 	auxiliary_driver_unregister(&ti_sn_aux_driver);
2002 	ti_sn_pwm_unregister();
2003 	ti_sn_gpio_unregister();
2004 	i2c_del_driver(&ti_sn65dsi86_driver);
2005 }
2006 module_exit(ti_sn65dsi86_exit);
2007 
2008 MODULE_AUTHOR("Sandeep Panda <spanda@codeaurora.org>");
2009 MODULE_DESCRIPTION("sn65dsi86 DSI to eDP bridge driver");
2010 MODULE_LICENSE("GPL v2");
2011