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 	/* avoid buffer overflow and "1" is the default rate in the datasheet. */
302 	if (i >= refclk_lut_size)
303 		i = 1;
304 
305 	regmap_update_bits(pdata->regmap, SN_DPPLL_SRC_REG, REFCLK_FREQ_MASK,
306 			   REFCLK_FREQ(i));
307 
308 	/*
309 	 * The PWM refclk is based on the value written to SN_DPPLL_SRC_REG,
310 	 * regardless of its actual sourcing.
311 	 */
312 	pdata->pwm_refclk_freq = ti_sn_bridge_refclk_lut[i];
313 }
314 
315 static void ti_sn65dsi86_enable_comms(struct ti_sn65dsi86 *pdata)
316 {
317 	mutex_lock(&pdata->comms_mutex);
318 
319 	/* configure bridge ref_clk */
320 	ti_sn_bridge_set_refclk_freq(pdata);
321 
322 	/*
323 	 * HPD on this bridge chip is a bit useless.  This is an eDP bridge
324 	 * so the HPD is an internal signal that's only there to signal that
325 	 * the panel is done powering up.  ...but the bridge chip debounces
326 	 * this signal by between 100 ms and 400 ms (depending on process,
327 	 * voltage, and temperate--I measured it at about 200 ms).  One
328 	 * particular panel asserted HPD 84 ms after it was powered on meaning
329 	 * that we saw HPD 284 ms after power on.  ...but the same panel said
330 	 * that instead of looking at HPD you could just hardcode a delay of
331 	 * 200 ms.  We'll assume that the panel driver will have the hardcoded
332 	 * delay in its prepare and always disable HPD.
333 	 *
334 	 * If HPD somehow makes sense on some future panel we'll have to
335 	 * change this to be conditional on someone specifying that HPD should
336 	 * be used.
337 	 */
338 	regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE,
339 			   HPD_DISABLE);
340 
341 	pdata->comms_enabled = true;
342 
343 	mutex_unlock(&pdata->comms_mutex);
344 }
345 
346 static void ti_sn65dsi86_disable_comms(struct ti_sn65dsi86 *pdata)
347 {
348 	mutex_lock(&pdata->comms_mutex);
349 
350 	pdata->comms_enabled = false;
351 	clk_disable_unprepare(pdata->refclk);
352 
353 	mutex_unlock(&pdata->comms_mutex);
354 }
355 
356 static int __maybe_unused ti_sn65dsi86_resume(struct device *dev)
357 {
358 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(dev);
359 	int ret;
360 
361 	ret = regulator_bulk_enable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies);
362 	if (ret) {
363 		DRM_ERROR("failed to enable supplies %d\n", ret);
364 		return ret;
365 	}
366 
367 	/* td2: min 100 us after regulators before enabling the GPIO */
368 	usleep_range(100, 110);
369 
370 	gpiod_set_value_cansleep(pdata->enable_gpio, 1);
371 
372 	/*
373 	 * If we have a reference clock we can enable communication w/ the
374 	 * panel (including the aux channel) w/out any need for an input clock
375 	 * so we can do it in resume which lets us read the EDID before
376 	 * pre_enable(). Without a reference clock we need the MIPI reference
377 	 * clock so reading early doesn't work.
378 	 */
379 	if (pdata->refclk)
380 		ti_sn65dsi86_enable_comms(pdata);
381 
382 	return ret;
383 }
384 
385 static int __maybe_unused ti_sn65dsi86_suspend(struct device *dev)
386 {
387 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(dev);
388 	int ret;
389 
390 	if (pdata->refclk)
391 		ti_sn65dsi86_disable_comms(pdata);
392 
393 	gpiod_set_value_cansleep(pdata->enable_gpio, 0);
394 
395 	ret = regulator_bulk_disable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies);
396 	if (ret)
397 		DRM_ERROR("failed to disable supplies %d\n", ret);
398 
399 	return ret;
400 }
401 
402 static const struct dev_pm_ops ti_sn65dsi86_pm_ops = {
403 	SET_RUNTIME_PM_OPS(ti_sn65dsi86_suspend, ti_sn65dsi86_resume, NULL)
404 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
405 				pm_runtime_force_resume)
406 };
407 
408 static int status_show(struct seq_file *s, void *data)
409 {
410 	struct ti_sn65dsi86 *pdata = s->private;
411 	unsigned int reg, val;
412 
413 	seq_puts(s, "STATUS REGISTERS:\n");
414 
415 	pm_runtime_get_sync(pdata->dev);
416 
417 	/* IRQ Status Registers, see Table 31 in datasheet */
418 	for (reg = 0xf0; reg <= 0xf8; reg++) {
419 		regmap_read(pdata->regmap, reg, &val);
420 		seq_printf(s, "[0x%02x] = 0x%08x\n", reg, val);
421 	}
422 
423 	pm_runtime_put_autosuspend(pdata->dev);
424 
425 	return 0;
426 }
427 
428 DEFINE_SHOW_ATTRIBUTE(status);
429 
430 static void ti_sn65dsi86_debugfs_remove(void *data)
431 {
432 	debugfs_remove_recursive(data);
433 }
434 
435 static void ti_sn65dsi86_debugfs_init(struct ti_sn65dsi86 *pdata)
436 {
437 	struct device *dev = pdata->dev;
438 	struct dentry *debugfs;
439 	int ret;
440 
441 	debugfs = debugfs_create_dir(dev_name(dev), NULL);
442 
443 	/*
444 	 * We might get an error back if debugfs wasn't enabled in the kernel
445 	 * so let's just silently return upon failure.
446 	 */
447 	if (IS_ERR_OR_NULL(debugfs))
448 		return;
449 
450 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_debugfs_remove, debugfs);
451 	if (ret)
452 		return;
453 
454 	debugfs_create_file("status", 0600, debugfs, pdata, &status_fops);
455 }
456 
457 /* -----------------------------------------------------------------------------
458  * Auxiliary Devices (*not* AUX)
459  */
460 
461 static void ti_sn65dsi86_uninit_aux(void *data)
462 {
463 	auxiliary_device_uninit(data);
464 }
465 
466 static void ti_sn65dsi86_delete_aux(void *data)
467 {
468 	auxiliary_device_delete(data);
469 }
470 
471 /*
472  * AUX bus docs say that a non-NULL release is mandatory, but it makes no
473  * sense for the model used here where all of the aux devices are allocated
474  * in the single shared structure. We'll use this noop as a workaround.
475  */
476 static void ti_sn65dsi86_noop(struct device *dev) {}
477 
478 static int ti_sn65dsi86_add_aux_device(struct ti_sn65dsi86 *pdata,
479 				       struct auxiliary_device *aux,
480 				       const char *name)
481 {
482 	struct device *dev = pdata->dev;
483 	int ret;
484 
485 	aux->name = name;
486 	aux->dev.parent = dev;
487 	aux->dev.release = ti_sn65dsi86_noop;
488 	device_set_of_node_from_dev(&aux->dev, dev);
489 	ret = auxiliary_device_init(aux);
490 	if (ret)
491 		return ret;
492 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_uninit_aux, aux);
493 	if (ret)
494 		return ret;
495 
496 	ret = auxiliary_device_add(aux);
497 	if (ret)
498 		return ret;
499 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_delete_aux, aux);
500 
501 	return ret;
502 }
503 
504 /* -----------------------------------------------------------------------------
505  * AUX Adapter
506  */
507 
508 static struct ti_sn65dsi86 *aux_to_ti_sn65dsi86(struct drm_dp_aux *aux)
509 {
510 	return container_of(aux, struct ti_sn65dsi86, aux);
511 }
512 
513 static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux,
514 				  struct drm_dp_aux_msg *msg)
515 {
516 	struct ti_sn65dsi86 *pdata = aux_to_ti_sn65dsi86(aux);
517 	u32 request = msg->request & ~(DP_AUX_I2C_MOT | DP_AUX_I2C_WRITE_STATUS_UPDATE);
518 	u32 request_val = AUX_CMD_REQ(msg->request);
519 	u8 *buf = msg->buffer;
520 	unsigned int len = msg->size;
521 	unsigned int val;
522 	int ret;
523 	u8 addr_len[SN_AUX_LENGTH_REG + 1 - SN_AUX_ADDR_19_16_REG];
524 
525 	if (len > SN_AUX_MAX_PAYLOAD_BYTES)
526 		return -EINVAL;
527 
528 	pm_runtime_get_sync(pdata->dev);
529 	mutex_lock(&pdata->comms_mutex);
530 
531 	/*
532 	 * If someone tries to do a DDC over AUX transaction before pre_enable()
533 	 * on a device without a dedicated reference clock then we just can't
534 	 * do it. Fail right away. This prevents non-refclk users from reading
535 	 * the EDID before enabling the panel but such is life.
536 	 */
537 	if (!pdata->comms_enabled) {
538 		ret = -EIO;
539 		goto exit;
540 	}
541 
542 	switch (request) {
543 	case DP_AUX_NATIVE_WRITE:
544 	case DP_AUX_I2C_WRITE:
545 	case DP_AUX_NATIVE_READ:
546 	case DP_AUX_I2C_READ:
547 		regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val);
548 		/* Assume it's good */
549 		msg->reply = 0;
550 		break;
551 	default:
552 		ret = -EINVAL;
553 		goto exit;
554 	}
555 
556 	BUILD_BUG_ON(sizeof(addr_len) != sizeof(__be32));
557 	put_unaligned_be32((msg->address & SN_AUX_ADDR_MASK) << 8 | len,
558 			   addr_len);
559 	regmap_bulk_write(pdata->regmap, SN_AUX_ADDR_19_16_REG, addr_len,
560 			  ARRAY_SIZE(addr_len));
561 
562 	if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE)
563 		regmap_bulk_write(pdata->regmap, SN_AUX_WDATA_REG(0), buf, len);
564 
565 	/* Clear old status bits before start so we don't get confused */
566 	regmap_write(pdata->regmap, SN_AUX_CMD_STATUS_REG,
567 		     AUX_IRQ_STATUS_NAT_I2C_FAIL |
568 		     AUX_IRQ_STATUS_AUX_RPLY_TOUT |
569 		     AUX_IRQ_STATUS_AUX_SHORT);
570 
571 	regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val | AUX_CMD_SEND);
572 
573 	/* Zero delay loop because i2c transactions are slow already */
574 	ret = regmap_read_poll_timeout(pdata->regmap, SN_AUX_CMD_REG, val,
575 				       !(val & AUX_CMD_SEND), 0, 50 * 1000);
576 	if (ret)
577 		goto exit;
578 
579 	ret = regmap_read(pdata->regmap, SN_AUX_CMD_STATUS_REG, &val);
580 	if (ret)
581 		goto exit;
582 
583 	if (val & AUX_IRQ_STATUS_AUX_RPLY_TOUT) {
584 		/*
585 		 * The hardware tried the message seven times per the DP spec
586 		 * but it hit a timeout. We ignore defers here because they're
587 		 * handled in hardware.
588 		 */
589 		ret = -ETIMEDOUT;
590 		goto exit;
591 	}
592 
593 	if (val & AUX_IRQ_STATUS_AUX_SHORT) {
594 		ret = regmap_read(pdata->regmap, SN_AUX_LENGTH_REG, &len);
595 		if (ret)
596 			goto exit;
597 	} else if (val & AUX_IRQ_STATUS_NAT_I2C_FAIL) {
598 		switch (request) {
599 		case DP_AUX_I2C_WRITE:
600 		case DP_AUX_I2C_READ:
601 			msg->reply |= DP_AUX_I2C_REPLY_NACK;
602 			break;
603 		case DP_AUX_NATIVE_READ:
604 		case DP_AUX_NATIVE_WRITE:
605 			msg->reply |= DP_AUX_NATIVE_REPLY_NACK;
606 			break;
607 		}
608 		len = 0;
609 		goto exit;
610 	}
611 
612 	if (request != DP_AUX_NATIVE_WRITE && request != DP_AUX_I2C_WRITE && len != 0)
613 		ret = regmap_bulk_read(pdata->regmap, SN_AUX_RDATA_REG(0), buf, len);
614 
615 exit:
616 	mutex_unlock(&pdata->comms_mutex);
617 	pm_runtime_mark_last_busy(pdata->dev);
618 	pm_runtime_put_autosuspend(pdata->dev);
619 
620 	if (ret)
621 		return ret;
622 	return len;
623 }
624 
625 static int ti_sn_aux_probe(struct auxiliary_device *adev,
626 			   const struct auxiliary_device_id *id)
627 {
628 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
629 	int ret;
630 
631 	pdata->aux.name = "ti-sn65dsi86-aux";
632 	pdata->aux.dev = &adev->dev;
633 	pdata->aux.transfer = ti_sn_aux_transfer;
634 	drm_dp_aux_init(&pdata->aux);
635 
636 	ret = devm_of_dp_aux_populate_ep_devices(&pdata->aux);
637 	if (ret)
638 		return ret;
639 
640 	/*
641 	 * The eDP to MIPI bridge parts don't work until the AUX channel is
642 	 * setup so we don't add it in the main driver probe, we add it now.
643 	 */
644 	return ti_sn65dsi86_add_aux_device(pdata, &pdata->bridge_aux, "bridge");
645 }
646 
647 static const struct auxiliary_device_id ti_sn_aux_id_table[] = {
648 	{ .name = "ti_sn65dsi86.aux", },
649 	{},
650 };
651 
652 static struct auxiliary_driver ti_sn_aux_driver = {
653 	.name = "aux",
654 	.probe = ti_sn_aux_probe,
655 	.id_table = ti_sn_aux_id_table,
656 };
657 
658 /*------------------------------------------------------------------------------
659  * DRM Bridge
660  */
661 
662 static struct ti_sn65dsi86 *bridge_to_ti_sn65dsi86(struct drm_bridge *bridge)
663 {
664 	return container_of(bridge, struct ti_sn65dsi86, bridge);
665 }
666 
667 static int ti_sn_attach_host(struct ti_sn65dsi86 *pdata)
668 {
669 	int val;
670 	struct mipi_dsi_host *host;
671 	struct mipi_dsi_device *dsi;
672 	struct device *dev = pdata->dev;
673 	const struct mipi_dsi_device_info info = { .type = "ti_sn_bridge",
674 						   .channel = 0,
675 						   .node = NULL,
676 	};
677 
678 	host = of_find_mipi_dsi_host_by_node(pdata->host_node);
679 	if (!host)
680 		return -EPROBE_DEFER;
681 
682 	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
683 	if (IS_ERR(dsi))
684 		return PTR_ERR(dsi);
685 
686 	/* TODO: setting to 4 MIPI lanes always for now */
687 	dsi->lanes = 4;
688 	dsi->format = MIPI_DSI_FMT_RGB888;
689 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
690 
691 	/* check if continuous dsi clock is required or not */
692 	pm_runtime_get_sync(dev);
693 	regmap_read(pdata->regmap, SN_DPPLL_SRC_REG, &val);
694 	pm_runtime_put_autosuspend(dev);
695 	if (!(val & DPPLL_CLK_SRC_DSICLK))
696 		dsi->mode_flags |= MIPI_DSI_CLOCK_NON_CONTINUOUS;
697 
698 	pdata->dsi = dsi;
699 
700 	return devm_mipi_dsi_attach(dev, dsi);
701 }
702 
703 static int ti_sn_bridge_attach(struct drm_bridge *bridge,
704 			       enum drm_bridge_attach_flags flags)
705 {
706 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
707 	int ret;
708 
709 	pdata->aux.drm_dev = bridge->dev;
710 	ret = drm_dp_aux_register(&pdata->aux);
711 	if (ret < 0) {
712 		drm_err(bridge->dev, "Failed to register DP AUX channel: %d\n", ret);
713 		return ret;
714 	}
715 
716 	/*
717 	 * Attach the next bridge.
718 	 * We never want the next bridge to *also* create a connector.
719 	 */
720 	ret = drm_bridge_attach(bridge->encoder, pdata->next_bridge,
721 				&pdata->bridge, flags | DRM_BRIDGE_ATTACH_NO_CONNECTOR);
722 	if (ret < 0)
723 		goto err_initted_aux;
724 
725 	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
726 		return 0;
727 
728 	pdata->connector = drm_bridge_connector_init(pdata->bridge.dev,
729 						     pdata->bridge.encoder);
730 	if (IS_ERR(pdata->connector)) {
731 		ret = PTR_ERR(pdata->connector);
732 		goto err_initted_aux;
733 	}
734 
735 	drm_connector_attach_encoder(pdata->connector, pdata->bridge.encoder);
736 
737 	return 0;
738 
739 err_initted_aux:
740 	drm_dp_aux_unregister(&pdata->aux);
741 	return ret;
742 }
743 
744 static void ti_sn_bridge_detach(struct drm_bridge *bridge)
745 {
746 	drm_dp_aux_unregister(&bridge_to_ti_sn65dsi86(bridge)->aux);
747 }
748 
749 static enum drm_mode_status
750 ti_sn_bridge_mode_valid(struct drm_bridge *bridge,
751 			const struct drm_display_info *info,
752 			const struct drm_display_mode *mode)
753 {
754 	/* maximum supported resolution is 4K at 60 fps */
755 	if (mode->clock > 594000)
756 		return MODE_CLOCK_HIGH;
757 
758 	/*
759 	 * The front and back porch registers are 8 bits, and pulse width
760 	 * registers are 15 bits, so reject any modes with larger periods.
761 	 */
762 
763 	if ((mode->hsync_start - mode->hdisplay) > 0xff)
764 		return MODE_HBLANK_WIDE;
765 
766 	if ((mode->vsync_start - mode->vdisplay) > 0xff)
767 		return MODE_VBLANK_WIDE;
768 
769 	if ((mode->hsync_end - mode->hsync_start) > 0x7fff)
770 		return MODE_HSYNC_WIDE;
771 
772 	if ((mode->vsync_end - mode->vsync_start) > 0x7fff)
773 		return MODE_VSYNC_WIDE;
774 
775 	if ((mode->htotal - mode->hsync_end) > 0xff)
776 		return MODE_HBLANK_WIDE;
777 
778 	if ((mode->vtotal - mode->vsync_end) > 0xff)
779 		return MODE_VBLANK_WIDE;
780 
781 	return MODE_OK;
782 }
783 
784 static void ti_sn_bridge_atomic_disable(struct drm_bridge *bridge,
785 					struct drm_bridge_state *old_bridge_state)
786 {
787 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
788 
789 	/* disable video stream */
790 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE, 0);
791 }
792 
793 static void ti_sn_bridge_set_dsi_rate(struct ti_sn65dsi86 *pdata)
794 {
795 	unsigned int bit_rate_mhz, clk_freq_mhz;
796 	unsigned int val;
797 	struct drm_display_mode *mode =
798 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
799 
800 	/* set DSIA clk frequency */
801 	bit_rate_mhz = (mode->clock / 1000) *
802 			mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
803 	clk_freq_mhz = bit_rate_mhz / (pdata->dsi->lanes * 2);
804 
805 	/* for each increment in val, frequency increases by 5MHz */
806 	val = (MIN_DSI_CLK_FREQ_MHZ / 5) +
807 		(((clk_freq_mhz - MIN_DSI_CLK_FREQ_MHZ) / 5) & 0xFF);
808 	regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val);
809 }
810 
811 static unsigned int ti_sn_bridge_get_bpp(struct drm_connector *connector)
812 {
813 	if (connector->display_info.bpc <= 6)
814 		return 18;
815 	else
816 		return 24;
817 }
818 
819 /*
820  * LUT index corresponds to register value and
821  * LUT values corresponds to dp data rate supported
822  * by the bridge in Mbps unit.
823  */
824 static const unsigned int ti_sn_bridge_dp_rate_lut[] = {
825 	0, 1620, 2160, 2430, 2700, 3240, 4320, 5400
826 };
827 
828 static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn65dsi86 *pdata, unsigned int bpp)
829 {
830 	unsigned int bit_rate_khz, dp_rate_mhz;
831 	unsigned int i;
832 	struct drm_display_mode *mode =
833 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
834 
835 	/* Calculate minimum bit rate based on our pixel clock. */
836 	bit_rate_khz = mode->clock * bpp;
837 
838 	/* Calculate minimum DP data rate, taking 80% as per DP spec */
839 	dp_rate_mhz = DIV_ROUND_UP(bit_rate_khz * DP_CLK_FUDGE_NUM,
840 				   1000 * pdata->dp_lanes * DP_CLK_FUDGE_DEN);
841 
842 	for (i = 1; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++)
843 		if (ti_sn_bridge_dp_rate_lut[i] >= dp_rate_mhz)
844 			break;
845 
846 	return i;
847 }
848 
849 static unsigned int ti_sn_bridge_read_valid_rates(struct ti_sn65dsi86 *pdata)
850 {
851 	unsigned int valid_rates = 0;
852 	unsigned int rate_per_200khz;
853 	unsigned int rate_mhz;
854 	u8 dpcd_val;
855 	int ret;
856 	int i, j;
857 
858 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_EDP_DPCD_REV, &dpcd_val);
859 	if (ret != 1) {
860 		DRM_DEV_ERROR(pdata->dev,
861 			      "Can't read eDP rev (%d), assuming 1.1\n", ret);
862 		dpcd_val = DP_EDP_11;
863 	}
864 
865 	if (dpcd_val >= DP_EDP_14) {
866 		/* eDP 1.4 devices must provide a custom table */
867 		__le16 sink_rates[DP_MAX_SUPPORTED_RATES];
868 
869 		ret = drm_dp_dpcd_read(&pdata->aux, DP_SUPPORTED_LINK_RATES,
870 				       sink_rates, sizeof(sink_rates));
871 
872 		if (ret != sizeof(sink_rates)) {
873 			DRM_DEV_ERROR(pdata->dev,
874 				"Can't read supported rate table (%d)\n", ret);
875 
876 			/* By zeroing we'll fall back to DP_MAX_LINK_RATE. */
877 			memset(sink_rates, 0, sizeof(sink_rates));
878 		}
879 
880 		for (i = 0; i < ARRAY_SIZE(sink_rates); i++) {
881 			rate_per_200khz = le16_to_cpu(sink_rates[i]);
882 
883 			if (!rate_per_200khz)
884 				break;
885 
886 			rate_mhz = rate_per_200khz * 200 / 1000;
887 			for (j = 0;
888 			     j < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
889 			     j++) {
890 				if (ti_sn_bridge_dp_rate_lut[j] == rate_mhz)
891 					valid_rates |= BIT(j);
892 			}
893 		}
894 
895 		for (i = 0; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut); i++) {
896 			if (valid_rates & BIT(i))
897 				return valid_rates;
898 		}
899 		DRM_DEV_ERROR(pdata->dev,
900 			      "No matching eDP rates in table; falling back\n");
901 	}
902 
903 	/* On older versions best we can do is use DP_MAX_LINK_RATE */
904 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LINK_RATE, &dpcd_val);
905 	if (ret != 1) {
906 		DRM_DEV_ERROR(pdata->dev,
907 			      "Can't read max rate (%d); assuming 5.4 GHz\n",
908 			      ret);
909 		dpcd_val = DP_LINK_BW_5_4;
910 	}
911 
912 	switch (dpcd_val) {
913 	default:
914 		DRM_DEV_ERROR(pdata->dev,
915 			      "Unexpected max rate (%#x); assuming 5.4 GHz\n",
916 			      (int)dpcd_val);
917 		fallthrough;
918 	case DP_LINK_BW_5_4:
919 		valid_rates |= BIT(7);
920 		fallthrough;
921 	case DP_LINK_BW_2_7:
922 		valid_rates |= BIT(4);
923 		fallthrough;
924 	case DP_LINK_BW_1_62:
925 		valid_rates |= BIT(1);
926 		break;
927 	}
928 
929 	return valid_rates;
930 }
931 
932 static void ti_sn_bridge_set_video_timings(struct ti_sn65dsi86 *pdata)
933 {
934 	struct drm_display_mode *mode =
935 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
936 	u8 hsync_polarity = 0, vsync_polarity = 0;
937 
938 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
939 		hsync_polarity = CHA_HSYNC_POLARITY;
940 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
941 		vsync_polarity = CHA_VSYNC_POLARITY;
942 
943 	ti_sn65dsi86_write_u16(pdata, SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG,
944 			       mode->hdisplay);
945 	ti_sn65dsi86_write_u16(pdata, SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG,
946 			       mode->vdisplay);
947 	regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG,
948 		     (mode->hsync_end - mode->hsync_start) & 0xFF);
949 	regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_HIGH_REG,
950 		     (((mode->hsync_end - mode->hsync_start) >> 8) & 0x7F) |
951 		     hsync_polarity);
952 	regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG,
953 		     (mode->vsync_end - mode->vsync_start) & 0xFF);
954 	regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_HIGH_REG,
955 		     (((mode->vsync_end - mode->vsync_start) >> 8) & 0x7F) |
956 		     vsync_polarity);
957 
958 	regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_BACK_PORCH_REG,
959 		     (mode->htotal - mode->hsync_end) & 0xFF);
960 	regmap_write(pdata->regmap, SN_CHA_VERTICAL_BACK_PORCH_REG,
961 		     (mode->vtotal - mode->vsync_end) & 0xFF);
962 
963 	regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_FRONT_PORCH_REG,
964 		     (mode->hsync_start - mode->hdisplay) & 0xFF);
965 	regmap_write(pdata->regmap, SN_CHA_VERTICAL_FRONT_PORCH_REG,
966 		     (mode->vsync_start - mode->vdisplay) & 0xFF);
967 
968 	usleep_range(10000, 10500); /* 10ms delay recommended by spec */
969 }
970 
971 static unsigned int ti_sn_get_max_lanes(struct ti_sn65dsi86 *pdata)
972 {
973 	u8 data;
974 	int ret;
975 
976 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LANE_COUNT, &data);
977 	if (ret != 1) {
978 		DRM_DEV_ERROR(pdata->dev,
979 			      "Can't read lane count (%d); assuming 4\n", ret);
980 		return 4;
981 	}
982 
983 	return data & DP_LANE_COUNT_MASK;
984 }
985 
986 static int ti_sn_link_training(struct ti_sn65dsi86 *pdata, int dp_rate_idx,
987 			       const char **last_err_str)
988 {
989 	unsigned int val;
990 	int ret;
991 	int i;
992 
993 	/* set dp clk frequency value */
994 	regmap_update_bits(pdata->regmap, SN_DATARATE_CONFIG_REG,
995 			   DP_DATARATE_MASK, DP_DATARATE(dp_rate_idx));
996 
997 	/* enable DP PLL */
998 	regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
999 
1000 	ret = regmap_read_poll_timeout(pdata->regmap, SN_DPPLL_SRC_REG, val,
1001 				       val & DPPLL_SRC_DP_PLL_LOCK, 1000,
1002 				       50 * 1000);
1003 	if (ret) {
1004 		*last_err_str = "DP_PLL_LOCK polling failed";
1005 		goto exit;
1006 	}
1007 
1008 	/*
1009 	 * We'll try to link train several times.  As part of link training
1010 	 * the bridge chip will write DP_SET_POWER_D0 to DP_SET_POWER.  If
1011 	 * the panel isn't ready quite it might respond NAK here which means
1012 	 * we need to try again.
1013 	 */
1014 	for (i = 0; i < SN_LINK_TRAINING_TRIES; i++) {
1015 		/* Semi auto link training mode */
1016 		regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A);
1017 		ret = regmap_read_poll_timeout(pdata->regmap, SN_ML_TX_MODE_REG, val,
1018 					       val == ML_TX_MAIN_LINK_OFF ||
1019 					       val == ML_TX_NORMAL_MODE, 1000,
1020 					       500 * 1000);
1021 		if (ret) {
1022 			*last_err_str = "Training complete polling failed";
1023 		} else if (val == ML_TX_MAIN_LINK_OFF) {
1024 			*last_err_str = "Link training failed, link is off";
1025 			ret = -EIO;
1026 			continue;
1027 		}
1028 
1029 		break;
1030 	}
1031 
1032 	/* If we saw quite a few retries, add a note about it */
1033 	if (!ret && i > SN_LINK_TRAINING_TRIES / 2)
1034 		DRM_DEV_INFO(pdata->dev, "Link training needed %d retries\n", i);
1035 
1036 exit:
1037 	/* Disable the PLL if we failed */
1038 	if (ret)
1039 		regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
1040 
1041 	return ret;
1042 }
1043 
1044 static void ti_sn_bridge_atomic_enable(struct drm_bridge *bridge,
1045 				       struct drm_bridge_state *old_bridge_state)
1046 {
1047 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1048 	struct drm_connector *connector;
1049 	const char *last_err_str = "No supported DP rate";
1050 	unsigned int valid_rates;
1051 	int dp_rate_idx;
1052 	unsigned int val;
1053 	int ret = -EINVAL;
1054 	int max_dp_lanes;
1055 	unsigned int bpp;
1056 
1057 	connector = drm_atomic_get_new_connector_for_encoder(old_bridge_state->base.state,
1058 							     bridge->encoder);
1059 	if (!connector) {
1060 		dev_err_ratelimited(pdata->dev, "Could not get the connector\n");
1061 		return;
1062 	}
1063 
1064 	max_dp_lanes = ti_sn_get_max_lanes(pdata);
1065 	pdata->dp_lanes = min(pdata->dp_lanes, max_dp_lanes);
1066 
1067 	/* DSI_A lane config */
1068 	val = CHA_DSI_LANES(SN_MAX_DP_LANES - pdata->dsi->lanes);
1069 	regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG,
1070 			   CHA_DSI_LANES_MASK, val);
1071 
1072 	regmap_write(pdata->regmap, SN_LN_ASSIGN_REG, pdata->ln_assign);
1073 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, LN_POLRS_MASK,
1074 			   pdata->ln_polrs << LN_POLRS_OFFSET);
1075 
1076 	/* set dsi clk frequency value */
1077 	ti_sn_bridge_set_dsi_rate(pdata);
1078 
1079 	/*
1080 	 * The SN65DSI86 only supports ASSR Display Authentication method and
1081 	 * this method is enabled for eDP panels. An eDP panel must support this
1082 	 * authentication method. We need to enable this method in the eDP panel
1083 	 * at DisplayPort address 0x0010A prior to link training.
1084 	 *
1085 	 * As only ASSR is supported by SN65DSI86, for full DisplayPort displays
1086 	 * we need to disable the scrambler.
1087 	 */
1088 	if (pdata->bridge.type == DRM_MODE_CONNECTOR_eDP) {
1089 		drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET,
1090 				   DP_ALTERNATE_SCRAMBLER_RESET_ENABLE);
1091 
1092 		regmap_update_bits(pdata->regmap, SN_TRAINING_SETTING_REG,
1093 				   SCRAMBLE_DISABLE, 0);
1094 	} else {
1095 		regmap_update_bits(pdata->regmap, SN_TRAINING_SETTING_REG,
1096 				   SCRAMBLE_DISABLE, SCRAMBLE_DISABLE);
1097 	}
1098 
1099 	bpp = ti_sn_bridge_get_bpp(connector);
1100 	/* Set the DP output format (18 bpp or 24 bpp) */
1101 	val = bpp == 18 ? BPP_18_RGB : 0;
1102 	regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val);
1103 
1104 	/* DP lane config */
1105 	val = DP_NUM_LANES(min(pdata->dp_lanes, 3));
1106 	regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK,
1107 			   val);
1108 
1109 	valid_rates = ti_sn_bridge_read_valid_rates(pdata);
1110 
1111 	/* Train until we run out of rates */
1112 	for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata, bpp);
1113 	     dp_rate_idx < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
1114 	     dp_rate_idx++) {
1115 		if (!(valid_rates & BIT(dp_rate_idx)))
1116 			continue;
1117 
1118 		ret = ti_sn_link_training(pdata, dp_rate_idx, &last_err_str);
1119 		if (!ret)
1120 			break;
1121 	}
1122 	if (ret) {
1123 		DRM_DEV_ERROR(pdata->dev, "%s (%d)\n", last_err_str, ret);
1124 		return;
1125 	}
1126 
1127 	/* config video parameters */
1128 	ti_sn_bridge_set_video_timings(pdata);
1129 
1130 	/* enable video stream */
1131 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE,
1132 			   VSTREAM_ENABLE);
1133 }
1134 
1135 static void ti_sn_bridge_atomic_pre_enable(struct drm_bridge *bridge,
1136 					   struct drm_bridge_state *old_bridge_state)
1137 {
1138 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1139 
1140 	pm_runtime_get_sync(pdata->dev);
1141 
1142 	if (!pdata->refclk)
1143 		ti_sn65dsi86_enable_comms(pdata);
1144 
1145 	/* td7: min 100 us after enable before DSI data */
1146 	usleep_range(100, 110);
1147 }
1148 
1149 static void ti_sn_bridge_atomic_post_disable(struct drm_bridge *bridge,
1150 					     struct drm_bridge_state *old_bridge_state)
1151 {
1152 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1153 
1154 	/* semi auto link training mode OFF */
1155 	regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0);
1156 	/* Num lanes to 0 as per power sequencing in data sheet */
1157 	regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, 0);
1158 	/* disable DP PLL */
1159 	regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
1160 
1161 	if (!pdata->refclk)
1162 		ti_sn65dsi86_disable_comms(pdata);
1163 
1164 	pm_runtime_put_sync(pdata->dev);
1165 }
1166 
1167 static enum drm_connector_status ti_sn_bridge_detect(struct drm_bridge *bridge)
1168 {
1169 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1170 	int val = 0;
1171 
1172 	pm_runtime_get_sync(pdata->dev);
1173 	regmap_read(pdata->regmap, SN_HPD_DISABLE_REG, &val);
1174 	pm_runtime_put_autosuspend(pdata->dev);
1175 
1176 	return val & HPD_DEBOUNCED_STATE ? connector_status_connected
1177 					 : connector_status_disconnected;
1178 }
1179 
1180 static struct edid *ti_sn_bridge_get_edid(struct drm_bridge *bridge,
1181 					  struct drm_connector *connector)
1182 {
1183 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1184 
1185 	return drm_get_edid(connector, &pdata->aux.ddc);
1186 }
1187 
1188 static const struct drm_bridge_funcs ti_sn_bridge_funcs = {
1189 	.attach = ti_sn_bridge_attach,
1190 	.detach = ti_sn_bridge_detach,
1191 	.mode_valid = ti_sn_bridge_mode_valid,
1192 	.get_edid = ti_sn_bridge_get_edid,
1193 	.detect = ti_sn_bridge_detect,
1194 	.atomic_pre_enable = ti_sn_bridge_atomic_pre_enable,
1195 	.atomic_enable = ti_sn_bridge_atomic_enable,
1196 	.atomic_disable = ti_sn_bridge_atomic_disable,
1197 	.atomic_post_disable = ti_sn_bridge_atomic_post_disable,
1198 	.atomic_reset = drm_atomic_helper_bridge_reset,
1199 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
1200 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
1201 };
1202 
1203 static void ti_sn_bridge_parse_lanes(struct ti_sn65dsi86 *pdata,
1204 				     struct device_node *np)
1205 {
1206 	u32 lane_assignments[SN_MAX_DP_LANES] = { 0, 1, 2, 3 };
1207 	u32 lane_polarities[SN_MAX_DP_LANES] = { };
1208 	struct device_node *endpoint;
1209 	u8 ln_assign = 0;
1210 	u8 ln_polrs = 0;
1211 	int dp_lanes;
1212 	int i;
1213 
1214 	/*
1215 	 * Read config from the device tree about lane remapping and lane
1216 	 * polarities.  These are optional and we assume identity map and
1217 	 * normal polarity if nothing is specified.  It's OK to specify just
1218 	 * data-lanes but not lane-polarities but not vice versa.
1219 	 *
1220 	 * Error checking is light (we just make sure we don't crash or
1221 	 * buffer overrun) and we assume dts is well formed and specifying
1222 	 * mappings that the hardware supports.
1223 	 */
1224 	endpoint = of_graph_get_endpoint_by_regs(np, 1, -1);
1225 	dp_lanes = drm_of_get_data_lanes_count(endpoint, 1, SN_MAX_DP_LANES);
1226 	if (dp_lanes > 0) {
1227 		of_property_read_u32_array(endpoint, "data-lanes",
1228 					   lane_assignments, dp_lanes);
1229 		of_property_read_u32_array(endpoint, "lane-polarities",
1230 					   lane_polarities, dp_lanes);
1231 	} else {
1232 		dp_lanes = SN_MAX_DP_LANES;
1233 	}
1234 	of_node_put(endpoint);
1235 
1236 	/*
1237 	 * Convert into register format.  Loop over all lanes even if
1238 	 * data-lanes had fewer elements so that we nicely initialize
1239 	 * the LN_ASSIGN register.
1240 	 */
1241 	for (i = SN_MAX_DP_LANES - 1; i >= 0; i--) {
1242 		ln_assign = ln_assign << LN_ASSIGN_WIDTH | lane_assignments[i];
1243 		ln_polrs = ln_polrs << 1 | lane_polarities[i];
1244 	}
1245 
1246 	/* Stash in our struct for when we power on */
1247 	pdata->dp_lanes = dp_lanes;
1248 	pdata->ln_assign = ln_assign;
1249 	pdata->ln_polrs = ln_polrs;
1250 }
1251 
1252 static int ti_sn_bridge_parse_dsi_host(struct ti_sn65dsi86 *pdata)
1253 {
1254 	struct device_node *np = pdata->dev->of_node;
1255 
1256 	pdata->host_node = of_graph_get_remote_node(np, 0, 0);
1257 
1258 	if (!pdata->host_node) {
1259 		DRM_ERROR("remote dsi host node not found\n");
1260 		return -ENODEV;
1261 	}
1262 
1263 	return 0;
1264 }
1265 
1266 static int ti_sn_bridge_probe(struct auxiliary_device *adev,
1267 			      const struct auxiliary_device_id *id)
1268 {
1269 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1270 	struct device_node *np = pdata->dev->of_node;
1271 	int ret;
1272 
1273 	pdata->next_bridge = devm_drm_of_get_bridge(pdata->dev, np, 1, 0);
1274 	if (IS_ERR(pdata->next_bridge))
1275 		return dev_err_probe(pdata->dev, PTR_ERR(pdata->next_bridge),
1276 				     "failed to create panel bridge\n");
1277 
1278 	ti_sn_bridge_parse_lanes(pdata, np);
1279 
1280 	ret = ti_sn_bridge_parse_dsi_host(pdata);
1281 	if (ret)
1282 		return ret;
1283 
1284 	pdata->bridge.funcs = &ti_sn_bridge_funcs;
1285 	pdata->bridge.of_node = np;
1286 	pdata->bridge.type = pdata->next_bridge->type == DRM_MODE_CONNECTOR_DisplayPort
1287 			   ? DRM_MODE_CONNECTOR_DisplayPort : DRM_MODE_CONNECTOR_eDP;
1288 
1289 	if (pdata->bridge.type == DRM_MODE_CONNECTOR_DisplayPort)
1290 		pdata->bridge.ops = DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_DETECT;
1291 
1292 	drm_bridge_add(&pdata->bridge);
1293 
1294 	ret = ti_sn_attach_host(pdata);
1295 	if (ret) {
1296 		dev_err_probe(pdata->dev, ret, "failed to attach dsi host\n");
1297 		goto err_remove_bridge;
1298 	}
1299 
1300 	return 0;
1301 
1302 err_remove_bridge:
1303 	drm_bridge_remove(&pdata->bridge);
1304 	return ret;
1305 }
1306 
1307 static void ti_sn_bridge_remove(struct auxiliary_device *adev)
1308 {
1309 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1310 
1311 	if (!pdata)
1312 		return;
1313 
1314 	drm_bridge_remove(&pdata->bridge);
1315 
1316 	of_node_put(pdata->host_node);
1317 }
1318 
1319 static const struct auxiliary_device_id ti_sn_bridge_id_table[] = {
1320 	{ .name = "ti_sn65dsi86.bridge", },
1321 	{},
1322 };
1323 
1324 static struct auxiliary_driver ti_sn_bridge_driver = {
1325 	.name = "bridge",
1326 	.probe = ti_sn_bridge_probe,
1327 	.remove = ti_sn_bridge_remove,
1328 	.id_table = ti_sn_bridge_id_table,
1329 };
1330 
1331 /* -----------------------------------------------------------------------------
1332  * PWM Controller
1333  */
1334 #if defined(CONFIG_PWM)
1335 static int ti_sn_pwm_pin_request(struct ti_sn65dsi86 *pdata)
1336 {
1337 	return atomic_xchg(&pdata->pwm_pin_busy, 1) ? -EBUSY : 0;
1338 }
1339 
1340 static void ti_sn_pwm_pin_release(struct ti_sn65dsi86 *pdata)
1341 {
1342 	atomic_set(&pdata->pwm_pin_busy, 0);
1343 }
1344 
1345 static struct ti_sn65dsi86 *pwm_chip_to_ti_sn_bridge(struct pwm_chip *chip)
1346 {
1347 	return container_of(chip, struct ti_sn65dsi86, pchip);
1348 }
1349 
1350 static int ti_sn_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
1351 {
1352 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1353 
1354 	return ti_sn_pwm_pin_request(pdata);
1355 }
1356 
1357 static void ti_sn_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
1358 {
1359 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1360 
1361 	ti_sn_pwm_pin_release(pdata);
1362 }
1363 
1364 /*
1365  * Limitations:
1366  * - The PWM signal is not driven when the chip is powered down, or in its
1367  *   reset state and the driver does not implement the "suspend state"
1368  *   described in the documentation. In order to save power, state->enabled is
1369  *   interpreted as denoting if the signal is expected to be valid, and is used
1370  *   to determine if the chip needs to be kept powered.
1371  * - Changing both period and duty_cycle is not done atomically, neither is the
1372  *   multi-byte register updates, so the output might briefly be undefined
1373  *   during update.
1374  */
1375 static int ti_sn_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
1376 			   const struct pwm_state *state)
1377 {
1378 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1379 	unsigned int pwm_en_inv;
1380 	unsigned int backlight;
1381 	unsigned int pre_div;
1382 	unsigned int scale;
1383 	u64 period_max;
1384 	u64 period;
1385 	int ret;
1386 
1387 	if (!pdata->pwm_enabled) {
1388 		ret = pm_runtime_get_sync(pdata->dev);
1389 		if (ret < 0) {
1390 			pm_runtime_put_sync(pdata->dev);
1391 			return ret;
1392 		}
1393 	}
1394 
1395 	if (state->enabled) {
1396 		if (!pdata->pwm_enabled) {
1397 			/*
1398 			 * The chip might have been powered down while we
1399 			 * didn't hold a PM runtime reference, so mux in the
1400 			 * PWM function on the GPIO pin again.
1401 			 */
1402 			ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1403 						 SN_GPIO_MUX_MASK << (2 * SN_PWM_GPIO_IDX),
1404 						 SN_GPIO_MUX_SPECIAL << (2 * SN_PWM_GPIO_IDX));
1405 			if (ret) {
1406 				dev_err(pdata->dev, "failed to mux in PWM function\n");
1407 				goto out;
1408 			}
1409 		}
1410 
1411 		/*
1412 		 * Per the datasheet the PWM frequency is given by:
1413 		 *
1414 		 *                          REFCLK_FREQ
1415 		 *   PWM_FREQ = -----------------------------------
1416 		 *               PWM_PRE_DIV * BACKLIGHT_SCALE + 1
1417 		 *
1418 		 * However, after careful review the author is convinced that
1419 		 * the documentation has lost some parenthesis around
1420 		 * "BACKLIGHT_SCALE + 1".
1421 		 *
1422 		 * With the period T_pwm = 1/PWM_FREQ this can be written:
1423 		 *
1424 		 *   T_pwm * REFCLK_FREQ = PWM_PRE_DIV * (BACKLIGHT_SCALE + 1)
1425 		 *
1426 		 * In order to keep BACKLIGHT_SCALE within its 16 bits,
1427 		 * PWM_PRE_DIV must be:
1428 		 *
1429 		 *                     T_pwm * REFCLK_FREQ
1430 		 *   PWM_PRE_DIV >= -------------------------
1431 		 *                   BACKLIGHT_SCALE_MAX + 1
1432 		 *
1433 		 * To simplify the search and to favour higher resolution of
1434 		 * the duty cycle over accuracy of the period, the lowest
1435 		 * possible PWM_PRE_DIV is used. Finally the scale is
1436 		 * calculated as:
1437 		 *
1438 		 *                      T_pwm * REFCLK_FREQ
1439 		 *   BACKLIGHT_SCALE = ---------------------- - 1
1440 		 *                          PWM_PRE_DIV
1441 		 *
1442 		 * Here T_pwm is represented in seconds, so appropriate scaling
1443 		 * to nanoseconds is necessary.
1444 		 */
1445 
1446 		/* Minimum T_pwm is 1 / REFCLK_FREQ */
1447 		if (state->period <= NSEC_PER_SEC / pdata->pwm_refclk_freq) {
1448 			ret = -EINVAL;
1449 			goto out;
1450 		}
1451 
1452 		/*
1453 		 * Maximum T_pwm is 255 * (65535 + 1) / REFCLK_FREQ
1454 		 * Limit period to this to avoid overflows
1455 		 */
1456 		period_max = div_u64((u64)NSEC_PER_SEC * 255 * (65535 + 1),
1457 				     pdata->pwm_refclk_freq);
1458 		period = min(state->period, period_max);
1459 
1460 		pre_div = DIV64_U64_ROUND_UP(period * pdata->pwm_refclk_freq,
1461 					     (u64)NSEC_PER_SEC * (BACKLIGHT_SCALE_MAX + 1));
1462 		scale = div64_u64(period * pdata->pwm_refclk_freq, (u64)NSEC_PER_SEC * pre_div) - 1;
1463 
1464 		/*
1465 		 * The documentation has the duty ratio given as:
1466 		 *
1467 		 *     duty          BACKLIGHT
1468 		 *   ------- = ---------------------
1469 		 *    period    BACKLIGHT_SCALE + 1
1470 		 *
1471 		 * Solve for BACKLIGHT, substituting BACKLIGHT_SCALE according
1472 		 * to definition above and adjusting for nanosecond
1473 		 * representation of duty cycle gives us:
1474 		 */
1475 		backlight = div64_u64(state->duty_cycle * pdata->pwm_refclk_freq,
1476 				      (u64)NSEC_PER_SEC * pre_div);
1477 		if (backlight > scale)
1478 			backlight = scale;
1479 
1480 		ret = regmap_write(pdata->regmap, SN_PWM_PRE_DIV_REG, pre_div);
1481 		if (ret) {
1482 			dev_err(pdata->dev, "failed to update PWM_PRE_DIV\n");
1483 			goto out;
1484 		}
1485 
1486 		ti_sn65dsi86_write_u16(pdata, SN_BACKLIGHT_SCALE_REG, scale);
1487 		ti_sn65dsi86_write_u16(pdata, SN_BACKLIGHT_REG, backlight);
1488 	}
1489 
1490 	pwm_en_inv = FIELD_PREP(SN_PWM_EN_MASK, state->enabled) |
1491 		     FIELD_PREP(SN_PWM_INV_MASK, state->polarity == PWM_POLARITY_INVERSED);
1492 	ret = regmap_write(pdata->regmap, SN_PWM_EN_INV_REG, pwm_en_inv);
1493 	if (ret) {
1494 		dev_err(pdata->dev, "failed to update PWM_EN/PWM_INV\n");
1495 		goto out;
1496 	}
1497 
1498 	pdata->pwm_enabled = state->enabled;
1499 out:
1500 
1501 	if (!pdata->pwm_enabled)
1502 		pm_runtime_put_sync(pdata->dev);
1503 
1504 	return ret;
1505 }
1506 
1507 static int ti_sn_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
1508 			       struct pwm_state *state)
1509 {
1510 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1511 	unsigned int pwm_en_inv;
1512 	unsigned int pre_div;
1513 	u16 backlight;
1514 	u16 scale;
1515 	int ret;
1516 
1517 	ret = regmap_read(pdata->regmap, SN_PWM_EN_INV_REG, &pwm_en_inv);
1518 	if (ret)
1519 		return ret;
1520 
1521 	ret = ti_sn65dsi86_read_u16(pdata, SN_BACKLIGHT_SCALE_REG, &scale);
1522 	if (ret)
1523 		return ret;
1524 
1525 	ret = ti_sn65dsi86_read_u16(pdata, SN_BACKLIGHT_REG, &backlight);
1526 	if (ret)
1527 		return ret;
1528 
1529 	ret = regmap_read(pdata->regmap, SN_PWM_PRE_DIV_REG, &pre_div);
1530 	if (ret)
1531 		return ret;
1532 
1533 	state->enabled = FIELD_GET(SN_PWM_EN_MASK, pwm_en_inv);
1534 	if (FIELD_GET(SN_PWM_INV_MASK, pwm_en_inv))
1535 		state->polarity = PWM_POLARITY_INVERSED;
1536 	else
1537 		state->polarity = PWM_POLARITY_NORMAL;
1538 
1539 	state->period = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * pre_div * (scale + 1),
1540 					 pdata->pwm_refclk_freq);
1541 	state->duty_cycle = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * pre_div * backlight,
1542 					     pdata->pwm_refclk_freq);
1543 
1544 	if (state->duty_cycle > state->period)
1545 		state->duty_cycle = state->period;
1546 
1547 	return 0;
1548 }
1549 
1550 static const struct pwm_ops ti_sn_pwm_ops = {
1551 	.request = ti_sn_pwm_request,
1552 	.free = ti_sn_pwm_free,
1553 	.apply = ti_sn_pwm_apply,
1554 	.get_state = ti_sn_pwm_get_state,
1555 	.owner = THIS_MODULE,
1556 };
1557 
1558 static int ti_sn_pwm_probe(struct auxiliary_device *adev,
1559 			   const struct auxiliary_device_id *id)
1560 {
1561 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1562 
1563 	pdata->pchip.dev = pdata->dev;
1564 	pdata->pchip.ops = &ti_sn_pwm_ops;
1565 	pdata->pchip.npwm = 1;
1566 	pdata->pchip.of_xlate = of_pwm_single_xlate;
1567 	pdata->pchip.of_pwm_n_cells = 1;
1568 
1569 	return pwmchip_add(&pdata->pchip);
1570 }
1571 
1572 static void ti_sn_pwm_remove(struct auxiliary_device *adev)
1573 {
1574 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1575 
1576 	pwmchip_remove(&pdata->pchip);
1577 
1578 	if (pdata->pwm_enabled)
1579 		pm_runtime_put_sync(pdata->dev);
1580 }
1581 
1582 static const struct auxiliary_device_id ti_sn_pwm_id_table[] = {
1583 	{ .name = "ti_sn65dsi86.pwm", },
1584 	{},
1585 };
1586 
1587 static struct auxiliary_driver ti_sn_pwm_driver = {
1588 	.name = "pwm",
1589 	.probe = ti_sn_pwm_probe,
1590 	.remove = ti_sn_pwm_remove,
1591 	.id_table = ti_sn_pwm_id_table,
1592 };
1593 
1594 static int __init ti_sn_pwm_register(void)
1595 {
1596 	return auxiliary_driver_register(&ti_sn_pwm_driver);
1597 }
1598 
1599 static void ti_sn_pwm_unregister(void)
1600 {
1601 	auxiliary_driver_unregister(&ti_sn_pwm_driver);
1602 }
1603 
1604 #else
1605 static inline int ti_sn_pwm_pin_request(struct ti_sn65dsi86 *pdata) { return 0; }
1606 static inline void ti_sn_pwm_pin_release(struct ti_sn65dsi86 *pdata) {}
1607 
1608 static inline int ti_sn_pwm_register(void) { return 0; }
1609 static inline void ti_sn_pwm_unregister(void) {}
1610 #endif
1611 
1612 /* -----------------------------------------------------------------------------
1613  * GPIO Controller
1614  */
1615 #if defined(CONFIG_OF_GPIO)
1616 
1617 static int tn_sn_bridge_of_xlate(struct gpio_chip *chip,
1618 				 const struct of_phandle_args *gpiospec,
1619 				 u32 *flags)
1620 {
1621 	if (WARN_ON(gpiospec->args_count < chip->of_gpio_n_cells))
1622 		return -EINVAL;
1623 
1624 	if (gpiospec->args[0] > chip->ngpio || gpiospec->args[0] < 1)
1625 		return -EINVAL;
1626 
1627 	if (flags)
1628 		*flags = gpiospec->args[1];
1629 
1630 	return gpiospec->args[0] - SN_GPIO_PHYSICAL_OFFSET;
1631 }
1632 
1633 static int ti_sn_bridge_gpio_get_direction(struct gpio_chip *chip,
1634 					   unsigned int offset)
1635 {
1636 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1637 
1638 	/*
1639 	 * We already have to keep track of the direction because we use
1640 	 * that to figure out whether we've powered the device.  We can
1641 	 * just return that rather than (maybe) powering up the device
1642 	 * to ask its direction.
1643 	 */
1644 	return test_bit(offset, pdata->gchip_output) ?
1645 		GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
1646 }
1647 
1648 static int ti_sn_bridge_gpio_get(struct gpio_chip *chip, unsigned int offset)
1649 {
1650 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1651 	unsigned int val;
1652 	int ret;
1653 
1654 	/*
1655 	 * When the pin is an input we don't forcibly keep the bridge
1656 	 * powered--we just power it on to read the pin.  NOTE: part of
1657 	 * the reason this works is that the bridge defaults (when
1658 	 * powered back on) to all 4 GPIOs being configured as GPIO input.
1659 	 * Also note that if something else is keeping the chip powered the
1660 	 * pm_runtime functions are lightweight increments of a refcount.
1661 	 */
1662 	pm_runtime_get_sync(pdata->dev);
1663 	ret = regmap_read(pdata->regmap, SN_GPIO_IO_REG, &val);
1664 	pm_runtime_put_autosuspend(pdata->dev);
1665 
1666 	if (ret)
1667 		return ret;
1668 
1669 	return !!(val & BIT(SN_GPIO_INPUT_SHIFT + offset));
1670 }
1671 
1672 static void ti_sn_bridge_gpio_set(struct gpio_chip *chip, unsigned int offset,
1673 				  int val)
1674 {
1675 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1676 	int ret;
1677 
1678 	if (!test_bit(offset, pdata->gchip_output)) {
1679 		dev_err(pdata->dev, "Ignoring GPIO set while input\n");
1680 		return;
1681 	}
1682 
1683 	val &= 1;
1684 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_IO_REG,
1685 				 BIT(SN_GPIO_OUTPUT_SHIFT + offset),
1686 				 val << (SN_GPIO_OUTPUT_SHIFT + offset));
1687 	if (ret)
1688 		dev_warn(pdata->dev,
1689 			 "Failed to set bridge GPIO %u: %d\n", offset, ret);
1690 }
1691 
1692 static int ti_sn_bridge_gpio_direction_input(struct gpio_chip *chip,
1693 					     unsigned int offset)
1694 {
1695 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1696 	int shift = offset * 2;
1697 	int ret;
1698 
1699 	if (!test_and_clear_bit(offset, pdata->gchip_output))
1700 		return 0;
1701 
1702 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1703 				 SN_GPIO_MUX_MASK << shift,
1704 				 SN_GPIO_MUX_INPUT << shift);
1705 	if (ret) {
1706 		set_bit(offset, pdata->gchip_output);
1707 		return ret;
1708 	}
1709 
1710 	/*
1711 	 * NOTE: if nobody else is powering the device this may fully power
1712 	 * it off and when it comes back it will have lost all state, but
1713 	 * that's OK because the default is input and we're now an input.
1714 	 */
1715 	pm_runtime_put_autosuspend(pdata->dev);
1716 
1717 	return 0;
1718 }
1719 
1720 static int ti_sn_bridge_gpio_direction_output(struct gpio_chip *chip,
1721 					      unsigned int offset, int val)
1722 {
1723 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1724 	int shift = offset * 2;
1725 	int ret;
1726 
1727 	if (test_and_set_bit(offset, pdata->gchip_output))
1728 		return 0;
1729 
1730 	pm_runtime_get_sync(pdata->dev);
1731 
1732 	/* Set value first to avoid glitching */
1733 	ti_sn_bridge_gpio_set(chip, offset, val);
1734 
1735 	/* Set direction */
1736 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1737 				 SN_GPIO_MUX_MASK << shift,
1738 				 SN_GPIO_MUX_OUTPUT << shift);
1739 	if (ret) {
1740 		clear_bit(offset, pdata->gchip_output);
1741 		pm_runtime_put_autosuspend(pdata->dev);
1742 	}
1743 
1744 	return ret;
1745 }
1746 
1747 static int ti_sn_bridge_gpio_request(struct gpio_chip *chip, unsigned int offset)
1748 {
1749 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1750 
1751 	if (offset == SN_PWM_GPIO_IDX)
1752 		return ti_sn_pwm_pin_request(pdata);
1753 
1754 	return 0;
1755 }
1756 
1757 static void ti_sn_bridge_gpio_free(struct gpio_chip *chip, unsigned int offset)
1758 {
1759 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1760 
1761 	/* We won't keep pm_runtime if we're input, so switch there on free */
1762 	ti_sn_bridge_gpio_direction_input(chip, offset);
1763 
1764 	if (offset == SN_PWM_GPIO_IDX)
1765 		ti_sn_pwm_pin_release(pdata);
1766 }
1767 
1768 static const char * const ti_sn_bridge_gpio_names[SN_NUM_GPIOS] = {
1769 	"GPIO1", "GPIO2", "GPIO3", "GPIO4"
1770 };
1771 
1772 static int ti_sn_gpio_probe(struct auxiliary_device *adev,
1773 			    const struct auxiliary_device_id *id)
1774 {
1775 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1776 	int ret;
1777 
1778 	/* Only init if someone is going to use us as a GPIO controller */
1779 	if (!of_property_read_bool(pdata->dev->of_node, "gpio-controller"))
1780 		return 0;
1781 
1782 	pdata->gchip.label = dev_name(pdata->dev);
1783 	pdata->gchip.parent = pdata->dev;
1784 	pdata->gchip.owner = THIS_MODULE;
1785 	pdata->gchip.of_xlate = tn_sn_bridge_of_xlate;
1786 	pdata->gchip.of_gpio_n_cells = 2;
1787 	pdata->gchip.request = ti_sn_bridge_gpio_request;
1788 	pdata->gchip.free = ti_sn_bridge_gpio_free;
1789 	pdata->gchip.get_direction = ti_sn_bridge_gpio_get_direction;
1790 	pdata->gchip.direction_input = ti_sn_bridge_gpio_direction_input;
1791 	pdata->gchip.direction_output = ti_sn_bridge_gpio_direction_output;
1792 	pdata->gchip.get = ti_sn_bridge_gpio_get;
1793 	pdata->gchip.set = ti_sn_bridge_gpio_set;
1794 	pdata->gchip.can_sleep = true;
1795 	pdata->gchip.names = ti_sn_bridge_gpio_names;
1796 	pdata->gchip.ngpio = SN_NUM_GPIOS;
1797 	pdata->gchip.base = -1;
1798 	ret = devm_gpiochip_add_data(&adev->dev, &pdata->gchip, pdata);
1799 	if (ret)
1800 		dev_err(pdata->dev, "can't add gpio chip\n");
1801 
1802 	return ret;
1803 }
1804 
1805 static const struct auxiliary_device_id ti_sn_gpio_id_table[] = {
1806 	{ .name = "ti_sn65dsi86.gpio", },
1807 	{},
1808 };
1809 
1810 MODULE_DEVICE_TABLE(auxiliary, ti_sn_gpio_id_table);
1811 
1812 static struct auxiliary_driver ti_sn_gpio_driver = {
1813 	.name = "gpio",
1814 	.probe = ti_sn_gpio_probe,
1815 	.id_table = ti_sn_gpio_id_table,
1816 };
1817 
1818 static int __init ti_sn_gpio_register(void)
1819 {
1820 	return auxiliary_driver_register(&ti_sn_gpio_driver);
1821 }
1822 
1823 static void ti_sn_gpio_unregister(void)
1824 {
1825 	auxiliary_driver_unregister(&ti_sn_gpio_driver);
1826 }
1827 
1828 #else
1829 
1830 static inline int ti_sn_gpio_register(void) { return 0; }
1831 static inline void ti_sn_gpio_unregister(void) {}
1832 
1833 #endif
1834 
1835 /* -----------------------------------------------------------------------------
1836  * Probe & Remove
1837  */
1838 
1839 static void ti_sn65dsi86_runtime_disable(void *data)
1840 {
1841 	pm_runtime_dont_use_autosuspend(data);
1842 	pm_runtime_disable(data);
1843 }
1844 
1845 static int ti_sn65dsi86_parse_regulators(struct ti_sn65dsi86 *pdata)
1846 {
1847 	unsigned int i;
1848 	const char * const ti_sn_bridge_supply_names[] = {
1849 		"vcca", "vcc", "vccio", "vpll",
1850 	};
1851 
1852 	for (i = 0; i < SN_REGULATOR_SUPPLY_NUM; i++)
1853 		pdata->supplies[i].supply = ti_sn_bridge_supply_names[i];
1854 
1855 	return devm_regulator_bulk_get(pdata->dev, SN_REGULATOR_SUPPLY_NUM,
1856 				       pdata->supplies);
1857 }
1858 
1859 static int ti_sn65dsi86_probe(struct i2c_client *client)
1860 {
1861 	struct device *dev = &client->dev;
1862 	struct ti_sn65dsi86 *pdata;
1863 	int ret;
1864 
1865 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1866 		DRM_ERROR("device doesn't support I2C\n");
1867 		return -ENODEV;
1868 	}
1869 
1870 	pdata = devm_kzalloc(dev, sizeof(struct ti_sn65dsi86), GFP_KERNEL);
1871 	if (!pdata)
1872 		return -ENOMEM;
1873 	dev_set_drvdata(dev, pdata);
1874 	pdata->dev = dev;
1875 
1876 	mutex_init(&pdata->comms_mutex);
1877 
1878 	pdata->regmap = devm_regmap_init_i2c(client,
1879 					     &ti_sn65dsi86_regmap_config);
1880 	if (IS_ERR(pdata->regmap))
1881 		return dev_err_probe(dev, PTR_ERR(pdata->regmap),
1882 				     "regmap i2c init failed\n");
1883 
1884 	pdata->enable_gpio = devm_gpiod_get_optional(dev, "enable",
1885 						     GPIOD_OUT_LOW);
1886 	if (IS_ERR(pdata->enable_gpio))
1887 		return dev_err_probe(dev, PTR_ERR(pdata->enable_gpio),
1888 				     "failed to get enable gpio from DT\n");
1889 
1890 	ret = ti_sn65dsi86_parse_regulators(pdata);
1891 	if (ret)
1892 		return dev_err_probe(dev, ret, "failed to parse regulators\n");
1893 
1894 	pdata->refclk = devm_clk_get_optional(dev, "refclk");
1895 	if (IS_ERR(pdata->refclk))
1896 		return dev_err_probe(dev, PTR_ERR(pdata->refclk),
1897 				     "failed to get reference clock\n");
1898 
1899 	pm_runtime_enable(dev);
1900 	pm_runtime_set_autosuspend_delay(pdata->dev, 500);
1901 	pm_runtime_use_autosuspend(pdata->dev);
1902 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_runtime_disable, dev);
1903 	if (ret)
1904 		return ret;
1905 
1906 	ti_sn65dsi86_debugfs_init(pdata);
1907 
1908 	/*
1909 	 * Break ourselves up into a collection of aux devices. The only real
1910 	 * motiviation here is to solve the chicken-and-egg problem of probe
1911 	 * ordering. The bridge wants the panel to be there when it probes.
1912 	 * The panel wants its HPD GPIO (provided by sn65dsi86 on some boards)
1913 	 * when it probes. The panel and maybe backlight might want the DDC
1914 	 * bus or the pwm_chip. Having sub-devices allows the some sub devices
1915 	 * to finish probing even if others return -EPROBE_DEFER and gets us
1916 	 * around the problems.
1917 	 */
1918 
1919 	if (IS_ENABLED(CONFIG_OF_GPIO)) {
1920 		ret = ti_sn65dsi86_add_aux_device(pdata, &pdata->gpio_aux, "gpio");
1921 		if (ret)
1922 			return ret;
1923 	}
1924 
1925 	if (IS_ENABLED(CONFIG_PWM)) {
1926 		ret = ti_sn65dsi86_add_aux_device(pdata, &pdata->pwm_aux, "pwm");
1927 		if (ret)
1928 			return ret;
1929 	}
1930 
1931 	/*
1932 	 * NOTE: At the end of the AUX channel probe we'll add the aux device
1933 	 * for the bridge. This is because the bridge can't be used until the
1934 	 * AUX channel is there and this is a very simple solution to the
1935 	 * dependency problem.
1936 	 */
1937 	return ti_sn65dsi86_add_aux_device(pdata, &pdata->aux_aux, "aux");
1938 }
1939 
1940 static struct i2c_device_id ti_sn65dsi86_id[] = {
1941 	{ "ti,sn65dsi86", 0},
1942 	{},
1943 };
1944 MODULE_DEVICE_TABLE(i2c, ti_sn65dsi86_id);
1945 
1946 static const struct of_device_id ti_sn65dsi86_match_table[] = {
1947 	{.compatible = "ti,sn65dsi86"},
1948 	{},
1949 };
1950 MODULE_DEVICE_TABLE(of, ti_sn65dsi86_match_table);
1951 
1952 static struct i2c_driver ti_sn65dsi86_driver = {
1953 	.driver = {
1954 		.name = "ti_sn65dsi86",
1955 		.of_match_table = ti_sn65dsi86_match_table,
1956 		.pm = &ti_sn65dsi86_pm_ops,
1957 	},
1958 	.probe_new = ti_sn65dsi86_probe,
1959 	.id_table = ti_sn65dsi86_id,
1960 };
1961 
1962 static int __init ti_sn65dsi86_init(void)
1963 {
1964 	int ret;
1965 
1966 	ret = i2c_add_driver(&ti_sn65dsi86_driver);
1967 	if (ret)
1968 		return ret;
1969 
1970 	ret = ti_sn_gpio_register();
1971 	if (ret)
1972 		goto err_main_was_registered;
1973 
1974 	ret = ti_sn_pwm_register();
1975 	if (ret)
1976 		goto err_gpio_was_registered;
1977 
1978 	ret = auxiliary_driver_register(&ti_sn_aux_driver);
1979 	if (ret)
1980 		goto err_pwm_was_registered;
1981 
1982 	ret = auxiliary_driver_register(&ti_sn_bridge_driver);
1983 	if (ret)
1984 		goto err_aux_was_registered;
1985 
1986 	return 0;
1987 
1988 err_aux_was_registered:
1989 	auxiliary_driver_unregister(&ti_sn_aux_driver);
1990 err_pwm_was_registered:
1991 	ti_sn_pwm_unregister();
1992 err_gpio_was_registered:
1993 	ti_sn_gpio_unregister();
1994 err_main_was_registered:
1995 	i2c_del_driver(&ti_sn65dsi86_driver);
1996 
1997 	return ret;
1998 }
1999 module_init(ti_sn65dsi86_init);
2000 
2001 static void __exit ti_sn65dsi86_exit(void)
2002 {
2003 	auxiliary_driver_unregister(&ti_sn_bridge_driver);
2004 	auxiliary_driver_unregister(&ti_sn_aux_driver);
2005 	ti_sn_pwm_unregister();
2006 	ti_sn_gpio_unregister();
2007 	i2c_del_driver(&ti_sn65dsi86_driver);
2008 }
2009 module_exit(ti_sn65dsi86_exit);
2010 
2011 MODULE_AUTHOR("Sandeep Panda <spanda@codeaurora.org>");
2012 MODULE_DESCRIPTION("sn65dsi86 DSI to eDP bridge driver");
2013 MODULE_LICENSE("GPL v2");
2014