xref: /linux/drivers/gpu/drm/bridge/ti-sn65dsi86.c (revision 3d0fe49454652117522f60bfbefb978ba0e5300b)
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 static void ti_sn65dsi86_aux_device_release(struct device *dev)
472 {
473 	struct auxiliary_device *aux = container_of(dev, struct auxiliary_device, dev);
474 
475 	kfree(aux);
476 }
477 
478 static int ti_sn65dsi86_add_aux_device(struct ti_sn65dsi86 *pdata,
479 				       struct auxiliary_device **aux_out,
480 				       const char *name)
481 {
482 	struct device *dev = pdata->dev;
483 	struct auxiliary_device *aux;
484 	int ret;
485 
486 	aux = kzalloc(sizeof(*aux), GFP_KERNEL);
487 	if (!aux)
488 		return -ENOMEM;
489 
490 	aux->name = name;
491 	aux->dev.parent = dev;
492 	aux->dev.release = ti_sn65dsi86_aux_device_release;
493 	device_set_of_node_from_dev(&aux->dev, dev);
494 	ret = auxiliary_device_init(aux);
495 	if (ret) {
496 		kfree(aux);
497 		return ret;
498 	}
499 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_uninit_aux, aux);
500 	if (ret)
501 		return ret;
502 
503 	ret = auxiliary_device_add(aux);
504 	if (ret)
505 		return ret;
506 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_delete_aux, aux);
507 	if (!ret)
508 		*aux_out = aux;
509 
510 	return ret;
511 }
512 
513 /* -----------------------------------------------------------------------------
514  * AUX Adapter
515  */
516 
517 static struct ti_sn65dsi86 *aux_to_ti_sn65dsi86(struct drm_dp_aux *aux)
518 {
519 	return container_of(aux, struct ti_sn65dsi86, aux);
520 }
521 
522 static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux,
523 				  struct drm_dp_aux_msg *msg)
524 {
525 	struct ti_sn65dsi86 *pdata = aux_to_ti_sn65dsi86(aux);
526 	u32 request = msg->request & ~(DP_AUX_I2C_MOT | DP_AUX_I2C_WRITE_STATUS_UPDATE);
527 	u32 request_val = AUX_CMD_REQ(msg->request);
528 	u8 *buf = msg->buffer;
529 	unsigned int len = msg->size;
530 	unsigned int val;
531 	int ret;
532 	u8 addr_len[SN_AUX_LENGTH_REG + 1 - SN_AUX_ADDR_19_16_REG];
533 
534 	if (len > SN_AUX_MAX_PAYLOAD_BYTES)
535 		return -EINVAL;
536 
537 	pm_runtime_get_sync(pdata->dev);
538 	mutex_lock(&pdata->comms_mutex);
539 
540 	/*
541 	 * If someone tries to do a DDC over AUX transaction before pre_enable()
542 	 * on a device without a dedicated reference clock then we just can't
543 	 * do it. Fail right away. This prevents non-refclk users from reading
544 	 * the EDID before enabling the panel but such is life.
545 	 */
546 	if (!pdata->comms_enabled) {
547 		ret = -EIO;
548 		goto exit;
549 	}
550 
551 	switch (request) {
552 	case DP_AUX_NATIVE_WRITE:
553 	case DP_AUX_I2C_WRITE:
554 	case DP_AUX_NATIVE_READ:
555 	case DP_AUX_I2C_READ:
556 		regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val);
557 		/* Assume it's good */
558 		msg->reply = 0;
559 		break;
560 	default:
561 		ret = -EINVAL;
562 		goto exit;
563 	}
564 
565 	BUILD_BUG_ON(sizeof(addr_len) != sizeof(__be32));
566 	put_unaligned_be32((msg->address & SN_AUX_ADDR_MASK) << 8 | len,
567 			   addr_len);
568 	regmap_bulk_write(pdata->regmap, SN_AUX_ADDR_19_16_REG, addr_len,
569 			  ARRAY_SIZE(addr_len));
570 
571 	if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE)
572 		regmap_bulk_write(pdata->regmap, SN_AUX_WDATA_REG(0), buf, len);
573 
574 	/* Clear old status bits before start so we don't get confused */
575 	regmap_write(pdata->regmap, SN_AUX_CMD_STATUS_REG,
576 		     AUX_IRQ_STATUS_NAT_I2C_FAIL |
577 		     AUX_IRQ_STATUS_AUX_RPLY_TOUT |
578 		     AUX_IRQ_STATUS_AUX_SHORT);
579 
580 	regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val | AUX_CMD_SEND);
581 
582 	/* Zero delay loop because i2c transactions are slow already */
583 	ret = regmap_read_poll_timeout(pdata->regmap, SN_AUX_CMD_REG, val,
584 				       !(val & AUX_CMD_SEND), 0, 50 * 1000);
585 	if (ret)
586 		goto exit;
587 
588 	ret = regmap_read(pdata->regmap, SN_AUX_CMD_STATUS_REG, &val);
589 	if (ret)
590 		goto exit;
591 
592 	if (val & AUX_IRQ_STATUS_AUX_RPLY_TOUT) {
593 		/*
594 		 * The hardware tried the message seven times per the DP spec
595 		 * but it hit a timeout. We ignore defers here because they're
596 		 * handled in hardware.
597 		 */
598 		ret = -ETIMEDOUT;
599 		goto exit;
600 	}
601 
602 	if (val & AUX_IRQ_STATUS_AUX_SHORT) {
603 		ret = regmap_read(pdata->regmap, SN_AUX_LENGTH_REG, &len);
604 		if (ret)
605 			goto exit;
606 	} else if (val & AUX_IRQ_STATUS_NAT_I2C_FAIL) {
607 		switch (request) {
608 		case DP_AUX_I2C_WRITE:
609 		case DP_AUX_I2C_READ:
610 			msg->reply |= DP_AUX_I2C_REPLY_NACK;
611 			break;
612 		case DP_AUX_NATIVE_READ:
613 		case DP_AUX_NATIVE_WRITE:
614 			msg->reply |= DP_AUX_NATIVE_REPLY_NACK;
615 			break;
616 		}
617 		len = 0;
618 		goto exit;
619 	}
620 
621 	if (request != DP_AUX_NATIVE_WRITE && request != DP_AUX_I2C_WRITE && len != 0)
622 		ret = regmap_bulk_read(pdata->regmap, SN_AUX_RDATA_REG(0), buf, len);
623 
624 exit:
625 	mutex_unlock(&pdata->comms_mutex);
626 	pm_runtime_mark_last_busy(pdata->dev);
627 	pm_runtime_put_autosuspend(pdata->dev);
628 
629 	if (ret)
630 		return ret;
631 	return len;
632 }
633 
634 static int ti_sn_aux_wait_hpd_asserted(struct drm_dp_aux *aux, unsigned long wait_us)
635 {
636 	/*
637 	 * The HPD in this chip is a bit useless (See comment in
638 	 * ti_sn65dsi86_enable_comms) so if our driver is expected to wait
639 	 * for HPD, we just assume it's asserted after the wait_us delay.
640 	 *
641 	 * In case we are asked to wait forever (wait_us=0) take conservative
642 	 * 500ms delay.
643 	 */
644 	if (wait_us == 0)
645 		wait_us = 500000;
646 
647 	usleep_range(wait_us, wait_us + 1000);
648 
649 	return 0;
650 }
651 
652 static int ti_sn_aux_probe(struct auxiliary_device *adev,
653 			   const struct auxiliary_device_id *id)
654 {
655 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
656 	int ret;
657 
658 	pdata->aux.name = "ti-sn65dsi86-aux";
659 	pdata->aux.dev = &adev->dev;
660 	pdata->aux.transfer = ti_sn_aux_transfer;
661 	pdata->aux.wait_hpd_asserted = ti_sn_aux_wait_hpd_asserted;
662 	drm_dp_aux_init(&pdata->aux);
663 
664 	ret = devm_of_dp_aux_populate_ep_devices(&pdata->aux);
665 	if (ret)
666 		return ret;
667 
668 	/*
669 	 * The eDP to MIPI bridge parts don't work until the AUX channel is
670 	 * setup so we don't add it in the main driver probe, we add it now.
671 	 */
672 	return ti_sn65dsi86_add_aux_device(pdata, &pdata->bridge_aux, "bridge");
673 }
674 
675 static const struct auxiliary_device_id ti_sn_aux_id_table[] = {
676 	{ .name = "ti_sn65dsi86.aux", },
677 	{},
678 };
679 
680 static struct auxiliary_driver ti_sn_aux_driver = {
681 	.name = "aux",
682 	.probe = ti_sn_aux_probe,
683 	.id_table = ti_sn_aux_id_table,
684 };
685 
686 /*------------------------------------------------------------------------------
687  * DRM Bridge
688  */
689 
690 static struct ti_sn65dsi86 *bridge_to_ti_sn65dsi86(struct drm_bridge *bridge)
691 {
692 	return container_of(bridge, struct ti_sn65dsi86, bridge);
693 }
694 
695 static int ti_sn_attach_host(struct auxiliary_device *adev, struct ti_sn65dsi86 *pdata)
696 {
697 	int val;
698 	struct mipi_dsi_host *host;
699 	struct mipi_dsi_device *dsi;
700 	struct device *dev = pdata->dev;
701 	const struct mipi_dsi_device_info info = { .type = "ti_sn_bridge",
702 						   .channel = 0,
703 						   .node = NULL,
704 	};
705 
706 	host = of_find_mipi_dsi_host_by_node(pdata->host_node);
707 	if (!host)
708 		return -EPROBE_DEFER;
709 
710 	dsi = devm_mipi_dsi_device_register_full(&adev->dev, host, &info);
711 	if (IS_ERR(dsi))
712 		return PTR_ERR(dsi);
713 
714 	/* TODO: setting to 4 MIPI lanes always for now */
715 	dsi->lanes = 4;
716 	dsi->format = MIPI_DSI_FMT_RGB888;
717 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
718 
719 	/* check if continuous dsi clock is required or not */
720 	pm_runtime_get_sync(dev);
721 	regmap_read(pdata->regmap, SN_DPPLL_SRC_REG, &val);
722 	pm_runtime_put_autosuspend(dev);
723 	if (!(val & DPPLL_CLK_SRC_DSICLK))
724 		dsi->mode_flags |= MIPI_DSI_CLOCK_NON_CONTINUOUS;
725 
726 	pdata->dsi = dsi;
727 
728 	return devm_mipi_dsi_attach(&adev->dev, dsi);
729 }
730 
731 static int ti_sn_bridge_attach(struct drm_bridge *bridge,
732 			       enum drm_bridge_attach_flags flags)
733 {
734 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
735 	int ret;
736 
737 	pdata->aux.drm_dev = bridge->dev;
738 	ret = drm_dp_aux_register(&pdata->aux);
739 	if (ret < 0) {
740 		drm_err(bridge->dev, "Failed to register DP AUX channel: %d\n", ret);
741 		return ret;
742 	}
743 
744 	/*
745 	 * Attach the next bridge.
746 	 * We never want the next bridge to *also* create a connector.
747 	 */
748 	ret = drm_bridge_attach(bridge->encoder, pdata->next_bridge,
749 				&pdata->bridge, flags | DRM_BRIDGE_ATTACH_NO_CONNECTOR);
750 	if (ret < 0)
751 		goto err_initted_aux;
752 
753 	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
754 		return 0;
755 
756 	pdata->connector = drm_bridge_connector_init(pdata->bridge.dev,
757 						     pdata->bridge.encoder);
758 	if (IS_ERR(pdata->connector)) {
759 		ret = PTR_ERR(pdata->connector);
760 		goto err_initted_aux;
761 	}
762 
763 	drm_connector_attach_encoder(pdata->connector, pdata->bridge.encoder);
764 
765 	return 0;
766 
767 err_initted_aux:
768 	drm_dp_aux_unregister(&pdata->aux);
769 	return ret;
770 }
771 
772 static void ti_sn_bridge_detach(struct drm_bridge *bridge)
773 {
774 	drm_dp_aux_unregister(&bridge_to_ti_sn65dsi86(bridge)->aux);
775 }
776 
777 static enum drm_mode_status
778 ti_sn_bridge_mode_valid(struct drm_bridge *bridge,
779 			const struct drm_display_info *info,
780 			const struct drm_display_mode *mode)
781 {
782 	/* maximum supported resolution is 4K at 60 fps */
783 	if (mode->clock > 594000)
784 		return MODE_CLOCK_HIGH;
785 
786 	/*
787 	 * The front and back porch registers are 8 bits, and pulse width
788 	 * registers are 15 bits, so reject any modes with larger periods.
789 	 */
790 
791 	if ((mode->hsync_start - mode->hdisplay) > 0xff)
792 		return MODE_HBLANK_WIDE;
793 
794 	if ((mode->vsync_start - mode->vdisplay) > 0xff)
795 		return MODE_VBLANK_WIDE;
796 
797 	if ((mode->hsync_end - mode->hsync_start) > 0x7fff)
798 		return MODE_HSYNC_WIDE;
799 
800 	if ((mode->vsync_end - mode->vsync_start) > 0x7fff)
801 		return MODE_VSYNC_WIDE;
802 
803 	if ((mode->htotal - mode->hsync_end) > 0xff)
804 		return MODE_HBLANK_WIDE;
805 
806 	if ((mode->vtotal - mode->vsync_end) > 0xff)
807 		return MODE_VBLANK_WIDE;
808 
809 	return MODE_OK;
810 }
811 
812 static void ti_sn_bridge_atomic_disable(struct drm_bridge *bridge,
813 					struct drm_bridge_state *old_bridge_state)
814 {
815 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
816 
817 	/* disable video stream */
818 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE, 0);
819 }
820 
821 static void ti_sn_bridge_set_dsi_rate(struct ti_sn65dsi86 *pdata)
822 {
823 	unsigned int bit_rate_mhz, clk_freq_mhz;
824 	unsigned int val;
825 	struct drm_display_mode *mode =
826 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
827 
828 	/* set DSIA clk frequency */
829 	bit_rate_mhz = (mode->clock / 1000) *
830 			mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
831 	clk_freq_mhz = bit_rate_mhz / (pdata->dsi->lanes * 2);
832 
833 	/* for each increment in val, frequency increases by 5MHz */
834 	val = (MIN_DSI_CLK_FREQ_MHZ / 5) +
835 		(((clk_freq_mhz - MIN_DSI_CLK_FREQ_MHZ) / 5) & 0xFF);
836 	regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val);
837 }
838 
839 static unsigned int ti_sn_bridge_get_bpp(struct drm_connector *connector)
840 {
841 	if (connector->display_info.bpc <= 6)
842 		return 18;
843 	else
844 		return 24;
845 }
846 
847 /*
848  * LUT index corresponds to register value and
849  * LUT values corresponds to dp data rate supported
850  * by the bridge in Mbps unit.
851  */
852 static const unsigned int ti_sn_bridge_dp_rate_lut[] = {
853 	0, 1620, 2160, 2430, 2700, 3240, 4320, 5400
854 };
855 
856 static int ti_sn_bridge_calc_min_dp_rate_idx(struct ti_sn65dsi86 *pdata, unsigned int bpp)
857 {
858 	unsigned int bit_rate_khz, dp_rate_mhz;
859 	unsigned int i;
860 	struct drm_display_mode *mode =
861 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
862 
863 	/* Calculate minimum bit rate based on our pixel clock. */
864 	bit_rate_khz = mode->clock * bpp;
865 
866 	/* Calculate minimum DP data rate, taking 80% as per DP spec */
867 	dp_rate_mhz = DIV_ROUND_UP(bit_rate_khz * DP_CLK_FUDGE_NUM,
868 				   1000 * pdata->dp_lanes * DP_CLK_FUDGE_DEN);
869 
870 	for (i = 1; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++)
871 		if (ti_sn_bridge_dp_rate_lut[i] >= dp_rate_mhz)
872 			break;
873 
874 	return i;
875 }
876 
877 static unsigned int ti_sn_bridge_read_valid_rates(struct ti_sn65dsi86 *pdata)
878 {
879 	unsigned int valid_rates = 0;
880 	unsigned int rate_per_200khz;
881 	unsigned int rate_mhz;
882 	u8 dpcd_val;
883 	int ret;
884 	int i, j;
885 
886 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_EDP_DPCD_REV, &dpcd_val);
887 	if (ret != 1) {
888 		DRM_DEV_ERROR(pdata->dev,
889 			      "Can't read eDP rev (%d), assuming 1.1\n", ret);
890 		dpcd_val = DP_EDP_11;
891 	}
892 
893 	if (dpcd_val >= DP_EDP_14) {
894 		/* eDP 1.4 devices must provide a custom table */
895 		__le16 sink_rates[DP_MAX_SUPPORTED_RATES];
896 
897 		ret = drm_dp_dpcd_read(&pdata->aux, DP_SUPPORTED_LINK_RATES,
898 				       sink_rates, sizeof(sink_rates));
899 
900 		if (ret != sizeof(sink_rates)) {
901 			DRM_DEV_ERROR(pdata->dev,
902 				"Can't read supported rate table (%d)\n", ret);
903 
904 			/* By zeroing we'll fall back to DP_MAX_LINK_RATE. */
905 			memset(sink_rates, 0, sizeof(sink_rates));
906 		}
907 
908 		for (i = 0; i < ARRAY_SIZE(sink_rates); i++) {
909 			rate_per_200khz = le16_to_cpu(sink_rates[i]);
910 
911 			if (!rate_per_200khz)
912 				break;
913 
914 			rate_mhz = rate_per_200khz * 200 / 1000;
915 			for (j = 0;
916 			     j < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
917 			     j++) {
918 				if (ti_sn_bridge_dp_rate_lut[j] == rate_mhz)
919 					valid_rates |= BIT(j);
920 			}
921 		}
922 
923 		for (i = 0; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut); i++) {
924 			if (valid_rates & BIT(i))
925 				return valid_rates;
926 		}
927 		DRM_DEV_ERROR(pdata->dev,
928 			      "No matching eDP rates in table; falling back\n");
929 	}
930 
931 	/* On older versions best we can do is use DP_MAX_LINK_RATE */
932 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LINK_RATE, &dpcd_val);
933 	if (ret != 1) {
934 		DRM_DEV_ERROR(pdata->dev,
935 			      "Can't read max rate (%d); assuming 5.4 GHz\n",
936 			      ret);
937 		dpcd_val = DP_LINK_BW_5_4;
938 	}
939 
940 	switch (dpcd_val) {
941 	default:
942 		DRM_DEV_ERROR(pdata->dev,
943 			      "Unexpected max rate (%#x); assuming 5.4 GHz\n",
944 			      (int)dpcd_val);
945 		fallthrough;
946 	case DP_LINK_BW_5_4:
947 		valid_rates |= BIT(7);
948 		fallthrough;
949 	case DP_LINK_BW_2_7:
950 		valid_rates |= BIT(4);
951 		fallthrough;
952 	case DP_LINK_BW_1_62:
953 		valid_rates |= BIT(1);
954 		break;
955 	}
956 
957 	return valid_rates;
958 }
959 
960 static void ti_sn_bridge_set_video_timings(struct ti_sn65dsi86 *pdata)
961 {
962 	struct drm_display_mode *mode =
963 		&pdata->bridge.encoder->crtc->state->adjusted_mode;
964 	u8 hsync_polarity = 0, vsync_polarity = 0;
965 
966 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
967 		hsync_polarity = CHA_HSYNC_POLARITY;
968 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
969 		vsync_polarity = CHA_VSYNC_POLARITY;
970 
971 	ti_sn65dsi86_write_u16(pdata, SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG,
972 			       mode->hdisplay);
973 	ti_sn65dsi86_write_u16(pdata, SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG,
974 			       mode->vdisplay);
975 	regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG,
976 		     (mode->hsync_end - mode->hsync_start) & 0xFF);
977 	regmap_write(pdata->regmap, SN_CHA_HSYNC_PULSE_WIDTH_HIGH_REG,
978 		     (((mode->hsync_end - mode->hsync_start) >> 8) & 0x7F) |
979 		     hsync_polarity);
980 	regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG,
981 		     (mode->vsync_end - mode->vsync_start) & 0xFF);
982 	regmap_write(pdata->regmap, SN_CHA_VSYNC_PULSE_WIDTH_HIGH_REG,
983 		     (((mode->vsync_end - mode->vsync_start) >> 8) & 0x7F) |
984 		     vsync_polarity);
985 
986 	regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_BACK_PORCH_REG,
987 		     (mode->htotal - mode->hsync_end) & 0xFF);
988 	regmap_write(pdata->regmap, SN_CHA_VERTICAL_BACK_PORCH_REG,
989 		     (mode->vtotal - mode->vsync_end) & 0xFF);
990 
991 	regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_FRONT_PORCH_REG,
992 		     (mode->hsync_start - mode->hdisplay) & 0xFF);
993 	regmap_write(pdata->regmap, SN_CHA_VERTICAL_FRONT_PORCH_REG,
994 		     (mode->vsync_start - mode->vdisplay) & 0xFF);
995 
996 	usleep_range(10000, 10500); /* 10ms delay recommended by spec */
997 }
998 
999 static unsigned int ti_sn_get_max_lanes(struct ti_sn65dsi86 *pdata)
1000 {
1001 	u8 data;
1002 	int ret;
1003 
1004 	ret = drm_dp_dpcd_readb(&pdata->aux, DP_MAX_LANE_COUNT, &data);
1005 	if (ret != 1) {
1006 		DRM_DEV_ERROR(pdata->dev,
1007 			      "Can't read lane count (%d); assuming 4\n", ret);
1008 		return 4;
1009 	}
1010 
1011 	return data & DP_LANE_COUNT_MASK;
1012 }
1013 
1014 static int ti_sn_link_training(struct ti_sn65dsi86 *pdata, int dp_rate_idx,
1015 			       const char **last_err_str)
1016 {
1017 	unsigned int val;
1018 	int ret;
1019 	int i;
1020 
1021 	/* set dp clk frequency value */
1022 	regmap_update_bits(pdata->regmap, SN_DATARATE_CONFIG_REG,
1023 			   DP_DATARATE_MASK, DP_DATARATE(dp_rate_idx));
1024 
1025 	/* enable DP PLL */
1026 	regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
1027 
1028 	ret = regmap_read_poll_timeout(pdata->regmap, SN_DPPLL_SRC_REG, val,
1029 				       val & DPPLL_SRC_DP_PLL_LOCK, 1000,
1030 				       50 * 1000);
1031 	if (ret) {
1032 		*last_err_str = "DP_PLL_LOCK polling failed";
1033 		goto exit;
1034 	}
1035 
1036 	/*
1037 	 * We'll try to link train several times.  As part of link training
1038 	 * the bridge chip will write DP_SET_POWER_D0 to DP_SET_POWER.  If
1039 	 * the panel isn't ready quite it might respond NAK here which means
1040 	 * we need to try again.
1041 	 */
1042 	for (i = 0; i < SN_LINK_TRAINING_TRIES; i++) {
1043 		/* Semi auto link training mode */
1044 		regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A);
1045 		ret = regmap_read_poll_timeout(pdata->regmap, SN_ML_TX_MODE_REG, val,
1046 					       val == ML_TX_MAIN_LINK_OFF ||
1047 					       val == ML_TX_NORMAL_MODE, 1000,
1048 					       500 * 1000);
1049 		if (ret) {
1050 			*last_err_str = "Training complete polling failed";
1051 		} else if (val == ML_TX_MAIN_LINK_OFF) {
1052 			*last_err_str = "Link training failed, link is off";
1053 			ret = -EIO;
1054 			continue;
1055 		}
1056 
1057 		break;
1058 	}
1059 
1060 	/* If we saw quite a few retries, add a note about it */
1061 	if (!ret && i > SN_LINK_TRAINING_TRIES / 2)
1062 		DRM_DEV_INFO(pdata->dev, "Link training needed %d retries\n", i);
1063 
1064 exit:
1065 	/* Disable the PLL if we failed */
1066 	if (ret)
1067 		regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
1068 
1069 	return ret;
1070 }
1071 
1072 static void ti_sn_bridge_atomic_enable(struct drm_bridge *bridge,
1073 				       struct drm_bridge_state *old_bridge_state)
1074 {
1075 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1076 	struct drm_connector *connector;
1077 	const char *last_err_str = "No supported DP rate";
1078 	unsigned int valid_rates;
1079 	int dp_rate_idx;
1080 	unsigned int val;
1081 	int ret = -EINVAL;
1082 	int max_dp_lanes;
1083 	unsigned int bpp;
1084 
1085 	connector = drm_atomic_get_new_connector_for_encoder(old_bridge_state->base.state,
1086 							     bridge->encoder);
1087 	if (!connector) {
1088 		dev_err_ratelimited(pdata->dev, "Could not get the connector\n");
1089 		return;
1090 	}
1091 
1092 	max_dp_lanes = ti_sn_get_max_lanes(pdata);
1093 	pdata->dp_lanes = min(pdata->dp_lanes, max_dp_lanes);
1094 
1095 	/* DSI_A lane config */
1096 	val = CHA_DSI_LANES(SN_MAX_DP_LANES - pdata->dsi->lanes);
1097 	regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG,
1098 			   CHA_DSI_LANES_MASK, val);
1099 
1100 	regmap_write(pdata->regmap, SN_LN_ASSIGN_REG, pdata->ln_assign);
1101 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, LN_POLRS_MASK,
1102 			   pdata->ln_polrs << LN_POLRS_OFFSET);
1103 
1104 	/* set dsi clk frequency value */
1105 	ti_sn_bridge_set_dsi_rate(pdata);
1106 
1107 	/*
1108 	 * The SN65DSI86 only supports ASSR Display Authentication method and
1109 	 * this method is enabled for eDP panels. An eDP panel must support this
1110 	 * authentication method. We need to enable this method in the eDP panel
1111 	 * at DisplayPort address 0x0010A prior to link training.
1112 	 *
1113 	 * As only ASSR is supported by SN65DSI86, for full DisplayPort displays
1114 	 * we need to disable the scrambler.
1115 	 */
1116 	if (pdata->bridge.type == DRM_MODE_CONNECTOR_eDP) {
1117 		drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET,
1118 				   DP_ALTERNATE_SCRAMBLER_RESET_ENABLE);
1119 
1120 		regmap_update_bits(pdata->regmap, SN_TRAINING_SETTING_REG,
1121 				   SCRAMBLE_DISABLE, 0);
1122 	} else {
1123 		regmap_update_bits(pdata->regmap, SN_TRAINING_SETTING_REG,
1124 				   SCRAMBLE_DISABLE, SCRAMBLE_DISABLE);
1125 	}
1126 
1127 	bpp = ti_sn_bridge_get_bpp(connector);
1128 	/* Set the DP output format (18 bpp or 24 bpp) */
1129 	val = bpp == 18 ? BPP_18_RGB : 0;
1130 	regmap_update_bits(pdata->regmap, SN_DATA_FORMAT_REG, BPP_18_RGB, val);
1131 
1132 	/* DP lane config */
1133 	val = DP_NUM_LANES(min(pdata->dp_lanes, 3));
1134 	regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK,
1135 			   val);
1136 
1137 	valid_rates = ti_sn_bridge_read_valid_rates(pdata);
1138 
1139 	/* Train until we run out of rates */
1140 	for (dp_rate_idx = ti_sn_bridge_calc_min_dp_rate_idx(pdata, bpp);
1141 	     dp_rate_idx < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut);
1142 	     dp_rate_idx++) {
1143 		if (!(valid_rates & BIT(dp_rate_idx)))
1144 			continue;
1145 
1146 		ret = ti_sn_link_training(pdata, dp_rate_idx, &last_err_str);
1147 		if (!ret)
1148 			break;
1149 	}
1150 	if (ret) {
1151 		DRM_DEV_ERROR(pdata->dev, "%s (%d)\n", last_err_str, ret);
1152 		return;
1153 	}
1154 
1155 	/* config video parameters */
1156 	ti_sn_bridge_set_video_timings(pdata);
1157 
1158 	/* enable video stream */
1159 	regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG, VSTREAM_ENABLE,
1160 			   VSTREAM_ENABLE);
1161 }
1162 
1163 static void ti_sn_bridge_atomic_pre_enable(struct drm_bridge *bridge,
1164 					   struct drm_bridge_state *old_bridge_state)
1165 {
1166 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1167 
1168 	pm_runtime_get_sync(pdata->dev);
1169 
1170 	if (!pdata->refclk)
1171 		ti_sn65dsi86_enable_comms(pdata);
1172 
1173 	/* td7: min 100 us after enable before DSI data */
1174 	usleep_range(100, 110);
1175 }
1176 
1177 static void ti_sn_bridge_atomic_post_disable(struct drm_bridge *bridge,
1178 					     struct drm_bridge_state *old_bridge_state)
1179 {
1180 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1181 
1182 	/* semi auto link training mode OFF */
1183 	regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0);
1184 	/* Num lanes to 0 as per power sequencing in data sheet */
1185 	regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG, DP_NUM_LANES_MASK, 0);
1186 	/* disable DP PLL */
1187 	regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
1188 
1189 	if (!pdata->refclk)
1190 		ti_sn65dsi86_disable_comms(pdata);
1191 
1192 	pm_runtime_put_sync(pdata->dev);
1193 }
1194 
1195 static enum drm_connector_status ti_sn_bridge_detect(struct drm_bridge *bridge)
1196 {
1197 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1198 	int val = 0;
1199 
1200 	pm_runtime_get_sync(pdata->dev);
1201 	regmap_read(pdata->regmap, SN_HPD_DISABLE_REG, &val);
1202 	pm_runtime_put_autosuspend(pdata->dev);
1203 
1204 	return val & HPD_DEBOUNCED_STATE ? connector_status_connected
1205 					 : connector_status_disconnected;
1206 }
1207 
1208 static struct edid *ti_sn_bridge_get_edid(struct drm_bridge *bridge,
1209 					  struct drm_connector *connector)
1210 {
1211 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
1212 
1213 	return drm_get_edid(connector, &pdata->aux.ddc);
1214 }
1215 
1216 static const struct drm_bridge_funcs ti_sn_bridge_funcs = {
1217 	.attach = ti_sn_bridge_attach,
1218 	.detach = ti_sn_bridge_detach,
1219 	.mode_valid = ti_sn_bridge_mode_valid,
1220 	.get_edid = ti_sn_bridge_get_edid,
1221 	.detect = ti_sn_bridge_detect,
1222 	.atomic_pre_enable = ti_sn_bridge_atomic_pre_enable,
1223 	.atomic_enable = ti_sn_bridge_atomic_enable,
1224 	.atomic_disable = ti_sn_bridge_atomic_disable,
1225 	.atomic_post_disable = ti_sn_bridge_atomic_post_disable,
1226 	.atomic_reset = drm_atomic_helper_bridge_reset,
1227 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
1228 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
1229 };
1230 
1231 static void ti_sn_bridge_parse_lanes(struct ti_sn65dsi86 *pdata,
1232 				     struct device_node *np)
1233 {
1234 	u32 lane_assignments[SN_MAX_DP_LANES] = { 0, 1, 2, 3 };
1235 	u32 lane_polarities[SN_MAX_DP_LANES] = { };
1236 	struct device_node *endpoint;
1237 	u8 ln_assign = 0;
1238 	u8 ln_polrs = 0;
1239 	int dp_lanes;
1240 	int i;
1241 
1242 	/*
1243 	 * Read config from the device tree about lane remapping and lane
1244 	 * polarities.  These are optional and we assume identity map and
1245 	 * normal polarity if nothing is specified.  It's OK to specify just
1246 	 * data-lanes but not lane-polarities but not vice versa.
1247 	 *
1248 	 * Error checking is light (we just make sure we don't crash or
1249 	 * buffer overrun) and we assume dts is well formed and specifying
1250 	 * mappings that the hardware supports.
1251 	 */
1252 	endpoint = of_graph_get_endpoint_by_regs(np, 1, -1);
1253 	dp_lanes = drm_of_get_data_lanes_count(endpoint, 1, SN_MAX_DP_LANES);
1254 	if (dp_lanes > 0) {
1255 		of_property_read_u32_array(endpoint, "data-lanes",
1256 					   lane_assignments, dp_lanes);
1257 		of_property_read_u32_array(endpoint, "lane-polarities",
1258 					   lane_polarities, dp_lanes);
1259 	} else {
1260 		dp_lanes = SN_MAX_DP_LANES;
1261 	}
1262 	of_node_put(endpoint);
1263 
1264 	/*
1265 	 * Convert into register format.  Loop over all lanes even if
1266 	 * data-lanes had fewer elements so that we nicely initialize
1267 	 * the LN_ASSIGN register.
1268 	 */
1269 	for (i = SN_MAX_DP_LANES - 1; i >= 0; i--) {
1270 		ln_assign = ln_assign << LN_ASSIGN_WIDTH | lane_assignments[i];
1271 		ln_polrs = ln_polrs << 1 | lane_polarities[i];
1272 	}
1273 
1274 	/* Stash in our struct for when we power on */
1275 	pdata->dp_lanes = dp_lanes;
1276 	pdata->ln_assign = ln_assign;
1277 	pdata->ln_polrs = ln_polrs;
1278 }
1279 
1280 static int ti_sn_bridge_parse_dsi_host(struct ti_sn65dsi86 *pdata)
1281 {
1282 	struct device_node *np = pdata->dev->of_node;
1283 
1284 	pdata->host_node = of_graph_get_remote_node(np, 0, 0);
1285 
1286 	if (!pdata->host_node) {
1287 		DRM_ERROR("remote dsi host node not found\n");
1288 		return -ENODEV;
1289 	}
1290 
1291 	return 0;
1292 }
1293 
1294 static int ti_sn_bridge_probe(struct auxiliary_device *adev,
1295 			      const struct auxiliary_device_id *id)
1296 {
1297 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1298 	struct device_node *np = pdata->dev->of_node;
1299 	int ret;
1300 
1301 	pdata->next_bridge = devm_drm_of_get_bridge(&adev->dev, np, 1, 0);
1302 	if (IS_ERR(pdata->next_bridge))
1303 		return dev_err_probe(&adev->dev, PTR_ERR(pdata->next_bridge),
1304 				     "failed to create panel bridge\n");
1305 
1306 	ti_sn_bridge_parse_lanes(pdata, np);
1307 
1308 	ret = ti_sn_bridge_parse_dsi_host(pdata);
1309 	if (ret)
1310 		return ret;
1311 
1312 	pdata->bridge.funcs = &ti_sn_bridge_funcs;
1313 	pdata->bridge.of_node = np;
1314 	pdata->bridge.type = pdata->next_bridge->type == DRM_MODE_CONNECTOR_DisplayPort
1315 			   ? DRM_MODE_CONNECTOR_DisplayPort : DRM_MODE_CONNECTOR_eDP;
1316 
1317 	if (pdata->bridge.type == DRM_MODE_CONNECTOR_DisplayPort)
1318 		pdata->bridge.ops = DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_DETECT;
1319 
1320 	drm_bridge_add(&pdata->bridge);
1321 
1322 	ret = ti_sn_attach_host(adev, pdata);
1323 	if (ret) {
1324 		dev_err_probe(&adev->dev, ret, "failed to attach dsi host\n");
1325 		goto err_remove_bridge;
1326 	}
1327 
1328 	return 0;
1329 
1330 err_remove_bridge:
1331 	drm_bridge_remove(&pdata->bridge);
1332 	return ret;
1333 }
1334 
1335 static void ti_sn_bridge_remove(struct auxiliary_device *adev)
1336 {
1337 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1338 
1339 	if (!pdata)
1340 		return;
1341 
1342 	drm_bridge_remove(&pdata->bridge);
1343 
1344 	of_node_put(pdata->host_node);
1345 }
1346 
1347 static const struct auxiliary_device_id ti_sn_bridge_id_table[] = {
1348 	{ .name = "ti_sn65dsi86.bridge", },
1349 	{},
1350 };
1351 
1352 static struct auxiliary_driver ti_sn_bridge_driver = {
1353 	.name = "bridge",
1354 	.probe = ti_sn_bridge_probe,
1355 	.remove = ti_sn_bridge_remove,
1356 	.id_table = ti_sn_bridge_id_table,
1357 };
1358 
1359 /* -----------------------------------------------------------------------------
1360  * PWM Controller
1361  */
1362 #if defined(CONFIG_PWM)
1363 static int ti_sn_pwm_pin_request(struct ti_sn65dsi86 *pdata)
1364 {
1365 	return atomic_xchg(&pdata->pwm_pin_busy, 1) ? -EBUSY : 0;
1366 }
1367 
1368 static void ti_sn_pwm_pin_release(struct ti_sn65dsi86 *pdata)
1369 {
1370 	atomic_set(&pdata->pwm_pin_busy, 0);
1371 }
1372 
1373 static struct ti_sn65dsi86 *pwm_chip_to_ti_sn_bridge(struct pwm_chip *chip)
1374 {
1375 	return container_of(chip, struct ti_sn65dsi86, pchip);
1376 }
1377 
1378 static int ti_sn_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
1379 {
1380 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1381 
1382 	return ti_sn_pwm_pin_request(pdata);
1383 }
1384 
1385 static void ti_sn_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
1386 {
1387 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1388 
1389 	ti_sn_pwm_pin_release(pdata);
1390 }
1391 
1392 /*
1393  * Limitations:
1394  * - The PWM signal is not driven when the chip is powered down, or in its
1395  *   reset state and the driver does not implement the "suspend state"
1396  *   described in the documentation. In order to save power, state->enabled is
1397  *   interpreted as denoting if the signal is expected to be valid, and is used
1398  *   to determine if the chip needs to be kept powered.
1399  * - Changing both period and duty_cycle is not done atomically, neither is the
1400  *   multi-byte register updates, so the output might briefly be undefined
1401  *   during update.
1402  */
1403 static int ti_sn_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
1404 			   const struct pwm_state *state)
1405 {
1406 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1407 	unsigned int pwm_en_inv;
1408 	unsigned int backlight;
1409 	unsigned int pre_div;
1410 	unsigned int scale;
1411 	u64 period_max;
1412 	u64 period;
1413 	int ret;
1414 
1415 	if (!pdata->pwm_enabled) {
1416 		ret = pm_runtime_get_sync(pdata->dev);
1417 		if (ret < 0) {
1418 			pm_runtime_put_sync(pdata->dev);
1419 			return ret;
1420 		}
1421 	}
1422 
1423 	if (state->enabled) {
1424 		if (!pdata->pwm_enabled) {
1425 			/*
1426 			 * The chip might have been powered down while we
1427 			 * didn't hold a PM runtime reference, so mux in the
1428 			 * PWM function on the GPIO pin again.
1429 			 */
1430 			ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1431 						 SN_GPIO_MUX_MASK << (2 * SN_PWM_GPIO_IDX),
1432 						 SN_GPIO_MUX_SPECIAL << (2 * SN_PWM_GPIO_IDX));
1433 			if (ret) {
1434 				dev_err(pdata->dev, "failed to mux in PWM function\n");
1435 				goto out;
1436 			}
1437 		}
1438 
1439 		/*
1440 		 * Per the datasheet the PWM frequency is given by:
1441 		 *
1442 		 *                          REFCLK_FREQ
1443 		 *   PWM_FREQ = -----------------------------------
1444 		 *               PWM_PRE_DIV * BACKLIGHT_SCALE + 1
1445 		 *
1446 		 * However, after careful review the author is convinced that
1447 		 * the documentation has lost some parenthesis around
1448 		 * "BACKLIGHT_SCALE + 1".
1449 		 *
1450 		 * With the period T_pwm = 1/PWM_FREQ this can be written:
1451 		 *
1452 		 *   T_pwm * REFCLK_FREQ = PWM_PRE_DIV * (BACKLIGHT_SCALE + 1)
1453 		 *
1454 		 * In order to keep BACKLIGHT_SCALE within its 16 bits,
1455 		 * PWM_PRE_DIV must be:
1456 		 *
1457 		 *                     T_pwm * REFCLK_FREQ
1458 		 *   PWM_PRE_DIV >= -------------------------
1459 		 *                   BACKLIGHT_SCALE_MAX + 1
1460 		 *
1461 		 * To simplify the search and to favour higher resolution of
1462 		 * the duty cycle over accuracy of the period, the lowest
1463 		 * possible PWM_PRE_DIV is used. Finally the scale is
1464 		 * calculated as:
1465 		 *
1466 		 *                      T_pwm * REFCLK_FREQ
1467 		 *   BACKLIGHT_SCALE = ---------------------- - 1
1468 		 *                          PWM_PRE_DIV
1469 		 *
1470 		 * Here T_pwm is represented in seconds, so appropriate scaling
1471 		 * to nanoseconds is necessary.
1472 		 */
1473 
1474 		/* Minimum T_pwm is 1 / REFCLK_FREQ */
1475 		if (state->period <= NSEC_PER_SEC / pdata->pwm_refclk_freq) {
1476 			ret = -EINVAL;
1477 			goto out;
1478 		}
1479 
1480 		/*
1481 		 * Maximum T_pwm is 255 * (65535 + 1) / REFCLK_FREQ
1482 		 * Limit period to this to avoid overflows
1483 		 */
1484 		period_max = div_u64((u64)NSEC_PER_SEC * 255 * (65535 + 1),
1485 				     pdata->pwm_refclk_freq);
1486 		period = min(state->period, period_max);
1487 
1488 		pre_div = DIV64_U64_ROUND_UP(period * pdata->pwm_refclk_freq,
1489 					     (u64)NSEC_PER_SEC * (BACKLIGHT_SCALE_MAX + 1));
1490 		scale = div64_u64(period * pdata->pwm_refclk_freq, (u64)NSEC_PER_SEC * pre_div) - 1;
1491 
1492 		/*
1493 		 * The documentation has the duty ratio given as:
1494 		 *
1495 		 *     duty          BACKLIGHT
1496 		 *   ------- = ---------------------
1497 		 *    period    BACKLIGHT_SCALE + 1
1498 		 *
1499 		 * Solve for BACKLIGHT, substituting BACKLIGHT_SCALE according
1500 		 * to definition above and adjusting for nanosecond
1501 		 * representation of duty cycle gives us:
1502 		 */
1503 		backlight = div64_u64(state->duty_cycle * pdata->pwm_refclk_freq,
1504 				      (u64)NSEC_PER_SEC * pre_div);
1505 		if (backlight > scale)
1506 			backlight = scale;
1507 
1508 		ret = regmap_write(pdata->regmap, SN_PWM_PRE_DIV_REG, pre_div);
1509 		if (ret) {
1510 			dev_err(pdata->dev, "failed to update PWM_PRE_DIV\n");
1511 			goto out;
1512 		}
1513 
1514 		ti_sn65dsi86_write_u16(pdata, SN_BACKLIGHT_SCALE_REG, scale);
1515 		ti_sn65dsi86_write_u16(pdata, SN_BACKLIGHT_REG, backlight);
1516 	}
1517 
1518 	pwm_en_inv = FIELD_PREP(SN_PWM_EN_MASK, state->enabled) |
1519 		     FIELD_PREP(SN_PWM_INV_MASK, state->polarity == PWM_POLARITY_INVERSED);
1520 	ret = regmap_write(pdata->regmap, SN_PWM_EN_INV_REG, pwm_en_inv);
1521 	if (ret) {
1522 		dev_err(pdata->dev, "failed to update PWM_EN/PWM_INV\n");
1523 		goto out;
1524 	}
1525 
1526 	pdata->pwm_enabled = state->enabled;
1527 out:
1528 
1529 	if (!pdata->pwm_enabled)
1530 		pm_runtime_put_sync(pdata->dev);
1531 
1532 	return ret;
1533 }
1534 
1535 static int ti_sn_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
1536 			       struct pwm_state *state)
1537 {
1538 	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
1539 	unsigned int pwm_en_inv;
1540 	unsigned int pre_div;
1541 	u16 backlight;
1542 	u16 scale;
1543 	int ret;
1544 
1545 	ret = regmap_read(pdata->regmap, SN_PWM_EN_INV_REG, &pwm_en_inv);
1546 	if (ret)
1547 		return ret;
1548 
1549 	ret = ti_sn65dsi86_read_u16(pdata, SN_BACKLIGHT_SCALE_REG, &scale);
1550 	if (ret)
1551 		return ret;
1552 
1553 	ret = ti_sn65dsi86_read_u16(pdata, SN_BACKLIGHT_REG, &backlight);
1554 	if (ret)
1555 		return ret;
1556 
1557 	ret = regmap_read(pdata->regmap, SN_PWM_PRE_DIV_REG, &pre_div);
1558 	if (ret)
1559 		return ret;
1560 
1561 	state->enabled = FIELD_GET(SN_PWM_EN_MASK, pwm_en_inv);
1562 	if (FIELD_GET(SN_PWM_INV_MASK, pwm_en_inv))
1563 		state->polarity = PWM_POLARITY_INVERSED;
1564 	else
1565 		state->polarity = PWM_POLARITY_NORMAL;
1566 
1567 	state->period = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * pre_div * (scale + 1),
1568 					 pdata->pwm_refclk_freq);
1569 	state->duty_cycle = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * pre_div * backlight,
1570 					     pdata->pwm_refclk_freq);
1571 
1572 	if (state->duty_cycle > state->period)
1573 		state->duty_cycle = state->period;
1574 
1575 	return 0;
1576 }
1577 
1578 static const struct pwm_ops ti_sn_pwm_ops = {
1579 	.request = ti_sn_pwm_request,
1580 	.free = ti_sn_pwm_free,
1581 	.apply = ti_sn_pwm_apply,
1582 	.get_state = ti_sn_pwm_get_state,
1583 };
1584 
1585 static int ti_sn_pwm_probe(struct auxiliary_device *adev,
1586 			   const struct auxiliary_device_id *id)
1587 {
1588 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1589 
1590 	pdata->pchip.dev = pdata->dev;
1591 	pdata->pchip.ops = &ti_sn_pwm_ops;
1592 	pdata->pchip.npwm = 1;
1593 	pdata->pchip.of_xlate = of_pwm_single_xlate;
1594 	pdata->pchip.of_pwm_n_cells = 1;
1595 
1596 	return pwmchip_add(&pdata->pchip);
1597 }
1598 
1599 static void ti_sn_pwm_remove(struct auxiliary_device *adev)
1600 {
1601 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1602 
1603 	pwmchip_remove(&pdata->pchip);
1604 
1605 	if (pdata->pwm_enabled)
1606 		pm_runtime_put_sync(pdata->dev);
1607 }
1608 
1609 static const struct auxiliary_device_id ti_sn_pwm_id_table[] = {
1610 	{ .name = "ti_sn65dsi86.pwm", },
1611 	{},
1612 };
1613 
1614 static struct auxiliary_driver ti_sn_pwm_driver = {
1615 	.name = "pwm",
1616 	.probe = ti_sn_pwm_probe,
1617 	.remove = ti_sn_pwm_remove,
1618 	.id_table = ti_sn_pwm_id_table,
1619 };
1620 
1621 static int __init ti_sn_pwm_register(void)
1622 {
1623 	return auxiliary_driver_register(&ti_sn_pwm_driver);
1624 }
1625 
1626 static void ti_sn_pwm_unregister(void)
1627 {
1628 	auxiliary_driver_unregister(&ti_sn_pwm_driver);
1629 }
1630 
1631 #else
1632 static inline int ti_sn_pwm_pin_request(struct ti_sn65dsi86 *pdata) { return 0; }
1633 static inline void ti_sn_pwm_pin_release(struct ti_sn65dsi86 *pdata) {}
1634 
1635 static inline int ti_sn_pwm_register(void) { return 0; }
1636 static inline void ti_sn_pwm_unregister(void) {}
1637 #endif
1638 
1639 /* -----------------------------------------------------------------------------
1640  * GPIO Controller
1641  */
1642 #if defined(CONFIG_OF_GPIO)
1643 
1644 static int tn_sn_bridge_of_xlate(struct gpio_chip *chip,
1645 				 const struct of_phandle_args *gpiospec,
1646 				 u32 *flags)
1647 {
1648 	if (WARN_ON(gpiospec->args_count < chip->of_gpio_n_cells))
1649 		return -EINVAL;
1650 
1651 	if (gpiospec->args[0] > chip->ngpio || gpiospec->args[0] < 1)
1652 		return -EINVAL;
1653 
1654 	if (flags)
1655 		*flags = gpiospec->args[1];
1656 
1657 	return gpiospec->args[0] - SN_GPIO_PHYSICAL_OFFSET;
1658 }
1659 
1660 static int ti_sn_bridge_gpio_get_direction(struct gpio_chip *chip,
1661 					   unsigned int offset)
1662 {
1663 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1664 
1665 	/*
1666 	 * We already have to keep track of the direction because we use
1667 	 * that to figure out whether we've powered the device.  We can
1668 	 * just return that rather than (maybe) powering up the device
1669 	 * to ask its direction.
1670 	 */
1671 	return test_bit(offset, pdata->gchip_output) ?
1672 		GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
1673 }
1674 
1675 static int ti_sn_bridge_gpio_get(struct gpio_chip *chip, unsigned int offset)
1676 {
1677 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1678 	unsigned int val;
1679 	int ret;
1680 
1681 	/*
1682 	 * When the pin is an input we don't forcibly keep the bridge
1683 	 * powered--we just power it on to read the pin.  NOTE: part of
1684 	 * the reason this works is that the bridge defaults (when
1685 	 * powered back on) to all 4 GPIOs being configured as GPIO input.
1686 	 * Also note that if something else is keeping the chip powered the
1687 	 * pm_runtime functions are lightweight increments of a refcount.
1688 	 */
1689 	pm_runtime_get_sync(pdata->dev);
1690 	ret = regmap_read(pdata->regmap, SN_GPIO_IO_REG, &val);
1691 	pm_runtime_put_autosuspend(pdata->dev);
1692 
1693 	if (ret)
1694 		return ret;
1695 
1696 	return !!(val & BIT(SN_GPIO_INPUT_SHIFT + offset));
1697 }
1698 
1699 static void ti_sn_bridge_gpio_set(struct gpio_chip *chip, unsigned int offset,
1700 				  int val)
1701 {
1702 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1703 	int ret;
1704 
1705 	if (!test_bit(offset, pdata->gchip_output)) {
1706 		dev_err(pdata->dev, "Ignoring GPIO set while input\n");
1707 		return;
1708 	}
1709 
1710 	val &= 1;
1711 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_IO_REG,
1712 				 BIT(SN_GPIO_OUTPUT_SHIFT + offset),
1713 				 val << (SN_GPIO_OUTPUT_SHIFT + offset));
1714 	if (ret)
1715 		dev_warn(pdata->dev,
1716 			 "Failed to set bridge GPIO %u: %d\n", offset, ret);
1717 }
1718 
1719 static int ti_sn_bridge_gpio_direction_input(struct gpio_chip *chip,
1720 					     unsigned int offset)
1721 {
1722 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1723 	int shift = offset * 2;
1724 	int ret;
1725 
1726 	if (!test_and_clear_bit(offset, pdata->gchip_output))
1727 		return 0;
1728 
1729 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1730 				 SN_GPIO_MUX_MASK << shift,
1731 				 SN_GPIO_MUX_INPUT << shift);
1732 	if (ret) {
1733 		set_bit(offset, pdata->gchip_output);
1734 		return ret;
1735 	}
1736 
1737 	/*
1738 	 * NOTE: if nobody else is powering the device this may fully power
1739 	 * it off and when it comes back it will have lost all state, but
1740 	 * that's OK because the default is input and we're now an input.
1741 	 */
1742 	pm_runtime_put_autosuspend(pdata->dev);
1743 
1744 	return 0;
1745 }
1746 
1747 static int ti_sn_bridge_gpio_direction_output(struct gpio_chip *chip,
1748 					      unsigned int offset, int val)
1749 {
1750 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1751 	int shift = offset * 2;
1752 	int ret;
1753 
1754 	if (test_and_set_bit(offset, pdata->gchip_output))
1755 		return 0;
1756 
1757 	pm_runtime_get_sync(pdata->dev);
1758 
1759 	/* Set value first to avoid glitching */
1760 	ti_sn_bridge_gpio_set(chip, offset, val);
1761 
1762 	/* Set direction */
1763 	ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
1764 				 SN_GPIO_MUX_MASK << shift,
1765 				 SN_GPIO_MUX_OUTPUT << shift);
1766 	if (ret) {
1767 		clear_bit(offset, pdata->gchip_output);
1768 		pm_runtime_put_autosuspend(pdata->dev);
1769 	}
1770 
1771 	return ret;
1772 }
1773 
1774 static int ti_sn_bridge_gpio_request(struct gpio_chip *chip, unsigned int offset)
1775 {
1776 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1777 
1778 	if (offset == SN_PWM_GPIO_IDX)
1779 		return ti_sn_pwm_pin_request(pdata);
1780 
1781 	return 0;
1782 }
1783 
1784 static void ti_sn_bridge_gpio_free(struct gpio_chip *chip, unsigned int offset)
1785 {
1786 	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
1787 
1788 	/* We won't keep pm_runtime if we're input, so switch there on free */
1789 	ti_sn_bridge_gpio_direction_input(chip, offset);
1790 
1791 	if (offset == SN_PWM_GPIO_IDX)
1792 		ti_sn_pwm_pin_release(pdata);
1793 }
1794 
1795 static const char * const ti_sn_bridge_gpio_names[SN_NUM_GPIOS] = {
1796 	"GPIO1", "GPIO2", "GPIO3", "GPIO4"
1797 };
1798 
1799 static int ti_sn_gpio_probe(struct auxiliary_device *adev,
1800 			    const struct auxiliary_device_id *id)
1801 {
1802 	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
1803 	int ret;
1804 
1805 	/* Only init if someone is going to use us as a GPIO controller */
1806 	if (!of_property_read_bool(pdata->dev->of_node, "gpio-controller"))
1807 		return 0;
1808 
1809 	pdata->gchip.label = dev_name(pdata->dev);
1810 	pdata->gchip.parent = pdata->dev;
1811 	pdata->gchip.owner = THIS_MODULE;
1812 	pdata->gchip.of_xlate = tn_sn_bridge_of_xlate;
1813 	pdata->gchip.of_gpio_n_cells = 2;
1814 	pdata->gchip.request = ti_sn_bridge_gpio_request;
1815 	pdata->gchip.free = ti_sn_bridge_gpio_free;
1816 	pdata->gchip.get_direction = ti_sn_bridge_gpio_get_direction;
1817 	pdata->gchip.direction_input = ti_sn_bridge_gpio_direction_input;
1818 	pdata->gchip.direction_output = ti_sn_bridge_gpio_direction_output;
1819 	pdata->gchip.get = ti_sn_bridge_gpio_get;
1820 	pdata->gchip.set = ti_sn_bridge_gpio_set;
1821 	pdata->gchip.can_sleep = true;
1822 	pdata->gchip.names = ti_sn_bridge_gpio_names;
1823 	pdata->gchip.ngpio = SN_NUM_GPIOS;
1824 	pdata->gchip.base = -1;
1825 	ret = devm_gpiochip_add_data(&adev->dev, &pdata->gchip, pdata);
1826 	if (ret)
1827 		dev_err(pdata->dev, "can't add gpio chip\n");
1828 
1829 	return ret;
1830 }
1831 
1832 static const struct auxiliary_device_id ti_sn_gpio_id_table[] = {
1833 	{ .name = "ti_sn65dsi86.gpio", },
1834 	{},
1835 };
1836 
1837 MODULE_DEVICE_TABLE(auxiliary, ti_sn_gpio_id_table);
1838 
1839 static struct auxiliary_driver ti_sn_gpio_driver = {
1840 	.name = "gpio",
1841 	.probe = ti_sn_gpio_probe,
1842 	.id_table = ti_sn_gpio_id_table,
1843 };
1844 
1845 static int __init ti_sn_gpio_register(void)
1846 {
1847 	return auxiliary_driver_register(&ti_sn_gpio_driver);
1848 }
1849 
1850 static void ti_sn_gpio_unregister(void)
1851 {
1852 	auxiliary_driver_unregister(&ti_sn_gpio_driver);
1853 }
1854 
1855 #else
1856 
1857 static inline int ti_sn_gpio_register(void) { return 0; }
1858 static inline void ti_sn_gpio_unregister(void) {}
1859 
1860 #endif
1861 
1862 /* -----------------------------------------------------------------------------
1863  * Probe & Remove
1864  */
1865 
1866 static void ti_sn65dsi86_runtime_disable(void *data)
1867 {
1868 	pm_runtime_dont_use_autosuspend(data);
1869 	pm_runtime_disable(data);
1870 }
1871 
1872 static int ti_sn65dsi86_parse_regulators(struct ti_sn65dsi86 *pdata)
1873 {
1874 	unsigned int i;
1875 	const char * const ti_sn_bridge_supply_names[] = {
1876 		"vcca", "vcc", "vccio", "vpll",
1877 	};
1878 
1879 	for (i = 0; i < SN_REGULATOR_SUPPLY_NUM; i++)
1880 		pdata->supplies[i].supply = ti_sn_bridge_supply_names[i];
1881 
1882 	return devm_regulator_bulk_get(pdata->dev, SN_REGULATOR_SUPPLY_NUM,
1883 				       pdata->supplies);
1884 }
1885 
1886 static int ti_sn65dsi86_probe(struct i2c_client *client)
1887 {
1888 	struct device *dev = &client->dev;
1889 	struct ti_sn65dsi86 *pdata;
1890 	int ret;
1891 
1892 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1893 		DRM_ERROR("device doesn't support I2C\n");
1894 		return -ENODEV;
1895 	}
1896 
1897 	pdata = devm_kzalloc(dev, sizeof(struct ti_sn65dsi86), GFP_KERNEL);
1898 	if (!pdata)
1899 		return -ENOMEM;
1900 	dev_set_drvdata(dev, pdata);
1901 	pdata->dev = dev;
1902 
1903 	mutex_init(&pdata->comms_mutex);
1904 
1905 	pdata->regmap = devm_regmap_init_i2c(client,
1906 					     &ti_sn65dsi86_regmap_config);
1907 	if (IS_ERR(pdata->regmap))
1908 		return dev_err_probe(dev, PTR_ERR(pdata->regmap),
1909 				     "regmap i2c init failed\n");
1910 
1911 	pdata->enable_gpio = devm_gpiod_get_optional(dev, "enable",
1912 						     GPIOD_OUT_LOW);
1913 	if (IS_ERR(pdata->enable_gpio))
1914 		return dev_err_probe(dev, PTR_ERR(pdata->enable_gpio),
1915 				     "failed to get enable gpio from DT\n");
1916 
1917 	ret = ti_sn65dsi86_parse_regulators(pdata);
1918 	if (ret)
1919 		return dev_err_probe(dev, ret, "failed to parse regulators\n");
1920 
1921 	pdata->refclk = devm_clk_get_optional(dev, "refclk");
1922 	if (IS_ERR(pdata->refclk))
1923 		return dev_err_probe(dev, PTR_ERR(pdata->refclk),
1924 				     "failed to get reference clock\n");
1925 
1926 	pm_runtime_enable(dev);
1927 	pm_runtime_set_autosuspend_delay(pdata->dev, 500);
1928 	pm_runtime_use_autosuspend(pdata->dev);
1929 	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_runtime_disable, dev);
1930 	if (ret)
1931 		return ret;
1932 
1933 	ti_sn65dsi86_debugfs_init(pdata);
1934 
1935 	/*
1936 	 * Break ourselves up into a collection of aux devices. The only real
1937 	 * motiviation here is to solve the chicken-and-egg problem of probe
1938 	 * ordering. The bridge wants the panel to be there when it probes.
1939 	 * The panel wants its HPD GPIO (provided by sn65dsi86 on some boards)
1940 	 * when it probes. The panel and maybe backlight might want the DDC
1941 	 * bus or the pwm_chip. Having sub-devices allows the some sub devices
1942 	 * to finish probing even if others return -EPROBE_DEFER and gets us
1943 	 * around the problems.
1944 	 */
1945 
1946 	if (IS_ENABLED(CONFIG_OF_GPIO)) {
1947 		ret = ti_sn65dsi86_add_aux_device(pdata, &pdata->gpio_aux, "gpio");
1948 		if (ret)
1949 			return ret;
1950 	}
1951 
1952 	if (IS_ENABLED(CONFIG_PWM)) {
1953 		ret = ti_sn65dsi86_add_aux_device(pdata, &pdata->pwm_aux, "pwm");
1954 		if (ret)
1955 			return ret;
1956 	}
1957 
1958 	/*
1959 	 * NOTE: At the end of the AUX channel probe we'll add the aux device
1960 	 * for the bridge. This is because the bridge can't be used until the
1961 	 * AUX channel is there and this is a very simple solution to the
1962 	 * dependency problem.
1963 	 */
1964 	return ti_sn65dsi86_add_aux_device(pdata, &pdata->aux_aux, "aux");
1965 }
1966 
1967 static struct i2c_device_id ti_sn65dsi86_id[] = {
1968 	{ "ti,sn65dsi86", 0},
1969 	{},
1970 };
1971 MODULE_DEVICE_TABLE(i2c, ti_sn65dsi86_id);
1972 
1973 static const struct of_device_id ti_sn65dsi86_match_table[] = {
1974 	{.compatible = "ti,sn65dsi86"},
1975 	{},
1976 };
1977 MODULE_DEVICE_TABLE(of, ti_sn65dsi86_match_table);
1978 
1979 static struct i2c_driver ti_sn65dsi86_driver = {
1980 	.driver = {
1981 		.name = "ti_sn65dsi86",
1982 		.of_match_table = ti_sn65dsi86_match_table,
1983 		.pm = &ti_sn65dsi86_pm_ops,
1984 	},
1985 	.probe = ti_sn65dsi86_probe,
1986 	.id_table = ti_sn65dsi86_id,
1987 };
1988 
1989 static int __init ti_sn65dsi86_init(void)
1990 {
1991 	int ret;
1992 
1993 	ret = i2c_add_driver(&ti_sn65dsi86_driver);
1994 	if (ret)
1995 		return ret;
1996 
1997 	ret = ti_sn_gpio_register();
1998 	if (ret)
1999 		goto err_main_was_registered;
2000 
2001 	ret = ti_sn_pwm_register();
2002 	if (ret)
2003 		goto err_gpio_was_registered;
2004 
2005 	ret = auxiliary_driver_register(&ti_sn_aux_driver);
2006 	if (ret)
2007 		goto err_pwm_was_registered;
2008 
2009 	ret = auxiliary_driver_register(&ti_sn_bridge_driver);
2010 	if (ret)
2011 		goto err_aux_was_registered;
2012 
2013 	return 0;
2014 
2015 err_aux_was_registered:
2016 	auxiliary_driver_unregister(&ti_sn_aux_driver);
2017 err_pwm_was_registered:
2018 	ti_sn_pwm_unregister();
2019 err_gpio_was_registered:
2020 	ti_sn_gpio_unregister();
2021 err_main_was_registered:
2022 	i2c_del_driver(&ti_sn65dsi86_driver);
2023 
2024 	return ret;
2025 }
2026 module_init(ti_sn65dsi86_init);
2027 
2028 static void __exit ti_sn65dsi86_exit(void)
2029 {
2030 	auxiliary_driver_unregister(&ti_sn_bridge_driver);
2031 	auxiliary_driver_unregister(&ti_sn_aux_driver);
2032 	ti_sn_pwm_unregister();
2033 	ti_sn_gpio_unregister();
2034 	i2c_del_driver(&ti_sn65dsi86_driver);
2035 }
2036 module_exit(ti_sn65dsi86_exit);
2037 
2038 MODULE_AUTHOR("Sandeep Panda <spanda@codeaurora.org>");
2039 MODULE_DESCRIPTION("sn65dsi86 DSI to eDP bridge driver");
2040 MODULE_LICENSE("GPL v2");
2041