xref: /linux/drivers/gpu/drm/bridge/tc358767.c (revision 987b741c52c7c6c68d46fbaeb95b8d1087f10b7f)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * tc358767 eDP bridge driver
4  *
5  * Copyright (C) 2016 CogentEmbedded Inc
6  * Author: Andrey Gusakov <andrey.gusakov@cogentembedded.com>
7  *
8  * Copyright (C) 2016 Pengutronix, Philipp Zabel <p.zabel@pengutronix.de>
9  *
10  * Copyright (C) 2016 Zodiac Inflight Innovations
11  *
12  * Initially based on: drivers/gpu/drm/i2c/tda998x_drv.c
13  *
14  * Copyright (C) 2012 Texas Instruments
15  * Author: Rob Clark <robdclark@gmail.com>
16  */
17 
18 #include <linux/bitfield.h>
19 #include <linux/clk.h>
20 #include <linux/device.h>
21 #include <linux/gpio/consumer.h>
22 #include <linux/i2c.h>
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/regmap.h>
26 #include <linux/slab.h>
27 
28 #include <drm/drm_atomic_helper.h>
29 #include <drm/drm_bridge.h>
30 #include <drm/drm_dp_helper.h>
31 #include <drm/drm_edid.h>
32 #include <drm/drm_of.h>
33 #include <drm/drm_panel.h>
34 #include <drm/drm_print.h>
35 #include <drm/drm_probe_helper.h>
36 
37 /* Registers */
38 
39 /* Display Parallel Interface */
40 #define DPIPXLFMT		0x0440
41 #define VS_POL_ACTIVE_LOW		(1 << 10)
42 #define HS_POL_ACTIVE_LOW		(1 << 9)
43 #define DE_POL_ACTIVE_HIGH		(0 << 8)
44 #define SUB_CFG_TYPE_CONFIG1		(0 << 2) /* LSB aligned */
45 #define SUB_CFG_TYPE_CONFIG2		(1 << 2) /* Loosely Packed */
46 #define SUB_CFG_TYPE_CONFIG3		(2 << 2) /* LSB aligned 8-bit */
47 #define DPI_BPP_RGB888			(0 << 0)
48 #define DPI_BPP_RGB666			(1 << 0)
49 #define DPI_BPP_RGB565			(2 << 0)
50 
51 /* Video Path */
52 #define VPCTRL0			0x0450
53 #define VSDELAY			GENMASK(31, 20)
54 #define OPXLFMT_RGB666			(0 << 8)
55 #define OPXLFMT_RGB888			(1 << 8)
56 #define FRMSYNC_DISABLED		(0 << 4) /* Video Timing Gen Disabled */
57 #define FRMSYNC_ENABLED			(1 << 4) /* Video Timing Gen Enabled */
58 #define MSF_DISABLED			(0 << 0) /* Magic Square FRC disabled */
59 #define MSF_ENABLED			(1 << 0) /* Magic Square FRC enabled */
60 #define HTIM01			0x0454
61 #define HPW			GENMASK(8, 0)
62 #define HBPR			GENMASK(24, 16)
63 #define HTIM02			0x0458
64 #define HDISPR			GENMASK(10, 0)
65 #define HFPR			GENMASK(24, 16)
66 #define VTIM01			0x045c
67 #define VSPR			GENMASK(7, 0)
68 #define VBPR			GENMASK(23, 16)
69 #define VTIM02			0x0460
70 #define VFPR			GENMASK(23, 16)
71 #define VDISPR			GENMASK(10, 0)
72 #define VFUEN0			0x0464
73 #define VFUEN				BIT(0)   /* Video Frame Timing Upload */
74 
75 /* System */
76 #define TC_IDREG		0x0500
77 #define SYSSTAT			0x0508
78 #define SYSCTRL			0x0510
79 #define DP0_AUDSRC_NO_INPUT		(0 << 3)
80 #define DP0_AUDSRC_I2S_RX		(1 << 3)
81 #define DP0_VIDSRC_NO_INPUT		(0 << 0)
82 #define DP0_VIDSRC_DSI_RX		(1 << 0)
83 #define DP0_VIDSRC_DPI_RX		(2 << 0)
84 #define DP0_VIDSRC_COLOR_BAR		(3 << 0)
85 #define SYSRSTENB		0x050c
86 #define ENBI2C				(1 << 0)
87 #define ENBLCD0				(1 << 2)
88 #define ENBBM				(1 << 3)
89 #define ENBDSIRX			(1 << 4)
90 #define ENBREG				(1 << 5)
91 #define ENBHDCP				(1 << 8)
92 #define GPIOM			0x0540
93 #define GPIOC			0x0544
94 #define GPIOO			0x0548
95 #define GPIOI			0x054c
96 #define INTCTL_G		0x0560
97 #define INTSTS_G		0x0564
98 
99 #define INT_SYSERR		BIT(16)
100 #define INT_GPIO_H(x)		(1 << (x == 0 ? 2 : 10))
101 #define INT_GPIO_LC(x)		(1 << (x == 0 ? 3 : 11))
102 
103 #define INT_GP0_LCNT		0x0584
104 #define INT_GP1_LCNT		0x0588
105 
106 /* Control */
107 #define DP0CTL			0x0600
108 #define VID_MN_GEN			BIT(6)   /* Auto-generate M/N values */
109 #define EF_EN				BIT(5)   /* Enable Enhanced Framing */
110 #define VID_EN				BIT(1)   /* Video transmission enable */
111 #define DP_EN				BIT(0)   /* Enable DPTX function */
112 
113 /* Clocks */
114 #define DP0_VIDMNGEN0		0x0610
115 #define DP0_VIDMNGEN1		0x0614
116 #define DP0_VMNGENSTATUS	0x0618
117 
118 /* Main Channel */
119 #define DP0_SECSAMPLE		0x0640
120 #define DP0_VIDSYNCDELAY	0x0644
121 #define VID_SYNC_DLY		GENMASK(15, 0)
122 #define THRESH_DLY		GENMASK(31, 16)
123 
124 #define DP0_TOTALVAL		0x0648
125 #define H_TOTAL			GENMASK(15, 0)
126 #define V_TOTAL			GENMASK(31, 16)
127 #define DP0_STARTVAL		0x064c
128 #define H_START			GENMASK(15, 0)
129 #define V_START			GENMASK(31, 16)
130 #define DP0_ACTIVEVAL		0x0650
131 #define H_ACT			GENMASK(15, 0)
132 #define V_ACT			GENMASK(31, 16)
133 
134 #define DP0_SYNCVAL		0x0654
135 #define VS_WIDTH		GENMASK(30, 16)
136 #define HS_WIDTH		GENMASK(14, 0)
137 #define SYNCVAL_HS_POL_ACTIVE_LOW	(1 << 15)
138 #define SYNCVAL_VS_POL_ACTIVE_LOW	(1 << 31)
139 #define DP0_MISC		0x0658
140 #define TU_SIZE_RECOMMENDED		(63) /* LSCLK cycles per TU */
141 #define MAX_TU_SYMBOL		GENMASK(28, 23)
142 #define TU_SIZE			GENMASK(21, 16)
143 #define BPC_6				(0 << 5)
144 #define BPC_8				(1 << 5)
145 
146 /* AUX channel */
147 #define DP0_AUXCFG0		0x0660
148 #define DP0_AUXCFG0_BSIZE	GENMASK(11, 8)
149 #define DP0_AUXCFG0_ADDR_ONLY	BIT(4)
150 #define DP0_AUXCFG1		0x0664
151 #define AUX_RX_FILTER_EN		BIT(16)
152 
153 #define DP0_AUXADDR		0x0668
154 #define DP0_AUXWDATA(i)		(0x066c + (i) * 4)
155 #define DP0_AUXRDATA(i)		(0x067c + (i) * 4)
156 #define DP0_AUXSTATUS		0x068c
157 #define AUX_BYTES		GENMASK(15, 8)
158 #define AUX_STATUS		GENMASK(7, 4)
159 #define AUX_TIMEOUT		BIT(1)
160 #define AUX_BUSY		BIT(0)
161 #define DP0_AUXI2CADR		0x0698
162 
163 /* Link Training */
164 #define DP0_SRCCTRL		0x06a0
165 #define DP0_SRCCTRL_SCRMBLDIS		BIT(13)
166 #define DP0_SRCCTRL_EN810B		BIT(12)
167 #define DP0_SRCCTRL_NOTP		(0 << 8)
168 #define DP0_SRCCTRL_TP1			(1 << 8)
169 #define DP0_SRCCTRL_TP2			(2 << 8)
170 #define DP0_SRCCTRL_LANESKEW		BIT(7)
171 #define DP0_SRCCTRL_SSCG		BIT(3)
172 #define DP0_SRCCTRL_LANES_1		(0 << 2)
173 #define DP0_SRCCTRL_LANES_2		(1 << 2)
174 #define DP0_SRCCTRL_BW27		(1 << 1)
175 #define DP0_SRCCTRL_BW162		(0 << 1)
176 #define DP0_SRCCTRL_AUTOCORRECT		BIT(0)
177 #define DP0_LTSTAT		0x06d0
178 #define LT_LOOPDONE			BIT(13)
179 #define LT_STATUS_MASK			(0x1f << 8)
180 #define LT_CHANNEL1_EQ_BITS		(DP_CHANNEL_EQ_BITS << 4)
181 #define LT_INTERLANE_ALIGN_DONE		BIT(3)
182 #define LT_CHANNEL0_EQ_BITS		(DP_CHANNEL_EQ_BITS)
183 #define DP0_SNKLTCHGREQ		0x06d4
184 #define DP0_LTLOOPCTRL		0x06d8
185 #define DP0_SNKLTCTRL		0x06e4
186 
187 #define DP1_SRCCTRL		0x07a0
188 
189 /* PHY */
190 #define DP_PHY_CTRL		0x0800
191 #define DP_PHY_RST			BIT(28)  /* DP PHY Global Soft Reset */
192 #define BGREN				BIT(25)  /* AUX PHY BGR Enable */
193 #define PWR_SW_EN			BIT(24)  /* PHY Power Switch Enable */
194 #define PHY_M1_RST			BIT(12)  /* Reset PHY1 Main Channel */
195 #define PHY_RDY				BIT(16)  /* PHY Main Channels Ready */
196 #define PHY_M0_RST			BIT(8)   /* Reset PHY0 Main Channel */
197 #define PHY_2LANE			BIT(2)   /* PHY Enable 2 lanes */
198 #define PHY_A0_EN			BIT(1)   /* PHY Aux Channel0 Enable */
199 #define PHY_M0_EN			BIT(0)   /* PHY Main Channel0 Enable */
200 
201 /* PLL */
202 #define DP0_PLLCTRL		0x0900
203 #define DP1_PLLCTRL		0x0904	/* not defined in DS */
204 #define PXL_PLLCTRL		0x0908
205 #define PLLUPDATE			BIT(2)
206 #define PLLBYP				BIT(1)
207 #define PLLEN				BIT(0)
208 #define PXL_PLLPARAM		0x0914
209 #define IN_SEL_REFCLK			(0 << 14)
210 #define SYS_PLLPARAM		0x0918
211 #define REF_FREQ_38M4			(0 << 8) /* 38.4 MHz */
212 #define REF_FREQ_19M2			(1 << 8) /* 19.2 MHz */
213 #define REF_FREQ_26M			(2 << 8) /* 26 MHz */
214 #define REF_FREQ_13M			(3 << 8) /* 13 MHz */
215 #define SYSCLK_SEL_LSCLK		(0 << 4)
216 #define LSCLK_DIV_1			(0 << 0)
217 #define LSCLK_DIV_2			(1 << 0)
218 
219 /* Test & Debug */
220 #define TSTCTL			0x0a00
221 #define COLOR_R			GENMASK(31, 24)
222 #define COLOR_G			GENMASK(23, 16)
223 #define COLOR_B			GENMASK(15, 8)
224 #define ENI2CFILTER		BIT(4)
225 #define COLOR_BAR_MODE		GENMASK(1, 0)
226 #define COLOR_BAR_MODE_BARS	2
227 #define PLL_DBG			0x0a04
228 
229 static bool tc_test_pattern;
230 module_param_named(test, tc_test_pattern, bool, 0644);
231 
232 struct tc_edp_link {
233 	u8			dpcd[DP_RECEIVER_CAP_SIZE];
234 	unsigned int		rate;
235 	u8			num_lanes;
236 	u8			assr;
237 	bool			scrambler_dis;
238 	bool			spread;
239 };
240 
241 struct tc_data {
242 	struct device		*dev;
243 	struct regmap		*regmap;
244 	struct drm_dp_aux	aux;
245 
246 	struct drm_bridge	bridge;
247 	struct drm_bridge	*panel_bridge;
248 	struct drm_connector	connector;
249 
250 	/* link settings */
251 	struct tc_edp_link	link;
252 
253 	/* current mode */
254 	struct drm_display_mode	mode;
255 
256 	u32			rev;
257 	u8			assr;
258 
259 	struct gpio_desc	*sd_gpio;
260 	struct gpio_desc	*reset_gpio;
261 	struct clk		*refclk;
262 
263 	/* do we have IRQ */
264 	bool			have_irq;
265 
266 	/* HPD pin number (0 or 1) or -ENODEV */
267 	int			hpd_pin;
268 };
269 
270 static inline struct tc_data *aux_to_tc(struct drm_dp_aux *a)
271 {
272 	return container_of(a, struct tc_data, aux);
273 }
274 
275 static inline struct tc_data *bridge_to_tc(struct drm_bridge *b)
276 {
277 	return container_of(b, struct tc_data, bridge);
278 }
279 
280 static inline struct tc_data *connector_to_tc(struct drm_connector *c)
281 {
282 	return container_of(c, struct tc_data, connector);
283 }
284 
285 static inline int tc_poll_timeout(struct tc_data *tc, unsigned int addr,
286 				  unsigned int cond_mask,
287 				  unsigned int cond_value,
288 				  unsigned long sleep_us, u64 timeout_us)
289 {
290 	unsigned int val;
291 
292 	return regmap_read_poll_timeout(tc->regmap, addr, val,
293 					(val & cond_mask) == cond_value,
294 					sleep_us, timeout_us);
295 }
296 
297 static int tc_aux_wait_busy(struct tc_data *tc)
298 {
299 	return tc_poll_timeout(tc, DP0_AUXSTATUS, AUX_BUSY, 0, 100, 100000);
300 }
301 
302 static int tc_aux_write_data(struct tc_data *tc, const void *data,
303 			     size_t size)
304 {
305 	u32 auxwdata[DP_AUX_MAX_PAYLOAD_BYTES / sizeof(u32)] = { 0 };
306 	int ret, count = ALIGN(size, sizeof(u32));
307 
308 	memcpy(auxwdata, data, size);
309 
310 	ret = regmap_raw_write(tc->regmap, DP0_AUXWDATA(0), auxwdata, count);
311 	if (ret)
312 		return ret;
313 
314 	return size;
315 }
316 
317 static int tc_aux_read_data(struct tc_data *tc, void *data, size_t size)
318 {
319 	u32 auxrdata[DP_AUX_MAX_PAYLOAD_BYTES / sizeof(u32)];
320 	int ret, count = ALIGN(size, sizeof(u32));
321 
322 	ret = regmap_raw_read(tc->regmap, DP0_AUXRDATA(0), auxrdata, count);
323 	if (ret)
324 		return ret;
325 
326 	memcpy(data, auxrdata, size);
327 
328 	return size;
329 }
330 
331 static u32 tc_auxcfg0(struct drm_dp_aux_msg *msg, size_t size)
332 {
333 	u32 auxcfg0 = msg->request;
334 
335 	if (size)
336 		auxcfg0 |= FIELD_PREP(DP0_AUXCFG0_BSIZE, size - 1);
337 	else
338 		auxcfg0 |= DP0_AUXCFG0_ADDR_ONLY;
339 
340 	return auxcfg0;
341 }
342 
343 static ssize_t tc_aux_transfer(struct drm_dp_aux *aux,
344 			       struct drm_dp_aux_msg *msg)
345 {
346 	struct tc_data *tc = aux_to_tc(aux);
347 	size_t size = min_t(size_t, DP_AUX_MAX_PAYLOAD_BYTES - 1, msg->size);
348 	u8 request = msg->request & ~DP_AUX_I2C_MOT;
349 	u32 auxstatus;
350 	int ret;
351 
352 	ret = tc_aux_wait_busy(tc);
353 	if (ret)
354 		return ret;
355 
356 	switch (request) {
357 	case DP_AUX_NATIVE_READ:
358 	case DP_AUX_I2C_READ:
359 		break;
360 	case DP_AUX_NATIVE_WRITE:
361 	case DP_AUX_I2C_WRITE:
362 		if (size) {
363 			ret = tc_aux_write_data(tc, msg->buffer, size);
364 			if (ret < 0)
365 				return ret;
366 		}
367 		break;
368 	default:
369 		return -EINVAL;
370 	}
371 
372 	/* Store address */
373 	ret = regmap_write(tc->regmap, DP0_AUXADDR, msg->address);
374 	if (ret)
375 		return ret;
376 	/* Start transfer */
377 	ret = regmap_write(tc->regmap, DP0_AUXCFG0, tc_auxcfg0(msg, size));
378 	if (ret)
379 		return ret;
380 
381 	ret = tc_aux_wait_busy(tc);
382 	if (ret)
383 		return ret;
384 
385 	ret = regmap_read(tc->regmap, DP0_AUXSTATUS, &auxstatus);
386 	if (ret)
387 		return ret;
388 
389 	if (auxstatus & AUX_TIMEOUT)
390 		return -ETIMEDOUT;
391 	/*
392 	 * For some reason address-only DP_AUX_I2C_WRITE (MOT), still
393 	 * reports 1 byte transferred in its status. To deal we that
394 	 * we ignore aux_bytes field if we know that this was an
395 	 * address-only transfer
396 	 */
397 	if (size)
398 		size = FIELD_GET(AUX_BYTES, auxstatus);
399 	msg->reply = FIELD_GET(AUX_STATUS, auxstatus);
400 
401 	switch (request) {
402 	case DP_AUX_NATIVE_READ:
403 	case DP_AUX_I2C_READ:
404 		if (size)
405 			return tc_aux_read_data(tc, msg->buffer, size);
406 		break;
407 	}
408 
409 	return size;
410 }
411 
412 static const char * const training_pattern1_errors[] = {
413 	"No errors",
414 	"Aux write error",
415 	"Aux read error",
416 	"Max voltage reached error",
417 	"Loop counter expired error",
418 	"res", "res", "res"
419 };
420 
421 static const char * const training_pattern2_errors[] = {
422 	"No errors",
423 	"Aux write error",
424 	"Aux read error",
425 	"Clock recovery failed error",
426 	"Loop counter expired error",
427 	"res", "res", "res"
428 };
429 
430 static u32 tc_srcctrl(struct tc_data *tc)
431 {
432 	/*
433 	 * No training pattern, skew lane 1 data by two LSCLK cycles with
434 	 * respect to lane 0 data, AutoCorrect Mode = 0
435 	 */
436 	u32 reg = DP0_SRCCTRL_NOTP | DP0_SRCCTRL_LANESKEW | DP0_SRCCTRL_EN810B;
437 
438 	if (tc->link.scrambler_dis)
439 		reg |= DP0_SRCCTRL_SCRMBLDIS;	/* Scrambler Disabled */
440 	if (tc->link.spread)
441 		reg |= DP0_SRCCTRL_SSCG;	/* Spread Spectrum Enable */
442 	if (tc->link.num_lanes == 2)
443 		reg |= DP0_SRCCTRL_LANES_2;	/* Two Main Channel Lanes */
444 	if (tc->link.rate != 162000)
445 		reg |= DP0_SRCCTRL_BW27;	/* 2.7 Gbps link */
446 	return reg;
447 }
448 
449 static int tc_pllupdate(struct tc_data *tc, unsigned int pllctrl)
450 {
451 	int ret;
452 
453 	ret = regmap_write(tc->regmap, pllctrl, PLLUPDATE | PLLEN);
454 	if (ret)
455 		return ret;
456 
457 	/* Wait for PLL to lock: up to 2.09 ms, depending on refclk */
458 	usleep_range(3000, 6000);
459 
460 	return 0;
461 }
462 
463 static int tc_pxl_pll_en(struct tc_data *tc, u32 refclk, u32 pixelclock)
464 {
465 	int ret;
466 	int i_pre, best_pre = 1;
467 	int i_post, best_post = 1;
468 	int div, best_div = 1;
469 	int mul, best_mul = 1;
470 	int delta, best_delta;
471 	int ext_div[] = {1, 2, 3, 5, 7};
472 	int best_pixelclock = 0;
473 	int vco_hi = 0;
474 	u32 pxl_pllparam;
475 
476 	dev_dbg(tc->dev, "PLL: requested %d pixelclock, ref %d\n", pixelclock,
477 		refclk);
478 	best_delta = pixelclock;
479 	/* Loop over all possible ext_divs, skipping invalid configurations */
480 	for (i_pre = 0; i_pre < ARRAY_SIZE(ext_div); i_pre++) {
481 		/*
482 		 * refclk / ext_pre_div should be in the 1 to 200 MHz range.
483 		 * We don't allow any refclk > 200 MHz, only check lower bounds.
484 		 */
485 		if (refclk / ext_div[i_pre] < 1000000)
486 			continue;
487 		for (i_post = 0; i_post < ARRAY_SIZE(ext_div); i_post++) {
488 			for (div = 1; div <= 16; div++) {
489 				u32 clk;
490 				u64 tmp;
491 
492 				tmp = pixelclock * ext_div[i_pre] *
493 				      ext_div[i_post] * div;
494 				do_div(tmp, refclk);
495 				mul = tmp;
496 
497 				/* Check limits */
498 				if ((mul < 1) || (mul > 128))
499 					continue;
500 
501 				clk = (refclk / ext_div[i_pre] / div) * mul;
502 				/*
503 				 * refclk * mul / (ext_pre_div * pre_div)
504 				 * should be in the 150 to 650 MHz range
505 				 */
506 				if ((clk > 650000000) || (clk < 150000000))
507 					continue;
508 
509 				clk = clk / ext_div[i_post];
510 				delta = clk - pixelclock;
511 
512 				if (abs(delta) < abs(best_delta)) {
513 					best_pre = i_pre;
514 					best_post = i_post;
515 					best_div = div;
516 					best_mul = mul;
517 					best_delta = delta;
518 					best_pixelclock = clk;
519 				}
520 			}
521 		}
522 	}
523 	if (best_pixelclock == 0) {
524 		dev_err(tc->dev, "Failed to calc clock for %d pixelclock\n",
525 			pixelclock);
526 		return -EINVAL;
527 	}
528 
529 	dev_dbg(tc->dev, "PLL: got %d, delta %d\n", best_pixelclock,
530 		best_delta);
531 	dev_dbg(tc->dev, "PLL: %d / %d / %d * %d / %d\n", refclk,
532 		ext_div[best_pre], best_div, best_mul, ext_div[best_post]);
533 
534 	/* if VCO >= 300 MHz */
535 	if (refclk / ext_div[best_pre] / best_div * best_mul >= 300000000)
536 		vco_hi = 1;
537 	/* see DS */
538 	if (best_div == 16)
539 		best_div = 0;
540 	if (best_mul == 128)
541 		best_mul = 0;
542 
543 	/* Power up PLL and switch to bypass */
544 	ret = regmap_write(tc->regmap, PXL_PLLCTRL, PLLBYP | PLLEN);
545 	if (ret)
546 		return ret;
547 
548 	pxl_pllparam  = vco_hi << 24; /* For PLL VCO >= 300 MHz = 1 */
549 	pxl_pllparam |= ext_div[best_pre] << 20; /* External Pre-divider */
550 	pxl_pllparam |= ext_div[best_post] << 16; /* External Post-divider */
551 	pxl_pllparam |= IN_SEL_REFCLK; /* Use RefClk as PLL input */
552 	pxl_pllparam |= best_div << 8; /* Divider for PLL RefClk */
553 	pxl_pllparam |= best_mul; /* Multiplier for PLL */
554 
555 	ret = regmap_write(tc->regmap, PXL_PLLPARAM, pxl_pllparam);
556 	if (ret)
557 		return ret;
558 
559 	/* Force PLL parameter update and disable bypass */
560 	return tc_pllupdate(tc, PXL_PLLCTRL);
561 }
562 
563 static int tc_pxl_pll_dis(struct tc_data *tc)
564 {
565 	/* Enable PLL bypass, power down PLL */
566 	return regmap_write(tc->regmap, PXL_PLLCTRL, PLLBYP);
567 }
568 
569 static int tc_stream_clock_calc(struct tc_data *tc)
570 {
571 	/*
572 	 * If the Stream clock and Link Symbol clock are
573 	 * asynchronous with each other, the value of M changes over
574 	 * time. This way of generating link clock and stream
575 	 * clock is called Asynchronous Clock mode. The value M
576 	 * must change while the value N stays constant. The
577 	 * value of N in this Asynchronous Clock mode must be set
578 	 * to 2^15 or 32,768.
579 	 *
580 	 * LSCLK = 1/10 of high speed link clock
581 	 *
582 	 * f_STRMCLK = M/N * f_LSCLK
583 	 * M/N = f_STRMCLK / f_LSCLK
584 	 *
585 	 */
586 	return regmap_write(tc->regmap, DP0_VIDMNGEN1, 32768);
587 }
588 
589 static int tc_set_syspllparam(struct tc_data *tc)
590 {
591 	unsigned long rate;
592 	u32 pllparam = SYSCLK_SEL_LSCLK | LSCLK_DIV_2;
593 
594 	rate = clk_get_rate(tc->refclk);
595 	switch (rate) {
596 	case 38400000:
597 		pllparam |= REF_FREQ_38M4;
598 		break;
599 	case 26000000:
600 		pllparam |= REF_FREQ_26M;
601 		break;
602 	case 19200000:
603 		pllparam |= REF_FREQ_19M2;
604 		break;
605 	case 13000000:
606 		pllparam |= REF_FREQ_13M;
607 		break;
608 	default:
609 		dev_err(tc->dev, "Invalid refclk rate: %lu Hz\n", rate);
610 		return -EINVAL;
611 	}
612 
613 	return regmap_write(tc->regmap, SYS_PLLPARAM, pllparam);
614 }
615 
616 static int tc_aux_link_setup(struct tc_data *tc)
617 {
618 	int ret;
619 	u32 dp0_auxcfg1;
620 
621 	/* Setup DP-PHY / PLL */
622 	ret = tc_set_syspllparam(tc);
623 	if (ret)
624 		goto err;
625 
626 	ret = regmap_write(tc->regmap, DP_PHY_CTRL,
627 			   BGREN | PWR_SW_EN | PHY_A0_EN);
628 	if (ret)
629 		goto err;
630 	/*
631 	 * Initially PLLs are in bypass. Force PLL parameter update,
632 	 * disable PLL bypass, enable PLL
633 	 */
634 	ret = tc_pllupdate(tc, DP0_PLLCTRL);
635 	if (ret)
636 		goto err;
637 
638 	ret = tc_pllupdate(tc, DP1_PLLCTRL);
639 	if (ret)
640 		goto err;
641 
642 	ret = tc_poll_timeout(tc, DP_PHY_CTRL, PHY_RDY, PHY_RDY, 100, 100000);
643 	if (ret == -ETIMEDOUT) {
644 		dev_err(tc->dev, "Timeout waiting for PHY to become ready");
645 		return ret;
646 	} else if (ret) {
647 		goto err;
648 	}
649 
650 	/* Setup AUX link */
651 	dp0_auxcfg1  = AUX_RX_FILTER_EN;
652 	dp0_auxcfg1 |= 0x06 << 8; /* Aux Bit Period Calculator Threshold */
653 	dp0_auxcfg1 |= 0x3f << 0; /* Aux Response Timeout Timer */
654 
655 	ret = regmap_write(tc->regmap, DP0_AUXCFG1, dp0_auxcfg1);
656 	if (ret)
657 		goto err;
658 
659 	return 0;
660 err:
661 	dev_err(tc->dev, "tc_aux_link_setup failed: %d\n", ret);
662 	return ret;
663 }
664 
665 static int tc_get_display_props(struct tc_data *tc)
666 {
667 	u8 revision, num_lanes;
668 	unsigned int rate;
669 	int ret;
670 	u8 reg;
671 
672 	/* Read DP Rx Link Capability */
673 	ret = drm_dp_dpcd_read(&tc->aux, DP_DPCD_REV, tc->link.dpcd,
674 			       DP_RECEIVER_CAP_SIZE);
675 	if (ret < 0)
676 		goto err_dpcd_read;
677 
678 	revision = tc->link.dpcd[DP_DPCD_REV];
679 	rate = drm_dp_max_link_rate(tc->link.dpcd);
680 	num_lanes = drm_dp_max_lane_count(tc->link.dpcd);
681 
682 	if (rate != 162000 && rate != 270000) {
683 		dev_dbg(tc->dev, "Falling to 2.7 Gbps rate\n");
684 		rate = 270000;
685 	}
686 
687 	tc->link.rate = rate;
688 
689 	if (num_lanes > 2) {
690 		dev_dbg(tc->dev, "Falling to 2 lanes\n");
691 		num_lanes = 2;
692 	}
693 
694 	tc->link.num_lanes = num_lanes;
695 
696 	ret = drm_dp_dpcd_readb(&tc->aux, DP_MAX_DOWNSPREAD, &reg);
697 	if (ret < 0)
698 		goto err_dpcd_read;
699 	tc->link.spread = reg & DP_MAX_DOWNSPREAD_0_5;
700 
701 	ret = drm_dp_dpcd_readb(&tc->aux, DP_MAIN_LINK_CHANNEL_CODING, &reg);
702 	if (ret < 0)
703 		goto err_dpcd_read;
704 
705 	tc->link.scrambler_dis = false;
706 	/* read assr */
707 	ret = drm_dp_dpcd_readb(&tc->aux, DP_EDP_CONFIGURATION_SET, &reg);
708 	if (ret < 0)
709 		goto err_dpcd_read;
710 	tc->link.assr = reg & DP_ALTERNATE_SCRAMBLER_RESET_ENABLE;
711 
712 	dev_dbg(tc->dev, "DPCD rev: %d.%d, rate: %s, lanes: %d, framing: %s\n",
713 		revision >> 4, revision & 0x0f,
714 		(tc->link.rate == 162000) ? "1.62Gbps" : "2.7Gbps",
715 		tc->link.num_lanes,
716 		drm_dp_enhanced_frame_cap(tc->link.dpcd) ?
717 		"enhanced" : "default");
718 	dev_dbg(tc->dev, "Downspread: %s, scrambler: %s\n",
719 		tc->link.spread ? "0.5%" : "0.0%",
720 		tc->link.scrambler_dis ? "disabled" : "enabled");
721 	dev_dbg(tc->dev, "Display ASSR: %d, TC358767 ASSR: %d\n",
722 		tc->link.assr, tc->assr);
723 
724 	return 0;
725 
726 err_dpcd_read:
727 	dev_err(tc->dev, "failed to read DPCD: %d\n", ret);
728 	return ret;
729 }
730 
731 static int tc_set_video_mode(struct tc_data *tc,
732 			     const struct drm_display_mode *mode)
733 {
734 	int ret;
735 	int vid_sync_dly;
736 	int max_tu_symbol;
737 
738 	int left_margin = mode->htotal - mode->hsync_end;
739 	int right_margin = mode->hsync_start - mode->hdisplay;
740 	int hsync_len = mode->hsync_end - mode->hsync_start;
741 	int upper_margin = mode->vtotal - mode->vsync_end;
742 	int lower_margin = mode->vsync_start - mode->vdisplay;
743 	int vsync_len = mode->vsync_end - mode->vsync_start;
744 	u32 dp0_syncval;
745 	u32 bits_per_pixel = 24;
746 	u32 in_bw, out_bw;
747 
748 	/*
749 	 * Recommended maximum number of symbols transferred in a transfer unit:
750 	 * DIV_ROUND_UP((input active video bandwidth in bytes) * tu_size,
751 	 *              (output active video bandwidth in bytes))
752 	 * Must be less than tu_size.
753 	 */
754 
755 	in_bw = mode->clock * bits_per_pixel / 8;
756 	out_bw = tc->link.num_lanes * tc->link.rate;
757 	max_tu_symbol = DIV_ROUND_UP(in_bw * TU_SIZE_RECOMMENDED, out_bw);
758 
759 	dev_dbg(tc->dev, "set mode %dx%d\n",
760 		mode->hdisplay, mode->vdisplay);
761 	dev_dbg(tc->dev, "H margin %d,%d sync %d\n",
762 		left_margin, right_margin, hsync_len);
763 	dev_dbg(tc->dev, "V margin %d,%d sync %d\n",
764 		upper_margin, lower_margin, vsync_len);
765 	dev_dbg(tc->dev, "total: %dx%d\n", mode->htotal, mode->vtotal);
766 
767 
768 	/*
769 	 * LCD Ctl Frame Size
770 	 * datasheet is not clear of vsdelay in case of DPI
771 	 * assume we do not need any delay when DPI is a source of
772 	 * sync signals
773 	 */
774 	ret = regmap_write(tc->regmap, VPCTRL0,
775 			   FIELD_PREP(VSDELAY, 0) |
776 			   OPXLFMT_RGB888 | FRMSYNC_DISABLED | MSF_DISABLED);
777 	if (ret)
778 		return ret;
779 
780 	ret = regmap_write(tc->regmap, HTIM01,
781 			   FIELD_PREP(HBPR, ALIGN(left_margin, 2)) |
782 			   FIELD_PREP(HPW, ALIGN(hsync_len, 2)));
783 	if (ret)
784 		return ret;
785 
786 	ret = regmap_write(tc->regmap, HTIM02,
787 			   FIELD_PREP(HDISPR, ALIGN(mode->hdisplay, 2)) |
788 			   FIELD_PREP(HFPR, ALIGN(right_margin, 2)));
789 	if (ret)
790 		return ret;
791 
792 	ret = regmap_write(tc->regmap, VTIM01,
793 			   FIELD_PREP(VBPR, upper_margin) |
794 			   FIELD_PREP(VSPR, vsync_len));
795 	if (ret)
796 		return ret;
797 
798 	ret = regmap_write(tc->regmap, VTIM02,
799 			   FIELD_PREP(VFPR, lower_margin) |
800 			   FIELD_PREP(VDISPR, mode->vdisplay));
801 	if (ret)
802 		return ret;
803 
804 	ret = regmap_write(tc->regmap, VFUEN0, VFUEN); /* update settings */
805 	if (ret)
806 		return ret;
807 
808 	/* Test pattern settings */
809 	ret = regmap_write(tc->regmap, TSTCTL,
810 			   FIELD_PREP(COLOR_R, 120) |
811 			   FIELD_PREP(COLOR_G, 20) |
812 			   FIELD_PREP(COLOR_B, 99) |
813 			   ENI2CFILTER |
814 			   FIELD_PREP(COLOR_BAR_MODE, COLOR_BAR_MODE_BARS));
815 	if (ret)
816 		return ret;
817 
818 	/* DP Main Stream Attributes */
819 	vid_sync_dly = hsync_len + left_margin + mode->hdisplay;
820 	ret = regmap_write(tc->regmap, DP0_VIDSYNCDELAY,
821 		 FIELD_PREP(THRESH_DLY, max_tu_symbol) |
822 		 FIELD_PREP(VID_SYNC_DLY, vid_sync_dly));
823 
824 	ret = regmap_write(tc->regmap, DP0_TOTALVAL,
825 			   FIELD_PREP(H_TOTAL, mode->htotal) |
826 			   FIELD_PREP(V_TOTAL, mode->vtotal));
827 	if (ret)
828 		return ret;
829 
830 	ret = regmap_write(tc->regmap, DP0_STARTVAL,
831 			   FIELD_PREP(H_START, left_margin + hsync_len) |
832 			   FIELD_PREP(V_START, upper_margin + vsync_len));
833 	if (ret)
834 		return ret;
835 
836 	ret = regmap_write(tc->regmap, DP0_ACTIVEVAL,
837 			   FIELD_PREP(V_ACT, mode->vdisplay) |
838 			   FIELD_PREP(H_ACT, mode->hdisplay));
839 	if (ret)
840 		return ret;
841 
842 	dp0_syncval = FIELD_PREP(VS_WIDTH, vsync_len) |
843 		      FIELD_PREP(HS_WIDTH, hsync_len);
844 
845 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
846 		dp0_syncval |= SYNCVAL_VS_POL_ACTIVE_LOW;
847 
848 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
849 		dp0_syncval |= SYNCVAL_HS_POL_ACTIVE_LOW;
850 
851 	ret = regmap_write(tc->regmap, DP0_SYNCVAL, dp0_syncval);
852 	if (ret)
853 		return ret;
854 
855 	ret = regmap_write(tc->regmap, DPIPXLFMT,
856 			   VS_POL_ACTIVE_LOW | HS_POL_ACTIVE_LOW |
857 			   DE_POL_ACTIVE_HIGH | SUB_CFG_TYPE_CONFIG1 |
858 			   DPI_BPP_RGB888);
859 	if (ret)
860 		return ret;
861 
862 	ret = regmap_write(tc->regmap, DP0_MISC,
863 			   FIELD_PREP(MAX_TU_SYMBOL, max_tu_symbol) |
864 			   FIELD_PREP(TU_SIZE, TU_SIZE_RECOMMENDED) |
865 			   BPC_8);
866 	if (ret)
867 		return ret;
868 
869 	return 0;
870 }
871 
872 static int tc_wait_link_training(struct tc_data *tc)
873 {
874 	u32 value;
875 	int ret;
876 
877 	ret = tc_poll_timeout(tc, DP0_LTSTAT, LT_LOOPDONE,
878 			      LT_LOOPDONE, 500, 100000);
879 	if (ret) {
880 		dev_err(tc->dev, "Link training timeout waiting for LT_LOOPDONE!\n");
881 		return ret;
882 	}
883 
884 	ret = regmap_read(tc->regmap, DP0_LTSTAT, &value);
885 	if (ret)
886 		return ret;
887 
888 	return (value >> 8) & 0x7;
889 }
890 
891 static int tc_main_link_enable(struct tc_data *tc)
892 {
893 	struct drm_dp_aux *aux = &tc->aux;
894 	struct device *dev = tc->dev;
895 	u32 dp_phy_ctrl;
896 	u32 value;
897 	int ret;
898 	u8 tmp[DP_LINK_STATUS_SIZE];
899 
900 	dev_dbg(tc->dev, "link enable\n");
901 
902 	ret = regmap_read(tc->regmap, DP0CTL, &value);
903 	if (ret)
904 		return ret;
905 
906 	if (WARN_ON(value & DP_EN)) {
907 		ret = regmap_write(tc->regmap, DP0CTL, 0);
908 		if (ret)
909 			return ret;
910 	}
911 
912 	ret = regmap_write(tc->regmap, DP0_SRCCTRL, tc_srcctrl(tc));
913 	if (ret)
914 		return ret;
915 	/* SSCG and BW27 on DP1 must be set to the same as on DP0 */
916 	ret = regmap_write(tc->regmap, DP1_SRCCTRL,
917 		 (tc->link.spread ? DP0_SRCCTRL_SSCG : 0) |
918 		 ((tc->link.rate != 162000) ? DP0_SRCCTRL_BW27 : 0));
919 	if (ret)
920 		return ret;
921 
922 	ret = tc_set_syspllparam(tc);
923 	if (ret)
924 		return ret;
925 
926 	/* Setup Main Link */
927 	dp_phy_ctrl = BGREN | PWR_SW_EN | PHY_A0_EN | PHY_M0_EN;
928 	if (tc->link.num_lanes == 2)
929 		dp_phy_ctrl |= PHY_2LANE;
930 
931 	ret = regmap_write(tc->regmap, DP_PHY_CTRL, dp_phy_ctrl);
932 	if (ret)
933 		return ret;
934 
935 	/* PLL setup */
936 	ret = tc_pllupdate(tc, DP0_PLLCTRL);
937 	if (ret)
938 		return ret;
939 
940 	ret = tc_pllupdate(tc, DP1_PLLCTRL);
941 	if (ret)
942 		return ret;
943 
944 	/* Reset/Enable Main Links */
945 	dp_phy_ctrl |= DP_PHY_RST | PHY_M1_RST | PHY_M0_RST;
946 	ret = regmap_write(tc->regmap, DP_PHY_CTRL, dp_phy_ctrl);
947 	usleep_range(100, 200);
948 	dp_phy_ctrl &= ~(DP_PHY_RST | PHY_M1_RST | PHY_M0_RST);
949 	ret = regmap_write(tc->regmap, DP_PHY_CTRL, dp_phy_ctrl);
950 
951 	ret = tc_poll_timeout(tc, DP_PHY_CTRL, PHY_RDY, PHY_RDY, 500, 100000);
952 	if (ret) {
953 		dev_err(dev, "timeout waiting for phy become ready");
954 		return ret;
955 	}
956 
957 	/* Set misc: 8 bits per color */
958 	ret = regmap_update_bits(tc->regmap, DP0_MISC, BPC_8, BPC_8);
959 	if (ret)
960 		return ret;
961 
962 	/*
963 	 * ASSR mode
964 	 * on TC358767 side ASSR configured through strap pin
965 	 * seems there is no way to change this setting from SW
966 	 *
967 	 * check is tc configured for same mode
968 	 */
969 	if (tc->assr != tc->link.assr) {
970 		dev_dbg(dev, "Trying to set display to ASSR: %d\n",
971 			tc->assr);
972 		/* try to set ASSR on display side */
973 		tmp[0] = tc->assr;
974 		ret = drm_dp_dpcd_writeb(aux, DP_EDP_CONFIGURATION_SET, tmp[0]);
975 		if (ret < 0)
976 			goto err_dpcd_read;
977 		/* read back */
978 		ret = drm_dp_dpcd_readb(aux, DP_EDP_CONFIGURATION_SET, tmp);
979 		if (ret < 0)
980 			goto err_dpcd_read;
981 
982 		if (tmp[0] != tc->assr) {
983 			dev_dbg(dev, "Failed to switch display ASSR to %d, falling back to unscrambled mode\n",
984 				tc->assr);
985 			/* trying with disabled scrambler */
986 			tc->link.scrambler_dis = true;
987 		}
988 	}
989 
990 	/* Setup Link & DPRx Config for Training */
991 	tmp[0] = drm_dp_link_rate_to_bw_code(tc->link.rate);
992 	tmp[1] = tc->link.num_lanes;
993 
994 	if (drm_dp_enhanced_frame_cap(tc->link.dpcd))
995 		tmp[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
996 
997 	ret = drm_dp_dpcd_write(aux, DP_LINK_BW_SET, tmp, 2);
998 	if (ret < 0)
999 		goto err_dpcd_write;
1000 
1001 	/* DOWNSPREAD_CTRL */
1002 	tmp[0] = tc->link.spread ? DP_SPREAD_AMP_0_5 : 0x00;
1003 	/* MAIN_LINK_CHANNEL_CODING_SET */
1004 	tmp[1] =  DP_SET_ANSI_8B10B;
1005 	ret = drm_dp_dpcd_write(aux, DP_DOWNSPREAD_CTRL, tmp, 2);
1006 	if (ret < 0)
1007 		goto err_dpcd_write;
1008 
1009 	/* Reset voltage-swing & pre-emphasis */
1010 	tmp[0] = tmp[1] = DP_TRAIN_VOLTAGE_SWING_LEVEL_0 |
1011 			  DP_TRAIN_PRE_EMPH_LEVEL_0;
1012 	ret = drm_dp_dpcd_write(aux, DP_TRAINING_LANE0_SET, tmp, 2);
1013 	if (ret < 0)
1014 		goto err_dpcd_write;
1015 
1016 	/* Clock-Recovery */
1017 
1018 	/* Set DPCD 0x102 for Training Pattern 1 */
1019 	ret = regmap_write(tc->regmap, DP0_SNKLTCTRL,
1020 			   DP_LINK_SCRAMBLING_DISABLE |
1021 			   DP_TRAINING_PATTERN_1);
1022 	if (ret)
1023 		return ret;
1024 
1025 	ret = regmap_write(tc->regmap, DP0_LTLOOPCTRL,
1026 			   (15 << 28) |	/* Defer Iteration Count */
1027 			   (15 << 24) |	/* Loop Iteration Count */
1028 			   (0xd << 0));	/* Loop Timer Delay */
1029 	if (ret)
1030 		return ret;
1031 
1032 	ret = regmap_write(tc->regmap, DP0_SRCCTRL,
1033 			   tc_srcctrl(tc) | DP0_SRCCTRL_SCRMBLDIS |
1034 			   DP0_SRCCTRL_AUTOCORRECT |
1035 			   DP0_SRCCTRL_TP1);
1036 	if (ret)
1037 		return ret;
1038 
1039 	/* Enable DP0 to start Link Training */
1040 	ret = regmap_write(tc->regmap, DP0CTL,
1041 			   (drm_dp_enhanced_frame_cap(tc->link.dpcd) ?
1042 				EF_EN : 0) | DP_EN);
1043 	if (ret)
1044 		return ret;
1045 
1046 	/* wait */
1047 
1048 	ret = tc_wait_link_training(tc);
1049 	if (ret < 0)
1050 		return ret;
1051 
1052 	if (ret) {
1053 		dev_err(tc->dev, "Link training phase 1 failed: %s\n",
1054 			training_pattern1_errors[ret]);
1055 		return -ENODEV;
1056 	}
1057 
1058 	/* Channel Equalization */
1059 
1060 	/* Set DPCD 0x102 for Training Pattern 2 */
1061 	ret = regmap_write(tc->regmap, DP0_SNKLTCTRL,
1062 			   DP_LINK_SCRAMBLING_DISABLE |
1063 			   DP_TRAINING_PATTERN_2);
1064 	if (ret)
1065 		return ret;
1066 
1067 	ret = regmap_write(tc->regmap, DP0_SRCCTRL,
1068 			   tc_srcctrl(tc) | DP0_SRCCTRL_SCRMBLDIS |
1069 			   DP0_SRCCTRL_AUTOCORRECT |
1070 			   DP0_SRCCTRL_TP2);
1071 	if (ret)
1072 		return ret;
1073 
1074 	/* wait */
1075 	ret = tc_wait_link_training(tc);
1076 	if (ret < 0)
1077 		return ret;
1078 
1079 	if (ret) {
1080 		dev_err(tc->dev, "Link training phase 2 failed: %s\n",
1081 			training_pattern2_errors[ret]);
1082 		return -ENODEV;
1083 	}
1084 
1085 	/*
1086 	 * Toshiba's documentation suggests to first clear DPCD 0x102, then
1087 	 * clear the training pattern bit in DP0_SRCCTRL. Testing shows
1088 	 * that the link sometimes drops if those steps are done in that order,
1089 	 * but if the steps are done in reverse order, the link stays up.
1090 	 *
1091 	 * So we do the steps differently than documented here.
1092 	 */
1093 
1094 	/* Clear Training Pattern, set AutoCorrect Mode = 1 */
1095 	ret = regmap_write(tc->regmap, DP0_SRCCTRL, tc_srcctrl(tc) |
1096 			   DP0_SRCCTRL_AUTOCORRECT);
1097 	if (ret)
1098 		return ret;
1099 
1100 	/* Clear DPCD 0x102 */
1101 	/* Note: Can Not use DP0_SNKLTCTRL (0x06E4) short cut */
1102 	tmp[0] = tc->link.scrambler_dis ? DP_LINK_SCRAMBLING_DISABLE : 0x00;
1103 	ret = drm_dp_dpcd_writeb(aux, DP_TRAINING_PATTERN_SET, tmp[0]);
1104 	if (ret < 0)
1105 		goto err_dpcd_write;
1106 
1107 	/* Check link status */
1108 	ret = drm_dp_dpcd_read_link_status(aux, tmp);
1109 	if (ret < 0)
1110 		goto err_dpcd_read;
1111 
1112 	ret = 0;
1113 
1114 	value = tmp[0] & DP_CHANNEL_EQ_BITS;
1115 
1116 	if (value != DP_CHANNEL_EQ_BITS) {
1117 		dev_err(tc->dev, "Lane 0 failed: %x\n", value);
1118 		ret = -ENODEV;
1119 	}
1120 
1121 	if (tc->link.num_lanes == 2) {
1122 		value = (tmp[0] >> 4) & DP_CHANNEL_EQ_BITS;
1123 
1124 		if (value != DP_CHANNEL_EQ_BITS) {
1125 			dev_err(tc->dev, "Lane 1 failed: %x\n", value);
1126 			ret = -ENODEV;
1127 		}
1128 
1129 		if (!(tmp[2] & DP_INTERLANE_ALIGN_DONE)) {
1130 			dev_err(tc->dev, "Interlane align failed\n");
1131 			ret = -ENODEV;
1132 		}
1133 	}
1134 
1135 	if (ret) {
1136 		dev_err(dev, "0x0202 LANE0_1_STATUS:            0x%02x\n", tmp[0]);
1137 		dev_err(dev, "0x0203 LANE2_3_STATUS             0x%02x\n", tmp[1]);
1138 		dev_err(dev, "0x0204 LANE_ALIGN_STATUS_UPDATED: 0x%02x\n", tmp[2]);
1139 		dev_err(dev, "0x0205 SINK_STATUS:               0x%02x\n", tmp[3]);
1140 		dev_err(dev, "0x0206 ADJUST_REQUEST_LANE0_1:    0x%02x\n", tmp[4]);
1141 		dev_err(dev, "0x0207 ADJUST_REQUEST_LANE2_3:    0x%02x\n", tmp[5]);
1142 		return ret;
1143 	}
1144 
1145 	return 0;
1146 err_dpcd_read:
1147 	dev_err(tc->dev, "Failed to read DPCD: %d\n", ret);
1148 	return ret;
1149 err_dpcd_write:
1150 	dev_err(tc->dev, "Failed to write DPCD: %d\n", ret);
1151 	return ret;
1152 }
1153 
1154 static int tc_main_link_disable(struct tc_data *tc)
1155 {
1156 	int ret;
1157 
1158 	dev_dbg(tc->dev, "link disable\n");
1159 
1160 	ret = regmap_write(tc->regmap, DP0_SRCCTRL, 0);
1161 	if (ret)
1162 		return ret;
1163 
1164 	return regmap_write(tc->regmap, DP0CTL, 0);
1165 }
1166 
1167 static int tc_stream_enable(struct tc_data *tc)
1168 {
1169 	int ret;
1170 	u32 value;
1171 
1172 	dev_dbg(tc->dev, "enable video stream\n");
1173 
1174 	/* PXL PLL setup */
1175 	if (tc_test_pattern) {
1176 		ret = tc_pxl_pll_en(tc, clk_get_rate(tc->refclk),
1177 				    1000 * tc->mode.clock);
1178 		if (ret)
1179 			return ret;
1180 	}
1181 
1182 	ret = tc_set_video_mode(tc, &tc->mode);
1183 	if (ret)
1184 		return ret;
1185 
1186 	/* Set M/N */
1187 	ret = tc_stream_clock_calc(tc);
1188 	if (ret)
1189 		return ret;
1190 
1191 	value = VID_MN_GEN | DP_EN;
1192 	if (drm_dp_enhanced_frame_cap(tc->link.dpcd))
1193 		value |= EF_EN;
1194 	ret = regmap_write(tc->regmap, DP0CTL, value);
1195 	if (ret)
1196 		return ret;
1197 	/*
1198 	 * VID_EN assertion should be delayed by at least N * LSCLK
1199 	 * cycles from the time VID_MN_GEN is enabled in order to
1200 	 * generate stable values for VID_M. LSCLK is 270 MHz or
1201 	 * 162 MHz, VID_N is set to 32768 in  tc_stream_clock_calc(),
1202 	 * so a delay of at least 203 us should suffice.
1203 	 */
1204 	usleep_range(500, 1000);
1205 	value |= VID_EN;
1206 	ret = regmap_write(tc->regmap, DP0CTL, value);
1207 	if (ret)
1208 		return ret;
1209 	/* Set input interface */
1210 	value = DP0_AUDSRC_NO_INPUT;
1211 	if (tc_test_pattern)
1212 		value |= DP0_VIDSRC_COLOR_BAR;
1213 	else
1214 		value |= DP0_VIDSRC_DPI_RX;
1215 	ret = regmap_write(tc->regmap, SYSCTRL, value);
1216 	if (ret)
1217 		return ret;
1218 
1219 	return 0;
1220 }
1221 
1222 static int tc_stream_disable(struct tc_data *tc)
1223 {
1224 	int ret;
1225 
1226 	dev_dbg(tc->dev, "disable video stream\n");
1227 
1228 	ret = regmap_update_bits(tc->regmap, DP0CTL, VID_EN, 0);
1229 	if (ret)
1230 		return ret;
1231 
1232 	tc_pxl_pll_dis(tc);
1233 
1234 	return 0;
1235 }
1236 
1237 static void tc_bridge_enable(struct drm_bridge *bridge)
1238 {
1239 	struct tc_data *tc = bridge_to_tc(bridge);
1240 	int ret;
1241 
1242 	ret = tc_get_display_props(tc);
1243 	if (ret < 0) {
1244 		dev_err(tc->dev, "failed to read display props: %d\n", ret);
1245 		return;
1246 	}
1247 
1248 	ret = tc_main_link_enable(tc);
1249 	if (ret < 0) {
1250 		dev_err(tc->dev, "main link enable error: %d\n", ret);
1251 		return;
1252 	}
1253 
1254 	ret = tc_stream_enable(tc);
1255 	if (ret < 0) {
1256 		dev_err(tc->dev, "main link stream start error: %d\n", ret);
1257 		tc_main_link_disable(tc);
1258 		return;
1259 	}
1260 }
1261 
1262 static void tc_bridge_disable(struct drm_bridge *bridge)
1263 {
1264 	struct tc_data *tc = bridge_to_tc(bridge);
1265 	int ret;
1266 
1267 	ret = tc_stream_disable(tc);
1268 	if (ret < 0)
1269 		dev_err(tc->dev, "main link stream stop error: %d\n", ret);
1270 
1271 	ret = tc_main_link_disable(tc);
1272 	if (ret < 0)
1273 		dev_err(tc->dev, "main link disable error: %d\n", ret);
1274 }
1275 
1276 static bool tc_bridge_mode_fixup(struct drm_bridge *bridge,
1277 				 const struct drm_display_mode *mode,
1278 				 struct drm_display_mode *adj)
1279 {
1280 	/* Fixup sync polarities, both hsync and vsync are active low */
1281 	adj->flags = mode->flags;
1282 	adj->flags |= (DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC);
1283 	adj->flags &= ~(DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC);
1284 
1285 	return true;
1286 }
1287 
1288 static enum drm_mode_status tc_mode_valid(struct drm_bridge *bridge,
1289 					  const struct drm_display_info *info,
1290 					  const struct drm_display_mode *mode)
1291 {
1292 	struct tc_data *tc = bridge_to_tc(bridge);
1293 	u32 req, avail;
1294 	u32 bits_per_pixel = 24;
1295 
1296 	/* DPI interface clock limitation: upto 154 MHz */
1297 	if (mode->clock > 154000)
1298 		return MODE_CLOCK_HIGH;
1299 
1300 	req = mode->clock * bits_per_pixel / 8;
1301 	avail = tc->link.num_lanes * tc->link.rate;
1302 
1303 	if (req > avail)
1304 		return MODE_BAD;
1305 
1306 	return MODE_OK;
1307 }
1308 
1309 static void tc_bridge_mode_set(struct drm_bridge *bridge,
1310 			       const struct drm_display_mode *mode,
1311 			       const struct drm_display_mode *adj)
1312 {
1313 	struct tc_data *tc = bridge_to_tc(bridge);
1314 
1315 	tc->mode = *mode;
1316 }
1317 
1318 static struct edid *tc_get_edid(struct drm_bridge *bridge,
1319 				struct drm_connector *connector)
1320 {
1321 	struct tc_data *tc = bridge_to_tc(bridge);
1322 
1323 	return drm_get_edid(connector, &tc->aux.ddc);
1324 }
1325 
1326 static int tc_connector_get_modes(struct drm_connector *connector)
1327 {
1328 	struct tc_data *tc = connector_to_tc(connector);
1329 	int num_modes;
1330 	struct edid *edid;
1331 	int ret;
1332 
1333 	ret = tc_get_display_props(tc);
1334 	if (ret < 0) {
1335 		dev_err(tc->dev, "failed to read display props: %d\n", ret);
1336 		return 0;
1337 	}
1338 
1339 	if (tc->panel_bridge) {
1340 		num_modes = drm_bridge_get_modes(tc->panel_bridge, connector);
1341 		if (num_modes > 0)
1342 			return num_modes;
1343 	}
1344 
1345 	edid = tc_get_edid(&tc->bridge, connector);
1346 	num_modes = drm_add_edid_modes(connector, edid);
1347 	kfree(edid);
1348 
1349 	return num_modes;
1350 }
1351 
1352 static const struct drm_connector_helper_funcs tc_connector_helper_funcs = {
1353 	.get_modes = tc_connector_get_modes,
1354 };
1355 
1356 static enum drm_connector_status tc_bridge_detect(struct drm_bridge *bridge)
1357 {
1358 	struct tc_data *tc = bridge_to_tc(bridge);
1359 	bool conn;
1360 	u32 val;
1361 	int ret;
1362 
1363 	ret = regmap_read(tc->regmap, GPIOI, &val);
1364 	if (ret)
1365 		return connector_status_unknown;
1366 
1367 	conn = val & BIT(tc->hpd_pin);
1368 
1369 	if (conn)
1370 		return connector_status_connected;
1371 	else
1372 		return connector_status_disconnected;
1373 }
1374 
1375 static enum drm_connector_status
1376 tc_connector_detect(struct drm_connector *connector, bool force)
1377 {
1378 	struct tc_data *tc = connector_to_tc(connector);
1379 
1380 	if (tc->hpd_pin >= 0)
1381 		return tc_bridge_detect(&tc->bridge);
1382 
1383 	if (tc->panel_bridge)
1384 		return connector_status_connected;
1385 	else
1386 		return connector_status_unknown;
1387 }
1388 
1389 static const struct drm_connector_funcs tc_connector_funcs = {
1390 	.detect = tc_connector_detect,
1391 	.fill_modes = drm_helper_probe_single_connector_modes,
1392 	.destroy = drm_connector_cleanup,
1393 	.reset = drm_atomic_helper_connector_reset,
1394 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
1395 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
1396 };
1397 
1398 static int tc_bridge_attach(struct drm_bridge *bridge,
1399 			    enum drm_bridge_attach_flags flags)
1400 {
1401 	u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
1402 	struct tc_data *tc = bridge_to_tc(bridge);
1403 	struct drm_device *drm = bridge->dev;
1404 	int ret;
1405 
1406 	if (tc->panel_bridge) {
1407 		/* If a connector is required then this driver shall create it */
1408 		ret = drm_bridge_attach(tc->bridge.encoder, tc->panel_bridge,
1409 					&tc->bridge, flags | DRM_BRIDGE_ATTACH_NO_CONNECTOR);
1410 		if (ret)
1411 			return ret;
1412 	}
1413 
1414 	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
1415 		return 0;
1416 
1417 	ret = drm_dp_aux_register(&tc->aux);
1418 	if (ret < 0)
1419 		return ret;
1420 
1421 	/* Create DP/eDP connector */
1422 	drm_connector_helper_add(&tc->connector, &tc_connector_helper_funcs);
1423 	ret = drm_connector_init(drm, &tc->connector, &tc_connector_funcs, tc->bridge.type);
1424 	if (ret)
1425 		goto aux_unregister;
1426 
1427 	/* Don't poll if don't have HPD connected */
1428 	if (tc->hpd_pin >= 0) {
1429 		if (tc->have_irq)
1430 			tc->connector.polled = DRM_CONNECTOR_POLL_HPD;
1431 		else
1432 			tc->connector.polled = DRM_CONNECTOR_POLL_CONNECT |
1433 					       DRM_CONNECTOR_POLL_DISCONNECT;
1434 	}
1435 
1436 	drm_display_info_set_bus_formats(&tc->connector.display_info,
1437 					 &bus_format, 1);
1438 	tc->connector.display_info.bus_flags =
1439 		DRM_BUS_FLAG_DE_HIGH |
1440 		DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE |
1441 		DRM_BUS_FLAG_SYNC_DRIVE_NEGEDGE;
1442 	drm_connector_attach_encoder(&tc->connector, tc->bridge.encoder);
1443 
1444 	return 0;
1445 aux_unregister:
1446 	drm_dp_aux_unregister(&tc->aux);
1447 	return ret;
1448 }
1449 
1450 static void tc_bridge_detach(struct drm_bridge *bridge)
1451 {
1452 	drm_dp_aux_unregister(&bridge_to_tc(bridge)->aux);
1453 }
1454 
1455 static const struct drm_bridge_funcs tc_bridge_funcs = {
1456 	.attach = tc_bridge_attach,
1457 	.detach = tc_bridge_detach,
1458 	.mode_valid = tc_mode_valid,
1459 	.mode_set = tc_bridge_mode_set,
1460 	.enable = tc_bridge_enable,
1461 	.disable = tc_bridge_disable,
1462 	.mode_fixup = tc_bridge_mode_fixup,
1463 	.detect = tc_bridge_detect,
1464 	.get_edid = tc_get_edid,
1465 };
1466 
1467 static bool tc_readable_reg(struct device *dev, unsigned int reg)
1468 {
1469 	return reg != SYSCTRL;
1470 }
1471 
1472 static const struct regmap_range tc_volatile_ranges[] = {
1473 	regmap_reg_range(DP0_AUXWDATA(0), DP0_AUXSTATUS),
1474 	regmap_reg_range(DP0_LTSTAT, DP0_SNKLTCHGREQ),
1475 	regmap_reg_range(DP_PHY_CTRL, DP_PHY_CTRL),
1476 	regmap_reg_range(DP0_PLLCTRL, PXL_PLLCTRL),
1477 	regmap_reg_range(VFUEN0, VFUEN0),
1478 	regmap_reg_range(INTSTS_G, INTSTS_G),
1479 	regmap_reg_range(GPIOI, GPIOI),
1480 };
1481 
1482 static const struct regmap_access_table tc_volatile_table = {
1483 	.yes_ranges = tc_volatile_ranges,
1484 	.n_yes_ranges = ARRAY_SIZE(tc_volatile_ranges),
1485 };
1486 
1487 static bool tc_writeable_reg(struct device *dev, unsigned int reg)
1488 {
1489 	return (reg != TC_IDREG) &&
1490 	       (reg != DP0_LTSTAT) &&
1491 	       (reg != DP0_SNKLTCHGREQ);
1492 }
1493 
1494 static const struct regmap_config tc_regmap_config = {
1495 	.name = "tc358767",
1496 	.reg_bits = 16,
1497 	.val_bits = 32,
1498 	.reg_stride = 4,
1499 	.max_register = PLL_DBG,
1500 	.cache_type = REGCACHE_RBTREE,
1501 	.readable_reg = tc_readable_reg,
1502 	.volatile_table = &tc_volatile_table,
1503 	.writeable_reg = tc_writeable_reg,
1504 	.reg_format_endian = REGMAP_ENDIAN_BIG,
1505 	.val_format_endian = REGMAP_ENDIAN_LITTLE,
1506 };
1507 
1508 static irqreturn_t tc_irq_handler(int irq, void *arg)
1509 {
1510 	struct tc_data *tc = arg;
1511 	u32 val;
1512 	int r;
1513 
1514 	r = regmap_read(tc->regmap, INTSTS_G, &val);
1515 	if (r)
1516 		return IRQ_NONE;
1517 
1518 	if (!val)
1519 		return IRQ_NONE;
1520 
1521 	if (val & INT_SYSERR) {
1522 		u32 stat = 0;
1523 
1524 		regmap_read(tc->regmap, SYSSTAT, &stat);
1525 
1526 		dev_err(tc->dev, "syserr %x\n", stat);
1527 	}
1528 
1529 	if (tc->hpd_pin >= 0 && tc->bridge.dev) {
1530 		/*
1531 		 * H is triggered when the GPIO goes high.
1532 		 *
1533 		 * LC is triggered when the GPIO goes low and stays low for
1534 		 * the duration of LCNT
1535 		 */
1536 		bool h = val & INT_GPIO_H(tc->hpd_pin);
1537 		bool lc = val & INT_GPIO_LC(tc->hpd_pin);
1538 
1539 		dev_dbg(tc->dev, "GPIO%d: %s %s\n", tc->hpd_pin,
1540 			h ? "H" : "", lc ? "LC" : "");
1541 
1542 		if (h || lc)
1543 			drm_kms_helper_hotplug_event(tc->bridge.dev);
1544 	}
1545 
1546 	regmap_write(tc->regmap, INTSTS_G, val);
1547 
1548 	return IRQ_HANDLED;
1549 }
1550 
1551 static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id)
1552 {
1553 	struct device *dev = &client->dev;
1554 	struct drm_panel *panel;
1555 	struct tc_data *tc;
1556 	int ret;
1557 
1558 	tc = devm_kzalloc(dev, sizeof(*tc), GFP_KERNEL);
1559 	if (!tc)
1560 		return -ENOMEM;
1561 
1562 	tc->dev = dev;
1563 
1564 	/* port@2 is the output port */
1565 	ret = drm_of_find_panel_or_bridge(dev->of_node, 2, 0, &panel, NULL);
1566 	if (ret && ret != -ENODEV)
1567 		return ret;
1568 
1569 	if (panel) {
1570 		struct drm_bridge *panel_bridge;
1571 
1572 		panel_bridge = devm_drm_panel_bridge_add(dev, panel);
1573 		if (IS_ERR(panel_bridge))
1574 			return PTR_ERR(panel_bridge);
1575 
1576 		tc->panel_bridge = panel_bridge;
1577 		tc->bridge.type = DRM_MODE_CONNECTOR_eDP;
1578 	} else {
1579 		tc->bridge.type = DRM_MODE_CONNECTOR_DisplayPort;
1580 	}
1581 
1582 	/* Shut down GPIO is optional */
1583 	tc->sd_gpio = devm_gpiod_get_optional(dev, "shutdown", GPIOD_OUT_HIGH);
1584 	if (IS_ERR(tc->sd_gpio))
1585 		return PTR_ERR(tc->sd_gpio);
1586 
1587 	if (tc->sd_gpio) {
1588 		gpiod_set_value_cansleep(tc->sd_gpio, 0);
1589 		usleep_range(5000, 10000);
1590 	}
1591 
1592 	/* Reset GPIO is optional */
1593 	tc->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
1594 	if (IS_ERR(tc->reset_gpio))
1595 		return PTR_ERR(tc->reset_gpio);
1596 
1597 	if (tc->reset_gpio) {
1598 		gpiod_set_value_cansleep(tc->reset_gpio, 1);
1599 		usleep_range(5000, 10000);
1600 	}
1601 
1602 	tc->refclk = devm_clk_get(dev, "ref");
1603 	if (IS_ERR(tc->refclk)) {
1604 		ret = PTR_ERR(tc->refclk);
1605 		dev_err(dev, "Failed to get refclk: %d\n", ret);
1606 		return ret;
1607 	}
1608 
1609 	tc->regmap = devm_regmap_init_i2c(client, &tc_regmap_config);
1610 	if (IS_ERR(tc->regmap)) {
1611 		ret = PTR_ERR(tc->regmap);
1612 		dev_err(dev, "Failed to initialize regmap: %d\n", ret);
1613 		return ret;
1614 	}
1615 
1616 	ret = of_property_read_u32(dev->of_node, "toshiba,hpd-pin",
1617 				   &tc->hpd_pin);
1618 	if (ret) {
1619 		tc->hpd_pin = -ENODEV;
1620 	} else {
1621 		if (tc->hpd_pin < 0 || tc->hpd_pin > 1) {
1622 			dev_err(dev, "failed to parse HPD number\n");
1623 			return ret;
1624 		}
1625 	}
1626 
1627 	if (client->irq > 0) {
1628 		/* enable SysErr */
1629 		regmap_write(tc->regmap, INTCTL_G, INT_SYSERR);
1630 
1631 		ret = devm_request_threaded_irq(dev, client->irq,
1632 						NULL, tc_irq_handler,
1633 						IRQF_ONESHOT,
1634 						"tc358767-irq", tc);
1635 		if (ret) {
1636 			dev_err(dev, "failed to register dp interrupt\n");
1637 			return ret;
1638 		}
1639 
1640 		tc->have_irq = true;
1641 	}
1642 
1643 	ret = regmap_read(tc->regmap, TC_IDREG, &tc->rev);
1644 	if (ret) {
1645 		dev_err(tc->dev, "can not read device ID: %d\n", ret);
1646 		return ret;
1647 	}
1648 
1649 	if ((tc->rev != 0x6601) && (tc->rev != 0x6603)) {
1650 		dev_err(tc->dev, "invalid device ID: 0x%08x\n", tc->rev);
1651 		return -EINVAL;
1652 	}
1653 
1654 	tc->assr = (tc->rev == 0x6601); /* Enable ASSR for eDP panels */
1655 
1656 	if (!tc->reset_gpio) {
1657 		/*
1658 		 * If the reset pin isn't present, do a software reset. It isn't
1659 		 * as thorough as the hardware reset, as we can't reset the I2C
1660 		 * communication block for obvious reasons, but it's getting the
1661 		 * chip into a defined state.
1662 		 */
1663 		regmap_update_bits(tc->regmap, SYSRSTENB,
1664 				ENBLCD0 | ENBBM | ENBDSIRX | ENBREG | ENBHDCP,
1665 				0);
1666 		regmap_update_bits(tc->regmap, SYSRSTENB,
1667 				ENBLCD0 | ENBBM | ENBDSIRX | ENBREG | ENBHDCP,
1668 				ENBLCD0 | ENBBM | ENBDSIRX | ENBREG | ENBHDCP);
1669 		usleep_range(5000, 10000);
1670 	}
1671 
1672 	if (tc->hpd_pin >= 0) {
1673 		u32 lcnt_reg = tc->hpd_pin == 0 ? INT_GP0_LCNT : INT_GP1_LCNT;
1674 		u32 h_lc = INT_GPIO_H(tc->hpd_pin) | INT_GPIO_LC(tc->hpd_pin);
1675 
1676 		/* Set LCNT to 2ms */
1677 		regmap_write(tc->regmap, lcnt_reg,
1678 			     clk_get_rate(tc->refclk) * 2 / 1000);
1679 		/* We need the "alternate" mode for HPD */
1680 		regmap_write(tc->regmap, GPIOM, BIT(tc->hpd_pin));
1681 
1682 		if (tc->have_irq) {
1683 			/* enable H & LC */
1684 			regmap_update_bits(tc->regmap, INTCTL_G, h_lc, h_lc);
1685 		}
1686 	}
1687 
1688 	ret = tc_aux_link_setup(tc);
1689 	if (ret)
1690 		return ret;
1691 
1692 	/* Register DP AUX channel */
1693 	tc->aux.name = "TC358767 AUX i2c adapter";
1694 	tc->aux.dev = tc->dev;
1695 	tc->aux.transfer = tc_aux_transfer;
1696 	drm_dp_aux_init(&tc->aux);
1697 
1698 	tc->bridge.funcs = &tc_bridge_funcs;
1699 	if (tc->hpd_pin >= 0)
1700 		tc->bridge.ops |= DRM_BRIDGE_OP_DETECT;
1701 	tc->bridge.ops |= DRM_BRIDGE_OP_EDID;
1702 
1703 	tc->bridge.of_node = dev->of_node;
1704 	drm_bridge_add(&tc->bridge);
1705 
1706 	i2c_set_clientdata(client, tc);
1707 
1708 	return 0;
1709 }
1710 
1711 static int tc_remove(struct i2c_client *client)
1712 {
1713 	struct tc_data *tc = i2c_get_clientdata(client);
1714 
1715 	drm_bridge_remove(&tc->bridge);
1716 
1717 	return 0;
1718 }
1719 
1720 static const struct i2c_device_id tc358767_i2c_ids[] = {
1721 	{ "tc358767", 0 },
1722 	{ }
1723 };
1724 MODULE_DEVICE_TABLE(i2c, tc358767_i2c_ids);
1725 
1726 static const struct of_device_id tc358767_of_ids[] = {
1727 	{ .compatible = "toshiba,tc358767", },
1728 	{ }
1729 };
1730 MODULE_DEVICE_TABLE(of, tc358767_of_ids);
1731 
1732 static struct i2c_driver tc358767_driver = {
1733 	.driver = {
1734 		.name = "tc358767",
1735 		.of_match_table = tc358767_of_ids,
1736 	},
1737 	.id_table = tc358767_i2c_ids,
1738 	.probe = tc_probe,
1739 	.remove	= tc_remove,
1740 };
1741 module_i2c_driver(tc358767_driver);
1742 
1743 MODULE_AUTHOR("Andrey Gusakov <andrey.gusakov@cogentembedded.com>");
1744 MODULE_DESCRIPTION("tc358767 eDP encoder driver");
1745 MODULE_LICENSE("GPL");
1746