xref: /openbmc/linux/drivers/gpu/drm/bridge/tc358767.c (revision 15e3ae36)
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_connector	connector;
248 	struct drm_panel	*panel;
249 
250 	/* link settings */
251 	struct tc_edp_link	link;
252 
253 	/* display edid */
254 	struct edid		*edid;
255 	/* current mode */
256 	struct drm_display_mode	mode;
257 
258 	u32			rev;
259 	u8			assr;
260 
261 	struct gpio_desc	*sd_gpio;
262 	struct gpio_desc	*reset_gpio;
263 	struct clk		*refclk;
264 
265 	/* do we have IRQ */
266 	bool			have_irq;
267 
268 	/* HPD pin number (0 or 1) or -ENODEV */
269 	int			hpd_pin;
270 };
271 
272 static inline struct tc_data *aux_to_tc(struct drm_dp_aux *a)
273 {
274 	return container_of(a, struct tc_data, aux);
275 }
276 
277 static inline struct tc_data *bridge_to_tc(struct drm_bridge *b)
278 {
279 	return container_of(b, struct tc_data, bridge);
280 }
281 
282 static inline struct tc_data *connector_to_tc(struct drm_connector *c)
283 {
284 	return container_of(c, struct tc_data, connector);
285 }
286 
287 static inline int tc_poll_timeout(struct tc_data *tc, unsigned int addr,
288 				  unsigned int cond_mask,
289 				  unsigned int cond_value,
290 				  unsigned long sleep_us, u64 timeout_us)
291 {
292 	unsigned int val;
293 
294 	return regmap_read_poll_timeout(tc->regmap, addr, val,
295 					(val & cond_mask) == cond_value,
296 					sleep_us, timeout_us);
297 }
298 
299 static int tc_aux_wait_busy(struct tc_data *tc)
300 {
301 	return tc_poll_timeout(tc, DP0_AUXSTATUS, AUX_BUSY, 0, 100, 100000);
302 }
303 
304 static int tc_aux_write_data(struct tc_data *tc, const void *data,
305 			     size_t size)
306 {
307 	u32 auxwdata[DP_AUX_MAX_PAYLOAD_BYTES / sizeof(u32)] = { 0 };
308 	int ret, count = ALIGN(size, sizeof(u32));
309 
310 	memcpy(auxwdata, data, size);
311 
312 	ret = regmap_raw_write(tc->regmap, DP0_AUXWDATA(0), auxwdata, count);
313 	if (ret)
314 		return ret;
315 
316 	return size;
317 }
318 
319 static int tc_aux_read_data(struct tc_data *tc, void *data, size_t size)
320 {
321 	u32 auxrdata[DP_AUX_MAX_PAYLOAD_BYTES / sizeof(u32)];
322 	int ret, count = ALIGN(size, sizeof(u32));
323 
324 	ret = regmap_raw_read(tc->regmap, DP0_AUXRDATA(0), auxrdata, count);
325 	if (ret)
326 		return ret;
327 
328 	memcpy(data, auxrdata, size);
329 
330 	return size;
331 }
332 
333 static u32 tc_auxcfg0(struct drm_dp_aux_msg *msg, size_t size)
334 {
335 	u32 auxcfg0 = msg->request;
336 
337 	if (size)
338 		auxcfg0 |= FIELD_PREP(DP0_AUXCFG0_BSIZE, size - 1);
339 	else
340 		auxcfg0 |= DP0_AUXCFG0_ADDR_ONLY;
341 
342 	return auxcfg0;
343 }
344 
345 static ssize_t tc_aux_transfer(struct drm_dp_aux *aux,
346 			       struct drm_dp_aux_msg *msg)
347 {
348 	struct tc_data *tc = aux_to_tc(aux);
349 	size_t size = min_t(size_t, DP_AUX_MAX_PAYLOAD_BYTES - 1, msg->size);
350 	u8 request = msg->request & ~DP_AUX_I2C_MOT;
351 	u32 auxstatus;
352 	int ret;
353 
354 	ret = tc_aux_wait_busy(tc);
355 	if (ret)
356 		return ret;
357 
358 	switch (request) {
359 	case DP_AUX_NATIVE_READ:
360 	case DP_AUX_I2C_READ:
361 		break;
362 	case DP_AUX_NATIVE_WRITE:
363 	case DP_AUX_I2C_WRITE:
364 		if (size) {
365 			ret = tc_aux_write_data(tc, msg->buffer, size);
366 			if (ret < 0)
367 				return ret;
368 		}
369 		break;
370 	default:
371 		return -EINVAL;
372 	}
373 
374 	/* Store address */
375 	ret = regmap_write(tc->regmap, DP0_AUXADDR, msg->address);
376 	if (ret)
377 		return ret;
378 	/* Start transfer */
379 	ret = regmap_write(tc->regmap, DP0_AUXCFG0, tc_auxcfg0(msg, size));
380 	if (ret)
381 		return ret;
382 
383 	ret = tc_aux_wait_busy(tc);
384 	if (ret)
385 		return ret;
386 
387 	ret = regmap_read(tc->regmap, DP0_AUXSTATUS, &auxstatus);
388 	if (ret)
389 		return ret;
390 
391 	if (auxstatus & AUX_TIMEOUT)
392 		return -ETIMEDOUT;
393 	/*
394 	 * For some reason address-only DP_AUX_I2C_WRITE (MOT), still
395 	 * reports 1 byte transferred in its status. To deal we that
396 	 * we ignore aux_bytes field if we know that this was an
397 	 * address-only transfer
398 	 */
399 	if (size)
400 		size = FIELD_GET(AUX_BYTES, auxstatus);
401 	msg->reply = FIELD_GET(AUX_STATUS, auxstatus);
402 
403 	switch (request) {
404 	case DP_AUX_NATIVE_READ:
405 	case DP_AUX_I2C_READ:
406 		if (size)
407 			return tc_aux_read_data(tc, msg->buffer, size);
408 		break;
409 	}
410 
411 	return size;
412 }
413 
414 static const char * const training_pattern1_errors[] = {
415 	"No errors",
416 	"Aux write error",
417 	"Aux read error",
418 	"Max voltage reached error",
419 	"Loop counter expired error",
420 	"res", "res", "res"
421 };
422 
423 static const char * const training_pattern2_errors[] = {
424 	"No errors",
425 	"Aux write error",
426 	"Aux read error",
427 	"Clock recovery failed error",
428 	"Loop counter expired error",
429 	"res", "res", "res"
430 };
431 
432 static u32 tc_srcctrl(struct tc_data *tc)
433 {
434 	/*
435 	 * No training pattern, skew lane 1 data by two LSCLK cycles with
436 	 * respect to lane 0 data, AutoCorrect Mode = 0
437 	 */
438 	u32 reg = DP0_SRCCTRL_NOTP | DP0_SRCCTRL_LANESKEW | DP0_SRCCTRL_EN810B;
439 
440 	if (tc->link.scrambler_dis)
441 		reg |= DP0_SRCCTRL_SCRMBLDIS;	/* Scrambler Disabled */
442 	if (tc->link.spread)
443 		reg |= DP0_SRCCTRL_SSCG;	/* Spread Spectrum Enable */
444 	if (tc->link.num_lanes == 2)
445 		reg |= DP0_SRCCTRL_LANES_2;	/* Two Main Channel Lanes */
446 	if (tc->link.rate != 162000)
447 		reg |= DP0_SRCCTRL_BW27;	/* 2.7 Gbps link */
448 	return reg;
449 }
450 
451 static int tc_pllupdate(struct tc_data *tc, unsigned int pllctrl)
452 {
453 	int ret;
454 
455 	ret = regmap_write(tc->regmap, pllctrl, PLLUPDATE | PLLEN);
456 	if (ret)
457 		return ret;
458 
459 	/* Wait for PLL to lock: up to 2.09 ms, depending on refclk */
460 	usleep_range(3000, 6000);
461 
462 	return 0;
463 }
464 
465 static int tc_pxl_pll_en(struct tc_data *tc, u32 refclk, u32 pixelclock)
466 {
467 	int ret;
468 	int i_pre, best_pre = 1;
469 	int i_post, best_post = 1;
470 	int div, best_div = 1;
471 	int mul, best_mul = 1;
472 	int delta, best_delta;
473 	int ext_div[] = {1, 2, 3, 5, 7};
474 	int best_pixelclock = 0;
475 	int vco_hi = 0;
476 	u32 pxl_pllparam;
477 
478 	dev_dbg(tc->dev, "PLL: requested %d pixelclock, ref %d\n", pixelclock,
479 		refclk);
480 	best_delta = pixelclock;
481 	/* Loop over all possible ext_divs, skipping invalid configurations */
482 	for (i_pre = 0; i_pre < ARRAY_SIZE(ext_div); i_pre++) {
483 		/*
484 		 * refclk / ext_pre_div should be in the 1 to 200 MHz range.
485 		 * We don't allow any refclk > 200 MHz, only check lower bounds.
486 		 */
487 		if (refclk / ext_div[i_pre] < 1000000)
488 			continue;
489 		for (i_post = 0; i_post < ARRAY_SIZE(ext_div); i_post++) {
490 			for (div = 1; div <= 16; div++) {
491 				u32 clk;
492 				u64 tmp;
493 
494 				tmp = pixelclock * ext_div[i_pre] *
495 				      ext_div[i_post] * div;
496 				do_div(tmp, refclk);
497 				mul = tmp;
498 
499 				/* Check limits */
500 				if ((mul < 1) || (mul > 128))
501 					continue;
502 
503 				clk = (refclk / ext_div[i_pre] / div) * mul;
504 				/*
505 				 * refclk * mul / (ext_pre_div * pre_div)
506 				 * should be in the 150 to 650 MHz range
507 				 */
508 				if ((clk > 650000000) || (clk < 150000000))
509 					continue;
510 
511 				clk = clk / ext_div[i_post];
512 				delta = clk - pixelclock;
513 
514 				if (abs(delta) < abs(best_delta)) {
515 					best_pre = i_pre;
516 					best_post = i_post;
517 					best_div = div;
518 					best_mul = mul;
519 					best_delta = delta;
520 					best_pixelclock = clk;
521 				}
522 			}
523 		}
524 	}
525 	if (best_pixelclock == 0) {
526 		dev_err(tc->dev, "Failed to calc clock for %d pixelclock\n",
527 			pixelclock);
528 		return -EINVAL;
529 	}
530 
531 	dev_dbg(tc->dev, "PLL: got %d, delta %d\n", best_pixelclock,
532 		best_delta);
533 	dev_dbg(tc->dev, "PLL: %d / %d / %d * %d / %d\n", refclk,
534 		ext_div[best_pre], best_div, best_mul, ext_div[best_post]);
535 
536 	/* if VCO >= 300 MHz */
537 	if (refclk / ext_div[best_pre] / best_div * best_mul >= 300000000)
538 		vco_hi = 1;
539 	/* see DS */
540 	if (best_div == 16)
541 		best_div = 0;
542 	if (best_mul == 128)
543 		best_mul = 0;
544 
545 	/* Power up PLL and switch to bypass */
546 	ret = regmap_write(tc->regmap, PXL_PLLCTRL, PLLBYP | PLLEN);
547 	if (ret)
548 		return ret;
549 
550 	pxl_pllparam  = vco_hi << 24; /* For PLL VCO >= 300 MHz = 1 */
551 	pxl_pllparam |= ext_div[best_pre] << 20; /* External Pre-divider */
552 	pxl_pllparam |= ext_div[best_post] << 16; /* External Post-divider */
553 	pxl_pllparam |= IN_SEL_REFCLK; /* Use RefClk as PLL input */
554 	pxl_pllparam |= best_div << 8; /* Divider for PLL RefClk */
555 	pxl_pllparam |= best_mul; /* Multiplier for PLL */
556 
557 	ret = regmap_write(tc->regmap, PXL_PLLPARAM, pxl_pllparam);
558 	if (ret)
559 		return ret;
560 
561 	/* Force PLL parameter update and disable bypass */
562 	return tc_pllupdate(tc, PXL_PLLCTRL);
563 }
564 
565 static int tc_pxl_pll_dis(struct tc_data *tc)
566 {
567 	/* Enable PLL bypass, power down PLL */
568 	return regmap_write(tc->regmap, PXL_PLLCTRL, PLLBYP);
569 }
570 
571 static int tc_stream_clock_calc(struct tc_data *tc)
572 {
573 	/*
574 	 * If the Stream clock and Link Symbol clock are
575 	 * asynchronous with each other, the value of M changes over
576 	 * time. This way of generating link clock and stream
577 	 * clock is called Asynchronous Clock mode. The value M
578 	 * must change while the value N stays constant. The
579 	 * value of N in this Asynchronous Clock mode must be set
580 	 * to 2^15 or 32,768.
581 	 *
582 	 * LSCLK = 1/10 of high speed link clock
583 	 *
584 	 * f_STRMCLK = M/N * f_LSCLK
585 	 * M/N = f_STRMCLK / f_LSCLK
586 	 *
587 	 */
588 	return regmap_write(tc->regmap, DP0_VIDMNGEN1, 32768);
589 }
590 
591 static int tc_set_syspllparam(struct tc_data *tc)
592 {
593 	unsigned long rate;
594 	u32 pllparam = SYSCLK_SEL_LSCLK | LSCLK_DIV_2;
595 
596 	rate = clk_get_rate(tc->refclk);
597 	switch (rate) {
598 	case 38400000:
599 		pllparam |= REF_FREQ_38M4;
600 		break;
601 	case 26000000:
602 		pllparam |= REF_FREQ_26M;
603 		break;
604 	case 19200000:
605 		pllparam |= REF_FREQ_19M2;
606 		break;
607 	case 13000000:
608 		pllparam |= REF_FREQ_13M;
609 		break;
610 	default:
611 		dev_err(tc->dev, "Invalid refclk rate: %lu Hz\n", rate);
612 		return -EINVAL;
613 	}
614 
615 	return regmap_write(tc->regmap, SYS_PLLPARAM, pllparam);
616 }
617 
618 static int tc_aux_link_setup(struct tc_data *tc)
619 {
620 	int ret;
621 	u32 dp0_auxcfg1;
622 
623 	/* Setup DP-PHY / PLL */
624 	ret = tc_set_syspllparam(tc);
625 	if (ret)
626 		goto err;
627 
628 	ret = regmap_write(tc->regmap, DP_PHY_CTRL,
629 			   BGREN | PWR_SW_EN | PHY_A0_EN);
630 	if (ret)
631 		goto err;
632 	/*
633 	 * Initially PLLs are in bypass. Force PLL parameter update,
634 	 * disable PLL bypass, enable PLL
635 	 */
636 	ret = tc_pllupdate(tc, DP0_PLLCTRL);
637 	if (ret)
638 		goto err;
639 
640 	ret = tc_pllupdate(tc, DP1_PLLCTRL);
641 	if (ret)
642 		goto err;
643 
644 	ret = tc_poll_timeout(tc, DP_PHY_CTRL, PHY_RDY, PHY_RDY, 100, 100000);
645 	if (ret == -ETIMEDOUT) {
646 		dev_err(tc->dev, "Timeout waiting for PHY to become ready");
647 		return ret;
648 	} else if (ret) {
649 		goto err;
650 	}
651 
652 	/* Setup AUX link */
653 	dp0_auxcfg1  = AUX_RX_FILTER_EN;
654 	dp0_auxcfg1 |= 0x06 << 8; /* Aux Bit Period Calculator Threshold */
655 	dp0_auxcfg1 |= 0x3f << 0; /* Aux Response Timeout Timer */
656 
657 	ret = regmap_write(tc->regmap, DP0_AUXCFG1, dp0_auxcfg1);
658 	if (ret)
659 		goto err;
660 
661 	return 0;
662 err:
663 	dev_err(tc->dev, "tc_aux_link_setup failed: %d\n", ret);
664 	return ret;
665 }
666 
667 static int tc_get_display_props(struct tc_data *tc)
668 {
669 	u8 revision, num_lanes;
670 	unsigned int rate;
671 	int ret;
672 	u8 reg;
673 
674 	/* Read DP Rx Link Capability */
675 	ret = drm_dp_dpcd_read(&tc->aux, DP_DPCD_REV, tc->link.dpcd,
676 			       DP_RECEIVER_CAP_SIZE);
677 	if (ret < 0)
678 		goto err_dpcd_read;
679 
680 	revision = tc->link.dpcd[DP_DPCD_REV];
681 	rate = drm_dp_max_link_rate(tc->link.dpcd);
682 	num_lanes = drm_dp_max_lane_count(tc->link.dpcd);
683 
684 	if (rate != 162000 && rate != 270000) {
685 		dev_dbg(tc->dev, "Falling to 2.7 Gbps rate\n");
686 		rate = 270000;
687 	}
688 
689 	tc->link.rate = rate;
690 
691 	if (num_lanes > 2) {
692 		dev_dbg(tc->dev, "Falling to 2 lanes\n");
693 		num_lanes = 2;
694 	}
695 
696 	tc->link.num_lanes = num_lanes;
697 
698 	ret = drm_dp_dpcd_readb(&tc->aux, DP_MAX_DOWNSPREAD, &reg);
699 	if (ret < 0)
700 		goto err_dpcd_read;
701 	tc->link.spread = reg & DP_MAX_DOWNSPREAD_0_5;
702 
703 	ret = drm_dp_dpcd_readb(&tc->aux, DP_MAIN_LINK_CHANNEL_CODING, &reg);
704 	if (ret < 0)
705 		goto err_dpcd_read;
706 
707 	tc->link.scrambler_dis = false;
708 	/* read assr */
709 	ret = drm_dp_dpcd_readb(&tc->aux, DP_EDP_CONFIGURATION_SET, &reg);
710 	if (ret < 0)
711 		goto err_dpcd_read;
712 	tc->link.assr = reg & DP_ALTERNATE_SCRAMBLER_RESET_ENABLE;
713 
714 	dev_dbg(tc->dev, "DPCD rev: %d.%d, rate: %s, lanes: %d, framing: %s\n",
715 		revision >> 4, revision & 0x0f,
716 		(tc->link.rate == 162000) ? "1.62Gbps" : "2.7Gbps",
717 		tc->link.num_lanes,
718 		drm_dp_enhanced_frame_cap(tc->link.dpcd) ?
719 		"enhanced" : "default");
720 	dev_dbg(tc->dev, "Downspread: %s, scrambler: %s\n",
721 		tc->link.spread ? "0.5%" : "0.0%",
722 		tc->link.scrambler_dis ? "disabled" : "enabled");
723 	dev_dbg(tc->dev, "Display ASSR: %d, TC358767 ASSR: %d\n",
724 		tc->link.assr, tc->assr);
725 
726 	return 0;
727 
728 err_dpcd_read:
729 	dev_err(tc->dev, "failed to read DPCD: %d\n", ret);
730 	return ret;
731 }
732 
733 static int tc_set_video_mode(struct tc_data *tc,
734 			     const struct drm_display_mode *mode)
735 {
736 	int ret;
737 	int vid_sync_dly;
738 	int max_tu_symbol;
739 
740 	int left_margin = mode->htotal - mode->hsync_end;
741 	int right_margin = mode->hsync_start - mode->hdisplay;
742 	int hsync_len = mode->hsync_end - mode->hsync_start;
743 	int upper_margin = mode->vtotal - mode->vsync_end;
744 	int lower_margin = mode->vsync_start - mode->vdisplay;
745 	int vsync_len = mode->vsync_end - mode->vsync_start;
746 	u32 dp0_syncval;
747 	u32 bits_per_pixel = 24;
748 	u32 in_bw, out_bw;
749 
750 	/*
751 	 * Recommended maximum number of symbols transferred in a transfer unit:
752 	 * DIV_ROUND_UP((input active video bandwidth in bytes) * tu_size,
753 	 *              (output active video bandwidth in bytes))
754 	 * Must be less than tu_size.
755 	 */
756 
757 	in_bw = mode->clock * bits_per_pixel / 8;
758 	out_bw = tc->link.num_lanes * tc->link.rate;
759 	max_tu_symbol = DIV_ROUND_UP(in_bw * TU_SIZE_RECOMMENDED, out_bw);
760 
761 	dev_dbg(tc->dev, "set mode %dx%d\n",
762 		mode->hdisplay, mode->vdisplay);
763 	dev_dbg(tc->dev, "H margin %d,%d sync %d\n",
764 		left_margin, right_margin, hsync_len);
765 	dev_dbg(tc->dev, "V margin %d,%d sync %d\n",
766 		upper_margin, lower_margin, vsync_len);
767 	dev_dbg(tc->dev, "total: %dx%d\n", mode->htotal, mode->vtotal);
768 
769 
770 	/*
771 	 * LCD Ctl Frame Size
772 	 * datasheet is not clear of vsdelay in case of DPI
773 	 * assume we do not need any delay when DPI is a source of
774 	 * sync signals
775 	 */
776 	ret = regmap_write(tc->regmap, VPCTRL0,
777 			   FIELD_PREP(VSDELAY, 0) |
778 			   OPXLFMT_RGB888 | FRMSYNC_DISABLED | MSF_DISABLED);
779 	if (ret)
780 		return ret;
781 
782 	ret = regmap_write(tc->regmap, HTIM01,
783 			   FIELD_PREP(HBPR, ALIGN(left_margin, 2)) |
784 			   FIELD_PREP(HPW, ALIGN(hsync_len, 2)));
785 	if (ret)
786 		return ret;
787 
788 	ret = regmap_write(tc->regmap, HTIM02,
789 			   FIELD_PREP(HDISPR, ALIGN(mode->hdisplay, 2)) |
790 			   FIELD_PREP(HFPR, ALIGN(right_margin, 2)));
791 	if (ret)
792 		return ret;
793 
794 	ret = regmap_write(tc->regmap, VTIM01,
795 			   FIELD_PREP(VBPR, upper_margin) |
796 			   FIELD_PREP(VSPR, vsync_len));
797 	if (ret)
798 		return ret;
799 
800 	ret = regmap_write(tc->regmap, VTIM02,
801 			   FIELD_PREP(VFPR, lower_margin) |
802 			   FIELD_PREP(VDISPR, mode->vdisplay));
803 	if (ret)
804 		return ret;
805 
806 	ret = regmap_write(tc->regmap, VFUEN0, VFUEN); /* update settings */
807 	if (ret)
808 		return ret;
809 
810 	/* Test pattern settings */
811 	ret = regmap_write(tc->regmap, TSTCTL,
812 			   FIELD_PREP(COLOR_R, 120) |
813 			   FIELD_PREP(COLOR_G, 20) |
814 			   FIELD_PREP(COLOR_B, 99) |
815 			   ENI2CFILTER |
816 			   FIELD_PREP(COLOR_BAR_MODE, COLOR_BAR_MODE_BARS));
817 	if (ret)
818 		return ret;
819 
820 	/* DP Main Stream Attributes */
821 	vid_sync_dly = hsync_len + left_margin + mode->hdisplay;
822 	ret = regmap_write(tc->regmap, DP0_VIDSYNCDELAY,
823 		 FIELD_PREP(THRESH_DLY, max_tu_symbol) |
824 		 FIELD_PREP(VID_SYNC_DLY, vid_sync_dly));
825 
826 	ret = regmap_write(tc->regmap, DP0_TOTALVAL,
827 			   FIELD_PREP(H_TOTAL, mode->htotal) |
828 			   FIELD_PREP(V_TOTAL, mode->vtotal));
829 	if (ret)
830 		return ret;
831 
832 	ret = regmap_write(tc->regmap, DP0_STARTVAL,
833 			   FIELD_PREP(H_START, left_margin + hsync_len) |
834 			   FIELD_PREP(V_START, upper_margin + vsync_len));
835 	if (ret)
836 		return ret;
837 
838 	ret = regmap_write(tc->regmap, DP0_ACTIVEVAL,
839 			   FIELD_PREP(V_ACT, mode->vdisplay) |
840 			   FIELD_PREP(H_ACT, mode->hdisplay));
841 	if (ret)
842 		return ret;
843 
844 	dp0_syncval = FIELD_PREP(VS_WIDTH, vsync_len) |
845 		      FIELD_PREP(HS_WIDTH, hsync_len);
846 
847 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
848 		dp0_syncval |= SYNCVAL_VS_POL_ACTIVE_LOW;
849 
850 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
851 		dp0_syncval |= SYNCVAL_HS_POL_ACTIVE_LOW;
852 
853 	ret = regmap_write(tc->regmap, DP0_SYNCVAL, dp0_syncval);
854 	if (ret)
855 		return ret;
856 
857 	ret = regmap_write(tc->regmap, DPIPXLFMT,
858 			   VS_POL_ACTIVE_LOW | HS_POL_ACTIVE_LOW |
859 			   DE_POL_ACTIVE_HIGH | SUB_CFG_TYPE_CONFIG1 |
860 			   DPI_BPP_RGB888);
861 	if (ret)
862 		return ret;
863 
864 	ret = regmap_write(tc->regmap, DP0_MISC,
865 			   FIELD_PREP(MAX_TU_SYMBOL, max_tu_symbol) |
866 			   FIELD_PREP(TU_SIZE, TU_SIZE_RECOMMENDED) |
867 			   BPC_8);
868 	if (ret)
869 		return ret;
870 
871 	return 0;
872 }
873 
874 static int tc_wait_link_training(struct tc_data *tc)
875 {
876 	u32 value;
877 	int ret;
878 
879 	ret = tc_poll_timeout(tc, DP0_LTSTAT, LT_LOOPDONE,
880 			      LT_LOOPDONE, 500, 100000);
881 	if (ret) {
882 		dev_err(tc->dev, "Link training timeout waiting for LT_LOOPDONE!\n");
883 		return ret;
884 	}
885 
886 	ret = regmap_read(tc->regmap, DP0_LTSTAT, &value);
887 	if (ret)
888 		return ret;
889 
890 	return (value >> 8) & 0x7;
891 }
892 
893 static int tc_main_link_enable(struct tc_data *tc)
894 {
895 	struct drm_dp_aux *aux = &tc->aux;
896 	struct device *dev = tc->dev;
897 	u32 dp_phy_ctrl;
898 	u32 value;
899 	int ret;
900 	u8 tmp[DP_LINK_STATUS_SIZE];
901 
902 	dev_dbg(tc->dev, "link enable\n");
903 
904 	ret = regmap_read(tc->regmap, DP0CTL, &value);
905 	if (ret)
906 		return ret;
907 
908 	if (WARN_ON(value & DP_EN)) {
909 		ret = regmap_write(tc->regmap, DP0CTL, 0);
910 		if (ret)
911 			return ret;
912 	}
913 
914 	ret = regmap_write(tc->regmap, DP0_SRCCTRL, tc_srcctrl(tc));
915 	if (ret)
916 		return ret;
917 	/* SSCG and BW27 on DP1 must be set to the same as on DP0 */
918 	ret = regmap_write(tc->regmap, DP1_SRCCTRL,
919 		 (tc->link.spread ? DP0_SRCCTRL_SSCG : 0) |
920 		 ((tc->link.rate != 162000) ? DP0_SRCCTRL_BW27 : 0));
921 	if (ret)
922 		return ret;
923 
924 	ret = tc_set_syspllparam(tc);
925 	if (ret)
926 		return ret;
927 
928 	/* Setup Main Link */
929 	dp_phy_ctrl = BGREN | PWR_SW_EN | PHY_A0_EN | PHY_M0_EN;
930 	if (tc->link.num_lanes == 2)
931 		dp_phy_ctrl |= PHY_2LANE;
932 
933 	ret = regmap_write(tc->regmap, DP_PHY_CTRL, dp_phy_ctrl);
934 	if (ret)
935 		return ret;
936 
937 	/* PLL setup */
938 	ret = tc_pllupdate(tc, DP0_PLLCTRL);
939 	if (ret)
940 		return ret;
941 
942 	ret = tc_pllupdate(tc, DP1_PLLCTRL);
943 	if (ret)
944 		return ret;
945 
946 	/* Reset/Enable Main Links */
947 	dp_phy_ctrl |= DP_PHY_RST | PHY_M1_RST | PHY_M0_RST;
948 	ret = regmap_write(tc->regmap, DP_PHY_CTRL, dp_phy_ctrl);
949 	usleep_range(100, 200);
950 	dp_phy_ctrl &= ~(DP_PHY_RST | PHY_M1_RST | PHY_M0_RST);
951 	ret = regmap_write(tc->regmap, DP_PHY_CTRL, dp_phy_ctrl);
952 
953 	ret = tc_poll_timeout(tc, DP_PHY_CTRL, PHY_RDY, PHY_RDY, 500, 100000);
954 	if (ret) {
955 		dev_err(dev, "timeout waiting for phy become ready");
956 		return ret;
957 	}
958 
959 	/* Set misc: 8 bits per color */
960 	ret = regmap_update_bits(tc->regmap, DP0_MISC, BPC_8, BPC_8);
961 	if (ret)
962 		return ret;
963 
964 	/*
965 	 * ASSR mode
966 	 * on TC358767 side ASSR configured through strap pin
967 	 * seems there is no way to change this setting from SW
968 	 *
969 	 * check is tc configured for same mode
970 	 */
971 	if (tc->assr != tc->link.assr) {
972 		dev_dbg(dev, "Trying to set display to ASSR: %d\n",
973 			tc->assr);
974 		/* try to set ASSR on display side */
975 		tmp[0] = tc->assr;
976 		ret = drm_dp_dpcd_writeb(aux, DP_EDP_CONFIGURATION_SET, tmp[0]);
977 		if (ret < 0)
978 			goto err_dpcd_read;
979 		/* read back */
980 		ret = drm_dp_dpcd_readb(aux, DP_EDP_CONFIGURATION_SET, tmp);
981 		if (ret < 0)
982 			goto err_dpcd_read;
983 
984 		if (tmp[0] != tc->assr) {
985 			dev_dbg(dev, "Failed to switch display ASSR to %d, falling back to unscrambled mode\n",
986 				tc->assr);
987 			/* trying with disabled scrambler */
988 			tc->link.scrambler_dis = true;
989 		}
990 	}
991 
992 	/* Setup Link & DPRx Config for Training */
993 	tmp[0] = drm_dp_link_rate_to_bw_code(tc->link.rate);
994 	tmp[1] = tc->link.num_lanes;
995 
996 	if (drm_dp_enhanced_frame_cap(tc->link.dpcd))
997 		tmp[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
998 
999 	ret = drm_dp_dpcd_write(aux, DP_LINK_BW_SET, tmp, 2);
1000 	if (ret < 0)
1001 		goto err_dpcd_write;
1002 
1003 	/* DOWNSPREAD_CTRL */
1004 	tmp[0] = tc->link.spread ? DP_SPREAD_AMP_0_5 : 0x00;
1005 	/* MAIN_LINK_CHANNEL_CODING_SET */
1006 	tmp[1] =  DP_SET_ANSI_8B10B;
1007 	ret = drm_dp_dpcd_write(aux, DP_DOWNSPREAD_CTRL, tmp, 2);
1008 	if (ret < 0)
1009 		goto err_dpcd_write;
1010 
1011 	/* Reset voltage-swing & pre-emphasis */
1012 	tmp[0] = tmp[1] = DP_TRAIN_VOLTAGE_SWING_LEVEL_0 |
1013 			  DP_TRAIN_PRE_EMPH_LEVEL_0;
1014 	ret = drm_dp_dpcd_write(aux, DP_TRAINING_LANE0_SET, tmp, 2);
1015 	if (ret < 0)
1016 		goto err_dpcd_write;
1017 
1018 	/* Clock-Recovery */
1019 
1020 	/* Set DPCD 0x102 for Training Pattern 1 */
1021 	ret = regmap_write(tc->regmap, DP0_SNKLTCTRL,
1022 			   DP_LINK_SCRAMBLING_DISABLE |
1023 			   DP_TRAINING_PATTERN_1);
1024 	if (ret)
1025 		return ret;
1026 
1027 	ret = regmap_write(tc->regmap, DP0_LTLOOPCTRL,
1028 			   (15 << 28) |	/* Defer Iteration Count */
1029 			   (15 << 24) |	/* Loop Iteration Count */
1030 			   (0xd << 0));	/* Loop Timer Delay */
1031 	if (ret)
1032 		return ret;
1033 
1034 	ret = regmap_write(tc->regmap, DP0_SRCCTRL,
1035 			   tc_srcctrl(tc) | DP0_SRCCTRL_SCRMBLDIS |
1036 			   DP0_SRCCTRL_AUTOCORRECT |
1037 			   DP0_SRCCTRL_TP1);
1038 	if (ret)
1039 		return ret;
1040 
1041 	/* Enable DP0 to start Link Training */
1042 	ret = regmap_write(tc->regmap, DP0CTL,
1043 			   (drm_dp_enhanced_frame_cap(tc->link.dpcd) ?
1044 				EF_EN : 0) | DP_EN);
1045 	if (ret)
1046 		return ret;
1047 
1048 	/* wait */
1049 
1050 	ret = tc_wait_link_training(tc);
1051 	if (ret < 0)
1052 		return ret;
1053 
1054 	if (ret) {
1055 		dev_err(tc->dev, "Link training phase 1 failed: %s\n",
1056 			training_pattern1_errors[ret]);
1057 		return -ENODEV;
1058 	}
1059 
1060 	/* Channel Equalization */
1061 
1062 	/* Set DPCD 0x102 for Training Pattern 2 */
1063 	ret = regmap_write(tc->regmap, DP0_SNKLTCTRL,
1064 			   DP_LINK_SCRAMBLING_DISABLE |
1065 			   DP_TRAINING_PATTERN_2);
1066 	if (ret)
1067 		return ret;
1068 
1069 	ret = regmap_write(tc->regmap, DP0_SRCCTRL,
1070 			   tc_srcctrl(tc) | DP0_SRCCTRL_SCRMBLDIS |
1071 			   DP0_SRCCTRL_AUTOCORRECT |
1072 			   DP0_SRCCTRL_TP2);
1073 	if (ret)
1074 		return ret;
1075 
1076 	/* wait */
1077 	ret = tc_wait_link_training(tc);
1078 	if (ret < 0)
1079 		return ret;
1080 
1081 	if (ret) {
1082 		dev_err(tc->dev, "Link training phase 2 failed: %s\n",
1083 			training_pattern2_errors[ret]);
1084 		return -ENODEV;
1085 	}
1086 
1087 	/*
1088 	 * Toshiba's documentation suggests to first clear DPCD 0x102, then
1089 	 * clear the training pattern bit in DP0_SRCCTRL. Testing shows
1090 	 * that the link sometimes drops if those steps are done in that order,
1091 	 * but if the steps are done in reverse order, the link stays up.
1092 	 *
1093 	 * So we do the steps differently than documented here.
1094 	 */
1095 
1096 	/* Clear Training Pattern, set AutoCorrect Mode = 1 */
1097 	ret = regmap_write(tc->regmap, DP0_SRCCTRL, tc_srcctrl(tc) |
1098 			   DP0_SRCCTRL_AUTOCORRECT);
1099 	if (ret)
1100 		return ret;
1101 
1102 	/* Clear DPCD 0x102 */
1103 	/* Note: Can Not use DP0_SNKLTCTRL (0x06E4) short cut */
1104 	tmp[0] = tc->link.scrambler_dis ? DP_LINK_SCRAMBLING_DISABLE : 0x00;
1105 	ret = drm_dp_dpcd_writeb(aux, DP_TRAINING_PATTERN_SET, tmp[0]);
1106 	if (ret < 0)
1107 		goto err_dpcd_write;
1108 
1109 	/* Check link status */
1110 	ret = drm_dp_dpcd_read_link_status(aux, tmp);
1111 	if (ret < 0)
1112 		goto err_dpcd_read;
1113 
1114 	ret = 0;
1115 
1116 	value = tmp[0] & DP_CHANNEL_EQ_BITS;
1117 
1118 	if (value != DP_CHANNEL_EQ_BITS) {
1119 		dev_err(tc->dev, "Lane 0 failed: %x\n", value);
1120 		ret = -ENODEV;
1121 	}
1122 
1123 	if (tc->link.num_lanes == 2) {
1124 		value = (tmp[0] >> 4) & DP_CHANNEL_EQ_BITS;
1125 
1126 		if (value != DP_CHANNEL_EQ_BITS) {
1127 			dev_err(tc->dev, "Lane 1 failed: %x\n", value);
1128 			ret = -ENODEV;
1129 		}
1130 
1131 		if (!(tmp[2] & DP_INTERLANE_ALIGN_DONE)) {
1132 			dev_err(tc->dev, "Interlane align failed\n");
1133 			ret = -ENODEV;
1134 		}
1135 	}
1136 
1137 	if (ret) {
1138 		dev_err(dev, "0x0202 LANE0_1_STATUS:            0x%02x\n", tmp[0]);
1139 		dev_err(dev, "0x0203 LANE2_3_STATUS             0x%02x\n", tmp[1]);
1140 		dev_err(dev, "0x0204 LANE_ALIGN_STATUS_UPDATED: 0x%02x\n", tmp[2]);
1141 		dev_err(dev, "0x0205 SINK_STATUS:               0x%02x\n", tmp[3]);
1142 		dev_err(dev, "0x0206 ADJUST_REQUEST_LANE0_1:    0x%02x\n", tmp[4]);
1143 		dev_err(dev, "0x0207 ADJUST_REQUEST_LANE2_3:    0x%02x\n", tmp[5]);
1144 		return ret;
1145 	}
1146 
1147 	return 0;
1148 err_dpcd_read:
1149 	dev_err(tc->dev, "Failed to read DPCD: %d\n", ret);
1150 	return ret;
1151 err_dpcd_write:
1152 	dev_err(tc->dev, "Failed to write DPCD: %d\n", ret);
1153 	return ret;
1154 }
1155 
1156 static int tc_main_link_disable(struct tc_data *tc)
1157 {
1158 	int ret;
1159 
1160 	dev_dbg(tc->dev, "link disable\n");
1161 
1162 	ret = regmap_write(tc->regmap, DP0_SRCCTRL, 0);
1163 	if (ret)
1164 		return ret;
1165 
1166 	return regmap_write(tc->regmap, DP0CTL, 0);
1167 }
1168 
1169 static int tc_stream_enable(struct tc_data *tc)
1170 {
1171 	int ret;
1172 	u32 value;
1173 
1174 	dev_dbg(tc->dev, "enable video stream\n");
1175 
1176 	/* PXL PLL setup */
1177 	if (tc_test_pattern) {
1178 		ret = tc_pxl_pll_en(tc, clk_get_rate(tc->refclk),
1179 				    1000 * tc->mode.clock);
1180 		if (ret)
1181 			return ret;
1182 	}
1183 
1184 	ret = tc_set_video_mode(tc, &tc->mode);
1185 	if (ret)
1186 		return ret;
1187 
1188 	/* Set M/N */
1189 	ret = tc_stream_clock_calc(tc);
1190 	if (ret)
1191 		return ret;
1192 
1193 	value = VID_MN_GEN | DP_EN;
1194 	if (drm_dp_enhanced_frame_cap(tc->link.dpcd))
1195 		value |= EF_EN;
1196 	ret = regmap_write(tc->regmap, DP0CTL, value);
1197 	if (ret)
1198 		return ret;
1199 	/*
1200 	 * VID_EN assertion should be delayed by at least N * LSCLK
1201 	 * cycles from the time VID_MN_GEN is enabled in order to
1202 	 * generate stable values for VID_M. LSCLK is 270 MHz or
1203 	 * 162 MHz, VID_N is set to 32768 in  tc_stream_clock_calc(),
1204 	 * so a delay of at least 203 us should suffice.
1205 	 */
1206 	usleep_range(500, 1000);
1207 	value |= VID_EN;
1208 	ret = regmap_write(tc->regmap, DP0CTL, value);
1209 	if (ret)
1210 		return ret;
1211 	/* Set input interface */
1212 	value = DP0_AUDSRC_NO_INPUT;
1213 	if (tc_test_pattern)
1214 		value |= DP0_VIDSRC_COLOR_BAR;
1215 	else
1216 		value |= DP0_VIDSRC_DPI_RX;
1217 	ret = regmap_write(tc->regmap, SYSCTRL, value);
1218 	if (ret)
1219 		return ret;
1220 
1221 	return 0;
1222 }
1223 
1224 static int tc_stream_disable(struct tc_data *tc)
1225 {
1226 	int ret;
1227 
1228 	dev_dbg(tc->dev, "disable video stream\n");
1229 
1230 	ret = regmap_update_bits(tc->regmap, DP0CTL, VID_EN, 0);
1231 	if (ret)
1232 		return ret;
1233 
1234 	tc_pxl_pll_dis(tc);
1235 
1236 	return 0;
1237 }
1238 
1239 static void tc_bridge_pre_enable(struct drm_bridge *bridge)
1240 {
1241 	struct tc_data *tc = bridge_to_tc(bridge);
1242 
1243 	drm_panel_prepare(tc->panel);
1244 }
1245 
1246 static void tc_bridge_enable(struct drm_bridge *bridge)
1247 {
1248 	struct tc_data *tc = bridge_to_tc(bridge);
1249 	int ret;
1250 
1251 	ret = tc_get_display_props(tc);
1252 	if (ret < 0) {
1253 		dev_err(tc->dev, "failed to read display props: %d\n", ret);
1254 		return;
1255 	}
1256 
1257 	ret = tc_main_link_enable(tc);
1258 	if (ret < 0) {
1259 		dev_err(tc->dev, "main link enable error: %d\n", ret);
1260 		return;
1261 	}
1262 
1263 	ret = tc_stream_enable(tc);
1264 	if (ret < 0) {
1265 		dev_err(tc->dev, "main link stream start error: %d\n", ret);
1266 		tc_main_link_disable(tc);
1267 		return;
1268 	}
1269 
1270 	drm_panel_enable(tc->panel);
1271 }
1272 
1273 static void tc_bridge_disable(struct drm_bridge *bridge)
1274 {
1275 	struct tc_data *tc = bridge_to_tc(bridge);
1276 	int ret;
1277 
1278 	drm_panel_disable(tc->panel);
1279 
1280 	ret = tc_stream_disable(tc);
1281 	if (ret < 0)
1282 		dev_err(tc->dev, "main link stream stop error: %d\n", ret);
1283 
1284 	ret = tc_main_link_disable(tc);
1285 	if (ret < 0)
1286 		dev_err(tc->dev, "main link disable error: %d\n", ret);
1287 }
1288 
1289 static void tc_bridge_post_disable(struct drm_bridge *bridge)
1290 {
1291 	struct tc_data *tc = bridge_to_tc(bridge);
1292 
1293 	drm_panel_unprepare(tc->panel);
1294 }
1295 
1296 static bool tc_bridge_mode_fixup(struct drm_bridge *bridge,
1297 				 const struct drm_display_mode *mode,
1298 				 struct drm_display_mode *adj)
1299 {
1300 	/* Fixup sync polarities, both hsync and vsync are active low */
1301 	adj->flags = mode->flags;
1302 	adj->flags |= (DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC);
1303 	adj->flags &= ~(DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC);
1304 
1305 	return true;
1306 }
1307 
1308 static enum drm_mode_status tc_mode_valid(struct drm_bridge *bridge,
1309 					  const struct drm_display_mode *mode)
1310 {
1311 	struct tc_data *tc = bridge_to_tc(bridge);
1312 	u32 req, avail;
1313 	u32 bits_per_pixel = 24;
1314 
1315 	/* DPI interface clock limitation: upto 154 MHz */
1316 	if (mode->clock > 154000)
1317 		return MODE_CLOCK_HIGH;
1318 
1319 	req = mode->clock * bits_per_pixel / 8;
1320 	avail = tc->link.num_lanes * tc->link.rate;
1321 
1322 	if (req > avail)
1323 		return MODE_BAD;
1324 
1325 	return MODE_OK;
1326 }
1327 
1328 static void tc_bridge_mode_set(struct drm_bridge *bridge,
1329 			       const struct drm_display_mode *mode,
1330 			       const struct drm_display_mode *adj)
1331 {
1332 	struct tc_data *tc = bridge_to_tc(bridge);
1333 
1334 	tc->mode = *mode;
1335 }
1336 
1337 static int tc_connector_get_modes(struct drm_connector *connector)
1338 {
1339 	struct tc_data *tc = connector_to_tc(connector);
1340 	struct edid *edid;
1341 	int count;
1342 	int ret;
1343 
1344 	ret = tc_get_display_props(tc);
1345 	if (ret < 0) {
1346 		dev_err(tc->dev, "failed to read display props: %d\n", ret);
1347 		return 0;
1348 	}
1349 
1350 	count = drm_panel_get_modes(tc->panel, connector);
1351 	if (count > 0)
1352 		return count;
1353 
1354 	edid = drm_get_edid(connector, &tc->aux.ddc);
1355 
1356 	kfree(tc->edid);
1357 	tc->edid = edid;
1358 	if (!edid)
1359 		return 0;
1360 
1361 	drm_connector_update_edid_property(connector, edid);
1362 	count = drm_add_edid_modes(connector, edid);
1363 
1364 	return count;
1365 }
1366 
1367 static const struct drm_connector_helper_funcs tc_connector_helper_funcs = {
1368 	.get_modes = tc_connector_get_modes,
1369 };
1370 
1371 static enum drm_connector_status tc_connector_detect(struct drm_connector *connector,
1372 						     bool force)
1373 {
1374 	struct tc_data *tc = connector_to_tc(connector);
1375 	bool conn;
1376 	u32 val;
1377 	int ret;
1378 
1379 	if (tc->hpd_pin < 0) {
1380 		if (tc->panel)
1381 			return connector_status_connected;
1382 		else
1383 			return connector_status_unknown;
1384 	}
1385 
1386 	ret = regmap_read(tc->regmap, GPIOI, &val);
1387 	if (ret)
1388 		return connector_status_unknown;
1389 
1390 	conn = val & BIT(tc->hpd_pin);
1391 
1392 	if (conn)
1393 		return connector_status_connected;
1394 	else
1395 		return connector_status_disconnected;
1396 }
1397 
1398 static const struct drm_connector_funcs tc_connector_funcs = {
1399 	.detect = tc_connector_detect,
1400 	.fill_modes = drm_helper_probe_single_connector_modes,
1401 	.destroy = drm_connector_cleanup,
1402 	.reset = drm_atomic_helper_connector_reset,
1403 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
1404 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
1405 };
1406 
1407 static int tc_bridge_attach(struct drm_bridge *bridge,
1408 			    enum drm_bridge_attach_flags flags)
1409 {
1410 	u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
1411 	struct tc_data *tc = bridge_to_tc(bridge);
1412 	struct drm_device *drm = bridge->dev;
1413 	int ret;
1414 
1415 	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
1416 		DRM_ERROR("Fix bridge driver to make connector optional!");
1417 		return -EINVAL;
1418 	}
1419 
1420 	/* Create DP/eDP connector */
1421 	drm_connector_helper_add(&tc->connector, &tc_connector_helper_funcs);
1422 	ret = drm_connector_init(drm, &tc->connector, &tc_connector_funcs,
1423 				 tc->panel ? DRM_MODE_CONNECTOR_eDP :
1424 				 DRM_MODE_CONNECTOR_DisplayPort);
1425 	if (ret)
1426 		return ret;
1427 
1428 	/* Don't poll if don't have HPD connected */
1429 	if (tc->hpd_pin >= 0) {
1430 		if (tc->have_irq)
1431 			tc->connector.polled = DRM_CONNECTOR_POLL_HPD;
1432 		else
1433 			tc->connector.polled = DRM_CONNECTOR_POLL_CONNECT |
1434 					       DRM_CONNECTOR_POLL_DISCONNECT;
1435 	}
1436 
1437 	if (tc->panel)
1438 		drm_panel_attach(tc->panel, &tc->connector);
1439 
1440 	drm_display_info_set_bus_formats(&tc->connector.display_info,
1441 					 &bus_format, 1);
1442 	tc->connector.display_info.bus_flags =
1443 		DRM_BUS_FLAG_DE_HIGH |
1444 		DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE |
1445 		DRM_BUS_FLAG_SYNC_DRIVE_NEGEDGE;
1446 	drm_connector_attach_encoder(&tc->connector, tc->bridge.encoder);
1447 
1448 	return 0;
1449 }
1450 
1451 static const struct drm_bridge_funcs tc_bridge_funcs = {
1452 	.attach = tc_bridge_attach,
1453 	.mode_valid = tc_mode_valid,
1454 	.mode_set = tc_bridge_mode_set,
1455 	.pre_enable = tc_bridge_pre_enable,
1456 	.enable = tc_bridge_enable,
1457 	.disable = tc_bridge_disable,
1458 	.post_disable = tc_bridge_post_disable,
1459 	.mode_fixup = tc_bridge_mode_fixup,
1460 };
1461 
1462 static bool tc_readable_reg(struct device *dev, unsigned int reg)
1463 {
1464 	return reg != SYSCTRL;
1465 }
1466 
1467 static const struct regmap_range tc_volatile_ranges[] = {
1468 	regmap_reg_range(DP0_AUXWDATA(0), DP0_AUXSTATUS),
1469 	regmap_reg_range(DP0_LTSTAT, DP0_SNKLTCHGREQ),
1470 	regmap_reg_range(DP_PHY_CTRL, DP_PHY_CTRL),
1471 	regmap_reg_range(DP0_PLLCTRL, PXL_PLLCTRL),
1472 	regmap_reg_range(VFUEN0, VFUEN0),
1473 	regmap_reg_range(INTSTS_G, INTSTS_G),
1474 	regmap_reg_range(GPIOI, GPIOI),
1475 };
1476 
1477 static const struct regmap_access_table tc_volatile_table = {
1478 	.yes_ranges = tc_volatile_ranges,
1479 	.n_yes_ranges = ARRAY_SIZE(tc_volatile_ranges),
1480 };
1481 
1482 static bool tc_writeable_reg(struct device *dev, unsigned int reg)
1483 {
1484 	return (reg != TC_IDREG) &&
1485 	       (reg != DP0_LTSTAT) &&
1486 	       (reg != DP0_SNKLTCHGREQ);
1487 }
1488 
1489 static const struct regmap_config tc_regmap_config = {
1490 	.name = "tc358767",
1491 	.reg_bits = 16,
1492 	.val_bits = 32,
1493 	.reg_stride = 4,
1494 	.max_register = PLL_DBG,
1495 	.cache_type = REGCACHE_RBTREE,
1496 	.readable_reg = tc_readable_reg,
1497 	.volatile_table = &tc_volatile_table,
1498 	.writeable_reg = tc_writeable_reg,
1499 	.reg_format_endian = REGMAP_ENDIAN_BIG,
1500 	.val_format_endian = REGMAP_ENDIAN_LITTLE,
1501 };
1502 
1503 static irqreturn_t tc_irq_handler(int irq, void *arg)
1504 {
1505 	struct tc_data *tc = arg;
1506 	u32 val;
1507 	int r;
1508 
1509 	r = regmap_read(tc->regmap, INTSTS_G, &val);
1510 	if (r)
1511 		return IRQ_NONE;
1512 
1513 	if (!val)
1514 		return IRQ_NONE;
1515 
1516 	if (val & INT_SYSERR) {
1517 		u32 stat = 0;
1518 
1519 		regmap_read(tc->regmap, SYSSTAT, &stat);
1520 
1521 		dev_err(tc->dev, "syserr %x\n", stat);
1522 	}
1523 
1524 	if (tc->hpd_pin >= 0 && tc->bridge.dev) {
1525 		/*
1526 		 * H is triggered when the GPIO goes high.
1527 		 *
1528 		 * LC is triggered when the GPIO goes low and stays low for
1529 		 * the duration of LCNT
1530 		 */
1531 		bool h = val & INT_GPIO_H(tc->hpd_pin);
1532 		bool lc = val & INT_GPIO_LC(tc->hpd_pin);
1533 
1534 		dev_dbg(tc->dev, "GPIO%d: %s %s\n", tc->hpd_pin,
1535 			h ? "H" : "", lc ? "LC" : "");
1536 
1537 		if (h || lc)
1538 			drm_kms_helper_hotplug_event(tc->bridge.dev);
1539 	}
1540 
1541 	regmap_write(tc->regmap, INTSTS_G, val);
1542 
1543 	return IRQ_HANDLED;
1544 }
1545 
1546 static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id)
1547 {
1548 	struct device *dev = &client->dev;
1549 	struct tc_data *tc;
1550 	int ret;
1551 
1552 	tc = devm_kzalloc(dev, sizeof(*tc), GFP_KERNEL);
1553 	if (!tc)
1554 		return -ENOMEM;
1555 
1556 	tc->dev = dev;
1557 
1558 	/* port@2 is the output port */
1559 	ret = drm_of_find_panel_or_bridge(dev->of_node, 2, 0, &tc->panel, NULL);
1560 	if (ret && ret != -ENODEV)
1561 		return ret;
1562 
1563 	/* Shut down GPIO is optional */
1564 	tc->sd_gpio = devm_gpiod_get_optional(dev, "shutdown", GPIOD_OUT_HIGH);
1565 	if (IS_ERR(tc->sd_gpio))
1566 		return PTR_ERR(tc->sd_gpio);
1567 
1568 	if (tc->sd_gpio) {
1569 		gpiod_set_value_cansleep(tc->sd_gpio, 0);
1570 		usleep_range(5000, 10000);
1571 	}
1572 
1573 	/* Reset GPIO is optional */
1574 	tc->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
1575 	if (IS_ERR(tc->reset_gpio))
1576 		return PTR_ERR(tc->reset_gpio);
1577 
1578 	if (tc->reset_gpio) {
1579 		gpiod_set_value_cansleep(tc->reset_gpio, 1);
1580 		usleep_range(5000, 10000);
1581 	}
1582 
1583 	tc->refclk = devm_clk_get(dev, "ref");
1584 	if (IS_ERR(tc->refclk)) {
1585 		ret = PTR_ERR(tc->refclk);
1586 		dev_err(dev, "Failed to get refclk: %d\n", ret);
1587 		return ret;
1588 	}
1589 
1590 	tc->regmap = devm_regmap_init_i2c(client, &tc_regmap_config);
1591 	if (IS_ERR(tc->regmap)) {
1592 		ret = PTR_ERR(tc->regmap);
1593 		dev_err(dev, "Failed to initialize regmap: %d\n", ret);
1594 		return ret;
1595 	}
1596 
1597 	ret = of_property_read_u32(dev->of_node, "toshiba,hpd-pin",
1598 				   &tc->hpd_pin);
1599 	if (ret) {
1600 		tc->hpd_pin = -ENODEV;
1601 	} else {
1602 		if (tc->hpd_pin < 0 || tc->hpd_pin > 1) {
1603 			dev_err(dev, "failed to parse HPD number\n");
1604 			return ret;
1605 		}
1606 	}
1607 
1608 	if (client->irq > 0) {
1609 		/* enable SysErr */
1610 		regmap_write(tc->regmap, INTCTL_G, INT_SYSERR);
1611 
1612 		ret = devm_request_threaded_irq(dev, client->irq,
1613 						NULL, tc_irq_handler,
1614 						IRQF_ONESHOT,
1615 						"tc358767-irq", tc);
1616 		if (ret) {
1617 			dev_err(dev, "failed to register dp interrupt\n");
1618 			return ret;
1619 		}
1620 
1621 		tc->have_irq = true;
1622 	}
1623 
1624 	ret = regmap_read(tc->regmap, TC_IDREG, &tc->rev);
1625 	if (ret) {
1626 		dev_err(tc->dev, "can not read device ID: %d\n", ret);
1627 		return ret;
1628 	}
1629 
1630 	if ((tc->rev != 0x6601) && (tc->rev != 0x6603)) {
1631 		dev_err(tc->dev, "invalid device ID: 0x%08x\n", tc->rev);
1632 		return -EINVAL;
1633 	}
1634 
1635 	tc->assr = (tc->rev == 0x6601); /* Enable ASSR for eDP panels */
1636 
1637 	if (!tc->reset_gpio) {
1638 		/*
1639 		 * If the reset pin isn't present, do a software reset. It isn't
1640 		 * as thorough as the hardware reset, as we can't reset the I2C
1641 		 * communication block for obvious reasons, but it's getting the
1642 		 * chip into a defined state.
1643 		 */
1644 		regmap_update_bits(tc->regmap, SYSRSTENB,
1645 				ENBLCD0 | ENBBM | ENBDSIRX | ENBREG | ENBHDCP,
1646 				0);
1647 		regmap_update_bits(tc->regmap, SYSRSTENB,
1648 				ENBLCD0 | ENBBM | ENBDSIRX | ENBREG | ENBHDCP,
1649 				ENBLCD0 | ENBBM | ENBDSIRX | ENBREG | ENBHDCP);
1650 		usleep_range(5000, 10000);
1651 	}
1652 
1653 	if (tc->hpd_pin >= 0) {
1654 		u32 lcnt_reg = tc->hpd_pin == 0 ? INT_GP0_LCNT : INT_GP1_LCNT;
1655 		u32 h_lc = INT_GPIO_H(tc->hpd_pin) | INT_GPIO_LC(tc->hpd_pin);
1656 
1657 		/* Set LCNT to 2ms */
1658 		regmap_write(tc->regmap, lcnt_reg,
1659 			     clk_get_rate(tc->refclk) * 2 / 1000);
1660 		/* We need the "alternate" mode for HPD */
1661 		regmap_write(tc->regmap, GPIOM, BIT(tc->hpd_pin));
1662 
1663 		if (tc->have_irq) {
1664 			/* enable H & LC */
1665 			regmap_update_bits(tc->regmap, INTCTL_G, h_lc, h_lc);
1666 		}
1667 	}
1668 
1669 	ret = tc_aux_link_setup(tc);
1670 	if (ret)
1671 		return ret;
1672 
1673 	/* Register DP AUX channel */
1674 	tc->aux.name = "TC358767 AUX i2c adapter";
1675 	tc->aux.dev = tc->dev;
1676 	tc->aux.transfer = tc_aux_transfer;
1677 	ret = drm_dp_aux_register(&tc->aux);
1678 	if (ret)
1679 		return ret;
1680 
1681 	tc->bridge.funcs = &tc_bridge_funcs;
1682 	tc->bridge.of_node = dev->of_node;
1683 	drm_bridge_add(&tc->bridge);
1684 
1685 	i2c_set_clientdata(client, tc);
1686 
1687 	return 0;
1688 }
1689 
1690 static int tc_remove(struct i2c_client *client)
1691 {
1692 	struct tc_data *tc = i2c_get_clientdata(client);
1693 
1694 	drm_bridge_remove(&tc->bridge);
1695 	drm_dp_aux_unregister(&tc->aux);
1696 
1697 	return 0;
1698 }
1699 
1700 static const struct i2c_device_id tc358767_i2c_ids[] = {
1701 	{ "tc358767", 0 },
1702 	{ }
1703 };
1704 MODULE_DEVICE_TABLE(i2c, tc358767_i2c_ids);
1705 
1706 static const struct of_device_id tc358767_of_ids[] = {
1707 	{ .compatible = "toshiba,tc358767", },
1708 	{ }
1709 };
1710 MODULE_DEVICE_TABLE(of, tc358767_of_ids);
1711 
1712 static struct i2c_driver tc358767_driver = {
1713 	.driver = {
1714 		.name = "tc358767",
1715 		.of_match_table = tc358767_of_ids,
1716 	},
1717 	.id_table = tc358767_i2c_ids,
1718 	.probe = tc_probe,
1719 	.remove	= tc_remove,
1720 };
1721 module_i2c_driver(tc358767_driver);
1722 
1723 MODULE_AUTHOR("Andrey Gusakov <andrey.gusakov@cogentembedded.com>");
1724 MODULE_DESCRIPTION("tc358767 eDP encoder driver");
1725 MODULE_LICENSE("GPL");
1726