xref: /linux/drivers/gpu/drm/bridge/tc358768.c (revision 570f7e331f5febb30f1384817463c7e42b65ca7d)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Copyright (C) 2020 Texas Instruments Incorporated - https://www.ti.com
4  *  Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/device.h>
9 #include <linux/gpio/consumer.h>
10 #include <linux/i2c.h>
11 #include <linux/kernel.h>
12 #include <linux/math64.h>
13 #include <linux/media-bus-format.h>
14 #include <linux/minmax.h>
15 #include <linux/module.h>
16 #include <linux/regmap.h>
17 #include <linux/regulator/consumer.h>
18 #include <linux/slab.h>
19 #include <linux/units.h>
20 
21 #include <drm/drm_atomic_helper.h>
22 #include <drm/drm_drv.h>
23 #include <drm/drm_mipi_dsi.h>
24 #include <drm/drm_of.h>
25 #include <drm/drm_panel.h>
26 #include <video/mipi_display.h>
27 #include <video/videomode.h>
28 
29 /* Global (16-bit addressable) */
30 #define TC358768_CHIPID			0x0000
31 #define TC358768_SYSCTL			0x0002
32 #define TC358768_CONFCTL		0x0004
33 #define TC358768_VSDLY			0x0006
34 #define TC358768_DATAFMT		0x0008
35 #define TC358768_GPIOEN			0x000E
36 #define TC358768_GPIODIR		0x0010
37 #define TC358768_GPIOIN			0x0012
38 #define TC358768_GPIOOUT		0x0014
39 #define TC358768_PLLCTL0		0x0016
40 #define TC358768_PLLCTL1		0x0018
41 #define TC358768_CMDBYTE		0x0022
42 #define TC358768_PP_MISC		0x0032
43 #define TC358768_DSITX_DT		0x0050
44 #define TC358768_FIFOSTATUS		0x00F8
45 
46 /* Debug (16-bit addressable) */
47 #define TC358768_VBUFCTRL		0x00E0
48 #define TC358768_VBUFCTRL_VBUF_EN	BIT(15)
49 #define TC358768_VBUFCTRL_TX_EN		BIT(14)
50 #define TC358768_VBUFCTRL_MASK		BIT(13)
51 #define TC358768_DBG_WIDTH		0x00E2
52 #define TC358768_DBG_VBLANK		0x00E4
53 #define TC358768_DBG_DATA		0x00E8
54 
55 /* TX PHY (32-bit addressable) */
56 #define TC358768_CLW_DPHYCONTTX		0x0100
57 #define TC358768_D0W_DPHYCONTTX		0x0104
58 #define TC358768_D1W_DPHYCONTTX		0x0108
59 #define TC358768_D2W_DPHYCONTTX		0x010C
60 #define TC358768_D3W_DPHYCONTTX		0x0110
61 #define TC358768_CLW_CNTRL		0x0140
62 #define TC358768_D0W_CNTRL		0x0144
63 #define TC358768_D1W_CNTRL		0x0148
64 #define TC358768_D2W_CNTRL		0x014C
65 #define TC358768_D3W_CNTRL		0x0150
66 
67 /* TX PPI (32-bit addressable) */
68 #define TC358768_STARTCNTRL		0x0204
69 #define TC358768_DSITXSTATUS		0x0208
70 #define TC358768_LINEINITCNT		0x0210
71 #define TC358768_LPTXTIMECNT		0x0214
72 #define TC358768_TCLK_HEADERCNT		0x0218
73 #define TC358768_TCLK_TRAILCNT		0x021C
74 #define TC358768_THS_HEADERCNT		0x0220
75 #define TC358768_TWAKEUP		0x0224
76 #define TC358768_TCLK_POSTCNT		0x0228
77 #define TC358768_THS_TRAILCNT		0x022C
78 #define TC358768_HSTXVREGCNT		0x0230
79 #define TC358768_HSTXVREGEN		0x0234
80 #define TC358768_TXOPTIONCNTRL		0x0238
81 #define TC358768_BTACNTRL1		0x023C
82 
83 /* TX CTRL (32-bit addressable) */
84 #define TC358768_DSI_CONTROL		0x040C
85 #define TC358768_DSI_STATUS		0x0410
86 #define TC358768_DSI_INT		0x0414
87 #define TC358768_DSI_INT_ENA		0x0418
88 #define TC358768_DSICMD_RDFIFO		0x0430
89 #define TC358768_DSI_ACKERR		0x0434
90 #define TC358768_DSI_ACKERR_INTENA	0x0438
91 #define TC358768_DSI_ACKERR_HALT	0x043c
92 #define TC358768_DSI_RXERR		0x0440
93 #define TC358768_DSI_RXERR_INTENA	0x0444
94 #define TC358768_DSI_RXERR_HALT		0x0448
95 #define TC358768_DSI_ERR		0x044C
96 #define TC358768_DSI_ERR_INTENA		0x0450
97 #define TC358768_DSI_ERR_HALT		0x0454
98 #define TC358768_DSI_CONFW		0x0500
99 #define TC358768_DSI_LPCMD		0x0500
100 #define TC358768_DSI_RESET		0x0504
101 #define TC358768_DSI_INT_CLR		0x050C
102 #define TC358768_DSI_START		0x0518
103 
104 /* DSITX CTRL (16-bit addressable) */
105 #define TC358768_DSICMD_TX		0x0600
106 #define TC358768_DSICMD_TYPE		0x0602
107 #define TC358768_DSICMD_WC		0x0604
108 #define TC358768_DSICMD_WD0		0x0610
109 #define TC358768_DSICMD_WD1		0x0612
110 #define TC358768_DSICMD_WD2		0x0614
111 #define TC358768_DSICMD_WD3		0x0616
112 #define TC358768_DSI_EVENT		0x0620
113 #define TC358768_DSI_VSW		0x0622
114 #define TC358768_DSI_VBPR		0x0624
115 #define TC358768_DSI_VACT		0x0626
116 #define TC358768_DSI_HSW		0x0628
117 #define TC358768_DSI_HBPR		0x062A
118 #define TC358768_DSI_HACT		0x062C
119 
120 /* TC358768_DSI_CONTROL (0x040C) register */
121 #define TC358768_DSI_CONTROL_DSI_MODE	BIT(15)
122 #define TC358768_DSI_CONTROL_TXMD	BIT(7)
123 #define TC358768_DSI_CONTROL_HSCKMD	BIT(5)
124 #define TC358768_DSI_CONTROL_EOTDIS	BIT(0)
125 
126 /* TC358768_DSI_CONFW (0x0500) register */
127 #define TC358768_DSI_CONFW_MODE_SET	(5 << 29)
128 #define TC358768_DSI_CONFW_MODE_CLR	(6 << 29)
129 #define TC358768_DSI_CONFW_ADDR(x)	((x) << 24)
130 
131 /* TC358768_DSICMD_TX (0x0600) register */
132 #define TC358768_DSI_CMDTX_DC_START	BIT(0)
133 
134 static const char * const tc358768_supplies[] = {
135 	"vddc", "vddmipi", "vddio"
136 };
137 
138 struct tc358768_dsi_output {
139 	struct mipi_dsi_device *dev;
140 	struct drm_panel *panel;
141 	struct drm_bridge *bridge;
142 };
143 
144 struct tc358768_priv {
145 	struct device *dev;
146 	struct regmap *regmap;
147 	struct gpio_desc *reset_gpio;
148 	struct regulator_bulk_data supplies[ARRAY_SIZE(tc358768_supplies)];
149 	struct clk *refclk;
150 	int enabled;
151 	int error;
152 
153 	struct mipi_dsi_host dsi_host;
154 	struct drm_bridge bridge;
155 	struct tc358768_dsi_output output;
156 
157 	u32 pd_lines; /* number of Parallel Port Input Data Lines */
158 	u32 dsi_lanes; /* number of DSI Lanes */
159 	u32 dsi_bpp; /* number of Bits Per Pixel over DSI */
160 
161 	/* Parameters for PLL programming */
162 	u32 fbd;	/* PLL feedback divider */
163 	u32 prd;	/* PLL input divider */
164 	u32 frs;	/* PLL Freqency range for HSCK (post divider) */
165 
166 	u32 dsiclk;	/* pll_clk / 2 */
167 	u32 pclk;	/* incoming pclk rate */
168 };
169 
170 static inline struct tc358768_priv *dsi_host_to_tc358768(struct mipi_dsi_host
171 							 *host)
172 {
173 	return container_of(host, struct tc358768_priv, dsi_host);
174 }
175 
176 static inline struct tc358768_priv *bridge_to_tc358768(struct drm_bridge
177 						       *bridge)
178 {
179 	return container_of(bridge, struct tc358768_priv, bridge);
180 }
181 
182 static int tc358768_clear_error(struct tc358768_priv *priv)
183 {
184 	int ret = priv->error;
185 
186 	priv->error = 0;
187 	return ret;
188 }
189 
190 static void tc358768_write(struct tc358768_priv *priv, u32 reg, u32 val)
191 {
192 	/* work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */
193 	int tmpval = val;
194 	size_t count = 2;
195 
196 	if (priv->error)
197 		return;
198 
199 	/* 16-bit register? */
200 	if (reg < 0x100 || reg >= 0x600)
201 		count = 1;
202 
203 	priv->error = regmap_bulk_write(priv->regmap, reg, &tmpval, count);
204 }
205 
206 static void tc358768_read(struct tc358768_priv *priv, u32 reg, u32 *val)
207 {
208 	size_t count = 2;
209 
210 	if (priv->error)
211 		return;
212 
213 	/* 16-bit register? */
214 	if (reg < 0x100 || reg >= 0x600) {
215 		*val = 0;
216 		count = 1;
217 	}
218 
219 	priv->error = regmap_bulk_read(priv->regmap, reg, val, count);
220 }
221 
222 static void tc358768_update_bits(struct tc358768_priv *priv, u32 reg, u32 mask,
223 				 u32 val)
224 {
225 	u32 tmp, orig;
226 
227 	tc358768_read(priv, reg, &orig);
228 
229 	if (priv->error)
230 		return;
231 
232 	tmp = orig & ~mask;
233 	tmp |= val & mask;
234 	if (tmp != orig)
235 		tc358768_write(priv, reg, tmp);
236 }
237 
238 static void tc358768_confw_update_bits(struct tc358768_priv *priv, u16 reg,
239 				       u16 mask, u16 val)
240 {
241 	u8 confw_addr;
242 	u32 confw_val;
243 
244 	switch (reg) {
245 	case TC358768_DSI_CONTROL:
246 		confw_addr = 0x3;
247 		break;
248 	default:
249 		priv->error = -EINVAL;
250 		return;
251 	}
252 
253 	if (mask != val) {
254 		confw_val = TC358768_DSI_CONFW_MODE_CLR |
255 			TC358768_DSI_CONFW_ADDR(confw_addr) |
256 			mask;
257 		tc358768_write(priv, TC358768_DSI_CONFW, confw_val);
258 	}
259 
260 	if (val & mask) {
261 		confw_val = TC358768_DSI_CONFW_MODE_SET |
262 			TC358768_DSI_CONFW_ADDR(confw_addr) |
263 			(val & mask);
264 		tc358768_write(priv, TC358768_DSI_CONFW, confw_val);
265 	}
266 }
267 
268 static void tc358768_dsicmd_tx(struct tc358768_priv *priv)
269 {
270 	u32 val;
271 
272 	/* start transfer */
273 	tc358768_write(priv, TC358768_DSICMD_TX, TC358768_DSI_CMDTX_DC_START);
274 	if (priv->error)
275 		return;
276 
277 	/* wait transfer completion */
278 	priv->error = regmap_read_poll_timeout(priv->regmap, TC358768_DSICMD_TX, val,
279 					       (val & TC358768_DSI_CMDTX_DC_START) == 0,
280 					       100, 100000);
281 }
282 
283 static int tc358768_sw_reset(struct tc358768_priv *priv)
284 {
285 	/* Assert Reset */
286 	tc358768_write(priv, TC358768_SYSCTL, 1);
287 	/* Release Reset, Exit Sleep */
288 	tc358768_write(priv, TC358768_SYSCTL, 0);
289 
290 	return tc358768_clear_error(priv);
291 }
292 
293 static void tc358768_hw_enable(struct tc358768_priv *priv)
294 {
295 	int ret;
296 
297 	if (priv->enabled)
298 		return;
299 
300 	ret = clk_prepare_enable(priv->refclk);
301 	if (ret < 0)
302 		dev_err(priv->dev, "error enabling refclk (%d)\n", ret);
303 
304 	ret = regulator_bulk_enable(ARRAY_SIZE(priv->supplies), priv->supplies);
305 	if (ret < 0)
306 		dev_err(priv->dev, "error enabling regulators (%d)\n", ret);
307 
308 	if (priv->reset_gpio)
309 		usleep_range(200, 300);
310 
311 	/*
312 	 * The RESX is active low (GPIO_ACTIVE_LOW).
313 	 * DEASSERT (value = 0) the reset_gpio to enable the chip
314 	 */
315 	gpiod_set_value_cansleep(priv->reset_gpio, 0);
316 
317 	/* wait for encoder clocks to stabilize */
318 	usleep_range(1000, 2000);
319 
320 	priv->enabled = true;
321 }
322 
323 static void tc358768_hw_disable(struct tc358768_priv *priv)
324 {
325 	int ret;
326 
327 	if (!priv->enabled)
328 		return;
329 
330 	/*
331 	 * The RESX is active low (GPIO_ACTIVE_LOW).
332 	 * ASSERT (value = 1) the reset_gpio to disable the chip
333 	 */
334 	gpiod_set_value_cansleep(priv->reset_gpio, 1);
335 
336 	ret = regulator_bulk_disable(ARRAY_SIZE(priv->supplies),
337 				     priv->supplies);
338 	if (ret < 0)
339 		dev_err(priv->dev, "error disabling regulators (%d)\n", ret);
340 
341 	clk_disable_unprepare(priv->refclk);
342 
343 	priv->enabled = false;
344 }
345 
346 static u32 tc358768_pll_to_pclk(struct tc358768_priv *priv, u32 pll_clk)
347 {
348 	return (u32)div_u64((u64)pll_clk * priv->dsi_lanes, priv->dsi_bpp);
349 }
350 
351 static u32 tc358768_pclk_to_pll(struct tc358768_priv *priv, u32 pclk)
352 {
353 	return (u32)div_u64((u64)pclk * priv->dsi_bpp, priv->dsi_lanes);
354 }
355 
356 static int tc358768_calc_pll(struct tc358768_priv *priv,
357 			     const struct drm_display_mode *mode,
358 			     bool verify_only)
359 {
360 	static const u32 frs_limits[] = {
361 		1000000000,
362 		500000000,
363 		250000000,
364 		125000000,
365 		62500000
366 	};
367 	unsigned long refclk;
368 	u32 prd, target_pll, i, max_pll, min_pll;
369 	u32 frs, best_diff, best_pll, best_prd, best_fbd;
370 
371 	target_pll = tc358768_pclk_to_pll(priv, mode->clock * 1000);
372 
373 	/* pll_clk = RefClk * FBD / PRD * (1 / (2^FRS)) */
374 
375 	for (i = 0; i < ARRAY_SIZE(frs_limits); i++)
376 		if (target_pll >= frs_limits[i])
377 			break;
378 
379 	if (i == ARRAY_SIZE(frs_limits) || i == 0)
380 		return -EINVAL;
381 
382 	frs = i - 1;
383 	max_pll = frs_limits[i - 1];
384 	min_pll = frs_limits[i];
385 
386 	refclk = clk_get_rate(priv->refclk);
387 
388 	best_diff = UINT_MAX;
389 	best_pll = 0;
390 	best_prd = 0;
391 	best_fbd = 0;
392 
393 	for (prd = 1; prd <= 16; ++prd) {
394 		u32 divisor = prd * (1 << frs);
395 		u32 fbd;
396 
397 		for (fbd = 1; fbd <= 512; ++fbd) {
398 			u32 pll, diff, pll_in;
399 
400 			pll = (u32)div_u64((u64)refclk * fbd, divisor);
401 
402 			if (pll >= max_pll || pll < min_pll)
403 				continue;
404 
405 			pll_in = (u32)div_u64((u64)refclk, prd);
406 			if (pll_in < 4000000)
407 				continue;
408 
409 			diff = max(pll, target_pll) - min(pll, target_pll);
410 
411 			if (diff < best_diff) {
412 				best_diff = diff;
413 				best_pll = pll;
414 				best_prd = prd;
415 				best_fbd = fbd;
416 
417 				if (best_diff == 0)
418 					goto found;
419 			}
420 		}
421 	}
422 
423 	if (best_diff == UINT_MAX) {
424 		dev_err(priv->dev, "could not find suitable PLL setup\n");
425 		return -EINVAL;
426 	}
427 
428 found:
429 	if (verify_only)
430 		return 0;
431 
432 	priv->fbd = best_fbd;
433 	priv->prd = best_prd;
434 	priv->frs = frs;
435 	priv->dsiclk = best_pll / 2;
436 	priv->pclk = mode->clock * 1000;
437 
438 	return 0;
439 }
440 
441 static int tc358768_dsi_host_attach(struct mipi_dsi_host *host,
442 				    struct mipi_dsi_device *dev)
443 {
444 	struct tc358768_priv *priv = dsi_host_to_tc358768(host);
445 	struct drm_bridge *bridge;
446 	struct drm_panel *panel;
447 	struct device_node *ep;
448 	int ret;
449 
450 	if (dev->lanes > 4) {
451 		dev_err(priv->dev, "unsupported number of data lanes(%u)\n",
452 			dev->lanes);
453 		return -EINVAL;
454 	}
455 
456 	/*
457 	 * tc358768 supports both Video and Pulse mode, but the driver only
458 	 * implements Video (event) mode currently
459 	 */
460 	if (!(dev->mode_flags & MIPI_DSI_MODE_VIDEO)) {
461 		dev_err(priv->dev, "Only MIPI_DSI_MODE_VIDEO is supported\n");
462 		return -ENOTSUPP;
463 	}
464 
465 	/*
466 	 * tc358768 supports RGB888, RGB666, RGB666_PACKED and RGB565, but only
467 	 * RGB888 is verified.
468 	 */
469 	if (dev->format != MIPI_DSI_FMT_RGB888) {
470 		dev_warn(priv->dev, "Only MIPI_DSI_FMT_RGB888 tested!\n");
471 		return -ENOTSUPP;
472 	}
473 
474 	ret = drm_of_find_panel_or_bridge(host->dev->of_node, 1, 0, &panel,
475 					  &bridge);
476 	if (ret)
477 		return ret;
478 
479 	if (panel) {
480 		bridge = drm_panel_bridge_add_typed(panel,
481 						    DRM_MODE_CONNECTOR_DSI);
482 		drm_panel_put(panel);
483 		if (IS_ERR(bridge))
484 			return PTR_ERR(bridge);
485 
486 		bridge->pre_enable_prev_first = true;
487 	}
488 
489 	priv->output.dev = dev;
490 	priv->output.bridge = bridge;
491 	priv->output.panel = panel;
492 
493 	priv->dsi_lanes = dev->lanes;
494 	priv->dsi_bpp = mipi_dsi_pixel_format_to_bpp(dev->format);
495 
496 	/* get input ep (port0/endpoint0) */
497 	ret = -EINVAL;
498 	ep = of_graph_get_endpoint_by_regs(host->dev->of_node, 0, 0);
499 	if (ep) {
500 		ret = of_property_read_u32(ep, "bus-width", &priv->pd_lines);
501 		if (ret)
502 			ret = of_property_read_u32(ep, "data-lines", &priv->pd_lines);
503 
504 		of_node_put(ep);
505 	}
506 
507 	if (ret)
508 		priv->pd_lines = priv->dsi_bpp;
509 
510 	drm_bridge_add(&priv->bridge);
511 
512 	return 0;
513 }
514 
515 static int tc358768_dsi_host_detach(struct mipi_dsi_host *host,
516 				    struct mipi_dsi_device *dev)
517 {
518 	struct tc358768_priv *priv = dsi_host_to_tc358768(host);
519 
520 	drm_bridge_remove(&priv->bridge);
521 	if (priv->output.panel)
522 		drm_panel_bridge_remove(priv->output.bridge);
523 
524 	return 0;
525 }
526 
527 static ssize_t tc358768_dsi_host_transfer(struct mipi_dsi_host *host,
528 					  const struct mipi_dsi_msg *msg)
529 {
530 	struct tc358768_priv *priv = dsi_host_to_tc358768(host);
531 	struct mipi_dsi_packet packet;
532 	int ret;
533 
534 	if (!priv->enabled) {
535 		dev_err(priv->dev, "Bridge is not enabled\n");
536 		return -ENODEV;
537 	}
538 
539 	if (msg->rx_len) {
540 		dev_warn(priv->dev, "MIPI rx is not supported\n");
541 		return -ENOTSUPP;
542 	}
543 
544 	if (msg->tx_len > 1024) {
545 		dev_warn(priv->dev, "Maximum 1024 byte MIPI tx is supported\n");
546 		return -EINVAL;
547 	}
548 
549 	if (msg->tx_len > 8) {
550 		u32 confctl;
551 
552 		tc358768_read(priv, TC358768_CONFCTL, &confctl);
553 
554 		if (confctl & BIT(6)) {
555 			dev_warn(priv->dev,
556 				 "Video is currently active. Unable to transmit long command\n");
557 			return -EBUSY;
558 		}
559 	}
560 
561 	ret = mipi_dsi_create_packet(&packet, msg);
562 	if (ret)
563 		return ret;
564 
565 	if (mipi_dsi_packet_format_is_short(msg->type)) {
566 		tc358768_write(priv, TC358768_DSICMD_TYPE,
567 			       (0x10 << 8) | (packet.header[0] & 0x3f));
568 		tc358768_write(priv, TC358768_DSICMD_WC, 0);
569 		tc358768_write(priv, TC358768_DSICMD_WD0,
570 			       (packet.header[2] << 8) | packet.header[1]);
571 		tc358768_dsicmd_tx(priv);
572 	} else if (packet.payload_length <= 8) {
573 		tc358768_write(priv, TC358768_DSICMD_TYPE,
574 			       (0x40 << 8) | (packet.header[0] & 0x3f));
575 		tc358768_write(priv, TC358768_DSICMD_WC, packet.payload_length);
576 
577 		for (int i = 0; i < packet.payload_length; i += 2) {
578 			u16 val = packet.payload[i];
579 
580 			if (i + 1 < packet.payload_length)
581 				val |= packet.payload[i + 1] << 8;
582 			tc358768_write(priv, TC358768_DSICMD_WD0 + i, val);
583 		}
584 
585 		tc358768_dsicmd_tx(priv);
586 	} else {
587 		unsigned long tx_sleep_us;
588 		size_t len;
589 
590 		/* For packets over 8 bytes we need to use the video buffer */
591 		tc358768_write(priv, TC358768_DATAFMT, BIT(0));	/* txdt_en */
592 		tc358768_write(priv, TC358768_DSITX_DT, packet.header[0] & 0x3f);
593 		tc358768_write(priv, TC358768_CMDBYTE, packet.payload_length);
594 		tc358768_write(priv, TC358768_VBUFCTRL, TC358768_VBUFCTRL_VBUF_EN);
595 
596 		/*
597 		 * Write the payload in 2-byte chunks, and pad with zeroes to
598 		 * align to 4 bytes.
599 		 */
600 		len = ALIGN(packet.payload_length, 4);
601 
602 		for (int i = 0; i < len; i += 2) {
603 			u16 val = 0;
604 
605 			if (i < packet.payload_length)
606 				val |= packet.payload[i];
607 			if (i + 1 < packet.payload_length)
608 				val |= packet.payload[i + 1] << 8;
609 
610 			tc358768_write(priv, TC358768_DBG_DATA, val);
611 		}
612 
613 		/* Start transmission */
614 		tc358768_write(priv, TC358768_VBUFCTRL,
615 			       TC358768_VBUFCTRL_VBUF_EN |
616 			       TC358768_VBUFCTRL_TX_EN |
617 			       TC358768_VBUFCTRL_MASK);
618 
619 		/*
620 		 * The TC358768 spec says to wait until the transmission has
621 		 * been finished, estimating the sleep time based on the payload
622 		 * and clock rates. We use a simple safe estimate of 2us per
623 		 * byte (LP mode transmission).
624 		 */
625 		tx_sleep_us = packet.payload_length * 2;
626 		usleep_range(tx_sleep_us, tx_sleep_us * 2);
627 
628 		tc358768_write(priv, TC358768_VBUFCTRL, TC358768_VBUFCTRL_MASK);
629 		tc358768_write(priv, TC358768_VBUFCTRL, 0); /* Stop transmission */
630 	}
631 
632 	ret = tc358768_clear_error(priv);
633 	if (ret)
634 		dev_warn(priv->dev, "Software disable failed: %d\n", ret);
635 	else
636 		ret = packet.size;
637 
638 	return ret;
639 }
640 
641 static const struct mipi_dsi_host_ops tc358768_dsi_host_ops = {
642 	.attach = tc358768_dsi_host_attach,
643 	.detach = tc358768_dsi_host_detach,
644 	.transfer = tc358768_dsi_host_transfer,
645 };
646 
647 static int tc358768_bridge_attach(struct drm_bridge *bridge,
648 				  struct drm_encoder *encoder,
649 				  enum drm_bridge_attach_flags flags)
650 {
651 	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
652 
653 	if (!drm_core_check_feature(bridge->dev, DRIVER_ATOMIC)) {
654 		dev_err(priv->dev, "needs atomic updates support\n");
655 		return -ENOTSUPP;
656 	}
657 
658 	return drm_bridge_attach(encoder, priv->output.bridge, bridge,
659 				 flags);
660 }
661 
662 static enum drm_mode_status
663 tc358768_bridge_mode_valid(struct drm_bridge *bridge,
664 			   const struct drm_display_info *info,
665 			   const struct drm_display_mode *mode)
666 {
667 	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
668 
669 	if (tc358768_calc_pll(priv, mode, true))
670 		return MODE_CLOCK_RANGE;
671 
672 	return MODE_OK;
673 }
674 
675 static void tc358768_bridge_atomic_disable(struct drm_bridge *bridge,
676 					   struct drm_atomic_commit *state)
677 {
678 	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
679 	int ret;
680 
681 	/* set FrmStop */
682 	tc358768_update_bits(priv, TC358768_PP_MISC, BIT(15), BIT(15));
683 
684 	/* wait at least for one frame */
685 	msleep(50);
686 
687 	/* clear PP_en */
688 	tc358768_update_bits(priv, TC358768_CONFCTL, BIT(6), 0);
689 
690 	/* set RstPtr */
691 	tc358768_update_bits(priv, TC358768_PP_MISC, BIT(14), BIT(14));
692 
693 	ret = tc358768_clear_error(priv);
694 	if (ret)
695 		dev_warn(priv->dev, "Software disable failed: %d\n", ret);
696 }
697 
698 static void tc358768_bridge_atomic_post_disable(struct drm_bridge *bridge,
699 						struct drm_atomic_commit *state)
700 {
701 	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
702 
703 	tc358768_hw_disable(priv);
704 }
705 
706 static int tc358768_setup_pll(struct tc358768_priv *priv,
707 			      const struct drm_display_mode *mode)
708 {
709 	u32 fbd, prd, frs;
710 	int ret;
711 
712 	ret = tc358768_calc_pll(priv, mode, false);
713 	if (ret) {
714 		dev_err(priv->dev, "PLL calculation failed: %d\n", ret);
715 		return ret;
716 	}
717 
718 	fbd = priv->fbd;
719 	prd = priv->prd;
720 	frs = priv->frs;
721 
722 	dev_dbg(priv->dev, "PLL: refclk %lu, fbd %u, prd %u, frs %u\n",
723 		clk_get_rate(priv->refclk), fbd, prd, frs);
724 	dev_dbg(priv->dev, "PLL: pll_clk: %u, DSIClk %u, HSByteClk %u\n",
725 		priv->dsiclk * 2, priv->dsiclk, priv->dsiclk / 4);
726 	dev_dbg(priv->dev, "PLL: pclk %u (panel: %u)\n",
727 		tc358768_pll_to_pclk(priv, priv->dsiclk * 2),
728 		mode->clock * 1000);
729 
730 	/* PRD[15:12] FBD[8:0] */
731 	tc358768_write(priv, TC358768_PLLCTL0, ((prd - 1) << 12) | (fbd - 1));
732 
733 	/* FRS[11:10] LBWS[9:8] CKEN[4] RESETB[1] EN[0] */
734 	tc358768_write(priv, TC358768_PLLCTL1,
735 		       (frs << 10) | (0x2 << 8) | BIT(1) | BIT(0));
736 
737 	/* wait for lock */
738 	usleep_range(1000, 2000);
739 
740 	/* FRS[11:10] LBWS[9:8] CKEN[4] PLL_CKEN[4] RESETB[1] EN[0] */
741 	tc358768_write(priv, TC358768_PLLCTL1,
742 		       (frs << 10) | (0x2 << 8) | BIT(4) | BIT(1) | BIT(0));
743 
744 	return tc358768_clear_error(priv);
745 }
746 
747 static u32 tc358768_ns_to_cnt(u32 ns, u32 period_ps)
748 {
749 	return DIV_ROUND_UP(ns * 1000, period_ps);
750 }
751 
752 static u32 tc358768_ps_to_ns(u32 ps)
753 {
754 	return ps / 1000;
755 }
756 
757 static u32 tc358768_dpi_to_ns(u32 val, u32 pclk)
758 {
759 	return (u32)div_u64((u64)val * NANO, pclk);
760 }
761 
762 /* Convert value in DPI pixel clock units to DSI byte count */
763 static u32 tc358768_dpi_to_dsi_bytes(struct tc358768_priv *priv, u32 val)
764 {
765 	u64 m = (u64)val * priv->dsiclk / 4 * priv->dsi_lanes;
766 	u64 n = priv->pclk;
767 
768 	return (u32)div_u64(m + n - 1, n);
769 }
770 
771 static u32 tc358768_dsi_bytes_to_ns(struct tc358768_priv *priv, u32 val)
772 {
773 	u64 m = (u64)val * NANO;
774 	u64 n = priv->dsiclk / 4 * priv->dsi_lanes;
775 
776 	return (u32)div_u64(m, n);
777 }
778 
779 static void tc358768_bridge_atomic_pre_enable(struct drm_bridge *bridge,
780 					      struct drm_atomic_commit *state)
781 {
782 	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
783 	struct mipi_dsi_device *dsi_dev = priv->output.dev;
784 	u32 val, mask, val2, lptxcnt, hact;
785 	s32 raw_val;
786 	struct drm_crtc_state *crtc_state;
787 	struct drm_connector_state *conn_state;
788 	struct drm_connector *connector;
789 	const struct drm_display_mode *mode;
790 	u32 hsbyteclk_ps, dsiclk_ps, ui_ps;
791 	u32 dsiclk, hsbyteclk;
792 	int ret, i;
793 	struct videomode vm;
794 	struct device *dev = priv->dev;
795 	/* In pixelclock units */
796 	u32 dpi_htot, dpi_data_start;
797 	/* In byte units */
798 	u32 dsi_dpi_htot, dsi_dpi_data_start;
799 	u32 dsi_hsw, dsi_hbp, dsi_hact, dsi_hfp;
800 	const u32 dsi_hss = 4; /* HSS is a short packet (4 bytes) */
801 	/* In hsbyteclk units */
802 	u32 dsi_vsdly;
803 	const u32 internal_dly = 40;
804 
805 	tc358768_hw_enable(priv);
806 
807 	ret = tc358768_sw_reset(priv);
808 	if (ret) {
809 		dev_err(dev, "Software reset failed: %d\n", ret);
810 		tc358768_hw_disable(priv);
811 		return;
812 	}
813 
814 	/* Release RstPtr so that the video buffer can be used for DSI commands */
815 	tc358768_update_bits(priv, TC358768_PP_MISC, BIT(14), 0);
816 
817 	connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
818 	conn_state = drm_atomic_get_new_connector_state(state, connector);
819 	crtc_state = drm_atomic_get_new_crtc_state(state, conn_state->crtc);
820 	mode = &crtc_state->adjusted_mode;
821 	ret = tc358768_setup_pll(priv, mode);
822 	if (ret) {
823 		dev_err(dev, "PLL setup failed: %d\n", ret);
824 		tc358768_hw_disable(priv);
825 		return;
826 	}
827 
828 	drm_display_mode_to_videomode(mode, &vm);
829 
830 	dsiclk = priv->dsiclk;
831 	hsbyteclk = dsiclk / 4;
832 
833 	switch (dsi_dev->format) {
834 	case MIPI_DSI_FMT_RGB888:
835 		hact = vm.hactive * 3;
836 		break;
837 	case MIPI_DSI_FMT_RGB666:
838 		hact = vm.hactive * 3;
839 		break;
840 
841 	case MIPI_DSI_FMT_RGB666_PACKED:
842 		hact = vm.hactive * 18 / 8;
843 		break;
844 
845 	case MIPI_DSI_FMT_RGB565:
846 		hact = vm.hactive * 2;
847 		break;
848 	default:
849 		dev_err(dev, "Invalid data format (%u)\n",
850 			dsi_dev->format);
851 		tc358768_hw_disable(priv);
852 		return;
853 	}
854 
855 	/*
856 	 * There are three important things to make TC358768 work correctly,
857 	 * which are not trivial to manage:
858 	 *
859 	 * 1. Keep the DPI line-time and the DSI line-time as close to each
860 	 *    other as possible.
861 	 * 2. TC358768 goes to LP mode after each line's active area. The DSI
862 	 *    HFP period has to be long enough for entering and exiting LP mode.
863 	 *    But it is not clear how to calculate this.
864 	 * 3. VSDly (video start delay) has to be long enough to ensure that the
865 	 *    DSI TX does not start transmitting until we have started receiving
866 	 *    pixel data from the DPI input. It is not clear how to calculate
867 	 *    this either.
868 	 */
869 
870 	dpi_htot = vm.hactive + vm.hfront_porch + vm.hsync_len + vm.hback_porch;
871 	dpi_data_start = vm.hsync_len + vm.hback_porch;
872 
873 	dev_dbg(dev, "dpi horiz timing (pclk): %u + %u + %u + %u = %u\n",
874 		vm.hsync_len, vm.hback_porch, vm.hactive, vm.hfront_porch,
875 		dpi_htot);
876 
877 	dev_dbg(dev, "dpi horiz timing (ns): %u + %u + %u + %u = %u\n",
878 		tc358768_dpi_to_ns(vm.hsync_len, vm.pixelclock),
879 		tc358768_dpi_to_ns(vm.hback_porch, vm.pixelclock),
880 		tc358768_dpi_to_ns(vm.hactive, vm.pixelclock),
881 		tc358768_dpi_to_ns(vm.hfront_porch, vm.pixelclock),
882 		tc358768_dpi_to_ns(dpi_htot, vm.pixelclock));
883 
884 	dev_dbg(dev, "dpi data start (ns): %u + %u = %u\n",
885 		tc358768_dpi_to_ns(vm.hsync_len, vm.pixelclock),
886 		tc358768_dpi_to_ns(vm.hback_porch, vm.pixelclock),
887 		tc358768_dpi_to_ns(dpi_data_start, vm.pixelclock));
888 
889 	dsi_dpi_htot = tc358768_dpi_to_dsi_bytes(priv, dpi_htot);
890 	dsi_dpi_data_start = tc358768_dpi_to_dsi_bytes(priv, dpi_data_start);
891 
892 	if (dsi_dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) {
893 		dsi_hsw = tc358768_dpi_to_dsi_bytes(priv, vm.hsync_len);
894 		dsi_hbp = tc358768_dpi_to_dsi_bytes(priv, vm.hback_porch);
895 	} else {
896 		/* HBP is included in HSW in event mode */
897 		dsi_hbp = 0;
898 		dsi_hsw = tc358768_dpi_to_dsi_bytes(priv,
899 						    vm.hsync_len +
900 						    vm.hback_porch);
901 
902 		/*
903 		 * The pixel packet includes the actual pixel data, and:
904 		 * DSI packet header = 4 bytes
905 		 * DCS code = 1 byte
906 		 * DSI packet footer = 2 bytes
907 		 */
908 		dsi_hact = hact + 4 + 1 + 2;
909 
910 		dsi_hfp = dsi_dpi_htot - dsi_hact - dsi_hsw - dsi_hss;
911 
912 		/*
913 		 * Here we should check if HFP is long enough for entering LP
914 		 * and exiting LP, but it's not clear how to calculate that.
915 		 * Instead, this is a naive algorithm that just adjusts the HFP
916 		 * and HSW so that HFP is (at least) roughly 2/3 of the total
917 		 * blanking time.
918 		 */
919 		if (dsi_hfp < (dsi_hfp + dsi_hsw + dsi_hss) * 2 / 3) {
920 			u32 old_hfp = dsi_hfp;
921 			u32 old_hsw = dsi_hsw;
922 			u32 tot = dsi_hfp + dsi_hsw + dsi_hss;
923 
924 			dsi_hsw = tot / 3;
925 
926 			/*
927 			 * Seems like sometimes HSW has to be divisible by num-lanes, but
928 			 * not always...
929 			 */
930 			dsi_hsw = roundup(dsi_hsw, priv->dsi_lanes);
931 
932 			dsi_hfp = dsi_dpi_htot - dsi_hact - dsi_hsw - dsi_hss;
933 
934 			dev_dbg(dev,
935 				"hfp too short, adjusting dsi hfp and dsi hsw from %u, %u to %u, %u\n",
936 				old_hfp, old_hsw, dsi_hfp, dsi_hsw);
937 		}
938 
939 		dev_dbg(dev,
940 			"dsi horiz timing (bytes): %u, %u + %u + %u + %u = %u\n",
941 			dsi_hss, dsi_hsw, dsi_hbp, dsi_hact, dsi_hfp,
942 			dsi_hss + dsi_hsw + dsi_hbp + dsi_hact + dsi_hfp);
943 
944 		dev_dbg(dev, "dsi horiz timing (ns): %u + %u + %u + %u + %u = %u\n",
945 			tc358768_dsi_bytes_to_ns(priv, dsi_hss),
946 			tc358768_dsi_bytes_to_ns(priv, dsi_hsw),
947 			tc358768_dsi_bytes_to_ns(priv, dsi_hbp),
948 			tc358768_dsi_bytes_to_ns(priv, dsi_hact),
949 			tc358768_dsi_bytes_to_ns(priv, dsi_hfp),
950 			tc358768_dsi_bytes_to_ns(priv, dsi_hss + dsi_hsw +
951 						 dsi_hbp + dsi_hact + dsi_hfp));
952 	}
953 
954 	/* VSDly calculation */
955 
956 	/* Start with the HW internal delay */
957 	dsi_vsdly = internal_dly;
958 
959 	/* Convert to byte units as the other variables are in byte units */
960 	dsi_vsdly *= priv->dsi_lanes;
961 
962 	/* Do we need more delay, in addition to the internal? */
963 	if (dsi_dpi_data_start > dsi_vsdly + dsi_hss + dsi_hsw + dsi_hbp) {
964 		dsi_vsdly = dsi_dpi_data_start - dsi_hss - dsi_hsw - dsi_hbp;
965 		dsi_vsdly = roundup(dsi_vsdly, priv->dsi_lanes);
966 	}
967 
968 	dev_dbg(dev, "dsi data start (bytes) %u + %u + %u + %u = %u\n",
969 		dsi_vsdly, dsi_hss, dsi_hsw, dsi_hbp,
970 		dsi_vsdly + dsi_hss + dsi_hsw + dsi_hbp);
971 
972 	dev_dbg(dev, "dsi data start (ns) %u + %u + %u + %u = %u\n",
973 		tc358768_dsi_bytes_to_ns(priv, dsi_vsdly),
974 		tc358768_dsi_bytes_to_ns(priv, dsi_hss),
975 		tc358768_dsi_bytes_to_ns(priv, dsi_hsw),
976 		tc358768_dsi_bytes_to_ns(priv, dsi_hbp),
977 		tc358768_dsi_bytes_to_ns(priv, dsi_vsdly + dsi_hss + dsi_hsw + dsi_hbp));
978 
979 	/* Convert back to hsbyteclk */
980 	dsi_vsdly /= priv->dsi_lanes;
981 
982 	/*
983 	 * The docs say that there is an internal delay of 40 cycles.
984 	 * However, we get underflows if we follow that rule. If we
985 	 * instead ignore the internal delay, things work. So either
986 	 * the docs are wrong or the calculations are wrong.
987 	 *
988 	 * As a temporary fix, add the internal delay here, to counter
989 	 * the subtraction when writing the register.
990 	 */
991 	dsi_vsdly += internal_dly;
992 
993 	/* Clamp to the register max */
994 	if (dsi_vsdly - internal_dly > 0x3ff) {
995 		dev_warn(dev, "VSDly too high, underflows likely\n");
996 		dsi_vsdly = 0x3ff + internal_dly;
997 	}
998 
999 	/* VSDly[9:0] */
1000 	tc358768_write(priv, TC358768_VSDLY, dsi_vsdly - internal_dly);
1001 
1002 	/* Enable D-PHY (HiZ->LP11) */
1003 	tc358768_write(priv, TC358768_CLW_CNTRL, 0x0000);
1004 	/* Enable lanes */
1005 	for (i = 0; i < dsi_dev->lanes; i++)
1006 		tc358768_write(priv, TC358768_D0W_CNTRL + i * 4, 0x0000);
1007 
1008 	/* DSI Timings */
1009 	hsbyteclk_ps = (u32)div_u64(PICO, hsbyteclk);
1010 	dsiclk_ps = (u32)div_u64(PICO, dsiclk);
1011 	ui_ps = dsiclk_ps / 2;
1012 	dev_dbg(dev, "dsiclk: %u ps, ui %u ps, hsbyteclk %u ps\n", dsiclk_ps,
1013 		ui_ps, hsbyteclk_ps);
1014 
1015 	/* LP11 > 100us for D-PHY Rx Init */
1016 	val = tc358768_ns_to_cnt(100 * 1000, hsbyteclk_ps) - 1;
1017 	dev_dbg(dev, "LINEINITCNT: %u\n", val);
1018 	tc358768_write(priv, TC358768_LINEINITCNT, val);
1019 
1020 	/* LPTimeCnt > 50ns */
1021 	val = tc358768_ns_to_cnt(50, hsbyteclk_ps) - 1;
1022 	lptxcnt = val;
1023 	dev_dbg(dev, "LPTXTIMECNT: %u\n", val);
1024 	tc358768_write(priv, TC358768_LPTXTIMECNT, val);
1025 
1026 	/* 38ns < TCLK_PREPARE < 95ns */
1027 	val = tc358768_ns_to_cnt(65, hsbyteclk_ps) - 1;
1028 	dev_dbg(dev, "TCLK_PREPARECNT %u\n", val);
1029 	/* TCLK_PREPARE + TCLK_ZERO > 300ns */
1030 	val2 = tc358768_ns_to_cnt(300 - tc358768_ps_to_ns(2 * ui_ps),
1031 				  hsbyteclk_ps) - 2;
1032 	dev_dbg(dev, "TCLK_ZEROCNT %u\n", val2);
1033 	val |= val2 << 8;
1034 	tc358768_write(priv, TC358768_TCLK_HEADERCNT, val);
1035 
1036 	/* TCLK_TRAIL > 60ns AND TEOT <= 105 ns + 12*UI */
1037 	raw_val = tc358768_ns_to_cnt(60 + tc358768_ps_to_ns(2 * ui_ps), hsbyteclk_ps) - 5;
1038 	val = clamp(raw_val, 0, 127);
1039 	dev_dbg(dev, "TCLK_TRAILCNT: %u\n", val);
1040 	tc358768_write(priv, TC358768_TCLK_TRAILCNT, val);
1041 
1042 	/* 40ns + 4*UI < THS_PREPARE < 85ns + 6*UI */
1043 	val = 50 + tc358768_ps_to_ns(4 * ui_ps);
1044 	val = tc358768_ns_to_cnt(val, hsbyteclk_ps) - 1;
1045 	dev_dbg(dev, "THS_PREPARECNT %u\n", val);
1046 	/* THS_PREPARE + THS_ZERO > 145ns + 10*UI */
1047 	raw_val = tc358768_ns_to_cnt(145 - tc358768_ps_to_ns(3 * ui_ps), hsbyteclk_ps) - 10;
1048 	val2 = clamp(raw_val, 0, 127);
1049 	dev_dbg(dev, "THS_ZEROCNT %u\n", val2);
1050 	val |= val2 << 8;
1051 	tc358768_write(priv, TC358768_THS_HEADERCNT, val);
1052 
1053 	/* TWAKEUP > 1ms in lptxcnt steps */
1054 	val = tc358768_ns_to_cnt(1020000, hsbyteclk_ps);
1055 	val = val / (lptxcnt + 1) - 1;
1056 	dev_dbg(dev, "TWAKEUP: %u\n", val);
1057 	tc358768_write(priv, TC358768_TWAKEUP, val);
1058 
1059 	/* TCLK_POSTCNT > 60ns + 52*UI */
1060 	val = tc358768_ns_to_cnt(60 + tc358768_ps_to_ns(52 * ui_ps),
1061 				 hsbyteclk_ps) - 3;
1062 	dev_dbg(dev, "TCLK_POSTCNT: %u\n", val);
1063 	tc358768_write(priv, TC358768_TCLK_POSTCNT, val);
1064 
1065 	/* max(60ns + 4*UI, 8*UI) < THS_TRAILCNT < 105ns + 12*UI */
1066 	raw_val = tc358768_ns_to_cnt(60 + tc358768_ps_to_ns(18 * ui_ps),
1067 				     hsbyteclk_ps) - 4;
1068 	val = clamp(raw_val, 0, 15);
1069 	dev_dbg(dev, "THS_TRAILCNT: %u\n", val);
1070 	tc358768_write(priv, TC358768_THS_TRAILCNT, val);
1071 
1072 	val = BIT(0);
1073 	for (i = 0; i < dsi_dev->lanes; i++)
1074 		val |= BIT(i + 1);
1075 	tc358768_write(priv, TC358768_HSTXVREGEN, val);
1076 
1077 	tc358768_write(priv, TC358768_TXOPTIONCNTRL,
1078 		       (dsi_dev->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) ? 0 : BIT(0));
1079 
1080 	/* TXTAGOCNT[26:16] RXTASURECNT[10:0] */
1081 	val = tc358768_ps_to_ns((lptxcnt + 1) * hsbyteclk_ps * 4);
1082 	val = tc358768_ns_to_cnt(val, hsbyteclk_ps) / 4 - 1;
1083 	dev_dbg(dev, "TXTAGOCNT: %u\n", val);
1084 	val2 = tc358768_ns_to_cnt(tc358768_ps_to_ns((lptxcnt + 1) * hsbyteclk_ps),
1085 				  hsbyteclk_ps) - 2;
1086 	dev_dbg(dev, "RXTASURECNT: %u\n", val2);
1087 	val = val << 16 | val2;
1088 	tc358768_write(priv, TC358768_BTACNTRL1, val);
1089 
1090 	/* START[0] */
1091 	tc358768_write(priv, TC358768_STARTCNTRL, 1);
1092 
1093 	if (dsi_dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) {
1094 		/* Set pulse mode */
1095 		tc358768_write(priv, TC358768_DSI_EVENT, 0);
1096 
1097 		/* vact */
1098 		tc358768_write(priv, TC358768_DSI_VACT, vm.vactive);
1099 
1100 		/* vsw */
1101 		tc358768_write(priv, TC358768_DSI_VSW, vm.vsync_len);
1102 
1103 		/* vbp */
1104 		tc358768_write(priv, TC358768_DSI_VBPR, vm.vback_porch);
1105 	} else {
1106 		/* Set event mode */
1107 		tc358768_write(priv, TC358768_DSI_EVENT, 1);
1108 
1109 		/* vact */
1110 		tc358768_write(priv, TC358768_DSI_VACT, vm.vactive);
1111 
1112 		/* vsw (+ vbp) */
1113 		tc358768_write(priv, TC358768_DSI_VSW,
1114 			       vm.vsync_len + vm.vback_porch);
1115 
1116 		/* vbp (not used in event mode) */
1117 		tc358768_write(priv, TC358768_DSI_VBPR, 0);
1118 	}
1119 
1120 	/* hsw (bytes) */
1121 	tc358768_write(priv, TC358768_DSI_HSW, dsi_hsw);
1122 
1123 	/* hbp (bytes) */
1124 	tc358768_write(priv, TC358768_DSI_HBPR, dsi_hbp);
1125 
1126 	/* hact (bytes) */
1127 	tc358768_write(priv, TC358768_DSI_HACT, hact);
1128 
1129 	/* VSYNC polarity */
1130 	tc358768_update_bits(priv, TC358768_CONFCTL, BIT(5),
1131 			     (mode->flags & DRM_MODE_FLAG_PVSYNC) ? BIT(5) : 0);
1132 
1133 	/* HSYNC polarity */
1134 	tc358768_update_bits(priv, TC358768_PP_MISC, BIT(0),
1135 			     (mode->flags & DRM_MODE_FLAG_PHSYNC) ? BIT(0) : 0);
1136 
1137 	/* Start DSI Tx */
1138 	tc358768_write(priv, TC358768_DSI_START, 0x1);
1139 
1140 	/* Configure DSI_Control register */
1141 	val = (dsi_dev->lanes - 1) << 1;
1142 
1143 	if (!(dsi_dev->mode_flags & MIPI_DSI_MODE_LPM))
1144 		val |= TC358768_DSI_CONTROL_TXMD;
1145 
1146 	if (!(dsi_dev->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS))
1147 		val |= TC358768_DSI_CONTROL_HSCKMD;
1148 
1149 	if (dsi_dev->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET)
1150 		val |= TC358768_DSI_CONTROL_EOTDIS;
1151 
1152 	mask = TC358768_DSI_CONTROL_TXMD | TC358768_DSI_CONTROL_HSCKMD |
1153 	       0x3 << 1 | TC358768_DSI_CONTROL_EOTDIS;
1154 
1155 	tc358768_confw_update_bits(priv, TC358768_DSI_CONTROL, mask, val);
1156 
1157 	tc358768_confw_update_bits(priv, TC358768_DSI_CONTROL,
1158 				   TC358768_DSI_CONTROL_DSI_MODE, 0);
1159 
1160 	ret = tc358768_clear_error(priv);
1161 	if (ret)
1162 		dev_err(dev, "Bridge pre_enable failed: %d\n", ret);
1163 }
1164 
1165 static void tc358768_config_video_format(struct tc358768_priv *priv)
1166 {
1167 	struct mipi_dsi_device *dsi_dev = priv->output.dev;
1168 	u32 val, data_type;
1169 
1170 	/* Data Format Control Register */
1171 	val = BIT(2) | BIT(1) | BIT(0); /* rdswap_en | dsitx_en | txdt_en */
1172 	switch (dsi_dev->format) {
1173 	case MIPI_DSI_FMT_RGB888:
1174 		val |= (0x3 << 4);
1175 		data_type = MIPI_DSI_PACKED_PIXEL_STREAM_24;
1176 		break;
1177 	case MIPI_DSI_FMT_RGB666:
1178 		val |= (0x4 << 4);
1179 		data_type = MIPI_DSI_PACKED_PIXEL_STREAM_18;
1180 		break;
1181 	case MIPI_DSI_FMT_RGB666_PACKED:
1182 		val |= (0x4 << 4) | BIT(3);
1183 		data_type = MIPI_DSI_PIXEL_STREAM_3BYTE_18;
1184 		break;
1185 	case MIPI_DSI_FMT_RGB565:
1186 		val |= (0x5 << 4);
1187 		data_type = MIPI_DSI_PACKED_PIXEL_STREAM_16;
1188 		break;
1189 	default:
1190 		dev_err(priv->dev, "Invalid data format (%u)\n", dsi_dev->format);
1191 		return;
1192 	}
1193 
1194 	tc358768_write(priv, TC358768_DATAFMT, val);
1195 	tc358768_write(priv, TC358768_DSITX_DT, data_type);
1196 }
1197 
1198 static void tc358768_bridge_atomic_enable(struct drm_bridge *bridge,
1199 					  struct drm_atomic_commit *state)
1200 {
1201 	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
1202 	int ret;
1203 
1204 	if (!priv->enabled) {
1205 		dev_err(priv->dev, "Bridge is not enabled\n");
1206 		return;
1207 	}
1208 
1209 	/* Configure video format registers */
1210 	tc358768_config_video_format(priv);
1211 
1212 	/* Enable HS mode for video TX */
1213 	tc358768_confw_update_bits(priv, TC358768_DSI_CONTROL,
1214 				   TC358768_DSI_CONTROL_TXMD,
1215 				   TC358768_DSI_CONTROL_TXMD);
1216 
1217 	/* clear FrmStop and RstPtr */
1218 	tc358768_update_bits(priv, TC358768_PP_MISC, 0x3 << 14, 0);
1219 
1220 	/* set PP_en */
1221 	tc358768_update_bits(priv, TC358768_CONFCTL, BIT(6), BIT(6));
1222 
1223 	ret = tc358768_clear_error(priv);
1224 	if (ret)
1225 		dev_err(priv->dev, "Bridge enable failed: %d\n", ret);
1226 }
1227 
1228 #define MAX_INPUT_SEL_FORMATS	1
1229 
1230 static u32 *
1231 tc358768_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
1232 				   struct drm_bridge_state *bridge_state,
1233 				   struct drm_crtc_state *crtc_state,
1234 				   struct drm_connector_state *conn_state,
1235 				   u32 output_fmt,
1236 				   unsigned int *num_input_fmts)
1237 {
1238 	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
1239 	u32 *input_fmts;
1240 
1241 	*num_input_fmts = 0;
1242 
1243 	input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
1244 			     GFP_KERNEL);
1245 	if (!input_fmts)
1246 		return NULL;
1247 
1248 	switch (priv->pd_lines) {
1249 	case 16:
1250 		input_fmts[0] = MEDIA_BUS_FMT_RGB565_1X16;
1251 		break;
1252 	case 18:
1253 		input_fmts[0] = MEDIA_BUS_FMT_RGB666_1X18;
1254 		break;
1255 	default:
1256 	case 24:
1257 		input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
1258 		break;
1259 	}
1260 
1261 	*num_input_fmts = MAX_INPUT_SEL_FORMATS;
1262 
1263 	return input_fmts;
1264 }
1265 
1266 static bool tc358768_mode_fixup(struct drm_bridge *bridge,
1267 				const struct drm_display_mode *mode,
1268 				struct drm_display_mode *adjusted_mode)
1269 {
1270 	/* Default to positive sync */
1271 
1272 	if (!(adjusted_mode->flags &
1273 	      (DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_NHSYNC)))
1274 		adjusted_mode->flags |= DRM_MODE_FLAG_PHSYNC;
1275 
1276 	if (!(adjusted_mode->flags &
1277 	      (DRM_MODE_FLAG_PVSYNC | DRM_MODE_FLAG_NVSYNC)))
1278 		adjusted_mode->flags |= DRM_MODE_FLAG_PVSYNC;
1279 
1280 	return true;
1281 }
1282 
1283 static const struct drm_bridge_funcs tc358768_bridge_funcs = {
1284 	.attach = tc358768_bridge_attach,
1285 	.mode_valid = tc358768_bridge_mode_valid,
1286 	.mode_fixup = tc358768_mode_fixup,
1287 	.atomic_pre_enable = tc358768_bridge_atomic_pre_enable,
1288 	.atomic_enable = tc358768_bridge_atomic_enable,
1289 	.atomic_disable = tc358768_bridge_atomic_disable,
1290 	.atomic_post_disable = tc358768_bridge_atomic_post_disable,
1291 
1292 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
1293 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
1294 	.atomic_create_state = drm_atomic_helper_bridge_create_state,
1295 	.atomic_get_input_bus_fmts = tc358768_atomic_get_input_bus_fmts,
1296 };
1297 
1298 static const struct drm_bridge_timings default_tc358768_timings = {
1299 	.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE
1300 		 | DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE
1301 		 | DRM_BUS_FLAG_DE_HIGH,
1302 };
1303 
1304 static bool tc358768_is_reserved_reg(unsigned int reg)
1305 {
1306 	switch (reg) {
1307 	case 0x114 ... 0x13f:
1308 	case 0x200:
1309 	case 0x20c:
1310 	case 0x400 ... 0x408:
1311 	case 0x41c ... 0x42f:
1312 		return true;
1313 	default:
1314 		return false;
1315 	}
1316 }
1317 
1318 static bool tc358768_writeable_reg(struct device *dev, unsigned int reg)
1319 {
1320 	if (tc358768_is_reserved_reg(reg))
1321 		return false;
1322 
1323 	switch (reg) {
1324 	case TC358768_CHIPID:
1325 	case TC358768_FIFOSTATUS:
1326 	case TC358768_DSITXSTATUS ... (TC358768_DSITXSTATUS + 2):
1327 	case TC358768_DSI_CONTROL ... (TC358768_DSI_INT_ENA + 2):
1328 	case TC358768_DSICMD_RDFIFO ... (TC358768_DSI_ERR_HALT + 2):
1329 		return false;
1330 	default:
1331 		return true;
1332 	}
1333 }
1334 
1335 static bool tc358768_readable_reg(struct device *dev, unsigned int reg)
1336 {
1337 	if (tc358768_is_reserved_reg(reg))
1338 		return false;
1339 
1340 	switch (reg) {
1341 	case TC358768_STARTCNTRL:
1342 	case TC358768_DSI_CONFW ... (TC358768_DSI_CONFW + 2):
1343 	case TC358768_DSI_INT_CLR ... (TC358768_DSI_INT_CLR + 2):
1344 	case TC358768_DSI_START ... (TC358768_DSI_START + 2):
1345 	case TC358768_DBG_DATA:
1346 		return false;
1347 	default:
1348 		return true;
1349 	}
1350 }
1351 
1352 static const struct regmap_config tc358768_regmap_config = {
1353 	.name = "tc358768",
1354 	.reg_bits = 16,
1355 	.val_bits = 16,
1356 	.max_register = TC358768_DSI_HACT,
1357 	.cache_type = REGCACHE_NONE,
1358 	.writeable_reg = tc358768_writeable_reg,
1359 	.readable_reg = tc358768_readable_reg,
1360 	.reg_format_endian = REGMAP_ENDIAN_BIG,
1361 	.val_format_endian = REGMAP_ENDIAN_BIG,
1362 };
1363 
1364 static const struct i2c_device_id tc358768_i2c_ids[] = {
1365 	{ .name = "tc358768" },
1366 	{ .name = "tc358778" },
1367 	{ }
1368 };
1369 MODULE_DEVICE_TABLE(i2c, tc358768_i2c_ids);
1370 
1371 static const struct of_device_id tc358768_of_ids[] = {
1372 	{ .compatible = "toshiba,tc358768", },
1373 	{ .compatible = "toshiba,tc358778", },
1374 	{ }
1375 };
1376 MODULE_DEVICE_TABLE(of, tc358768_of_ids);
1377 
1378 static int tc358768_get_regulators(struct tc358768_priv *priv)
1379 {
1380 	int i, ret;
1381 
1382 	for (i = 0; i < ARRAY_SIZE(priv->supplies); ++i)
1383 		priv->supplies[i].supply = tc358768_supplies[i];
1384 
1385 	ret = devm_regulator_bulk_get(priv->dev, ARRAY_SIZE(priv->supplies),
1386 				      priv->supplies);
1387 	if (ret < 0)
1388 		dev_err(priv->dev, "failed to get regulators: %d\n", ret);
1389 
1390 	return ret;
1391 }
1392 
1393 static int tc358768_i2c_probe(struct i2c_client *client)
1394 {
1395 	struct tc358768_priv *priv;
1396 	struct device *dev = &client->dev;
1397 	struct device_node *np = dev->of_node;
1398 	int ret;
1399 
1400 	if (!np)
1401 		return -ENODEV;
1402 
1403 	priv = devm_drm_bridge_alloc(dev, struct tc358768_priv, bridge,
1404 				     &tc358768_bridge_funcs);
1405 	if (IS_ERR(priv))
1406 		return PTR_ERR(priv);
1407 
1408 	dev_set_drvdata(dev, priv);
1409 	priv->dev = dev;
1410 
1411 	ret = tc358768_get_regulators(priv);
1412 	if (ret)
1413 		return ret;
1414 
1415 	priv->refclk = devm_clk_get(dev, "refclk");
1416 	if (IS_ERR(priv->refclk))
1417 		return PTR_ERR(priv->refclk);
1418 
1419 	/*
1420 	 * RESX is low active, to disable tc358768 initially (keep in reset)
1421 	 * the gpio line must be LOW. This is the ASSERTED state of
1422 	 * GPIO_ACTIVE_LOW (GPIOD_OUT_HIGH == ASSERTED).
1423 	 */
1424 	priv->reset_gpio  = devm_gpiod_get_optional(dev, "reset",
1425 						    GPIOD_OUT_HIGH);
1426 	if (IS_ERR(priv->reset_gpio))
1427 		return PTR_ERR(priv->reset_gpio);
1428 
1429 	priv->regmap = devm_regmap_init_i2c(client, &tc358768_regmap_config);
1430 	if (IS_ERR(priv->regmap)) {
1431 		dev_err(dev, "Failed to init regmap\n");
1432 		return PTR_ERR(priv->regmap);
1433 	}
1434 
1435 	priv->dsi_host.dev = dev;
1436 	priv->dsi_host.ops = &tc358768_dsi_host_ops;
1437 
1438 	priv->bridge.timings = &default_tc358768_timings;
1439 	priv->bridge.of_node = np;
1440 
1441 	i2c_set_clientdata(client, priv);
1442 
1443 	return mipi_dsi_host_register(&priv->dsi_host);
1444 }
1445 
1446 static void tc358768_i2c_remove(struct i2c_client *client)
1447 {
1448 	struct tc358768_priv *priv = i2c_get_clientdata(client);
1449 
1450 	mipi_dsi_host_unregister(&priv->dsi_host);
1451 }
1452 
1453 static struct i2c_driver tc358768_driver = {
1454 	.driver = {
1455 		.name = "tc358768",
1456 		.of_match_table = tc358768_of_ids,
1457 	},
1458 	.id_table = tc358768_i2c_ids,
1459 	.probe = tc358768_i2c_probe,
1460 	.remove	= tc358768_i2c_remove,
1461 };
1462 module_i2c_driver(tc358768_driver);
1463 
1464 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
1465 MODULE_DESCRIPTION("TC358768AXBG/TC358778XBG DSI bridge");
1466 MODULE_LICENSE("GPL v2");
1467