xref: /openbmc/linux/drivers/gpu/drm/bridge/tc358768.c (revision 6bec5b0b70ddb53b03507a9bb1bc206c3e65708e)
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/media-bus-format.h>
13 #include <linux/minmax.h>
14 #include <linux/module.h>
15 #include <linux/regmap.h>
16 #include <linux/regulator/consumer.h>
17 #include <linux/slab.h>
18 
19 #include <drm/drm_atomic_helper.h>
20 #include <drm/drm_drv.h>
21 #include <drm/drm_mipi_dsi.h>
22 #include <drm/drm_of.h>
23 #include <drm/drm_panel.h>
24 #include <video/mipi_display.h>
25 #include <video/videomode.h>
26 
27 /* Global (16-bit addressable) */
28 #define TC358768_CHIPID			0x0000
29 #define TC358768_SYSCTL			0x0002
30 #define TC358768_CONFCTL		0x0004
31 #define TC358768_VSDLY			0x0006
32 #define TC358768_DATAFMT		0x0008
33 #define TC358768_GPIOEN			0x000E
34 #define TC358768_GPIODIR		0x0010
35 #define TC358768_GPIOIN			0x0012
36 #define TC358768_GPIOOUT		0x0014
37 #define TC358768_PLLCTL0		0x0016
38 #define TC358768_PLLCTL1		0x0018
39 #define TC358768_CMDBYTE		0x0022
40 #define TC358768_PP_MISC		0x0032
41 #define TC358768_DSITX_DT		0x0050
42 #define TC358768_FIFOSTATUS		0x00F8
43 
44 /* Debug (16-bit addressable) */
45 #define TC358768_VBUFCTRL		0x00E0
46 #define TC358768_DBG_WIDTH		0x00E2
47 #define TC358768_DBG_VBLANK		0x00E4
48 #define TC358768_DBG_DATA		0x00E8
49 
50 /* TX PHY (32-bit addressable) */
51 #define TC358768_CLW_DPHYCONTTX		0x0100
52 #define TC358768_D0W_DPHYCONTTX		0x0104
53 #define TC358768_D1W_DPHYCONTTX		0x0108
54 #define TC358768_D2W_DPHYCONTTX		0x010C
55 #define TC358768_D3W_DPHYCONTTX		0x0110
56 #define TC358768_CLW_CNTRL		0x0140
57 #define TC358768_D0W_CNTRL		0x0144
58 #define TC358768_D1W_CNTRL		0x0148
59 #define TC358768_D2W_CNTRL		0x014C
60 #define TC358768_D3W_CNTRL		0x0150
61 
62 /* TX PPI (32-bit addressable) */
63 #define TC358768_STARTCNTRL		0x0204
64 #define TC358768_DSITXSTATUS		0x0208
65 #define TC358768_LINEINITCNT		0x0210
66 #define TC358768_LPTXTIMECNT		0x0214
67 #define TC358768_TCLK_HEADERCNT		0x0218
68 #define TC358768_TCLK_TRAILCNT		0x021C
69 #define TC358768_THS_HEADERCNT		0x0220
70 #define TC358768_TWAKEUP		0x0224
71 #define TC358768_TCLK_POSTCNT		0x0228
72 #define TC358768_THS_TRAILCNT		0x022C
73 #define TC358768_HSTXVREGCNT		0x0230
74 #define TC358768_HSTXVREGEN		0x0234
75 #define TC358768_TXOPTIONCNTRL		0x0238
76 #define TC358768_BTACNTRL1		0x023C
77 
78 /* TX CTRL (32-bit addressable) */
79 #define TC358768_DSI_CONTROL		0x040C
80 #define TC358768_DSI_STATUS		0x0410
81 #define TC358768_DSI_INT		0x0414
82 #define TC358768_DSI_INT_ENA		0x0418
83 #define TC358768_DSICMD_RDFIFO		0x0430
84 #define TC358768_DSI_ACKERR		0x0434
85 #define TC358768_DSI_ACKERR_INTENA	0x0438
86 #define TC358768_DSI_ACKERR_HALT	0x043c
87 #define TC358768_DSI_RXERR		0x0440
88 #define TC358768_DSI_RXERR_INTENA	0x0444
89 #define TC358768_DSI_RXERR_HALT		0x0448
90 #define TC358768_DSI_ERR		0x044C
91 #define TC358768_DSI_ERR_INTENA		0x0450
92 #define TC358768_DSI_ERR_HALT		0x0454
93 #define TC358768_DSI_CONFW		0x0500
94 #define TC358768_DSI_LPCMD		0x0500
95 #define TC358768_DSI_RESET		0x0504
96 #define TC358768_DSI_INT_CLR		0x050C
97 #define TC358768_DSI_START		0x0518
98 
99 /* DSITX CTRL (16-bit addressable) */
100 #define TC358768_DSICMD_TX		0x0600
101 #define TC358768_DSICMD_TYPE		0x0602
102 #define TC358768_DSICMD_WC		0x0604
103 #define TC358768_DSICMD_WD0		0x0610
104 #define TC358768_DSICMD_WD1		0x0612
105 #define TC358768_DSICMD_WD2		0x0614
106 #define TC358768_DSICMD_WD3		0x0616
107 #define TC358768_DSI_EVENT		0x0620
108 #define TC358768_DSI_VSW		0x0622
109 #define TC358768_DSI_VBPR		0x0624
110 #define TC358768_DSI_VACT		0x0626
111 #define TC358768_DSI_HSW		0x0628
112 #define TC358768_DSI_HBPR		0x062A
113 #define TC358768_DSI_HACT		0x062C
114 
115 /* TC358768_DSI_CONTROL (0x040C) register */
116 #define TC358768_DSI_CONTROL_DIS_MODE	BIT(15)
117 #define TC358768_DSI_CONTROL_TXMD	BIT(7)
118 #define TC358768_DSI_CONTROL_HSCKMD	BIT(5)
119 #define TC358768_DSI_CONTROL_EOTDIS	BIT(0)
120 
121 /* TC358768_DSI_CONFW (0x0500) register */
122 #define TC358768_DSI_CONFW_MODE_SET	(5 << 29)
123 #define TC358768_DSI_CONFW_MODE_CLR	(6 << 29)
124 #define TC358768_DSI_CONFW_ADDR_DSI_CONTROL	(0x3 << 24)
125 
126 static const char * const tc358768_supplies[] = {
127 	"vddc", "vddmipi", "vddio"
128 };
129 
130 struct tc358768_dsi_output {
131 	struct mipi_dsi_device *dev;
132 	struct drm_panel *panel;
133 	struct drm_bridge *bridge;
134 };
135 
136 struct tc358768_priv {
137 	struct device *dev;
138 	struct regmap *regmap;
139 	struct gpio_desc *reset_gpio;
140 	struct regulator_bulk_data supplies[ARRAY_SIZE(tc358768_supplies)];
141 	struct clk *refclk;
142 	int enabled;
143 	int error;
144 
145 	struct mipi_dsi_host dsi_host;
146 	struct drm_bridge bridge;
147 	struct tc358768_dsi_output output;
148 
149 	u32 pd_lines; /* number of Parallel Port Input Data Lines */
150 	u32 dsi_lanes; /* number of DSI Lanes */
151 	u32 dsi_bpp; /* number of Bits Per Pixel over DSI */
152 
153 	/* Parameters for PLL programming */
154 	u32 fbd;	/* PLL feedback divider */
155 	u32 prd;	/* PLL input divider */
156 	u32 frs;	/* PLL Freqency range for HSCK (post divider) */
157 
158 	u32 dsiclk;	/* pll_clk / 2 */
159 };
160 
161 static inline struct tc358768_priv *dsi_host_to_tc358768(struct mipi_dsi_host
162 							 *host)
163 {
164 	return container_of(host, struct tc358768_priv, dsi_host);
165 }
166 
167 static inline struct tc358768_priv *bridge_to_tc358768(struct drm_bridge
168 						       *bridge)
169 {
170 	return container_of(bridge, struct tc358768_priv, bridge);
171 }
172 
173 static int tc358768_clear_error(struct tc358768_priv *priv)
174 {
175 	int ret = priv->error;
176 
177 	priv->error = 0;
178 	return ret;
179 }
180 
181 static void tc358768_write(struct tc358768_priv *priv, u32 reg, u32 val)
182 {
183 	/* work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */
184 	int tmpval = val;
185 	size_t count = 2;
186 
187 	if (priv->error)
188 		return;
189 
190 	/* 16-bit register? */
191 	if (reg < 0x100 || reg >= 0x600)
192 		count = 1;
193 
194 	priv->error = regmap_bulk_write(priv->regmap, reg, &tmpval, count);
195 }
196 
197 static void tc358768_read(struct tc358768_priv *priv, u32 reg, u32 *val)
198 {
199 	size_t count = 2;
200 
201 	if (priv->error)
202 		return;
203 
204 	/* 16-bit register? */
205 	if (reg < 0x100 || reg >= 0x600) {
206 		*val = 0;
207 		count = 1;
208 	}
209 
210 	priv->error = regmap_bulk_read(priv->regmap, reg, val, count);
211 }
212 
213 static void tc358768_update_bits(struct tc358768_priv *priv, u32 reg, u32 mask,
214 				 u32 val)
215 {
216 	u32 tmp, orig;
217 
218 	tc358768_read(priv, reg, &orig);
219 
220 	if (priv->error)
221 		return;
222 
223 	tmp = orig & ~mask;
224 	tmp |= val & mask;
225 	if (tmp != orig)
226 		tc358768_write(priv, reg, tmp);
227 }
228 
229 static int tc358768_sw_reset(struct tc358768_priv *priv)
230 {
231 	/* Assert Reset */
232 	tc358768_write(priv, TC358768_SYSCTL, 1);
233 	/* Release Reset, Exit Sleep */
234 	tc358768_write(priv, TC358768_SYSCTL, 0);
235 
236 	return tc358768_clear_error(priv);
237 }
238 
239 static void tc358768_hw_enable(struct tc358768_priv *priv)
240 {
241 	int ret;
242 
243 	if (priv->enabled)
244 		return;
245 
246 	ret = clk_prepare_enable(priv->refclk);
247 	if (ret < 0)
248 		dev_err(priv->dev, "error enabling refclk (%d)\n", ret);
249 
250 	ret = regulator_bulk_enable(ARRAY_SIZE(priv->supplies), priv->supplies);
251 	if (ret < 0)
252 		dev_err(priv->dev, "error enabling regulators (%d)\n", ret);
253 
254 	if (priv->reset_gpio)
255 		usleep_range(200, 300);
256 
257 	/*
258 	 * The RESX is active low (GPIO_ACTIVE_LOW).
259 	 * DEASSERT (value = 0) the reset_gpio to enable the chip
260 	 */
261 	gpiod_set_value_cansleep(priv->reset_gpio, 0);
262 
263 	/* wait for encoder clocks to stabilize */
264 	usleep_range(1000, 2000);
265 
266 	priv->enabled = true;
267 }
268 
269 static void tc358768_hw_disable(struct tc358768_priv *priv)
270 {
271 	int ret;
272 
273 	if (!priv->enabled)
274 		return;
275 
276 	/*
277 	 * The RESX is active low (GPIO_ACTIVE_LOW).
278 	 * ASSERT (value = 1) the reset_gpio to disable the chip
279 	 */
280 	gpiod_set_value_cansleep(priv->reset_gpio, 1);
281 
282 	ret = regulator_bulk_disable(ARRAY_SIZE(priv->supplies),
283 				     priv->supplies);
284 	if (ret < 0)
285 		dev_err(priv->dev, "error disabling regulators (%d)\n", ret);
286 
287 	clk_disable_unprepare(priv->refclk);
288 
289 	priv->enabled = false;
290 }
291 
292 static u32 tc358768_pll_to_pclk(struct tc358768_priv *priv, u32 pll_clk)
293 {
294 	return (u32)div_u64((u64)pll_clk * priv->dsi_lanes, priv->dsi_bpp);
295 }
296 
297 static u32 tc358768_pclk_to_pll(struct tc358768_priv *priv, u32 pclk)
298 {
299 	return (u32)div_u64((u64)pclk * priv->dsi_bpp, priv->dsi_lanes);
300 }
301 
302 static int tc358768_calc_pll(struct tc358768_priv *priv,
303 			     const struct drm_display_mode *mode,
304 			     bool verify_only)
305 {
306 	static const u32 frs_limits[] = {
307 		1000000000,
308 		500000000,
309 		250000000,
310 		125000000,
311 		62500000
312 	};
313 	unsigned long refclk;
314 	u32 prd, target_pll, i, max_pll, min_pll;
315 	u32 frs, best_diff, best_pll, best_prd, best_fbd;
316 
317 	target_pll = tc358768_pclk_to_pll(priv, mode->clock * 1000);
318 
319 	/* pll_clk = RefClk * [(FBD + 1)/ (PRD + 1)] * [1 / (2^FRS)] */
320 
321 	for (i = 0; i < ARRAY_SIZE(frs_limits); i++)
322 		if (target_pll >= frs_limits[i])
323 			break;
324 
325 	if (i == ARRAY_SIZE(frs_limits) || i == 0)
326 		return -EINVAL;
327 
328 	frs = i - 1;
329 	max_pll = frs_limits[i - 1];
330 	min_pll = frs_limits[i];
331 
332 	refclk = clk_get_rate(priv->refclk);
333 
334 	best_diff = UINT_MAX;
335 	best_pll = 0;
336 	best_prd = 0;
337 	best_fbd = 0;
338 
339 	for (prd = 0; prd < 16; ++prd) {
340 		u32 divisor = (prd + 1) * (1 << frs);
341 		u32 fbd;
342 
343 		for (fbd = 0; fbd < 512; ++fbd) {
344 			u32 pll, diff, pll_in;
345 
346 			pll = (u32)div_u64((u64)refclk * (fbd + 1), divisor);
347 
348 			if (pll >= max_pll || pll < min_pll)
349 				continue;
350 
351 			pll_in = (u32)div_u64((u64)refclk, prd + 1);
352 			if (pll_in < 4000000)
353 				continue;
354 
355 			diff = max(pll, target_pll) - min(pll, target_pll);
356 
357 			if (diff < best_diff) {
358 				best_diff = diff;
359 				best_pll = pll;
360 				best_prd = prd;
361 				best_fbd = fbd;
362 
363 				if (best_diff == 0)
364 					goto found;
365 			}
366 		}
367 	}
368 
369 	if (best_diff == UINT_MAX) {
370 		dev_err(priv->dev, "could not find suitable PLL setup\n");
371 		return -EINVAL;
372 	}
373 
374 found:
375 	if (verify_only)
376 		return 0;
377 
378 	priv->fbd = best_fbd;
379 	priv->prd = best_prd;
380 	priv->frs = frs;
381 	priv->dsiclk = best_pll / 2;
382 
383 	return 0;
384 }
385 
386 static int tc358768_dsi_host_attach(struct mipi_dsi_host *host,
387 				    struct mipi_dsi_device *dev)
388 {
389 	struct tc358768_priv *priv = dsi_host_to_tc358768(host);
390 	struct drm_bridge *bridge;
391 	struct drm_panel *panel;
392 	struct device_node *ep;
393 	int ret;
394 
395 	if (dev->lanes > 4) {
396 		dev_err(priv->dev, "unsupported number of data lanes(%u)\n",
397 			dev->lanes);
398 		return -EINVAL;
399 	}
400 
401 	/*
402 	 * tc358768 supports both Video and Pulse mode, but the driver only
403 	 * implements Video (event) mode currently
404 	 */
405 	if (!(dev->mode_flags & MIPI_DSI_MODE_VIDEO)) {
406 		dev_err(priv->dev, "Only MIPI_DSI_MODE_VIDEO is supported\n");
407 		return -ENOTSUPP;
408 	}
409 
410 	/*
411 	 * tc358768 supports RGB888, RGB666, RGB666_PACKED and RGB565, but only
412 	 * RGB888 is verified.
413 	 */
414 	if (dev->format != MIPI_DSI_FMT_RGB888) {
415 		dev_warn(priv->dev, "Only MIPI_DSI_FMT_RGB888 tested!\n");
416 		return -ENOTSUPP;
417 	}
418 
419 	ret = drm_of_find_panel_or_bridge(host->dev->of_node, 1, 0, &panel,
420 					  &bridge);
421 	if (ret)
422 		return ret;
423 
424 	if (panel) {
425 		bridge = drm_panel_bridge_add_typed(panel,
426 						    DRM_MODE_CONNECTOR_DSI);
427 		if (IS_ERR(bridge))
428 			return PTR_ERR(bridge);
429 	}
430 
431 	priv->output.dev = dev;
432 	priv->output.bridge = bridge;
433 	priv->output.panel = panel;
434 
435 	priv->dsi_lanes = dev->lanes;
436 	priv->dsi_bpp = mipi_dsi_pixel_format_to_bpp(dev->format);
437 
438 	/* get input ep (port0/endpoint0) */
439 	ret = -EINVAL;
440 	ep = of_graph_get_endpoint_by_regs(host->dev->of_node, 0, 0);
441 	if (ep) {
442 		ret = of_property_read_u32(ep, "data-lines", &priv->pd_lines);
443 
444 		of_node_put(ep);
445 	}
446 
447 	if (ret)
448 		priv->pd_lines = priv->dsi_bpp;
449 
450 	drm_bridge_add(&priv->bridge);
451 
452 	return 0;
453 }
454 
455 static int tc358768_dsi_host_detach(struct mipi_dsi_host *host,
456 				    struct mipi_dsi_device *dev)
457 {
458 	struct tc358768_priv *priv = dsi_host_to_tc358768(host);
459 
460 	drm_bridge_remove(&priv->bridge);
461 	if (priv->output.panel)
462 		drm_panel_bridge_remove(priv->output.bridge);
463 
464 	return 0;
465 }
466 
467 static ssize_t tc358768_dsi_host_transfer(struct mipi_dsi_host *host,
468 					  const struct mipi_dsi_msg *msg)
469 {
470 	struct tc358768_priv *priv = dsi_host_to_tc358768(host);
471 	struct mipi_dsi_packet packet;
472 	int ret;
473 
474 	if (!priv->enabled) {
475 		dev_err(priv->dev, "Bridge is not enabled\n");
476 		return -ENODEV;
477 	}
478 
479 	if (msg->rx_len) {
480 		dev_warn(priv->dev, "MIPI rx is not supported\n");
481 		return -ENOTSUPP;
482 	}
483 
484 	if (msg->tx_len > 8) {
485 		dev_warn(priv->dev, "Maximum 8 byte MIPI tx is supported\n");
486 		return -ENOTSUPP;
487 	}
488 
489 	ret = mipi_dsi_create_packet(&packet, msg);
490 	if (ret)
491 		return ret;
492 
493 	if (mipi_dsi_packet_format_is_short(msg->type)) {
494 		tc358768_write(priv, TC358768_DSICMD_TYPE,
495 			       (0x10 << 8) | (packet.header[0] & 0x3f));
496 		tc358768_write(priv, TC358768_DSICMD_WC, 0);
497 		tc358768_write(priv, TC358768_DSICMD_WD0,
498 			       (packet.header[2] << 8) | packet.header[1]);
499 	} else {
500 		int i;
501 
502 		tc358768_write(priv, TC358768_DSICMD_TYPE,
503 			       (0x40 << 8) | (packet.header[0] & 0x3f));
504 		tc358768_write(priv, TC358768_DSICMD_WC, packet.payload_length);
505 		for (i = 0; i < packet.payload_length; i += 2) {
506 			u16 val = packet.payload[i];
507 
508 			if (i + 1 < packet.payload_length)
509 				val |= packet.payload[i + 1] << 8;
510 
511 			tc358768_write(priv, TC358768_DSICMD_WD0 + i, val);
512 		}
513 	}
514 
515 	/* start transfer */
516 	tc358768_write(priv, TC358768_DSICMD_TX, 1);
517 
518 	ret = tc358768_clear_error(priv);
519 	if (ret)
520 		dev_warn(priv->dev, "Software disable failed: %d\n", ret);
521 	else
522 		ret = packet.size;
523 
524 	return ret;
525 }
526 
527 static const struct mipi_dsi_host_ops tc358768_dsi_host_ops = {
528 	.attach = tc358768_dsi_host_attach,
529 	.detach = tc358768_dsi_host_detach,
530 	.transfer = tc358768_dsi_host_transfer,
531 };
532 
533 static int tc358768_bridge_attach(struct drm_bridge *bridge,
534 				  enum drm_bridge_attach_flags flags)
535 {
536 	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
537 
538 	if (!drm_core_check_feature(bridge->dev, DRIVER_ATOMIC)) {
539 		dev_err(priv->dev, "needs atomic updates support\n");
540 		return -ENOTSUPP;
541 	}
542 
543 	return drm_bridge_attach(bridge->encoder, priv->output.bridge, bridge,
544 				 flags);
545 }
546 
547 static enum drm_mode_status
548 tc358768_bridge_mode_valid(struct drm_bridge *bridge,
549 			   const struct drm_display_info *info,
550 			   const struct drm_display_mode *mode)
551 {
552 	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
553 
554 	if (tc358768_calc_pll(priv, mode, true))
555 		return MODE_CLOCK_RANGE;
556 
557 	return MODE_OK;
558 }
559 
560 static void tc358768_bridge_disable(struct drm_bridge *bridge)
561 {
562 	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
563 	int ret;
564 
565 	/* set FrmStop */
566 	tc358768_update_bits(priv, TC358768_PP_MISC, BIT(15), BIT(15));
567 
568 	/* wait at least for one frame */
569 	msleep(50);
570 
571 	/* clear PP_en */
572 	tc358768_update_bits(priv, TC358768_CONFCTL, BIT(6), 0);
573 
574 	/* set RstPtr */
575 	tc358768_update_bits(priv, TC358768_PP_MISC, BIT(14), BIT(14));
576 
577 	ret = tc358768_clear_error(priv);
578 	if (ret)
579 		dev_warn(priv->dev, "Software disable failed: %d\n", ret);
580 }
581 
582 static void tc358768_bridge_post_disable(struct drm_bridge *bridge)
583 {
584 	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
585 
586 	tc358768_hw_disable(priv);
587 }
588 
589 static int tc358768_setup_pll(struct tc358768_priv *priv,
590 			      const struct drm_display_mode *mode)
591 {
592 	u32 fbd, prd, frs;
593 	int ret;
594 
595 	ret = tc358768_calc_pll(priv, mode, false);
596 	if (ret) {
597 		dev_err(priv->dev, "PLL calculation failed: %d\n", ret);
598 		return ret;
599 	}
600 
601 	fbd = priv->fbd;
602 	prd = priv->prd;
603 	frs = priv->frs;
604 
605 	dev_dbg(priv->dev, "PLL: refclk %lu, fbd %u, prd %u, frs %u\n",
606 		clk_get_rate(priv->refclk), fbd, prd, frs);
607 	dev_dbg(priv->dev, "PLL: pll_clk: %u, DSIClk %u, DSIByteClk %u\n",
608 		priv->dsiclk * 2, priv->dsiclk, priv->dsiclk / 4);
609 	dev_dbg(priv->dev, "PLL: pclk %u (panel: %u)\n",
610 		tc358768_pll_to_pclk(priv, priv->dsiclk * 2),
611 		mode->clock * 1000);
612 
613 	/* PRD[15:12] FBD[8:0] */
614 	tc358768_write(priv, TC358768_PLLCTL0, (prd << 12) | fbd);
615 
616 	/* FRS[11:10] LBWS[9:8] CKEN[4] RESETB[1] EN[0] */
617 	tc358768_write(priv, TC358768_PLLCTL1,
618 		       (frs << 10) | (0x2 << 8) | BIT(1) | BIT(0));
619 
620 	/* wait for lock */
621 	usleep_range(1000, 2000);
622 
623 	/* FRS[11:10] LBWS[9:8] CKEN[4] PLL_CKEN[4] RESETB[1] EN[0] */
624 	tc358768_write(priv, TC358768_PLLCTL1,
625 		       (frs << 10) | (0x2 << 8) | BIT(4) | BIT(1) | BIT(0));
626 
627 	return tc358768_clear_error(priv);
628 }
629 
630 #define TC358768_PRECISION	1000
631 static u32 tc358768_ns_to_cnt(u32 ns, u32 period_nsk)
632 {
633 	return (ns * TC358768_PRECISION + period_nsk) / period_nsk;
634 }
635 
636 static u32 tc358768_to_ns(u32 nsk)
637 {
638 	return (nsk / TC358768_PRECISION);
639 }
640 
641 static void tc358768_bridge_pre_enable(struct drm_bridge *bridge)
642 {
643 	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
644 	struct mipi_dsi_device *dsi_dev = priv->output.dev;
645 	unsigned long mode_flags = dsi_dev->mode_flags;
646 	u32 val, val2, lptxcnt, hact, data_type;
647 	s32 raw_val;
648 	const struct drm_display_mode *mode;
649 	u32 dsibclk_nsk, dsiclk_nsk, ui_nsk;
650 	u32 dsiclk, dsibclk, video_start;
651 	const u32 internal_delay = 40;
652 	int ret, i;
653 
654 	if (mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) {
655 		dev_warn_once(priv->dev, "Non-continuous mode unimplemented, falling back to continuous\n");
656 		mode_flags &= ~MIPI_DSI_CLOCK_NON_CONTINUOUS;
657 	}
658 
659 	tc358768_hw_enable(priv);
660 
661 	ret = tc358768_sw_reset(priv);
662 	if (ret) {
663 		dev_err(priv->dev, "Software reset failed: %d\n", ret);
664 		tc358768_hw_disable(priv);
665 		return;
666 	}
667 
668 	mode = &bridge->encoder->crtc->state->adjusted_mode;
669 	ret = tc358768_setup_pll(priv, mode);
670 	if (ret) {
671 		dev_err(priv->dev, "PLL setup failed: %d\n", ret);
672 		tc358768_hw_disable(priv);
673 		return;
674 	}
675 
676 	dsiclk = priv->dsiclk;
677 	dsibclk = dsiclk / 4;
678 
679 	/* Data Format Control Register */
680 	val = BIT(2) | BIT(1) | BIT(0); /* rdswap_en | dsitx_en | txdt_en */
681 	switch (dsi_dev->format) {
682 	case MIPI_DSI_FMT_RGB888:
683 		val |= (0x3 << 4);
684 		hact = mode->hdisplay * 3;
685 		video_start = (mode->htotal - mode->hsync_start) * 3;
686 		data_type = MIPI_DSI_PACKED_PIXEL_STREAM_24;
687 		break;
688 	case MIPI_DSI_FMT_RGB666:
689 		val |= (0x4 << 4);
690 		hact = mode->hdisplay * 3;
691 		video_start = (mode->htotal - mode->hsync_start) * 3;
692 		data_type = MIPI_DSI_PACKED_PIXEL_STREAM_18;
693 		break;
694 
695 	case MIPI_DSI_FMT_RGB666_PACKED:
696 		val |= (0x4 << 4) | BIT(3);
697 		hact = mode->hdisplay * 18 / 8;
698 		video_start = (mode->htotal - mode->hsync_start) * 18 / 8;
699 		data_type = MIPI_DSI_PIXEL_STREAM_3BYTE_18;
700 		break;
701 
702 	case MIPI_DSI_FMT_RGB565:
703 		val |= (0x5 << 4);
704 		hact = mode->hdisplay * 2;
705 		video_start = (mode->htotal - mode->hsync_start) * 2;
706 		data_type = MIPI_DSI_PACKED_PIXEL_STREAM_16;
707 		break;
708 	default:
709 		dev_err(priv->dev, "Invalid data format (%u)\n",
710 			dsi_dev->format);
711 		tc358768_hw_disable(priv);
712 		return;
713 	}
714 
715 	/* VSDly[9:0] */
716 	video_start = max(video_start, internal_delay + 1) - internal_delay;
717 	tc358768_write(priv, TC358768_VSDLY, video_start);
718 
719 	tc358768_write(priv, TC358768_DATAFMT, val);
720 	tc358768_write(priv, TC358768_DSITX_DT, data_type);
721 
722 	/* Enable D-PHY (HiZ->LP11) */
723 	tc358768_write(priv, TC358768_CLW_CNTRL, 0x0000);
724 	/* Enable lanes */
725 	for (i = 0; i < dsi_dev->lanes; i++)
726 		tc358768_write(priv, TC358768_D0W_CNTRL + i * 4, 0x0000);
727 
728 	/* DSI Timings */
729 	dsibclk_nsk = (u32)div_u64((u64)1000000000 * TC358768_PRECISION,
730 				  dsibclk);
731 	dsiclk_nsk = (u32)div_u64((u64)1000000000 * TC358768_PRECISION, dsiclk);
732 	ui_nsk = dsiclk_nsk / 2;
733 	dev_dbg(priv->dev, "dsiclk_nsk: %u\n", dsiclk_nsk);
734 	dev_dbg(priv->dev, "ui_nsk: %u\n", ui_nsk);
735 	dev_dbg(priv->dev, "dsibclk_nsk: %u\n", dsibclk_nsk);
736 
737 	/* LP11 > 100us for D-PHY Rx Init */
738 	val = tc358768_ns_to_cnt(100 * 1000, dsibclk_nsk) - 1;
739 	dev_dbg(priv->dev, "LINEINITCNT: 0x%x\n", val);
740 	tc358768_write(priv, TC358768_LINEINITCNT, val);
741 
742 	/* LPTimeCnt > 50ns */
743 	val = tc358768_ns_to_cnt(50, dsibclk_nsk) - 1;
744 	lptxcnt = val;
745 	dev_dbg(priv->dev, "LPTXTIMECNT: 0x%x\n", val);
746 	tc358768_write(priv, TC358768_LPTXTIMECNT, val);
747 
748 	/* 38ns < TCLK_PREPARE < 95ns */
749 	val = tc358768_ns_to_cnt(65, dsibclk_nsk) - 1;
750 	/* TCLK_PREPARE + TCLK_ZERO > 300ns */
751 	val2 = tc358768_ns_to_cnt(300 - tc358768_to_ns(2 * ui_nsk),
752 				  dsibclk_nsk) - 2;
753 	val |= val2 << 8;
754 	dev_dbg(priv->dev, "TCLK_HEADERCNT: 0x%x\n", val);
755 	tc358768_write(priv, TC358768_TCLK_HEADERCNT, val);
756 
757 	/* TCLK_TRAIL > 60ns AND TEOT <= 105 ns + 12*UI */
758 	raw_val = tc358768_ns_to_cnt(60 + tc358768_to_ns(2 * ui_nsk), dsibclk_nsk) - 5;
759 	val = clamp(raw_val, 0, 127);
760 	dev_dbg(priv->dev, "TCLK_TRAILCNT: 0x%x\n", val);
761 	tc358768_write(priv, TC358768_TCLK_TRAILCNT, val);
762 
763 	/* 40ns + 4*UI < THS_PREPARE < 85ns + 6*UI */
764 	val = 50 + tc358768_to_ns(4 * ui_nsk);
765 	val = tc358768_ns_to_cnt(val, dsibclk_nsk) - 1;
766 	/* THS_PREPARE + THS_ZERO > 145ns + 10*UI */
767 	raw_val = tc358768_ns_to_cnt(145 - tc358768_to_ns(3 * ui_nsk), dsibclk_nsk) - 10;
768 	val2 = clamp(raw_val, 0, 127);
769 	val |= val2 << 8;
770 	dev_dbg(priv->dev, "THS_HEADERCNT: 0x%x\n", val);
771 	tc358768_write(priv, TC358768_THS_HEADERCNT, val);
772 
773 	/* TWAKEUP > 1ms in lptxcnt steps */
774 	val = tc358768_ns_to_cnt(1020000, dsibclk_nsk);
775 	val = val / (lptxcnt + 1) - 1;
776 	dev_dbg(priv->dev, "TWAKEUP: 0x%x\n", val);
777 	tc358768_write(priv, TC358768_TWAKEUP, val);
778 
779 	/* TCLK_POSTCNT > 60ns + 52*UI */
780 	val = tc358768_ns_to_cnt(60 + tc358768_to_ns(52 * ui_nsk),
781 				 dsibclk_nsk) - 3;
782 	dev_dbg(priv->dev, "TCLK_POSTCNT: 0x%x\n", val);
783 	tc358768_write(priv, TC358768_TCLK_POSTCNT, val);
784 
785 	/* max(60ns + 4*UI, 8*UI) < THS_TRAILCNT < 105ns + 12*UI */
786 	raw_val = tc358768_ns_to_cnt(60 + tc358768_to_ns(18 * ui_nsk),
787 				     dsibclk_nsk) - 4;
788 	val = clamp(raw_val, 0, 15);
789 	dev_dbg(priv->dev, "THS_TRAILCNT: 0x%x\n", val);
790 	tc358768_write(priv, TC358768_THS_TRAILCNT, val);
791 
792 	val = BIT(0);
793 	for (i = 0; i < dsi_dev->lanes; i++)
794 		val |= BIT(i + 1);
795 	tc358768_write(priv, TC358768_HSTXVREGEN, val);
796 
797 	if (!(mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS))
798 		tc358768_write(priv, TC358768_TXOPTIONCNTRL, 0x1);
799 
800 	/* TXTAGOCNT[26:16] RXTASURECNT[10:0] */
801 	val = tc358768_to_ns((lptxcnt + 1) * dsibclk_nsk * 4);
802 	val = tc358768_ns_to_cnt(val, dsibclk_nsk) / 4 - 1;
803 	val2 = tc358768_ns_to_cnt(tc358768_to_ns((lptxcnt + 1) * dsibclk_nsk),
804 				  dsibclk_nsk) - 2;
805 	val = val << 16 | val2;
806 	dev_dbg(priv->dev, "BTACNTRL1: 0x%x\n", val);
807 	tc358768_write(priv, TC358768_BTACNTRL1, val);
808 
809 	/* START[0] */
810 	tc358768_write(priv, TC358768_STARTCNTRL, 1);
811 
812 	if (dsi_dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) {
813 		/* Set pulse mode */
814 		tc358768_write(priv, TC358768_DSI_EVENT, 0);
815 
816 		/* vact */
817 		tc358768_write(priv, TC358768_DSI_VACT, mode->vdisplay);
818 
819 		/* vsw */
820 		tc358768_write(priv, TC358768_DSI_VSW,
821 			       mode->vsync_end - mode->vsync_start);
822 		/* vbp */
823 		tc358768_write(priv, TC358768_DSI_VBPR,
824 			       mode->vtotal - mode->vsync_end);
825 
826 		/* hsw * byteclk * ndl / pclk */
827 		val = (u32)div_u64((mode->hsync_end - mode->hsync_start) *
828 				   ((u64)priv->dsiclk / 4) * priv->dsi_lanes,
829 				   mode->clock * 1000);
830 		tc358768_write(priv, TC358768_DSI_HSW, val);
831 
832 		/* hbp * byteclk * ndl / pclk */
833 		val = (u32)div_u64((mode->htotal - mode->hsync_end) *
834 				   ((u64)priv->dsiclk / 4) * priv->dsi_lanes,
835 				   mode->clock * 1000);
836 		tc358768_write(priv, TC358768_DSI_HBPR, val);
837 	} else {
838 		/* Set event mode */
839 		tc358768_write(priv, TC358768_DSI_EVENT, 1);
840 
841 		/* vact */
842 		tc358768_write(priv, TC358768_DSI_VACT, mode->vdisplay);
843 
844 		/* vsw (+ vbp) */
845 		tc358768_write(priv, TC358768_DSI_VSW,
846 			       mode->vtotal - mode->vsync_start);
847 		/* vbp (not used in event mode) */
848 		tc358768_write(priv, TC358768_DSI_VBPR, 0);
849 
850 		/* (hsw + hbp) * byteclk * ndl / pclk */
851 		val = (u32)div_u64((mode->htotal - mode->hsync_start) *
852 				   ((u64)priv->dsiclk / 4) * priv->dsi_lanes,
853 				   mode->clock * 1000);
854 		tc358768_write(priv, TC358768_DSI_HSW, val);
855 
856 		/* hbp (not used in event mode) */
857 		tc358768_write(priv, TC358768_DSI_HBPR, 0);
858 	}
859 
860 	/* hact (bytes) */
861 	tc358768_write(priv, TC358768_DSI_HACT, hact);
862 
863 	/* VSYNC polarity */
864 	if (!(mode->flags & DRM_MODE_FLAG_NVSYNC))
865 		tc358768_update_bits(priv, TC358768_CONFCTL, BIT(5), BIT(5));
866 	/* HSYNC polarity */
867 	if (mode->flags & DRM_MODE_FLAG_PHSYNC)
868 		tc358768_update_bits(priv, TC358768_PP_MISC, BIT(0), BIT(0));
869 
870 	/* Start DSI Tx */
871 	tc358768_write(priv, TC358768_DSI_START, 0x1);
872 
873 	/* Configure DSI_Control register */
874 	val = TC358768_DSI_CONFW_MODE_CLR | TC358768_DSI_CONFW_ADDR_DSI_CONTROL;
875 	val |= TC358768_DSI_CONTROL_TXMD | TC358768_DSI_CONTROL_HSCKMD |
876 	       0x3 << 1 | TC358768_DSI_CONTROL_EOTDIS;
877 	tc358768_write(priv, TC358768_DSI_CONFW, val);
878 
879 	val = TC358768_DSI_CONFW_MODE_SET | TC358768_DSI_CONFW_ADDR_DSI_CONTROL;
880 	val |= (dsi_dev->lanes - 1) << 1;
881 
882 	val |= TC358768_DSI_CONTROL_TXMD;
883 
884 	if (!(mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS))
885 		val |= TC358768_DSI_CONTROL_HSCKMD;
886 
887 	if (dsi_dev->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET)
888 		val |= TC358768_DSI_CONTROL_EOTDIS;
889 
890 	tc358768_write(priv, TC358768_DSI_CONFW, val);
891 
892 	val = TC358768_DSI_CONFW_MODE_CLR | TC358768_DSI_CONFW_ADDR_DSI_CONTROL;
893 	val |= TC358768_DSI_CONTROL_DIS_MODE; /* DSI mode */
894 	tc358768_write(priv, TC358768_DSI_CONFW, val);
895 
896 	ret = tc358768_clear_error(priv);
897 	if (ret) {
898 		dev_err(priv->dev, "Bridge pre_enable failed: %d\n", ret);
899 		tc358768_bridge_disable(bridge);
900 		tc358768_bridge_post_disable(bridge);
901 	}
902 }
903 
904 static void tc358768_bridge_enable(struct drm_bridge *bridge)
905 {
906 	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
907 	int ret;
908 
909 	if (!priv->enabled) {
910 		dev_err(priv->dev, "Bridge is not enabled\n");
911 		return;
912 	}
913 
914 	/* clear FrmStop and RstPtr */
915 	tc358768_update_bits(priv, TC358768_PP_MISC, 0x3 << 14, 0);
916 
917 	/* set PP_en */
918 	tc358768_update_bits(priv, TC358768_CONFCTL, BIT(6), BIT(6));
919 
920 	ret = tc358768_clear_error(priv);
921 	if (ret) {
922 		dev_err(priv->dev, "Bridge enable failed: %d\n", ret);
923 		tc358768_bridge_disable(bridge);
924 		tc358768_bridge_post_disable(bridge);
925 	}
926 }
927 
928 #define MAX_INPUT_SEL_FORMATS	1
929 
930 static u32 *
931 tc358768_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
932 				   struct drm_bridge_state *bridge_state,
933 				   struct drm_crtc_state *crtc_state,
934 				   struct drm_connector_state *conn_state,
935 				   u32 output_fmt,
936 				   unsigned int *num_input_fmts)
937 {
938 	struct tc358768_priv *priv = bridge_to_tc358768(bridge);
939 	u32 *input_fmts;
940 
941 	*num_input_fmts = 0;
942 
943 	input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
944 			     GFP_KERNEL);
945 	if (!input_fmts)
946 		return NULL;
947 
948 	switch (priv->pd_lines) {
949 	case 16:
950 		input_fmts[0] = MEDIA_BUS_FMT_RGB565_1X16;
951 		break;
952 	case 18:
953 		input_fmts[0] = MEDIA_BUS_FMT_RGB666_1X18;
954 		break;
955 	default:
956 	case 24:
957 		input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
958 		break;
959 	}
960 
961 	*num_input_fmts = MAX_INPUT_SEL_FORMATS;
962 
963 	return input_fmts;
964 }
965 
966 static const struct drm_bridge_funcs tc358768_bridge_funcs = {
967 	.attach = tc358768_bridge_attach,
968 	.mode_valid = tc358768_bridge_mode_valid,
969 	.pre_enable = tc358768_bridge_pre_enable,
970 	.enable = tc358768_bridge_enable,
971 	.disable = tc358768_bridge_disable,
972 	.post_disable = tc358768_bridge_post_disable,
973 
974 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
975 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
976 	.atomic_reset = drm_atomic_helper_bridge_reset,
977 	.atomic_get_input_bus_fmts = tc358768_atomic_get_input_bus_fmts,
978 };
979 
980 static const struct drm_bridge_timings default_tc358768_timings = {
981 	.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE
982 		 | DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE
983 		 | DRM_BUS_FLAG_DE_HIGH,
984 };
985 
986 static bool tc358768_is_reserved_reg(unsigned int reg)
987 {
988 	switch (reg) {
989 	case 0x114 ... 0x13f:
990 	case 0x200:
991 	case 0x20c:
992 	case 0x400 ... 0x408:
993 	case 0x41c ... 0x42f:
994 		return true;
995 	default:
996 		return false;
997 	}
998 }
999 
1000 static bool tc358768_writeable_reg(struct device *dev, unsigned int reg)
1001 {
1002 	if (tc358768_is_reserved_reg(reg))
1003 		return false;
1004 
1005 	switch (reg) {
1006 	case TC358768_CHIPID:
1007 	case TC358768_FIFOSTATUS:
1008 	case TC358768_DSITXSTATUS ... (TC358768_DSITXSTATUS + 2):
1009 	case TC358768_DSI_CONTROL ... (TC358768_DSI_INT_ENA + 2):
1010 	case TC358768_DSICMD_RDFIFO ... (TC358768_DSI_ERR_HALT + 2):
1011 		return false;
1012 	default:
1013 		return true;
1014 	}
1015 }
1016 
1017 static bool tc358768_readable_reg(struct device *dev, unsigned int reg)
1018 {
1019 	if (tc358768_is_reserved_reg(reg))
1020 		return false;
1021 
1022 	switch (reg) {
1023 	case TC358768_STARTCNTRL:
1024 	case TC358768_DSI_CONFW ... (TC358768_DSI_CONFW + 2):
1025 	case TC358768_DSI_INT_CLR ... (TC358768_DSI_INT_CLR + 2):
1026 	case TC358768_DSI_START ... (TC358768_DSI_START + 2):
1027 	case TC358768_DBG_DATA:
1028 		return false;
1029 	default:
1030 		return true;
1031 	}
1032 }
1033 
1034 static const struct regmap_config tc358768_regmap_config = {
1035 	.name = "tc358768",
1036 	.reg_bits = 16,
1037 	.val_bits = 16,
1038 	.max_register = TC358768_DSI_HACT,
1039 	.cache_type = REGCACHE_NONE,
1040 	.writeable_reg = tc358768_writeable_reg,
1041 	.readable_reg = tc358768_readable_reg,
1042 	.reg_format_endian = REGMAP_ENDIAN_BIG,
1043 	.val_format_endian = REGMAP_ENDIAN_BIG,
1044 };
1045 
1046 static const struct i2c_device_id tc358768_i2c_ids[] = {
1047 	{ "tc358768", 0 },
1048 	{ "tc358778", 0 },
1049 	{ }
1050 };
1051 MODULE_DEVICE_TABLE(i2c, tc358768_i2c_ids);
1052 
1053 static const struct of_device_id tc358768_of_ids[] = {
1054 	{ .compatible = "toshiba,tc358768", },
1055 	{ .compatible = "toshiba,tc358778", },
1056 	{ }
1057 };
1058 MODULE_DEVICE_TABLE(of, tc358768_of_ids);
1059 
1060 static int tc358768_get_regulators(struct tc358768_priv *priv)
1061 {
1062 	int i, ret;
1063 
1064 	for (i = 0; i < ARRAY_SIZE(priv->supplies); ++i)
1065 		priv->supplies[i].supply = tc358768_supplies[i];
1066 
1067 	ret = devm_regulator_bulk_get(priv->dev, ARRAY_SIZE(priv->supplies),
1068 				      priv->supplies);
1069 	if (ret < 0)
1070 		dev_err(priv->dev, "failed to get regulators: %d\n", ret);
1071 
1072 	return ret;
1073 }
1074 
1075 static int tc358768_i2c_probe(struct i2c_client *client)
1076 {
1077 	struct tc358768_priv *priv;
1078 	struct device *dev = &client->dev;
1079 	struct device_node *np = dev->of_node;
1080 	int ret;
1081 
1082 	if (!np)
1083 		return -ENODEV;
1084 
1085 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
1086 	if (!priv)
1087 		return -ENOMEM;
1088 
1089 	dev_set_drvdata(dev, priv);
1090 	priv->dev = dev;
1091 
1092 	ret = tc358768_get_regulators(priv);
1093 	if (ret)
1094 		return ret;
1095 
1096 	priv->refclk = devm_clk_get(dev, "refclk");
1097 	if (IS_ERR(priv->refclk))
1098 		return PTR_ERR(priv->refclk);
1099 
1100 	/*
1101 	 * RESX is low active, to disable tc358768 initially (keep in reset)
1102 	 * the gpio line must be LOW. This is the ASSERTED state of
1103 	 * GPIO_ACTIVE_LOW (GPIOD_OUT_HIGH == ASSERTED).
1104 	 */
1105 	priv->reset_gpio  = devm_gpiod_get_optional(dev, "reset",
1106 						    GPIOD_OUT_HIGH);
1107 	if (IS_ERR(priv->reset_gpio))
1108 		return PTR_ERR(priv->reset_gpio);
1109 
1110 	priv->regmap = devm_regmap_init_i2c(client, &tc358768_regmap_config);
1111 	if (IS_ERR(priv->regmap)) {
1112 		dev_err(dev, "Failed to init regmap\n");
1113 		return PTR_ERR(priv->regmap);
1114 	}
1115 
1116 	priv->dsi_host.dev = dev;
1117 	priv->dsi_host.ops = &tc358768_dsi_host_ops;
1118 
1119 	priv->bridge.funcs = &tc358768_bridge_funcs;
1120 	priv->bridge.timings = &default_tc358768_timings;
1121 	priv->bridge.of_node = np;
1122 
1123 	i2c_set_clientdata(client, priv);
1124 
1125 	return mipi_dsi_host_register(&priv->dsi_host);
1126 }
1127 
1128 static void tc358768_i2c_remove(struct i2c_client *client)
1129 {
1130 	struct tc358768_priv *priv = i2c_get_clientdata(client);
1131 
1132 	mipi_dsi_host_unregister(&priv->dsi_host);
1133 }
1134 
1135 static struct i2c_driver tc358768_driver = {
1136 	.driver = {
1137 		.name = "tc358768",
1138 		.of_match_table = tc358768_of_ids,
1139 	},
1140 	.id_table = tc358768_i2c_ids,
1141 	.probe = tc358768_i2c_probe,
1142 	.remove	= tc358768_i2c_remove,
1143 };
1144 module_i2c_driver(tc358768_driver);
1145 
1146 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
1147 MODULE_DESCRIPTION("TC358768AXBG/TC358778XBG DSI bridge");
1148 MODULE_LICENSE("GPL v2");
1149