1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
4  * Copyright (C) STMicroelectronics SA 2017
5  *
6  * Modified by Philippe Cornu <philippe.cornu@st.com>
7  * This generic Synopsys DesignWare MIPI DSI host driver is based on the
8  * Rockchip version from rockchip/dw-mipi-dsi.c with phy & bridge APIs.
9  */
10 
11 #include <linux/clk.h>
12 #include <linux/component.h>
13 #include <linux/debugfs.h>
14 #include <linux/iopoll.h>
15 #include <linux/module.h>
16 #include <linux/of_device.h>
17 #include <linux/pm_runtime.h>
18 #include <linux/reset.h>
19 
20 #include <video/mipi_display.h>
21 
22 #include <drm/bridge/dw_mipi_dsi.h>
23 #include <drm/drm_atomic_helper.h>
24 #include <drm/drm_bridge.h>
25 #include <drm/drm_crtc.h>
26 #include <drm/drm_mipi_dsi.h>
27 #include <drm/drm_modes.h>
28 #include <drm/drm_of.h>
29 #include <drm/drm_print.h>
30 #include <drm/drm_probe_helper.h>
31 
32 #define HWVER_131			0x31333100	/* IP version 1.31 */
33 
34 #define DSI_VERSION			0x00
35 #define VERSION				GENMASK(31, 8)
36 
37 #define DSI_PWR_UP			0x04
38 #define RESET				0
39 #define POWERUP				BIT(0)
40 
41 #define DSI_CLKMGR_CFG			0x08
42 #define TO_CLK_DIVISION(div)		(((div) & 0xff) << 8)
43 #define TX_ESC_CLK_DIVISION(div)	((div) & 0xff)
44 
45 #define DSI_DPI_VCID			0x0c
46 #define DPI_VCID(vcid)			((vcid) & 0x3)
47 
48 #define DSI_DPI_COLOR_CODING		0x10
49 #define LOOSELY18_EN			BIT(8)
50 #define DPI_COLOR_CODING_16BIT_1	0x0
51 #define DPI_COLOR_CODING_16BIT_2	0x1
52 #define DPI_COLOR_CODING_16BIT_3	0x2
53 #define DPI_COLOR_CODING_18BIT_1	0x3
54 #define DPI_COLOR_CODING_18BIT_2	0x4
55 #define DPI_COLOR_CODING_24BIT		0x5
56 
57 #define DSI_DPI_CFG_POL			0x14
58 #define COLORM_ACTIVE_LOW		BIT(4)
59 #define SHUTD_ACTIVE_LOW		BIT(3)
60 #define HSYNC_ACTIVE_LOW		BIT(2)
61 #define VSYNC_ACTIVE_LOW		BIT(1)
62 #define DATAEN_ACTIVE_LOW		BIT(0)
63 
64 #define DSI_DPI_LP_CMD_TIM		0x18
65 #define OUTVACT_LPCMD_TIME(p)		(((p) & 0xff) << 16)
66 #define INVACT_LPCMD_TIME(p)		((p) & 0xff)
67 
68 #define DSI_DBI_VCID			0x1c
69 #define DSI_DBI_CFG			0x20
70 #define DSI_DBI_PARTITIONING_EN		0x24
71 #define DSI_DBI_CMDSIZE			0x28
72 
73 #define DSI_PCKHDL_CFG			0x2c
74 #define CRC_RX_EN			BIT(4)
75 #define ECC_RX_EN			BIT(3)
76 #define BTA_EN				BIT(2)
77 #define EOTP_RX_EN			BIT(1)
78 #define EOTP_TX_EN			BIT(0)
79 
80 #define DSI_GEN_VCID			0x30
81 
82 #define DSI_MODE_CFG			0x34
83 #define ENABLE_VIDEO_MODE		0
84 #define ENABLE_CMD_MODE			BIT(0)
85 
86 #define DSI_VID_MODE_CFG		0x38
87 #define ENABLE_LOW_POWER		(0x3f << 8)
88 #define ENABLE_LOW_POWER_MASK		(0x3f << 8)
89 #define VID_MODE_TYPE_NON_BURST_SYNC_PULSES	0x0
90 #define VID_MODE_TYPE_NON_BURST_SYNC_EVENTS	0x1
91 #define VID_MODE_TYPE_BURST			0x2
92 #define VID_MODE_TYPE_MASK			0x3
93 #define VID_MODE_VPG_ENABLE		BIT(16)
94 #define VID_MODE_VPG_HORIZONTAL		BIT(24)
95 
96 #define DSI_VID_PKT_SIZE		0x3c
97 #define VID_PKT_SIZE(p)			((p) & 0x3fff)
98 
99 #define DSI_VID_NUM_CHUNKS		0x40
100 #define VID_NUM_CHUNKS(c)		((c) & 0x1fff)
101 
102 #define DSI_VID_NULL_SIZE		0x44
103 #define VID_NULL_SIZE(b)		((b) & 0x1fff)
104 
105 #define DSI_VID_HSA_TIME		0x48
106 #define DSI_VID_HBP_TIME		0x4c
107 #define DSI_VID_HLINE_TIME		0x50
108 #define DSI_VID_VSA_LINES		0x54
109 #define DSI_VID_VBP_LINES		0x58
110 #define DSI_VID_VFP_LINES		0x5c
111 #define DSI_VID_VACTIVE_LINES		0x60
112 #define DSI_EDPI_CMD_SIZE		0x64
113 
114 #define DSI_CMD_MODE_CFG		0x68
115 #define MAX_RD_PKT_SIZE_LP		BIT(24)
116 #define DCS_LW_TX_LP			BIT(19)
117 #define DCS_SR_0P_TX_LP			BIT(18)
118 #define DCS_SW_1P_TX_LP			BIT(17)
119 #define DCS_SW_0P_TX_LP			BIT(16)
120 #define GEN_LW_TX_LP			BIT(14)
121 #define GEN_SR_2P_TX_LP			BIT(13)
122 #define GEN_SR_1P_TX_LP			BIT(12)
123 #define GEN_SR_0P_TX_LP			BIT(11)
124 #define GEN_SW_2P_TX_LP			BIT(10)
125 #define GEN_SW_1P_TX_LP			BIT(9)
126 #define GEN_SW_0P_TX_LP			BIT(8)
127 #define ACK_RQST_EN			BIT(1)
128 #define TEAR_FX_EN			BIT(0)
129 
130 #define CMD_MODE_ALL_LP			(MAX_RD_PKT_SIZE_LP | \
131 					 DCS_LW_TX_LP | \
132 					 DCS_SR_0P_TX_LP | \
133 					 DCS_SW_1P_TX_LP | \
134 					 DCS_SW_0P_TX_LP | \
135 					 GEN_LW_TX_LP | \
136 					 GEN_SR_2P_TX_LP | \
137 					 GEN_SR_1P_TX_LP | \
138 					 GEN_SR_0P_TX_LP | \
139 					 GEN_SW_2P_TX_LP | \
140 					 GEN_SW_1P_TX_LP | \
141 					 GEN_SW_0P_TX_LP)
142 
143 #define DSI_GEN_HDR			0x6c
144 #define DSI_GEN_PLD_DATA		0x70
145 
146 #define DSI_CMD_PKT_STATUS		0x74
147 #define GEN_RD_CMD_BUSY			BIT(6)
148 #define GEN_PLD_R_FULL			BIT(5)
149 #define GEN_PLD_R_EMPTY			BIT(4)
150 #define GEN_PLD_W_FULL			BIT(3)
151 #define GEN_PLD_W_EMPTY			BIT(2)
152 #define GEN_CMD_FULL			BIT(1)
153 #define GEN_CMD_EMPTY			BIT(0)
154 
155 #define DSI_TO_CNT_CFG			0x78
156 #define HSTX_TO_CNT(p)			(((p) & 0xffff) << 16)
157 #define LPRX_TO_CNT(p)			((p) & 0xffff)
158 
159 #define DSI_HS_RD_TO_CNT		0x7c
160 #define DSI_LP_RD_TO_CNT		0x80
161 #define DSI_HS_WR_TO_CNT		0x84
162 #define DSI_LP_WR_TO_CNT		0x88
163 #define DSI_BTA_TO_CNT			0x8c
164 
165 #define DSI_LPCLK_CTRL			0x94
166 #define AUTO_CLKLANE_CTRL		BIT(1)
167 #define PHY_TXREQUESTCLKHS		BIT(0)
168 
169 #define DSI_PHY_TMR_LPCLK_CFG		0x98
170 #define PHY_CLKHS2LP_TIME(lbcc)		(((lbcc) & 0x3ff) << 16)
171 #define PHY_CLKLP2HS_TIME(lbcc)		((lbcc) & 0x3ff)
172 
173 #define DSI_PHY_TMR_CFG			0x9c
174 #define PHY_HS2LP_TIME(lbcc)		(((lbcc) & 0xff) << 24)
175 #define PHY_LP2HS_TIME(lbcc)		(((lbcc) & 0xff) << 16)
176 #define MAX_RD_TIME(lbcc)		((lbcc) & 0x7fff)
177 #define PHY_HS2LP_TIME_V131(lbcc)	(((lbcc) & 0x3ff) << 16)
178 #define PHY_LP2HS_TIME_V131(lbcc)	((lbcc) & 0x3ff)
179 
180 #define DSI_PHY_RSTZ			0xa0
181 #define PHY_DISFORCEPLL			0
182 #define PHY_ENFORCEPLL			BIT(3)
183 #define PHY_DISABLECLK			0
184 #define PHY_ENABLECLK			BIT(2)
185 #define PHY_RSTZ			0
186 #define PHY_UNRSTZ			BIT(1)
187 #define PHY_SHUTDOWNZ			0
188 #define PHY_UNSHUTDOWNZ			BIT(0)
189 
190 #define DSI_PHY_IF_CFG			0xa4
191 #define PHY_STOP_WAIT_TIME(cycle)	(((cycle) & 0xff) << 8)
192 #define N_LANES(n)			(((n) - 1) & 0x3)
193 
194 #define DSI_PHY_ULPS_CTRL		0xa8
195 #define DSI_PHY_TX_TRIGGERS		0xac
196 
197 #define DSI_PHY_STATUS			0xb0
198 #define PHY_STOP_STATE_CLK_LANE		BIT(2)
199 #define PHY_LOCK			BIT(0)
200 
201 #define DSI_PHY_TST_CTRL0		0xb4
202 #define PHY_TESTCLK			BIT(1)
203 #define PHY_UNTESTCLK			0
204 #define PHY_TESTCLR			BIT(0)
205 #define PHY_UNTESTCLR			0
206 
207 #define DSI_PHY_TST_CTRL1		0xb8
208 #define PHY_TESTEN			BIT(16)
209 #define PHY_UNTESTEN			0
210 #define PHY_TESTDOUT(n)			(((n) & 0xff) << 8)
211 #define PHY_TESTDIN(n)			((n) & 0xff)
212 
213 #define DSI_INT_ST0			0xbc
214 #define DSI_INT_ST1			0xc0
215 #define DSI_INT_MSK0			0xc4
216 #define DSI_INT_MSK1			0xc8
217 
218 #define DSI_PHY_TMR_RD_CFG		0xf4
219 #define MAX_RD_TIME_V131(lbcc)		((lbcc) & 0x7fff)
220 
221 #define PHY_STATUS_TIMEOUT_US		10000
222 #define CMD_PKT_STATUS_TIMEOUT_US	20000
223 
224 struct dw_mipi_dsi {
225 	struct drm_bridge bridge;
226 	struct mipi_dsi_host dsi_host;
227 	struct drm_bridge *panel_bridge;
228 	struct device *dev;
229 	void __iomem *base;
230 
231 	struct clk *pclk;
232 
233 	unsigned int lane_mbps; /* per lane */
234 	u32 channel;
235 	u32 lanes;
236 	u32 format;
237 	unsigned long mode_flags;
238 
239 #ifdef CONFIG_DEBUG_FS
240 	struct dentry *debugfs;
241 
242 	bool vpg;
243 	bool vpg_horizontal;
244 #endif /* CONFIG_DEBUG_FS */
245 
246 	struct dw_mipi_dsi *master; /* dual-dsi master ptr */
247 	struct dw_mipi_dsi *slave; /* dual-dsi slave ptr */
248 
249 	const struct dw_mipi_dsi_plat_data *plat_data;
250 };
251 
252 /*
253  * Check if either a link to a master or slave is present
254  */
255 static inline bool dw_mipi_is_dual_mode(struct dw_mipi_dsi *dsi)
256 {
257 	return dsi->slave || dsi->master;
258 }
259 
260 /*
261  * The controller should generate 2 frames before
262  * preparing the peripheral.
263  */
264 static void dw_mipi_dsi_wait_for_two_frames(const struct drm_display_mode *mode)
265 {
266 	int refresh, two_frames;
267 
268 	refresh = drm_mode_vrefresh(mode);
269 	two_frames = DIV_ROUND_UP(MSEC_PER_SEC, refresh) * 2;
270 	msleep(two_frames);
271 }
272 
273 static inline struct dw_mipi_dsi *host_to_dsi(struct mipi_dsi_host *host)
274 {
275 	return container_of(host, struct dw_mipi_dsi, dsi_host);
276 }
277 
278 static inline struct dw_mipi_dsi *bridge_to_dsi(struct drm_bridge *bridge)
279 {
280 	return container_of(bridge, struct dw_mipi_dsi, bridge);
281 }
282 
283 static inline void dsi_write(struct dw_mipi_dsi *dsi, u32 reg, u32 val)
284 {
285 	writel(val, dsi->base + reg);
286 }
287 
288 static inline u32 dsi_read(struct dw_mipi_dsi *dsi, u32 reg)
289 {
290 	return readl(dsi->base + reg);
291 }
292 
293 static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host,
294 				   struct mipi_dsi_device *device)
295 {
296 	struct dw_mipi_dsi *dsi = host_to_dsi(host);
297 	const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
298 	struct drm_bridge *bridge;
299 	struct drm_panel *panel;
300 	int ret;
301 
302 	if (device->lanes > dsi->plat_data->max_data_lanes) {
303 		dev_err(dsi->dev, "the number of data lanes(%u) is too many\n",
304 			device->lanes);
305 		return -EINVAL;
306 	}
307 
308 	dsi->lanes = device->lanes;
309 	dsi->channel = device->channel;
310 	dsi->format = device->format;
311 	dsi->mode_flags = device->mode_flags;
312 
313 	ret = drm_of_find_panel_or_bridge(host->dev->of_node, 1, 0,
314 					  &panel, &bridge);
315 	if (ret)
316 		return ret;
317 
318 	if (panel) {
319 		bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DSI);
320 		if (IS_ERR(bridge))
321 			return PTR_ERR(bridge);
322 	}
323 
324 	dsi->panel_bridge = bridge;
325 
326 	drm_bridge_add(&dsi->bridge);
327 
328 	if (pdata->host_ops && pdata->host_ops->attach) {
329 		ret = pdata->host_ops->attach(pdata->priv_data, device);
330 		if (ret < 0)
331 			return ret;
332 	}
333 
334 	return 0;
335 }
336 
337 static int dw_mipi_dsi_host_detach(struct mipi_dsi_host *host,
338 				   struct mipi_dsi_device *device)
339 {
340 	struct dw_mipi_dsi *dsi = host_to_dsi(host);
341 	const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
342 	int ret;
343 
344 	if (pdata->host_ops && pdata->host_ops->detach) {
345 		ret = pdata->host_ops->detach(pdata->priv_data, device);
346 		if (ret < 0)
347 			return ret;
348 	}
349 
350 	drm_of_panel_bridge_remove(host->dev->of_node, 1, 0);
351 
352 	drm_bridge_remove(&dsi->bridge);
353 
354 	return 0;
355 }
356 
357 static void dw_mipi_message_config(struct dw_mipi_dsi *dsi,
358 				   const struct mipi_dsi_msg *msg)
359 {
360 	bool lpm = msg->flags & MIPI_DSI_MSG_USE_LPM;
361 	u32 val = 0;
362 
363 	if (msg->flags & MIPI_DSI_MSG_REQ_ACK)
364 		val |= ACK_RQST_EN;
365 	if (lpm)
366 		val |= CMD_MODE_ALL_LP;
367 
368 	dsi_write(dsi, DSI_LPCLK_CTRL, lpm ? 0 : PHY_TXREQUESTCLKHS);
369 	dsi_write(dsi, DSI_CMD_MODE_CFG, val);
370 }
371 
372 static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val)
373 {
374 	int ret;
375 	u32 val, mask;
376 
377 	ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
378 				 val, !(val & GEN_CMD_FULL), 1000,
379 				 CMD_PKT_STATUS_TIMEOUT_US);
380 	if (ret) {
381 		dev_err(dsi->dev, "failed to get available command FIFO\n");
382 		return ret;
383 	}
384 
385 	dsi_write(dsi, DSI_GEN_HDR, hdr_val);
386 
387 	mask = GEN_CMD_EMPTY | GEN_PLD_W_EMPTY;
388 	ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
389 				 val, (val & mask) == mask,
390 				 1000, CMD_PKT_STATUS_TIMEOUT_US);
391 	if (ret) {
392 		dev_err(dsi->dev, "failed to write command FIFO\n");
393 		return ret;
394 	}
395 
396 	return 0;
397 }
398 
399 static int dw_mipi_dsi_write(struct dw_mipi_dsi *dsi,
400 			     const struct mipi_dsi_packet *packet)
401 {
402 	const u8 *tx_buf = packet->payload;
403 	int len = packet->payload_length, pld_data_bytes = sizeof(u32), ret;
404 	__le32 word;
405 	u32 val;
406 
407 	while (len) {
408 		if (len < pld_data_bytes) {
409 			word = 0;
410 			memcpy(&word, tx_buf, len);
411 			dsi_write(dsi, DSI_GEN_PLD_DATA, le32_to_cpu(word));
412 			len = 0;
413 		} else {
414 			memcpy(&word, tx_buf, pld_data_bytes);
415 			dsi_write(dsi, DSI_GEN_PLD_DATA, le32_to_cpu(word));
416 			tx_buf += pld_data_bytes;
417 			len -= pld_data_bytes;
418 		}
419 
420 		ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
421 					 val, !(val & GEN_PLD_W_FULL), 1000,
422 					 CMD_PKT_STATUS_TIMEOUT_US);
423 		if (ret) {
424 			dev_err(dsi->dev,
425 				"failed to get available write payload FIFO\n");
426 			return ret;
427 		}
428 	}
429 
430 	word = 0;
431 	memcpy(&word, packet->header, sizeof(packet->header));
432 	return dw_mipi_dsi_gen_pkt_hdr_write(dsi, le32_to_cpu(word));
433 }
434 
435 static int dw_mipi_dsi_read(struct dw_mipi_dsi *dsi,
436 			    const struct mipi_dsi_msg *msg)
437 {
438 	int i, j, ret, len = msg->rx_len;
439 	u8 *buf = msg->rx_buf;
440 	u32 val;
441 
442 	/* Wait end of the read operation */
443 	ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
444 				 val, !(val & GEN_RD_CMD_BUSY),
445 				 1000, CMD_PKT_STATUS_TIMEOUT_US);
446 	if (ret) {
447 		dev_err(dsi->dev, "Timeout during read operation\n");
448 		return ret;
449 	}
450 
451 	for (i = 0; i < len; i += 4) {
452 		/* Read fifo must not be empty before all bytes are read */
453 		ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
454 					 val, !(val & GEN_PLD_R_EMPTY),
455 					 1000, CMD_PKT_STATUS_TIMEOUT_US);
456 		if (ret) {
457 			dev_err(dsi->dev, "Read payload FIFO is empty\n");
458 			return ret;
459 		}
460 
461 		val = dsi_read(dsi, DSI_GEN_PLD_DATA);
462 		for (j = 0; j < 4 && j + i < len; j++)
463 			buf[i + j] = val >> (8 * j);
464 	}
465 
466 	return ret;
467 }
468 
469 static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host,
470 					 const struct mipi_dsi_msg *msg)
471 {
472 	struct dw_mipi_dsi *dsi = host_to_dsi(host);
473 	struct mipi_dsi_packet packet;
474 	int ret, nb_bytes;
475 
476 	ret = mipi_dsi_create_packet(&packet, msg);
477 	if (ret) {
478 		dev_err(dsi->dev, "failed to create packet: %d\n", ret);
479 		return ret;
480 	}
481 
482 	dw_mipi_message_config(dsi, msg);
483 	if (dsi->slave)
484 		dw_mipi_message_config(dsi->slave, msg);
485 
486 	ret = dw_mipi_dsi_write(dsi, &packet);
487 	if (ret)
488 		return ret;
489 	if (dsi->slave) {
490 		ret = dw_mipi_dsi_write(dsi->slave, &packet);
491 		if (ret)
492 			return ret;
493 	}
494 
495 	if (msg->rx_buf && msg->rx_len) {
496 		ret = dw_mipi_dsi_read(dsi, msg);
497 		if (ret)
498 			return ret;
499 		nb_bytes = msg->rx_len;
500 	} else {
501 		nb_bytes = packet.size;
502 	}
503 
504 	return nb_bytes;
505 }
506 
507 static const struct mipi_dsi_host_ops dw_mipi_dsi_host_ops = {
508 	.attach = dw_mipi_dsi_host_attach,
509 	.detach = dw_mipi_dsi_host_detach,
510 	.transfer = dw_mipi_dsi_host_transfer,
511 };
512 
513 static void dw_mipi_dsi_video_mode_config(struct dw_mipi_dsi *dsi)
514 {
515 	u32 val;
516 
517 	/*
518 	 * TODO dw drv improvements
519 	 * enabling low power is panel-dependent, we should use the
520 	 * panel configuration here...
521 	 */
522 	val = ENABLE_LOW_POWER;
523 
524 	if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
525 		val |= VID_MODE_TYPE_BURST;
526 	else if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
527 		val |= VID_MODE_TYPE_NON_BURST_SYNC_PULSES;
528 	else
529 		val |= VID_MODE_TYPE_NON_BURST_SYNC_EVENTS;
530 
531 #ifdef CONFIG_DEBUG_FS
532 	if (dsi->vpg) {
533 		val |= VID_MODE_VPG_ENABLE;
534 		val |= dsi->vpg_horizontal ? VID_MODE_VPG_HORIZONTAL : 0;
535 	}
536 #endif /* CONFIG_DEBUG_FS */
537 
538 	dsi_write(dsi, DSI_VID_MODE_CFG, val);
539 }
540 
541 static void dw_mipi_dsi_set_mode(struct dw_mipi_dsi *dsi,
542 				 unsigned long mode_flags)
543 {
544 	dsi_write(dsi, DSI_PWR_UP, RESET);
545 
546 	if (mode_flags & MIPI_DSI_MODE_VIDEO) {
547 		dsi_write(dsi, DSI_MODE_CFG, ENABLE_VIDEO_MODE);
548 		dw_mipi_dsi_video_mode_config(dsi);
549 		dsi_write(dsi, DSI_LPCLK_CTRL, PHY_TXREQUESTCLKHS);
550 	} else {
551 		dsi_write(dsi, DSI_MODE_CFG, ENABLE_CMD_MODE);
552 	}
553 
554 	dsi_write(dsi, DSI_PWR_UP, POWERUP);
555 }
556 
557 static void dw_mipi_dsi_disable(struct dw_mipi_dsi *dsi)
558 {
559 	dsi_write(dsi, DSI_PWR_UP, RESET);
560 	dsi_write(dsi, DSI_PHY_RSTZ, PHY_RSTZ);
561 }
562 
563 static void dw_mipi_dsi_init(struct dw_mipi_dsi *dsi)
564 {
565 	/*
566 	 * The maximum permitted escape clock is 20MHz and it is derived from
567 	 * lanebyteclk, which is running at "lane_mbps / 8".  Thus we want:
568 	 *
569 	 *     (lane_mbps >> 3) / esc_clk_division < 20
570 	 * which is:
571 	 *     (lane_mbps >> 3) / 20 > esc_clk_division
572 	 */
573 	u32 esc_clk_division = (dsi->lane_mbps >> 3) / 20 + 1;
574 
575 	dsi_write(dsi, DSI_PWR_UP, RESET);
576 
577 	/*
578 	 * TODO dw drv improvements
579 	 * timeout clock division should be computed with the
580 	 * high speed transmission counter timeout and byte lane...
581 	 */
582 	dsi_write(dsi, DSI_CLKMGR_CFG, TO_CLK_DIVISION(10) |
583 		  TX_ESC_CLK_DIVISION(esc_clk_division));
584 }
585 
586 static void dw_mipi_dsi_dpi_config(struct dw_mipi_dsi *dsi,
587 				   const struct drm_display_mode *mode)
588 {
589 	u32 val = 0, color = 0;
590 
591 	switch (dsi->format) {
592 	case MIPI_DSI_FMT_RGB888:
593 		color = DPI_COLOR_CODING_24BIT;
594 		break;
595 	case MIPI_DSI_FMT_RGB666:
596 		color = DPI_COLOR_CODING_18BIT_2 | LOOSELY18_EN;
597 		break;
598 	case MIPI_DSI_FMT_RGB666_PACKED:
599 		color = DPI_COLOR_CODING_18BIT_1;
600 		break;
601 	case MIPI_DSI_FMT_RGB565:
602 		color = DPI_COLOR_CODING_16BIT_1;
603 		break;
604 	}
605 
606 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
607 		val |= VSYNC_ACTIVE_LOW;
608 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
609 		val |= HSYNC_ACTIVE_LOW;
610 
611 	dsi_write(dsi, DSI_DPI_VCID, DPI_VCID(dsi->channel));
612 	dsi_write(dsi, DSI_DPI_COLOR_CODING, color);
613 	dsi_write(dsi, DSI_DPI_CFG_POL, val);
614 	/*
615 	 * TODO dw drv improvements
616 	 * largest packet sizes during hfp or during vsa/vpb/vfp
617 	 * should be computed according to byte lane, lane number and only
618 	 * if sending lp cmds in high speed is enable (PHY_TXREQUESTCLKHS)
619 	 */
620 	dsi_write(dsi, DSI_DPI_LP_CMD_TIM, OUTVACT_LPCMD_TIME(4)
621 		  | INVACT_LPCMD_TIME(4));
622 }
623 
624 static void dw_mipi_dsi_packet_handler_config(struct dw_mipi_dsi *dsi)
625 {
626 	dsi_write(dsi, DSI_PCKHDL_CFG, CRC_RX_EN | ECC_RX_EN | BTA_EN);
627 }
628 
629 static void dw_mipi_dsi_video_packet_config(struct dw_mipi_dsi *dsi,
630 					    const struct drm_display_mode *mode)
631 {
632 	/*
633 	 * TODO dw drv improvements
634 	 * only burst mode is supported here. For non-burst video modes,
635 	 * we should compute DSI_VID_PKT_SIZE, DSI_VCCR.NUMC &
636 	 * DSI_VNPCR.NPSIZE... especially because this driver supports
637 	 * non-burst video modes, see dw_mipi_dsi_video_mode_config()...
638 	 */
639 
640 	dsi_write(dsi, DSI_VID_PKT_SIZE,
641 		       dw_mipi_is_dual_mode(dsi) ?
642 				VID_PKT_SIZE(mode->hdisplay / 2) :
643 				VID_PKT_SIZE(mode->hdisplay));
644 }
645 
646 static void dw_mipi_dsi_command_mode_config(struct dw_mipi_dsi *dsi)
647 {
648 	/*
649 	 * TODO dw drv improvements
650 	 * compute high speed transmission counter timeout according
651 	 * to the timeout clock division (TO_CLK_DIVISION) and byte lane...
652 	 */
653 	dsi_write(dsi, DSI_TO_CNT_CFG, HSTX_TO_CNT(1000) | LPRX_TO_CNT(1000));
654 	/*
655 	 * TODO dw drv improvements
656 	 * the Bus-Turn-Around Timeout Counter should be computed
657 	 * according to byte lane...
658 	 */
659 	dsi_write(dsi, DSI_BTA_TO_CNT, 0xd00);
660 	dsi_write(dsi, DSI_MODE_CFG, ENABLE_CMD_MODE);
661 }
662 
663 /* Get lane byte clock cycles. */
664 static u32 dw_mipi_dsi_get_hcomponent_lbcc(struct dw_mipi_dsi *dsi,
665 					   const struct drm_display_mode *mode,
666 					   u32 hcomponent)
667 {
668 	u32 frac, lbcc;
669 
670 	lbcc = hcomponent * dsi->lane_mbps * MSEC_PER_SEC / 8;
671 
672 	frac = lbcc % mode->clock;
673 	lbcc = lbcc / mode->clock;
674 	if (frac)
675 		lbcc++;
676 
677 	return lbcc;
678 }
679 
680 static void dw_mipi_dsi_line_timer_config(struct dw_mipi_dsi *dsi,
681 					  const struct drm_display_mode *mode)
682 {
683 	u32 htotal, hsa, hbp, lbcc;
684 
685 	htotal = mode->htotal;
686 	hsa = mode->hsync_end - mode->hsync_start;
687 	hbp = mode->htotal - mode->hsync_end;
688 
689 	/*
690 	 * TODO dw drv improvements
691 	 * computations below may be improved...
692 	 */
693 	lbcc = dw_mipi_dsi_get_hcomponent_lbcc(dsi, mode, htotal);
694 	dsi_write(dsi, DSI_VID_HLINE_TIME, lbcc);
695 
696 	lbcc = dw_mipi_dsi_get_hcomponent_lbcc(dsi, mode, hsa);
697 	dsi_write(dsi, DSI_VID_HSA_TIME, lbcc);
698 
699 	lbcc = dw_mipi_dsi_get_hcomponent_lbcc(dsi, mode, hbp);
700 	dsi_write(dsi, DSI_VID_HBP_TIME, lbcc);
701 }
702 
703 static void dw_mipi_dsi_vertical_timing_config(struct dw_mipi_dsi *dsi,
704 					const struct drm_display_mode *mode)
705 {
706 	u32 vactive, vsa, vfp, vbp;
707 
708 	vactive = mode->vdisplay;
709 	vsa = mode->vsync_end - mode->vsync_start;
710 	vfp = mode->vsync_start - mode->vdisplay;
711 	vbp = mode->vtotal - mode->vsync_end;
712 
713 	dsi_write(dsi, DSI_VID_VACTIVE_LINES, vactive);
714 	dsi_write(dsi, DSI_VID_VSA_LINES, vsa);
715 	dsi_write(dsi, DSI_VID_VFP_LINES, vfp);
716 	dsi_write(dsi, DSI_VID_VBP_LINES, vbp);
717 }
718 
719 static void dw_mipi_dsi_dphy_timing_config(struct dw_mipi_dsi *dsi)
720 {
721 	u32 hw_version;
722 
723 	/*
724 	 * TODO dw drv improvements
725 	 * data & clock lane timers should be computed according to panel
726 	 * blankings and to the automatic clock lane control mode...
727 	 * note: DSI_PHY_TMR_CFG.MAX_RD_TIME should be in line with
728 	 * DSI_CMD_MODE_CFG.MAX_RD_PKT_SIZE_LP (see CMD_MODE_ALL_LP)
729 	 */
730 
731 	hw_version = dsi_read(dsi, DSI_VERSION) & VERSION;
732 
733 	if (hw_version >= HWVER_131) {
734 		dsi_write(dsi, DSI_PHY_TMR_CFG, PHY_HS2LP_TIME_V131(0x40) |
735 			  PHY_LP2HS_TIME_V131(0x40));
736 		dsi_write(dsi, DSI_PHY_TMR_RD_CFG, MAX_RD_TIME_V131(10000));
737 	} else {
738 		dsi_write(dsi, DSI_PHY_TMR_CFG, PHY_HS2LP_TIME(0x40) |
739 			  PHY_LP2HS_TIME(0x40) | MAX_RD_TIME(10000));
740 	}
741 
742 	dsi_write(dsi, DSI_PHY_TMR_LPCLK_CFG, PHY_CLKHS2LP_TIME(0x40)
743 		  | PHY_CLKLP2HS_TIME(0x40));
744 }
745 
746 static void dw_mipi_dsi_dphy_interface_config(struct dw_mipi_dsi *dsi)
747 {
748 	/*
749 	 * TODO dw drv improvements
750 	 * stop wait time should be the maximum between host dsi
751 	 * and panel stop wait times
752 	 */
753 	dsi_write(dsi, DSI_PHY_IF_CFG, PHY_STOP_WAIT_TIME(0x20) |
754 		  N_LANES(dsi->lanes));
755 }
756 
757 static void dw_mipi_dsi_dphy_init(struct dw_mipi_dsi *dsi)
758 {
759 	/* Clear PHY state */
760 	dsi_write(dsi, DSI_PHY_RSTZ, PHY_DISFORCEPLL | PHY_DISABLECLK
761 		  | PHY_RSTZ | PHY_SHUTDOWNZ);
762 	dsi_write(dsi, DSI_PHY_TST_CTRL0, PHY_UNTESTCLR);
763 	dsi_write(dsi, DSI_PHY_TST_CTRL0, PHY_TESTCLR);
764 	dsi_write(dsi, DSI_PHY_TST_CTRL0, PHY_UNTESTCLR);
765 }
766 
767 static void dw_mipi_dsi_dphy_enable(struct dw_mipi_dsi *dsi)
768 {
769 	u32 val;
770 	int ret;
771 
772 	dsi_write(dsi, DSI_PHY_RSTZ, PHY_ENFORCEPLL | PHY_ENABLECLK |
773 		  PHY_UNRSTZ | PHY_UNSHUTDOWNZ);
774 
775 	ret = readl_poll_timeout(dsi->base + DSI_PHY_STATUS, val,
776 				 val & PHY_LOCK, 1000, PHY_STATUS_TIMEOUT_US);
777 	if (ret)
778 		DRM_DEBUG_DRIVER("failed to wait phy lock state\n");
779 
780 	ret = readl_poll_timeout(dsi->base + DSI_PHY_STATUS,
781 				 val, val & PHY_STOP_STATE_CLK_LANE, 1000,
782 				 PHY_STATUS_TIMEOUT_US);
783 	if (ret)
784 		DRM_DEBUG_DRIVER("failed to wait phy clk lane stop state\n");
785 }
786 
787 static void dw_mipi_dsi_clear_err(struct dw_mipi_dsi *dsi)
788 {
789 	dsi_read(dsi, DSI_INT_ST0);
790 	dsi_read(dsi, DSI_INT_ST1);
791 	dsi_write(dsi, DSI_INT_MSK0, 0);
792 	dsi_write(dsi, DSI_INT_MSK1, 0);
793 }
794 
795 static void dw_mipi_dsi_bridge_post_disable(struct drm_bridge *bridge)
796 {
797 	struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
798 	const struct dw_mipi_dsi_phy_ops *phy_ops = dsi->plat_data->phy_ops;
799 
800 	if (phy_ops->power_off)
801 		phy_ops->power_off(dsi->plat_data->priv_data);
802 
803 	/*
804 	 * Switch to command mode before panel-bridge post_disable &
805 	 * panel unprepare.
806 	 * Note: panel-bridge disable & panel disable has been called
807 	 * before by the drm framework.
808 	 */
809 	dw_mipi_dsi_set_mode(dsi, 0);
810 
811 	/*
812 	 * TODO Only way found to call panel-bridge post_disable &
813 	 * panel unprepare before the dsi "final" disable...
814 	 * This needs to be fixed in the drm_bridge framework and the API
815 	 * needs to be updated to manage our own call chains...
816 	 */
817 	dsi->panel_bridge->funcs->post_disable(dsi->panel_bridge);
818 
819 	if (dsi->slave) {
820 		dw_mipi_dsi_disable(dsi->slave);
821 		clk_disable_unprepare(dsi->slave->pclk);
822 		pm_runtime_put(dsi->slave->dev);
823 	}
824 	dw_mipi_dsi_disable(dsi);
825 
826 	clk_disable_unprepare(dsi->pclk);
827 	pm_runtime_put(dsi->dev);
828 }
829 
830 static unsigned int dw_mipi_dsi_get_lanes(struct dw_mipi_dsi *dsi)
831 {
832 	/* this instance is the slave, so add the master's lanes */
833 	if (dsi->master)
834 		return dsi->master->lanes + dsi->lanes;
835 
836 	/* this instance is the master, so add the slave's lanes */
837 	if (dsi->slave)
838 		return dsi->lanes + dsi->slave->lanes;
839 
840 	/* single-dsi, so no other instance to consider */
841 	return dsi->lanes;
842 }
843 
844 static void dw_mipi_dsi_mode_set(struct dw_mipi_dsi *dsi,
845 				 const struct drm_display_mode *adjusted_mode)
846 {
847 	const struct dw_mipi_dsi_phy_ops *phy_ops = dsi->plat_data->phy_ops;
848 	void *priv_data = dsi->plat_data->priv_data;
849 	int ret;
850 	u32 lanes = dw_mipi_dsi_get_lanes(dsi);
851 
852 	clk_prepare_enable(dsi->pclk);
853 
854 	ret = phy_ops->get_lane_mbps(priv_data, adjusted_mode, dsi->mode_flags,
855 				     lanes, dsi->format, &dsi->lane_mbps);
856 	if (ret)
857 		DRM_DEBUG_DRIVER("Phy get_lane_mbps() failed\n");
858 
859 	pm_runtime_get_sync(dsi->dev);
860 	dw_mipi_dsi_init(dsi);
861 	dw_mipi_dsi_dpi_config(dsi, adjusted_mode);
862 	dw_mipi_dsi_packet_handler_config(dsi);
863 	dw_mipi_dsi_video_mode_config(dsi);
864 	dw_mipi_dsi_video_packet_config(dsi, adjusted_mode);
865 	dw_mipi_dsi_command_mode_config(dsi);
866 	dw_mipi_dsi_line_timer_config(dsi, adjusted_mode);
867 	dw_mipi_dsi_vertical_timing_config(dsi, adjusted_mode);
868 
869 	dw_mipi_dsi_dphy_init(dsi);
870 	dw_mipi_dsi_dphy_timing_config(dsi);
871 	dw_mipi_dsi_dphy_interface_config(dsi);
872 
873 	dw_mipi_dsi_clear_err(dsi);
874 
875 	ret = phy_ops->init(priv_data);
876 	if (ret)
877 		DRM_DEBUG_DRIVER("Phy init() failed\n");
878 
879 	dw_mipi_dsi_dphy_enable(dsi);
880 
881 	dw_mipi_dsi_wait_for_two_frames(adjusted_mode);
882 
883 	/* Switch to cmd mode for panel-bridge pre_enable & panel prepare */
884 	dw_mipi_dsi_set_mode(dsi, 0);
885 }
886 
887 static void dw_mipi_dsi_bridge_mode_set(struct drm_bridge *bridge,
888 					const struct drm_display_mode *mode,
889 					const struct drm_display_mode *adjusted_mode)
890 {
891 	struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
892 
893 	dw_mipi_dsi_mode_set(dsi, adjusted_mode);
894 	if (dsi->slave)
895 		dw_mipi_dsi_mode_set(dsi->slave, adjusted_mode);
896 }
897 
898 static void dw_mipi_dsi_bridge_enable(struct drm_bridge *bridge)
899 {
900 	struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
901 	const struct dw_mipi_dsi_phy_ops *phy_ops = dsi->plat_data->phy_ops;
902 
903 	/* Switch to video mode for panel-bridge enable & panel enable */
904 	dw_mipi_dsi_set_mode(dsi, MIPI_DSI_MODE_VIDEO);
905 	if (dsi->slave)
906 		dw_mipi_dsi_set_mode(dsi->slave, MIPI_DSI_MODE_VIDEO);
907 
908 	if (phy_ops->power_on)
909 		phy_ops->power_on(dsi->plat_data->priv_data);
910 }
911 
912 static enum drm_mode_status
913 dw_mipi_dsi_bridge_mode_valid(struct drm_bridge *bridge,
914 			      const struct drm_display_mode *mode)
915 {
916 	struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
917 	const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
918 	enum drm_mode_status mode_status = MODE_OK;
919 
920 	if (pdata->mode_valid)
921 		mode_status = pdata->mode_valid(pdata->priv_data, mode);
922 
923 	return mode_status;
924 }
925 
926 static int dw_mipi_dsi_bridge_attach(struct drm_bridge *bridge)
927 {
928 	struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
929 
930 	if (!bridge->encoder) {
931 		DRM_ERROR("Parent encoder object not found\n");
932 		return -ENODEV;
933 	}
934 
935 	/* Set the encoder type as caller does not know it */
936 	bridge->encoder->encoder_type = DRM_MODE_ENCODER_DSI;
937 
938 	/* Attach the panel-bridge to the dsi bridge */
939 	return drm_bridge_attach(bridge->encoder, dsi->panel_bridge, bridge);
940 }
941 
942 static const struct drm_bridge_funcs dw_mipi_dsi_bridge_funcs = {
943 	.mode_set     = dw_mipi_dsi_bridge_mode_set,
944 	.enable	      = dw_mipi_dsi_bridge_enable,
945 	.post_disable = dw_mipi_dsi_bridge_post_disable,
946 	.mode_valid   = dw_mipi_dsi_bridge_mode_valid,
947 	.attach	      = dw_mipi_dsi_bridge_attach,
948 };
949 
950 #ifdef CONFIG_DEBUG_FS
951 
952 static void dw_mipi_dsi_debugfs_init(struct dw_mipi_dsi *dsi)
953 {
954 	dsi->debugfs = debugfs_create_dir(dev_name(dsi->dev), NULL);
955 	if (IS_ERR(dsi->debugfs)) {
956 		dev_err(dsi->dev, "failed to create debugfs root\n");
957 		return;
958 	}
959 
960 	debugfs_create_bool("vpg", 0660, dsi->debugfs, &dsi->vpg);
961 	debugfs_create_bool("vpg_horizontal", 0660, dsi->debugfs,
962 			    &dsi->vpg_horizontal);
963 }
964 
965 static void dw_mipi_dsi_debugfs_remove(struct dw_mipi_dsi *dsi)
966 {
967 	debugfs_remove_recursive(dsi->debugfs);
968 }
969 
970 #else
971 
972 static void dw_mipi_dsi_debugfs_init(struct dw_mipi_dsi *dsi) { }
973 static void dw_mipi_dsi_debugfs_remove(struct dw_mipi_dsi *dsi) { }
974 
975 #endif /* CONFIG_DEBUG_FS */
976 
977 static struct dw_mipi_dsi *
978 __dw_mipi_dsi_probe(struct platform_device *pdev,
979 		    const struct dw_mipi_dsi_plat_data *plat_data)
980 {
981 	struct device *dev = &pdev->dev;
982 	struct reset_control *apb_rst;
983 	struct dw_mipi_dsi *dsi;
984 	struct resource *res;
985 	int ret;
986 
987 	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
988 	if (!dsi)
989 		return ERR_PTR(-ENOMEM);
990 
991 	dsi->dev = dev;
992 	dsi->plat_data = plat_data;
993 
994 	if (!plat_data->phy_ops->init || !plat_data->phy_ops->get_lane_mbps) {
995 		DRM_ERROR("Phy not properly configured\n");
996 		return ERR_PTR(-ENODEV);
997 	}
998 
999 	if (!plat_data->base) {
1000 		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1001 		if (!res)
1002 			return ERR_PTR(-ENODEV);
1003 
1004 		dsi->base = devm_ioremap_resource(dev, res);
1005 		if (IS_ERR(dsi->base))
1006 			return ERR_PTR(-ENODEV);
1007 
1008 	} else {
1009 		dsi->base = plat_data->base;
1010 	}
1011 
1012 	dsi->pclk = devm_clk_get(dev, "pclk");
1013 	if (IS_ERR(dsi->pclk)) {
1014 		ret = PTR_ERR(dsi->pclk);
1015 		dev_err(dev, "Unable to get pclk: %d\n", ret);
1016 		return ERR_PTR(ret);
1017 	}
1018 
1019 	/*
1020 	 * Note that the reset was not defined in the initial device tree, so
1021 	 * we have to be prepared for it not being found.
1022 	 */
1023 	apb_rst = devm_reset_control_get_optional_exclusive(dev, "apb");
1024 	if (IS_ERR(apb_rst)) {
1025 		ret = PTR_ERR(apb_rst);
1026 
1027 		if (ret != -EPROBE_DEFER)
1028 			dev_err(dev, "Unable to get reset control: %d\n", ret);
1029 
1030 		return ERR_PTR(ret);
1031 	}
1032 
1033 	if (apb_rst) {
1034 		ret = clk_prepare_enable(dsi->pclk);
1035 		if (ret) {
1036 			dev_err(dev, "%s: Failed to enable pclk\n", __func__);
1037 			return ERR_PTR(ret);
1038 		}
1039 
1040 		reset_control_assert(apb_rst);
1041 		usleep_range(10, 20);
1042 		reset_control_deassert(apb_rst);
1043 
1044 		clk_disable_unprepare(dsi->pclk);
1045 	}
1046 
1047 	dw_mipi_dsi_debugfs_init(dsi);
1048 	pm_runtime_enable(dev);
1049 
1050 	dsi->dsi_host.ops = &dw_mipi_dsi_host_ops;
1051 	dsi->dsi_host.dev = dev;
1052 	ret = mipi_dsi_host_register(&dsi->dsi_host);
1053 	if (ret) {
1054 		dev_err(dev, "Failed to register MIPI host: %d\n", ret);
1055 		dw_mipi_dsi_debugfs_remove(dsi);
1056 		return ERR_PTR(ret);
1057 	}
1058 
1059 	dsi->bridge.driver_private = dsi;
1060 	dsi->bridge.funcs = &dw_mipi_dsi_bridge_funcs;
1061 #ifdef CONFIG_OF
1062 	dsi->bridge.of_node = pdev->dev.of_node;
1063 #endif
1064 
1065 	return dsi;
1066 }
1067 
1068 static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
1069 {
1070 	mipi_dsi_host_unregister(&dsi->dsi_host);
1071 
1072 	pm_runtime_disable(dsi->dev);
1073 	dw_mipi_dsi_debugfs_remove(dsi);
1074 }
1075 
1076 void dw_mipi_dsi_set_slave(struct dw_mipi_dsi *dsi, struct dw_mipi_dsi *slave)
1077 {
1078 	/* introduce controllers to each other */
1079 	dsi->slave = slave;
1080 	dsi->slave->master = dsi;
1081 
1082 	/* migrate settings for already attached displays */
1083 	dsi->slave->lanes = dsi->lanes;
1084 	dsi->slave->channel = dsi->channel;
1085 	dsi->slave->format = dsi->format;
1086 	dsi->slave->mode_flags = dsi->mode_flags;
1087 }
1088 EXPORT_SYMBOL_GPL(dw_mipi_dsi_set_slave);
1089 
1090 /*
1091  * Probe/remove API, used from platforms based on the DRM bridge API.
1092  */
1093 struct dw_mipi_dsi *
1094 dw_mipi_dsi_probe(struct platform_device *pdev,
1095 		  const struct dw_mipi_dsi_plat_data *plat_data)
1096 {
1097 	return __dw_mipi_dsi_probe(pdev, plat_data);
1098 }
1099 EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
1100 
1101 void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
1102 {
1103 	__dw_mipi_dsi_remove(dsi);
1104 }
1105 EXPORT_SYMBOL_GPL(dw_mipi_dsi_remove);
1106 
1107 /*
1108  * Bind/unbind API, used from platforms based on the component framework.
1109  */
1110 int dw_mipi_dsi_bind(struct dw_mipi_dsi *dsi, struct drm_encoder *encoder)
1111 {
1112 	int ret;
1113 
1114 	ret = drm_bridge_attach(encoder, &dsi->bridge, NULL);
1115 	if (ret) {
1116 		DRM_ERROR("Failed to initialize bridge with drm\n");
1117 		return ret;
1118 	}
1119 
1120 	return ret;
1121 }
1122 EXPORT_SYMBOL_GPL(dw_mipi_dsi_bind);
1123 
1124 void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi)
1125 {
1126 }
1127 EXPORT_SYMBOL_GPL(dw_mipi_dsi_unbind);
1128 
1129 MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
1130 MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
1131 MODULE_DESCRIPTION("DW MIPI DSI host controller driver");
1132 MODULE_LICENSE("GPL");
1133 MODULE_ALIAS("platform:dw-mipi-dsi");
1134