xref: /linux/drivers/gpu/drm/bridge/ssd2825.c (revision 44343e8b250abb2f6bfd615493ca07a7f11f3cc2)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <linux/clk.h>
4 #include <linux/delay.h>
5 #include <linux/device.h>
6 #include <linux/err.h>
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/mod_devicetable.h>
10 #include <linux/mutex.h>
11 #include <linux/of.h>
12 #include <linux/regulator/consumer.h>
13 #include <linux/spi/spi.h>
14 #include <linux/units.h>
15 
16 #include <drm/drm_atomic_helper.h>
17 #include <drm/drm_bridge.h>
18 #include <drm/drm_drv.h>
19 #include <drm/drm_mipi_dsi.h>
20 #include <drm/drm_of.h>
21 #include <drm/drm_panel.h>
22 #include <video/mipi_display.h>
23 
24 #define SSD2825_DEVICE_ID_REG			0xb0
25 #define SSD2825_RGB_INTERFACE_CTRL_REG_1	0xb1
26 #define SSD2825_RGB_INTERFACE_CTRL_REG_2	0xb2
27 #define SSD2825_RGB_INTERFACE_CTRL_REG_3	0xb3
28 #define SSD2825_RGB_INTERFACE_CTRL_REG_4	0xb4
29 #define SSD2825_RGB_INTERFACE_CTRL_REG_5	0xb5
30 #define SSD2825_RGB_INTERFACE_CTRL_REG_6	0xb6
31 #define   SSD2825_NON_BURST_EV			BIT(2)
32 #define   SSD2825_BURST				BIT(3)
33 #define   SSD2825_PCKL_HIGH			BIT(13)
34 #define   SSD2825_HSYNC_HIGH			BIT(14)
35 #define   SSD2825_VSYNC_HIGH			BIT(15)
36 #define SSD2825_CONFIGURATION_REG		0xb7
37 #define   SSD2825_CONF_REG_HS			BIT(0)
38 #define   SSD2825_CONF_REG_CKE			BIT(1)
39 #define   SSD2825_CONF_REG_SLP			BIT(2)
40 #define   SSD2825_CONF_REG_VEN			BIT(3)
41 #define   SSD2825_CONF_REG_HCLK			BIT(4)
42 #define   SSD2825_CONF_REG_CSS			BIT(5)
43 #define   SSD2825_CONF_REG_DCS			BIT(6)
44 #define   SSD2825_CONF_REG_REN			BIT(7)
45 #define   SSD2825_CONF_REG_ECD			BIT(8)
46 #define   SSD2825_CONF_REG_EOT			BIT(9)
47 #define   SSD2825_CONF_REG_LPE			BIT(10)
48 #define SSD2825_VC_CTRL_REG			0xb8
49 #define SSD2825_PLL_CTRL_REG			0xb9
50 #define SSD2825_PLL_CONFIGURATION_REG		0xba
51 #define SSD2825_CLOCK_CTRL_REG			0xbb
52 #define SSD2825_PACKET_SIZE_CTRL_REG_1		0xbc
53 #define SSD2825_PACKET_SIZE_CTRL_REG_2		0xbd
54 #define SSD2825_PACKET_SIZE_CTRL_REG_3		0xbe
55 #define SSD2825_PACKET_DROP_REG			0xbf
56 #define SSD2825_OPERATION_CTRL_REG		0xc0
57 #define SSD2825_MAX_RETURN_SIZE_REG		0xc1
58 #define SSD2825_RETURN_DATA_COUNT_REG		0xc2
59 #define SSD2825_ACK_RESPONSE_REG		0xc3
60 #define SSD2825_LINE_CTRL_REG			0xc4
61 #define SSD2825_INTERRUPT_CTRL_REG		0xc5
62 #define SSD2825_INTERRUPT_STATUS_REG		0xc6
63 #define SSD2825_ERROR_STATUS_REG		0xc7
64 #define SSD2825_DATA_FORMAT_REG			0xc8
65 #define SSD2825_DELAY_ADJ_REG_1			0xc9
66 #define SSD2825_DELAY_ADJ_REG_2			0xca
67 #define SSD2825_DELAY_ADJ_REG_3			0xcb
68 #define SSD2825_DELAY_ADJ_REG_4			0xcc
69 #define SSD2825_DELAY_ADJ_REG_5			0xcd
70 #define SSD2825_DELAY_ADJ_REG_6			0xce
71 #define SSD2825_HS_TX_TIMER_REG_1		0xcf
72 #define SSD2825_HS_TX_TIMER_REG_2		0xd0
73 #define SSD2825_LP_RX_TIMER_REG_1		0xd1
74 #define SSD2825_LP_RX_TIMER_REG_2		0xd2
75 #define SSD2825_TE_STATUS_REG			0xd3
76 #define SSD2825_SPI_READ_REG			0xd4
77 #define   SSD2825_SPI_READ_REG_RESET		0xfa
78 #define SSD2825_PLL_LOCK_REG			0xd5
79 #define SSD2825_TEST_REG			0xd6
80 #define SSD2825_TE_COUNT_REG			0xd7
81 #define SSD2825_ANALOG_CTRL_REG_1		0xd8
82 #define SSD2825_ANALOG_CTRL_REG_2		0xd9
83 #define SSD2825_ANALOG_CTRL_REG_3		0xda
84 #define SSD2825_ANALOG_CTRL_REG_4		0xdb
85 #define SSD2825_INTERRUPT_OUT_CTRL_REG		0xdc
86 #define SSD2825_RGB_INTERFACE_CTRL_REG_7	0xdd
87 #define SSD2825_LANE_CONFIGURATION_REG		0xde
88 #define SSD2825_DELAY_ADJ_REG_7			0xdf
89 #define SSD2825_INPUT_PIN_CTRL_REG_1		0xe0
90 #define SSD2825_INPUT_PIN_CTRL_REG_2		0xe1
91 #define SSD2825_BIDIR_PIN_CTRL_REG_1		0xe2
92 #define SSD2825_BIDIR_PIN_CTRL_REG_2		0xe3
93 #define SSD2825_BIDIR_PIN_CTRL_REG_3		0xe4
94 #define SSD2825_BIDIR_PIN_CTRL_REG_4		0xe5
95 #define SSD2825_BIDIR_PIN_CTRL_REG_5		0xe6
96 #define SSD2825_BIDIR_PIN_CTRL_REG_6		0xe7
97 #define SSD2825_BIDIR_PIN_CTRL_REG_7		0xe8
98 #define SSD2825_CABC_BRIGHTNESS_CTRL_REG_1	0xe9
99 #define SSD2825_CABC_BRIGHTNESS_CTRL_REG_2	0xea
100 #define SSD2825_CABC_BRIGHTNESS_STATUS_REG	0xeb
101 #define SSD2825_READ_REG			0xff
102 
103 #define SSD2825_COM_BYTE			0x00
104 #define SSD2825_DAT_BYTE			0x01
105 
106 #define SSD2828_LP_CLOCK_DIVIDER(n)		(((n) - 1) & 0x3f)
107 #define SSD2825_LP_MIN_CLK			5000 /* KHz */
108 #define SSD2825_REF_MIN_CLK			2000 /* KHz */
109 
110 static const struct regulator_bulk_data ssd2825_supplies[] = {
111 	{ .supply = "dvdd" },
112 	{ .supply = "avdd" },
113 	{ .supply = "vddio" },
114 };
115 
116 struct ssd2825_dsi_output {
117 	struct mipi_dsi_device *dev;
118 	struct drm_panel *panel;
119 	struct drm_bridge *bridge;
120 };
121 
122 struct ssd2825_priv {
123 	struct spi_device *spi;
124 	struct device *dev;
125 
126 	struct gpio_desc *reset_gpio;
127 	struct regulator_bulk_data *supplies;
128 
129 	struct clk *tx_clk;
130 
131 	struct mipi_dsi_host dsi_host;
132 	struct drm_bridge bridge;
133 	struct ssd2825_dsi_output output;
134 
135 	struct mutex mlock;	/* for host transfer operations */
136 
137 	u32 pd_lines;		/* number of Parallel Port Input Data Lines */
138 	u32 dsi_lanes;		/* number of DSI Lanes */
139 
140 	/* Parameters for PLL programming */
141 	u32 pll_freq_kbps;	/* PLL in kbps */
142 	u32 nibble_freq_khz;	/* PLL div by 4 */
143 
144 	u32 hzd;		/* HS Zero Delay in ns*/
145 	u32 hpd;		/* HS Prepare Delay is ns */
146 };
147 
148 static inline struct ssd2825_priv *dsi_host_to_ssd2825(struct mipi_dsi_host *host)
149 {
150 	return container_of(host, struct ssd2825_priv, dsi_host);
151 }
152 
153 static inline struct ssd2825_priv *bridge_to_ssd2825(struct drm_bridge *bridge)
154 {
155 	return container_of(bridge, struct ssd2825_priv, bridge);
156 }
157 
158 static int ssd2825_write_raw(struct ssd2825_priv *priv, u8 high_byte, u8 low_byte)
159 {
160 	struct spi_device *spi = priv->spi;
161 	u8 tx_buf[2];
162 
163 	/*
164 	 * Low byte is the value, high byte defines type of
165 	 * write cycle, 0 for command and 1 for data.
166 	 */
167 	tx_buf[0] = low_byte;
168 	tx_buf[1] = high_byte;
169 
170 	return spi_write(spi, tx_buf, 2);
171 }
172 
173 static int ssd2825_write_reg(struct ssd2825_priv *priv, u8 reg, u16 command)
174 {
175 	u8 datal = (command & 0x00FF);
176 	u8 datah = (command & 0xFF00) >> 8;
177 	int ret;
178 
179 	/* Command write cycle */
180 	ret = ssd2825_write_raw(priv, SSD2825_COM_BYTE, reg);
181 	if (ret)
182 		return ret;
183 
184 	/* Data write cycle bits 7-0 */
185 	ret = ssd2825_write_raw(priv, SSD2825_DAT_BYTE, datal);
186 	if (ret)
187 		return ret;
188 
189 	/* Data write cycle bits 15-8 */
190 	ret = ssd2825_write_raw(priv, SSD2825_DAT_BYTE, datah);
191 	if (ret)
192 		return ret;
193 
194 	return 0;
195 }
196 
197 static int ssd2825_write_dsi(struct ssd2825_priv *priv, const u8 *command, int len)
198 {
199 	int ret, i;
200 
201 	ret = ssd2825_write_reg(priv, SSD2825_PACKET_SIZE_CTRL_REG_1, len);
202 	if (ret)
203 		return ret;
204 
205 	ret = ssd2825_write_raw(priv, SSD2825_COM_BYTE, SSD2825_PACKET_DROP_REG);
206 	if (ret)
207 		return ret;
208 
209 	for (i = 0; i < len; i++) {
210 		ret = ssd2825_write_raw(priv, SSD2825_DAT_BYTE, command[i]);
211 		if (ret)
212 			return ret;
213 	}
214 
215 	return 0;
216 }
217 
218 static int ssd2825_read_raw(struct ssd2825_priv *priv, u8 cmd, u16 *data)
219 {
220 	struct spi_device *spi = priv->spi;
221 	struct spi_message msg;
222 	struct spi_transfer xfer[2];
223 	u8 tx_buf[2];
224 	u8 rx_buf[2];
225 	int ret;
226 
227 	memset(&xfer, 0, sizeof(xfer));
228 
229 	tx_buf[1] = (cmd & 0xFF00) >> 8;
230 	tx_buf[0] = (cmd & 0x00FF);
231 
232 	xfer[0].tx_buf = tx_buf;
233 	xfer[0].bits_per_word = 9;
234 	xfer[0].len = 2;
235 
236 	xfer[1].rx_buf = rx_buf;
237 	xfer[1].bits_per_word = 16;
238 	xfer[1].len = 2;
239 
240 	spi_message_init(&msg);
241 	spi_message_add_tail(&xfer[0], &msg);
242 	spi_message_add_tail(&xfer[1], &msg);
243 
244 	ret = spi_sync(spi, &msg);
245 	if (ret) {
246 		dev_err(&spi->dev, "ssd2825 read raw failed %d\n", ret);
247 		return ret;
248 	}
249 
250 	*data = rx_buf[1] | (rx_buf[0] << 8);
251 
252 	return 0;
253 }
254 
255 static int ssd2825_read_reg(struct ssd2825_priv *priv, u8 reg, u16 *data)
256 {
257 	int ret;
258 
259 	/* Reset the read register */
260 	ret = ssd2825_write_reg(priv, SSD2825_SPI_READ_REG, SSD2825_SPI_READ_REG_RESET);
261 	if (ret)
262 		return ret;
263 
264 	/* Push the address to read */
265 	ret = ssd2825_write_raw(priv, SSD2825_COM_BYTE, reg);
266 	if (ret)
267 		return ret;
268 
269 	/* Perform a reading cycle */
270 	ret = ssd2825_read_raw(priv, SSD2825_SPI_READ_REG_RESET, data);
271 	if (ret)
272 		return ret;
273 
274 	return 0;
275 }
276 
277 static int ssd2825_dsi_host_attach(struct mipi_dsi_host *host, struct mipi_dsi_device *dev)
278 {
279 	struct ssd2825_priv *priv = dsi_host_to_ssd2825(host);
280 	struct drm_bridge *bridge;
281 	struct drm_panel *panel;
282 	struct device_node *ep;
283 	int ret;
284 
285 	if (dev->lanes > 4) {
286 		dev_err(priv->dev, "unsupported number of data lanes(%u)\n", dev->lanes);
287 		return -EINVAL;
288 	}
289 
290 	/*
291 	 * ssd2825 supports both Video and Pulse mode, but the driver only
292 	 * implements Video (event) mode currently
293 	 */
294 	if (!(dev->mode_flags & MIPI_DSI_MODE_VIDEO)) {
295 		dev_err(priv->dev, "Only MIPI_DSI_MODE_VIDEO is supported\n");
296 		return -EOPNOTSUPP;
297 	}
298 
299 	ret = drm_of_find_panel_or_bridge(host->dev->of_node, 1, 0, &panel, &bridge);
300 	if (ret)
301 		return ret;
302 
303 	if (panel) {
304 		bridge = drm_panel_bridge_add_typed(panel, DRM_MODE_CONNECTOR_DSI);
305 		if (IS_ERR(bridge))
306 			return PTR_ERR(bridge);
307 	}
308 
309 	priv->output.dev = dev;
310 	priv->output.bridge = bridge;
311 	priv->output.panel = panel;
312 
313 	priv->dsi_lanes = dev->lanes;
314 
315 	/* get input ep (port0/endpoint0) */
316 	ret = -EINVAL;
317 	ep = of_graph_get_endpoint_by_regs(host->dev->of_node, 0, 0);
318 	if (ep) {
319 		ret = of_property_read_u32(ep, "bus-width", &priv->pd_lines);
320 		of_node_put(ep);
321 	}
322 
323 	if (ret)
324 		priv->pd_lines = mipi_dsi_pixel_format_to_bpp(dev->format);
325 
326 	drm_bridge_add(&priv->bridge);
327 
328 	return 0;
329 }
330 
331 static int ssd2825_dsi_host_detach(struct mipi_dsi_host *host, struct mipi_dsi_device *dev)
332 {
333 	struct ssd2825_priv *priv = dsi_host_to_ssd2825(host);
334 
335 	drm_bridge_remove(&priv->bridge);
336 	if (priv->output.panel)
337 		drm_panel_bridge_remove(priv->output.bridge);
338 
339 	return 0;
340 }
341 
342 static ssize_t ssd2825_dsi_host_transfer(struct mipi_dsi_host *host,
343 					 const struct mipi_dsi_msg *msg)
344 {
345 	struct ssd2825_priv *priv = dsi_host_to_ssd2825(host);
346 	u16 config;
347 	int ret;
348 
349 	if (msg->rx_len) {
350 		dev_warn(priv->dev, "MIPI rx is not supported\n");
351 		return -EOPNOTSUPP;
352 	}
353 
354 	guard(mutex)(&priv->mlock);
355 
356 	ret = ssd2825_read_reg(priv, SSD2825_CONFIGURATION_REG, &config);
357 	if (ret)
358 		return ret;
359 
360 	switch (msg->type) {
361 	case MIPI_DSI_DCS_SHORT_WRITE:
362 	case MIPI_DSI_DCS_SHORT_WRITE_PARAM:
363 	case MIPI_DSI_DCS_LONG_WRITE:
364 		config |= SSD2825_CONF_REG_DCS;
365 		break;
366 	case MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM:
367 	case MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM:
368 	case MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM:
369 	case MIPI_DSI_GENERIC_LONG_WRITE:
370 		config &= ~SSD2825_CONF_REG_DCS;
371 		break;
372 	case MIPI_DSI_DCS_READ:
373 	case MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM:
374 	case MIPI_DSI_GENERIC_READ_REQUEST_1_PARAM:
375 	case MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM:
376 	default:
377 		return 0;
378 	}
379 
380 	ret = ssd2825_write_reg(priv, SSD2825_CONFIGURATION_REG, config);
381 	if (ret)
382 		return ret;
383 
384 	ret = ssd2825_write_reg(priv, SSD2825_VC_CTRL_REG, 0x0000);
385 	if (ret)
386 		return ret;
387 
388 	ret = ssd2825_write_dsi(priv, msg->tx_buf, msg->tx_len);
389 	if (ret)
390 		return ret;
391 
392 	return 0;
393 }
394 
395 static const struct mipi_dsi_host_ops ssd2825_dsi_host_ops = {
396 	.attach = ssd2825_dsi_host_attach,
397 	.detach = ssd2825_dsi_host_detach,
398 	.transfer = ssd2825_dsi_host_transfer,
399 };
400 
401 static void ssd2825_hw_reset(struct ssd2825_priv *priv)
402 {
403 	gpiod_set_value_cansleep(priv->reset_gpio, 1);
404 	usleep_range(5000, 6000);
405 	gpiod_set_value_cansleep(priv->reset_gpio, 0);
406 	usleep_range(5000, 6000);
407 }
408 
409 /*
410  * PLL configuration register settings.
411  *
412  * See the "PLL Configuration Register Description" in the SSD2825 datasheet.
413  */
414 static u16 construct_pll_config(struct ssd2825_priv *priv,
415 				u32 desired_pll_freq_kbps, u32 reference_freq_khz)
416 {
417 	u32 div_factor = 1, mul_factor, fr = 0;
418 
419 	while (reference_freq_khz / (div_factor + 1) >= SSD2825_REF_MIN_CLK)
420 		div_factor++;
421 	if (div_factor > 31)
422 		div_factor = 31;
423 
424 	mul_factor = DIV_ROUND_UP(desired_pll_freq_kbps * div_factor,
425 				  reference_freq_khz);
426 
427 	priv->pll_freq_kbps = reference_freq_khz * mul_factor / div_factor;
428 	priv->nibble_freq_khz = priv->pll_freq_kbps / 4;
429 
430 	if (priv->pll_freq_kbps >= 501000)
431 		fr = 3;
432 	else if (priv->pll_freq_kbps >= 251000)
433 		fr = 2;
434 	else if (priv->pll_freq_kbps >= 126000)
435 		fr = 1;
436 
437 	return (fr << 14) | (div_factor << 8) | mul_factor;
438 }
439 
440 static int ssd2825_setup_pll(struct ssd2825_priv *priv,
441 			     const struct drm_display_mode *mode)
442 {
443 	u16 pll_config, lp_div;
444 	u32 nibble_delay, pclk_mult, tx_freq_khz;
445 	u8 hzd, hpd;
446 
447 	tx_freq_khz = clk_get_rate(priv->tx_clk) / KILO;
448 	if (!tx_freq_khz)
449 		tx_freq_khz = SSD2825_REF_MIN_CLK;
450 
451 	pclk_mult = priv->pd_lines / priv->dsi_lanes + 1;
452 	pll_config = construct_pll_config(priv, pclk_mult * mode->clock,
453 					  tx_freq_khz);
454 
455 	lp_div = priv->pll_freq_kbps / (SSD2825_LP_MIN_CLK * 8);
456 
457 	/* nibble_delay in nanoseconds */
458 	nibble_delay = MICRO / priv->nibble_freq_khz;
459 
460 	hzd = priv->hzd / nibble_delay;
461 	hpd = (priv->hpd - 4 * nibble_delay) / nibble_delay;
462 
463 	/* Disable PLL */
464 	ssd2825_write_reg(priv, SSD2825_PLL_CTRL_REG, 0x0000);
465 	ssd2825_write_reg(priv, SSD2825_LINE_CTRL_REG, 0x0001);
466 
467 	/* Set delays */
468 	ssd2825_write_reg(priv, SSD2825_DELAY_ADJ_REG_1, (hzd << 8) | hpd);
469 
470 	/* Set PLL coefficients */
471 	ssd2825_write_reg(priv, SSD2825_PLL_CONFIGURATION_REG, pll_config);
472 
473 	/* Clock Control Register */
474 	ssd2825_write_reg(priv, SSD2825_CLOCK_CTRL_REG,
475 			  SSD2828_LP_CLOCK_DIVIDER(lp_div));
476 
477 	/* Enable PLL */
478 	ssd2825_write_reg(priv, SSD2825_PLL_CTRL_REG, 0x0001);
479 	ssd2825_write_reg(priv, SSD2825_VC_CTRL_REG, 0);
480 
481 	return 0;
482 }
483 
484 static void ssd2825_bridge_atomic_pre_enable(struct drm_bridge *bridge,
485 					     struct drm_atomic_state *state)
486 {
487 	struct ssd2825_priv *priv = bridge_to_ssd2825(bridge);
488 	struct mipi_dsi_device *dsi_dev = priv->output.dev;
489 	const struct drm_crtc_state *crtc_state;
490 	const struct drm_display_mode *mode;
491 	struct drm_connector *connector;
492 	struct drm_crtc *crtc;
493 	u32 input_bus_flags = bridge->timings->input_bus_flags;
494 	u16 flags = 0, config;
495 	u8 pixel_format;
496 	int ret;
497 
498 	/* Power Sequence */
499 	ret = clk_prepare_enable(priv->tx_clk);
500 	if (ret)
501 		dev_err(priv->dev, "error enabling tx_clk (%d)\n", ret);
502 
503 	ret = regulator_bulk_enable(ARRAY_SIZE(ssd2825_supplies), priv->supplies);
504 	if (ret)
505 		dev_err(priv->dev, "error enabling regulators (%d)\n", ret);
506 
507 	usleep_range(1000, 2000);
508 
509 	ssd2825_hw_reset(priv);
510 
511 	/* Perform SW reset */
512 	ssd2825_write_reg(priv, SSD2825_OPERATION_CTRL_REG, 0x0100);
513 
514 	/* Set pixel format */
515 	switch (dsi_dev->format) {
516 	case MIPI_DSI_FMT_RGB565:
517 		pixel_format = 0x00;
518 		break;
519 	case MIPI_DSI_FMT_RGB666_PACKED:
520 		pixel_format = 0x01;
521 		break;
522 	case MIPI_DSI_FMT_RGB666:
523 		pixel_format = 0x02;
524 		break;
525 	case MIPI_DSI_FMT_RGB888:
526 	default:
527 		pixel_format = 0x03;
528 		break;
529 	}
530 
531 	connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
532 	crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
533 	crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
534 	mode = &crtc_state->adjusted_mode;
535 
536 	/* Set panel timings */
537 	ssd2825_write_reg(priv, SSD2825_RGB_INTERFACE_CTRL_REG_1,
538 			  ((mode->vtotal - mode->vsync_end) << 8) |
539 			  (mode->htotal - mode->hsync_end));
540 	ssd2825_write_reg(priv, SSD2825_RGB_INTERFACE_CTRL_REG_2,
541 			  ((mode->vtotal - mode->vsync_start) << 8) |
542 			  (mode->htotal - mode->hsync_start));
543 	ssd2825_write_reg(priv, SSD2825_RGB_INTERFACE_CTRL_REG_3,
544 			  ((mode->vsync_start - mode->vdisplay) << 8) |
545 			  (mode->hsync_start - mode->hdisplay));
546 	ssd2825_write_reg(priv, SSD2825_RGB_INTERFACE_CTRL_REG_4, mode->hdisplay);
547 	ssd2825_write_reg(priv, SSD2825_RGB_INTERFACE_CTRL_REG_5, mode->vdisplay);
548 
549 	if (mode->flags & DRM_MODE_FLAG_PHSYNC)
550 		flags |= SSD2825_HSYNC_HIGH;
551 
552 	if (mode->flags & DRM_MODE_FLAG_PVSYNC)
553 		flags |= SSD2825_VSYNC_HIGH;
554 
555 	if (dsi_dev->mode_flags & MIPI_DSI_MODE_VIDEO)
556 		flags |= SSD2825_NON_BURST_EV;
557 
558 	if (input_bus_flags & DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE)
559 		flags |= SSD2825_PCKL_HIGH;
560 
561 	ssd2825_write_reg(priv, SSD2825_RGB_INTERFACE_CTRL_REG_6, flags | pixel_format);
562 	ssd2825_write_reg(priv, SSD2825_LANE_CONFIGURATION_REG, dsi_dev->lanes - 1);
563 	ssd2825_write_reg(priv, SSD2825_TEST_REG, 0x0004);
564 
565 	/* Call PLL configuration */
566 	ssd2825_setup_pll(priv, mode);
567 
568 	usleep_range(10000, 11000);
569 
570 	config = SSD2825_CONF_REG_HS | SSD2825_CONF_REG_CKE | SSD2825_CONF_REG_DCS |
571 		 SSD2825_CONF_REG_ECD | SSD2825_CONF_REG_EOT;
572 
573 	if (dsi_dev->mode_flags & MIPI_DSI_MODE_LPM)
574 		config &= ~SSD2825_CONF_REG_HS;
575 
576 	if (dsi_dev->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET)
577 		config &= ~SSD2825_CONF_REG_EOT;
578 
579 	/* Initial DSI configuration register set */
580 	ssd2825_write_reg(priv, SSD2825_CONFIGURATION_REG, config);
581 	ssd2825_write_reg(priv, SSD2825_VC_CTRL_REG, 0);
582 
583 	if (priv->output.panel)
584 		drm_panel_enable(priv->output.panel);
585 }
586 
587 static void ssd2825_bridge_atomic_enable(struct drm_bridge *bridge,
588 					 struct drm_atomic_state *state)
589 {
590 	struct ssd2825_priv *priv = bridge_to_ssd2825(bridge);
591 	struct mipi_dsi_device *dsi_dev = priv->output.dev;
592 	u16 config;
593 
594 	config = SSD2825_CONF_REG_HS | SSD2825_CONF_REG_DCS |
595 		 SSD2825_CONF_REG_ECD | SSD2825_CONF_REG_EOT;
596 
597 	if (dsi_dev->mode_flags & MIPI_DSI_MODE_VIDEO)
598 		config |= SSD2825_CONF_REG_VEN;
599 
600 	if (dsi_dev->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET)
601 		config &= ~SSD2825_CONF_REG_EOT;
602 
603 	/* Complete configuration after DSI commands were sent */
604 	ssd2825_write_reg(priv, SSD2825_CONFIGURATION_REG, config);
605 	ssd2825_write_reg(priv, SSD2825_PLL_CTRL_REG, 0x0001);
606 	ssd2825_write_reg(priv, SSD2825_VC_CTRL_REG, 0x0000);
607 }
608 
609 static void ssd2825_bridge_atomic_disable(struct drm_bridge *bridge,
610 					  struct drm_atomic_state *state)
611 {
612 	struct ssd2825_priv *priv = bridge_to_ssd2825(bridge);
613 	int ret;
614 
615 	msleep(100);
616 
617 	/* Exit DSI configuration register set */
618 	ssd2825_write_reg(priv, SSD2825_CONFIGURATION_REG,
619 			  SSD2825_CONF_REG_ECD | SSD2825_CONF_REG_EOT);
620 	ssd2825_write_reg(priv, SSD2825_VC_CTRL_REG, 0);
621 
622 	/* HW disable */
623 	gpiod_set_value_cansleep(priv->reset_gpio, 1);
624 	usleep_range(5000, 6000);
625 
626 	ret = regulator_bulk_disable(ARRAY_SIZE(ssd2825_supplies),
627 				     priv->supplies);
628 	if (ret < 0)
629 		dev_err(priv->dev, "error disabling regulators (%d)\n", ret);
630 
631 	clk_disable_unprepare(priv->tx_clk);
632 }
633 
634 static int ssd2825_bridge_attach(struct drm_bridge *bridge, struct drm_encoder *encoder,
635 				 enum drm_bridge_attach_flags flags)
636 {
637 	struct ssd2825_priv *priv = bridge_to_ssd2825(bridge);
638 
639 	return drm_bridge_attach(bridge->encoder, priv->output.bridge, bridge,
640 				 flags);
641 }
642 
643 static enum drm_mode_status
644 ssd2825_bridge_mode_valid(struct drm_bridge *bridge,
645 			  const struct drm_display_info *info,
646 			  const struct drm_display_mode *mode)
647 {
648 	if (mode->hdisplay > 1366)
649 		return MODE_H_ILLEGAL;
650 
651 	if (mode->vdisplay > 1366)
652 		return MODE_V_ILLEGAL;
653 
654 	return MODE_OK;
655 }
656 
657 static bool ssd2825_mode_fixup(struct drm_bridge *bridge,
658 			       const struct drm_display_mode *mode,
659 			       struct drm_display_mode *adjusted_mode)
660 {
661 	/* Default to positive sync */
662 
663 	if (!(adjusted_mode->flags &
664 	      (DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_NHSYNC)))
665 		adjusted_mode->flags |= DRM_MODE_FLAG_PHSYNC;
666 
667 	if (!(adjusted_mode->flags &
668 	      (DRM_MODE_FLAG_PVSYNC | DRM_MODE_FLAG_NVSYNC)))
669 		adjusted_mode->flags |= DRM_MODE_FLAG_PVSYNC;
670 
671 	return true;
672 }
673 
674 static const struct drm_bridge_funcs ssd2825_bridge_funcs = {
675 	.attach = ssd2825_bridge_attach,
676 	.mode_valid = ssd2825_bridge_mode_valid,
677 	.mode_fixup = ssd2825_mode_fixup,
678 
679 	.atomic_pre_enable = ssd2825_bridge_atomic_pre_enable,
680 	.atomic_enable = ssd2825_bridge_atomic_enable,
681 	.atomic_disable = ssd2825_bridge_atomic_disable,
682 
683 	.atomic_reset = drm_atomic_helper_bridge_reset,
684 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
685 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
686 };
687 
688 static const struct drm_bridge_timings default_ssd2825_timings = {
689 	.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE
690 		 | DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE
691 		 | DRM_BUS_FLAG_DE_HIGH,
692 };
693 
694 static int ssd2825_probe(struct spi_device *spi)
695 {
696 	struct ssd2825_priv *priv;
697 	struct device *dev = &spi->dev;
698 	struct device_node *np = dev->of_node;
699 	int ret;
700 
701 	/* Driver supports only 8 bit 3 Wire mode */
702 	spi->bits_per_word = 9;
703 
704 	ret = spi_setup(spi);
705 	if (ret)
706 		return ret;
707 
708 	priv = devm_drm_bridge_alloc(dev, struct ssd2825_priv, bridge, &ssd2825_bridge_funcs);
709 	if (IS_ERR(priv))
710 		return PTR_ERR(priv);
711 
712 	spi_set_drvdata(spi, priv);
713 
714 	priv->spi = spi;
715 	priv->dev = dev;
716 
717 	mutex_init(&priv->mlock);
718 
719 	priv->tx_clk = devm_clk_get_optional(dev, NULL);
720 	if (IS_ERR(priv->tx_clk))
721 		return dev_err_probe(dev, PTR_ERR(priv->tx_clk),
722 				     "can't retrieve bridge tx_clk\n");
723 
724 	priv->reset_gpio = devm_gpiod_get_optional(dev, "reset",
725 						   GPIOD_OUT_HIGH);
726 	if (IS_ERR(priv->reset_gpio))
727 		return dev_err_probe(dev, PTR_ERR(priv->reset_gpio),
728 				     "failed to get reset GPIO\n");
729 
730 	ret = devm_regulator_bulk_get_const(dev, ARRAY_SIZE(ssd2825_supplies),
731 					    ssd2825_supplies, &priv->supplies);
732 	if (ret)
733 		return dev_err_probe(dev, ret, "failed to get regulators\n");
734 
735 	priv->hzd = 133; /* ns */
736 	device_property_read_u32(dev, "solomon,hs-zero-delay-ns", &priv->hzd);
737 
738 	priv->hpd = 40; /* ns */
739 	device_property_read_u32(dev, "solomon,hs-prep-delay-ns", &priv->hpd);
740 
741 	priv->dsi_host.dev = dev;
742 	priv->dsi_host.ops = &ssd2825_dsi_host_ops;
743 
744 	priv->bridge.timings = &default_ssd2825_timings;
745 	priv->bridge.of_node = np;
746 
747 	return mipi_dsi_host_register(&priv->dsi_host);
748 }
749 
750 static void ssd2825_remove(struct spi_device *spi)
751 {
752 	struct ssd2825_priv *priv = spi_get_drvdata(spi);
753 
754 	mipi_dsi_host_unregister(&priv->dsi_host);
755 }
756 
757 static const struct of_device_id ssd2825_of_match[] = {
758 	{ .compatible = "solomon,ssd2825" },
759 	{ /* sentinel */ }
760 };
761 MODULE_DEVICE_TABLE(of, ssd2825_of_match);
762 
763 static struct spi_driver ssd2825_driver = {
764 	.driver = {
765 		.name = "ssd2825",
766 		.of_match_table = ssd2825_of_match,
767 	},
768 	.probe = ssd2825_probe,
769 	.remove = ssd2825_remove,
770 };
771 module_spi_driver(ssd2825_driver);
772 
773 MODULE_AUTHOR("Svyatoslav Ryhel <clamor95@gmail.com>");
774 MODULE_DESCRIPTION("Solomon SSD2825 RGB to MIPI-DSI bridge driver SPI");
775 MODULE_LICENSE("GPL");
776