1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2020 Amarula Solutions(India)
4  * Author: Jagan Teki <jagan@amarulasolutions.com>
5  */
6 
7 #include <drm/drm_atomic_helper.h>
8 #include <drm/drm_of.h>
9 #include <drm/drm_print.h>
10 #include <drm/drm_mipi_dsi.h>
11 
12 #include <linux/delay.h>
13 #include <linux/gpio/consumer.h>
14 #include <linux/i2c.h>
15 #include <linux/module.h>
16 #include <linux/of_device.h>
17 #include <linux/regmap.h>
18 #include <linux/regulator/consumer.h>
19 
20 #define VENDOR_ID		0x00
21 #define DEVICE_ID_H		0x01
22 #define DEVICE_ID_L		0x02
23 #define VERSION_ID		0x03
24 #define FIRMWARE_VERSION	0x08
25 #define CONFIG_FINISH		0x09
26 #define PD_CTRL(n)		(0x0a + ((n) & 0x3)) /* 0..3 */
27 #define RST_CTRL(n)		(0x0e + ((n) & 0x1)) /* 0..1 */
28 #define SYS_CTRL(n)		(0x10 + ((n) & 0x7)) /* 0..4 */
29 #define RGB_DRV(n)		(0x18 + ((n) & 0x3)) /* 0..3 */
30 #define RGB_DLY(n)		(0x1c + ((n) & 0x1)) /* 0..1 */
31 #define RGB_TEST_CTRL		0x1e
32 #define ATE_PLL_EN		0x1f
33 #define HACTIVE_LI		0x20
34 #define VACTIVE_LI		0x21
35 #define VACTIVE_HACTIVE_HI	0x22
36 #define HFP_LI			0x23
37 #define HSYNC_LI		0x24
38 #define HBP_LI			0x25
39 #define HFP_HSW_HBP_HI		0x26
40 #define HFP_HSW_HBP_HI_HFP(n)		(((n) & 0x300) >> 4)
41 #define HFP_HSW_HBP_HI_HS(n)		(((n) & 0x300) >> 6)
42 #define HFP_HSW_HBP_HI_HBP(n)		(((n) & 0x300) >> 8)
43 #define VFP			0x27
44 #define VSYNC			0x28
45 #define VBP			0x29
46 #define BIST_POL		0x2a
47 #define BIST_POL_BIST_MODE(n)		(((n) & 0xf) << 4)
48 #define BIST_POL_BIST_GEN		BIT(3)
49 #define BIST_POL_HSYNC_POL		BIT(2)
50 #define BIST_POL_VSYNC_POL		BIT(1)
51 #define BIST_POL_DE_POL			BIT(0)
52 #define BIST_RED		0x2b
53 #define BIST_GREEN		0x2c
54 #define BIST_BLUE		0x2d
55 #define BIST_CHESS_X		0x2e
56 #define BIST_CHESS_Y		0x2f
57 #define BIST_CHESS_XY_H		0x30
58 #define BIST_FRAME_TIME_L	0x31
59 #define BIST_FRAME_TIME_H	0x32
60 #define FIFO_MAX_ADDR_LOW	0x33
61 #define SYNC_EVENT_DLY		0x34
62 #define HSW_MIN			0x35
63 #define HFP_MIN			0x36
64 #define LOGIC_RST_NUM		0x37
65 #define OSC_CTRL(n)		(0x48 + ((n) & 0x7)) /* 0..5 */
66 #define BG_CTRL			0x4e
67 #define LDO_PLL			0x4f
68 #define PLL_CTRL(n)		(0x50 + ((n) & 0xf)) /* 0..15 */
69 #define PLL_CTRL_6_EXTERNAL		0x90
70 #define PLL_CTRL_6_MIPI_CLK		0x92
71 #define PLL_CTRL_6_INTERNAL		0x93
72 #define PLL_REM(n)		(0x60 + ((n) & 0x3)) /* 0..2 */
73 #define PLL_DIV(n)		(0x63 + ((n) & 0x3)) /* 0..2 */
74 #define PLL_FRAC(n)		(0x66 + ((n) & 0x3)) /* 0..2 */
75 #define PLL_INT(n)		(0x69 + ((n) & 0x1)) /* 0..1 */
76 #define PLL_REF_DIV		0x6b
77 #define PLL_REF_DIV_P(n)		((n) & 0xf)
78 #define PLL_REF_DIV_Pe			BIT(4)
79 #define PLL_REF_DIV_S(n)		(((n) & 0x7) << 5)
80 #define PLL_SSC_P(n)		(0x6c + ((n) & 0x3)) /* 0..2 */
81 #define PLL_SSC_STEP(n)		(0x6f + ((n) & 0x3)) /* 0..2 */
82 #define PLL_SSC_OFFSET(n)	(0x72 + ((n) & 0x3)) /* 0..3 */
83 #define GPIO_OEN		0x79
84 #define MIPI_CFG_PW		0x7a
85 #define MIPI_CFG_PW_CONFIG_DSI		0xc1
86 #define MIPI_CFG_PW_CONFIG_I2C		0x3e
87 #define GPIO_SEL(n)		(0x7b + ((n) & 0x1)) /* 0..1 */
88 #define IRQ_SEL			0x7d
89 #define DBG_SEL			0x7e
90 #define DBG_SIGNAL		0x7f
91 #define MIPI_ERR_VECTOR_L	0x80
92 #define MIPI_ERR_VECTOR_H	0x81
93 #define MIPI_ERR_VECTOR_EN_L	0x82
94 #define MIPI_ERR_VECTOR_EN_H	0x83
95 #define MIPI_MAX_SIZE_L		0x84
96 #define MIPI_MAX_SIZE_H		0x85
97 #define DSI_CTRL		0x86
98 #define DSI_CTRL_UNKNOWN		0x28
99 #define DSI_CTRL_DSI_LANES(n)		((n) & 0x3)
100 #define MIPI_PN_SWAP		0x87
101 #define MIPI_PN_SWAP_CLK		BIT(4)
102 #define MIPI_PN_SWAP_D(n)		BIT((n) & 0x3)
103 #define MIPI_SOT_SYNC_BIT(n)	(0x88 + ((n) & 0x1)) /* 0..1 */
104 #define MIPI_ULPS_CTRL		0x8a
105 #define MIPI_CLK_CHK_VAR	0x8e
106 #define MIPI_CLK_CHK_INI	0x8f
107 #define MIPI_T_TERM_EN		0x90
108 #define MIPI_T_HS_SETTLE	0x91
109 #define MIPI_T_TA_SURE_PRE	0x92
110 #define MIPI_T_LPX_SET		0x94
111 #define MIPI_T_CLK_MISS		0x95
112 #define MIPI_INIT_TIME_L	0x96
113 #define MIPI_INIT_TIME_H	0x97
114 #define MIPI_T_CLK_TERM_EN	0x99
115 #define MIPI_T_CLK_SETTLE	0x9a
116 #define MIPI_TO_HS_RX_L		0x9e
117 #define MIPI_TO_HS_RX_H		0x9f
118 #define MIPI_PHY(n)		(0xa0 + ((n) & 0x7)) /* 0..5 */
119 #define MIPI_PD_RX		0xb0
120 #define MIPI_PD_TERM		0xb1
121 #define MIPI_PD_HSRX		0xb2
122 #define MIPI_PD_LPTX		0xb3
123 #define MIPI_PD_LPRX		0xb4
124 #define MIPI_PD_CK_LANE		0xb5
125 #define MIPI_FORCE_0		0xb6
126 #define MIPI_RST_CTRL		0xb7
127 #define MIPI_RST_NUM		0xb8
128 #define MIPI_DBG_SET(n)		(0xc0 + ((n) & 0xf)) /* 0..9 */
129 #define MIPI_DBG_SEL		0xe0
130 #define MIPI_DBG_DATA		0xe1
131 #define MIPI_ATE_TEST_SEL	0xe2
132 #define MIPI_ATE_STATUS(n)	(0xe3 + ((n) & 0x1)) /* 0..1 */
133 
134 struct chipone {
135 	struct device *dev;
136 	struct regmap *regmap;
137 	struct i2c_client *client;
138 	struct drm_bridge bridge;
139 	struct drm_display_mode mode;
140 	struct drm_bridge *panel_bridge;
141 	struct mipi_dsi_device *dsi;
142 	struct gpio_desc *enable_gpio;
143 	struct regulator *vdd1;
144 	struct regulator *vdd2;
145 	struct regulator *vdd3;
146 	bool interface_i2c;
147 };
148 
149 static const struct regmap_range chipone_dsi_readable_ranges[] = {
150 	regmap_reg_range(VENDOR_ID, VERSION_ID),
151 	regmap_reg_range(FIRMWARE_VERSION, PLL_SSC_OFFSET(3)),
152 	regmap_reg_range(GPIO_OEN, MIPI_ULPS_CTRL),
153 	regmap_reg_range(MIPI_CLK_CHK_VAR, MIPI_T_TA_SURE_PRE),
154 	regmap_reg_range(MIPI_T_LPX_SET, MIPI_INIT_TIME_H),
155 	regmap_reg_range(MIPI_T_CLK_TERM_EN, MIPI_T_CLK_SETTLE),
156 	regmap_reg_range(MIPI_TO_HS_RX_L, MIPI_PHY(5)),
157 	regmap_reg_range(MIPI_PD_RX, MIPI_RST_NUM),
158 	regmap_reg_range(MIPI_DBG_SET(0), MIPI_DBG_SET(9)),
159 	regmap_reg_range(MIPI_DBG_SEL, MIPI_ATE_STATUS(1)),
160 };
161 
162 static const struct regmap_access_table chipone_dsi_readable_table = {
163 	.yes_ranges = chipone_dsi_readable_ranges,
164 	.n_yes_ranges = ARRAY_SIZE(chipone_dsi_readable_ranges),
165 };
166 
167 static const struct regmap_range chipone_dsi_writeable_ranges[] = {
168 	regmap_reg_range(CONFIG_FINISH, PLL_SSC_OFFSET(3)),
169 	regmap_reg_range(GPIO_OEN, MIPI_ULPS_CTRL),
170 	regmap_reg_range(MIPI_CLK_CHK_VAR, MIPI_T_TA_SURE_PRE),
171 	regmap_reg_range(MIPI_T_LPX_SET, MIPI_INIT_TIME_H),
172 	regmap_reg_range(MIPI_T_CLK_TERM_EN, MIPI_T_CLK_SETTLE),
173 	regmap_reg_range(MIPI_TO_HS_RX_L, MIPI_PHY(5)),
174 	regmap_reg_range(MIPI_PD_RX, MIPI_RST_NUM),
175 	regmap_reg_range(MIPI_DBG_SET(0), MIPI_DBG_SET(9)),
176 	regmap_reg_range(MIPI_DBG_SEL, MIPI_ATE_STATUS(1)),
177 };
178 
179 static const struct regmap_access_table chipone_dsi_writeable_table = {
180 	.yes_ranges = chipone_dsi_writeable_ranges,
181 	.n_yes_ranges = ARRAY_SIZE(chipone_dsi_writeable_ranges),
182 };
183 
184 static const struct regmap_config chipone_regmap_config = {
185 	.reg_bits = 8,
186 	.val_bits = 8,
187 	.rd_table = &chipone_dsi_readable_table,
188 	.wr_table = &chipone_dsi_writeable_table,
189 	.cache_type = REGCACHE_RBTREE,
190 	.max_register = MIPI_ATE_STATUS(1),
191 };
192 
193 static int chipone_dsi_read(void *context,
194 			    const void *reg, size_t reg_size,
195 			    void *val, size_t val_size)
196 {
197 	struct mipi_dsi_device *dsi = context;
198 	const u16 reg16 = (val_size << 8) | *(u8 *)reg;
199 	int ret;
200 
201 	ret = mipi_dsi_generic_read(dsi, &reg16, 2, val, val_size);
202 
203 	return ret == val_size ? 0 : -EINVAL;
204 }
205 
206 static int chipone_dsi_write(void *context, const void *data, size_t count)
207 {
208 	struct mipi_dsi_device *dsi = context;
209 
210 	return mipi_dsi_generic_write(dsi, data, 2);
211 }
212 
213 static const struct regmap_bus chipone_dsi_regmap_bus = {
214 	.read				= chipone_dsi_read,
215 	.write				= chipone_dsi_write,
216 	.reg_format_endian_default	= REGMAP_ENDIAN_NATIVE,
217 	.val_format_endian_default	= REGMAP_ENDIAN_NATIVE,
218 };
219 
220 static inline struct chipone *bridge_to_chipone(struct drm_bridge *bridge)
221 {
222 	return container_of(bridge, struct chipone, bridge);
223 }
224 
225 static void chipone_readb(struct chipone *icn, u8 reg, u8 *val)
226 {
227 	int ret, pval;
228 
229 	ret = regmap_read(icn->regmap, reg, &pval);
230 
231 	*val = ret ? 0 : pval & 0xff;
232 }
233 
234 static int chipone_writeb(struct chipone *icn, u8 reg, u8 val)
235 {
236 	return regmap_write(icn->regmap, reg, val);
237 }
238 
239 static void chipone_configure_pll(struct chipone *icn,
240 				  const struct drm_display_mode *mode)
241 {
242 	unsigned int best_p = 0, best_m = 0, best_s = 0;
243 	unsigned int mode_clock = mode->clock * 1000;
244 	unsigned int delta, min_delta = 0xffffffff;
245 	unsigned int freq_p, freq_s, freq_out;
246 	unsigned int p_min, p_max;
247 	unsigned int p, m, s;
248 	unsigned int fin;
249 	bool best_p_pot;
250 	u8 ref_div;
251 
252 	/*
253 	 * DSI byte clock frequency (input into PLL) is calculated as:
254 	 *  DSI_CLK = mode clock * bpp / dsi_data_lanes / 8
255 	 *
256 	 * DPI pixel clock frequency (output from PLL) is mode clock.
257 	 *
258 	 * The chip contains fractional PLL which works as follows:
259 	 *  DPI_CLK = ((DSI_CLK / P) * M) / S
260 	 * P is pre-divider, register PLL_REF_DIV[3:0] is 1:n divider
261 	 *                   register PLL_REF_DIV[4] is extra 1:2 divider
262 	 * M is integer multiplier, register PLL_INT(0) is multiplier
263 	 * S is post-divider, register PLL_REF_DIV[7:5] is 2^(n+1) divider
264 	 *
265 	 * It seems the PLL input clock after applying P pre-divider have
266 	 * to be lower than 20 MHz.
267 	 */
268 	fin = mode_clock * mipi_dsi_pixel_format_to_bpp(icn->dsi->format) /
269 	      icn->dsi->lanes / 8; /* in Hz */
270 
271 	/* Minimum value of P predivider for PLL input in 5..20 MHz */
272 	p_min = clamp(DIV_ROUND_UP(fin, 20000000), 1U, 31U);
273 	p_max = clamp(fin / 5000000, 1U, 31U);
274 
275 	for (p = p_min; p < p_max; p++) {	/* PLL_REF_DIV[4,3:0] */
276 		if (p > 16 && p & 1)		/* P > 16 uses extra /2 */
277 			continue;
278 		freq_p = fin / p;
279 		if (freq_p == 0)		/* Divider too high */
280 			break;
281 
282 		for (s = 0; s < 0x7; s++) {	/* PLL_REF_DIV[7:5] */
283 			freq_s = freq_p / BIT(s + 1);
284 			if (freq_s == 0)	/* Divider too high */
285 				break;
286 
287 			m = mode_clock / freq_s;
288 
289 			/* Multiplier is 8 bit */
290 			if (m > 0xff)
291 				continue;
292 
293 			/* Limit PLL VCO frequency to 1 GHz */
294 			freq_out = (fin * m) / p;
295 			if (freq_out > 1000000000)
296 				continue;
297 
298 			/* Apply post-divider */
299 			freq_out /= BIT(s + 1);
300 
301 			delta = abs(mode_clock - freq_out);
302 			if (delta < min_delta) {
303 				best_p = p;
304 				best_m = m;
305 				best_s = s;
306 				min_delta = delta;
307 			}
308 		}
309 	}
310 
311 	best_p_pot = !(best_p & 1);
312 
313 	dev_dbg(icn->dev,
314 		"PLL: P[3:0]=%d P[4]=2*%d M=%d S[7:5]=2^%d delta=%d => DSI f_in=%d Hz ; DPI f_out=%d Hz\n",
315 		best_p >> best_p_pot, best_p_pot, best_m, best_s + 1,
316 		min_delta, fin, (fin * best_m) / (best_p << (best_s + 1)));
317 
318 	ref_div = PLL_REF_DIV_P(best_p >> best_p_pot) | PLL_REF_DIV_S(best_s);
319 	if (best_p_pot)	/* Prefer /2 pre-divider */
320 		ref_div |= PLL_REF_DIV_Pe;
321 
322 	/* Clock source selection fixed to MIPI DSI clock lane */
323 	chipone_writeb(icn, PLL_CTRL(6), PLL_CTRL_6_MIPI_CLK);
324 	chipone_writeb(icn, PLL_REF_DIV, ref_div);
325 	chipone_writeb(icn, PLL_INT(0), best_m);
326 }
327 
328 static void chipone_atomic_enable(struct drm_bridge *bridge,
329 				  struct drm_bridge_state *old_bridge_state)
330 {
331 	struct chipone *icn = bridge_to_chipone(bridge);
332 	struct drm_atomic_state *state = old_bridge_state->base.state;
333 	struct drm_display_mode *mode = &icn->mode;
334 	const struct drm_bridge_state *bridge_state;
335 	u16 hfp, hbp, hsync;
336 	u32 bus_flags;
337 	u8 pol, id[4];
338 
339 	chipone_readb(icn, VENDOR_ID, id);
340 	chipone_readb(icn, DEVICE_ID_H, id + 1);
341 	chipone_readb(icn, DEVICE_ID_L, id + 2);
342 	chipone_readb(icn, VERSION_ID, id + 3);
343 
344 	dev_dbg(icn->dev,
345 		"Chip IDs: Vendor=0x%02x Device=0x%02x:0x%02x Version=0x%02x\n",
346 		id[0], id[1], id[2], id[3]);
347 
348 	if (id[0] != 0xc1 || id[1] != 0x62 || id[2] != 0x11) {
349 		dev_dbg(icn->dev, "Invalid Chip IDs, aborting configuration\n");
350 		return;
351 	}
352 
353 	/* Get the DPI flags from the bridge state. */
354 	bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
355 	bus_flags = bridge_state->output_bus_cfg.flags;
356 
357 	if (icn->interface_i2c)
358 		chipone_writeb(icn, MIPI_CFG_PW, MIPI_CFG_PW_CONFIG_I2C);
359 	else
360 		chipone_writeb(icn, MIPI_CFG_PW, MIPI_CFG_PW_CONFIG_DSI);
361 
362 	chipone_writeb(icn, HACTIVE_LI, mode->hdisplay & 0xff);
363 
364 	chipone_writeb(icn, VACTIVE_LI, mode->vdisplay & 0xff);
365 
366 	/*
367 	 * lsb nibble: 2nd nibble of hdisplay
368 	 * msb nibble: 2nd nibble of vdisplay
369 	 */
370 	chipone_writeb(icn, VACTIVE_HACTIVE_HI,
371 		       ((mode->hdisplay >> 8) & 0xf) |
372 		       (((mode->vdisplay >> 8) & 0xf) << 4));
373 
374 	hfp = mode->hsync_start - mode->hdisplay;
375 	hsync = mode->hsync_end - mode->hsync_start;
376 	hbp = mode->htotal - mode->hsync_end;
377 
378 	chipone_writeb(icn, HFP_LI, hfp & 0xff);
379 	chipone_writeb(icn, HSYNC_LI, hsync & 0xff);
380 	chipone_writeb(icn, HBP_LI, hbp & 0xff);
381 	/* Top two bits of Horizontal Front porch/Sync/Back porch */
382 	chipone_writeb(icn, HFP_HSW_HBP_HI,
383 		       HFP_HSW_HBP_HI_HFP(hfp) |
384 		       HFP_HSW_HBP_HI_HS(hsync) |
385 		       HFP_HSW_HBP_HI_HBP(hbp));
386 
387 	chipone_writeb(icn, VFP, mode->vsync_start - mode->vdisplay);
388 
389 	chipone_writeb(icn, VSYNC, mode->vsync_end - mode->vsync_start);
390 
391 	chipone_writeb(icn, VBP, mode->vtotal - mode->vsync_end);
392 
393 	/* dsi specific sequence */
394 	chipone_writeb(icn, SYNC_EVENT_DLY, 0x80);
395 	chipone_writeb(icn, HFP_MIN, hfp & 0xff);
396 
397 	/* DSI data lane count */
398 	chipone_writeb(icn, DSI_CTRL,
399 		       DSI_CTRL_UNKNOWN | DSI_CTRL_DSI_LANES(icn->dsi->lanes - 1));
400 
401 	chipone_writeb(icn, MIPI_PD_CK_LANE, 0xa0);
402 	chipone_writeb(icn, PLL_CTRL(12), 0xff);
403 	chipone_writeb(icn, MIPI_PN_SWAP, 0x00);
404 
405 	/* DPI HS/VS/DE polarity */
406 	pol = ((mode->flags & DRM_MODE_FLAG_PHSYNC) ? BIST_POL_HSYNC_POL : 0) |
407 	      ((mode->flags & DRM_MODE_FLAG_PVSYNC) ? BIST_POL_VSYNC_POL : 0) |
408 	      ((bus_flags & DRM_BUS_FLAG_DE_HIGH) ? BIST_POL_DE_POL : 0);
409 	chipone_writeb(icn, BIST_POL, pol);
410 
411 	/* Configure PLL settings */
412 	chipone_configure_pll(icn, mode);
413 
414 	chipone_writeb(icn, SYS_CTRL(0), 0x40);
415 	chipone_writeb(icn, SYS_CTRL(1), 0x88);
416 
417 	/* icn6211 specific sequence */
418 	chipone_writeb(icn, MIPI_FORCE_0, 0x20);
419 	chipone_writeb(icn, PLL_CTRL(1), 0x20);
420 	chipone_writeb(icn, CONFIG_FINISH, 0x10);
421 
422 	usleep_range(10000, 11000);
423 }
424 
425 static void chipone_atomic_pre_enable(struct drm_bridge *bridge,
426 				      struct drm_bridge_state *old_bridge_state)
427 {
428 	struct chipone *icn = bridge_to_chipone(bridge);
429 	int ret;
430 
431 	if (icn->vdd1) {
432 		ret = regulator_enable(icn->vdd1);
433 		if (ret)
434 			DRM_DEV_ERROR(icn->dev,
435 				      "failed to enable VDD1 regulator: %d\n", ret);
436 	}
437 
438 	if (icn->vdd2) {
439 		ret = regulator_enable(icn->vdd2);
440 		if (ret)
441 			DRM_DEV_ERROR(icn->dev,
442 				      "failed to enable VDD2 regulator: %d\n", ret);
443 	}
444 
445 	if (icn->vdd3) {
446 		ret = regulator_enable(icn->vdd3);
447 		if (ret)
448 			DRM_DEV_ERROR(icn->dev,
449 				      "failed to enable VDD3 regulator: %d\n", ret);
450 	}
451 
452 	gpiod_set_value(icn->enable_gpio, 1);
453 
454 	usleep_range(10000, 11000);
455 }
456 
457 static void chipone_atomic_post_disable(struct drm_bridge *bridge,
458 					struct drm_bridge_state *old_bridge_state)
459 {
460 	struct chipone *icn = bridge_to_chipone(bridge);
461 
462 	if (icn->vdd1)
463 		regulator_disable(icn->vdd1);
464 
465 	if (icn->vdd2)
466 		regulator_disable(icn->vdd2);
467 
468 	if (icn->vdd3)
469 		regulator_disable(icn->vdd3);
470 
471 	gpiod_set_value(icn->enable_gpio, 0);
472 }
473 
474 static void chipone_mode_set(struct drm_bridge *bridge,
475 			     const struct drm_display_mode *mode,
476 			     const struct drm_display_mode *adjusted_mode)
477 {
478 	struct chipone *icn = bridge_to_chipone(bridge);
479 
480 	drm_mode_copy(&icn->mode, adjusted_mode);
481 };
482 
483 static int chipone_dsi_attach(struct chipone *icn)
484 {
485 	struct mipi_dsi_device *dsi = icn->dsi;
486 	struct device *dev = icn->dev;
487 	struct device_node *endpoint;
488 	int dsi_lanes, ret;
489 
490 	endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
491 	dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
492 	of_node_put(endpoint);
493 
494 	/*
495 	 * If the 'data-lanes' property does not exist in DT or is invalid,
496 	 * default to previously hard-coded behavior, which was 4 data lanes.
497 	 */
498 	if (dsi_lanes >= 1 && dsi_lanes <= 4)
499 		icn->dsi->lanes = dsi_lanes;
500 	else
501 		icn->dsi->lanes = 4;
502 
503 	dsi->format = MIPI_DSI_FMT_RGB888;
504 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
505 			  MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_NO_EOT_PACKET;
506 
507 	ret = mipi_dsi_attach(dsi);
508 	if (ret < 0)
509 		dev_err(icn->dev, "failed to attach dsi\n");
510 
511 	return ret;
512 }
513 
514 static int chipone_dsi_host_attach(struct chipone *icn)
515 {
516 	struct device *dev = icn->dev;
517 	struct device_node *host_node;
518 	struct device_node *endpoint;
519 	struct mipi_dsi_device *dsi;
520 	struct mipi_dsi_host *host;
521 	int ret = 0;
522 
523 	const struct mipi_dsi_device_info info = {
524 		.type = "chipone",
525 		.channel = 0,
526 		.node = NULL,
527 	};
528 
529 	endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
530 	host_node = of_graph_get_remote_port_parent(endpoint);
531 	of_node_put(endpoint);
532 
533 	if (!host_node)
534 		return -EINVAL;
535 
536 	host = of_find_mipi_dsi_host_by_node(host_node);
537 	of_node_put(host_node);
538 	if (!host) {
539 		dev_err(dev, "failed to find dsi host\n");
540 		return -EPROBE_DEFER;
541 	}
542 
543 	dsi = mipi_dsi_device_register_full(host, &info);
544 	if (IS_ERR(dsi)) {
545 		return dev_err_probe(dev, PTR_ERR(dsi),
546 				     "failed to create dsi device\n");
547 	}
548 
549 	icn->dsi = dsi;
550 
551 	ret = chipone_dsi_attach(icn);
552 	if (ret < 0)
553 		mipi_dsi_device_unregister(dsi);
554 
555 	return ret;
556 }
557 
558 static int chipone_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags)
559 {
560 	struct chipone *icn = bridge_to_chipone(bridge);
561 
562 	return drm_bridge_attach(bridge->encoder, icn->panel_bridge, bridge, flags);
563 }
564 
565 #define MAX_INPUT_SEL_FORMATS	1
566 
567 static u32 *
568 chipone_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
569 				  struct drm_bridge_state *bridge_state,
570 				  struct drm_crtc_state *crtc_state,
571 				  struct drm_connector_state *conn_state,
572 				  u32 output_fmt,
573 				  unsigned int *num_input_fmts)
574 {
575 	u32 *input_fmts;
576 
577 	*num_input_fmts = 0;
578 
579 	input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
580 			     GFP_KERNEL);
581 	if (!input_fmts)
582 		return NULL;
583 
584 	/* This is the DSI-end bus format */
585 	input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
586 	*num_input_fmts = 1;
587 
588 	return input_fmts;
589 }
590 
591 static const struct drm_bridge_funcs chipone_bridge_funcs = {
592 	.atomic_duplicate_state	= drm_atomic_helper_bridge_duplicate_state,
593 	.atomic_destroy_state	= drm_atomic_helper_bridge_destroy_state,
594 	.atomic_reset		= drm_atomic_helper_bridge_reset,
595 	.atomic_pre_enable	= chipone_atomic_pre_enable,
596 	.atomic_enable		= chipone_atomic_enable,
597 	.atomic_post_disable	= chipone_atomic_post_disable,
598 	.mode_set		= chipone_mode_set,
599 	.attach			= chipone_attach,
600 	.atomic_get_input_bus_fmts = chipone_atomic_get_input_bus_fmts,
601 };
602 
603 static int chipone_parse_dt(struct chipone *icn)
604 {
605 	struct device *dev = icn->dev;
606 	int ret;
607 
608 	icn->vdd1 = devm_regulator_get_optional(dev, "vdd1");
609 	if (IS_ERR(icn->vdd1)) {
610 		ret = PTR_ERR(icn->vdd1);
611 		if (ret == -EPROBE_DEFER)
612 			return -EPROBE_DEFER;
613 		icn->vdd1 = NULL;
614 		DRM_DEV_DEBUG(dev, "failed to get VDD1 regulator: %d\n", ret);
615 	}
616 
617 	icn->vdd2 = devm_regulator_get_optional(dev, "vdd2");
618 	if (IS_ERR(icn->vdd2)) {
619 		ret = PTR_ERR(icn->vdd2);
620 		if (ret == -EPROBE_DEFER)
621 			return -EPROBE_DEFER;
622 		icn->vdd2 = NULL;
623 		DRM_DEV_DEBUG(dev, "failed to get VDD2 regulator: %d\n", ret);
624 	}
625 
626 	icn->vdd3 = devm_regulator_get_optional(dev, "vdd3");
627 	if (IS_ERR(icn->vdd3)) {
628 		ret = PTR_ERR(icn->vdd3);
629 		if (ret == -EPROBE_DEFER)
630 			return -EPROBE_DEFER;
631 		icn->vdd3 = NULL;
632 		DRM_DEV_DEBUG(dev, "failed to get VDD3 regulator: %d\n", ret);
633 	}
634 
635 	icn->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
636 	if (IS_ERR(icn->enable_gpio)) {
637 		DRM_DEV_ERROR(dev, "failed to get enable GPIO\n");
638 		return PTR_ERR(icn->enable_gpio);
639 	}
640 
641 	icn->panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
642 	if (IS_ERR(icn->panel_bridge))
643 		return PTR_ERR(icn->panel_bridge);
644 
645 	return 0;
646 }
647 
648 static int chipone_common_probe(struct device *dev, struct chipone **icnr)
649 {
650 	struct chipone *icn;
651 	int ret;
652 
653 	icn = devm_kzalloc(dev, sizeof(struct chipone), GFP_KERNEL);
654 	if (!icn)
655 		return -ENOMEM;
656 
657 	icn->dev = dev;
658 
659 	ret = chipone_parse_dt(icn);
660 	if (ret)
661 		return ret;
662 
663 	icn->bridge.funcs = &chipone_bridge_funcs;
664 	icn->bridge.type = DRM_MODE_CONNECTOR_DPI;
665 	icn->bridge.of_node = dev->of_node;
666 
667 	*icnr = icn;
668 
669 	return ret;
670 }
671 
672 static int chipone_dsi_probe(struct mipi_dsi_device *dsi)
673 {
674 	struct device *dev = &dsi->dev;
675 	struct chipone *icn;
676 	int ret;
677 
678 	ret = chipone_common_probe(dev, &icn);
679 	if (ret)
680 		return ret;
681 
682 	icn->regmap = devm_regmap_init(dev, &chipone_dsi_regmap_bus,
683 				       dsi, &chipone_regmap_config);
684 	if (IS_ERR(icn->regmap))
685 		return PTR_ERR(icn->regmap);
686 
687 	icn->interface_i2c = false;
688 	icn->dsi = dsi;
689 
690 	mipi_dsi_set_drvdata(dsi, icn);
691 
692 	drm_bridge_add(&icn->bridge);
693 
694 	ret = chipone_dsi_attach(icn);
695 	if (ret)
696 		drm_bridge_remove(&icn->bridge);
697 
698 	return ret;
699 }
700 
701 static int chipone_i2c_probe(struct i2c_client *client,
702 			     const struct i2c_device_id *id)
703 {
704 	struct device *dev = &client->dev;
705 	struct chipone *icn;
706 	int ret;
707 
708 	ret = chipone_common_probe(dev, &icn);
709 	if (ret)
710 		return ret;
711 
712 	icn->regmap = devm_regmap_init_i2c(client, &chipone_regmap_config);
713 	if (IS_ERR(icn->regmap))
714 		return PTR_ERR(icn->regmap);
715 
716 	icn->interface_i2c = true;
717 	icn->client = client;
718 	dev_set_drvdata(dev, icn);
719 	i2c_set_clientdata(client, icn);
720 
721 	drm_bridge_add(&icn->bridge);
722 
723 	return chipone_dsi_host_attach(icn);
724 }
725 
726 static int chipone_dsi_remove(struct mipi_dsi_device *dsi)
727 {
728 	struct chipone *icn = mipi_dsi_get_drvdata(dsi);
729 
730 	mipi_dsi_detach(dsi);
731 	drm_bridge_remove(&icn->bridge);
732 
733 	return 0;
734 }
735 
736 static const struct of_device_id chipone_of_match[] = {
737 	{ .compatible = "chipone,icn6211", },
738 	{ /* sentinel */ }
739 };
740 MODULE_DEVICE_TABLE(of, chipone_of_match);
741 
742 static struct mipi_dsi_driver chipone_dsi_driver = {
743 	.probe = chipone_dsi_probe,
744 	.remove = chipone_dsi_remove,
745 	.driver = {
746 		.name = "chipone-icn6211",
747 		.owner = THIS_MODULE,
748 		.of_match_table = chipone_of_match,
749 	},
750 };
751 
752 static struct i2c_device_id chipone_i2c_id[] = {
753 	{ "chipone,icn6211" },
754 	{},
755 };
756 MODULE_DEVICE_TABLE(i2c, chipone_i2c_id);
757 
758 static struct i2c_driver chipone_i2c_driver = {
759 	.probe = chipone_i2c_probe,
760 	.id_table = chipone_i2c_id,
761 	.driver = {
762 		.name = "chipone-icn6211-i2c",
763 		.of_match_table = chipone_of_match,
764 	},
765 };
766 
767 static int __init chipone_init(void)
768 {
769 	if (IS_ENABLED(CONFIG_DRM_MIPI_DSI))
770 		mipi_dsi_driver_register(&chipone_dsi_driver);
771 
772 	return i2c_add_driver(&chipone_i2c_driver);
773 }
774 module_init(chipone_init);
775 
776 static void __exit chipone_exit(void)
777 {
778 	i2c_del_driver(&chipone_i2c_driver);
779 
780 	if (IS_ENABLED(CONFIG_DRM_MIPI_DSI))
781 		mipi_dsi_driver_unregister(&chipone_dsi_driver);
782 }
783 module_exit(chipone_exit);
784 
785 MODULE_AUTHOR("Jagan Teki <jagan@amarulasolutions.com>");
786 MODULE_DESCRIPTION("Chipone ICN6211 MIPI-DSI to RGB Converter Bridge");
787 MODULE_LICENSE("GPL");
788