1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * R-Car LVDS Encoder
4  *
5  * Copyright (C) 2013-2018 Renesas Electronics Corporation
6  *
7  * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
8  */
9 
10 #include <linux/clk.h>
11 #include <linux/delay.h>
12 #include <linux/io.h>
13 #include <linux/media-bus-format.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/of_device.h>
17 #include <linux/of_graph.h>
18 #include <linux/platform_device.h>
19 #include <linux/slab.h>
20 #include <linux/sys_soc.h>
21 
22 #include <drm/drm_atomic.h>
23 #include <drm/drm_atomic_helper.h>
24 #include <drm/drm_bridge.h>
25 #include <drm/drm_of.h>
26 #include <drm/drm_panel.h>
27 #include <drm/drm_print.h>
28 #include <drm/drm_probe_helper.h>
29 
30 #include "rcar_lvds.h"
31 #include "rcar_lvds_regs.h"
32 
33 struct rcar_lvds;
34 
35 /* Keep in sync with the LVDCR0.LVMD hardware register values. */
36 enum rcar_lvds_mode {
37 	RCAR_LVDS_MODE_JEIDA = 0,
38 	RCAR_LVDS_MODE_MIRROR = 1,
39 	RCAR_LVDS_MODE_VESA = 4,
40 };
41 
42 enum rcar_lvds_link_type {
43 	RCAR_LVDS_SINGLE_LINK = 0,
44 	RCAR_LVDS_DUAL_LINK_EVEN_ODD_PIXELS = 1,
45 	RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS = 2,
46 };
47 
48 #define RCAR_LVDS_QUIRK_LANES		BIT(0)	/* LVDS lanes 1 and 3 inverted */
49 #define RCAR_LVDS_QUIRK_GEN3_LVEN	BIT(1)	/* LVEN bit needs to be set on R8A77970/R8A7799x */
50 #define RCAR_LVDS_QUIRK_PWD		BIT(2)	/* PWD bit available (all of Gen3 but E3) */
51 #define RCAR_LVDS_QUIRK_EXT_PLL		BIT(3)	/* Has extended PLL */
52 #define RCAR_LVDS_QUIRK_DUAL_LINK	BIT(4)	/* Supports dual-link operation */
53 
54 struct rcar_lvds_device_info {
55 	unsigned int gen;
56 	unsigned int quirks;
57 	void (*pll_setup)(struct rcar_lvds *lvds, unsigned int freq);
58 };
59 
60 struct rcar_lvds {
61 	struct device *dev;
62 	const struct rcar_lvds_device_info *info;
63 
64 	struct drm_bridge bridge;
65 
66 	struct drm_bridge *next_bridge;
67 	struct drm_panel *panel;
68 
69 	void __iomem *mmio;
70 	struct {
71 		struct clk *mod;		/* CPG module clock */
72 		struct clk *extal;		/* External clock */
73 		struct clk *dotclkin[2];	/* External DU clocks */
74 	} clocks;
75 
76 	struct drm_bridge *companion;
77 	enum rcar_lvds_link_type link_type;
78 };
79 
80 #define bridge_to_rcar_lvds(b) \
81 	container_of(b, struct rcar_lvds, bridge)
82 
rcar_lvds_write(struct rcar_lvds * lvds,u32 reg,u32 data)83 static void rcar_lvds_write(struct rcar_lvds *lvds, u32 reg, u32 data)
84 {
85 	iowrite32(data, lvds->mmio + reg);
86 }
87 
88 /* -----------------------------------------------------------------------------
89  * PLL Setup
90  */
91 
rcar_lvds_pll_setup_gen2(struct rcar_lvds * lvds,unsigned int freq)92 static void rcar_lvds_pll_setup_gen2(struct rcar_lvds *lvds, unsigned int freq)
93 {
94 	u32 val;
95 
96 	if (freq < 39000000)
97 		val = LVDPLLCR_CEEN | LVDPLLCR_COSEL | LVDPLLCR_PLLDLYCNT_38M;
98 	else if (freq < 61000000)
99 		val = LVDPLLCR_CEEN | LVDPLLCR_COSEL | LVDPLLCR_PLLDLYCNT_60M;
100 	else if (freq < 121000000)
101 		val = LVDPLLCR_CEEN | LVDPLLCR_COSEL | LVDPLLCR_PLLDLYCNT_121M;
102 	else
103 		val = LVDPLLCR_PLLDLYCNT_150M;
104 
105 	rcar_lvds_write(lvds, LVDPLLCR, val);
106 }
107 
rcar_lvds_pll_setup_gen3(struct rcar_lvds * lvds,unsigned int freq)108 static void rcar_lvds_pll_setup_gen3(struct rcar_lvds *lvds, unsigned int freq)
109 {
110 	u32 val;
111 
112 	if (freq < 42000000)
113 		val = LVDPLLCR_PLLDIVCNT_42M;
114 	else if (freq < 85000000)
115 		val = LVDPLLCR_PLLDIVCNT_85M;
116 	else if (freq < 128000000)
117 		val = LVDPLLCR_PLLDIVCNT_128M;
118 	else
119 		val = LVDPLLCR_PLLDIVCNT_148M;
120 
121 	rcar_lvds_write(lvds, LVDPLLCR, val);
122 }
123 
124 struct pll_info {
125 	unsigned long diff;
126 	unsigned int pll_m;
127 	unsigned int pll_n;
128 	unsigned int pll_e;
129 	unsigned int div;
130 	u32 clksel;
131 };
132 
rcar_lvds_d3_e3_pll_calc(struct rcar_lvds * lvds,struct clk * clk,unsigned long target,struct pll_info * pll,u32 clksel,bool dot_clock_only)133 static void rcar_lvds_d3_e3_pll_calc(struct rcar_lvds *lvds, struct clk *clk,
134 				     unsigned long target, struct pll_info *pll,
135 				     u32 clksel, bool dot_clock_only)
136 {
137 	unsigned int div7 = dot_clock_only ? 1 : 7;
138 	unsigned long output;
139 	unsigned long fin;
140 	unsigned int m_min;
141 	unsigned int m_max;
142 	unsigned int m;
143 	int error;
144 
145 	if (!clk)
146 		return;
147 
148 	/*
149 	 * The LVDS PLL is made of a pre-divider and a multiplier (strangely
150 	 * enough called M and N respectively), followed by a post-divider E.
151 	 *
152 	 *         ,-----.         ,-----.     ,-----.         ,-----.
153 	 * Fin --> | 1/M | -Fpdf-> | PFD | --> | VCO | -Fvco-> | 1/E | --> Fout
154 	 *         `-----'     ,-> |     |     `-----'   |     `-----'
155 	 *                     |   `-----'               |
156 	 *                     |         ,-----.         |
157 	 *                     `-------- | 1/N | <-------'
158 	 *                               `-----'
159 	 *
160 	 * The clock output by the PLL is then further divided by a programmable
161 	 * divider DIV to achieve the desired target frequency. Finally, an
162 	 * optional fixed /7 divider is used to convert the bit clock to a pixel
163 	 * clock (as LVDS transmits 7 bits per lane per clock sample).
164 	 *
165 	 *          ,-------.     ,-----.     |\
166 	 * Fout --> | 1/DIV | --> | 1/7 | --> | |
167 	 *          `-------'  |  `-----'     | | --> dot clock
168 	 *                     `------------> | |
169 	 *                                    |/
170 	 *
171 	 * The /7 divider is optional, it is enabled when the LVDS PLL is used
172 	 * to drive the LVDS encoder, and disabled when  used to generate a dot
173 	 * clock for the DU RGB output, without using the LVDS encoder.
174 	 *
175 	 * The PLL allowed input frequency range is 12 MHz to 192 MHz.
176 	 */
177 
178 	fin = clk_get_rate(clk);
179 	if (fin < 12000000 || fin > 192000000)
180 		return;
181 
182 	/*
183 	 * The comparison frequency range is 12 MHz to 24 MHz, which limits the
184 	 * allowed values for the pre-divider M (normal range 1-8).
185 	 *
186 	 * Fpfd = Fin / M
187 	 */
188 	m_min = max_t(unsigned int, 1, DIV_ROUND_UP(fin, 24000000));
189 	m_max = min_t(unsigned int, 8, fin / 12000000);
190 
191 	for (m = m_min; m <= m_max; ++m) {
192 		unsigned long fpfd;
193 		unsigned int n_min;
194 		unsigned int n_max;
195 		unsigned int n;
196 
197 		/*
198 		 * The VCO operating range is 900 Mhz to 1800 MHz, which limits
199 		 * the allowed values for the multiplier N (normal range
200 		 * 60-120).
201 		 *
202 		 * Fvco = Fin * N / M
203 		 */
204 		fpfd = fin / m;
205 		n_min = max_t(unsigned int, 60, DIV_ROUND_UP(900000000, fpfd));
206 		n_max = min_t(unsigned int, 120, 1800000000 / fpfd);
207 
208 		for (n = n_min; n < n_max; ++n) {
209 			unsigned long fvco;
210 			unsigned int e_min;
211 			unsigned int e;
212 
213 			/*
214 			 * The output frequency is limited to 1039.5 MHz,
215 			 * limiting again the allowed values for the
216 			 * post-divider E (normal value 1, 2 or 4).
217 			 *
218 			 * Fout = Fvco / E
219 			 */
220 			fvco = fpfd * n;
221 			e_min = fvco > 1039500000 ? 1 : 0;
222 
223 			for (e = e_min; e < 3; ++e) {
224 				unsigned long fout;
225 				unsigned long diff;
226 				unsigned int div;
227 
228 				/*
229 				 * Finally we have a programable divider after
230 				 * the PLL, followed by a an optional fixed /7
231 				 * divider.
232 				 */
233 				fout = fvco / (1 << e) / div7;
234 				div = max(1UL, DIV_ROUND_CLOSEST(fout, target));
235 				diff = abs(fout / div - target);
236 
237 				if (diff < pll->diff) {
238 					pll->diff = diff;
239 					pll->pll_m = m;
240 					pll->pll_n = n;
241 					pll->pll_e = e;
242 					pll->div = div;
243 					pll->clksel = clksel;
244 
245 					if (diff == 0)
246 						goto done;
247 				}
248 			}
249 		}
250 	}
251 
252 done:
253 	output = fin * pll->pll_n / pll->pll_m / (1 << pll->pll_e)
254 	       / div7 / pll->div;
255 	error = (long)(output - target) * 10000 / (long)target;
256 
257 	dev_dbg(lvds->dev,
258 		"%pC %lu Hz -> Fout %lu Hz (target %lu Hz, error %d.%02u%%), PLL M/N/E/DIV %u/%u/%u/%u\n",
259 		clk, fin, output, target, error / 100,
260 		error < 0 ? -error % 100 : error % 100,
261 		pll->pll_m, pll->pll_n, pll->pll_e, pll->div);
262 }
263 
__rcar_lvds_pll_setup_d3_e3(struct rcar_lvds * lvds,unsigned int freq,bool dot_clock_only)264 static void __rcar_lvds_pll_setup_d3_e3(struct rcar_lvds *lvds,
265 					unsigned int freq, bool dot_clock_only)
266 {
267 	struct pll_info pll = { .diff = (unsigned long)-1 };
268 	u32 lvdpllcr;
269 
270 	rcar_lvds_d3_e3_pll_calc(lvds, lvds->clocks.dotclkin[0], freq, &pll,
271 				 LVDPLLCR_CKSEL_DU_DOTCLKIN(0), dot_clock_only);
272 	rcar_lvds_d3_e3_pll_calc(lvds, lvds->clocks.dotclkin[1], freq, &pll,
273 				 LVDPLLCR_CKSEL_DU_DOTCLKIN(1), dot_clock_only);
274 	rcar_lvds_d3_e3_pll_calc(lvds, lvds->clocks.extal, freq, &pll,
275 				 LVDPLLCR_CKSEL_EXTAL, dot_clock_only);
276 
277 	lvdpllcr = LVDPLLCR_PLLON | pll.clksel | LVDPLLCR_CLKOUT
278 		 | LVDPLLCR_PLLN(pll.pll_n - 1) | LVDPLLCR_PLLM(pll.pll_m - 1);
279 
280 	if (pll.pll_e > 0)
281 		lvdpllcr |= LVDPLLCR_STP_CLKOUTE | LVDPLLCR_OUTCLKSEL
282 			 |  LVDPLLCR_PLLE(pll.pll_e - 1);
283 
284 	if (dot_clock_only)
285 		lvdpllcr |= LVDPLLCR_OCKSEL;
286 
287 	rcar_lvds_write(lvds, LVDPLLCR, lvdpllcr);
288 
289 	if (pll.div > 1)
290 		/*
291 		 * The DIVRESET bit is a misnomer, setting it to 1 deasserts the
292 		 * divisor reset.
293 		 */
294 		rcar_lvds_write(lvds, LVDDIV, LVDDIV_DIVSEL |
295 				LVDDIV_DIVRESET | LVDDIV_DIV(pll.div - 1));
296 	else
297 		rcar_lvds_write(lvds, LVDDIV, 0);
298 }
299 
rcar_lvds_pll_setup_d3_e3(struct rcar_lvds * lvds,unsigned int freq)300 static void rcar_lvds_pll_setup_d3_e3(struct rcar_lvds *lvds, unsigned int freq)
301 {
302 	__rcar_lvds_pll_setup_d3_e3(lvds, freq, false);
303 }
304 
305 /* -----------------------------------------------------------------------------
306  * Clock - D3/E3 only
307  */
308 
rcar_lvds_pclk_enable(struct drm_bridge * bridge,unsigned long freq)309 int rcar_lvds_pclk_enable(struct drm_bridge *bridge, unsigned long freq)
310 {
311 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
312 	int ret;
313 
314 	if (WARN_ON(!(lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL)))
315 		return -ENODEV;
316 
317 	dev_dbg(lvds->dev, "enabling LVDS PLL, freq=%luHz\n", freq);
318 
319 	ret = clk_prepare_enable(lvds->clocks.mod);
320 	if (ret < 0)
321 		return ret;
322 
323 	__rcar_lvds_pll_setup_d3_e3(lvds, freq, true);
324 
325 	return 0;
326 }
327 EXPORT_SYMBOL_GPL(rcar_lvds_pclk_enable);
328 
rcar_lvds_pclk_disable(struct drm_bridge * bridge)329 void rcar_lvds_pclk_disable(struct drm_bridge *bridge)
330 {
331 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
332 
333 	if (WARN_ON(!(lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL)))
334 		return;
335 
336 	dev_dbg(lvds->dev, "disabling LVDS PLL\n");
337 
338 	rcar_lvds_write(lvds, LVDPLLCR, 0);
339 
340 	clk_disable_unprepare(lvds->clocks.mod);
341 }
342 EXPORT_SYMBOL_GPL(rcar_lvds_pclk_disable);
343 
344 /* -----------------------------------------------------------------------------
345  * Bridge
346  */
347 
rcar_lvds_get_lvds_mode(struct rcar_lvds * lvds,const struct drm_connector * connector)348 static enum rcar_lvds_mode rcar_lvds_get_lvds_mode(struct rcar_lvds *lvds,
349 					const struct drm_connector *connector)
350 {
351 	const struct drm_display_info *info;
352 	enum rcar_lvds_mode mode;
353 
354 	/*
355 	 * There is no API yet to retrieve LVDS mode from a bridge, only panels
356 	 * are supported.
357 	 */
358 	if (!lvds->panel)
359 		return RCAR_LVDS_MODE_JEIDA;
360 
361 	info = &connector->display_info;
362 	if (!info->num_bus_formats || !info->bus_formats) {
363 		dev_warn(lvds->dev,
364 			 "no LVDS bus format reported, using JEIDA\n");
365 		return RCAR_LVDS_MODE_JEIDA;
366 	}
367 
368 	switch (info->bus_formats[0]) {
369 	case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
370 	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
371 		mode = RCAR_LVDS_MODE_JEIDA;
372 		break;
373 	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
374 		mode = RCAR_LVDS_MODE_VESA;
375 		break;
376 	default:
377 		dev_warn(lvds->dev,
378 			 "unsupported LVDS bus format 0x%04x, using JEIDA\n",
379 			 info->bus_formats[0]);
380 		return RCAR_LVDS_MODE_JEIDA;
381 	}
382 
383 	if (info->bus_flags & DRM_BUS_FLAG_DATA_LSB_TO_MSB)
384 		mode |= RCAR_LVDS_MODE_MIRROR;
385 
386 	return mode;
387 }
388 
__rcar_lvds_atomic_enable(struct drm_bridge * bridge,struct drm_atomic_state * state,struct drm_crtc * crtc,struct drm_connector * connector)389 static void __rcar_lvds_atomic_enable(struct drm_bridge *bridge,
390 				      struct drm_atomic_state *state,
391 				      struct drm_crtc *crtc,
392 				      struct drm_connector *connector)
393 {
394 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
395 	u32 lvdhcr;
396 	u32 lvdcr0;
397 	int ret;
398 
399 	ret = clk_prepare_enable(lvds->clocks.mod);
400 	if (ret < 0)
401 		return;
402 
403 	/* Enable the companion LVDS encoder in dual-link mode. */
404 	if (lvds->link_type != RCAR_LVDS_SINGLE_LINK && lvds->companion)
405 		__rcar_lvds_atomic_enable(lvds->companion, state, crtc,
406 					  connector);
407 
408 	/*
409 	 * Hardcode the channels and control signals routing for now.
410 	 *
411 	 * HSYNC -> CTRL0
412 	 * VSYNC -> CTRL1
413 	 * DISP  -> CTRL2
414 	 * 0     -> CTRL3
415 	 */
416 	rcar_lvds_write(lvds, LVDCTRCR, LVDCTRCR_CTR3SEL_ZERO |
417 			LVDCTRCR_CTR2SEL_DISP | LVDCTRCR_CTR1SEL_VSYNC |
418 			LVDCTRCR_CTR0SEL_HSYNC);
419 
420 	if (lvds->info->quirks & RCAR_LVDS_QUIRK_LANES)
421 		lvdhcr = LVDCHCR_CHSEL_CH(0, 0) | LVDCHCR_CHSEL_CH(1, 3)
422 		       | LVDCHCR_CHSEL_CH(2, 2) | LVDCHCR_CHSEL_CH(3, 1);
423 	else
424 		lvdhcr = LVDCHCR_CHSEL_CH(0, 0) | LVDCHCR_CHSEL_CH(1, 1)
425 		       | LVDCHCR_CHSEL_CH(2, 2) | LVDCHCR_CHSEL_CH(3, 3);
426 
427 	rcar_lvds_write(lvds, LVDCHCR, lvdhcr);
428 
429 	if (lvds->info->quirks & RCAR_LVDS_QUIRK_DUAL_LINK) {
430 		u32 lvdstripe = 0;
431 
432 		if (lvds->link_type != RCAR_LVDS_SINGLE_LINK) {
433 			/*
434 			 * By default we generate even pixels from the primary
435 			 * encoder and odd pixels from the companion encoder.
436 			 * Swap pixels around if the sink requires odd pixels
437 			 * from the primary encoder and even pixels from the
438 			 * companion encoder.
439 			 */
440 			bool swap_pixels = lvds->link_type ==
441 				RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS;
442 
443 			/*
444 			 * Configure vertical stripe since we are dealing with
445 			 * an LVDS dual-link connection.
446 			 *
447 			 * ST_SWAP is reserved for the companion encoder, only
448 			 * set it in the primary encoder.
449 			 */
450 			lvdstripe = LVDSTRIPE_ST_ON
451 				  | (lvds->companion && swap_pixels ?
452 				     LVDSTRIPE_ST_SWAP : 0);
453 		}
454 		rcar_lvds_write(lvds, LVDSTRIPE, lvdstripe);
455 	}
456 
457 	/*
458 	 * PLL clock configuration on all instances but the companion in
459 	 * dual-link mode.
460 	 */
461 	if (lvds->link_type == RCAR_LVDS_SINGLE_LINK || lvds->companion) {
462 		const struct drm_crtc_state *crtc_state =
463 			drm_atomic_get_new_crtc_state(state, crtc);
464 		const struct drm_display_mode *mode =
465 			&crtc_state->adjusted_mode;
466 
467 		lvds->info->pll_setup(lvds, mode->clock * 1000);
468 	}
469 
470 	/* Set the LVDS mode and select the input. */
471 	lvdcr0 = rcar_lvds_get_lvds_mode(lvds, connector) << LVDCR0_LVMD_SHIFT;
472 
473 	if (lvds->bridge.encoder) {
474 		if (drm_crtc_index(crtc) == 2)
475 			lvdcr0 |= LVDCR0_DUSEL;
476 	}
477 
478 	rcar_lvds_write(lvds, LVDCR0, lvdcr0);
479 
480 	/* Turn all the channels on. */
481 	rcar_lvds_write(lvds, LVDCR1,
482 			LVDCR1_CHSTBY(3) | LVDCR1_CHSTBY(2) |
483 			LVDCR1_CHSTBY(1) | LVDCR1_CHSTBY(0) | LVDCR1_CLKSTBY);
484 
485 	if (lvds->info->gen < 3) {
486 		/* Enable LVDS operation and turn the bias circuitry on. */
487 		lvdcr0 |= LVDCR0_BEN | LVDCR0_LVEN;
488 		rcar_lvds_write(lvds, LVDCR0, lvdcr0);
489 	}
490 
491 	if (!(lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL)) {
492 		/*
493 		 * Turn the PLL on (simple PLL only, extended PLL is fully
494 		 * controlled through LVDPLLCR).
495 		 */
496 		lvdcr0 |= LVDCR0_PLLON;
497 		rcar_lvds_write(lvds, LVDCR0, lvdcr0);
498 	}
499 
500 	if (lvds->info->quirks & RCAR_LVDS_QUIRK_PWD) {
501 		/* Set LVDS normal mode. */
502 		lvdcr0 |= LVDCR0_PWD;
503 		rcar_lvds_write(lvds, LVDCR0, lvdcr0);
504 	}
505 
506 	if (lvds->info->quirks & RCAR_LVDS_QUIRK_GEN3_LVEN) {
507 		/*
508 		 * Turn on the LVDS PHY. On D3, the LVEN and LVRES bit must be
509 		 * set at the same time, so don't write the register yet.
510 		 */
511 		lvdcr0 |= LVDCR0_LVEN;
512 		if (!(lvds->info->quirks & RCAR_LVDS_QUIRK_PWD))
513 			rcar_lvds_write(lvds, LVDCR0, lvdcr0);
514 	}
515 
516 	if (!(lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL)) {
517 		/* Wait for the PLL startup delay (simple PLL only). */
518 		usleep_range(100, 150);
519 	}
520 
521 	/* Turn the output on. */
522 	lvdcr0 |= LVDCR0_LVRES;
523 	rcar_lvds_write(lvds, LVDCR0, lvdcr0);
524 }
525 
rcar_lvds_atomic_enable(struct drm_bridge * bridge,struct drm_bridge_state * old_bridge_state)526 static void rcar_lvds_atomic_enable(struct drm_bridge *bridge,
527 				    struct drm_bridge_state *old_bridge_state)
528 {
529 	struct drm_atomic_state *state = old_bridge_state->base.state;
530 	struct drm_connector *connector;
531 	struct drm_crtc *crtc;
532 
533 	connector = drm_atomic_get_new_connector_for_encoder(state,
534 							     bridge->encoder);
535 	crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
536 
537 	__rcar_lvds_atomic_enable(bridge, state, crtc, connector);
538 }
539 
rcar_lvds_atomic_disable(struct drm_bridge * bridge,struct drm_bridge_state * old_bridge_state)540 static void rcar_lvds_atomic_disable(struct drm_bridge *bridge,
541 				     struct drm_bridge_state *old_bridge_state)
542 {
543 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
544 
545 	rcar_lvds_write(lvds, LVDCR0, 0);
546 	rcar_lvds_write(lvds, LVDCR1, 0);
547 	rcar_lvds_write(lvds, LVDPLLCR, 0);
548 
549 	/* Disable the companion LVDS encoder in dual-link mode. */
550 	if (lvds->link_type != RCAR_LVDS_SINGLE_LINK && lvds->companion)
551 		lvds->companion->funcs->atomic_disable(lvds->companion,
552 						       old_bridge_state);
553 
554 	clk_disable_unprepare(lvds->clocks.mod);
555 }
556 
rcar_lvds_mode_fixup(struct drm_bridge * bridge,const struct drm_display_mode * mode,struct drm_display_mode * adjusted_mode)557 static bool rcar_lvds_mode_fixup(struct drm_bridge *bridge,
558 				 const struct drm_display_mode *mode,
559 				 struct drm_display_mode *adjusted_mode)
560 {
561 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
562 	int min_freq;
563 
564 	/*
565 	 * The internal LVDS encoder has a restricted clock frequency operating
566 	 * range, from 5MHz to 148.5MHz on D3 and E3, and from 31MHz to
567 	 * 148.5MHz on all other platforms. Clamp the clock accordingly.
568 	 */
569 	min_freq = lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL ? 5000 : 31000;
570 	adjusted_mode->clock = clamp(adjusted_mode->clock, min_freq, 148500);
571 
572 	return true;
573 }
574 
rcar_lvds_attach(struct drm_bridge * bridge,enum drm_bridge_attach_flags flags)575 static int rcar_lvds_attach(struct drm_bridge *bridge,
576 			    enum drm_bridge_attach_flags flags)
577 {
578 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
579 
580 	if (!lvds->next_bridge)
581 		return 0;
582 
583 	return drm_bridge_attach(bridge->encoder, lvds->next_bridge, bridge,
584 				 flags);
585 }
586 
587 static const struct drm_bridge_funcs rcar_lvds_bridge_ops = {
588 	.attach = rcar_lvds_attach,
589 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
590 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
591 	.atomic_reset = drm_atomic_helper_bridge_reset,
592 	.atomic_enable = rcar_lvds_atomic_enable,
593 	.atomic_disable = rcar_lvds_atomic_disable,
594 	.mode_fixup = rcar_lvds_mode_fixup,
595 };
596 
rcar_lvds_dual_link(struct drm_bridge * bridge)597 bool rcar_lvds_dual_link(struct drm_bridge *bridge)
598 {
599 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
600 
601 	return lvds->link_type != RCAR_LVDS_SINGLE_LINK;
602 }
603 EXPORT_SYMBOL_GPL(rcar_lvds_dual_link);
604 
rcar_lvds_is_connected(struct drm_bridge * bridge)605 bool rcar_lvds_is_connected(struct drm_bridge *bridge)
606 {
607 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
608 
609 	return lvds->next_bridge != NULL;
610 }
611 EXPORT_SYMBOL_GPL(rcar_lvds_is_connected);
612 
613 /* -----------------------------------------------------------------------------
614  * Probe & Remove
615  */
616 
rcar_lvds_parse_dt_companion(struct rcar_lvds * lvds)617 static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
618 {
619 	const struct of_device_id *match;
620 	struct device_node *companion;
621 	struct device_node *port0, *port1;
622 	struct rcar_lvds *companion_lvds;
623 	struct device *dev = lvds->dev;
624 	int dual_link;
625 	int ret = 0;
626 
627 	/* Locate the companion LVDS encoder for dual-link operation, if any. */
628 	companion = of_parse_phandle(dev->of_node, "renesas,companion", 0);
629 	if (!companion)
630 		return 0;
631 
632 	/*
633 	 * Sanity check: the companion encoder must have the same compatible
634 	 * string.
635 	 */
636 	match = of_match_device(dev->driver->of_match_table, dev);
637 	if (!of_device_is_compatible(companion, match->compatible)) {
638 		dev_err(dev, "Companion LVDS encoder is invalid\n");
639 		ret = -ENXIO;
640 		goto done;
641 	}
642 
643 	/*
644 	 * We need to work out if the sink is expecting us to function in
645 	 * dual-link mode. We do this by looking at the DT port nodes we are
646 	 * connected to, if they are marked as expecting even pixels and
647 	 * odd pixels than we need to enable vertical stripe output.
648 	 */
649 	port0 = of_graph_get_port_by_id(dev->of_node, 1);
650 	port1 = of_graph_get_port_by_id(companion, 1);
651 	dual_link = drm_of_lvds_get_dual_link_pixel_order(port0, port1);
652 	of_node_put(port0);
653 	of_node_put(port1);
654 
655 	switch (dual_link) {
656 	case DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS:
657 		lvds->link_type = RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS;
658 		break;
659 	case DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS:
660 		lvds->link_type = RCAR_LVDS_DUAL_LINK_EVEN_ODD_PIXELS;
661 		break;
662 	default:
663 		/*
664 		 * Early dual-link bridge specific implementations populate the
665 		 * timings field of drm_bridge. If the flag is set, we assume
666 		 * that we are expected to generate even pixels from the primary
667 		 * encoder, and odd pixels from the companion encoder.
668 		 */
669 		if (lvds->next_bridge->timings &&
670 		    lvds->next_bridge->timings->dual_link)
671 			lvds->link_type = RCAR_LVDS_DUAL_LINK_EVEN_ODD_PIXELS;
672 		else
673 			lvds->link_type = RCAR_LVDS_SINGLE_LINK;
674 	}
675 
676 	if (lvds->link_type == RCAR_LVDS_SINGLE_LINK) {
677 		dev_dbg(dev, "Single-link configuration detected\n");
678 		goto done;
679 	}
680 
681 	lvds->companion = of_drm_find_bridge(companion);
682 	if (!lvds->companion) {
683 		ret = -EPROBE_DEFER;
684 		goto done;
685 	}
686 
687 	dev_dbg(dev,
688 		"Dual-link configuration detected (companion encoder %pOF)\n",
689 		companion);
690 
691 	if (lvds->link_type == RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS)
692 		dev_dbg(dev, "Data swapping required\n");
693 
694 	/*
695 	 * FIXME: We should not be messing with the companion encoder private
696 	 * data from the primary encoder, we should rather let the companion
697 	 * encoder work things out on its own. However, the companion encoder
698 	 * doesn't hold a reference to the primary encoder, and
699 	 * drm_of_lvds_get_dual_link_pixel_order needs to be given references
700 	 * to the output ports of both encoders, therefore leave it like this
701 	 * for the time being.
702 	 */
703 	companion_lvds = bridge_to_rcar_lvds(lvds->companion);
704 	companion_lvds->link_type = lvds->link_type;
705 
706 done:
707 	of_node_put(companion);
708 
709 	return ret;
710 }
711 
rcar_lvds_parse_dt(struct rcar_lvds * lvds)712 static int rcar_lvds_parse_dt(struct rcar_lvds *lvds)
713 {
714 	int ret;
715 
716 	ret = drm_of_find_panel_or_bridge(lvds->dev->of_node, 1, 0,
717 					  &lvds->panel, &lvds->next_bridge);
718 	if (ret)
719 		goto done;
720 
721 	if (lvds->panel) {
722 		lvds->next_bridge = devm_drm_panel_bridge_add(lvds->dev,
723 							      lvds->panel);
724 		if (IS_ERR_OR_NULL(lvds->next_bridge)) {
725 			ret = -EINVAL;
726 			goto done;
727 		}
728 	}
729 
730 	if (lvds->info->quirks & RCAR_LVDS_QUIRK_DUAL_LINK)
731 		ret = rcar_lvds_parse_dt_companion(lvds);
732 
733 done:
734 	/*
735 	 * On D3/E3 the LVDS encoder provides a clock to the DU, which can be
736 	 * used for the DPAD output even when the LVDS output is not connected.
737 	 * Don't fail probe in that case as the DU will need the bridge to
738 	 * control the clock.
739 	 */
740 	if (lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL)
741 		return ret == -ENODEV ? 0 : ret;
742 
743 	return ret;
744 }
745 
rcar_lvds_get_clock(struct rcar_lvds * lvds,const char * name,bool optional)746 static struct clk *rcar_lvds_get_clock(struct rcar_lvds *lvds, const char *name,
747 				       bool optional)
748 {
749 	struct clk *clk;
750 
751 	clk = devm_clk_get(lvds->dev, name);
752 	if (!IS_ERR(clk))
753 		return clk;
754 
755 	if (PTR_ERR(clk) == -ENOENT && optional)
756 		return NULL;
757 
758 	dev_err_probe(lvds->dev, PTR_ERR(clk), "failed to get %s clock\n",
759 		      name ? name : "module");
760 
761 	return clk;
762 }
763 
rcar_lvds_get_clocks(struct rcar_lvds * lvds)764 static int rcar_lvds_get_clocks(struct rcar_lvds *lvds)
765 {
766 	lvds->clocks.mod = rcar_lvds_get_clock(lvds, NULL, false);
767 	if (IS_ERR(lvds->clocks.mod))
768 		return PTR_ERR(lvds->clocks.mod);
769 
770 	/*
771 	 * LVDS encoders without an extended PLL have no external clock inputs.
772 	 */
773 	if (!(lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL))
774 		return 0;
775 
776 	lvds->clocks.extal = rcar_lvds_get_clock(lvds, "extal", true);
777 	if (IS_ERR(lvds->clocks.extal))
778 		return PTR_ERR(lvds->clocks.extal);
779 
780 	lvds->clocks.dotclkin[0] = rcar_lvds_get_clock(lvds, "dclkin.0", true);
781 	if (IS_ERR(lvds->clocks.dotclkin[0]))
782 		return PTR_ERR(lvds->clocks.dotclkin[0]);
783 
784 	lvds->clocks.dotclkin[1] = rcar_lvds_get_clock(lvds, "dclkin.1", true);
785 	if (IS_ERR(lvds->clocks.dotclkin[1]))
786 		return PTR_ERR(lvds->clocks.dotclkin[1]);
787 
788 	/* At least one input to the PLL must be available. */
789 	if (!lvds->clocks.extal && !lvds->clocks.dotclkin[0] &&
790 	    !lvds->clocks.dotclkin[1]) {
791 		dev_err(lvds->dev,
792 			"no input clock (extal, dclkin.0 or dclkin.1)\n");
793 		return -EINVAL;
794 	}
795 
796 	return 0;
797 }
798 
799 static const struct rcar_lvds_device_info rcar_lvds_r8a7790es1_info = {
800 	.gen = 2,
801 	.quirks = RCAR_LVDS_QUIRK_LANES,
802 	.pll_setup = rcar_lvds_pll_setup_gen2,
803 };
804 
805 static const struct soc_device_attribute lvds_quirk_matches[] = {
806 	{
807 		.soc_id = "r8a7790", .revision = "ES1.*",
808 		.data = &rcar_lvds_r8a7790es1_info,
809 	},
810 	{ /* sentinel */ }
811 };
812 
rcar_lvds_probe(struct platform_device * pdev)813 static int rcar_lvds_probe(struct platform_device *pdev)
814 {
815 	const struct soc_device_attribute *attr;
816 	struct rcar_lvds *lvds;
817 	int ret;
818 
819 	lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
820 	if (lvds == NULL)
821 		return -ENOMEM;
822 
823 	platform_set_drvdata(pdev, lvds);
824 
825 	lvds->dev = &pdev->dev;
826 	lvds->info = of_device_get_match_data(&pdev->dev);
827 
828 	attr = soc_device_match(lvds_quirk_matches);
829 	if (attr)
830 		lvds->info = attr->data;
831 
832 	ret = rcar_lvds_parse_dt(lvds);
833 	if (ret < 0)
834 		return ret;
835 
836 	lvds->bridge.funcs = &rcar_lvds_bridge_ops;
837 	lvds->bridge.of_node = pdev->dev.of_node;
838 
839 	lvds->mmio = devm_platform_ioremap_resource(pdev, 0);
840 	if (IS_ERR(lvds->mmio))
841 		return PTR_ERR(lvds->mmio);
842 
843 	ret = rcar_lvds_get_clocks(lvds);
844 	if (ret < 0)
845 		return ret;
846 
847 	drm_bridge_add(&lvds->bridge);
848 
849 	return 0;
850 }
851 
rcar_lvds_remove(struct platform_device * pdev)852 static int rcar_lvds_remove(struct platform_device *pdev)
853 {
854 	struct rcar_lvds *lvds = platform_get_drvdata(pdev);
855 
856 	drm_bridge_remove(&lvds->bridge);
857 
858 	return 0;
859 }
860 
861 static const struct rcar_lvds_device_info rcar_lvds_gen2_info = {
862 	.gen = 2,
863 	.pll_setup = rcar_lvds_pll_setup_gen2,
864 };
865 
866 static const struct rcar_lvds_device_info rcar_lvds_gen3_info = {
867 	.gen = 3,
868 	.quirks = RCAR_LVDS_QUIRK_PWD,
869 	.pll_setup = rcar_lvds_pll_setup_gen3,
870 };
871 
872 static const struct rcar_lvds_device_info rcar_lvds_r8a77970_info = {
873 	.gen = 3,
874 	.quirks = RCAR_LVDS_QUIRK_PWD | RCAR_LVDS_QUIRK_GEN3_LVEN,
875 	.pll_setup = rcar_lvds_pll_setup_gen2,
876 };
877 
878 static const struct rcar_lvds_device_info rcar_lvds_r8a77990_info = {
879 	.gen = 3,
880 	.quirks = RCAR_LVDS_QUIRK_GEN3_LVEN | RCAR_LVDS_QUIRK_EXT_PLL
881 		| RCAR_LVDS_QUIRK_DUAL_LINK,
882 	.pll_setup = rcar_lvds_pll_setup_d3_e3,
883 };
884 
885 static const struct rcar_lvds_device_info rcar_lvds_r8a77995_info = {
886 	.gen = 3,
887 	.quirks = RCAR_LVDS_QUIRK_GEN3_LVEN | RCAR_LVDS_QUIRK_PWD
888 		| RCAR_LVDS_QUIRK_EXT_PLL | RCAR_LVDS_QUIRK_DUAL_LINK,
889 	.pll_setup = rcar_lvds_pll_setup_d3_e3,
890 };
891 
892 static const struct of_device_id rcar_lvds_of_table[] = {
893 	{ .compatible = "renesas,r8a7742-lvds", .data = &rcar_lvds_gen2_info },
894 	{ .compatible = "renesas,r8a7743-lvds", .data = &rcar_lvds_gen2_info },
895 	{ .compatible = "renesas,r8a7744-lvds", .data = &rcar_lvds_gen2_info },
896 	{ .compatible = "renesas,r8a774a1-lvds", .data = &rcar_lvds_gen3_info },
897 	{ .compatible = "renesas,r8a774b1-lvds", .data = &rcar_lvds_gen3_info },
898 	{ .compatible = "renesas,r8a774c0-lvds", .data = &rcar_lvds_r8a77990_info },
899 	{ .compatible = "renesas,r8a774e1-lvds", .data = &rcar_lvds_gen3_info },
900 	{ .compatible = "renesas,r8a7790-lvds", .data = &rcar_lvds_gen2_info },
901 	{ .compatible = "renesas,r8a7791-lvds", .data = &rcar_lvds_gen2_info },
902 	{ .compatible = "renesas,r8a7793-lvds", .data = &rcar_lvds_gen2_info },
903 	{ .compatible = "renesas,r8a7795-lvds", .data = &rcar_lvds_gen3_info },
904 	{ .compatible = "renesas,r8a7796-lvds", .data = &rcar_lvds_gen3_info },
905 	{ .compatible = "renesas,r8a77961-lvds", .data = &rcar_lvds_gen3_info },
906 	{ .compatible = "renesas,r8a77965-lvds", .data = &rcar_lvds_gen3_info },
907 	{ .compatible = "renesas,r8a77970-lvds", .data = &rcar_lvds_r8a77970_info },
908 	{ .compatible = "renesas,r8a77980-lvds", .data = &rcar_lvds_gen3_info },
909 	{ .compatible = "renesas,r8a77990-lvds", .data = &rcar_lvds_r8a77990_info },
910 	{ .compatible = "renesas,r8a77995-lvds", .data = &rcar_lvds_r8a77995_info },
911 	{ }
912 };
913 
914 MODULE_DEVICE_TABLE(of, rcar_lvds_of_table);
915 
916 static struct platform_driver rcar_lvds_platform_driver = {
917 	.probe		= rcar_lvds_probe,
918 	.remove		= rcar_lvds_remove,
919 	.driver		= {
920 		.name	= "rcar-lvds",
921 		.of_match_table = rcar_lvds_of_table,
922 	},
923 };
924 
925 module_platform_driver(rcar_lvds_platform_driver);
926 
927 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
928 MODULE_DESCRIPTION("Renesas R-Car LVDS Encoder Driver");
929 MODULE_LICENSE("GPL");
930