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