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 
20 #include <drm/drm_atomic.h>
21 #include <drm/drm_atomic_helper.h>
22 #include <drm/drm_bridge.h>
23 #include <drm/drm_panel.h>
24 #include <drm/drm_probe_helper.h>
25 
26 #include "rcar_lvds.h"
27 #include "rcar_lvds_regs.h"
28 
29 struct rcar_lvds;
30 
31 /* Keep in sync with the LVDCR0.LVMD hardware register values. */
32 enum rcar_lvds_mode {
33 	RCAR_LVDS_MODE_JEIDA = 0,
34 	RCAR_LVDS_MODE_MIRROR = 1,
35 	RCAR_LVDS_MODE_VESA = 4,
36 };
37 
38 #define RCAR_LVDS_QUIRK_LANES		BIT(0)	/* LVDS lanes 1 and 3 inverted */
39 #define RCAR_LVDS_QUIRK_GEN3_LVEN	BIT(1)	/* LVEN bit needs to be set on R8A77970/R8A7799x */
40 #define RCAR_LVDS_QUIRK_PWD		BIT(2)	/* PWD bit available (all of Gen3 but E3) */
41 #define RCAR_LVDS_QUIRK_EXT_PLL		BIT(3)	/* Has extended PLL */
42 #define RCAR_LVDS_QUIRK_DUAL_LINK	BIT(4)	/* Supports dual-link operation */
43 
44 struct rcar_lvds_device_info {
45 	unsigned int gen;
46 	unsigned int quirks;
47 	void (*pll_setup)(struct rcar_lvds *lvds, unsigned int freq);
48 };
49 
50 struct rcar_lvds {
51 	struct device *dev;
52 	const struct rcar_lvds_device_info *info;
53 
54 	struct drm_bridge bridge;
55 
56 	struct drm_bridge *next_bridge;
57 	struct drm_connector connector;
58 	struct drm_panel *panel;
59 
60 	void __iomem *mmio;
61 	struct {
62 		struct clk *mod;		/* CPG module clock */
63 		struct clk *extal;		/* External clock */
64 		struct clk *dotclkin[2];	/* External DU clocks */
65 	} clocks;
66 
67 	struct drm_display_mode display_mode;
68 	enum rcar_lvds_mode mode;
69 
70 	struct drm_bridge *companion;
71 	bool dual_link;
72 };
73 
74 #define bridge_to_rcar_lvds(b) \
75 	container_of(b, struct rcar_lvds, bridge)
76 
77 #define connector_to_rcar_lvds(c) \
78 	container_of(c, struct rcar_lvds, connector)
79 
rcar_lvds_write(struct rcar_lvds * lvds,u32 reg,u32 data)80 static void rcar_lvds_write(struct rcar_lvds *lvds, u32 reg, u32 data)
81 {
82 	iowrite32(data, lvds->mmio + reg);
83 }
84 
85 /* -----------------------------------------------------------------------------
86  * Connector & Panel
87  */
88 
rcar_lvds_connector_get_modes(struct drm_connector * connector)89 static int rcar_lvds_connector_get_modes(struct drm_connector *connector)
90 {
91 	struct rcar_lvds *lvds = connector_to_rcar_lvds(connector);
92 
93 	return drm_panel_get_modes(lvds->panel);
94 }
95 
rcar_lvds_connector_atomic_check(struct drm_connector * connector,struct drm_atomic_state * state)96 static int rcar_lvds_connector_atomic_check(struct drm_connector *connector,
97 					    struct drm_atomic_state *state)
98 {
99 	struct rcar_lvds *lvds = connector_to_rcar_lvds(connector);
100 	const struct drm_display_mode *panel_mode;
101 	struct drm_connector_state *conn_state;
102 	struct drm_crtc_state *crtc_state;
103 
104 	conn_state = drm_atomic_get_new_connector_state(state, connector);
105 	if (!conn_state->crtc)
106 		return 0;
107 
108 	if (list_empty(&connector->modes)) {
109 		dev_dbg(lvds->dev, "connector: empty modes list\n");
110 		return -EINVAL;
111 	}
112 
113 	panel_mode = list_first_entry(&connector->modes,
114 				      struct drm_display_mode, head);
115 
116 	/* We're not allowed to modify the resolution. */
117 	crtc_state = drm_atomic_get_crtc_state(state, conn_state->crtc);
118 	if (IS_ERR(crtc_state))
119 		return PTR_ERR(crtc_state);
120 
121 	if (crtc_state->mode.hdisplay != panel_mode->hdisplay ||
122 	    crtc_state->mode.vdisplay != panel_mode->vdisplay)
123 		return -EINVAL;
124 
125 	/* The flat panel mode is fixed, just copy it to the adjusted mode. */
126 	drm_mode_copy(&crtc_state->adjusted_mode, panel_mode);
127 
128 	return 0;
129 }
130 
131 static const struct drm_connector_helper_funcs rcar_lvds_conn_helper_funcs = {
132 	.get_modes = rcar_lvds_connector_get_modes,
133 	.atomic_check = rcar_lvds_connector_atomic_check,
134 };
135 
136 static const struct drm_connector_funcs rcar_lvds_conn_funcs = {
137 	.reset = drm_atomic_helper_connector_reset,
138 	.fill_modes = drm_helper_probe_single_connector_modes,
139 	.destroy = drm_connector_cleanup,
140 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
141 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
142 };
143 
144 /* -----------------------------------------------------------------------------
145  * PLL Setup
146  */
147 
rcar_lvds_pll_setup_gen2(struct rcar_lvds * lvds,unsigned int freq)148 static void rcar_lvds_pll_setup_gen2(struct rcar_lvds *lvds, unsigned int freq)
149 {
150 	u32 val;
151 
152 	if (freq < 39000000)
153 		val = LVDPLLCR_CEEN | LVDPLLCR_COSEL | LVDPLLCR_PLLDLYCNT_38M;
154 	else if (freq < 61000000)
155 		val = LVDPLLCR_CEEN | LVDPLLCR_COSEL | LVDPLLCR_PLLDLYCNT_60M;
156 	else if (freq < 121000000)
157 		val = LVDPLLCR_CEEN | LVDPLLCR_COSEL | LVDPLLCR_PLLDLYCNT_121M;
158 	else
159 		val = LVDPLLCR_PLLDLYCNT_150M;
160 
161 	rcar_lvds_write(lvds, LVDPLLCR, val);
162 }
163 
rcar_lvds_pll_setup_gen3(struct rcar_lvds * lvds,unsigned int freq)164 static void rcar_lvds_pll_setup_gen3(struct rcar_lvds *lvds, unsigned int freq)
165 {
166 	u32 val;
167 
168 	if (freq < 42000000)
169 		val = LVDPLLCR_PLLDIVCNT_42M;
170 	else if (freq < 85000000)
171 		val = LVDPLLCR_PLLDIVCNT_85M;
172 	else if (freq < 128000000)
173 		val = LVDPLLCR_PLLDIVCNT_128M;
174 	else
175 		val = LVDPLLCR_PLLDIVCNT_148M;
176 
177 	rcar_lvds_write(lvds, LVDPLLCR, val);
178 }
179 
180 struct pll_info {
181 	unsigned long diff;
182 	unsigned int pll_m;
183 	unsigned int pll_n;
184 	unsigned int pll_e;
185 	unsigned int div;
186 	u32 clksel;
187 };
188 
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)189 static void rcar_lvds_d3_e3_pll_calc(struct rcar_lvds *lvds, struct clk *clk,
190 				     unsigned long target, struct pll_info *pll,
191 				     u32 clksel, bool dot_clock_only)
192 {
193 	unsigned int div7 = dot_clock_only ? 1 : 7;
194 	unsigned long output;
195 	unsigned long fin;
196 	unsigned int m_min;
197 	unsigned int m_max;
198 	unsigned int m;
199 	int error;
200 
201 	if (!clk)
202 		return;
203 
204 	/*
205 	 * The LVDS PLL is made of a pre-divider and a multiplier (strangely
206 	 * enough called M and N respectively), followed by a post-divider E.
207 	 *
208 	 *         ,-----.         ,-----.     ,-----.         ,-----.
209 	 * Fin --> | 1/M | -Fpdf-> | PFD | --> | VCO | -Fvco-> | 1/E | --> Fout
210 	 *         `-----'     ,-> |     |     `-----'   |     `-----'
211 	 *                     |   `-----'               |
212 	 *                     |         ,-----.         |
213 	 *                     `-------- | 1/N | <-------'
214 	 *                               `-----'
215 	 *
216 	 * The clock output by the PLL is then further divided by a programmable
217 	 * divider DIV to achieve the desired target frequency. Finally, an
218 	 * optional fixed /7 divider is used to convert the bit clock to a pixel
219 	 * clock (as LVDS transmits 7 bits per lane per clock sample).
220 	 *
221 	 *          ,-------.     ,-----.     |\
222 	 * Fout --> | 1/DIV | --> | 1/7 | --> | |
223 	 *          `-------'  |  `-----'     | | --> dot clock
224 	 *                     `------------> | |
225 	 *                                    |/
226 	 *
227 	 * The /7 divider is optional, it is enabled when the LVDS PLL is used
228 	 * to drive the LVDS encoder, and disabled when  used to generate a dot
229 	 * clock for the DU RGB output, without using the LVDS encoder.
230 	 *
231 	 * The PLL allowed input frequency range is 12 MHz to 192 MHz.
232 	 */
233 
234 	fin = clk_get_rate(clk);
235 	if (fin < 12000000 || fin > 192000000)
236 		return;
237 
238 	/*
239 	 * The comparison frequency range is 12 MHz to 24 MHz, which limits the
240 	 * allowed values for the pre-divider M (normal range 1-8).
241 	 *
242 	 * Fpfd = Fin / M
243 	 */
244 	m_min = max_t(unsigned int, 1, DIV_ROUND_UP(fin, 24000000));
245 	m_max = min_t(unsigned int, 8, fin / 12000000);
246 
247 	for (m = m_min; m <= m_max; ++m) {
248 		unsigned long fpfd;
249 		unsigned int n_min;
250 		unsigned int n_max;
251 		unsigned int n;
252 
253 		/*
254 		 * The VCO operating range is 900 Mhz to 1800 MHz, which limits
255 		 * the allowed values for the multiplier N (normal range
256 		 * 60-120).
257 		 *
258 		 * Fvco = Fin * N / M
259 		 */
260 		fpfd = fin / m;
261 		n_min = max_t(unsigned int, 60, DIV_ROUND_UP(900000000, fpfd));
262 		n_max = min_t(unsigned int, 120, 1800000000 / fpfd);
263 
264 		for (n = n_min; n < n_max; ++n) {
265 			unsigned long fvco;
266 			unsigned int e_min;
267 			unsigned int e;
268 
269 			/*
270 			 * The output frequency is limited to 1039.5 MHz,
271 			 * limiting again the allowed values for the
272 			 * post-divider E (normal value 1, 2 or 4).
273 			 *
274 			 * Fout = Fvco / E
275 			 */
276 			fvco = fpfd * n;
277 			e_min = fvco > 1039500000 ? 1 : 0;
278 
279 			for (e = e_min; e < 3; ++e) {
280 				unsigned long fout;
281 				unsigned long diff;
282 				unsigned int div;
283 
284 				/*
285 				 * Finally we have a programable divider after
286 				 * the PLL, followed by a an optional fixed /7
287 				 * divider.
288 				 */
289 				fout = fvco / (1 << e) / div7;
290 				div = max(1UL, DIV_ROUND_CLOSEST(fout, target));
291 				diff = abs(fout / div - target);
292 
293 				if (diff < pll->diff) {
294 					pll->diff = diff;
295 					pll->pll_m = m;
296 					pll->pll_n = n;
297 					pll->pll_e = e;
298 					pll->div = div;
299 					pll->clksel = clksel;
300 
301 					if (diff == 0)
302 						goto done;
303 				}
304 			}
305 		}
306 	}
307 
308 done:
309 	output = fin * pll->pll_n / pll->pll_m / (1 << pll->pll_e)
310 	       / div7 / pll->div;
311 	error = (long)(output - target) * 10000 / (long)target;
312 
313 	dev_dbg(lvds->dev,
314 		"%pC %lu Hz -> Fout %lu Hz (target %lu Hz, error %d.%02u%%), PLL M/N/E/DIV %u/%u/%u/%u\n",
315 		clk, fin, output, target, error / 100,
316 		error < 0 ? -error % 100 : error % 100,
317 		pll->pll_m, pll->pll_n, pll->pll_e, pll->div);
318 }
319 
__rcar_lvds_pll_setup_d3_e3(struct rcar_lvds * lvds,unsigned int freq,bool dot_clock_only)320 static void __rcar_lvds_pll_setup_d3_e3(struct rcar_lvds *lvds,
321 					unsigned int freq, bool dot_clock_only)
322 {
323 	struct pll_info pll = { .diff = (unsigned long)-1 };
324 	u32 lvdpllcr;
325 
326 	rcar_lvds_d3_e3_pll_calc(lvds, lvds->clocks.dotclkin[0], freq, &pll,
327 				 LVDPLLCR_CKSEL_DU_DOTCLKIN(0), dot_clock_only);
328 	rcar_lvds_d3_e3_pll_calc(lvds, lvds->clocks.dotclkin[1], freq, &pll,
329 				 LVDPLLCR_CKSEL_DU_DOTCLKIN(1), dot_clock_only);
330 	rcar_lvds_d3_e3_pll_calc(lvds, lvds->clocks.extal, freq, &pll,
331 				 LVDPLLCR_CKSEL_EXTAL, dot_clock_only);
332 
333 	lvdpllcr = LVDPLLCR_PLLON | pll.clksel | LVDPLLCR_CLKOUT
334 		 | LVDPLLCR_PLLN(pll.pll_n - 1) | LVDPLLCR_PLLM(pll.pll_m - 1);
335 
336 	if (pll.pll_e > 0)
337 		lvdpllcr |= LVDPLLCR_STP_CLKOUTE | LVDPLLCR_OUTCLKSEL
338 			 |  LVDPLLCR_PLLE(pll.pll_e - 1);
339 
340 	if (dot_clock_only)
341 		lvdpllcr |= LVDPLLCR_OCKSEL;
342 
343 	rcar_lvds_write(lvds, LVDPLLCR, lvdpllcr);
344 
345 	if (pll.div > 1)
346 		/*
347 		 * The DIVRESET bit is a misnomer, setting it to 1 deasserts the
348 		 * divisor reset.
349 		 */
350 		rcar_lvds_write(lvds, LVDDIV, LVDDIV_DIVSEL |
351 				LVDDIV_DIVRESET | LVDDIV_DIV(pll.div - 1));
352 	else
353 		rcar_lvds_write(lvds, LVDDIV, 0);
354 }
355 
rcar_lvds_pll_setup_d3_e3(struct rcar_lvds * lvds,unsigned int freq)356 static void rcar_lvds_pll_setup_d3_e3(struct rcar_lvds *lvds, unsigned int freq)
357 {
358 	__rcar_lvds_pll_setup_d3_e3(lvds, freq, false);
359 }
360 
361 /* -----------------------------------------------------------------------------
362  * Clock - D3/E3 only
363  */
364 
rcar_lvds_clk_enable(struct drm_bridge * bridge,unsigned long freq)365 int rcar_lvds_clk_enable(struct drm_bridge *bridge, unsigned long freq)
366 {
367 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
368 	int ret;
369 
370 	if (WARN_ON(!(lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL)))
371 		return -ENODEV;
372 
373 	dev_dbg(lvds->dev, "enabling LVDS PLL, freq=%luHz\n", freq);
374 
375 	ret = clk_prepare_enable(lvds->clocks.mod);
376 	if (ret < 0)
377 		return ret;
378 
379 	__rcar_lvds_pll_setup_d3_e3(lvds, freq, true);
380 
381 	return 0;
382 }
383 EXPORT_SYMBOL_GPL(rcar_lvds_clk_enable);
384 
rcar_lvds_clk_disable(struct drm_bridge * bridge)385 void rcar_lvds_clk_disable(struct drm_bridge *bridge)
386 {
387 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
388 
389 	if (WARN_ON(!(lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL)))
390 		return;
391 
392 	dev_dbg(lvds->dev, "disabling LVDS PLL\n");
393 
394 	rcar_lvds_write(lvds, LVDPLLCR, 0);
395 
396 	clk_disable_unprepare(lvds->clocks.mod);
397 }
398 EXPORT_SYMBOL_GPL(rcar_lvds_clk_disable);
399 
400 /* -----------------------------------------------------------------------------
401  * Bridge
402  */
403 
rcar_lvds_enable(struct drm_bridge * bridge)404 static void rcar_lvds_enable(struct drm_bridge *bridge)
405 {
406 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
407 	const struct drm_display_mode *mode = &lvds->display_mode;
408 	u32 lvdhcr;
409 	u32 lvdcr0;
410 	int ret;
411 
412 	ret = clk_prepare_enable(lvds->clocks.mod);
413 	if (ret < 0)
414 		return;
415 
416 	/* Enable the companion LVDS encoder in dual-link mode. */
417 	if (lvds->dual_link && lvds->companion)
418 		lvds->companion->funcs->enable(lvds->companion);
419 
420 	/*
421 	 * Hardcode the channels and control signals routing for now.
422 	 *
423 	 * HSYNC -> CTRL0
424 	 * VSYNC -> CTRL1
425 	 * DISP  -> CTRL2
426 	 * 0     -> CTRL3
427 	 */
428 	rcar_lvds_write(lvds, LVDCTRCR, LVDCTRCR_CTR3SEL_ZERO |
429 			LVDCTRCR_CTR2SEL_DISP | LVDCTRCR_CTR1SEL_VSYNC |
430 			LVDCTRCR_CTR0SEL_HSYNC);
431 
432 	if (lvds->info->quirks & RCAR_LVDS_QUIRK_LANES)
433 		lvdhcr = LVDCHCR_CHSEL_CH(0, 0) | LVDCHCR_CHSEL_CH(1, 3)
434 		       | LVDCHCR_CHSEL_CH(2, 2) | LVDCHCR_CHSEL_CH(3, 1);
435 	else
436 		lvdhcr = LVDCHCR_CHSEL_CH(0, 0) | LVDCHCR_CHSEL_CH(1, 1)
437 		       | LVDCHCR_CHSEL_CH(2, 2) | LVDCHCR_CHSEL_CH(3, 3);
438 
439 	rcar_lvds_write(lvds, LVDCHCR, lvdhcr);
440 
441 	if (lvds->info->quirks & RCAR_LVDS_QUIRK_DUAL_LINK) {
442 		/*
443 		 * Configure vertical stripe based on the mode of operation of
444 		 * the connected device.
445 		 */
446 		rcar_lvds_write(lvds, LVDSTRIPE,
447 				lvds->dual_link ? LVDSTRIPE_ST_ON : 0);
448 	}
449 
450 	/*
451 	 * PLL clock configuration on all instances but the companion in
452 	 * dual-link mode.
453 	 */
454 	if (!lvds->dual_link || lvds->companion)
455 		lvds->info->pll_setup(lvds, mode->clock * 1000);
456 
457 	/* Set the LVDS mode and select the input. */
458 	lvdcr0 = lvds->mode << LVDCR0_LVMD_SHIFT;
459 
460 	if (lvds->bridge.encoder) {
461 		/*
462 		 * FIXME: We should really retrieve the CRTC through the state,
463 		 * but how do we get a state pointer?
464 		 */
465 		if (drm_crtc_index(lvds->bridge.encoder->crtc) == 2)
466 			lvdcr0 |= LVDCR0_DUSEL;
467 	}
468 
469 	rcar_lvds_write(lvds, LVDCR0, lvdcr0);
470 
471 	/* Turn all the channels on. */
472 	rcar_lvds_write(lvds, LVDCR1,
473 			LVDCR1_CHSTBY(3) | LVDCR1_CHSTBY(2) |
474 			LVDCR1_CHSTBY(1) | LVDCR1_CHSTBY(0) | LVDCR1_CLKSTBY);
475 
476 	if (lvds->info->gen < 3) {
477 		/* Enable LVDS operation and turn the bias circuitry on. */
478 		lvdcr0 |= LVDCR0_BEN | LVDCR0_LVEN;
479 		rcar_lvds_write(lvds, LVDCR0, lvdcr0);
480 	}
481 
482 	if (!(lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL)) {
483 		/*
484 		 * Turn the PLL on (simple PLL only, extended PLL is fully
485 		 * controlled through LVDPLLCR).
486 		 */
487 		lvdcr0 |= LVDCR0_PLLON;
488 		rcar_lvds_write(lvds, LVDCR0, lvdcr0);
489 	}
490 
491 	if (lvds->info->quirks & RCAR_LVDS_QUIRK_PWD) {
492 		/* Set LVDS normal mode. */
493 		lvdcr0 |= LVDCR0_PWD;
494 		rcar_lvds_write(lvds, LVDCR0, lvdcr0);
495 	}
496 
497 	if (lvds->info->quirks & RCAR_LVDS_QUIRK_GEN3_LVEN) {
498 		/*
499 		 * Turn on the LVDS PHY. On D3, the LVEN and LVRES bit must be
500 		 * set at the same time, so don't write the register yet.
501 		 */
502 		lvdcr0 |= LVDCR0_LVEN;
503 		if (!(lvds->info->quirks & RCAR_LVDS_QUIRK_PWD))
504 			rcar_lvds_write(lvds, LVDCR0, lvdcr0);
505 	}
506 
507 	if (!(lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL)) {
508 		/* Wait for the PLL startup delay (simple PLL only). */
509 		usleep_range(100, 150);
510 	}
511 
512 	/* Turn the output on. */
513 	lvdcr0 |= LVDCR0_LVRES;
514 	rcar_lvds_write(lvds, LVDCR0, lvdcr0);
515 
516 	if (lvds->panel) {
517 		drm_panel_prepare(lvds->panel);
518 		drm_panel_enable(lvds->panel);
519 	}
520 }
521 
rcar_lvds_disable(struct drm_bridge * bridge)522 static void rcar_lvds_disable(struct drm_bridge *bridge)
523 {
524 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
525 
526 	if (lvds->panel) {
527 		drm_panel_disable(lvds->panel);
528 		drm_panel_unprepare(lvds->panel);
529 	}
530 
531 	rcar_lvds_write(lvds, LVDCR0, 0);
532 	rcar_lvds_write(lvds, LVDCR1, 0);
533 	rcar_lvds_write(lvds, LVDPLLCR, 0);
534 
535 	/* Disable the companion LVDS encoder in dual-link mode. */
536 	if (lvds->dual_link && lvds->companion)
537 		lvds->companion->funcs->disable(lvds->companion);
538 
539 	clk_disable_unprepare(lvds->clocks.mod);
540 }
541 
rcar_lvds_mode_fixup(struct drm_bridge * bridge,const struct drm_display_mode * mode,struct drm_display_mode * adjusted_mode)542 static bool rcar_lvds_mode_fixup(struct drm_bridge *bridge,
543 				 const struct drm_display_mode *mode,
544 				 struct drm_display_mode *adjusted_mode)
545 {
546 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
547 	int min_freq;
548 
549 	/*
550 	 * The internal LVDS encoder has a restricted clock frequency operating
551 	 * range, from 5MHz to 148.5MHz on D3 and E3, and from 31MHz to
552 	 * 148.5MHz on all other platforms. Clamp the clock accordingly.
553 	 */
554 	min_freq = lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL ? 5000 : 31000;
555 	adjusted_mode->clock = clamp(adjusted_mode->clock, min_freq, 148500);
556 
557 	return true;
558 }
559 
rcar_lvds_get_lvds_mode(struct rcar_lvds * lvds)560 static void rcar_lvds_get_lvds_mode(struct rcar_lvds *lvds)
561 {
562 	struct drm_display_info *info = &lvds->connector.display_info;
563 	enum rcar_lvds_mode mode;
564 
565 	/*
566 	 * There is no API yet to retrieve LVDS mode from a bridge, only panels
567 	 * are supported.
568 	 */
569 	if (!lvds->panel)
570 		return;
571 
572 	if (!info->num_bus_formats || !info->bus_formats) {
573 		dev_err(lvds->dev, "no LVDS bus format reported\n");
574 		return;
575 	}
576 
577 	switch (info->bus_formats[0]) {
578 	case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
579 	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
580 		mode = RCAR_LVDS_MODE_JEIDA;
581 		break;
582 	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
583 		mode = RCAR_LVDS_MODE_VESA;
584 		break;
585 	default:
586 		dev_err(lvds->dev, "unsupported LVDS bus format 0x%04x\n",
587 			info->bus_formats[0]);
588 		return;
589 	}
590 
591 	if (info->bus_flags & DRM_BUS_FLAG_DATA_LSB_TO_MSB)
592 		mode |= RCAR_LVDS_MODE_MIRROR;
593 
594 	lvds->mode = mode;
595 }
596 
rcar_lvds_mode_set(struct drm_bridge * bridge,const struct drm_display_mode * mode,const struct drm_display_mode * adjusted_mode)597 static void rcar_lvds_mode_set(struct drm_bridge *bridge,
598 			       const struct drm_display_mode *mode,
599 			       const struct drm_display_mode *adjusted_mode)
600 {
601 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
602 
603 	lvds->display_mode = *adjusted_mode;
604 
605 	rcar_lvds_get_lvds_mode(lvds);
606 }
607 
rcar_lvds_attach(struct drm_bridge * bridge)608 static int rcar_lvds_attach(struct drm_bridge *bridge)
609 {
610 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
611 	struct drm_connector *connector = &lvds->connector;
612 	struct drm_encoder *encoder = bridge->encoder;
613 	int ret;
614 
615 	/* If we have a next bridge just attach it. */
616 	if (lvds->next_bridge)
617 		return drm_bridge_attach(bridge->encoder, lvds->next_bridge,
618 					 bridge);
619 
620 	/* Otherwise if we have a panel, create a connector. */
621 	if (!lvds->panel)
622 		return 0;
623 
624 	ret = drm_connector_init(bridge->dev, connector, &rcar_lvds_conn_funcs,
625 				 DRM_MODE_CONNECTOR_LVDS);
626 	if (ret < 0)
627 		return ret;
628 
629 	drm_connector_helper_add(connector, &rcar_lvds_conn_helper_funcs);
630 
631 	ret = drm_connector_attach_encoder(connector, encoder);
632 	if (ret < 0)
633 		return ret;
634 
635 	return drm_panel_attach(lvds->panel, connector);
636 }
637 
rcar_lvds_detach(struct drm_bridge * bridge)638 static void rcar_lvds_detach(struct drm_bridge *bridge)
639 {
640 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
641 
642 	if (lvds->panel)
643 		drm_panel_detach(lvds->panel);
644 }
645 
646 static const struct drm_bridge_funcs rcar_lvds_bridge_ops = {
647 	.attach = rcar_lvds_attach,
648 	.detach = rcar_lvds_detach,
649 	.enable = rcar_lvds_enable,
650 	.disable = rcar_lvds_disable,
651 	.mode_fixup = rcar_lvds_mode_fixup,
652 	.mode_set = rcar_lvds_mode_set,
653 };
654 
rcar_lvds_dual_link(struct drm_bridge * bridge)655 bool rcar_lvds_dual_link(struct drm_bridge *bridge)
656 {
657 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
658 
659 	return lvds->dual_link;
660 }
661 EXPORT_SYMBOL_GPL(rcar_lvds_dual_link);
662 
663 /* -----------------------------------------------------------------------------
664  * Probe & Remove
665  */
666 
rcar_lvds_parse_dt_companion(struct rcar_lvds * lvds)667 static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
668 {
669 	const struct of_device_id *match;
670 	struct device_node *companion;
671 	struct device *dev = lvds->dev;
672 	int ret = 0;
673 
674 	/* Locate the companion LVDS encoder for dual-link operation, if any. */
675 	companion = of_parse_phandle(dev->of_node, "renesas,companion", 0);
676 	if (!companion)
677 		return 0;
678 
679 	/*
680 	 * Sanity check: the companion encoder must have the same compatible
681 	 * string.
682 	 */
683 	match = of_match_device(dev->driver->of_match_table, dev);
684 	if (!of_device_is_compatible(companion, match->compatible)) {
685 		dev_err(dev, "Companion LVDS encoder is invalid\n");
686 		ret = -ENXIO;
687 		goto done;
688 	}
689 
690 	lvds->companion = of_drm_find_bridge(companion);
691 	if (!lvds->companion) {
692 		ret = -EPROBE_DEFER;
693 		goto done;
694 	}
695 
696 	dev_dbg(dev, "Found companion encoder %pOF\n", companion);
697 
698 done:
699 	of_node_put(companion);
700 
701 	return ret;
702 }
703 
rcar_lvds_parse_dt(struct rcar_lvds * lvds)704 static int rcar_lvds_parse_dt(struct rcar_lvds *lvds)
705 {
706 	struct device_node *local_output = NULL;
707 	struct device_node *remote_input = NULL;
708 	struct device_node *remote = NULL;
709 	struct device_node *node;
710 	bool is_bridge = false;
711 	int ret = 0;
712 
713 	local_output = of_graph_get_endpoint_by_regs(lvds->dev->of_node, 1, 0);
714 	if (!local_output) {
715 		dev_dbg(lvds->dev, "unconnected port@1\n");
716 		ret = -ENODEV;
717 		goto done;
718 	}
719 
720 	/*
721 	 * Locate the connected entity and infer its type from the number of
722 	 * endpoints.
723 	 */
724 	remote = of_graph_get_remote_port_parent(local_output);
725 	if (!remote) {
726 		dev_dbg(lvds->dev, "unconnected endpoint %pOF\n", local_output);
727 		ret = -ENODEV;
728 		goto done;
729 	}
730 
731 	if (!of_device_is_available(remote)) {
732 		dev_dbg(lvds->dev, "connected entity %pOF is disabled\n",
733 			remote);
734 		ret = -ENODEV;
735 		goto done;
736 	}
737 
738 	remote_input = of_graph_get_remote_endpoint(local_output);
739 
740 	for_each_endpoint_of_node(remote, node) {
741 		if (node != remote_input) {
742 			/*
743 			 * We've found one endpoint other than the input, this
744 			 * must be a bridge.
745 			 */
746 			is_bridge = true;
747 			of_node_put(node);
748 			break;
749 		}
750 	}
751 
752 	if (is_bridge) {
753 		lvds->next_bridge = of_drm_find_bridge(remote);
754 		if (!lvds->next_bridge) {
755 			ret = -EPROBE_DEFER;
756 			goto done;
757 		}
758 
759 		if (lvds->info->quirks & RCAR_LVDS_QUIRK_DUAL_LINK)
760 			lvds->dual_link = lvds->next_bridge->timings
761 					? lvds->next_bridge->timings->dual_link
762 					: false;
763 	} else {
764 		lvds->panel = of_drm_find_panel(remote);
765 		if (IS_ERR(lvds->panel)) {
766 			ret = PTR_ERR(lvds->panel);
767 			goto done;
768 		}
769 	}
770 
771 	if (lvds->dual_link)
772 		ret = rcar_lvds_parse_dt_companion(lvds);
773 
774 done:
775 	of_node_put(local_output);
776 	of_node_put(remote_input);
777 	of_node_put(remote);
778 
779 	/*
780 	 * On D3/E3 the LVDS encoder provides a clock to the DU, which can be
781 	 * used for the DPAD output even when the LVDS output is not connected.
782 	 * Don't fail probe in that case as the DU will need the bridge to
783 	 * control the clock.
784 	 */
785 	if (lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL)
786 		return ret == -ENODEV ? 0 : ret;
787 
788 	return ret;
789 }
790 
rcar_lvds_get_clock(struct rcar_lvds * lvds,const char * name,bool optional)791 static struct clk *rcar_lvds_get_clock(struct rcar_lvds *lvds, const char *name,
792 				       bool optional)
793 {
794 	struct clk *clk;
795 
796 	clk = devm_clk_get(lvds->dev, name);
797 	if (!IS_ERR(clk))
798 		return clk;
799 
800 	if (PTR_ERR(clk) == -ENOENT && optional)
801 		return NULL;
802 
803 	if (PTR_ERR(clk) != -EPROBE_DEFER)
804 		dev_err(lvds->dev, "failed to get %s clock\n",
805 			name ? name : "module");
806 
807 	return clk;
808 }
809 
rcar_lvds_get_clocks(struct rcar_lvds * lvds)810 static int rcar_lvds_get_clocks(struct rcar_lvds *lvds)
811 {
812 	lvds->clocks.mod = rcar_lvds_get_clock(lvds, NULL, false);
813 	if (IS_ERR(lvds->clocks.mod))
814 		return PTR_ERR(lvds->clocks.mod);
815 
816 	/*
817 	 * LVDS encoders without an extended PLL have no external clock inputs.
818 	 */
819 	if (!(lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL))
820 		return 0;
821 
822 	lvds->clocks.extal = rcar_lvds_get_clock(lvds, "extal", true);
823 	if (IS_ERR(lvds->clocks.extal))
824 		return PTR_ERR(lvds->clocks.extal);
825 
826 	lvds->clocks.dotclkin[0] = rcar_lvds_get_clock(lvds, "dclkin.0", true);
827 	if (IS_ERR(lvds->clocks.dotclkin[0]))
828 		return PTR_ERR(lvds->clocks.dotclkin[0]);
829 
830 	lvds->clocks.dotclkin[1] = rcar_lvds_get_clock(lvds, "dclkin.1", true);
831 	if (IS_ERR(lvds->clocks.dotclkin[1]))
832 		return PTR_ERR(lvds->clocks.dotclkin[1]);
833 
834 	/* At least one input to the PLL must be available. */
835 	if (!lvds->clocks.extal && !lvds->clocks.dotclkin[0] &&
836 	    !lvds->clocks.dotclkin[1]) {
837 		dev_err(lvds->dev,
838 			"no input clock (extal, dclkin.0 or dclkin.1)\n");
839 		return -EINVAL;
840 	}
841 
842 	return 0;
843 }
844 
rcar_lvds_probe(struct platform_device * pdev)845 static int rcar_lvds_probe(struct platform_device *pdev)
846 {
847 	struct rcar_lvds *lvds;
848 	struct resource *mem;
849 	int ret;
850 
851 	lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
852 	if (lvds == NULL)
853 		return -ENOMEM;
854 
855 	platform_set_drvdata(pdev, lvds);
856 
857 	lvds->dev = &pdev->dev;
858 	lvds->info = of_device_get_match_data(&pdev->dev);
859 
860 	ret = rcar_lvds_parse_dt(lvds);
861 	if (ret < 0)
862 		return ret;
863 
864 	lvds->bridge.driver_private = lvds;
865 	lvds->bridge.funcs = &rcar_lvds_bridge_ops;
866 	lvds->bridge.of_node = pdev->dev.of_node;
867 
868 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
869 	lvds->mmio = devm_ioremap_resource(&pdev->dev, mem);
870 	if (IS_ERR(lvds->mmio))
871 		return PTR_ERR(lvds->mmio);
872 
873 	ret = rcar_lvds_get_clocks(lvds);
874 	if (ret < 0)
875 		return ret;
876 
877 	drm_bridge_add(&lvds->bridge);
878 
879 	return 0;
880 }
881 
rcar_lvds_remove(struct platform_device * pdev)882 static int rcar_lvds_remove(struct platform_device *pdev)
883 {
884 	struct rcar_lvds *lvds = platform_get_drvdata(pdev);
885 
886 	drm_bridge_remove(&lvds->bridge);
887 
888 	return 0;
889 }
890 
891 static const struct rcar_lvds_device_info rcar_lvds_gen2_info = {
892 	.gen = 2,
893 	.pll_setup = rcar_lvds_pll_setup_gen2,
894 };
895 
896 static const struct rcar_lvds_device_info rcar_lvds_r8a7790_info = {
897 	.gen = 2,
898 	.quirks = RCAR_LVDS_QUIRK_LANES,
899 	.pll_setup = rcar_lvds_pll_setup_gen2,
900 };
901 
902 static const struct rcar_lvds_device_info rcar_lvds_gen3_info = {
903 	.gen = 3,
904 	.quirks = RCAR_LVDS_QUIRK_PWD,
905 	.pll_setup = rcar_lvds_pll_setup_gen3,
906 };
907 
908 static const struct rcar_lvds_device_info rcar_lvds_r8a77970_info = {
909 	.gen = 3,
910 	.quirks = RCAR_LVDS_QUIRK_PWD | RCAR_LVDS_QUIRK_GEN3_LVEN,
911 	.pll_setup = rcar_lvds_pll_setup_gen2,
912 };
913 
914 static const struct rcar_lvds_device_info rcar_lvds_r8a77990_info = {
915 	.gen = 3,
916 	.quirks = RCAR_LVDS_QUIRK_GEN3_LVEN | RCAR_LVDS_QUIRK_EXT_PLL
917 		| RCAR_LVDS_QUIRK_DUAL_LINK,
918 	.pll_setup = rcar_lvds_pll_setup_d3_e3,
919 };
920 
921 static const struct rcar_lvds_device_info rcar_lvds_r8a77995_info = {
922 	.gen = 3,
923 	.quirks = RCAR_LVDS_QUIRK_GEN3_LVEN | RCAR_LVDS_QUIRK_PWD
924 		| RCAR_LVDS_QUIRK_EXT_PLL | RCAR_LVDS_QUIRK_DUAL_LINK,
925 	.pll_setup = rcar_lvds_pll_setup_d3_e3,
926 };
927 
928 static const struct of_device_id rcar_lvds_of_table[] = {
929 	{ .compatible = "renesas,r8a7743-lvds", .data = &rcar_lvds_gen2_info },
930 	{ .compatible = "renesas,r8a7744-lvds", .data = &rcar_lvds_gen2_info },
931 	{ .compatible = "renesas,r8a774a1-lvds", .data = &rcar_lvds_gen3_info },
932 	{ .compatible = "renesas,r8a774c0-lvds", .data = &rcar_lvds_r8a77990_info },
933 	{ .compatible = "renesas,r8a7790-lvds", .data = &rcar_lvds_r8a7790_info },
934 	{ .compatible = "renesas,r8a7791-lvds", .data = &rcar_lvds_gen2_info },
935 	{ .compatible = "renesas,r8a7793-lvds", .data = &rcar_lvds_gen2_info },
936 	{ .compatible = "renesas,r8a7795-lvds", .data = &rcar_lvds_gen3_info },
937 	{ .compatible = "renesas,r8a7796-lvds", .data = &rcar_lvds_gen3_info },
938 	{ .compatible = "renesas,r8a77965-lvds", .data = &rcar_lvds_gen3_info },
939 	{ .compatible = "renesas,r8a77970-lvds", .data = &rcar_lvds_r8a77970_info },
940 	{ .compatible = "renesas,r8a77980-lvds", .data = &rcar_lvds_gen3_info },
941 	{ .compatible = "renesas,r8a77990-lvds", .data = &rcar_lvds_r8a77990_info },
942 	{ .compatible = "renesas,r8a77995-lvds", .data = &rcar_lvds_r8a77995_info },
943 	{ }
944 };
945 
946 MODULE_DEVICE_TABLE(of, rcar_lvds_of_table);
947 
948 static struct platform_driver rcar_lvds_platform_driver = {
949 	.probe		= rcar_lvds_probe,
950 	.remove		= rcar_lvds_remove,
951 	.driver		= {
952 		.name	= "rcar-lvds",
953 		.of_match_table = rcar_lvds_of_table,
954 	},
955 };
956 
957 module_platform_driver(rcar_lvds_platform_driver);
958 
959 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
960 MODULE_DESCRIPTION("Renesas R-Car LVDS Encoder Driver");
961 MODULE_LICENSE("GPL");
962