xref: /openbmc/linux/drivers/gpu/drm/omapdrm/dss/dpi.c (revision 2eb0f624b709e78ec8e2f4c3412947703db99301)
1 /*
2  * Copyright (C) 2009 Nokia Corporation
3  * Author: Tomi Valkeinen <tomi.valkeinen@nokia.com>
4  *
5  * Some code and ideas taken from drivers/video/omap/ driver
6  * by Imre Deak.
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License version 2 as published by
10  * the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15  * more details.
16  *
17  * You should have received a copy of the GNU General Public License along with
18  * this program.  If not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #define DSS_SUBSYS_NAME "DPI"
22 
23 #include <linux/kernel.h>
24 #include <linux/delay.h>
25 #include <linux/export.h>
26 #include <linux/err.h>
27 #include <linux/errno.h>
28 #include <linux/platform_device.h>
29 #include <linux/regulator/consumer.h>
30 #include <linux/string.h>
31 #include <linux/of.h>
32 #include <linux/clk.h>
33 #include <linux/sys_soc.h>
34 
35 #include "omapdss.h"
36 #include "dss.h"
37 
38 struct dpi_data {
39 	struct platform_device *pdev;
40 	enum dss_model dss_model;
41 	struct dss_device *dss;
42 
43 	struct regulator *vdds_dsi_reg;
44 	enum dss_clk_source clk_src;
45 	struct dss_pll *pll;
46 
47 	struct mutex lock;
48 
49 	struct videomode vm;
50 	struct dss_lcd_mgr_config mgr_config;
51 	int data_lines;
52 
53 	struct omap_dss_device output;
54 };
55 
56 static struct dpi_data *dpi_get_data_from_dssdev(struct omap_dss_device *dssdev)
57 {
58 	return container_of(dssdev, struct dpi_data, output);
59 }
60 
61 static enum dss_clk_source dpi_get_clk_src_dra7xx(struct dpi_data *dpi,
62 						  enum omap_channel channel)
63 {
64 	/*
65 	 * Possible clock sources:
66 	 * LCD1: FCK/PLL1_1/HDMI_PLL
67 	 * LCD2: FCK/PLL1_3/HDMI_PLL (DRA74x: PLL2_3)
68 	 * LCD3: FCK/PLL1_3/HDMI_PLL (DRA74x: PLL2_1)
69 	 */
70 
71 	switch (channel) {
72 	case OMAP_DSS_CHANNEL_LCD:
73 	{
74 		if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL1_1))
75 			return DSS_CLK_SRC_PLL1_1;
76 		break;
77 	}
78 	case OMAP_DSS_CHANNEL_LCD2:
79 	{
80 		if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL1_3))
81 			return DSS_CLK_SRC_PLL1_3;
82 		if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL2_3))
83 			return DSS_CLK_SRC_PLL2_3;
84 		break;
85 	}
86 	case OMAP_DSS_CHANNEL_LCD3:
87 	{
88 		if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL2_1))
89 			return DSS_CLK_SRC_PLL2_1;
90 		if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL1_3))
91 			return DSS_CLK_SRC_PLL1_3;
92 		break;
93 	}
94 	default:
95 		break;
96 	}
97 
98 	return DSS_CLK_SRC_FCK;
99 }
100 
101 static enum dss_clk_source dpi_get_clk_src(struct dpi_data *dpi)
102 {
103 	enum omap_channel channel = dpi->output.dispc_channel;
104 
105 	/*
106 	 * XXX we can't currently use DSI PLL for DPI with OMAP3, as the DSI PLL
107 	 * would also be used for DISPC fclk. Meaning, when the DPI output is
108 	 * disabled, DISPC clock will be disabled, and TV out will stop.
109 	 */
110 	switch (dpi->dss_model) {
111 	case DSS_MODEL_OMAP2:
112 	case DSS_MODEL_OMAP3:
113 		return DSS_CLK_SRC_FCK;
114 
115 	case DSS_MODEL_OMAP4:
116 		switch (channel) {
117 		case OMAP_DSS_CHANNEL_LCD:
118 			return DSS_CLK_SRC_PLL1_1;
119 		case OMAP_DSS_CHANNEL_LCD2:
120 			return DSS_CLK_SRC_PLL2_1;
121 		default:
122 			return DSS_CLK_SRC_FCK;
123 		}
124 
125 	case DSS_MODEL_OMAP5:
126 		switch (channel) {
127 		case OMAP_DSS_CHANNEL_LCD:
128 			return DSS_CLK_SRC_PLL1_1;
129 		case OMAP_DSS_CHANNEL_LCD3:
130 			return DSS_CLK_SRC_PLL2_1;
131 		case OMAP_DSS_CHANNEL_LCD2:
132 		default:
133 			return DSS_CLK_SRC_FCK;
134 		}
135 
136 	case DSS_MODEL_DRA7:
137 		return dpi_get_clk_src_dra7xx(dpi, channel);
138 
139 	default:
140 		return DSS_CLK_SRC_FCK;
141 	}
142 }
143 
144 struct dpi_clk_calc_ctx {
145 	struct dss_pll *pll;
146 	unsigned int clkout_idx;
147 
148 	/* inputs */
149 
150 	unsigned long pck_min, pck_max;
151 
152 	/* outputs */
153 
154 	struct dss_pll_clock_info pll_cinfo;
155 	unsigned long fck;
156 	struct dispc_clock_info dispc_cinfo;
157 };
158 
159 static bool dpi_calc_dispc_cb(int lckd, int pckd, unsigned long lck,
160 		unsigned long pck, void *data)
161 {
162 	struct dpi_clk_calc_ctx *ctx = data;
163 
164 	/*
165 	 * Odd dividers give us uneven duty cycle, causing problem when level
166 	 * shifted. So skip all odd dividers when the pixel clock is on the
167 	 * higher side.
168 	 */
169 	if (ctx->pck_min >= 100000000) {
170 		if (lckd > 1 && lckd % 2 != 0)
171 			return false;
172 
173 		if (pckd > 1 && pckd % 2 != 0)
174 			return false;
175 	}
176 
177 	ctx->dispc_cinfo.lck_div = lckd;
178 	ctx->dispc_cinfo.pck_div = pckd;
179 	ctx->dispc_cinfo.lck = lck;
180 	ctx->dispc_cinfo.pck = pck;
181 
182 	return true;
183 }
184 
185 
186 static bool dpi_calc_hsdiv_cb(int m_dispc, unsigned long dispc,
187 		void *data)
188 {
189 	struct dpi_clk_calc_ctx *ctx = data;
190 
191 	ctx->pll_cinfo.mX[ctx->clkout_idx] = m_dispc;
192 	ctx->pll_cinfo.clkout[ctx->clkout_idx] = dispc;
193 
194 	return dispc_div_calc(ctx->pll->dss->dispc, dispc,
195 			      ctx->pck_min, ctx->pck_max,
196 			      dpi_calc_dispc_cb, ctx);
197 }
198 
199 
200 static bool dpi_calc_pll_cb(int n, int m, unsigned long fint,
201 		unsigned long clkdco,
202 		void *data)
203 {
204 	struct dpi_clk_calc_ctx *ctx = data;
205 
206 	ctx->pll_cinfo.n = n;
207 	ctx->pll_cinfo.m = m;
208 	ctx->pll_cinfo.fint = fint;
209 	ctx->pll_cinfo.clkdco = clkdco;
210 
211 	return dss_pll_hsdiv_calc_a(ctx->pll, clkdco,
212 		ctx->pck_min, dss_get_max_fck_rate(ctx->pll->dss),
213 		dpi_calc_hsdiv_cb, ctx);
214 }
215 
216 static bool dpi_calc_dss_cb(unsigned long fck, void *data)
217 {
218 	struct dpi_clk_calc_ctx *ctx = data;
219 
220 	ctx->fck = fck;
221 
222 	return dispc_div_calc(ctx->pll->dss->dispc, fck,
223 			      ctx->pck_min, ctx->pck_max,
224 			      dpi_calc_dispc_cb, ctx);
225 }
226 
227 static bool dpi_pll_clk_calc(struct dpi_data *dpi, unsigned long pck,
228 		struct dpi_clk_calc_ctx *ctx)
229 {
230 	unsigned long clkin;
231 
232 	memset(ctx, 0, sizeof(*ctx));
233 	ctx->pll = dpi->pll;
234 	ctx->clkout_idx = dss_pll_get_clkout_idx_for_src(dpi->clk_src);
235 
236 	clkin = clk_get_rate(dpi->pll->clkin);
237 
238 	if (dpi->pll->hw->type == DSS_PLL_TYPE_A) {
239 		unsigned long pll_min, pll_max;
240 
241 		ctx->pck_min = pck - 1000;
242 		ctx->pck_max = pck + 1000;
243 
244 		pll_min = 0;
245 		pll_max = 0;
246 
247 		return dss_pll_calc_a(ctx->pll, clkin,
248 				pll_min, pll_max,
249 				dpi_calc_pll_cb, ctx);
250 	} else { /* DSS_PLL_TYPE_B */
251 		dss_pll_calc_b(dpi->pll, clkin, pck, &ctx->pll_cinfo);
252 
253 		ctx->dispc_cinfo.lck_div = 1;
254 		ctx->dispc_cinfo.pck_div = 1;
255 		ctx->dispc_cinfo.lck = ctx->pll_cinfo.clkout[0];
256 		ctx->dispc_cinfo.pck = ctx->dispc_cinfo.lck;
257 
258 		return true;
259 	}
260 }
261 
262 static bool dpi_dss_clk_calc(struct dpi_data *dpi, unsigned long pck,
263 			     struct dpi_clk_calc_ctx *ctx)
264 {
265 	int i;
266 
267 	/*
268 	 * DSS fck gives us very few possibilities, so finding a good pixel
269 	 * clock may not be possible. We try multiple times to find the clock,
270 	 * each time widening the pixel clock range we look for, up to
271 	 * +/- ~15MHz.
272 	 */
273 
274 	for (i = 0; i < 25; ++i) {
275 		bool ok;
276 
277 		memset(ctx, 0, sizeof(*ctx));
278 		if (pck > 1000 * i * i * i)
279 			ctx->pck_min = max(pck - 1000 * i * i * i, 0lu);
280 		else
281 			ctx->pck_min = 0;
282 		ctx->pck_max = pck + 1000 * i * i * i;
283 
284 		ok = dss_div_calc(dpi->dss, pck, ctx->pck_min,
285 				  dpi_calc_dss_cb, ctx);
286 		if (ok)
287 			return ok;
288 	}
289 
290 	return false;
291 }
292 
293 
294 
295 static int dpi_set_pll_clk(struct dpi_data *dpi, enum omap_channel channel,
296 		unsigned long pck_req, unsigned long *fck, int *lck_div,
297 		int *pck_div)
298 {
299 	struct dpi_clk_calc_ctx ctx;
300 	int r;
301 	bool ok;
302 
303 	ok = dpi_pll_clk_calc(dpi, pck_req, &ctx);
304 	if (!ok)
305 		return -EINVAL;
306 
307 	r = dss_pll_set_config(dpi->pll, &ctx.pll_cinfo);
308 	if (r)
309 		return r;
310 
311 	dss_select_lcd_clk_source(dpi->dss, channel, dpi->clk_src);
312 
313 	dpi->mgr_config.clock_info = ctx.dispc_cinfo;
314 
315 	*fck = ctx.pll_cinfo.clkout[ctx.clkout_idx];
316 	*lck_div = ctx.dispc_cinfo.lck_div;
317 	*pck_div = ctx.dispc_cinfo.pck_div;
318 
319 	return 0;
320 }
321 
322 static int dpi_set_dispc_clk(struct dpi_data *dpi, unsigned long pck_req,
323 		unsigned long *fck, int *lck_div, int *pck_div)
324 {
325 	struct dpi_clk_calc_ctx ctx;
326 	int r;
327 	bool ok;
328 
329 	ok = dpi_dss_clk_calc(dpi, pck_req, &ctx);
330 	if (!ok)
331 		return -EINVAL;
332 
333 	r = dss_set_fck_rate(dpi->dss, ctx.fck);
334 	if (r)
335 		return r;
336 
337 	dpi->mgr_config.clock_info = ctx.dispc_cinfo;
338 
339 	*fck = ctx.fck;
340 	*lck_div = ctx.dispc_cinfo.lck_div;
341 	*pck_div = ctx.dispc_cinfo.pck_div;
342 
343 	return 0;
344 }
345 
346 static int dpi_set_mode(struct dpi_data *dpi)
347 {
348 	struct videomode *vm = &dpi->vm;
349 	int lck_div = 0, pck_div = 0;
350 	unsigned long fck = 0;
351 	unsigned long pck;
352 	int r = 0;
353 
354 	if (dpi->pll)
355 		r = dpi_set_pll_clk(dpi, dpi->output.dispc_channel,
356 				    vm->pixelclock, &fck, &lck_div, &pck_div);
357 	else
358 		r = dpi_set_dispc_clk(dpi, vm->pixelclock, &fck,
359 				&lck_div, &pck_div);
360 	if (r)
361 		return r;
362 
363 	pck = fck / lck_div / pck_div;
364 
365 	if (pck != vm->pixelclock) {
366 		DSSWARN("Could not find exact pixel clock. Requested %lu Hz, got %lu Hz\n",
367 			vm->pixelclock, pck);
368 
369 		vm->pixelclock = pck;
370 	}
371 
372 	dss_mgr_set_timings(&dpi->output, vm);
373 
374 	return 0;
375 }
376 
377 static void dpi_config_lcd_manager(struct dpi_data *dpi)
378 {
379 	dpi->mgr_config.io_pad_mode = DSS_IO_PAD_MODE_BYPASS;
380 
381 	dpi->mgr_config.stallmode = false;
382 	dpi->mgr_config.fifohandcheck = false;
383 
384 	dpi->mgr_config.video_port_width = dpi->data_lines;
385 
386 	dpi->mgr_config.lcden_sig_polarity = 0;
387 
388 	dss_mgr_set_lcd_config(&dpi->output, &dpi->mgr_config);
389 }
390 
391 static int dpi_display_enable(struct omap_dss_device *dssdev)
392 {
393 	struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
394 	struct omap_dss_device *out = &dpi->output;
395 	int r;
396 
397 	mutex_lock(&dpi->lock);
398 
399 	if (!out->dispc_channel_connected) {
400 		DSSERR("failed to enable display: no output/manager\n");
401 		r = -ENODEV;
402 		goto err_no_out_mgr;
403 	}
404 
405 	if (dpi->vdds_dsi_reg) {
406 		r = regulator_enable(dpi->vdds_dsi_reg);
407 		if (r)
408 			goto err_reg_enable;
409 	}
410 
411 	r = dispc_runtime_get(dpi->dss->dispc);
412 	if (r)
413 		goto err_get_dispc;
414 
415 	r = dss_dpi_select_source(dpi->dss, out->port_num, out->dispc_channel);
416 	if (r)
417 		goto err_src_sel;
418 
419 	if (dpi->pll) {
420 		r = dss_pll_enable(dpi->pll);
421 		if (r)
422 			goto err_pll_init;
423 	}
424 
425 	r = dpi_set_mode(dpi);
426 	if (r)
427 		goto err_set_mode;
428 
429 	dpi_config_lcd_manager(dpi);
430 
431 	mdelay(2);
432 
433 	r = dss_mgr_enable(&dpi->output);
434 	if (r)
435 		goto err_mgr_enable;
436 
437 	mutex_unlock(&dpi->lock);
438 
439 	return 0;
440 
441 err_mgr_enable:
442 err_set_mode:
443 	if (dpi->pll)
444 		dss_pll_disable(dpi->pll);
445 err_pll_init:
446 err_src_sel:
447 	dispc_runtime_put(dpi->dss->dispc);
448 err_get_dispc:
449 	if (dpi->vdds_dsi_reg)
450 		regulator_disable(dpi->vdds_dsi_reg);
451 err_reg_enable:
452 err_no_out_mgr:
453 	mutex_unlock(&dpi->lock);
454 	return r;
455 }
456 
457 static void dpi_display_disable(struct omap_dss_device *dssdev)
458 {
459 	struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
460 
461 	mutex_lock(&dpi->lock);
462 
463 	dss_mgr_disable(&dpi->output);
464 
465 	if (dpi->pll) {
466 		dss_select_lcd_clk_source(dpi->dss, dpi->output.dispc_channel,
467 					  DSS_CLK_SRC_FCK);
468 		dss_pll_disable(dpi->pll);
469 	}
470 
471 	dispc_runtime_put(dpi->dss->dispc);
472 
473 	if (dpi->vdds_dsi_reg)
474 		regulator_disable(dpi->vdds_dsi_reg);
475 
476 	mutex_unlock(&dpi->lock);
477 }
478 
479 static void dpi_set_timings(struct omap_dss_device *dssdev,
480 			    struct videomode *vm)
481 {
482 	struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
483 
484 	DSSDBG("dpi_set_timings\n");
485 
486 	mutex_lock(&dpi->lock);
487 
488 	dpi->vm = *vm;
489 
490 	mutex_unlock(&dpi->lock);
491 }
492 
493 static void dpi_get_timings(struct omap_dss_device *dssdev,
494 			    struct videomode *vm)
495 {
496 	struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
497 
498 	mutex_lock(&dpi->lock);
499 
500 	*vm = dpi->vm;
501 
502 	mutex_unlock(&dpi->lock);
503 }
504 
505 static int dpi_check_timings(struct omap_dss_device *dssdev,
506 			     struct videomode *vm)
507 {
508 	struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
509 	enum omap_channel channel = dpi->output.dispc_channel;
510 	int lck_div, pck_div;
511 	unsigned long fck;
512 	unsigned long pck;
513 	struct dpi_clk_calc_ctx ctx;
514 	bool ok;
515 
516 	if (vm->hactive % 8 != 0)
517 		return -EINVAL;
518 
519 	if (!dispc_mgr_timings_ok(dpi->dss->dispc, channel, vm))
520 		return -EINVAL;
521 
522 	if (vm->pixelclock == 0)
523 		return -EINVAL;
524 
525 	if (dpi->pll) {
526 		ok = dpi_pll_clk_calc(dpi, vm->pixelclock, &ctx);
527 		if (!ok)
528 			return -EINVAL;
529 
530 		fck = ctx.pll_cinfo.clkout[ctx.clkout_idx];
531 	} else {
532 		ok = dpi_dss_clk_calc(dpi, vm->pixelclock, &ctx);
533 		if (!ok)
534 			return -EINVAL;
535 
536 		fck = ctx.fck;
537 	}
538 
539 	lck_div = ctx.dispc_cinfo.lck_div;
540 	pck_div = ctx.dispc_cinfo.pck_div;
541 
542 	pck = fck / lck_div / pck_div;
543 
544 	vm->pixelclock = pck;
545 
546 	return 0;
547 }
548 
549 static int dpi_verify_pll(struct dss_pll *pll)
550 {
551 	int r;
552 
553 	/* do initial setup with the PLL to see if it is operational */
554 
555 	r = dss_pll_enable(pll);
556 	if (r)
557 		return r;
558 
559 	dss_pll_disable(pll);
560 
561 	return 0;
562 }
563 
564 static const struct soc_device_attribute dpi_soc_devices[] = {
565 	{ .machine = "OMAP3[456]*" },
566 	{ .machine = "[AD]M37*" },
567 	{ /* sentinel */ }
568 };
569 
570 static int dpi_init_regulator(struct dpi_data *dpi)
571 {
572 	struct regulator *vdds_dsi;
573 
574 	/*
575 	 * The DPI uses the DSI VDDS on OMAP34xx, OMAP35xx, OMAP36xx, AM37xx and
576 	 * DM37xx only.
577 	 */
578 	if (!soc_device_match(dpi_soc_devices))
579 		return 0;
580 
581 	if (dpi->vdds_dsi_reg)
582 		return 0;
583 
584 	vdds_dsi = devm_regulator_get(&dpi->pdev->dev, "vdds_dsi");
585 	if (IS_ERR(vdds_dsi)) {
586 		if (PTR_ERR(vdds_dsi) != -EPROBE_DEFER)
587 			DSSERR("can't get VDDS_DSI regulator\n");
588 		return PTR_ERR(vdds_dsi);
589 	}
590 
591 	dpi->vdds_dsi_reg = vdds_dsi;
592 
593 	return 0;
594 }
595 
596 static void dpi_init_pll(struct dpi_data *dpi)
597 {
598 	struct dss_pll *pll;
599 
600 	if (dpi->pll)
601 		return;
602 
603 	dpi->clk_src = dpi_get_clk_src(dpi);
604 
605 	pll = dss_pll_find_by_src(dpi->dss, dpi->clk_src);
606 	if (!pll)
607 		return;
608 
609 	if (dpi_verify_pll(pll)) {
610 		DSSWARN("PLL not operational\n");
611 		return;
612 	}
613 
614 	dpi->pll = pll;
615 }
616 
617 /*
618  * Return a hardcoded channel for the DPI output. This should work for
619  * current use cases, but this can be later expanded to either resolve
620  * the channel in some more dynamic manner, or get the channel as a user
621  * parameter.
622  */
623 static enum omap_channel dpi_get_channel(struct dpi_data *dpi, int port_num)
624 {
625 	switch (dpi->dss_model) {
626 	case DSS_MODEL_OMAP2:
627 	case DSS_MODEL_OMAP3:
628 		return OMAP_DSS_CHANNEL_LCD;
629 
630 	case DSS_MODEL_DRA7:
631 		switch (port_num) {
632 		case 2:
633 			return OMAP_DSS_CHANNEL_LCD3;
634 		case 1:
635 			return OMAP_DSS_CHANNEL_LCD2;
636 		case 0:
637 		default:
638 			return OMAP_DSS_CHANNEL_LCD;
639 		}
640 
641 	case DSS_MODEL_OMAP4:
642 		return OMAP_DSS_CHANNEL_LCD2;
643 
644 	case DSS_MODEL_OMAP5:
645 		return OMAP_DSS_CHANNEL_LCD3;
646 
647 	default:
648 		DSSWARN("unsupported DSS version\n");
649 		return OMAP_DSS_CHANNEL_LCD;
650 	}
651 }
652 
653 static int dpi_connect(struct omap_dss_device *dssdev,
654 		struct omap_dss_device *dst)
655 {
656 	struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
657 	int r;
658 
659 	r = dpi_init_regulator(dpi);
660 	if (r)
661 		return r;
662 
663 	dpi_init_pll(dpi);
664 
665 	r = dss_mgr_connect(&dpi->output, dssdev);
666 	if (r)
667 		return r;
668 
669 	r = omapdss_output_set_device(dssdev, dst);
670 	if (r) {
671 		DSSERR("failed to connect output to new device: %s\n",
672 				dst->name);
673 		dss_mgr_disconnect(&dpi->output, dssdev);
674 		return r;
675 	}
676 
677 	return 0;
678 }
679 
680 static void dpi_disconnect(struct omap_dss_device *dssdev,
681 		struct omap_dss_device *dst)
682 {
683 	struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
684 
685 	WARN_ON(dst != dssdev->dst);
686 
687 	if (dst != dssdev->dst)
688 		return;
689 
690 	omapdss_output_unset_device(dssdev);
691 
692 	dss_mgr_disconnect(&dpi->output, dssdev);
693 }
694 
695 static const struct omapdss_dpi_ops dpi_ops = {
696 	.connect = dpi_connect,
697 	.disconnect = dpi_disconnect,
698 
699 	.enable = dpi_display_enable,
700 	.disable = dpi_display_disable,
701 
702 	.check_timings = dpi_check_timings,
703 	.set_timings = dpi_set_timings,
704 	.get_timings = dpi_get_timings,
705 };
706 
707 static void dpi_init_output_port(struct dpi_data *dpi, struct device_node *port)
708 {
709 	struct omap_dss_device *out = &dpi->output;
710 	int r;
711 	u32 port_num;
712 
713 	r = of_property_read_u32(port, "reg", &port_num);
714 	if (r)
715 		port_num = 0;
716 
717 	switch (port_num) {
718 	case 2:
719 		out->name = "dpi.2";
720 		break;
721 	case 1:
722 		out->name = "dpi.1";
723 		break;
724 	case 0:
725 	default:
726 		out->name = "dpi.0";
727 		break;
728 	}
729 
730 	out->dev = &dpi->pdev->dev;
731 	out->id = OMAP_DSS_OUTPUT_DPI;
732 	out->output_type = OMAP_DISPLAY_TYPE_DPI;
733 	out->dispc_channel = dpi_get_channel(dpi, port_num);
734 	out->port_num = port_num;
735 	out->ops.dpi = &dpi_ops;
736 	out->owner = THIS_MODULE;
737 
738 	omapdss_register_output(out);
739 }
740 
741 static void dpi_uninit_output_port(struct device_node *port)
742 {
743 	struct dpi_data *dpi = port->data;
744 	struct omap_dss_device *out = &dpi->output;
745 
746 	omapdss_unregister_output(out);
747 }
748 
749 int dpi_init_port(struct dss_device *dss, struct platform_device *pdev,
750 		  struct device_node *port, enum dss_model dss_model)
751 {
752 	struct dpi_data *dpi;
753 	struct device_node *ep;
754 	u32 datalines;
755 	int r;
756 
757 	dpi = devm_kzalloc(&pdev->dev, sizeof(*dpi), GFP_KERNEL);
758 	if (!dpi)
759 		return -ENOMEM;
760 
761 	ep = of_get_next_child(port, NULL);
762 	if (!ep)
763 		return 0;
764 
765 	r = of_property_read_u32(ep, "data-lines", &datalines);
766 	if (r) {
767 		DSSERR("failed to parse datalines\n");
768 		goto err_datalines;
769 	}
770 
771 	dpi->data_lines = datalines;
772 
773 	of_node_put(ep);
774 
775 	dpi->pdev = pdev;
776 	dpi->dss_model = dss_model;
777 	dpi->dss = dss;
778 	port->data = dpi;
779 
780 	mutex_init(&dpi->lock);
781 
782 	dpi_init_output_port(dpi, port);
783 
784 	return 0;
785 
786 err_datalines:
787 	of_node_put(ep);
788 
789 	return r;
790 }
791 
792 void dpi_uninit_port(struct device_node *port)
793 {
794 	struct dpi_data *dpi = port->data;
795 
796 	if (!dpi)
797 		return;
798 
799 	dpi_uninit_output_port(port);
800 }
801