xref: /openbmc/linux/drivers/gpu/drm/omapdrm/dss/dpi.c (revision 7f2e85840871f199057e65232ebde846192ed989)
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 
42 	struct regulator *vdds_dsi_reg;
43 	enum dss_clk_source clk_src;
44 	struct dss_pll *pll;
45 
46 	struct mutex lock;
47 
48 	struct videomode vm;
49 	struct dss_lcd_mgr_config mgr_config;
50 	int data_lines;
51 
52 	struct omap_dss_device output;
53 };
54 
55 static struct dpi_data *dpi_get_data_from_dssdev(struct omap_dss_device *dssdev)
56 {
57 	return container_of(dssdev, struct dpi_data, output);
58 }
59 
60 static enum dss_clk_source dpi_get_clk_src_dra7xx(enum omap_channel channel)
61 {
62 	/*
63 	 * Possible clock sources:
64 	 * LCD1: FCK/PLL1_1/HDMI_PLL
65 	 * LCD2: FCK/PLL1_3/HDMI_PLL (DRA74x: PLL2_3)
66 	 * LCD3: FCK/PLL1_3/HDMI_PLL (DRA74x: PLL2_1)
67 	 */
68 
69 	switch (channel) {
70 	case OMAP_DSS_CHANNEL_LCD:
71 	{
72 		if (dss_pll_find_by_src(DSS_CLK_SRC_PLL1_1))
73 			return DSS_CLK_SRC_PLL1_1;
74 		break;
75 	}
76 	case OMAP_DSS_CHANNEL_LCD2:
77 	{
78 		if (dss_pll_find_by_src(DSS_CLK_SRC_PLL1_3))
79 			return DSS_CLK_SRC_PLL1_3;
80 		if (dss_pll_find_by_src(DSS_CLK_SRC_PLL2_3))
81 			return DSS_CLK_SRC_PLL2_3;
82 		break;
83 	}
84 	case OMAP_DSS_CHANNEL_LCD3:
85 	{
86 		if (dss_pll_find_by_src(DSS_CLK_SRC_PLL2_1))
87 			return DSS_CLK_SRC_PLL2_1;
88 		if (dss_pll_find_by_src(DSS_CLK_SRC_PLL1_3))
89 			return DSS_CLK_SRC_PLL1_3;
90 		break;
91 	}
92 	default:
93 		break;
94 	}
95 
96 	return DSS_CLK_SRC_FCK;
97 }
98 
99 static enum dss_clk_source dpi_get_clk_src(struct dpi_data *dpi)
100 {
101 	enum omap_channel channel = dpi->output.dispc_channel;
102 
103 	/*
104 	 * XXX we can't currently use DSI PLL for DPI with OMAP3, as the DSI PLL
105 	 * would also be used for DISPC fclk. Meaning, when the DPI output is
106 	 * disabled, DISPC clock will be disabled, and TV out will stop.
107 	 */
108 	switch (dpi->dss_model) {
109 	case DSS_MODEL_OMAP2:
110 	case DSS_MODEL_OMAP3:
111 		return DSS_CLK_SRC_FCK;
112 
113 	case DSS_MODEL_OMAP4:
114 		switch (channel) {
115 		case OMAP_DSS_CHANNEL_LCD:
116 			return DSS_CLK_SRC_PLL1_1;
117 		case OMAP_DSS_CHANNEL_LCD2:
118 			return DSS_CLK_SRC_PLL2_1;
119 		default:
120 			return DSS_CLK_SRC_FCK;
121 		}
122 
123 	case DSS_MODEL_OMAP5:
124 		switch (channel) {
125 		case OMAP_DSS_CHANNEL_LCD:
126 			return DSS_CLK_SRC_PLL1_1;
127 		case OMAP_DSS_CHANNEL_LCD3:
128 			return DSS_CLK_SRC_PLL2_1;
129 		case OMAP_DSS_CHANNEL_LCD2:
130 		default:
131 			return DSS_CLK_SRC_FCK;
132 		}
133 
134 	case DSS_MODEL_DRA7:
135 		return dpi_get_clk_src_dra7xx(channel);
136 
137 	default:
138 		return DSS_CLK_SRC_FCK;
139 	}
140 }
141 
142 struct dpi_clk_calc_ctx {
143 	struct dss_pll *pll;
144 	unsigned clkout_idx;
145 
146 	/* inputs */
147 
148 	unsigned long pck_min, pck_max;
149 
150 	/* outputs */
151 
152 	struct dss_pll_clock_info pll_cinfo;
153 	unsigned long fck;
154 	struct dispc_clock_info dispc_cinfo;
155 };
156 
157 static bool dpi_calc_dispc_cb(int lckd, int pckd, unsigned long lck,
158 		unsigned long pck, void *data)
159 {
160 	struct dpi_clk_calc_ctx *ctx = data;
161 
162 	/*
163 	 * Odd dividers give us uneven duty cycle, causing problem when level
164 	 * shifted. So skip all odd dividers when the pixel clock is on the
165 	 * higher side.
166 	 */
167 	if (ctx->pck_min >= 100000000) {
168 		if (lckd > 1 && lckd % 2 != 0)
169 			return false;
170 
171 		if (pckd > 1 && pckd % 2 != 0)
172 			return false;
173 	}
174 
175 	ctx->dispc_cinfo.lck_div = lckd;
176 	ctx->dispc_cinfo.pck_div = pckd;
177 	ctx->dispc_cinfo.lck = lck;
178 	ctx->dispc_cinfo.pck = pck;
179 
180 	return true;
181 }
182 
183 
184 static bool dpi_calc_hsdiv_cb(int m_dispc, unsigned long dispc,
185 		void *data)
186 {
187 	struct dpi_clk_calc_ctx *ctx = data;
188 
189 	ctx->pll_cinfo.mX[ctx->clkout_idx] = m_dispc;
190 	ctx->pll_cinfo.clkout[ctx->clkout_idx] = dispc;
191 
192 	return dispc_div_calc(dispc, ctx->pck_min, ctx->pck_max,
193 			dpi_calc_dispc_cb, ctx);
194 }
195 
196 
197 static bool dpi_calc_pll_cb(int n, int m, unsigned long fint,
198 		unsigned long clkdco,
199 		void *data)
200 {
201 	struct dpi_clk_calc_ctx *ctx = data;
202 
203 	ctx->pll_cinfo.n = n;
204 	ctx->pll_cinfo.m = m;
205 	ctx->pll_cinfo.fint = fint;
206 	ctx->pll_cinfo.clkdco = clkdco;
207 
208 	return dss_pll_hsdiv_calc_a(ctx->pll, clkdco,
209 		ctx->pck_min, dss_get_max_fck_rate(),
210 		dpi_calc_hsdiv_cb, ctx);
211 }
212 
213 static bool dpi_calc_dss_cb(unsigned long fck, void *data)
214 {
215 	struct dpi_clk_calc_ctx *ctx = data;
216 
217 	ctx->fck = fck;
218 
219 	return dispc_div_calc(fck, ctx->pck_min, ctx->pck_max,
220 			dpi_calc_dispc_cb, ctx);
221 }
222 
223 static bool dpi_pll_clk_calc(struct dpi_data *dpi, unsigned long pck,
224 		struct dpi_clk_calc_ctx *ctx)
225 {
226 	unsigned long clkin;
227 
228 	memset(ctx, 0, sizeof(*ctx));
229 	ctx->pll = dpi->pll;
230 	ctx->clkout_idx = dss_pll_get_clkout_idx_for_src(dpi->clk_src);
231 
232 	clkin = clk_get_rate(dpi->pll->clkin);
233 
234 	if (dpi->pll->hw->type == DSS_PLL_TYPE_A) {
235 		unsigned long pll_min, pll_max;
236 
237 		ctx->pck_min = pck - 1000;
238 		ctx->pck_max = pck + 1000;
239 
240 		pll_min = 0;
241 		pll_max = 0;
242 
243 		return dss_pll_calc_a(ctx->pll, clkin,
244 				pll_min, pll_max,
245 				dpi_calc_pll_cb, ctx);
246 	} else { /* DSS_PLL_TYPE_B */
247 		dss_pll_calc_b(dpi->pll, clkin, pck, &ctx->pll_cinfo);
248 
249 		ctx->dispc_cinfo.lck_div = 1;
250 		ctx->dispc_cinfo.pck_div = 1;
251 		ctx->dispc_cinfo.lck = ctx->pll_cinfo.clkout[0];
252 		ctx->dispc_cinfo.pck = ctx->dispc_cinfo.lck;
253 
254 		return true;
255 	}
256 }
257 
258 static bool dpi_dss_clk_calc(unsigned long pck, struct dpi_clk_calc_ctx *ctx)
259 {
260 	int i;
261 
262 	/*
263 	 * DSS fck gives us very few possibilities, so finding a good pixel
264 	 * clock may not be possible. We try multiple times to find the clock,
265 	 * each time widening the pixel clock range we look for, up to
266 	 * +/- ~15MHz.
267 	 */
268 
269 	for (i = 0; i < 25; ++i) {
270 		bool ok;
271 
272 		memset(ctx, 0, sizeof(*ctx));
273 		if (pck > 1000 * i * i * i)
274 			ctx->pck_min = max(pck - 1000 * i * i * i, 0lu);
275 		else
276 			ctx->pck_min = 0;
277 		ctx->pck_max = pck + 1000 * i * i * i;
278 
279 		ok = dss_div_calc(pck, ctx->pck_min, dpi_calc_dss_cb, ctx);
280 		if (ok)
281 			return ok;
282 	}
283 
284 	return false;
285 }
286 
287 
288 
289 static int dpi_set_pll_clk(struct dpi_data *dpi, enum omap_channel channel,
290 		unsigned long pck_req, unsigned long *fck, int *lck_div,
291 		int *pck_div)
292 {
293 	struct dpi_clk_calc_ctx ctx;
294 	int r;
295 	bool ok;
296 
297 	ok = dpi_pll_clk_calc(dpi, pck_req, &ctx);
298 	if (!ok)
299 		return -EINVAL;
300 
301 	r = dss_pll_set_config(dpi->pll, &ctx.pll_cinfo);
302 	if (r)
303 		return r;
304 
305 	dss_select_lcd_clk_source(channel, dpi->clk_src);
306 
307 	dpi->mgr_config.clock_info = ctx.dispc_cinfo;
308 
309 	*fck = ctx.pll_cinfo.clkout[ctx.clkout_idx];
310 	*lck_div = ctx.dispc_cinfo.lck_div;
311 	*pck_div = ctx.dispc_cinfo.pck_div;
312 
313 	return 0;
314 }
315 
316 static int dpi_set_dispc_clk(struct dpi_data *dpi, unsigned long pck_req,
317 		unsigned long *fck, int *lck_div, int *pck_div)
318 {
319 	struct dpi_clk_calc_ctx ctx;
320 	int r;
321 	bool ok;
322 
323 	ok = dpi_dss_clk_calc(pck_req, &ctx);
324 	if (!ok)
325 		return -EINVAL;
326 
327 	r = dss_set_fck_rate(ctx.fck);
328 	if (r)
329 		return r;
330 
331 	dpi->mgr_config.clock_info = ctx.dispc_cinfo;
332 
333 	*fck = ctx.fck;
334 	*lck_div = ctx.dispc_cinfo.lck_div;
335 	*pck_div = ctx.dispc_cinfo.pck_div;
336 
337 	return 0;
338 }
339 
340 static int dpi_set_mode(struct dpi_data *dpi)
341 {
342 	struct omap_dss_device *out = &dpi->output;
343 	enum omap_channel channel = out->dispc_channel;
344 	struct videomode *vm = &dpi->vm;
345 	int lck_div = 0, pck_div = 0;
346 	unsigned long fck = 0;
347 	unsigned long pck;
348 	int r = 0;
349 
350 	if (dpi->pll)
351 		r = dpi_set_pll_clk(dpi, channel, vm->pixelclock, &fck,
352 				&lck_div, &pck_div);
353 	else
354 		r = dpi_set_dispc_clk(dpi, vm->pixelclock, &fck,
355 				&lck_div, &pck_div);
356 	if (r)
357 		return r;
358 
359 	pck = fck / lck_div / pck_div;
360 
361 	if (pck != vm->pixelclock) {
362 		DSSWARN("Could not find exact pixel clock. Requested %lu Hz, got %lu Hz\n",
363 			vm->pixelclock, pck);
364 
365 		vm->pixelclock = pck;
366 	}
367 
368 	dss_mgr_set_timings(channel, vm);
369 
370 	return 0;
371 }
372 
373 static void dpi_config_lcd_manager(struct dpi_data *dpi)
374 {
375 	struct omap_dss_device *out = &dpi->output;
376 	enum omap_channel channel = out->dispc_channel;
377 
378 	dpi->mgr_config.io_pad_mode = DSS_IO_PAD_MODE_BYPASS;
379 
380 	dpi->mgr_config.stallmode = false;
381 	dpi->mgr_config.fifohandcheck = false;
382 
383 	dpi->mgr_config.video_port_width = dpi->data_lines;
384 
385 	dpi->mgr_config.lcden_sig_polarity = 0;
386 
387 	dss_mgr_set_lcd_config(channel, &dpi->mgr_config);
388 }
389 
390 static int dpi_display_enable(struct omap_dss_device *dssdev)
391 {
392 	struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
393 	struct omap_dss_device *out = &dpi->output;
394 	enum omap_channel channel = out->dispc_channel;
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();
412 	if (r)
413 		goto err_get_dispc;
414 
415 	r = dss_dpi_select_source(out->port_num, 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(channel);
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();
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 	enum omap_channel channel = dpi->output.dispc_channel;
461 
462 	mutex_lock(&dpi->lock);
463 
464 	dss_mgr_disable(channel);
465 
466 	if (dpi->pll) {
467 		dss_select_lcd_clk_source(channel, DSS_CLK_SRC_FCK);
468 		dss_pll_disable(dpi->pll);
469 	}
470 
471 	dispc_runtime_put();
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(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(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->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 	enum omap_channel channel = dpi->output.dispc_channel;
658 	int r;
659 
660 	r = dpi_init_regulator(dpi);
661 	if (r)
662 		return r;
663 
664 	dpi_init_pll(dpi);
665 
666 	r = dss_mgr_connect(channel, dssdev);
667 	if (r)
668 		return r;
669 
670 	r = omapdss_output_set_device(dssdev, dst);
671 	if (r) {
672 		DSSERR("failed to connect output to new device: %s\n",
673 				dst->name);
674 		dss_mgr_disconnect(channel, dssdev);
675 		return r;
676 	}
677 
678 	return 0;
679 }
680 
681 static void dpi_disconnect(struct omap_dss_device *dssdev,
682 		struct omap_dss_device *dst)
683 {
684 	struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
685 	enum omap_channel channel = dpi->output.dispc_channel;
686 
687 	WARN_ON(dst != dssdev->dst);
688 
689 	if (dst != dssdev->dst)
690 		return;
691 
692 	omapdss_output_unset_device(dssdev);
693 
694 	dss_mgr_disconnect(channel, dssdev);
695 }
696 
697 static const struct omapdss_dpi_ops dpi_ops = {
698 	.connect = dpi_connect,
699 	.disconnect = dpi_disconnect,
700 
701 	.enable = dpi_display_enable,
702 	.disable = dpi_display_disable,
703 
704 	.check_timings = dpi_check_timings,
705 	.set_timings = dpi_set_timings,
706 	.get_timings = dpi_get_timings,
707 };
708 
709 static void dpi_init_output_port(struct dpi_data *dpi, struct device_node *port)
710 {
711 	struct omap_dss_device *out = &dpi->output;
712 	int r;
713 	u32 port_num;
714 
715 	r = of_property_read_u32(port, "reg", &port_num);
716 	if (r)
717 		port_num = 0;
718 
719 	switch (port_num) {
720 	case 2:
721 		out->name = "dpi.2";
722 		break;
723 	case 1:
724 		out->name = "dpi.1";
725 		break;
726 	case 0:
727 	default:
728 		out->name = "dpi.0";
729 		break;
730 	}
731 
732 	out->dev = &dpi->pdev->dev;
733 	out->id = OMAP_DSS_OUTPUT_DPI;
734 	out->output_type = OMAP_DISPLAY_TYPE_DPI;
735 	out->dispc_channel = dpi_get_channel(dpi, port_num);
736 	out->port_num = port_num;
737 	out->ops.dpi = &dpi_ops;
738 	out->owner = THIS_MODULE;
739 
740 	omapdss_register_output(out);
741 }
742 
743 static void dpi_uninit_output_port(struct device_node *port)
744 {
745 	struct dpi_data *dpi = port->data;
746 	struct omap_dss_device *out = &dpi->output;
747 
748 	omapdss_unregister_output(out);
749 }
750 
751 int dpi_init_port(struct platform_device *pdev, struct device_node *port,
752 		  enum dss_model dss_model)
753 {
754 	struct dpi_data *dpi;
755 	struct device_node *ep;
756 	u32 datalines;
757 	int r;
758 
759 	dpi = devm_kzalloc(&pdev->dev, sizeof(*dpi), GFP_KERNEL);
760 	if (!dpi)
761 		return -ENOMEM;
762 
763 	ep = of_get_next_child(port, NULL);
764 	if (!ep)
765 		return 0;
766 
767 	r = of_property_read_u32(ep, "data-lines", &datalines);
768 	if (r) {
769 		DSSERR("failed to parse datalines\n");
770 		goto err_datalines;
771 	}
772 
773 	dpi->data_lines = datalines;
774 
775 	of_node_put(ep);
776 
777 	dpi->pdev = pdev;
778 	dpi->dss_model = dss_model;
779 	port->data = dpi;
780 
781 	mutex_init(&dpi->lock);
782 
783 	dpi_init_output_port(dpi, port);
784 
785 	return 0;
786 
787 err_datalines:
788 	of_node_put(ep);
789 
790 	return r;
791 }
792 
793 void dpi_uninit_port(struct device_node *port)
794 {
795 	struct dpi_data *dpi = port->data;
796 
797 	if (!dpi)
798 		return;
799 
800 	dpi_uninit_output_port(port);
801 }
802