xref: /openbmc/linux/drivers/gpu/drm/omapdrm/dss/dpi.c (revision ccb01374)
1 /*
2  * Copyright (C) 2009 Nokia Corporation
3  * Author: Tomi Valkeinen <tomi.valkeinen@ti.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 	unsigned int id;
43 
44 	struct regulator *vdds_dsi_reg;
45 	enum dss_clk_source clk_src;
46 	struct dss_pll *pll;
47 
48 	struct mutex lock;
49 
50 	struct videomode vm;
51 	struct dss_lcd_mgr_config mgr_config;
52 	int data_lines;
53 
54 	struct omap_dss_device output;
55 };
56 
57 static struct dpi_data *dpi_get_data_from_dssdev(struct omap_dss_device *dssdev)
58 {
59 	return container_of(dssdev, struct dpi_data, output);
60 }
61 
62 static enum dss_clk_source dpi_get_clk_src_dra7xx(struct dpi_data *dpi,
63 						  enum omap_channel channel)
64 {
65 	/*
66 	 * Possible clock sources:
67 	 * LCD1: FCK/PLL1_1/HDMI_PLL
68 	 * LCD2: FCK/PLL1_3/HDMI_PLL (DRA74x: PLL2_3)
69 	 * LCD3: FCK/PLL1_3/HDMI_PLL (DRA74x: PLL2_1)
70 	 */
71 
72 	switch (channel) {
73 	case OMAP_DSS_CHANNEL_LCD:
74 	{
75 		if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL1_1))
76 			return DSS_CLK_SRC_PLL1_1;
77 		break;
78 	}
79 	case OMAP_DSS_CHANNEL_LCD2:
80 	{
81 		if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL1_3))
82 			return DSS_CLK_SRC_PLL1_3;
83 		if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL2_3))
84 			return DSS_CLK_SRC_PLL2_3;
85 		break;
86 	}
87 	case OMAP_DSS_CHANNEL_LCD3:
88 	{
89 		if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL2_1))
90 			return DSS_CLK_SRC_PLL2_1;
91 		if (dss_pll_find_by_src(dpi->dss, DSS_CLK_SRC_PLL1_3))
92 			return DSS_CLK_SRC_PLL1_3;
93 		break;
94 	}
95 	default:
96 		break;
97 	}
98 
99 	return DSS_CLK_SRC_FCK;
100 }
101 
102 static enum dss_clk_source dpi_get_clk_src(struct dpi_data *dpi)
103 {
104 	enum omap_channel channel = dpi->output.dispc_channel;
105 
106 	/*
107 	 * XXX we can't currently use DSI PLL for DPI with OMAP3, as the DSI PLL
108 	 * would also be used for DISPC fclk. Meaning, when the DPI output is
109 	 * disabled, DISPC clock will be disabled, and TV out will stop.
110 	 */
111 	switch (dpi->dss_model) {
112 	case DSS_MODEL_OMAP2:
113 	case DSS_MODEL_OMAP3:
114 		return DSS_CLK_SRC_FCK;
115 
116 	case DSS_MODEL_OMAP4:
117 		switch (channel) {
118 		case OMAP_DSS_CHANNEL_LCD:
119 			return DSS_CLK_SRC_PLL1_1;
120 		case OMAP_DSS_CHANNEL_LCD2:
121 			return DSS_CLK_SRC_PLL2_1;
122 		default:
123 			return DSS_CLK_SRC_FCK;
124 		}
125 
126 	case DSS_MODEL_OMAP5:
127 		switch (channel) {
128 		case OMAP_DSS_CHANNEL_LCD:
129 			return DSS_CLK_SRC_PLL1_1;
130 		case OMAP_DSS_CHANNEL_LCD3:
131 			return DSS_CLK_SRC_PLL2_1;
132 		case OMAP_DSS_CHANNEL_LCD2:
133 		default:
134 			return DSS_CLK_SRC_FCK;
135 		}
136 
137 	case DSS_MODEL_DRA7:
138 		return dpi_get_clk_src_dra7xx(dpi, channel);
139 
140 	default:
141 		return DSS_CLK_SRC_FCK;
142 	}
143 }
144 
145 struct dpi_clk_calc_ctx {
146 	struct dpi_data *dpi;
147 	unsigned int clkout_idx;
148 
149 	/* inputs */
150 
151 	unsigned long pck_min, pck_max;
152 
153 	/* outputs */
154 
155 	struct dss_pll_clock_info pll_cinfo;
156 	unsigned long fck;
157 	struct dispc_clock_info dispc_cinfo;
158 };
159 
160 static bool dpi_calc_dispc_cb(int lckd, int pckd, unsigned long lck,
161 		unsigned long pck, void *data)
162 {
163 	struct dpi_clk_calc_ctx *ctx = data;
164 
165 	/*
166 	 * Odd dividers give us uneven duty cycle, causing problem when level
167 	 * shifted. So skip all odd dividers when the pixel clock is on the
168 	 * higher side.
169 	 */
170 	if (ctx->pck_min >= 100000000) {
171 		if (lckd > 1 && lckd % 2 != 0)
172 			return false;
173 
174 		if (pckd > 1 && pckd % 2 != 0)
175 			return false;
176 	}
177 
178 	ctx->dispc_cinfo.lck_div = lckd;
179 	ctx->dispc_cinfo.pck_div = pckd;
180 	ctx->dispc_cinfo.lck = lck;
181 	ctx->dispc_cinfo.pck = pck;
182 
183 	return true;
184 }
185 
186 
187 static bool dpi_calc_hsdiv_cb(int m_dispc, unsigned long dispc,
188 		void *data)
189 {
190 	struct dpi_clk_calc_ctx *ctx = data;
191 
192 	ctx->pll_cinfo.mX[ctx->clkout_idx] = m_dispc;
193 	ctx->pll_cinfo.clkout[ctx->clkout_idx] = dispc;
194 
195 	return dispc_div_calc(ctx->dpi->dss->dispc, dispc,
196 			      ctx->pck_min, ctx->pck_max,
197 			      dpi_calc_dispc_cb, ctx);
198 }
199 
200 
201 static bool dpi_calc_pll_cb(int n, int m, unsigned long fint,
202 		unsigned long clkdco,
203 		void *data)
204 {
205 	struct dpi_clk_calc_ctx *ctx = data;
206 
207 	ctx->pll_cinfo.n = n;
208 	ctx->pll_cinfo.m = m;
209 	ctx->pll_cinfo.fint = fint;
210 	ctx->pll_cinfo.clkdco = clkdco;
211 
212 	return dss_pll_hsdiv_calc_a(ctx->dpi->pll, clkdco,
213 		ctx->pck_min, dss_get_max_fck_rate(ctx->dpi->dss),
214 		dpi_calc_hsdiv_cb, ctx);
215 }
216 
217 static bool dpi_calc_dss_cb(unsigned long fck, void *data)
218 {
219 	struct dpi_clk_calc_ctx *ctx = data;
220 
221 	ctx->fck = fck;
222 
223 	return dispc_div_calc(ctx->dpi->dss->dispc, fck,
224 			      ctx->pck_min, ctx->pck_max,
225 			      dpi_calc_dispc_cb, ctx);
226 }
227 
228 static bool dpi_pll_clk_calc(struct dpi_data *dpi, unsigned long pck,
229 		struct dpi_clk_calc_ctx *ctx)
230 {
231 	unsigned long clkin;
232 
233 	memset(ctx, 0, sizeof(*ctx));
234 	ctx->dpi = dpi;
235 	ctx->clkout_idx = dss_pll_get_clkout_idx_for_src(dpi->clk_src);
236 
237 	clkin = clk_get_rate(dpi->pll->clkin);
238 
239 	if (dpi->pll->hw->type == DSS_PLL_TYPE_A) {
240 		unsigned long pll_min, pll_max;
241 
242 		ctx->pck_min = pck - 1000;
243 		ctx->pck_max = pck + 1000;
244 
245 		pll_min = 0;
246 		pll_max = 0;
247 
248 		return dss_pll_calc_a(ctx->dpi->pll, clkin,
249 				pll_min, pll_max,
250 				dpi_calc_pll_cb, ctx);
251 	} else { /* DSS_PLL_TYPE_B */
252 		dss_pll_calc_b(dpi->pll, clkin, pck, &ctx->pll_cinfo);
253 
254 		ctx->dispc_cinfo.lck_div = 1;
255 		ctx->dispc_cinfo.pck_div = 1;
256 		ctx->dispc_cinfo.lck = ctx->pll_cinfo.clkout[0];
257 		ctx->dispc_cinfo.pck = ctx->dispc_cinfo.lck;
258 
259 		return true;
260 	}
261 }
262 
263 static bool dpi_dss_clk_calc(struct dpi_data *dpi, unsigned long pck,
264 			     struct dpi_clk_calc_ctx *ctx)
265 {
266 	int i;
267 
268 	/*
269 	 * DSS fck gives us very few possibilities, so finding a good pixel
270 	 * clock may not be possible. We try multiple times to find the clock,
271 	 * each time widening the pixel clock range we look for, up to
272 	 * +/- ~15MHz.
273 	 */
274 
275 	for (i = 0; i < 25; ++i) {
276 		bool ok;
277 
278 		memset(ctx, 0, sizeof(*ctx));
279 		ctx->dpi = dpi;
280 		if (pck > 1000 * i * i * i)
281 			ctx->pck_min = max(pck - 1000 * i * i * i, 0lu);
282 		else
283 			ctx->pck_min = 0;
284 		ctx->pck_max = pck + 1000 * i * i * i;
285 
286 		ok = dss_div_calc(dpi->dss, pck, ctx->pck_min,
287 				  dpi_calc_dss_cb, ctx);
288 		if (ok)
289 			return ok;
290 	}
291 
292 	return false;
293 }
294 
295 
296 
297 static int dpi_set_pll_clk(struct dpi_data *dpi, enum omap_channel channel,
298 		unsigned long pck_req, unsigned long *fck, int *lck_div,
299 		int *pck_div)
300 {
301 	struct dpi_clk_calc_ctx ctx;
302 	int r;
303 	bool ok;
304 
305 	ok = dpi_pll_clk_calc(dpi, pck_req, &ctx);
306 	if (!ok)
307 		return -EINVAL;
308 
309 	r = dss_pll_set_config(dpi->pll, &ctx.pll_cinfo);
310 	if (r)
311 		return r;
312 
313 	dss_select_lcd_clk_source(dpi->dss, channel, dpi->clk_src);
314 
315 	dpi->mgr_config.clock_info = ctx.dispc_cinfo;
316 
317 	*fck = ctx.pll_cinfo.clkout[ctx.clkout_idx];
318 	*lck_div = ctx.dispc_cinfo.lck_div;
319 	*pck_div = ctx.dispc_cinfo.pck_div;
320 
321 	return 0;
322 }
323 
324 static int dpi_set_dispc_clk(struct dpi_data *dpi, unsigned long pck_req,
325 		unsigned long *fck, int *lck_div, int *pck_div)
326 {
327 	struct dpi_clk_calc_ctx ctx;
328 	int r;
329 	bool ok;
330 
331 	ok = dpi_dss_clk_calc(dpi, pck_req, &ctx);
332 	if (!ok)
333 		return -EINVAL;
334 
335 	r = dss_set_fck_rate(dpi->dss, ctx.fck);
336 	if (r)
337 		return r;
338 
339 	dpi->mgr_config.clock_info = ctx.dispc_cinfo;
340 
341 	*fck = ctx.fck;
342 	*lck_div = ctx.dispc_cinfo.lck_div;
343 	*pck_div = ctx.dispc_cinfo.pck_div;
344 
345 	return 0;
346 }
347 
348 static int dpi_set_mode(struct dpi_data *dpi)
349 {
350 	const struct videomode *vm = &dpi->vm;
351 	int lck_div = 0, pck_div = 0;
352 	unsigned long fck = 0;
353 	int r = 0;
354 
355 	if (dpi->pll)
356 		r = dpi_set_pll_clk(dpi, dpi->output.dispc_channel,
357 				    vm->pixelclock, &fck, &lck_div, &pck_div);
358 	else
359 		r = dpi_set_dispc_clk(dpi, vm->pixelclock, &fck,
360 				&lck_div, &pck_div);
361 	if (r)
362 		return r;
363 
364 	return 0;
365 }
366 
367 static void dpi_config_lcd_manager(struct dpi_data *dpi)
368 {
369 	dpi->mgr_config.io_pad_mode = DSS_IO_PAD_MODE_BYPASS;
370 
371 	dpi->mgr_config.stallmode = false;
372 	dpi->mgr_config.fifohandcheck = false;
373 
374 	dpi->mgr_config.video_port_width = dpi->data_lines;
375 
376 	dpi->mgr_config.lcden_sig_polarity = 0;
377 
378 	dss_mgr_set_lcd_config(&dpi->output, &dpi->mgr_config);
379 }
380 
381 static int dpi_display_enable(struct omap_dss_device *dssdev)
382 {
383 	struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
384 	struct omap_dss_device *out = &dpi->output;
385 	int r;
386 
387 	mutex_lock(&dpi->lock);
388 
389 	if (!out->dispc_channel_connected) {
390 		DSSERR("failed to enable display: no output/manager\n");
391 		r = -ENODEV;
392 		goto err_no_out_mgr;
393 	}
394 
395 	if (dpi->vdds_dsi_reg) {
396 		r = regulator_enable(dpi->vdds_dsi_reg);
397 		if (r)
398 			goto err_reg_enable;
399 	}
400 
401 	r = dispc_runtime_get(dpi->dss->dispc);
402 	if (r)
403 		goto err_get_dispc;
404 
405 	r = dss_dpi_select_source(dpi->dss, dpi->id, out->dispc_channel);
406 	if (r)
407 		goto err_src_sel;
408 
409 	if (dpi->pll) {
410 		r = dss_pll_enable(dpi->pll);
411 		if (r)
412 			goto err_pll_init;
413 	}
414 
415 	r = dpi_set_mode(dpi);
416 	if (r)
417 		goto err_set_mode;
418 
419 	dpi_config_lcd_manager(dpi);
420 
421 	mdelay(2);
422 
423 	r = dss_mgr_enable(&dpi->output);
424 	if (r)
425 		goto err_mgr_enable;
426 
427 	mutex_unlock(&dpi->lock);
428 
429 	return 0;
430 
431 err_mgr_enable:
432 err_set_mode:
433 	if (dpi->pll)
434 		dss_pll_disable(dpi->pll);
435 err_pll_init:
436 err_src_sel:
437 	dispc_runtime_put(dpi->dss->dispc);
438 err_get_dispc:
439 	if (dpi->vdds_dsi_reg)
440 		regulator_disable(dpi->vdds_dsi_reg);
441 err_reg_enable:
442 err_no_out_mgr:
443 	mutex_unlock(&dpi->lock);
444 	return r;
445 }
446 
447 static void dpi_display_disable(struct omap_dss_device *dssdev)
448 {
449 	struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
450 
451 	mutex_lock(&dpi->lock);
452 
453 	dss_mgr_disable(&dpi->output);
454 
455 	if (dpi->pll) {
456 		dss_select_lcd_clk_source(dpi->dss, dpi->output.dispc_channel,
457 					  DSS_CLK_SRC_FCK);
458 		dss_pll_disable(dpi->pll);
459 	}
460 
461 	dispc_runtime_put(dpi->dss->dispc);
462 
463 	if (dpi->vdds_dsi_reg)
464 		regulator_disable(dpi->vdds_dsi_reg);
465 
466 	mutex_unlock(&dpi->lock);
467 }
468 
469 static void dpi_set_timings(struct omap_dss_device *dssdev,
470 			    const struct videomode *vm)
471 {
472 	struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
473 
474 	DSSDBG("dpi_set_timings\n");
475 
476 	mutex_lock(&dpi->lock);
477 
478 	dpi->vm = *vm;
479 
480 	mutex_unlock(&dpi->lock);
481 }
482 
483 static int dpi_check_timings(struct omap_dss_device *dssdev,
484 			     struct videomode *vm)
485 {
486 	struct dpi_data *dpi = dpi_get_data_from_dssdev(dssdev);
487 	int lck_div, pck_div;
488 	unsigned long fck;
489 	unsigned long pck;
490 	struct dpi_clk_calc_ctx ctx;
491 	bool ok;
492 
493 	if (vm->hactive % 8 != 0)
494 		return -EINVAL;
495 
496 	if (vm->pixelclock == 0)
497 		return -EINVAL;
498 
499 	if (dpi->pll) {
500 		ok = dpi_pll_clk_calc(dpi, vm->pixelclock, &ctx);
501 		if (!ok)
502 			return -EINVAL;
503 
504 		fck = ctx.pll_cinfo.clkout[ctx.clkout_idx];
505 	} else {
506 		ok = dpi_dss_clk_calc(dpi, vm->pixelclock, &ctx);
507 		if (!ok)
508 			return -EINVAL;
509 
510 		fck = ctx.fck;
511 	}
512 
513 	lck_div = ctx.dispc_cinfo.lck_div;
514 	pck_div = ctx.dispc_cinfo.pck_div;
515 
516 	pck = fck / lck_div / pck_div;
517 
518 	vm->pixelclock = pck;
519 
520 	return 0;
521 }
522 
523 static int dpi_verify_pll(struct dss_pll *pll)
524 {
525 	int r;
526 
527 	/* do initial setup with the PLL to see if it is operational */
528 
529 	r = dss_pll_enable(pll);
530 	if (r)
531 		return r;
532 
533 	dss_pll_disable(pll);
534 
535 	return 0;
536 }
537 
538 static void dpi_init_pll(struct dpi_data *dpi)
539 {
540 	struct dss_pll *pll;
541 
542 	if (dpi->pll)
543 		return;
544 
545 	dpi->clk_src = dpi_get_clk_src(dpi);
546 
547 	pll = dss_pll_find_by_src(dpi->dss, dpi->clk_src);
548 	if (!pll)
549 		return;
550 
551 	if (dpi_verify_pll(pll)) {
552 		DSSWARN("PLL not operational\n");
553 		return;
554 	}
555 
556 	dpi->pll = pll;
557 }
558 
559 /*
560  * Return a hardcoded channel for the DPI output. This should work for
561  * current use cases, but this can be later expanded to either resolve
562  * the channel in some more dynamic manner, or get the channel as a user
563  * parameter.
564  */
565 static enum omap_channel dpi_get_channel(struct dpi_data *dpi)
566 {
567 	switch (dpi->dss_model) {
568 	case DSS_MODEL_OMAP2:
569 	case DSS_MODEL_OMAP3:
570 		return OMAP_DSS_CHANNEL_LCD;
571 
572 	case DSS_MODEL_DRA7:
573 		switch (dpi->id) {
574 		case 2:
575 			return OMAP_DSS_CHANNEL_LCD3;
576 		case 1:
577 			return OMAP_DSS_CHANNEL_LCD2;
578 		case 0:
579 		default:
580 			return OMAP_DSS_CHANNEL_LCD;
581 		}
582 
583 	case DSS_MODEL_OMAP4:
584 		return OMAP_DSS_CHANNEL_LCD2;
585 
586 	case DSS_MODEL_OMAP5:
587 		return OMAP_DSS_CHANNEL_LCD3;
588 
589 	default:
590 		DSSWARN("unsupported DSS version\n");
591 		return OMAP_DSS_CHANNEL_LCD;
592 	}
593 }
594 
595 static int dpi_connect(struct omap_dss_device *src,
596 		       struct omap_dss_device *dst)
597 {
598 	struct dpi_data *dpi = dpi_get_data_from_dssdev(dst);
599 	int r;
600 
601 	dpi_init_pll(dpi);
602 
603 	r = omapdss_device_connect(dst->dss, dst, dst->next);
604 	if (r)
605 		return r;
606 
607 	dst->dispc_channel_connected = true;
608 	return 0;
609 }
610 
611 static void dpi_disconnect(struct omap_dss_device *src,
612 			   struct omap_dss_device *dst)
613 {
614 	dst->dispc_channel_connected = false;
615 
616 	omapdss_device_disconnect(dst, dst->next);
617 }
618 
619 static const struct omap_dss_device_ops dpi_ops = {
620 	.connect = dpi_connect,
621 	.disconnect = dpi_disconnect,
622 
623 	.enable = dpi_display_enable,
624 	.disable = dpi_display_disable,
625 
626 	.check_timings = dpi_check_timings,
627 	.set_timings = dpi_set_timings,
628 };
629 
630 static int dpi_init_output_port(struct dpi_data *dpi, struct device_node *port)
631 {
632 	struct omap_dss_device *out = &dpi->output;
633 	u32 port_num = 0;
634 	int r;
635 
636 	of_property_read_u32(port, "reg", &port_num);
637 	dpi->id = port_num <= 2 ? port_num : 0;
638 
639 	switch (port_num) {
640 	case 2:
641 		out->name = "dpi.2";
642 		break;
643 	case 1:
644 		out->name = "dpi.1";
645 		break;
646 	case 0:
647 	default:
648 		out->name = "dpi.0";
649 		break;
650 	}
651 
652 	out->dev = &dpi->pdev->dev;
653 	out->id = OMAP_DSS_OUTPUT_DPI;
654 	out->output_type = OMAP_DISPLAY_TYPE_DPI;
655 	out->dispc_channel = dpi_get_channel(dpi);
656 	out->of_ports = BIT(port_num);
657 	out->ops = &dpi_ops;
658 	out->owner = THIS_MODULE;
659 
660 	out->next = omapdss_of_find_connected_device(out->dev->of_node, 0);
661 	if (IS_ERR(out->next)) {
662 		if (PTR_ERR(out->next) != -EPROBE_DEFER)
663 			dev_err(out->dev, "failed to find video sink\n");
664 		return PTR_ERR(out->next);
665 	}
666 
667 	r = omapdss_output_validate(out);
668 	if (r) {
669 		omapdss_device_put(out->next);
670 		out->next = NULL;
671 		return r;
672 	}
673 
674 	omapdss_device_register(out);
675 
676 	return 0;
677 }
678 
679 static void dpi_uninit_output_port(struct device_node *port)
680 {
681 	struct dpi_data *dpi = port->data;
682 	struct omap_dss_device *out = &dpi->output;
683 
684 	if (out->next)
685 		omapdss_device_put(out->next);
686 	omapdss_device_unregister(out);
687 }
688 
689 static const struct soc_device_attribute dpi_soc_devices[] = {
690 	{ .machine = "OMAP3[456]*" },
691 	{ .machine = "[AD]M37*" },
692 	{ /* sentinel */ }
693 };
694 
695 static int dpi_init_regulator(struct dpi_data *dpi)
696 {
697 	struct regulator *vdds_dsi;
698 
699 	/*
700 	 * The DPI uses the DSI VDDS on OMAP34xx, OMAP35xx, OMAP36xx, AM37xx and
701 	 * DM37xx only.
702 	 */
703 	if (!soc_device_match(dpi_soc_devices))
704 		return 0;
705 
706 	vdds_dsi = devm_regulator_get(&dpi->pdev->dev, "vdds_dsi");
707 	if (IS_ERR(vdds_dsi)) {
708 		if (PTR_ERR(vdds_dsi) != -EPROBE_DEFER)
709 			DSSERR("can't get VDDS_DSI regulator\n");
710 		return PTR_ERR(vdds_dsi);
711 	}
712 
713 	dpi->vdds_dsi_reg = vdds_dsi;
714 
715 	return 0;
716 }
717 
718 int dpi_init_port(struct dss_device *dss, struct platform_device *pdev,
719 		  struct device_node *port, enum dss_model dss_model)
720 {
721 	struct dpi_data *dpi;
722 	struct device_node *ep;
723 	u32 datalines;
724 	int r;
725 
726 	dpi = devm_kzalloc(&pdev->dev, sizeof(*dpi), GFP_KERNEL);
727 	if (!dpi)
728 		return -ENOMEM;
729 
730 	ep = of_get_next_child(port, NULL);
731 	if (!ep)
732 		return 0;
733 
734 	r = of_property_read_u32(ep, "data-lines", &datalines);
735 	of_node_put(ep);
736 	if (r) {
737 		DSSERR("failed to parse datalines\n");
738 		return r;
739 	}
740 
741 	dpi->data_lines = datalines;
742 
743 	dpi->pdev = pdev;
744 	dpi->dss_model = dss_model;
745 	dpi->dss = dss;
746 	port->data = dpi;
747 
748 	mutex_init(&dpi->lock);
749 
750 	r = dpi_init_regulator(dpi);
751 	if (r)
752 		return r;
753 
754 	return dpi_init_output_port(dpi, port);
755 }
756 
757 void dpi_uninit_port(struct device_node *port)
758 {
759 	struct dpi_data *dpi = port->data;
760 
761 	if (!dpi)
762 		return;
763 
764 	dpi_uninit_output_port(port);
765 }
766