xref: /rk3399_rockchip-uboot/drivers/video/tegra.c (revision f5acf91f6f956c81489db283d55ec83ab780e5a3)
1 /*
2  * Copyright (c) 2011 The Chromium OS Authors.
3  * SPDX-License-Identifier:	GPL-2.0+
4  */
5 
6 #include <common.h>
7 #include <dm.h>
8 #include <fdtdec.h>
9 #include <video.h>
10 #include <asm/system.h>
11 #include <asm/gpio.h>
12 #include <asm/io.h>
13 
14 #include <asm/arch/clock.h>
15 #include <asm/arch/funcmux.h>
16 #include <asm/arch/pinmux.h>
17 #include <asm/arch/pwm.h>
18 #include <asm/arch/display.h>
19 #include <asm/arch-tegra/timer.h>
20 
21 DECLARE_GLOBAL_DATA_PTR;
22 
23 /* These are the stages we go throuh in enabling the LCD */
24 enum stage_t {
25 	STAGE_START,
26 	STAGE_PANEL_VDD,
27 	STAGE_LVDS,
28 	STAGE_BACKLIGHT_VDD,
29 	STAGE_PWM,
30 	STAGE_BACKLIGHT_EN,
31 	STAGE_DONE,
32 };
33 
34 #define FDT_LCD_TIMINGS	4
35 
36 enum {
37 	FDT_LCD_TIMING_REF_TO_SYNC,
38 	FDT_LCD_TIMING_SYNC_WIDTH,
39 	FDT_LCD_TIMING_BACK_PORCH,
40 	FDT_LCD_TIMING_FRONT_PORCH,
41 
42 	FDT_LCD_TIMING_COUNT,
43 };
44 
45 enum lcd_cache_t {
46 	FDT_LCD_CACHE_OFF		= 0,
47 	FDT_LCD_CACHE_WRITE_THROUGH	= 1 << 0,
48 	FDT_LCD_CACHE_WRITE_BACK	= 1 << 1,
49 	FDT_LCD_CACHE_FLUSH		= 1 << 2,
50 	FDT_LCD_CACHE_WRITE_BACK_FLUSH	= FDT_LCD_CACHE_WRITE_BACK |
51 						FDT_LCD_CACHE_FLUSH,
52 };
53 
54 /* Information about the display controller */
55 struct tegra_lcd_priv {
56 	enum stage_t stage;	/* Current stage we are at */
57 	unsigned long timer_next; /* Time we can move onto next stage */
58 	int width;			/* width in pixels */
59 	int height;			/* height in pixels */
60 
61 	/*
62 	 * log2 of number of bpp, in general, unless it bpp is 24 in which
63 	 * case this field holds 24 also! This is a U-Boot thing.
64 	 */
65 	int log2_bpp;
66 	struct disp_ctlr *disp;		/* Display controller to use */
67 	fdt_addr_t frame_buffer;	/* Address of frame buffer */
68 	unsigned pixel_clock;		/* Pixel clock in Hz */
69 	uint horiz_timing[FDT_LCD_TIMING_COUNT];	/* Horizontal timing */
70 	uint vert_timing[FDT_LCD_TIMING_COUNT];		/* Vertical timing */
71 	int pwm_channel;		/* PWM channel to use for backlight */
72 	enum lcd_cache_t cache_type;
73 
74 	struct gpio_desc backlight_en;	/* GPIO for backlight enable */
75 	struct gpio_desc lvds_shutdown;	/* GPIO for lvds shutdown */
76 	struct gpio_desc backlight_vdd;	/* GPIO for backlight vdd */
77 	struct gpio_desc panel_vdd;	/* GPIO for panel vdd */
78 	/*
79 	 * Panel required timings
80 	 * Timing 1: delay between panel_vdd-rise and data-rise
81 	 * Timing 2: delay between data-rise and backlight_vdd-rise
82 	 * Timing 3: delay between backlight_vdd and pwm-rise
83 	 * Timing 4: delay between pwm-rise and backlight_en-rise
84 	 */
85 	uint panel_timings[FDT_LCD_TIMINGS];
86 };
87 
88 enum {
89 	/* Maximum LCD size we support */
90 	LCD_MAX_WIDTH		= 1366,
91 	LCD_MAX_HEIGHT		= 768,
92 	LCD_MAX_LOG2_BPP	= VIDEO_BPP16,
93 };
94 
95 static void update_window(struct dc_ctlr *dc, struct disp_ctl_win *win)
96 {
97 	unsigned h_dda, v_dda;
98 	unsigned long val;
99 
100 	val = readl(&dc->cmd.disp_win_header);
101 	val |= WINDOW_A_SELECT;
102 	writel(val, &dc->cmd.disp_win_header);
103 
104 	writel(win->fmt, &dc->win.color_depth);
105 
106 	clrsetbits_le32(&dc->win.byte_swap, BYTE_SWAP_MASK,
107 			BYTE_SWAP_NOSWAP << BYTE_SWAP_SHIFT);
108 
109 	val = win->out_x << H_POSITION_SHIFT;
110 	val |= win->out_y << V_POSITION_SHIFT;
111 	writel(val, &dc->win.pos);
112 
113 	val = win->out_w << H_SIZE_SHIFT;
114 	val |= win->out_h << V_SIZE_SHIFT;
115 	writel(val, &dc->win.size);
116 
117 	val = (win->w * win->bpp / 8) << H_PRESCALED_SIZE_SHIFT;
118 	val |= win->h << V_PRESCALED_SIZE_SHIFT;
119 	writel(val, &dc->win.prescaled_size);
120 
121 	writel(0, &dc->win.h_initial_dda);
122 	writel(0, &dc->win.v_initial_dda);
123 
124 	h_dda = (win->w * 0x1000) / max(win->out_w - 1, 1U);
125 	v_dda = (win->h * 0x1000) / max(win->out_h - 1, 1U);
126 
127 	val = h_dda << H_DDA_INC_SHIFT;
128 	val |= v_dda << V_DDA_INC_SHIFT;
129 	writel(val, &dc->win.dda_increment);
130 
131 	writel(win->stride, &dc->win.line_stride);
132 	writel(0, &dc->win.buf_stride);
133 
134 	val = WIN_ENABLE;
135 	if (win->bpp < 24)
136 		val |= COLOR_EXPAND;
137 	writel(val, &dc->win.win_opt);
138 
139 	writel((unsigned long)win->phys_addr, &dc->winbuf.start_addr);
140 	writel(win->x, &dc->winbuf.addr_h_offset);
141 	writel(win->y, &dc->winbuf.addr_v_offset);
142 
143 	writel(0xff00, &dc->win.blend_nokey);
144 	writel(0xff00, &dc->win.blend_1win);
145 
146 	val = GENERAL_ACT_REQ | WIN_A_ACT_REQ;
147 	val |= GENERAL_UPDATE | WIN_A_UPDATE;
148 	writel(val, &dc->cmd.state_ctrl);
149 }
150 
151 static void write_pair(struct tegra_lcd_priv *priv, int item, u32 *reg)
152 {
153 	writel(priv->horiz_timing[item] |
154 			(priv->vert_timing[item] << 16), reg);
155 }
156 
157 static int update_display_mode(struct dc_disp_reg *disp,
158 			       struct tegra_lcd_priv *priv)
159 {
160 	unsigned long val;
161 	unsigned long rate;
162 	unsigned long div;
163 
164 	writel(0x0, &disp->disp_timing_opt);
165 	write_pair(priv, FDT_LCD_TIMING_REF_TO_SYNC, &disp->ref_to_sync);
166 	write_pair(priv, FDT_LCD_TIMING_SYNC_WIDTH, &disp->sync_width);
167 	write_pair(priv, FDT_LCD_TIMING_BACK_PORCH, &disp->back_porch);
168 	write_pair(priv, FDT_LCD_TIMING_FRONT_PORCH, &disp->front_porch);
169 
170 	writel(priv->width | (priv->height << 16), &disp->disp_active);
171 
172 	val = DE_SELECT_ACTIVE << DE_SELECT_SHIFT;
173 	val |= DE_CONTROL_NORMAL << DE_CONTROL_SHIFT;
174 	writel(val, &disp->data_enable_opt);
175 
176 	val = DATA_FORMAT_DF1P1C << DATA_FORMAT_SHIFT;
177 	val |= DATA_ALIGNMENT_MSB << DATA_ALIGNMENT_SHIFT;
178 	val |= DATA_ORDER_RED_BLUE << DATA_ORDER_SHIFT;
179 	writel(val, &disp->disp_interface_ctrl);
180 
181 	/*
182 	 * The pixel clock divider is in 7.1 format (where the bottom bit
183 	 * represents 0.5). Here we calculate the divider needed to get from
184 	 * the display clock (typically 600MHz) to the pixel clock. We round
185 	 * up or down as requried.
186 	 */
187 	rate = clock_get_periph_rate(PERIPH_ID_DISP1, CLOCK_ID_CGENERAL);
188 	div = ((rate * 2 + priv->pixel_clock / 2) / priv->pixel_clock) - 2;
189 	debug("Display clock %lu, divider %lu\n", rate, div);
190 
191 	writel(0x00010001, &disp->shift_clk_opt);
192 
193 	val = PIXEL_CLK_DIVIDER_PCD1 << PIXEL_CLK_DIVIDER_SHIFT;
194 	val |= div << SHIFT_CLK_DIVIDER_SHIFT;
195 	writel(val, &disp->disp_clk_ctrl);
196 
197 	return 0;
198 }
199 
200 /* Start up the display and turn on power to PWMs */
201 static void basic_init(struct dc_cmd_reg *cmd)
202 {
203 	u32 val;
204 
205 	writel(0x00000100, &cmd->gen_incr_syncpt_ctrl);
206 	writel(0x0000011a, &cmd->cont_syncpt_vsync);
207 	writel(0x00000000, &cmd->int_type);
208 	writel(0x00000000, &cmd->int_polarity);
209 	writel(0x00000000, &cmd->int_mask);
210 	writel(0x00000000, &cmd->int_enb);
211 
212 	val = PW0_ENABLE | PW1_ENABLE | PW2_ENABLE;
213 	val |= PW3_ENABLE | PW4_ENABLE | PM0_ENABLE;
214 	val |= PM1_ENABLE;
215 	writel(val, &cmd->disp_pow_ctrl);
216 
217 	val = readl(&cmd->disp_cmd);
218 	val |= CTRL_MODE_C_DISPLAY << CTRL_MODE_SHIFT;
219 	writel(val, &cmd->disp_cmd);
220 }
221 
222 static void basic_init_timer(struct dc_disp_reg *disp)
223 {
224 	writel(0x00000020, &disp->mem_high_pri);
225 	writel(0x00000001, &disp->mem_high_pri_timer);
226 }
227 
228 static const u32 rgb_enb_tab[PIN_REG_COUNT] = {
229 	0x00000000,
230 	0x00000000,
231 	0x00000000,
232 	0x00000000,
233 };
234 
235 static const u32 rgb_polarity_tab[PIN_REG_COUNT] = {
236 	0x00000000,
237 	0x01000000,
238 	0x00000000,
239 	0x00000000,
240 };
241 
242 static const u32 rgb_data_tab[PIN_REG_COUNT] = {
243 	0x00000000,
244 	0x00000000,
245 	0x00000000,
246 	0x00000000,
247 };
248 
249 static const u32 rgb_sel_tab[PIN_OUTPUT_SEL_COUNT] = {
250 	0x00000000,
251 	0x00000000,
252 	0x00000000,
253 	0x00000000,
254 	0x00210222,
255 	0x00002200,
256 	0x00020000,
257 };
258 
259 static void rgb_enable(struct dc_com_reg *com)
260 {
261 	int i;
262 
263 	for (i = 0; i < PIN_REG_COUNT; i++) {
264 		writel(rgb_enb_tab[i], &com->pin_output_enb[i]);
265 		writel(rgb_polarity_tab[i], &com->pin_output_polarity[i]);
266 		writel(rgb_data_tab[i], &com->pin_output_data[i]);
267 	}
268 
269 	for (i = 0; i < PIN_OUTPUT_SEL_COUNT; i++)
270 		writel(rgb_sel_tab[i], &com->pin_output_sel[i]);
271 }
272 
273 static int setup_window(struct disp_ctl_win *win,
274 			struct tegra_lcd_priv *priv)
275 {
276 	win->x = 0;
277 	win->y = 0;
278 	win->w = priv->width;
279 	win->h = priv->height;
280 	win->out_x = 0;
281 	win->out_y = 0;
282 	win->out_w = priv->width;
283 	win->out_h = priv->height;
284 	win->phys_addr = priv->frame_buffer;
285 	win->stride = priv->width * (1 << priv->log2_bpp) / 8;
286 	debug("%s: depth = %d\n", __func__, priv->log2_bpp);
287 	switch (priv->log2_bpp) {
288 	case 5:
289 	case 24:
290 		win->fmt = COLOR_DEPTH_R8G8B8A8;
291 		win->bpp = 32;
292 		break;
293 	case 4:
294 		win->fmt = COLOR_DEPTH_B5G6R5;
295 		win->bpp = 16;
296 		break;
297 
298 	default:
299 		debug("Unsupported LCD bit depth");
300 		return -1;
301 	}
302 
303 	return 0;
304 }
305 
306 static void debug_timing(const char *name, unsigned int timing[])
307 {
308 #ifdef DEBUG
309 	int i;
310 
311 	debug("%s timing: ", name);
312 	for (i = 0; i < FDT_LCD_TIMING_COUNT; i++)
313 		debug("%d ", timing[i]);
314 	debug("\n");
315 #endif
316 }
317 
318 /**
319  * Register a new display based on device tree configuration.
320  *
321  * The frame buffer can be positioned by U-Boot or overriden by the fdt.
322  * You should pass in the U-Boot address here, and check the contents of
323  * struct tegra_lcd_priv to see what was actually chosen.
324  *
325  * @param blob			Device tree blob
326  * @param priv			Driver's private data
327  * @param default_lcd_base	Default address of LCD frame buffer
328  * @return 0 if ok, -1 on error (unsupported bits per pixel)
329  */
330 static int tegra_display_probe(const void *blob, struct tegra_lcd_priv *priv,
331 			       void *default_lcd_base)
332 {
333 	struct disp_ctl_win window;
334 	struct dc_ctlr *dc;
335 
336 	priv->frame_buffer = (u32)default_lcd_base;
337 
338 	dc = (struct dc_ctlr *)priv->disp;
339 
340 	/*
341 	 * A header file for clock constants was NAKed upstream.
342 	 * TODO: Put this into the FDT and fdt_lcd struct when we have clock
343 	 * support there
344 	 */
345 	clock_start_periph_pll(PERIPH_ID_HOST1X, CLOCK_ID_PERIPH,
346 			       144 * 1000000);
347 	clock_start_periph_pll(PERIPH_ID_DISP1, CLOCK_ID_CGENERAL,
348 			       600 * 1000000);
349 	basic_init(&dc->cmd);
350 	basic_init_timer(&dc->disp);
351 	rgb_enable(&dc->com);
352 
353 	if (priv->pixel_clock)
354 		update_display_mode(&dc->disp, priv);
355 
356 	if (setup_window(&window, priv))
357 		return -1;
358 
359 	update_window(dc, &window);
360 
361 	return 0;
362 }
363 
364 /**
365  * Handle the next stage of device init
366  */
367 static int handle_stage(const void *blob, struct tegra_lcd_priv *priv)
368 {
369 	debug("%s: stage %d\n", __func__, priv->stage);
370 
371 	/* do the things for this stage */
372 	switch (priv->stage) {
373 	case STAGE_START:
374 		/*
375 		 * It is possible that the FDT has requested that the LCD be
376 		 * disabled. We currently don't support this. It would require
377 		 * changes to U-Boot LCD subsystem to have LCD support
378 		 * compiled in but not used. An easier option might be to
379 		 * still have a frame buffer, but leave the backlight off and
380 		 * remove all mention of lcd in the stdout environment
381 		 * variable.
382 		 */
383 
384 		funcmux_select(PERIPH_ID_DISP1, FUNCMUX_DEFAULT);
385 		break;
386 	case STAGE_PANEL_VDD:
387 		if (dm_gpio_is_valid(&priv->panel_vdd))
388 			dm_gpio_set_value(&priv->panel_vdd, 1);
389 		break;
390 	case STAGE_LVDS:
391 		if (dm_gpio_is_valid(&priv->lvds_shutdown))
392 			dm_gpio_set_value(&priv->lvds_shutdown, 1);
393 		break;
394 	case STAGE_BACKLIGHT_VDD:
395 		if (dm_gpio_is_valid(&priv->backlight_vdd))
396 			dm_gpio_set_value(&priv->backlight_vdd, 1);
397 		break;
398 	case STAGE_PWM:
399 		/* Enable PWM at 15/16 high, 32768 Hz with divider 1 */
400 		pinmux_set_func(PMUX_PINGRP_GPU, PMUX_FUNC_PWM);
401 		pinmux_tristate_disable(PMUX_PINGRP_GPU);
402 
403 		pwm_enable(priv->pwm_channel, 32768, 0xdf, 1);
404 		break;
405 	case STAGE_BACKLIGHT_EN:
406 		if (dm_gpio_is_valid(&priv->backlight_en))
407 			dm_gpio_set_value(&priv->backlight_en, 1);
408 		break;
409 	case STAGE_DONE:
410 		break;
411 	}
412 
413 	/* set up timer for next stage */
414 	priv->timer_next = timer_get_us();
415 	if (priv->stage < FDT_LCD_TIMINGS)
416 		priv->timer_next += priv->panel_timings[priv->stage] * 1000;
417 
418 	/* move to next stage */
419 	priv->stage++;
420 	return 0;
421 }
422 
423 /**
424  * Perform the next stage of the LCD init if it is time to do so.
425  *
426  * LCD init can be time-consuming because of the number of delays we need
427  * while waiting for the backlight power supply, etc. This function can
428  * be called at various times during U-Boot operation to advance the
429  * initialization of the LCD to the next stage if sufficient time has
430  * passed since the last stage. It keeps track of what stage it is up to
431  * and the time that it is permitted to move to the next stage.
432  *
433  * The final call should have wait=1 to complete the init.
434  *
435  * @param blob	fdt blob containing LCD information
436  * @param wait	1 to wait until all init is complete, and then return
437  *		0 to return immediately, potentially doing nothing if it is
438  *		not yet time for the next init.
439  */
440 static int tegra_lcd_check_next_stage(const void *blob,
441 				      struct tegra_lcd_priv *priv, int wait)
442 {
443 	if (priv->stage == STAGE_DONE)
444 		return 0;
445 
446 	do {
447 		/* wait if we need to */
448 		debug("%s: stage %d\n", __func__, priv->stage);
449 		if (priv->stage != STAGE_START) {
450 			int delay = priv->timer_next - timer_get_us();
451 
452 			if (delay > 0) {
453 				if (wait)
454 					udelay(delay);
455 				else
456 					return 0;
457 			}
458 		}
459 
460 		if (handle_stage(blob, priv))
461 			return -1;
462 	} while (wait && priv->stage != STAGE_DONE);
463 	if (priv->stage == STAGE_DONE)
464 		debug("%s: LCD init complete\n", __func__);
465 
466 	return 0;
467 }
468 
469 static int tegra_lcd_probe(struct udevice *dev)
470 {
471 	struct video_uc_platdata *plat = dev_get_uclass_platdata(dev);
472 	struct video_priv *uc_priv = dev_get_uclass_priv(dev);
473 	struct tegra_lcd_priv *priv = dev_get_priv(dev);
474 	const void *blob = gd->fdt_blob;
475 	int type = DCACHE_OFF;
476 
477 	/* Initialize the Tegra display controller */
478 	if (tegra_display_probe(blob, priv, (void *)plat->base)) {
479 		printf("%s: Failed to probe display driver\n", __func__);
480 		return -1;
481 	}
482 
483 	tegra_lcd_check_next_stage(blob, priv, 1);
484 
485 	/* Set up the LCD caching as requested */
486 	if (priv->cache_type & FDT_LCD_CACHE_WRITE_THROUGH)
487 		type = DCACHE_WRITETHROUGH;
488 	else if (priv->cache_type & FDT_LCD_CACHE_WRITE_BACK)
489 		type = DCACHE_WRITEBACK;
490 	mmu_set_region_dcache_behaviour(priv->frame_buffer, plat->size, type);
491 
492 	/* Enable flushing after LCD writes if requested */
493 	video_set_flush_dcache(dev, priv->cache_type & FDT_LCD_CACHE_FLUSH);
494 
495 	uc_priv->xsize = priv->width;
496 	uc_priv->ysize = priv->height;
497 	uc_priv->bpix = priv->log2_bpp;
498 	debug("LCD frame buffer at %pa, size %x\n", &priv->frame_buffer,
499 	      plat->size);
500 
501 	return 0;
502 }
503 
504 static int tegra_lcd_ofdata_to_platdata(struct udevice *dev)
505 {
506 	struct tegra_lcd_priv *priv = dev_get_priv(dev);
507 	const void *blob = gd->fdt_blob;
508 	int node = dev->of_offset;
509 	int front, back, ref;
510 	int panel_node;
511 	int rgb;
512 	int bpp, bit;
513 
514 	priv->disp = (struct disp_ctlr *)dev_get_addr(dev);
515 	if (!priv->disp) {
516 		debug("%s: No display controller address\n", __func__);
517 		return -EINVAL;
518 	}
519 
520 	rgb = fdt_subnode_offset(blob, node, "rgb");
521 
522 	panel_node = fdtdec_lookup_phandle(blob, rgb, "nvidia,panel");
523 	if (panel_node < 0) {
524 		debug("%s: Cannot find panel information\n", __func__);
525 		return -EINVAL;
526 	}
527 
528 	priv->width = fdtdec_get_int(blob, panel_node, "xres", -1);
529 	priv->height = fdtdec_get_int(blob, panel_node, "yres", -1);
530 	priv->pixel_clock = fdtdec_get_int(blob, panel_node, "clock", 0);
531 	if (!priv->pixel_clock || priv->width == -1 || priv->height == -1) {
532 		debug("%s: Pixel parameters missing\n", __func__);
533 		return -EINVAL;
534 	}
535 
536 	back = fdtdec_get_int(blob, panel_node, "left-margin", -1);
537 	front = fdtdec_get_int(blob, panel_node, "right-margin", -1);
538 	ref = fdtdec_get_int(blob, panel_node, "hsync-len", -1);
539 	if ((back | front | ref) == -1) {
540 		debug("%s: Horizontal parameters missing\n", __func__);
541 		return -EINVAL;
542 	}
543 
544 	/* Use a ref-to-sync of 1 always, and take this from the front porch */
545 	priv->horiz_timing[FDT_LCD_TIMING_REF_TO_SYNC] = 1;
546 	priv->horiz_timing[FDT_LCD_TIMING_SYNC_WIDTH] = ref;
547 	priv->horiz_timing[FDT_LCD_TIMING_BACK_PORCH] = back;
548 	priv->horiz_timing[FDT_LCD_TIMING_FRONT_PORCH] = front -
549 		priv->horiz_timing[FDT_LCD_TIMING_REF_TO_SYNC];
550 	debug_timing("horiz", priv->horiz_timing);
551 
552 	back = fdtdec_get_int(blob, panel_node, "upper-margin", -1);
553 	front = fdtdec_get_int(blob, panel_node, "lower-margin", -1);
554 	ref = fdtdec_get_int(blob, panel_node, "vsync-len", -1);
555 	if ((back | front | ref) == -1) {
556 		debug("%s: Vertical parameters missing\n", __func__);
557 		return -EINVAL;
558 	}
559 
560 	priv->vert_timing[FDT_LCD_TIMING_REF_TO_SYNC] = 1;
561 	priv->vert_timing[FDT_LCD_TIMING_SYNC_WIDTH] = ref;
562 	priv->vert_timing[FDT_LCD_TIMING_BACK_PORCH] = back;
563 	priv->vert_timing[FDT_LCD_TIMING_FRONT_PORCH] = front -
564 		priv->vert_timing[FDT_LCD_TIMING_REF_TO_SYNC];
565 	debug_timing("vert", priv->vert_timing);
566 
567 	bpp = fdtdec_get_int(blob, panel_node, "nvidia,bits-per-pixel", -1);
568 	bit = ffs(bpp) - 1;
569 	if (bpp == (1 << bit))
570 		priv->log2_bpp = bit;
571 	else
572 		priv->log2_bpp = bpp;
573 	if (bpp == -1) {
574 		debug("%s: Pixel bpp parameters missing\n", __func__);
575 		return -EINVAL;
576 	}
577 
578 	priv->pwm_channel = pwm_request(blob, panel_node, "nvidia,pwm");
579 	if (priv->pwm_channel < 0) {
580 		debug("%s: Unable to request PWM channel\n", __func__);
581 		return -EINVAL;
582 	}
583 
584 	priv->cache_type = fdtdec_get_int(blob, panel_node, "nvidia,cache-type",
585 					  FDT_LCD_CACHE_WRITE_BACK_FLUSH);
586 
587 	/* These GPIOs are all optional */
588 	gpio_request_by_name_nodev(blob, panel_node,
589 				   "nvidia,backlight-enable-gpios", 0,
590 				   &priv->backlight_en, GPIOD_IS_OUT);
591 	gpio_request_by_name_nodev(blob, panel_node,
592 				   "nvidia,lvds-shutdown-gpios", 0,
593 				   &priv->lvds_shutdown, GPIOD_IS_OUT);
594 	gpio_request_by_name_nodev(blob, panel_node,
595 				   "nvidia,backlight-vdd-gpios", 0,
596 				   &priv->backlight_vdd, GPIOD_IS_OUT);
597 	gpio_request_by_name_nodev(blob, panel_node,
598 				   "nvidia,panel-vdd-gpios", 0,
599 				   &priv->panel_vdd, GPIOD_IS_OUT);
600 
601 	if (fdtdec_get_int_array(blob, panel_node, "nvidia,panel-timings",
602 				 priv->panel_timings, FDT_LCD_TIMINGS))
603 		return -EINVAL;
604 
605 	return 0;
606 }
607 
608 static int tegra_lcd_bind(struct udevice *dev)
609 {
610 	struct video_uc_platdata *plat = dev_get_uclass_platdata(dev);
611 
612 	plat->size = LCD_MAX_WIDTH * LCD_MAX_HEIGHT *
613 		(1 << LCD_MAX_LOG2_BPP) / 8;
614 
615 	return 0;
616 }
617 
618 static const struct video_ops tegra_lcd_ops = {
619 };
620 
621 static const struct udevice_id tegra_lcd_ids[] = {
622 	{ .compatible = "nvidia,tegra20-dc" },
623 	{ }
624 };
625 
626 U_BOOT_DRIVER(tegra_lcd) = {
627 	.name	= "tegra_lcd",
628 	.id	= UCLASS_VIDEO,
629 	.of_match = tegra_lcd_ids,
630 	.ops	= &tegra_lcd_ops,
631 	.bind	= tegra_lcd_bind,
632 	.probe	= tegra_lcd_probe,
633 	.ofdata_to_platdata	= tegra_lcd_ofdata_to_platdata,
634 	.priv_auto_alloc_size	= sizeof(struct tegra_lcd_priv),
635 };
636