xref: /linux/drivers/video/fbdev/imxfb.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Freescale i.MX Frame Buffer device driver
4  *
5  *  Copyright (C) 2004 Sascha Hauer, Pengutronix
6  *   Based on acornfb.c Copyright (C) Russell King.
7  *
8  * Please direct your questions and comments on this driver to the following
9  * email address:
10  *
11  *	linux-arm-kernel@lists.arm.linux.org.uk
12  */
13 
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/errno.h>
17 #include <linux/string.h>
18 #include <linux/interrupt.h>
19 #include <linux/slab.h>
20 #include <linux/mm.h>
21 #include <linux/fb.h>
22 #include <linux/delay.h>
23 #include <linux/init.h>
24 #include <linux/ioport.h>
25 #include <linux/cpufreq.h>
26 #include <linux/clk.h>
27 #include <linux/platform_device.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/io.h>
30 #include <linux/lcd.h>
31 #include <linux/math64.h>
32 #include <linux/of.h>
33 #include <linux/of_device.h>
34 #include <linux/bitfield.h>
35 
36 #include <linux/regulator/consumer.h>
37 
38 #include <video/of_display_timing.h>
39 #include <video/of_videomode.h>
40 #include <video/videomode.h>
41 
42 struct imx_fb_videomode {
43 	struct fb_videomode mode;
44 	u32 pcr;
45 	bool aus_mode;
46 	unsigned char	bpp;
47 };
48 
49 /*
50  * Complain if VAR is out of range.
51  */
52 #define DEBUG_VAR 1
53 
54 #define DRIVER_NAME "imx-fb"
55 
56 #define LCDC_SSA	0x00
57 
58 #define LCDC_SIZE	0x04
59 #define SIZE_XMAX_MASK	GENMASK(25, 20)
60 
61 #define YMAX_MASK_IMX1	GENMASK(8, 0)
62 #define YMAX_MASK_IMX21	GENMASK(9, 0)
63 
64 #define LCDC_VPW	0x08
65 #define VPW_VPW_MASK	GENMASK(9, 0)
66 
67 #define LCDC_CPOS	0x0C
68 #define CPOS_CC1	BIT(31)
69 #define CPOS_CC0	BIT(30)
70 #define CPOS_OP		BIT(28)
71 #define CPOS_CXP_MASK	GENMASK(25, 16)
72 
73 #define LCDC_LCWHB	0x10
74 #define LCWHB_BK_EN	BIT(31)
75 #define LCWHB_CW_MASK	GENMASK(28, 24)
76 #define LCWHB_CH_MASK	GENMASK(20, 16)
77 #define LCWHB_BD_MASK	GENMASK(7, 0)
78 
79 #define LCDC_LCHCC	0x14
80 
81 #define LCDC_PCR	0x18
82 #define PCR_TFT		BIT(31)
83 #define PCR_COLOR	BIT(30)
84 #define PCR_BPIX_MASK	GENMASK(27, 25)
85 #define PCR_BPIX_8	3
86 #define PCR_BPIX_12	4
87 #define PCR_BPIX_16	5
88 #define PCR_BPIX_18	6
89 #define PCR_PCD_MASK	GENMASK(5, 0)
90 
91 #define LCDC_HCR	0x1C
92 #define HCR_H_WIDTH_MASK	GENMASK(31, 26)
93 #define HCR_H_WAIT_1_MASK	GENMASK(15, 8)
94 #define HCR_H_WAIT_2_MASK	GENMASK(7, 0)
95 
96 #define LCDC_VCR	0x20
97 #define VCR_V_WIDTH_MASK	GENMASK(31, 26)
98 #define VCR_V_WAIT_1_MASK	GENMASK(15, 8)
99 #define VCR_V_WAIT_2_MASK	GENMASK(7, 0)
100 
101 #define LCDC_POS	0x24
102 #define POS_POS_MASK	GENMASK(4, 0)
103 
104 #define LCDC_LSCR1	0x28
105 /* bit fields in imxfb.h */
106 
107 #define LCDC_PWMR	0x2C
108 /* bit fields in imxfb.h */
109 
110 #define LCDC_DMACR	0x30
111 /* bit fields in imxfb.h */
112 
113 #define LCDC_RMCR	0x34
114 
115 #define RMCR_LCDC_EN_MX1	BIT(1)
116 
117 #define RMCR_SELF_REF	BIT(0)
118 
119 #define LCDC_LCDICR	0x38
120 #define LCDICR_INT_SYN	BIT(2)
121 #define LCDICR_INT_CON	BIT(0)
122 
123 #define LCDC_LCDISR	0x40
124 #define LCDISR_UDR_ERR	BIT(3)
125 #define LCDISR_ERR_RES	BIT(2)
126 #define LCDISR_EOF	BIT(1)
127 #define LCDISR_BOF	BIT(0)
128 
129 #define IMXFB_LSCR1_DEFAULT 0x00120300
130 
131 #define LCDC_LAUSCR	0x80
132 #define LAUSCR_AUS_MODE	BIT(31)
133 
134 /* Used fb-mode. Can be set on kernel command line, therefore file-static. */
135 static const char *fb_mode;
136 
137 /*
138  * These are the bitfields for each
139  * display depth that we support.
140  */
141 struct imxfb_rgb {
142 	struct fb_bitfield	red;
143 	struct fb_bitfield	green;
144 	struct fb_bitfield	blue;
145 	struct fb_bitfield	transp;
146 };
147 
148 enum imxfb_type {
149 	IMX1_FB,
150 	IMX21_FB,
151 };
152 
153 enum imxfb_panel_type {
154 	PANEL_TYPE_MONOCHROME,
155 	PANEL_TYPE_CSTN,
156 	PANEL_TYPE_TFT,
157 };
158 
159 struct imxfb_info {
160 	struct platform_device  *pdev;
161 	void __iomem		*regs;
162 	struct clk		*clk_ipg;
163 	struct clk		*clk_ahb;
164 	struct clk		*clk_per;
165 	enum imxfb_type		devtype;
166 	enum imxfb_panel_type	panel_type;
167 	bool			enabled;
168 
169 	/*
170 	 * These are the addresses we mapped
171 	 * the framebuffer memory region to.
172 	 */
173 	dma_addr_t		map_dma;
174 	u_int			map_size;
175 
176 	u_int			palette_size;
177 
178 	dma_addr_t		dbar1;
179 	dma_addr_t		dbar2;
180 
181 	u_int			pcr;
182 	u_int			lauscr;
183 	u_int			pwmr;
184 	u_int			lscr1;
185 	u_int			dmacr;
186 	bool			cmap_inverse;
187 	bool			cmap_static;
188 
189 	struct imx_fb_videomode *mode;
190 	int			num_modes;
191 
192 	struct regulator	*lcd_pwr;
193 	int			lcd_pwr_enabled;
194 };
195 
196 static const struct platform_device_id imxfb_devtype[] = {
197 	{
198 		.name = "imx1-fb",
199 		.driver_data = IMX1_FB,
200 	}, {
201 		.name = "imx21-fb",
202 		.driver_data = IMX21_FB,
203 	}, {
204 		/* sentinel */
205 	}
206 };
207 MODULE_DEVICE_TABLE(platform, imxfb_devtype);
208 
209 static const struct of_device_id imxfb_of_dev_id[] = {
210 	{
211 		.compatible = "fsl,imx1-fb",
212 		.data = &imxfb_devtype[IMX1_FB],
213 	}, {
214 		.compatible = "fsl,imx21-fb",
215 		.data = &imxfb_devtype[IMX21_FB],
216 	}, {
217 		/* sentinel */
218 	}
219 };
220 MODULE_DEVICE_TABLE(of, imxfb_of_dev_id);
221 
222 static inline int is_imx1_fb(struct imxfb_info *fbi)
223 {
224 	return fbi->devtype == IMX1_FB;
225 }
226 
227 #define IMX_NAME	"IMX"
228 
229 /*
230  * Minimum X and Y resolutions
231  */
232 #define MIN_XRES	64
233 #define MIN_YRES	64
234 
235 /* Actually this really is 18bit support, the lowest 2 bits of each colour
236  * are unused in hardware. We claim to have 24bit support to make software
237  * like X work, which does not support 18bit.
238  */
239 static struct imxfb_rgb def_rgb_18 = {
240 	.red	= {.offset = 16, .length = 8,},
241 	.green	= {.offset = 8, .length = 8,},
242 	.blue	= {.offset = 0, .length = 8,},
243 	.transp = {.offset = 0, .length = 0,},
244 };
245 
246 static struct imxfb_rgb def_rgb_16_tft = {
247 	.red	= {.offset = 11, .length = 5,},
248 	.green	= {.offset = 5, .length = 6,},
249 	.blue	= {.offset = 0, .length = 5,},
250 	.transp = {.offset = 0, .length = 0,},
251 };
252 
253 static struct imxfb_rgb def_rgb_16_stn = {
254 	.red	= {.offset = 8, .length = 4,},
255 	.green	= {.offset = 4, .length = 4,},
256 	.blue	= {.offset = 0, .length = 4,},
257 	.transp = {.offset = 0, .length = 0,},
258 };
259 
260 static struct imxfb_rgb def_rgb_8 = {
261 	.red	= {.offset = 0, .length = 8,},
262 	.green	= {.offset = 0, .length = 8,},
263 	.blue	= {.offset = 0, .length = 8,},
264 	.transp = {.offset = 0, .length = 0,},
265 };
266 
267 static int imxfb_activate_var(struct fb_var_screeninfo *var,
268 		struct fb_info *info);
269 
270 static inline u_int chan_to_field(u_int chan, struct fb_bitfield *bf)
271 {
272 	chan &= 0xffff;
273 	chan >>= 16 - bf->length;
274 	return chan << bf->offset;
275 }
276 
277 static int imxfb_setpalettereg(u_int regno, u_int red, u_int green, u_int blue,
278 		u_int trans, struct fb_info *info)
279 {
280 	struct imxfb_info *fbi = info->par;
281 	u_int val, ret = 1;
282 
283 #define CNVT_TOHW(val, width) ((((val)<<(width))+0x7FFF-(val))>>16)
284 	if (regno < fbi->palette_size) {
285 		val = (CNVT_TOHW(red, 4) << 8) |
286 		      (CNVT_TOHW(green, 4) << 4) |
287 		      CNVT_TOHW(blue,  4);
288 
289 		writel(val, fbi->regs + 0x800 + (regno << 2));
290 		ret = 0;
291 	}
292 	return ret;
293 }
294 
295 static int imxfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
296 		   u_int trans, struct fb_info *info)
297 {
298 	struct imxfb_info *fbi = info->par;
299 	unsigned int val;
300 	int ret = 1;
301 
302 	/*
303 	 * If inverse mode was selected, invert all the colours
304 	 * rather than the register number.  The register number
305 	 * is what you poke into the framebuffer to produce the
306 	 * colour you requested.
307 	 */
308 	if (fbi->cmap_inverse) {
309 		red   = 0xffff - red;
310 		green = 0xffff - green;
311 		blue  = 0xffff - blue;
312 	}
313 
314 	/*
315 	 * If greyscale is true, then we convert the RGB value
316 	 * to greyscale no mater what visual we are using.
317 	 */
318 	if (info->var.grayscale)
319 		red = green = blue = (19595 * red + 38470 * green +
320 					7471 * blue) >> 16;
321 
322 	switch (info->fix.visual) {
323 	case FB_VISUAL_TRUECOLOR:
324 		/*
325 		 * 12 or 16-bit True Colour.  We encode the RGB value
326 		 * according to the RGB bitfield information.
327 		 */
328 		if (regno < 16) {
329 			u32 *pal = info->pseudo_palette;
330 
331 			val  = chan_to_field(red, &info->var.red);
332 			val |= chan_to_field(green, &info->var.green);
333 			val |= chan_to_field(blue, &info->var.blue);
334 
335 			pal[regno] = val;
336 			ret = 0;
337 		}
338 		break;
339 
340 	case FB_VISUAL_STATIC_PSEUDOCOLOR:
341 	case FB_VISUAL_PSEUDOCOLOR:
342 		ret = imxfb_setpalettereg(regno, red, green, blue, trans, info);
343 		break;
344 	}
345 
346 	return ret;
347 }
348 
349 static const struct imx_fb_videomode *imxfb_find_mode(struct imxfb_info *fbi)
350 {
351 	struct imx_fb_videomode *m;
352 	int i;
353 
354 	if (!fb_mode)
355 		return &fbi->mode[0];
356 
357 	for (i = 0, m = &fbi->mode[0]; i < fbi->num_modes; i++, m++) {
358 		if (!strcmp(m->mode.name, fb_mode))
359 			return m;
360 	}
361 	return NULL;
362 }
363 
364 /*
365  *  imxfb_check_var():
366  *    Round up in the following order: bits_per_pixel, xres,
367  *    yres, xres_virtual, yres_virtual, xoffset, yoffset, grayscale,
368  *    bitfields, horizontal timing, vertical timing.
369  */
370 static int imxfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
371 {
372 	struct imxfb_info *fbi = info->par;
373 	struct imxfb_rgb *rgb;
374 	const struct imx_fb_videomode *imxfb_mode;
375 	unsigned long lcd_clk;
376 	unsigned long long tmp;
377 	u32 pcr = 0;
378 
379 	if (var->xres < MIN_XRES)
380 		var->xres = MIN_XRES;
381 	if (var->yres < MIN_YRES)
382 		var->yres = MIN_YRES;
383 
384 	imxfb_mode = imxfb_find_mode(fbi);
385 	if (!imxfb_mode)
386 		return -EINVAL;
387 
388 	var->xres		= imxfb_mode->mode.xres;
389 	var->yres		= imxfb_mode->mode.yres;
390 	var->bits_per_pixel	= imxfb_mode->bpp;
391 	var->pixclock		= imxfb_mode->mode.pixclock;
392 	var->hsync_len		= imxfb_mode->mode.hsync_len;
393 	var->left_margin	= imxfb_mode->mode.left_margin;
394 	var->right_margin	= imxfb_mode->mode.right_margin;
395 	var->vsync_len		= imxfb_mode->mode.vsync_len;
396 	var->upper_margin	= imxfb_mode->mode.upper_margin;
397 	var->lower_margin	= imxfb_mode->mode.lower_margin;
398 	var->sync		= imxfb_mode->mode.sync;
399 	var->xres_virtual	= max(var->xres_virtual, var->xres);
400 	var->yres_virtual	= max(var->yres_virtual, var->yres);
401 
402 	pr_debug("var->bits_per_pixel=%d\n", var->bits_per_pixel);
403 
404 	lcd_clk = clk_get_rate(fbi->clk_per);
405 
406 	tmp = var->pixclock * (unsigned long long)lcd_clk;
407 
408 	do_div(tmp, 1000000);
409 
410 	if (do_div(tmp, 1000000) > 500000)
411 		tmp++;
412 
413 	pcr = (unsigned int)tmp;
414 
415 	if (--pcr > PCR_PCD_MASK) {
416 		pcr = PCR_PCD_MASK;
417 		dev_warn(&fbi->pdev->dev, "Must limit pixel clock to %luHz\n",
418 			 lcd_clk / pcr);
419 	}
420 
421 	switch (var->bits_per_pixel) {
422 	case 32:
423 		pcr |= FIELD_PREP(PCR_BPIX_MASK, PCR_BPIX_18);
424 		rgb = &def_rgb_18;
425 		break;
426 	case 16:
427 	default:
428 		if (is_imx1_fb(fbi))
429 			pcr |= FIELD_PREP(PCR_BPIX_MASK, PCR_BPIX_12);
430 		else
431 			pcr |= FIELD_PREP(PCR_BPIX_MASK, PCR_BPIX_16);
432 
433 		if (imxfb_mode->pcr & PCR_TFT)
434 			rgb = &def_rgb_16_tft;
435 		else
436 			rgb = &def_rgb_16_stn;
437 		break;
438 	case 8:
439 		pcr |= FIELD_PREP(PCR_BPIX_MASK, PCR_BPIX_8);
440 		rgb = &def_rgb_8;
441 		break;
442 	}
443 
444 	/* add sync polarities */
445 	pcr |= imxfb_mode->pcr & ~(PCR_PCD_MASK | PCR_BPIX_MASK);
446 
447 	fbi->pcr = pcr;
448 	/*
449 	 * The LCDC AUS Mode Control Register does not exist on imx1.
450 	 */
451 	if (!is_imx1_fb(fbi) && imxfb_mode->aus_mode)
452 		fbi->lauscr = LAUSCR_AUS_MODE;
453 
454 	if (imxfb_mode->pcr & PCR_TFT)
455 		fbi->panel_type = PANEL_TYPE_TFT;
456 	else if (imxfb_mode->pcr & PCR_COLOR)
457 		fbi->panel_type = PANEL_TYPE_CSTN;
458 	else
459 		fbi->panel_type = PANEL_TYPE_MONOCHROME;
460 
461 	/*
462 	 * Copy the RGB parameters for this display
463 	 * from the machine specific parameters.
464 	 */
465 	var->red    = rgb->red;
466 	var->green  = rgb->green;
467 	var->blue   = rgb->blue;
468 	var->transp = rgb->transp;
469 
470 	pr_debug("RGBT length = %d:%d:%d:%d\n",
471 		var->red.length, var->green.length, var->blue.length,
472 		var->transp.length);
473 
474 	pr_debug("RGBT offset = %d:%d:%d:%d\n",
475 		var->red.offset, var->green.offset, var->blue.offset,
476 		var->transp.offset);
477 
478 	return 0;
479 }
480 
481 /*
482  * imxfb_set_par():
483  *	Set the user defined part of the display for the specified console
484  */
485 static int imxfb_set_par(struct fb_info *info)
486 {
487 	struct imxfb_info *fbi = info->par;
488 	struct fb_var_screeninfo *var = &info->var;
489 
490 	if (var->bits_per_pixel == 16 || var->bits_per_pixel == 32)
491 		info->fix.visual = FB_VISUAL_TRUECOLOR;
492 	else if (!fbi->cmap_static)
493 		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
494 	else {
495 		/*
496 		 * Some people have weird ideas about wanting static
497 		 * pseudocolor maps.  I suspect their user space
498 		 * applications are broken.
499 		 */
500 		info->fix.visual = FB_VISUAL_STATIC_PSEUDOCOLOR;
501 	}
502 
503 	info->fix.line_length = var->xres_virtual * var->bits_per_pixel / 8;
504 	fbi->palette_size = var->bits_per_pixel == 8 ? 256 : 16;
505 
506 	imxfb_activate_var(var, info);
507 
508 	return 0;
509 }
510 
511 static int imxfb_enable_controller(struct imxfb_info *fbi)
512 {
513 	int ret;
514 
515 	if (fbi->enabled)
516 		return 0;
517 
518 	pr_debug("Enabling LCD controller\n");
519 
520 	writel(fbi->map_dma, fbi->regs + LCDC_SSA);
521 
522 	/* panning offset 0 (0 pixel offset)        */
523 	writel(FIELD_PREP(POS_POS_MASK, 0), fbi->regs + LCDC_POS);
524 
525 	/* disable hardware cursor */
526 	writel(readl(fbi->regs + LCDC_CPOS) & ~(CPOS_CC0 | CPOS_CC1),
527 		fbi->regs + LCDC_CPOS);
528 
529 	/*
530 	 * RMCR_LCDC_EN_MX1 is present on i.MX1 only, but doesn't hurt
531 	 * on other SoCs
532 	 */
533 	writel(RMCR_LCDC_EN_MX1, fbi->regs + LCDC_RMCR);
534 
535 	ret = clk_prepare_enable(fbi->clk_ipg);
536 	if (ret)
537 		goto err_enable_ipg;
538 
539 	ret = clk_prepare_enable(fbi->clk_ahb);
540 	if (ret)
541 		goto err_enable_ahb;
542 
543 	ret = clk_prepare_enable(fbi->clk_per);
544 	if (ret)
545 		goto err_enable_per;
546 
547 	fbi->enabled = true;
548 	return 0;
549 
550 err_enable_per:
551 	clk_disable_unprepare(fbi->clk_ahb);
552 err_enable_ahb:
553 	clk_disable_unprepare(fbi->clk_ipg);
554 err_enable_ipg:
555 	writel(0, fbi->regs + LCDC_RMCR);
556 
557 	return ret;
558 }
559 
560 static void imxfb_disable_controller(struct imxfb_info *fbi)
561 {
562 	if (!fbi->enabled)
563 		return;
564 
565 	pr_debug("Disabling LCD controller\n");
566 
567 	clk_disable_unprepare(fbi->clk_per);
568 	clk_disable_unprepare(fbi->clk_ahb);
569 	clk_disable_unprepare(fbi->clk_ipg);
570 	fbi->enabled = false;
571 
572 	writel(0, fbi->regs + LCDC_RMCR);
573 }
574 
575 static int imxfb_blank(int blank, struct fb_info *info)
576 {
577 	struct imxfb_info *fbi = info->par;
578 
579 	pr_debug("%s: blank=%d\n", __func__, blank);
580 
581 	switch (blank) {
582 	case FB_BLANK_POWERDOWN:
583 	case FB_BLANK_VSYNC_SUSPEND:
584 	case FB_BLANK_HSYNC_SUSPEND:
585 	case FB_BLANK_NORMAL:
586 		imxfb_disable_controller(fbi);
587 		break;
588 
589 	case FB_BLANK_UNBLANK:
590 		return imxfb_enable_controller(fbi);
591 	}
592 	return 0;
593 }
594 
595 static const struct fb_ops imxfb_ops = {
596 	.owner		= THIS_MODULE,
597 	FB_DEFAULT_IOMEM_OPS,
598 	.fb_check_var	= imxfb_check_var,
599 	.fb_set_par	= imxfb_set_par,
600 	.fb_setcolreg	= imxfb_setcolreg,
601 	.fb_blank	= imxfb_blank,
602 };
603 
604 /*
605  * imxfb_activate_var():
606  *	Configures LCD Controller based on entries in var parameter.  Settings are
607  *	only written to the controller if changes were made.
608  */
609 static int imxfb_activate_var(struct fb_var_screeninfo *var, struct fb_info *info)
610 {
611 	struct imxfb_info *fbi = info->par;
612 	u32 ymax_mask = is_imx1_fb(fbi) ? YMAX_MASK_IMX1 : YMAX_MASK_IMX21;
613 	u8 left_margin_low;
614 
615 	pr_debug("var: xres=%d hslen=%d lm=%d rm=%d\n",
616 		var->xres, var->hsync_len,
617 		var->left_margin, var->right_margin);
618 	pr_debug("var: yres=%d vslen=%d um=%d bm=%d\n",
619 		var->yres, var->vsync_len,
620 		var->upper_margin, var->lower_margin);
621 
622 	if (fbi->panel_type == PANEL_TYPE_TFT)
623 		left_margin_low = 3;
624 	else if (fbi->panel_type == PANEL_TYPE_CSTN)
625 		left_margin_low = 2;
626 	else
627 		left_margin_low = 0;
628 
629 #if DEBUG_VAR
630 	if (var->xres < 16        || var->xres > 1024)
631 		dev_err(&fbi->pdev->dev, "%s: invalid xres %d\n",
632 			info->fix.id, var->xres);
633 	if (var->hsync_len < 1    || var->hsync_len > 64)
634 		dev_err(&fbi->pdev->dev, "%s: invalid hsync_len %d\n",
635 			info->fix.id, var->hsync_len);
636 	if (var->left_margin < left_margin_low  || var->left_margin > 255)
637 		dev_err(&fbi->pdev->dev, "%s: invalid left_margin %d\n",
638 			info->fix.id, var->left_margin);
639 	if (var->right_margin < 1 || var->right_margin > 255)
640 		dev_err(&fbi->pdev->dev, "%s: invalid right_margin %d\n",
641 			info->fix.id, var->right_margin);
642 	if (var->yres < 1 || var->yres > ymax_mask)
643 		dev_err(&fbi->pdev->dev, "%s: invalid yres %d\n",
644 			info->fix.id, var->yres);
645 	if (var->vsync_len > 100)
646 		dev_err(&fbi->pdev->dev, "%s: invalid vsync_len %d\n",
647 			info->fix.id, var->vsync_len);
648 	if (var->upper_margin > 63)
649 		dev_err(&fbi->pdev->dev, "%s: invalid upper_margin %d\n",
650 			info->fix.id, var->upper_margin);
651 	if (var->lower_margin > 255)
652 		dev_err(&fbi->pdev->dev, "%s: invalid lower_margin %d\n",
653 			info->fix.id, var->lower_margin);
654 #endif
655 
656 	/* physical screen start address	    */
657 	writel(FIELD_PREP(VPW_VPW_MASK,
658 			  var->xres * var->bits_per_pixel / 8 / 4),
659 	       fbi->regs + LCDC_VPW);
660 
661 	writel(FIELD_PREP(HCR_H_WIDTH_MASK, var->hsync_len - 1) |
662 	       FIELD_PREP(HCR_H_WAIT_1_MASK, var->right_margin - 1) |
663 	       FIELD_PREP(HCR_H_WAIT_2_MASK,
664 			  var->left_margin - left_margin_low),
665 	       fbi->regs + LCDC_HCR);
666 
667 	writel(FIELD_PREP(VCR_V_WIDTH_MASK, var->vsync_len) |
668 	       FIELD_PREP(VCR_V_WAIT_1_MASK, var->lower_margin) |
669 	       FIELD_PREP(VCR_V_WAIT_2_MASK, var->upper_margin),
670 	       fbi->regs + LCDC_VCR);
671 
672 	writel(FIELD_PREP(SIZE_XMAX_MASK, var->xres >> 4) |
673 	       (var->yres & ymax_mask),
674 	       fbi->regs + LCDC_SIZE);
675 
676 	writel(fbi->pcr, fbi->regs + LCDC_PCR);
677 	if (fbi->pwmr)
678 		writel(fbi->pwmr, fbi->regs + LCDC_PWMR);
679 	writel(fbi->lscr1, fbi->regs + LCDC_LSCR1);
680 
681 	/* dmacr = 0 is no valid value, as we need DMA control marks. */
682 	if (fbi->dmacr)
683 		writel(fbi->dmacr, fbi->regs + LCDC_DMACR);
684 
685 	if (fbi->lauscr)
686 		writel(fbi->lauscr, fbi->regs + LCDC_LAUSCR);
687 
688 	return 0;
689 }
690 
691 static int imxfb_init_fbinfo(struct platform_device *pdev)
692 {
693 	struct fb_info *info = platform_get_drvdata(pdev);
694 	struct imxfb_info *fbi = info->par;
695 	struct device_node *np;
696 
697 	info->pseudo_palette = devm_kmalloc_array(&pdev->dev, 16,
698 						  sizeof(u32), GFP_KERNEL);
699 	if (!info->pseudo_palette)
700 		return -ENOMEM;
701 
702 	memset(fbi, 0, sizeof(struct imxfb_info));
703 
704 	fbi->pdev = pdev;
705 	fbi->devtype = pdev->id_entry->driver_data;
706 
707 	strscpy(info->fix.id, IMX_NAME, sizeof(info->fix.id));
708 
709 	info->fix.type			= FB_TYPE_PACKED_PIXELS;
710 	info->fix.type_aux		= 0;
711 	info->fix.xpanstep		= 0;
712 	info->fix.ypanstep		= 0;
713 	info->fix.ywrapstep		= 0;
714 	info->fix.accel			= FB_ACCEL_NONE;
715 
716 	info->var.nonstd		= 0;
717 	info->var.activate		= FB_ACTIVATE_NOW;
718 	info->var.height		= -1;
719 	info->var.width	= -1;
720 	info->var.accel_flags		= 0;
721 	info->var.vmode			= FB_VMODE_NONINTERLACED;
722 
723 	info->fbops			= &imxfb_ops;
724 	info->flags			= FBINFO_READS_FAST;
725 
726 	np = pdev->dev.of_node;
727 	info->var.grayscale = of_property_read_bool(np,
728 					"cmap-greyscale");
729 	fbi->cmap_inverse = of_property_read_bool(np, "cmap-inverse");
730 	fbi->cmap_static = of_property_read_bool(np, "cmap-static");
731 
732 	fbi->lscr1 = IMXFB_LSCR1_DEFAULT;
733 
734 	of_property_read_u32(np, "fsl,lpccr", &fbi->pwmr);
735 
736 	of_property_read_u32(np, "fsl,lscr1", &fbi->lscr1);
737 
738 	of_property_read_u32(np, "fsl,dmacr", &fbi->dmacr);
739 
740 	return 0;
741 }
742 
743 static int imxfb_of_read_mode(struct device *dev, struct device_node *np,
744 		struct imx_fb_videomode *imxfb_mode)
745 {
746 	int ret;
747 	struct fb_videomode *of_mode = &imxfb_mode->mode;
748 	u32 bpp;
749 	u32 pcr;
750 
751 	ret = of_property_read_string(np, "model", &of_mode->name);
752 	if (ret)
753 		of_mode->name = NULL;
754 
755 	ret = of_get_fb_videomode(np, of_mode, OF_USE_NATIVE_MODE);
756 	if (ret) {
757 		dev_err(dev, "Failed to get videomode from DT\n");
758 		return ret;
759 	}
760 
761 	ret = of_property_read_u32(np, "bits-per-pixel", &bpp);
762 	ret |= of_property_read_u32(np, "fsl,pcr", &pcr);
763 
764 	if (ret) {
765 		dev_err(dev, "Failed to read bpp and pcr from DT\n");
766 		return -EINVAL;
767 	}
768 
769 	if (bpp < 1 || bpp > 255) {
770 		dev_err(dev, "Bits per pixel have to be between 1 and 255\n");
771 		return -EINVAL;
772 	}
773 
774 	imxfb_mode->bpp = bpp;
775 	imxfb_mode->pcr = pcr;
776 
777 	/*
778 	 * fsl,aus-mode is optional
779 	 */
780 	imxfb_mode->aus_mode = of_property_read_bool(np, "fsl,aus-mode");
781 
782 	return 0;
783 }
784 
785 static int imxfb_lcd_get_contrast(struct lcd_device *lcddev)
786 {
787 	struct imxfb_info *fbi = dev_get_drvdata(&lcddev->dev);
788 
789 	return fbi->pwmr & 0xff;
790 }
791 
792 static int imxfb_lcd_set_contrast(struct lcd_device *lcddev, int contrast)
793 {
794 	struct imxfb_info *fbi = dev_get_drvdata(&lcddev->dev);
795 
796 	if (fbi->pwmr && fbi->enabled) {
797 		if (contrast > 255)
798 			contrast = 255;
799 		else if (contrast < 0)
800 			contrast = 0;
801 
802 		fbi->pwmr &= ~0xff;
803 		fbi->pwmr |= contrast;
804 
805 		writel(fbi->pwmr, fbi->regs + LCDC_PWMR);
806 	}
807 
808 	return 0;
809 }
810 
811 static int imxfb_lcd_get_power(struct lcd_device *lcddev)
812 {
813 	struct imxfb_info *fbi = dev_get_drvdata(&lcddev->dev);
814 
815 	if (!IS_ERR(fbi->lcd_pwr) &&
816 	    !regulator_is_enabled(fbi->lcd_pwr))
817 		return LCD_POWER_OFF;
818 
819 	return LCD_POWER_ON;
820 }
821 
822 static int imxfb_regulator_set(struct imxfb_info *fbi, int enable)
823 {
824 	int ret;
825 
826 	if (enable == fbi->lcd_pwr_enabled)
827 		return 0;
828 
829 	if (enable)
830 		ret = regulator_enable(fbi->lcd_pwr);
831 	else
832 		ret = regulator_disable(fbi->lcd_pwr);
833 
834 	if (ret == 0)
835 		fbi->lcd_pwr_enabled = enable;
836 
837 	return ret;
838 }
839 
840 static int imxfb_lcd_set_power(struct lcd_device *lcddev, int power)
841 {
842 	struct imxfb_info *fbi = dev_get_drvdata(&lcddev->dev);
843 
844 	if (!IS_ERR(fbi->lcd_pwr))
845 		return imxfb_regulator_set(fbi, power == LCD_POWER_ON);
846 
847 	return 0;
848 }
849 
850 static const struct lcd_ops imxfb_lcd_ops = {
851 	.get_contrast	= imxfb_lcd_get_contrast,
852 	.set_contrast	= imxfb_lcd_set_contrast,
853 	.get_power	= imxfb_lcd_get_power,
854 	.set_power	= imxfb_lcd_set_power,
855 };
856 
857 static int imxfb_setup(void)
858 {
859 	char *opt, *options = NULL;
860 
861 	if (fb_get_options("imxfb", &options))
862 		return -ENODEV;
863 
864 	if (!options || !*options)
865 		return 0;
866 
867 	while ((opt = strsep(&options, ",")) != NULL) {
868 		if (!*opt)
869 			continue;
870 		else
871 			fb_mode = opt;
872 	}
873 
874 	return 0;
875 }
876 
877 static int imxfb_probe(struct platform_device *pdev)
878 {
879 	struct imxfb_info *fbi;
880 	struct lcd_device *lcd;
881 	struct fb_info *info;
882 	struct imx_fb_videomode *m;
883 	const struct of_device_id *of_id;
884 	struct device_node *display_np;
885 	int ret, i;
886 	int bytes_per_pixel;
887 
888 	dev_info(&pdev->dev, "i.MX Framebuffer driver\n");
889 
890 	ret = imxfb_setup();
891 	if (ret < 0)
892 		return ret;
893 
894 	of_id = of_match_device(imxfb_of_dev_id, &pdev->dev);
895 	if (of_id)
896 		pdev->id_entry = of_id->data;
897 
898 	info = framebuffer_alloc(sizeof(struct imxfb_info), &pdev->dev);
899 	if (!info)
900 		return -ENOMEM;
901 
902 	fbi = info->par;
903 
904 	platform_set_drvdata(pdev, info);
905 
906 	ret = imxfb_init_fbinfo(pdev);
907 	if (ret < 0)
908 		goto failed_init;
909 
910 	fb_mode = NULL;
911 
912 	display_np = of_parse_phandle(pdev->dev.of_node, "display", 0);
913 	if (!display_np) {
914 		dev_err(&pdev->dev, "No display defined in devicetree\n");
915 		ret = -EINVAL;
916 		goto failed_init;
917 	}
918 
919 	/*
920 	 * imxfb does not support more modes, we choose only the native
921 	 * mode.
922 	 */
923 	fbi->num_modes = 1;
924 
925 	fbi->mode = devm_kzalloc(&pdev->dev,
926 			sizeof(struct imx_fb_videomode), GFP_KERNEL);
927 	if (!fbi->mode) {
928 		ret = -ENOMEM;
929 		of_node_put(display_np);
930 		goto failed_init;
931 	}
932 
933 	ret = imxfb_of_read_mode(&pdev->dev, display_np, fbi->mode);
934 	of_node_put(display_np);
935 	if (ret)
936 		goto failed_init;
937 
938 	/*
939 	 * Calculate maximum bytes used per pixel. In most cases this should
940 	 * be the same as m->bpp/8
941 	 */
942 	m = &fbi->mode[0];
943 	bytes_per_pixel = (m->bpp + 7) / 8;
944 	for (i = 0; i < fbi->num_modes; i++, m++)
945 		info->fix.smem_len = max_t(size_t, info->fix.smem_len,
946 				m->mode.xres * m->mode.yres * bytes_per_pixel);
947 
948 	fbi->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
949 	if (IS_ERR(fbi->clk_ipg)) {
950 		ret = PTR_ERR(fbi->clk_ipg);
951 		goto failed_init;
952 	}
953 
954 	/*
955 	 * The LCDC controller does not have an enable bit. The
956 	 * controller starts directly when the clocks are enabled.
957 	 * If the clocks are enabled when the controller is not yet
958 	 * programmed with proper register values (enabled at the
959 	 * bootloader, for example) then it just goes into some undefined
960 	 * state.
961 	 * To avoid this issue, let's enable and disable LCDC IPG clock
962 	 * so that we force some kind of 'reset' to the LCDC block.
963 	 */
964 	ret = clk_prepare_enable(fbi->clk_ipg);
965 	if (ret)
966 		goto failed_init;
967 	clk_disable_unprepare(fbi->clk_ipg);
968 
969 	fbi->clk_ahb = devm_clk_get(&pdev->dev, "ahb");
970 	if (IS_ERR(fbi->clk_ahb)) {
971 		ret = PTR_ERR(fbi->clk_ahb);
972 		goto failed_init;
973 	}
974 
975 	fbi->clk_per = devm_clk_get(&pdev->dev, "per");
976 	if (IS_ERR(fbi->clk_per)) {
977 		ret = PTR_ERR(fbi->clk_per);
978 		goto failed_init;
979 	}
980 
981 	fbi->regs = devm_platform_ioremap_resource(pdev, 0);
982 	if (IS_ERR(fbi->regs)) {
983 		ret = PTR_ERR(fbi->regs);
984 		goto failed_init;
985 	}
986 
987 	fbi->map_size = PAGE_ALIGN(info->fix.smem_len);
988 	info->screen_buffer = dma_alloc_wc(&pdev->dev, fbi->map_size,
989 					   &fbi->map_dma, GFP_KERNEL);
990 	if (!info->screen_buffer) {
991 		dev_err(&pdev->dev, "Failed to allocate video RAM\n");
992 		ret = -ENOMEM;
993 		goto failed_init;
994 	}
995 
996 	info->fix.smem_start = fbi->map_dma;
997 
998 	INIT_LIST_HEAD(&info->modelist);
999 	for (i = 0; i < fbi->num_modes; i++)
1000 		fb_add_videomode(&fbi->mode[i].mode, &info->modelist);
1001 
1002 	/*
1003 	 * This makes sure that our colour bitfield
1004 	 * descriptors are correctly initialised.
1005 	 */
1006 	imxfb_check_var(&info->var, info);
1007 
1008 	/*
1009 	 * For modes > 8bpp, the color map is bypassed.
1010 	 * Therefore, 256 entries are enough.
1011 	 */
1012 	ret = fb_alloc_cmap(&info->cmap, 256, 0);
1013 	if (ret < 0)
1014 		goto failed_cmap;
1015 
1016 	imxfb_set_par(info);
1017 
1018 	fbi->lcd_pwr = devm_regulator_get(&pdev->dev, "lcd");
1019 	if (PTR_ERR(fbi->lcd_pwr) == -EPROBE_DEFER) {
1020 		ret = -EPROBE_DEFER;
1021 		goto failed_lcd;
1022 	}
1023 
1024 	lcd = devm_lcd_device_register(&pdev->dev, "imxfb-lcd", &pdev->dev, fbi,
1025 				       &imxfb_lcd_ops);
1026 	if (IS_ERR(lcd)) {
1027 		ret = PTR_ERR(lcd);
1028 		goto failed_lcd;
1029 	}
1030 
1031 	lcd->props.max_contrast = 0xff;
1032 
1033 	info->lcd_dev = lcd;
1034 
1035 	ret = register_framebuffer(info);
1036 	if (ret < 0) {
1037 		dev_err(&pdev->dev, "failed to register framebuffer\n");
1038 		goto failed_lcd;
1039 	}
1040 
1041 	imxfb_enable_controller(fbi);
1042 
1043 	return 0;
1044 
1045 failed_lcd:
1046 	fb_dealloc_cmap(&info->cmap);
1047 failed_cmap:
1048 	dma_free_wc(&pdev->dev, fbi->map_size, info->screen_buffer,
1049 		    fbi->map_dma);
1050 failed_init:
1051 	framebuffer_release(info);
1052 	return ret;
1053 }
1054 
1055 static void imxfb_remove(struct platform_device *pdev)
1056 {
1057 	struct fb_info *info = platform_get_drvdata(pdev);
1058 	struct imxfb_info *fbi = info->par;
1059 
1060 	imxfb_disable_controller(fbi);
1061 
1062 	unregister_framebuffer(info);
1063 	fb_dealloc_cmap(&info->cmap);
1064 	dma_free_wc(&pdev->dev, fbi->map_size, info->screen_buffer,
1065 		    fbi->map_dma);
1066 	framebuffer_release(info);
1067 }
1068 
1069 static int imxfb_suspend(struct device *dev)
1070 {
1071 	struct fb_info *info = dev_get_drvdata(dev);
1072 	struct imxfb_info *fbi = info->par;
1073 
1074 	imxfb_disable_controller(fbi);
1075 
1076 	return 0;
1077 }
1078 
1079 static int imxfb_resume(struct device *dev)
1080 {
1081 	struct fb_info *info = dev_get_drvdata(dev);
1082 	struct imxfb_info *fbi = info->par;
1083 
1084 	imxfb_enable_controller(fbi);
1085 
1086 	return 0;
1087 }
1088 
1089 static DEFINE_SIMPLE_DEV_PM_OPS(imxfb_pm_ops, imxfb_suspend, imxfb_resume);
1090 
1091 static struct platform_driver imxfb_driver = {
1092 	.driver		= {
1093 		.name	= DRIVER_NAME,
1094 		.of_match_table = imxfb_of_dev_id,
1095 		.pm	= pm_sleep_ptr(&imxfb_pm_ops),
1096 	},
1097 	.probe		= imxfb_probe,
1098 	.remove		= imxfb_remove,
1099 	.id_table	= imxfb_devtype,
1100 };
1101 module_platform_driver(imxfb_driver);
1102 
1103 MODULE_DESCRIPTION("Freescale i.MX framebuffer driver");
1104 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
1105 MODULE_LICENSE("GPL");
1106