xref: /openbmc/linux/drivers/video/fbdev/imxfb.c (revision 6db6b729)
1 /*
2  *  Freescale i.MX Frame Buffer device driver
3  *
4  *  Copyright (C) 2004 Sascha Hauer, Pengutronix
5  *   Based on acornfb.c Copyright (C) Russell King.
6  *
7  * This file is subject to the terms and conditions of the GNU General Public
8  * License.  See the file COPYING in the main directory of this archive for
9  * more details.
10  *
11  * Please direct your questions and comments on this driver to the following
12  * email address:
13  *
14  *	linux-arm-kernel@lists.arm.linux.org.uk
15  */
16 
17 #include <linux/module.h>
18 #include <linux/kernel.h>
19 #include <linux/errno.h>
20 #include <linux/string.h>
21 #include <linux/interrupt.h>
22 #include <linux/slab.h>
23 #include <linux/mm.h>
24 #include <linux/fb.h>
25 #include <linux/delay.h>
26 #include <linux/init.h>
27 #include <linux/ioport.h>
28 #include <linux/cpufreq.h>
29 #include <linux/clk.h>
30 #include <linux/platform_device.h>
31 #include <linux/dma-mapping.h>
32 #include <linux/io.h>
33 #include <linux/lcd.h>
34 #include <linux/math64.h>
35 #include <linux/of.h>
36 #include <linux/of_device.h>
37 
38 #include <linux/regulator/consumer.h>
39 
40 #include <video/of_display_timing.h>
41 #include <video/of_videomode.h>
42 #include <video/videomode.h>
43 
44 #define PCR_TFT		(1 << 31)
45 #define PCR_BPIX_8	(3 << 25)
46 #define PCR_BPIX_12	(4 << 25)
47 #define PCR_BPIX_16	(5 << 25)
48 #define PCR_BPIX_18	(6 << 25)
49 
50 struct imx_fb_videomode {
51 	struct fb_videomode mode;
52 	u32 pcr;
53 	bool aus_mode;
54 	unsigned char	bpp;
55 };
56 
57 /*
58  * Complain if VAR is out of range.
59  */
60 #define DEBUG_VAR 1
61 
62 #define DRIVER_NAME "imx-fb"
63 
64 #define LCDC_SSA	0x00
65 
66 #define LCDC_SIZE	0x04
67 #define SIZE_XMAX(x)	((((x) >> 4) & 0x3f) << 20)
68 
69 #define YMAX_MASK_IMX1	0x1ff
70 #define YMAX_MASK_IMX21	0x3ff
71 
72 #define LCDC_VPW	0x08
73 #define VPW_VPW(x)	((x) & 0x3ff)
74 
75 #define LCDC_CPOS	0x0C
76 #define CPOS_CC1	(1<<31)
77 #define CPOS_CC0	(1<<30)
78 #define CPOS_OP		(1<<28)
79 #define CPOS_CXP(x)	(((x) & 3ff) << 16)
80 
81 #define LCDC_LCWHB	0x10
82 #define LCWHB_BK_EN	(1<<31)
83 #define LCWHB_CW(w)	(((w) & 0x1f) << 24)
84 #define LCWHB_CH(h)	(((h) & 0x1f) << 16)
85 #define LCWHB_BD(x)	((x) & 0xff)
86 
87 #define LCDC_LCHCC	0x14
88 
89 #define LCDC_PCR	0x18
90 
91 #define LCDC_HCR	0x1C
92 #define HCR_H_WIDTH(x)	(((x) & 0x3f) << 26)
93 #define HCR_H_WAIT_1(x)	(((x) & 0xff) << 8)
94 #define HCR_H_WAIT_2(x)	((x) & 0xff)
95 
96 #define LCDC_VCR	0x20
97 #define VCR_V_WIDTH(x)	(((x) & 0x3f) << 26)
98 #define VCR_V_WAIT_1(x)	(((x) & 0xff) << 8)
99 #define VCR_V_WAIT_2(x)	((x) & 0xff)
100 
101 #define LCDC_POS	0x24
102 #define POS_POS(x)	((x) & 1f)
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	(1<<1)
116 
117 #define RMCR_SELF_REF	(1<<0)
118 
119 #define LCDC_LCDICR	0x38
120 #define LCDICR_INT_SYN	(1<<2)
121 #define LCDICR_INT_CON	(1)
122 
123 #define LCDC_LCDISR	0x40
124 #define LCDISR_UDR_ERR	(1<<3)
125 #define LCDISR_ERR_RES	(1<<2)
126 #define LCDISR_EOF	(1<<1)
127 #define LCDISR_BOF	(1<<0)
128 
129 #define IMXFB_LSCR1_DEFAULT 0x00120300
130 
131 #define LCDC_LAUSCR	0x80
132 #define LAUSCR_AUS_MODE	(1<<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 struct imxfb_info {
154 	struct platform_device  *pdev;
155 	void __iomem		*regs;
156 	struct clk		*clk_ipg;
157 	struct clk		*clk_ahb;
158 	struct clk		*clk_per;
159 	enum imxfb_type		devtype;
160 	bool			enabled;
161 
162 	/*
163 	 * These are the addresses we mapped
164 	 * the framebuffer memory region to.
165 	 */
166 	dma_addr_t		map_dma;
167 	u_int			map_size;
168 
169 	u_int			palette_size;
170 
171 	dma_addr_t		dbar1;
172 	dma_addr_t		dbar2;
173 
174 	u_int			pcr;
175 	u_int			lauscr;
176 	u_int			pwmr;
177 	u_int			lscr1;
178 	u_int			dmacr;
179 	bool			cmap_inverse;
180 	bool			cmap_static;
181 
182 	struct imx_fb_videomode *mode;
183 	int			num_modes;
184 
185 	struct regulator	*lcd_pwr;
186 	int			lcd_pwr_enabled;
187 };
188 
189 static const struct platform_device_id imxfb_devtype[] = {
190 	{
191 		.name = "imx1-fb",
192 		.driver_data = IMX1_FB,
193 	}, {
194 		.name = "imx21-fb",
195 		.driver_data = IMX21_FB,
196 	}, {
197 		/* sentinel */
198 	}
199 };
200 MODULE_DEVICE_TABLE(platform, imxfb_devtype);
201 
202 static const struct of_device_id imxfb_of_dev_id[] = {
203 	{
204 		.compatible = "fsl,imx1-fb",
205 		.data = &imxfb_devtype[IMX1_FB],
206 	}, {
207 		.compatible = "fsl,imx21-fb",
208 		.data = &imxfb_devtype[IMX21_FB],
209 	}, {
210 		/* sentinel */
211 	}
212 };
213 MODULE_DEVICE_TABLE(of, imxfb_of_dev_id);
214 
215 static inline int is_imx1_fb(struct imxfb_info *fbi)
216 {
217 	return fbi->devtype == IMX1_FB;
218 }
219 
220 #define IMX_NAME	"IMX"
221 
222 /*
223  * Minimum X and Y resolutions
224  */
225 #define MIN_XRES	64
226 #define MIN_YRES	64
227 
228 /* Actually this really is 18bit support, the lowest 2 bits of each colour
229  * are unused in hardware. We claim to have 24bit support to make software
230  * like X work, which does not support 18bit.
231  */
232 static struct imxfb_rgb def_rgb_18 = {
233 	.red	= {.offset = 16, .length = 8,},
234 	.green	= {.offset = 8, .length = 8,},
235 	.blue	= {.offset = 0, .length = 8,},
236 	.transp = {.offset = 0, .length = 0,},
237 };
238 
239 static struct imxfb_rgb def_rgb_16_tft = {
240 	.red	= {.offset = 11, .length = 5,},
241 	.green	= {.offset = 5, .length = 6,},
242 	.blue	= {.offset = 0, .length = 5,},
243 	.transp = {.offset = 0, .length = 0,},
244 };
245 
246 static struct imxfb_rgb def_rgb_16_stn = {
247 	.red	= {.offset = 8, .length = 4,},
248 	.green	= {.offset = 4, .length = 4,},
249 	.blue	= {.offset = 0, .length = 4,},
250 	.transp = {.offset = 0, .length = 0,},
251 };
252 
253 static struct imxfb_rgb def_rgb_8 = {
254 	.red	= {.offset = 0, .length = 8,},
255 	.green	= {.offset = 0, .length = 8,},
256 	.blue	= {.offset = 0, .length = 8,},
257 	.transp = {.offset = 0, .length = 0,},
258 };
259 
260 static int imxfb_activate_var(struct fb_var_screeninfo *var,
261 		struct fb_info *info);
262 
263 static inline u_int chan_to_field(u_int chan, struct fb_bitfield *bf)
264 {
265 	chan &= 0xffff;
266 	chan >>= 16 - bf->length;
267 	return chan << bf->offset;
268 }
269 
270 static int imxfb_setpalettereg(u_int regno, u_int red, u_int green, u_int blue,
271 		u_int trans, struct fb_info *info)
272 {
273 	struct imxfb_info *fbi = info->par;
274 	u_int val, ret = 1;
275 
276 #define CNVT_TOHW(val,width) ((((val)<<(width))+0x7FFF-(val))>>16)
277 	if (regno < fbi->palette_size) {
278 		val = (CNVT_TOHW(red, 4) << 8) |
279 		      (CNVT_TOHW(green,4) << 4) |
280 		      CNVT_TOHW(blue,  4);
281 
282 		writel(val, fbi->regs + 0x800 + (regno << 2));
283 		ret = 0;
284 	}
285 	return ret;
286 }
287 
288 static int imxfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
289 		   u_int trans, struct fb_info *info)
290 {
291 	struct imxfb_info *fbi = info->par;
292 	unsigned int val;
293 	int ret = 1;
294 
295 	/*
296 	 * If inverse mode was selected, invert all the colours
297 	 * rather than the register number.  The register number
298 	 * is what you poke into the framebuffer to produce the
299 	 * colour you requested.
300 	 */
301 	if (fbi->cmap_inverse) {
302 		red   = 0xffff - red;
303 		green = 0xffff - green;
304 		blue  = 0xffff - blue;
305 	}
306 
307 	/*
308 	 * If greyscale is true, then we convert the RGB value
309 	 * to greyscale no mater what visual we are using.
310 	 */
311 	if (info->var.grayscale)
312 		red = green = blue = (19595 * red + 38470 * green +
313 					7471 * blue) >> 16;
314 
315 	switch (info->fix.visual) {
316 	case FB_VISUAL_TRUECOLOR:
317 		/*
318 		 * 12 or 16-bit True Colour.  We encode the RGB value
319 		 * according to the RGB bitfield information.
320 		 */
321 		if (regno < 16) {
322 			u32 *pal = info->pseudo_palette;
323 
324 			val  = chan_to_field(red, &info->var.red);
325 			val |= chan_to_field(green, &info->var.green);
326 			val |= chan_to_field(blue, &info->var.blue);
327 
328 			pal[regno] = val;
329 			ret = 0;
330 		}
331 		break;
332 
333 	case FB_VISUAL_STATIC_PSEUDOCOLOR:
334 	case FB_VISUAL_PSEUDOCOLOR:
335 		ret = imxfb_setpalettereg(regno, red, green, blue, trans, info);
336 		break;
337 	}
338 
339 	return ret;
340 }
341 
342 static const struct imx_fb_videomode *imxfb_find_mode(struct imxfb_info *fbi)
343 {
344 	struct imx_fb_videomode *m;
345 	int i;
346 
347 	if (!fb_mode)
348 		return &fbi->mode[0];
349 
350 	for (i = 0, m = &fbi->mode[0]; i < fbi->num_modes; i++, m++) {
351 		if (!strcmp(m->mode.name, fb_mode))
352 			return m;
353 	}
354 	return NULL;
355 }
356 
357 /*
358  *  imxfb_check_var():
359  *    Round up in the following order: bits_per_pixel, xres,
360  *    yres, xres_virtual, yres_virtual, xoffset, yoffset, grayscale,
361  *    bitfields, horizontal timing, vertical timing.
362  */
363 static int imxfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
364 {
365 	struct imxfb_info *fbi = info->par;
366 	struct imxfb_rgb *rgb;
367 	const struct imx_fb_videomode *imxfb_mode;
368 	unsigned long lcd_clk;
369 	unsigned long long tmp;
370 	u32 pcr = 0;
371 
372 	if (var->xres < MIN_XRES)
373 		var->xres = MIN_XRES;
374 	if (var->yres < MIN_YRES)
375 		var->yres = MIN_YRES;
376 
377 	imxfb_mode = imxfb_find_mode(fbi);
378 	if (!imxfb_mode)
379 		return -EINVAL;
380 
381 	var->xres		= imxfb_mode->mode.xres;
382 	var->yres		= imxfb_mode->mode.yres;
383 	var->bits_per_pixel	= imxfb_mode->bpp;
384 	var->pixclock		= imxfb_mode->mode.pixclock;
385 	var->hsync_len		= imxfb_mode->mode.hsync_len;
386 	var->left_margin	= imxfb_mode->mode.left_margin;
387 	var->right_margin	= imxfb_mode->mode.right_margin;
388 	var->vsync_len		= imxfb_mode->mode.vsync_len;
389 	var->upper_margin	= imxfb_mode->mode.upper_margin;
390 	var->lower_margin	= imxfb_mode->mode.lower_margin;
391 	var->sync		= imxfb_mode->mode.sync;
392 	var->xres_virtual	= max(var->xres_virtual, var->xres);
393 	var->yres_virtual	= max(var->yres_virtual, var->yres);
394 
395 	pr_debug("var->bits_per_pixel=%d\n", var->bits_per_pixel);
396 
397 	lcd_clk = clk_get_rate(fbi->clk_per);
398 
399 	tmp = var->pixclock * (unsigned long long)lcd_clk;
400 
401 	do_div(tmp, 1000000);
402 
403 	if (do_div(tmp, 1000000) > 500000)
404 		tmp++;
405 
406 	pcr = (unsigned int)tmp;
407 
408 	if (--pcr > 0x3F) {
409 		pcr = 0x3F;
410 		printk(KERN_WARNING "Must limit pixel clock to %luHz\n",
411 				lcd_clk / pcr);
412 	}
413 
414 	switch (var->bits_per_pixel) {
415 	case 32:
416 		pcr |= PCR_BPIX_18;
417 		rgb = &def_rgb_18;
418 		break;
419 	case 16:
420 	default:
421 		if (is_imx1_fb(fbi))
422 			pcr |= PCR_BPIX_12;
423 		else
424 			pcr |= PCR_BPIX_16;
425 
426 		if (imxfb_mode->pcr & PCR_TFT)
427 			rgb = &def_rgb_16_tft;
428 		else
429 			rgb = &def_rgb_16_stn;
430 		break;
431 	case 8:
432 		pcr |= PCR_BPIX_8;
433 		rgb = &def_rgb_8;
434 		break;
435 	}
436 
437 	/* add sync polarities */
438 	pcr |= imxfb_mode->pcr & ~(0x3f | (7 << 25));
439 
440 	fbi->pcr = pcr;
441 	/*
442 	 * The LCDC AUS Mode Control Register does not exist on imx1.
443 	 */
444 	if (!is_imx1_fb(fbi) && imxfb_mode->aus_mode)
445 		fbi->lauscr = LAUSCR_AUS_MODE;
446 
447 	/*
448 	 * Copy the RGB parameters for this display
449 	 * from the machine specific parameters.
450 	 */
451 	var->red    = rgb->red;
452 	var->green  = rgb->green;
453 	var->blue   = rgb->blue;
454 	var->transp = rgb->transp;
455 
456 	pr_debug("RGBT length = %d:%d:%d:%d\n",
457 		var->red.length, var->green.length, var->blue.length,
458 		var->transp.length);
459 
460 	pr_debug("RGBT offset = %d:%d:%d:%d\n",
461 		var->red.offset, var->green.offset, var->blue.offset,
462 		var->transp.offset);
463 
464 	return 0;
465 }
466 
467 /*
468  * imxfb_set_par():
469  *	Set the user defined part of the display for the specified console
470  */
471 static int imxfb_set_par(struct fb_info *info)
472 {
473 	struct imxfb_info *fbi = info->par;
474 	struct fb_var_screeninfo *var = &info->var;
475 
476 	if (var->bits_per_pixel == 16 || var->bits_per_pixel == 32)
477 		info->fix.visual = FB_VISUAL_TRUECOLOR;
478 	else if (!fbi->cmap_static)
479 		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
480 	else {
481 		/*
482 		 * Some people have weird ideas about wanting static
483 		 * pseudocolor maps.  I suspect their user space
484 		 * applications are broken.
485 		 */
486 		info->fix.visual = FB_VISUAL_STATIC_PSEUDOCOLOR;
487 	}
488 
489 	info->fix.line_length = var->xres_virtual * var->bits_per_pixel / 8;
490 	fbi->palette_size = var->bits_per_pixel == 8 ? 256 : 16;
491 
492 	imxfb_activate_var(var, info);
493 
494 	return 0;
495 }
496 
497 static int imxfb_enable_controller(struct imxfb_info *fbi)
498 {
499 	int ret;
500 
501 	if (fbi->enabled)
502 		return 0;
503 
504 	pr_debug("Enabling LCD controller\n");
505 
506 	writel(fbi->map_dma, fbi->regs + LCDC_SSA);
507 
508 	/* panning offset 0 (0 pixel offset)        */
509 	writel(0x00000000, fbi->regs + LCDC_POS);
510 
511 	/* disable hardware cursor */
512 	writel(readl(fbi->regs + LCDC_CPOS) & ~(CPOS_CC0 | CPOS_CC1),
513 		fbi->regs + LCDC_CPOS);
514 
515 	/*
516 	 * RMCR_LCDC_EN_MX1 is present on i.MX1 only, but doesn't hurt
517 	 * on other SoCs
518 	 */
519 	writel(RMCR_LCDC_EN_MX1, fbi->regs + LCDC_RMCR);
520 
521 	ret = clk_prepare_enable(fbi->clk_ipg);
522 	if (ret)
523 		goto err_enable_ipg;
524 
525 	ret = clk_prepare_enable(fbi->clk_ahb);
526 	if (ret)
527 		goto err_enable_ahb;
528 
529 	ret = clk_prepare_enable(fbi->clk_per);
530 	if (ret)
531 		goto err_enable_per;
532 
533 	fbi->enabled = true;
534 	return 0;
535 
536 err_enable_per:
537 	clk_disable_unprepare(fbi->clk_ahb);
538 err_enable_ahb:
539 	clk_disable_unprepare(fbi->clk_ipg);
540 err_enable_ipg:
541 	writel(0, fbi->regs + LCDC_RMCR);
542 
543 	return ret;
544 }
545 
546 static void imxfb_disable_controller(struct imxfb_info *fbi)
547 {
548 	if (!fbi->enabled)
549 		return;
550 
551 	pr_debug("Disabling LCD controller\n");
552 
553 	clk_disable_unprepare(fbi->clk_per);
554 	clk_disable_unprepare(fbi->clk_ahb);
555 	clk_disable_unprepare(fbi->clk_ipg);
556 	fbi->enabled = false;
557 
558 	writel(0, fbi->regs + LCDC_RMCR);
559 }
560 
561 static int imxfb_blank(int blank, struct fb_info *info)
562 {
563 	struct imxfb_info *fbi = info->par;
564 
565 	pr_debug("imxfb_blank: blank=%d\n", blank);
566 
567 	switch (blank) {
568 	case FB_BLANK_POWERDOWN:
569 	case FB_BLANK_VSYNC_SUSPEND:
570 	case FB_BLANK_HSYNC_SUSPEND:
571 	case FB_BLANK_NORMAL:
572 		imxfb_disable_controller(fbi);
573 		break;
574 
575 	case FB_BLANK_UNBLANK:
576 		return imxfb_enable_controller(fbi);
577 	}
578 	return 0;
579 }
580 
581 static const struct fb_ops imxfb_ops = {
582 	.owner		= THIS_MODULE,
583 	FB_DEFAULT_IOMEM_OPS,
584 	.fb_check_var	= imxfb_check_var,
585 	.fb_set_par	= imxfb_set_par,
586 	.fb_setcolreg	= imxfb_setcolreg,
587 	.fb_blank	= imxfb_blank,
588 };
589 
590 /*
591  * imxfb_activate_var():
592  *	Configures LCD Controller based on entries in var parameter.  Settings are
593  *	only written to the controller if changes were made.
594  */
595 static int imxfb_activate_var(struct fb_var_screeninfo *var, struct fb_info *info)
596 {
597 	struct imxfb_info *fbi = info->par;
598 	u32 ymax_mask = is_imx1_fb(fbi) ? YMAX_MASK_IMX1 : YMAX_MASK_IMX21;
599 
600 	pr_debug("var: xres=%d hslen=%d lm=%d rm=%d\n",
601 		var->xres, var->hsync_len,
602 		var->left_margin, var->right_margin);
603 	pr_debug("var: yres=%d vslen=%d um=%d bm=%d\n",
604 		var->yres, var->vsync_len,
605 		var->upper_margin, var->lower_margin);
606 
607 #if DEBUG_VAR
608 	if (var->xres < 16        || var->xres > 1024)
609 		printk(KERN_ERR "%s: invalid xres %d\n",
610 			info->fix.id, var->xres);
611 	if (var->hsync_len < 1    || var->hsync_len > 64)
612 		printk(KERN_ERR "%s: invalid hsync_len %d\n",
613 			info->fix.id, var->hsync_len);
614 	if (var->left_margin < 3  || var->left_margin > 255)
615 		printk(KERN_ERR "%s: invalid left_margin %d\n",
616 			info->fix.id, var->left_margin);
617 	if (var->right_margin < 1 || var->right_margin > 255)
618 		printk(KERN_ERR "%s: invalid right_margin %d\n",
619 			info->fix.id, var->right_margin);
620 	if (var->yres < 1 || var->yres > ymax_mask)
621 		printk(KERN_ERR "%s: invalid yres %d\n",
622 			info->fix.id, var->yres);
623 	if (var->vsync_len > 100)
624 		printk(KERN_ERR "%s: invalid vsync_len %d\n",
625 			info->fix.id, var->vsync_len);
626 	if (var->upper_margin > 63)
627 		printk(KERN_ERR "%s: invalid upper_margin %d\n",
628 			info->fix.id, var->upper_margin);
629 	if (var->lower_margin > 255)
630 		printk(KERN_ERR "%s: invalid lower_margin %d\n",
631 			info->fix.id, var->lower_margin);
632 #endif
633 
634 	/* physical screen start address	    */
635 	writel(VPW_VPW(var->xres * var->bits_per_pixel / 8 / 4),
636 		fbi->regs + LCDC_VPW);
637 
638 	writel(HCR_H_WIDTH(var->hsync_len - 1) |
639 		HCR_H_WAIT_1(var->right_margin - 1) |
640 		HCR_H_WAIT_2(var->left_margin - 3),
641 		fbi->regs + LCDC_HCR);
642 
643 	writel(VCR_V_WIDTH(var->vsync_len) |
644 		VCR_V_WAIT_1(var->lower_margin) |
645 		VCR_V_WAIT_2(var->upper_margin),
646 		fbi->regs + LCDC_VCR);
647 
648 	writel(SIZE_XMAX(var->xres) | (var->yres & ymax_mask),
649 			fbi->regs + LCDC_SIZE);
650 
651 	writel(fbi->pcr, fbi->regs + LCDC_PCR);
652 	if (fbi->pwmr)
653 		writel(fbi->pwmr, fbi->regs + LCDC_PWMR);
654 	writel(fbi->lscr1, fbi->regs + LCDC_LSCR1);
655 
656 	/* dmacr = 0 is no valid value, as we need DMA control marks. */
657 	if (fbi->dmacr)
658 		writel(fbi->dmacr, fbi->regs + LCDC_DMACR);
659 
660 	if (fbi->lauscr)
661 		writel(fbi->lauscr, fbi->regs + LCDC_LAUSCR);
662 
663 	return 0;
664 }
665 
666 static int imxfb_init_fbinfo(struct platform_device *pdev)
667 {
668 	struct fb_info *info = platform_get_drvdata(pdev);
669 	struct imxfb_info *fbi = info->par;
670 	struct device_node *np;
671 
672 	pr_debug("%s\n",__func__);
673 
674 	info->pseudo_palette = devm_kmalloc_array(&pdev->dev, 16,
675 						  sizeof(u32), GFP_KERNEL);
676 	if (!info->pseudo_palette)
677 		return -ENOMEM;
678 
679 	memset(fbi, 0, sizeof(struct imxfb_info));
680 
681 	fbi->devtype = pdev->id_entry->driver_data;
682 
683 	strscpy(info->fix.id, IMX_NAME, sizeof(info->fix.id));
684 
685 	info->fix.type			= FB_TYPE_PACKED_PIXELS;
686 	info->fix.type_aux		= 0;
687 	info->fix.xpanstep		= 0;
688 	info->fix.ypanstep		= 0;
689 	info->fix.ywrapstep		= 0;
690 	info->fix.accel			= FB_ACCEL_NONE;
691 
692 	info->var.nonstd		= 0;
693 	info->var.activate		= FB_ACTIVATE_NOW;
694 	info->var.height		= -1;
695 	info->var.width	= -1;
696 	info->var.accel_flags		= 0;
697 	info->var.vmode			= FB_VMODE_NONINTERLACED;
698 
699 	info->fbops			= &imxfb_ops;
700 	info->flags			= FBINFO_READS_FAST;
701 
702 	np = pdev->dev.of_node;
703 	info->var.grayscale = of_property_read_bool(np,
704 					"cmap-greyscale");
705 	fbi->cmap_inverse = of_property_read_bool(np, "cmap-inverse");
706 	fbi->cmap_static = of_property_read_bool(np, "cmap-static");
707 
708 	fbi->lscr1 = IMXFB_LSCR1_DEFAULT;
709 
710 	of_property_read_u32(np, "fsl,lpccr", &fbi->pwmr);
711 
712 	of_property_read_u32(np, "fsl,lscr1", &fbi->lscr1);
713 
714 	of_property_read_u32(np, "fsl,dmacr", &fbi->dmacr);
715 
716 	return 0;
717 }
718 
719 static int imxfb_of_read_mode(struct device *dev, struct device_node *np,
720 		struct imx_fb_videomode *imxfb_mode)
721 {
722 	int ret;
723 	struct fb_videomode *of_mode = &imxfb_mode->mode;
724 	u32 bpp;
725 	u32 pcr;
726 
727 	ret = of_property_read_string(np, "model", &of_mode->name);
728 	if (ret)
729 		of_mode->name = NULL;
730 
731 	ret = of_get_fb_videomode(np, of_mode, OF_USE_NATIVE_MODE);
732 	if (ret) {
733 		dev_err(dev, "Failed to get videomode from DT\n");
734 		return ret;
735 	}
736 
737 	ret = of_property_read_u32(np, "bits-per-pixel", &bpp);
738 	ret |= of_property_read_u32(np, "fsl,pcr", &pcr);
739 
740 	if (ret) {
741 		dev_err(dev, "Failed to read bpp and pcr from DT\n");
742 		return -EINVAL;
743 	}
744 
745 	if (bpp < 1 || bpp > 255) {
746 		dev_err(dev, "Bits per pixel have to be between 1 and 255\n");
747 		return -EINVAL;
748 	}
749 
750 	imxfb_mode->bpp = bpp;
751 	imxfb_mode->pcr = pcr;
752 
753 	/*
754 	 * fsl,aus-mode is optional
755 	 */
756 	imxfb_mode->aus_mode = of_property_read_bool(np, "fsl,aus-mode");
757 
758 	return 0;
759 }
760 
761 static int imxfb_lcd_check_fb(struct lcd_device *lcddev, struct fb_info *fi)
762 {
763 	struct imxfb_info *fbi = dev_get_drvdata(&lcddev->dev);
764 
765 	if (!fi || fi->par == fbi)
766 		return 1;
767 
768 	return 0;
769 }
770 
771 static int imxfb_lcd_get_contrast(struct lcd_device *lcddev)
772 {
773 	struct imxfb_info *fbi = dev_get_drvdata(&lcddev->dev);
774 
775 	return fbi->pwmr & 0xff;
776 }
777 
778 static int imxfb_lcd_set_contrast(struct lcd_device *lcddev, int contrast)
779 {
780 	struct imxfb_info *fbi = dev_get_drvdata(&lcddev->dev);
781 
782 	if (fbi->pwmr && fbi->enabled) {
783 		if (contrast > 255)
784 			contrast = 255;
785 		else if (contrast < 0)
786 			contrast = 0;
787 
788 		fbi->pwmr &= ~0xff;
789 		fbi->pwmr |= contrast;
790 
791 		writel(fbi->pwmr, fbi->regs + LCDC_PWMR);
792 	}
793 
794 	return 0;
795 }
796 
797 static int imxfb_lcd_get_power(struct lcd_device *lcddev)
798 {
799 	struct imxfb_info *fbi = dev_get_drvdata(&lcddev->dev);
800 
801 	if (!IS_ERR(fbi->lcd_pwr) &&
802 	    !regulator_is_enabled(fbi->lcd_pwr))
803 		return FB_BLANK_POWERDOWN;
804 
805 	return FB_BLANK_UNBLANK;
806 }
807 
808 static int imxfb_regulator_set(struct imxfb_info *fbi, int enable)
809 {
810 	int ret;
811 
812 	if (enable == fbi->lcd_pwr_enabled)
813 		return 0;
814 
815 	if (enable)
816 		ret = regulator_enable(fbi->lcd_pwr);
817 	else
818 		ret = regulator_disable(fbi->lcd_pwr);
819 
820 	if (ret == 0)
821 		fbi->lcd_pwr_enabled = enable;
822 
823 	return ret;
824 }
825 
826 static int imxfb_lcd_set_power(struct lcd_device *lcddev, int power)
827 {
828 	struct imxfb_info *fbi = dev_get_drvdata(&lcddev->dev);
829 
830 	if (!IS_ERR(fbi->lcd_pwr))
831 		return imxfb_regulator_set(fbi, power == FB_BLANK_UNBLANK);
832 
833 	return 0;
834 }
835 
836 static struct lcd_ops imxfb_lcd_ops = {
837 	.check_fb	= imxfb_lcd_check_fb,
838 	.get_contrast	= imxfb_lcd_get_contrast,
839 	.set_contrast	= imxfb_lcd_set_contrast,
840 	.get_power	= imxfb_lcd_get_power,
841 	.set_power	= imxfb_lcd_set_power,
842 };
843 
844 static int imxfb_setup(void)
845 {
846 	char *opt, *options = NULL;
847 
848 	if (fb_get_options("imxfb", &options))
849 		return -ENODEV;
850 
851 	if (!options || !*options)
852 		return 0;
853 
854 	while ((opt = strsep(&options, ",")) != NULL) {
855 		if (!*opt)
856 			continue;
857 		else
858 			fb_mode = opt;
859 	}
860 
861 	return 0;
862 }
863 
864 static int imxfb_probe(struct platform_device *pdev)
865 {
866 	struct imxfb_info *fbi;
867 	struct lcd_device *lcd;
868 	struct fb_info *info;
869 	struct imx_fb_videomode *m;
870 	const struct of_device_id *of_id;
871 	struct device_node *display_np;
872 	int ret, i;
873 	int bytes_per_pixel;
874 
875 	dev_info(&pdev->dev, "i.MX Framebuffer driver\n");
876 
877 	ret = imxfb_setup();
878 	if (ret < 0)
879 		return ret;
880 
881 	of_id = of_match_device(imxfb_of_dev_id, &pdev->dev);
882 	if (of_id)
883 		pdev->id_entry = of_id->data;
884 
885 	info = framebuffer_alloc(sizeof(struct imxfb_info), &pdev->dev);
886 	if (!info)
887 		return -ENOMEM;
888 
889 	fbi = info->par;
890 
891 	platform_set_drvdata(pdev, info);
892 
893 	ret = imxfb_init_fbinfo(pdev);
894 	if (ret < 0)
895 		goto failed_init;
896 
897 	fb_mode = NULL;
898 
899 	display_np = of_parse_phandle(pdev->dev.of_node, "display", 0);
900 	if (!display_np) {
901 		dev_err(&pdev->dev, "No display defined in devicetree\n");
902 		ret = -EINVAL;
903 		goto failed_init;
904 	}
905 
906 	/*
907 	 * imxfb does not support more modes, we choose only the native
908 	 * mode.
909 	 */
910 	fbi->num_modes = 1;
911 
912 	fbi->mode = devm_kzalloc(&pdev->dev,
913 			sizeof(struct imx_fb_videomode), GFP_KERNEL);
914 	if (!fbi->mode) {
915 		ret = -ENOMEM;
916 		of_node_put(display_np);
917 		goto failed_init;
918 	}
919 
920 	ret = imxfb_of_read_mode(&pdev->dev, display_np, fbi->mode);
921 	of_node_put(display_np);
922 	if (ret)
923 		goto failed_init;
924 
925 	/* Calculate maximum bytes used per pixel. In most cases this should
926 	 * be the same as m->bpp/8 */
927 	m = &fbi->mode[0];
928 	bytes_per_pixel = (m->bpp + 7) / 8;
929 	for (i = 0; i < fbi->num_modes; i++, m++)
930 		info->fix.smem_len = max_t(size_t, info->fix.smem_len,
931 				m->mode.xres * m->mode.yres * bytes_per_pixel);
932 
933 	fbi->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
934 	if (IS_ERR(fbi->clk_ipg)) {
935 		ret = PTR_ERR(fbi->clk_ipg);
936 		goto failed_init;
937 	}
938 
939 	/*
940 	 * The LCDC controller does not have an enable bit. The
941 	 * controller starts directly when the clocks are enabled.
942 	 * If the clocks are enabled when the controller is not yet
943 	 * programmed with proper register values (enabled at the
944 	 * bootloader, for example) then it just goes into some undefined
945 	 * state.
946 	 * To avoid this issue, let's enable and disable LCDC IPG clock
947 	 * so that we force some kind of 'reset' to the LCDC block.
948 	 */
949 	ret = clk_prepare_enable(fbi->clk_ipg);
950 	if (ret)
951 		goto failed_init;
952 	clk_disable_unprepare(fbi->clk_ipg);
953 
954 	fbi->clk_ahb = devm_clk_get(&pdev->dev, "ahb");
955 	if (IS_ERR(fbi->clk_ahb)) {
956 		ret = PTR_ERR(fbi->clk_ahb);
957 		goto failed_init;
958 	}
959 
960 	fbi->clk_per = devm_clk_get(&pdev->dev, "per");
961 	if (IS_ERR(fbi->clk_per)) {
962 		ret = PTR_ERR(fbi->clk_per);
963 		goto failed_init;
964 	}
965 
966 	fbi->regs = devm_platform_ioremap_resource(pdev, 0);
967 	if (IS_ERR(fbi->regs)) {
968 		ret = PTR_ERR(fbi->regs);
969 		goto failed_init;
970 	}
971 
972 	fbi->map_size = PAGE_ALIGN(info->fix.smem_len);
973 	info->screen_buffer = dma_alloc_wc(&pdev->dev, fbi->map_size,
974 					   &fbi->map_dma, GFP_KERNEL);
975 	if (!info->screen_buffer) {
976 		dev_err(&pdev->dev, "Failed to allocate video RAM\n");
977 		ret = -ENOMEM;
978 		goto failed_init;
979 	}
980 
981 	info->fix.smem_start = fbi->map_dma;
982 
983 	INIT_LIST_HEAD(&info->modelist);
984 	for (i = 0; i < fbi->num_modes; i++)
985 		fb_add_videomode(&fbi->mode[i].mode, &info->modelist);
986 
987 	/*
988 	 * This makes sure that our colour bitfield
989 	 * descriptors are correctly initialised.
990 	 */
991 	imxfb_check_var(&info->var, info);
992 
993 	/*
994 	 * For modes > 8bpp, the color map is bypassed.
995 	 * Therefore, 256 entries are enough.
996 	 */
997 	ret = fb_alloc_cmap(&info->cmap, 256, 0);
998 	if (ret < 0)
999 		goto failed_cmap;
1000 
1001 	imxfb_set_par(info);
1002 	ret = register_framebuffer(info);
1003 	if (ret < 0) {
1004 		dev_err(&pdev->dev, "failed to register framebuffer\n");
1005 		goto failed_register;
1006 	}
1007 
1008 	fbi->lcd_pwr = devm_regulator_get(&pdev->dev, "lcd");
1009 	if (PTR_ERR(fbi->lcd_pwr) == -EPROBE_DEFER) {
1010 		ret = -EPROBE_DEFER;
1011 		goto failed_lcd;
1012 	}
1013 
1014 	lcd = devm_lcd_device_register(&pdev->dev, "imxfb-lcd", &pdev->dev, fbi,
1015 				       &imxfb_lcd_ops);
1016 	if (IS_ERR(lcd)) {
1017 		ret = PTR_ERR(lcd);
1018 		goto failed_lcd;
1019 	}
1020 
1021 	lcd->props.max_contrast = 0xff;
1022 
1023 	imxfb_enable_controller(fbi);
1024 	fbi->pdev = pdev;
1025 
1026 	return 0;
1027 
1028 failed_lcd:
1029 	unregister_framebuffer(info);
1030 failed_register:
1031 	fb_dealloc_cmap(&info->cmap);
1032 failed_cmap:
1033 	dma_free_wc(&pdev->dev, fbi->map_size, info->screen_buffer,
1034 		    fbi->map_dma);
1035 failed_init:
1036 	framebuffer_release(info);
1037 	return ret;
1038 }
1039 
1040 static void imxfb_remove(struct platform_device *pdev)
1041 {
1042 	struct fb_info *info = platform_get_drvdata(pdev);
1043 	struct imxfb_info *fbi = info->par;
1044 
1045 	imxfb_disable_controller(fbi);
1046 
1047 	unregister_framebuffer(info);
1048 	fb_dealloc_cmap(&info->cmap);
1049 	dma_free_wc(&pdev->dev, fbi->map_size, info->screen_buffer,
1050 		    fbi->map_dma);
1051 	framebuffer_release(info);
1052 }
1053 
1054 static int imxfb_suspend(struct device *dev)
1055 {
1056 	struct fb_info *info = dev_get_drvdata(dev);
1057 	struct imxfb_info *fbi = info->par;
1058 
1059 	imxfb_disable_controller(fbi);
1060 
1061 	return 0;
1062 }
1063 
1064 static int imxfb_resume(struct device *dev)
1065 {
1066 	struct fb_info *info = dev_get_drvdata(dev);
1067 	struct imxfb_info *fbi = info->par;
1068 
1069 	imxfb_enable_controller(fbi);
1070 
1071 	return 0;
1072 }
1073 
1074 static DEFINE_SIMPLE_DEV_PM_OPS(imxfb_pm_ops, imxfb_suspend, imxfb_resume);
1075 
1076 static struct platform_driver imxfb_driver = {
1077 	.driver		= {
1078 		.name	= DRIVER_NAME,
1079 		.of_match_table = imxfb_of_dev_id,
1080 		.pm	= pm_sleep_ptr(&imxfb_pm_ops),
1081 	},
1082 	.probe		= imxfb_probe,
1083 	.remove_new	= imxfb_remove,
1084 	.id_table	= imxfb_devtype,
1085 };
1086 module_platform_driver(imxfb_driver);
1087 
1088 MODULE_DESCRIPTION("Freescale i.MX framebuffer driver");
1089 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
1090 MODULE_LICENSE("GPL");
1091