xref: /openbmc/linux/drivers/video/fbdev/amba-clcd.c (revision de2bdb3d)
1 /*
2  *  linux/drivers/video/amba-clcd.c
3  *
4  * Copyright (C) 2001 ARM Limited, by David A Rusling
5  * Updated to 2.5, Deep Blue Solutions Ltd.
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
9  * for more details.
10  *
11  *  ARM PrimeCell PL110 Color LCD Controller
12  */
13 #include <linux/dma-mapping.h>
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/errno.h>
17 #include <linux/string.h>
18 #include <linux/slab.h>
19 #include <linux/delay.h>
20 #include <linux/mm.h>
21 #include <linux/fb.h>
22 #include <linux/init.h>
23 #include <linux/ioport.h>
24 #include <linux/list.h>
25 #include <linux/amba/bus.h>
26 #include <linux/amba/clcd.h>
27 #include <linux/bitops.h>
28 #include <linux/clk.h>
29 #include <linux/hardirq.h>
30 #include <linux/of.h>
31 #include <linux/of_address.h>
32 #include <linux/of_graph.h>
33 #include <linux/backlight.h>
34 #include <video/display_timing.h>
35 #include <video/of_display_timing.h>
36 #include <video/videomode.h>
37 
38 #include "amba-clcd-nomadik.h"
39 #include "amba-clcd-versatile.h"
40 
41 #define to_clcd(info)	container_of(info, struct clcd_fb, fb)
42 
43 /* This is limited to 16 characters when displayed by X startup */
44 static const char *clcd_name = "CLCD FB";
45 
46 /*
47  * Unfortunately, the enable/disable functions may be called either from
48  * process or IRQ context, and we _need_ to delay.  This is _not_ good.
49  */
50 static inline void clcdfb_sleep(unsigned int ms)
51 {
52 	if (in_atomic()) {
53 		mdelay(ms);
54 	} else {
55 		msleep(ms);
56 	}
57 }
58 
59 static inline void clcdfb_set_start(struct clcd_fb *fb)
60 {
61 	unsigned long ustart = fb->fb.fix.smem_start;
62 	unsigned long lstart;
63 
64 	ustart += fb->fb.var.yoffset * fb->fb.fix.line_length;
65 	lstart = ustart + fb->fb.var.yres * fb->fb.fix.line_length / 2;
66 
67 	writel(ustart, fb->regs + CLCD_UBAS);
68 	writel(lstart, fb->regs + CLCD_LBAS);
69 }
70 
71 static void clcdfb_disable(struct clcd_fb *fb)
72 {
73 	u32 val;
74 
75 	if (fb->board->disable)
76 		fb->board->disable(fb);
77 
78 	if (fb->panel->backlight) {
79 		fb->panel->backlight->props.power = FB_BLANK_POWERDOWN;
80 		backlight_update_status(fb->panel->backlight);
81 	}
82 
83 	val = readl(fb->regs + fb->off_cntl);
84 	if (val & CNTL_LCDPWR) {
85 		val &= ~CNTL_LCDPWR;
86 		writel(val, fb->regs + fb->off_cntl);
87 
88 		clcdfb_sleep(20);
89 	}
90 	if (val & CNTL_LCDEN) {
91 		val &= ~CNTL_LCDEN;
92 		writel(val, fb->regs + fb->off_cntl);
93 	}
94 
95 	/*
96 	 * Disable CLCD clock source.
97 	 */
98 	if (fb->clk_enabled) {
99 		fb->clk_enabled = false;
100 		clk_disable(fb->clk);
101 	}
102 }
103 
104 static void clcdfb_enable(struct clcd_fb *fb, u32 cntl)
105 {
106 	/*
107 	 * Enable the CLCD clock source.
108 	 */
109 	if (!fb->clk_enabled) {
110 		fb->clk_enabled = true;
111 		clk_enable(fb->clk);
112 	}
113 
114 	/*
115 	 * Bring up by first enabling..
116 	 */
117 	cntl |= CNTL_LCDEN;
118 	writel(cntl, fb->regs + fb->off_cntl);
119 
120 	clcdfb_sleep(20);
121 
122 	/*
123 	 * and now apply power.
124 	 */
125 	cntl |= CNTL_LCDPWR;
126 	writel(cntl, fb->regs + fb->off_cntl);
127 
128 	/*
129 	 * Turn on backlight
130 	 */
131 	if (fb->panel->backlight) {
132 		fb->panel->backlight->props.power = FB_BLANK_UNBLANK;
133 		backlight_update_status(fb->panel->backlight);
134 	}
135 
136 	/*
137 	 * finally, enable the interface.
138 	 */
139 	if (fb->board->enable)
140 		fb->board->enable(fb);
141 }
142 
143 static int
144 clcdfb_set_bitfields(struct clcd_fb *fb, struct fb_var_screeninfo *var)
145 {
146 	u32 caps;
147 	int ret = 0;
148 
149 	if (fb->panel->caps && fb->board->caps)
150 		caps = fb->panel->caps & fb->board->caps;
151 	else {
152 		/* Old way of specifying what can be used */
153 		caps = fb->panel->cntl & CNTL_BGR ?
154 			CLCD_CAP_BGR : CLCD_CAP_RGB;
155 		/* But mask out 444 modes as they weren't supported */
156 		caps &= ~CLCD_CAP_444;
157 	}
158 
159 	/* Only TFT panels can do RGB888/BGR888 */
160 	if (!(fb->panel->cntl & CNTL_LCDTFT))
161 		caps &= ~CLCD_CAP_888;
162 
163 	memset(&var->transp, 0, sizeof(var->transp));
164 
165 	var->red.msb_right = 0;
166 	var->green.msb_right = 0;
167 	var->blue.msb_right = 0;
168 
169 	switch (var->bits_per_pixel) {
170 	case 1:
171 	case 2:
172 	case 4:
173 	case 8:
174 		/* If we can't do 5551, reject */
175 		caps &= CLCD_CAP_5551;
176 		if (!caps) {
177 			ret = -EINVAL;
178 			break;
179 		}
180 
181 		var->red.length		= var->bits_per_pixel;
182 		var->red.offset		= 0;
183 		var->green.length	= var->bits_per_pixel;
184 		var->green.offset	= 0;
185 		var->blue.length	= var->bits_per_pixel;
186 		var->blue.offset	= 0;
187 		break;
188 
189 	case 16:
190 		/* If we can't do 444, 5551 or 565, reject */
191 		if (!(caps & (CLCD_CAP_444 | CLCD_CAP_5551 | CLCD_CAP_565))) {
192 			ret = -EINVAL;
193 			break;
194 		}
195 
196 		/*
197 		 * Green length can be 4, 5 or 6 depending whether
198 		 * we're operating in 444, 5551 or 565 mode.
199 		 */
200 		if (var->green.length == 4 && caps & CLCD_CAP_444)
201 			caps &= CLCD_CAP_444;
202 		if (var->green.length == 5 && caps & CLCD_CAP_5551)
203 			caps &= CLCD_CAP_5551;
204 		else if (var->green.length == 6 && caps & CLCD_CAP_565)
205 			caps &= CLCD_CAP_565;
206 		else {
207 			/*
208 			 * PL110 officially only supports RGB555,
209 			 * but may be wired up to allow RGB565.
210 			 */
211 			if (caps & CLCD_CAP_565) {
212 				var->green.length = 6;
213 				caps &= CLCD_CAP_565;
214 			} else if (caps & CLCD_CAP_5551) {
215 				var->green.length = 5;
216 				caps &= CLCD_CAP_5551;
217 			} else {
218 				var->green.length = 4;
219 				caps &= CLCD_CAP_444;
220 			}
221 		}
222 
223 		if (var->green.length >= 5) {
224 			var->red.length = 5;
225 			var->blue.length = 5;
226 		} else {
227 			var->red.length = 4;
228 			var->blue.length = 4;
229 		}
230 		break;
231 	case 24:
232 		if (fb->vendor->packed_24_bit_pixels) {
233 			var->red.length = 8;
234 			var->green.length = 8;
235 			var->blue.length = 8;
236 		} else {
237 			ret = -EINVAL;
238 		}
239 		break;
240 	case 32:
241 		/* If we can't do 888, reject */
242 		caps &= CLCD_CAP_888;
243 		if (!caps) {
244 			ret = -EINVAL;
245 			break;
246 		}
247 
248 		var->red.length = 8;
249 		var->green.length = 8;
250 		var->blue.length = 8;
251 		break;
252 	default:
253 		ret = -EINVAL;
254 		break;
255 	}
256 
257 	/*
258 	 * >= 16bpp displays have separate colour component bitfields
259 	 * encoded in the pixel data.  Calculate their position from
260 	 * the bitfield length defined above.
261 	 */
262 	if (ret == 0 && var->bits_per_pixel >= 16) {
263 		bool bgr, rgb;
264 
265 		bgr = caps & CLCD_CAP_BGR && var->blue.offset == 0;
266 		rgb = caps & CLCD_CAP_RGB && var->red.offset == 0;
267 
268 		if (!bgr && !rgb)
269 			/*
270 			 * The requested format was not possible, try just
271 			 * our capabilities.  One of BGR or RGB must be
272 			 * supported.
273 			 */
274 			bgr = caps & CLCD_CAP_BGR;
275 
276 		if (bgr) {
277 			var->blue.offset = 0;
278 			var->green.offset = var->blue.offset + var->blue.length;
279 			var->red.offset = var->green.offset + var->green.length;
280 		} else {
281 			var->red.offset = 0;
282 			var->green.offset = var->red.offset + var->red.length;
283 			var->blue.offset = var->green.offset + var->green.length;
284 		}
285 	}
286 
287 	return ret;
288 }
289 
290 static int clcdfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
291 {
292 	struct clcd_fb *fb = to_clcd(info);
293 	int ret = -EINVAL;
294 
295 	if (fb->board->check)
296 		ret = fb->board->check(fb, var);
297 
298 	if (ret == 0 &&
299 	    var->xres_virtual * var->bits_per_pixel / 8 *
300 	    var->yres_virtual > fb->fb.fix.smem_len)
301 		ret = -EINVAL;
302 
303 	if (ret == 0)
304 		ret = clcdfb_set_bitfields(fb, var);
305 
306 	return ret;
307 }
308 
309 static int clcdfb_set_par(struct fb_info *info)
310 {
311 	struct clcd_fb *fb = to_clcd(info);
312 	struct clcd_regs regs;
313 
314 	fb->fb.fix.line_length = fb->fb.var.xres_virtual *
315 				 fb->fb.var.bits_per_pixel / 8;
316 
317 	if (fb->fb.var.bits_per_pixel <= 8)
318 		fb->fb.fix.visual = FB_VISUAL_PSEUDOCOLOR;
319 	else
320 		fb->fb.fix.visual = FB_VISUAL_TRUECOLOR;
321 
322 	fb->board->decode(fb, &regs);
323 
324 	clcdfb_disable(fb);
325 
326 	/* Some variants must be clocked here */
327 	if (fb->vendor->clock_timregs && !fb->clk_enabled) {
328 		fb->clk_enabled = true;
329 		clk_enable(fb->clk);
330 	}
331 
332 	writel(regs.tim0, fb->regs + CLCD_TIM0);
333 	writel(regs.tim1, fb->regs + CLCD_TIM1);
334 	writel(regs.tim2, fb->regs + CLCD_TIM2);
335 	writel(regs.tim3, fb->regs + CLCD_TIM3);
336 
337 	clcdfb_set_start(fb);
338 
339 	clk_set_rate(fb->clk, (1000000000 / regs.pixclock) * 1000);
340 
341 	fb->clcd_cntl = regs.cntl;
342 
343 	clcdfb_enable(fb, regs.cntl);
344 
345 #ifdef DEBUG
346 	printk(KERN_INFO
347 	       "CLCD: Registers set to\n"
348 	       "  %08x %08x %08x %08x\n"
349 	       "  %08x %08x %08x %08x\n",
350 		readl(fb->regs + CLCD_TIM0), readl(fb->regs + CLCD_TIM1),
351 		readl(fb->regs + CLCD_TIM2), readl(fb->regs + CLCD_TIM3),
352 		readl(fb->regs + CLCD_UBAS), readl(fb->regs + CLCD_LBAS),
353 		readl(fb->regs + fb->off_ienb), readl(fb->regs + fb->off_cntl));
354 #endif
355 
356 	return 0;
357 }
358 
359 static inline u32 convert_bitfield(int val, struct fb_bitfield *bf)
360 {
361 	unsigned int mask = (1 << bf->length) - 1;
362 
363 	return (val >> (16 - bf->length) & mask) << bf->offset;
364 }
365 
366 /*
367  *  Set a single color register. The values supplied have a 16 bit
368  *  magnitude.  Return != 0 for invalid regno.
369  */
370 static int
371 clcdfb_setcolreg(unsigned int regno, unsigned int red, unsigned int green,
372 		 unsigned int blue, unsigned int transp, struct fb_info *info)
373 {
374 	struct clcd_fb *fb = to_clcd(info);
375 
376 	if (regno < 16)
377 		fb->cmap[regno] = convert_bitfield(transp, &fb->fb.var.transp) |
378 				  convert_bitfield(blue, &fb->fb.var.blue) |
379 				  convert_bitfield(green, &fb->fb.var.green) |
380 				  convert_bitfield(red, &fb->fb.var.red);
381 
382 	if (fb->fb.fix.visual == FB_VISUAL_PSEUDOCOLOR && regno < 256) {
383 		int hw_reg = CLCD_PALETTE + ((regno * 2) & ~3);
384 		u32 val, mask, newval;
385 
386 		newval  = (red >> 11)  & 0x001f;
387 		newval |= (green >> 6) & 0x03e0;
388 		newval |= (blue >> 1)  & 0x7c00;
389 
390 		/*
391 		 * 3.2.11: if we're configured for big endian
392 		 * byte order, the palette entries are swapped.
393 		 */
394 		if (fb->clcd_cntl & CNTL_BEBO)
395 			regno ^= 1;
396 
397 		if (regno & 1) {
398 			newval <<= 16;
399 			mask = 0x0000ffff;
400 		} else {
401 			mask = 0xffff0000;
402 		}
403 
404 		val = readl(fb->regs + hw_reg) & mask;
405 		writel(val | newval, fb->regs + hw_reg);
406 	}
407 
408 	return regno > 255;
409 }
410 
411 /*
412  *  Blank the screen if blank_mode != 0, else unblank. If blank == NULL
413  *  then the caller blanks by setting the CLUT (Color Look Up Table) to all
414  *  black. Return 0 if blanking succeeded, != 0 if un-/blanking failed due
415  *  to e.g. a video mode which doesn't support it. Implements VESA suspend
416  *  and powerdown modes on hardware that supports disabling hsync/vsync:
417  *    blank_mode == 2: suspend vsync
418  *    blank_mode == 3: suspend hsync
419  *    blank_mode == 4: powerdown
420  */
421 static int clcdfb_blank(int blank_mode, struct fb_info *info)
422 {
423 	struct clcd_fb *fb = to_clcd(info);
424 
425 	if (blank_mode != 0) {
426 		clcdfb_disable(fb);
427 	} else {
428 		clcdfb_enable(fb, fb->clcd_cntl);
429 	}
430 	return 0;
431 }
432 
433 static int clcdfb_mmap(struct fb_info *info,
434 		       struct vm_area_struct *vma)
435 {
436 	struct clcd_fb *fb = to_clcd(info);
437 	unsigned long len, off = vma->vm_pgoff << PAGE_SHIFT;
438 	int ret = -EINVAL;
439 
440 	len = info->fix.smem_len;
441 
442 	if (off <= len && vma->vm_end - vma->vm_start <= len - off &&
443 	    fb->board->mmap)
444 		ret = fb->board->mmap(fb, vma);
445 
446 	return ret;
447 }
448 
449 static struct fb_ops clcdfb_ops = {
450 	.owner		= THIS_MODULE,
451 	.fb_check_var	= clcdfb_check_var,
452 	.fb_set_par	= clcdfb_set_par,
453 	.fb_setcolreg	= clcdfb_setcolreg,
454 	.fb_blank	= clcdfb_blank,
455 	.fb_fillrect	= cfb_fillrect,
456 	.fb_copyarea	= cfb_copyarea,
457 	.fb_imageblit	= cfb_imageblit,
458 	.fb_mmap	= clcdfb_mmap,
459 };
460 
461 static int clcdfb_register(struct clcd_fb *fb)
462 {
463 	int ret;
464 
465 	/*
466 	 * ARM PL111 always has IENB at 0x1c; it's only PL110
467 	 * which is reversed on some platforms.
468 	 */
469 	if (amba_manf(fb->dev) == 0x41 && amba_part(fb->dev) == 0x111) {
470 		fb->off_ienb = CLCD_PL111_IENB;
471 		fb->off_cntl = CLCD_PL111_CNTL;
472 	} else {
473 		if (of_machine_is_compatible("arm,versatile-ab") ||
474 		    of_machine_is_compatible("arm,versatile-pb")) {
475 			fb->off_ienb = CLCD_PL111_IENB;
476 			fb->off_cntl = CLCD_PL111_CNTL;
477 		} else {
478 			fb->off_ienb = CLCD_PL110_IENB;
479 			fb->off_cntl = CLCD_PL110_CNTL;
480 		}
481 	}
482 
483 	fb->clk = clk_get(&fb->dev->dev, NULL);
484 	if (IS_ERR(fb->clk)) {
485 		ret = PTR_ERR(fb->clk);
486 		goto out;
487 	}
488 
489 	ret = clk_prepare(fb->clk);
490 	if (ret)
491 		goto free_clk;
492 
493 	fb->fb.device		= &fb->dev->dev;
494 
495 	fb->fb.fix.mmio_start	= fb->dev->res.start;
496 	fb->fb.fix.mmio_len	= resource_size(&fb->dev->res);
497 
498 	fb->regs = ioremap(fb->fb.fix.mmio_start, fb->fb.fix.mmio_len);
499 	if (!fb->regs) {
500 		printk(KERN_ERR "CLCD: unable to remap registers\n");
501 		ret = -ENOMEM;
502 		goto clk_unprep;
503 	}
504 
505 	fb->fb.fbops		= &clcdfb_ops;
506 	fb->fb.flags		= FBINFO_FLAG_DEFAULT;
507 	fb->fb.pseudo_palette	= fb->cmap;
508 
509 	strncpy(fb->fb.fix.id, clcd_name, sizeof(fb->fb.fix.id));
510 	fb->fb.fix.type		= FB_TYPE_PACKED_PIXELS;
511 	fb->fb.fix.type_aux	= 0;
512 	fb->fb.fix.xpanstep	= 0;
513 	fb->fb.fix.ypanstep	= 0;
514 	fb->fb.fix.ywrapstep	= 0;
515 	fb->fb.fix.accel	= FB_ACCEL_NONE;
516 
517 	fb->fb.var.xres		= fb->panel->mode.xres;
518 	fb->fb.var.yres		= fb->panel->mode.yres;
519 	fb->fb.var.xres_virtual	= fb->panel->mode.xres;
520 	fb->fb.var.yres_virtual	= fb->panel->mode.yres;
521 	fb->fb.var.bits_per_pixel = fb->panel->bpp;
522 	fb->fb.var.grayscale	= fb->panel->grayscale;
523 	fb->fb.var.pixclock	= fb->panel->mode.pixclock;
524 	fb->fb.var.left_margin	= fb->panel->mode.left_margin;
525 	fb->fb.var.right_margin	= fb->panel->mode.right_margin;
526 	fb->fb.var.upper_margin	= fb->panel->mode.upper_margin;
527 	fb->fb.var.lower_margin	= fb->panel->mode.lower_margin;
528 	fb->fb.var.hsync_len	= fb->panel->mode.hsync_len;
529 	fb->fb.var.vsync_len	= fb->panel->mode.vsync_len;
530 	fb->fb.var.sync		= fb->panel->mode.sync;
531 	fb->fb.var.vmode	= fb->panel->mode.vmode;
532 	fb->fb.var.activate	= FB_ACTIVATE_NOW;
533 	fb->fb.var.nonstd	= 0;
534 	fb->fb.var.height	= fb->panel->height;
535 	fb->fb.var.width	= fb->panel->width;
536 	fb->fb.var.accel_flags	= 0;
537 
538 	fb->fb.monspecs.hfmin	= 0;
539 	fb->fb.monspecs.hfmax   = 100000;
540 	fb->fb.monspecs.vfmin	= 0;
541 	fb->fb.monspecs.vfmax	= 400;
542 	fb->fb.monspecs.dclkmin = 1000000;
543 	fb->fb.monspecs.dclkmax	= 100000000;
544 
545 	/*
546 	 * Make sure that the bitfields are set appropriately.
547 	 */
548 	clcdfb_set_bitfields(fb, &fb->fb.var);
549 
550 	/*
551 	 * Allocate colourmap.
552 	 */
553 	ret = fb_alloc_cmap(&fb->fb.cmap, 256, 0);
554 	if (ret)
555 		goto unmap;
556 
557 	/*
558 	 * Ensure interrupts are disabled.
559 	 */
560 	writel(0, fb->regs + fb->off_ienb);
561 
562 	fb_set_var(&fb->fb, &fb->fb.var);
563 
564 	dev_info(&fb->dev->dev, "%s hardware, %s display\n",
565 	         fb->board->name, fb->panel->mode.name);
566 
567 	ret = register_framebuffer(&fb->fb);
568 	if (ret == 0)
569 		goto out;
570 
571 	printk(KERN_ERR "CLCD: cannot register framebuffer (%d)\n", ret);
572 
573 	fb_dealloc_cmap(&fb->fb.cmap);
574  unmap:
575 	iounmap(fb->regs);
576  clk_unprep:
577 	clk_unprepare(fb->clk);
578  free_clk:
579 	clk_put(fb->clk);
580  out:
581 	return ret;
582 }
583 
584 #ifdef CONFIG_OF
585 static int clcdfb_of_get_dpi_panel_mode(struct device_node *node,
586 		struct clcd_panel *clcd_panel)
587 {
588 	int err;
589 	struct display_timing timing;
590 	struct videomode video;
591 
592 	err = of_get_display_timing(node, "panel-timing", &timing);
593 	if (err)
594 		return err;
595 
596 	videomode_from_timing(&timing, &video);
597 
598 	err = fb_videomode_from_videomode(&video, &clcd_panel->mode);
599 	if (err)
600 		return err;
601 
602 	/* Set up some inversion flags */
603 	if (timing.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
604 		clcd_panel->tim2 |= TIM2_IPC;
605 	else if (!(timing.flags & DISPLAY_FLAGS_PIXDATA_POSEDGE))
606 		/*
607 		 * To preserve backwards compatibility, the IPC (inverted
608 		 * pixel clock) flag needs to be set on any display that
609 		 * doesn't explicitly specify that the pixel clock is
610 		 * active on the negative or positive edge.
611 		 */
612 		clcd_panel->tim2 |= TIM2_IPC;
613 
614 	if (timing.flags & DISPLAY_FLAGS_HSYNC_LOW)
615 		clcd_panel->tim2 |= TIM2_IHS;
616 
617 	if (timing.flags & DISPLAY_FLAGS_VSYNC_LOW)
618 		clcd_panel->tim2 |= TIM2_IVS;
619 
620 	if (timing.flags & DISPLAY_FLAGS_DE_LOW)
621 		clcd_panel->tim2 |= TIM2_IOE;
622 
623 	return 0;
624 }
625 
626 static int clcdfb_snprintf_mode(char *buf, int size, struct fb_videomode *mode)
627 {
628 	return snprintf(buf, size, "%ux%u@%u", mode->xres, mode->yres,
629 			mode->refresh);
630 }
631 
632 static int clcdfb_of_get_backlight(struct device_node *endpoint,
633 				   struct clcd_panel *clcd_panel)
634 {
635 	struct device_node *panel;
636 	struct device_node *backlight;
637 
638 	panel = of_graph_get_remote_port_parent(endpoint);
639 	if (!panel)
640 		return -ENODEV;
641 
642 	/* Look up the optional backlight phandle */
643 	backlight = of_parse_phandle(panel, "backlight", 0);
644 	if (backlight) {
645 		clcd_panel->backlight = of_find_backlight_by_node(backlight);
646 		of_node_put(backlight);
647 
648 		if (!clcd_panel->backlight)
649 			return -EPROBE_DEFER;
650 	}
651 	return 0;
652 }
653 
654 static int clcdfb_of_get_mode(struct device *dev, struct device_node *endpoint,
655 		struct clcd_panel *clcd_panel)
656 {
657 	int err;
658 	struct device_node *panel;
659 	struct fb_videomode *mode;
660 	char *name;
661 	int len;
662 
663 	panel = of_graph_get_remote_port_parent(endpoint);
664 	if (!panel)
665 		return -ENODEV;
666 
667 	/* Only directly connected DPI panels supported for now */
668 	if (of_device_is_compatible(panel, "panel-dpi"))
669 		err = clcdfb_of_get_dpi_panel_mode(panel, clcd_panel);
670 	else
671 		err = -ENOENT;
672 	if (err)
673 		return err;
674 	mode = &clcd_panel->mode;
675 
676 	len = clcdfb_snprintf_mode(NULL, 0, mode);
677 	name = devm_kzalloc(dev, len + 1, GFP_KERNEL);
678 	if (!name)
679 		return -ENOMEM;
680 
681 	clcdfb_snprintf_mode(name, len + 1, mode);
682 	mode->name = name;
683 
684 	return 0;
685 }
686 
687 static int clcdfb_of_init_tft_panel(struct clcd_fb *fb, u32 r0, u32 g0, u32 b0)
688 {
689 	static struct {
690 		unsigned int part;
691 		u32 r0, g0, b0;
692 		u32 caps;
693 	} panels[] = {
694 		{ 0x110, 1,  7, 13, CLCD_CAP_5551 },
695 		{ 0x110, 0,  8, 16, CLCD_CAP_888 },
696 		{ 0x110, 16, 8, 0,  CLCD_CAP_888 },
697 		{ 0x111, 4, 14, 20, CLCD_CAP_444 },
698 		{ 0x111, 3, 11, 19, CLCD_CAP_444 | CLCD_CAP_5551 },
699 		{ 0x111, 3, 10, 19, CLCD_CAP_444 | CLCD_CAP_5551 |
700 				    CLCD_CAP_565 },
701 		{ 0x111, 0,  8, 16, CLCD_CAP_444 | CLCD_CAP_5551 |
702 				    CLCD_CAP_565 | CLCD_CAP_888 },
703 	};
704 	int i;
705 
706 	/* Bypass pixel clock divider */
707 	fb->panel->tim2 |= TIM2_BCD;
708 
709 	/* TFT display, vert. comp. interrupt at the start of the back porch */
710 	fb->panel->cntl |= CNTL_LCDTFT | CNTL_LCDVCOMP(1);
711 
712 	fb->panel->caps = 0;
713 
714 	/* Match the setup with known variants */
715 	for (i = 0; i < ARRAY_SIZE(panels) && !fb->panel->caps; i++) {
716 		if (amba_part(fb->dev) != panels[i].part)
717 			continue;
718 		if (g0 != panels[i].g0)
719 			continue;
720 		if (r0 == panels[i].r0 && b0 == panels[i].b0)
721 			fb->panel->caps = panels[i].caps;
722 	}
723 
724 	/*
725 	 * If we actually physically connected the R lines to B and
726 	 * vice versa
727 	 */
728 	if (r0 != 0 && b0 == 0)
729 		fb->panel->bgr_connection = true;
730 
731 	if (fb->panel->caps && fb->vendor->st_bitmux_control) {
732 		/*
733 		 * Set up the special bits for the Nomadik control register
734 		 * (other platforms tend to do this through an external
735 		 * register).
736 		 */
737 
738 		/* Offset of the highest used color */
739 		int maxoff = max3(r0, g0, b0);
740 		/* Most significant bit out, highest used bit */
741 		int msb = 0;
742 
743 		if (fb->panel->caps & CLCD_CAP_888) {
744 			msb = maxoff + 8 - 1;
745 		} else if (fb->panel->caps & CLCD_CAP_565) {
746 			msb = maxoff + 5 - 1;
747 			fb->panel->cntl |= CNTL_ST_1XBPP_565;
748 		} else if (fb->panel->caps & CLCD_CAP_5551) {
749 			msb = maxoff + 5 - 1;
750 			fb->panel->cntl |= CNTL_ST_1XBPP_5551;
751 		} else if (fb->panel->caps & CLCD_CAP_444) {
752 			msb = maxoff + 4 - 1;
753 			fb->panel->cntl |= CNTL_ST_1XBPP_444;
754 		}
755 
756 		/* Send out as many bits as we need */
757 		if (msb > 17)
758 			fb->panel->cntl |= CNTL_ST_CDWID_24;
759 		else if (msb > 15)
760 			fb->panel->cntl |= CNTL_ST_CDWID_18;
761 		else if (msb > 11)
762 			fb->panel->cntl |= CNTL_ST_CDWID_16;
763 		else
764 			fb->panel->cntl |= CNTL_ST_CDWID_12;
765 	}
766 
767 	return fb->panel->caps ? 0 : -EINVAL;
768 }
769 
770 static int clcdfb_of_init_display(struct clcd_fb *fb)
771 {
772 	struct device_node *endpoint;
773 	int err;
774 	unsigned int bpp;
775 	u32 max_bandwidth;
776 	u32 tft_r0b0g0[3];
777 
778 	fb->panel = devm_kzalloc(&fb->dev->dev, sizeof(*fb->panel), GFP_KERNEL);
779 	if (!fb->panel)
780 		return -ENOMEM;
781 
782 	/*
783 	 * Fetch the panel endpoint.
784 	 */
785 	endpoint = of_graph_get_next_endpoint(fb->dev->dev.of_node, NULL);
786 	if (!endpoint)
787 		return -ENODEV;
788 
789 	if (fb->vendor->init_panel) {
790 		err = fb->vendor->init_panel(fb, endpoint);
791 		if (err)
792 			return err;
793 	}
794 
795 	err = clcdfb_of_get_backlight(endpoint, fb->panel);
796 	if (err)
797 		return err;
798 
799 	err = clcdfb_of_get_mode(&fb->dev->dev, endpoint, fb->panel);
800 	if (err)
801 		return err;
802 
803 	err = of_property_read_u32(fb->dev->dev.of_node, "max-memory-bandwidth",
804 			&max_bandwidth);
805 	if (!err) {
806 		/*
807 		 * max_bandwidth is in bytes per second and pixclock in
808 		 * pico-seconds, so the maximum allowed bits per pixel is
809 		 *   8 * max_bandwidth / (PICOS2KHZ(pixclock) * 1000)
810 		 * Rearrange this calculation to avoid overflow and then ensure
811 		 * result is a valid format.
812 		 */
813 		bpp = max_bandwidth / (1000 / 8)
814 			/ PICOS2KHZ(fb->panel->mode.pixclock);
815 		bpp = rounddown_pow_of_two(bpp);
816 		if (bpp > 32)
817 			bpp = 32;
818 	} else
819 		bpp = 32;
820 	fb->panel->bpp = bpp;
821 
822 #ifdef CONFIG_CPU_BIG_ENDIAN
823 	fb->panel->cntl |= CNTL_BEBO;
824 #endif
825 	fb->panel->width = -1;
826 	fb->panel->height = -1;
827 
828 	if (of_property_read_u32_array(endpoint,
829 			"arm,pl11x,tft-r0g0b0-pads",
830 			tft_r0b0g0, ARRAY_SIZE(tft_r0b0g0)) != 0)
831 		return -ENOENT;
832 
833 	return clcdfb_of_init_tft_panel(fb, tft_r0b0g0[0],
834 					tft_r0b0g0[1],  tft_r0b0g0[2]);
835 }
836 
837 static int clcdfb_of_vram_setup(struct clcd_fb *fb)
838 {
839 	int err;
840 	struct device_node *memory;
841 	u64 size;
842 
843 	err = clcdfb_of_init_display(fb);
844 	if (err)
845 		return err;
846 
847 	memory = of_parse_phandle(fb->dev->dev.of_node, "memory-region", 0);
848 	if (!memory)
849 		return -ENODEV;
850 
851 	fb->fb.screen_base = of_iomap(memory, 0);
852 	if (!fb->fb.screen_base)
853 		return -ENOMEM;
854 
855 	fb->fb.fix.smem_start = of_translate_address(memory,
856 			of_get_address(memory, 0, &size, NULL));
857 	fb->fb.fix.smem_len = size;
858 
859 	return 0;
860 }
861 
862 static int clcdfb_of_vram_mmap(struct clcd_fb *fb, struct vm_area_struct *vma)
863 {
864 	unsigned long off, user_size, kernel_size;
865 
866 
867 	off = vma->vm_pgoff << PAGE_SHIFT;
868 	user_size = vma->vm_end - vma->vm_start;
869 	kernel_size = fb->fb.fix.smem_len;
870 
871 	if (off >= kernel_size || user_size > (kernel_size - off))
872 		return -ENXIO;
873 
874 	return remap_pfn_range(vma, vma->vm_start,
875 			__phys_to_pfn(fb->fb.fix.smem_start) + vma->vm_pgoff,
876 			user_size,
877 			pgprot_writecombine(vma->vm_page_prot));
878 }
879 
880 static void clcdfb_of_vram_remove(struct clcd_fb *fb)
881 {
882 	iounmap(fb->fb.screen_base);
883 }
884 
885 static int clcdfb_of_dma_setup(struct clcd_fb *fb)
886 {
887 	unsigned long framesize;
888 	dma_addr_t dma;
889 	int err;
890 
891 	err = clcdfb_of_init_display(fb);
892 	if (err)
893 		return err;
894 
895 	framesize = fb->panel->mode.xres * fb->panel->mode.yres *
896 			fb->panel->bpp / 8;
897 	fb->fb.screen_base = dma_alloc_coherent(&fb->dev->dev, framesize,
898 			&dma, GFP_KERNEL);
899 	if (!fb->fb.screen_base)
900 		return -ENOMEM;
901 
902 	fb->fb.fix.smem_start = dma;
903 	fb->fb.fix.smem_len = framesize;
904 
905 	return 0;
906 }
907 
908 static int clcdfb_of_dma_mmap(struct clcd_fb *fb, struct vm_area_struct *vma)
909 {
910 	return dma_mmap_wc(&fb->dev->dev, vma, fb->fb.screen_base,
911 			   fb->fb.fix.smem_start, fb->fb.fix.smem_len);
912 }
913 
914 static void clcdfb_of_dma_remove(struct clcd_fb *fb)
915 {
916 	dma_free_coherent(&fb->dev->dev, fb->fb.fix.smem_len,
917 			fb->fb.screen_base, fb->fb.fix.smem_start);
918 }
919 
920 static struct clcd_board *clcdfb_of_get_board(struct amba_device *dev)
921 {
922 	struct clcd_board *board = devm_kzalloc(&dev->dev, sizeof(*board),
923 			GFP_KERNEL);
924 	struct device_node *node = dev->dev.of_node;
925 
926 	if (!board)
927 		return NULL;
928 
929 	board->name = of_node_full_name(node);
930 	board->caps = CLCD_CAP_ALL;
931 	board->check = clcdfb_check;
932 	board->decode = clcdfb_decode;
933 	if (of_find_property(node, "memory-region", NULL)) {
934 		board->setup = clcdfb_of_vram_setup;
935 		board->mmap = clcdfb_of_vram_mmap;
936 		board->remove = clcdfb_of_vram_remove;
937 	} else {
938 		board->setup = clcdfb_of_dma_setup;
939 		board->mmap = clcdfb_of_dma_mmap;
940 		board->remove = clcdfb_of_dma_remove;
941 	}
942 
943 	return board;
944 }
945 #else
946 static struct clcd_board *clcdfb_of_get_board(struct amba_device *dev)
947 {
948 	return NULL;
949 }
950 #endif
951 
952 static int clcdfb_probe(struct amba_device *dev, const struct amba_id *id)
953 {
954 	struct clcd_board *board = dev_get_platdata(&dev->dev);
955 	struct clcd_vendor_data *vendor = id->data;
956 	struct clcd_fb *fb;
957 	int ret;
958 
959 	if (!board)
960 		board = clcdfb_of_get_board(dev);
961 
962 	if (!board)
963 		return -EINVAL;
964 
965 	if (vendor->init_board) {
966 		ret = vendor->init_board(dev, board);
967 		if (ret)
968 			return ret;
969 	}
970 
971 	ret = dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32));
972 	if (ret)
973 		goto out;
974 
975 	ret = amba_request_regions(dev, NULL);
976 	if (ret) {
977 		printk(KERN_ERR "CLCD: unable to reserve regs region\n");
978 		goto out;
979 	}
980 
981 	fb = kzalloc(sizeof(struct clcd_fb), GFP_KERNEL);
982 	if (!fb) {
983 		printk(KERN_INFO "CLCD: could not allocate new clcd_fb struct\n");
984 		ret = -ENOMEM;
985 		goto free_region;
986 	}
987 
988 	fb->dev = dev;
989 	fb->vendor = vendor;
990 	fb->board = board;
991 
992 	dev_info(&fb->dev->dev, "PL%03x designer %02x rev%u at 0x%08llx\n",
993 		amba_part(dev), amba_manf(dev), amba_rev(dev),
994 		(unsigned long long)dev->res.start);
995 
996 	ret = fb->board->setup(fb);
997 	if (ret)
998 		goto free_fb;
999 
1000 	ret = clcdfb_register(fb);
1001 	if (ret == 0) {
1002 		amba_set_drvdata(dev, fb);
1003 		goto out;
1004 	}
1005 
1006 	fb->board->remove(fb);
1007  free_fb:
1008 	kfree(fb);
1009  free_region:
1010 	amba_release_regions(dev);
1011  out:
1012 	return ret;
1013 }
1014 
1015 static int clcdfb_remove(struct amba_device *dev)
1016 {
1017 	struct clcd_fb *fb = amba_get_drvdata(dev);
1018 
1019 	clcdfb_disable(fb);
1020 	unregister_framebuffer(&fb->fb);
1021 	if (fb->fb.cmap.len)
1022 		fb_dealloc_cmap(&fb->fb.cmap);
1023 	iounmap(fb->regs);
1024 	clk_unprepare(fb->clk);
1025 	clk_put(fb->clk);
1026 
1027 	fb->board->remove(fb);
1028 
1029 	kfree(fb);
1030 
1031 	amba_release_regions(dev);
1032 
1033 	return 0;
1034 }
1035 
1036 static struct clcd_vendor_data vendor_arm = {
1037 	/* Sets up the versatile board displays */
1038 	.init_panel = versatile_clcd_init_panel,
1039 };
1040 
1041 static struct clcd_vendor_data vendor_nomadik = {
1042 	.clock_timregs = true,
1043 	.packed_24_bit_pixels = true,
1044 	.st_bitmux_control = true,
1045 	.init_board = nomadik_clcd_init_board,
1046 	.init_panel = nomadik_clcd_init_panel,
1047 };
1048 
1049 static struct amba_id clcdfb_id_table[] = {
1050 	{
1051 		.id	= 0x00041110,
1052 		.mask	= 0x000ffffe,
1053 		.data	= &vendor_arm,
1054 	},
1055 	/* ST Electronics Nomadik variant */
1056 	{
1057 		.id	= 0x00180110,
1058 		.mask	= 0x00fffffe,
1059 		.data	= &vendor_nomadik,
1060 	},
1061 	{ 0, 0 },
1062 };
1063 
1064 MODULE_DEVICE_TABLE(amba, clcdfb_id_table);
1065 
1066 static struct amba_driver clcd_driver = {
1067 	.drv 		= {
1068 		.name	= "clcd-pl11x",
1069 	},
1070 	.probe		= clcdfb_probe,
1071 	.remove		= clcdfb_remove,
1072 	.id_table	= clcdfb_id_table,
1073 };
1074 
1075 static int __init amba_clcdfb_init(void)
1076 {
1077 	if (fb_get_options("ambafb", NULL))
1078 		return -ENODEV;
1079 
1080 	return amba_driver_register(&clcd_driver);
1081 }
1082 
1083 module_init(amba_clcdfb_init);
1084 
1085 static void __exit amba_clcdfb_exit(void)
1086 {
1087 	amba_driver_unregister(&clcd_driver);
1088 }
1089 
1090 module_exit(amba_clcdfb_exit);
1091 
1092 MODULE_DESCRIPTION("ARM PrimeCell PL110 CLCD core driver");
1093 MODULE_LICENSE("GPL");
1094