xref: /openbmc/linux/drivers/video/fbdev/amba-clcd.c (revision e2c75e76)
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/amba/bus.h>
14 #include <linux/amba/clcd.h>
15 #include <linux/backlight.h>
16 #include <linux/clk.h>
17 #include <linux/delay.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/fb.h>
20 #include <linux/init.h>
21 #include <linux/ioport.h>
22 #include <linux/list.h>
23 #include <linux/mm.h>
24 #include <linux/module.h>
25 #include <linux/of_address.h>
26 #include <linux/of_graph.h>
27 #include <linux/slab.h>
28 #include <linux/string.h>
29 #include <video/display_timing.h>
30 #include <video/of_display_timing.h>
31 #include <video/videomode.h>
32 
33 #include "amba-clcd-nomadik.h"
34 #include "amba-clcd-versatile.h"
35 
36 #define to_clcd(info)	container_of(info, struct clcd_fb, fb)
37 
38 /* This is limited to 16 characters when displayed by X startup */
39 static const char *clcd_name = "CLCD FB";
40 
41 /*
42  * Unfortunately, the enable/disable functions may be called either from
43  * process or IRQ context, and we _need_ to delay.  This is _not_ good.
44  */
45 static inline void clcdfb_sleep(unsigned int ms)
46 {
47 	if (in_atomic()) {
48 		mdelay(ms);
49 	} else {
50 		msleep(ms);
51 	}
52 }
53 
54 static inline void clcdfb_set_start(struct clcd_fb *fb)
55 {
56 	unsigned long ustart = fb->fb.fix.smem_start;
57 	unsigned long lstart;
58 
59 	ustart += fb->fb.var.yoffset * fb->fb.fix.line_length;
60 	lstart = ustart + fb->fb.var.yres * fb->fb.fix.line_length / 2;
61 
62 	writel(ustart, fb->regs + CLCD_UBAS);
63 	writel(lstart, fb->regs + CLCD_LBAS);
64 }
65 
66 static void clcdfb_disable(struct clcd_fb *fb)
67 {
68 	u32 val;
69 
70 	if (fb->board->disable)
71 		fb->board->disable(fb);
72 
73 	if (fb->panel->backlight) {
74 		fb->panel->backlight->props.power = FB_BLANK_POWERDOWN;
75 		backlight_update_status(fb->panel->backlight);
76 	}
77 
78 	val = readl(fb->regs + fb->off_cntl);
79 	if (val & CNTL_LCDPWR) {
80 		val &= ~CNTL_LCDPWR;
81 		writel(val, fb->regs + fb->off_cntl);
82 
83 		clcdfb_sleep(20);
84 	}
85 	if (val & CNTL_LCDEN) {
86 		val &= ~CNTL_LCDEN;
87 		writel(val, fb->regs + fb->off_cntl);
88 	}
89 
90 	/*
91 	 * Disable CLCD clock source.
92 	 */
93 	if (fb->clk_enabled) {
94 		fb->clk_enabled = false;
95 		clk_disable(fb->clk);
96 	}
97 }
98 
99 static void clcdfb_enable(struct clcd_fb *fb, u32 cntl)
100 {
101 	/*
102 	 * Enable the CLCD clock source.
103 	 */
104 	if (!fb->clk_enabled) {
105 		fb->clk_enabled = true;
106 		clk_enable(fb->clk);
107 	}
108 
109 	/*
110 	 * Bring up by first enabling..
111 	 */
112 	cntl |= CNTL_LCDEN;
113 	writel(cntl, fb->regs + fb->off_cntl);
114 
115 	clcdfb_sleep(20);
116 
117 	/*
118 	 * and now apply power.
119 	 */
120 	cntl |= CNTL_LCDPWR;
121 	writel(cntl, fb->regs + fb->off_cntl);
122 
123 	/*
124 	 * Turn on backlight
125 	 */
126 	if (fb->panel->backlight) {
127 		fb->panel->backlight->props.power = FB_BLANK_UNBLANK;
128 		backlight_update_status(fb->panel->backlight);
129 	}
130 
131 	/*
132 	 * finally, enable the interface.
133 	 */
134 	if (fb->board->enable)
135 		fb->board->enable(fb);
136 }
137 
138 static int
139 clcdfb_set_bitfields(struct clcd_fb *fb, struct fb_var_screeninfo *var)
140 {
141 	u32 caps;
142 	int ret = 0;
143 
144 	if (fb->panel->caps && fb->board->caps)
145 		caps = fb->panel->caps & fb->board->caps;
146 	else {
147 		/* Old way of specifying what can be used */
148 		caps = fb->panel->cntl & CNTL_BGR ?
149 			CLCD_CAP_BGR : CLCD_CAP_RGB;
150 		/* But mask out 444 modes as they weren't supported */
151 		caps &= ~CLCD_CAP_444;
152 	}
153 
154 	/* Only TFT panels can do RGB888/BGR888 */
155 	if (!(fb->panel->cntl & CNTL_LCDTFT))
156 		caps &= ~CLCD_CAP_888;
157 
158 	memset(&var->transp, 0, sizeof(var->transp));
159 
160 	var->red.msb_right = 0;
161 	var->green.msb_right = 0;
162 	var->blue.msb_right = 0;
163 
164 	switch (var->bits_per_pixel) {
165 	case 1:
166 	case 2:
167 	case 4:
168 	case 8:
169 		/* If we can't do 5551, reject */
170 		caps &= CLCD_CAP_5551;
171 		if (!caps) {
172 			ret = -EINVAL;
173 			break;
174 		}
175 
176 		var->red.length		= var->bits_per_pixel;
177 		var->red.offset		= 0;
178 		var->green.length	= var->bits_per_pixel;
179 		var->green.offset	= 0;
180 		var->blue.length	= var->bits_per_pixel;
181 		var->blue.offset	= 0;
182 		break;
183 
184 	case 16:
185 		/* If we can't do 444, 5551 or 565, reject */
186 		if (!(caps & (CLCD_CAP_444 | CLCD_CAP_5551 | CLCD_CAP_565))) {
187 			ret = -EINVAL;
188 			break;
189 		}
190 
191 		/*
192 		 * Green length can be 4, 5 or 6 depending whether
193 		 * we're operating in 444, 5551 or 565 mode.
194 		 */
195 		if (var->green.length == 4 && caps & CLCD_CAP_444)
196 			caps &= CLCD_CAP_444;
197 		if (var->green.length == 5 && caps & CLCD_CAP_5551)
198 			caps &= CLCD_CAP_5551;
199 		else if (var->green.length == 6 && caps & CLCD_CAP_565)
200 			caps &= CLCD_CAP_565;
201 		else {
202 			/*
203 			 * PL110 officially only supports RGB555,
204 			 * but may be wired up to allow RGB565.
205 			 */
206 			if (caps & CLCD_CAP_565) {
207 				var->green.length = 6;
208 				caps &= CLCD_CAP_565;
209 			} else if (caps & CLCD_CAP_5551) {
210 				var->green.length = 5;
211 				caps &= CLCD_CAP_5551;
212 			} else {
213 				var->green.length = 4;
214 				caps &= CLCD_CAP_444;
215 			}
216 		}
217 
218 		if (var->green.length >= 5) {
219 			var->red.length = 5;
220 			var->blue.length = 5;
221 		} else {
222 			var->red.length = 4;
223 			var->blue.length = 4;
224 		}
225 		break;
226 	case 24:
227 		if (fb->vendor->packed_24_bit_pixels) {
228 			var->red.length = 8;
229 			var->green.length = 8;
230 			var->blue.length = 8;
231 		} else {
232 			ret = -EINVAL;
233 		}
234 		break;
235 	case 32:
236 		/* If we can't do 888, reject */
237 		caps &= CLCD_CAP_888;
238 		if (!caps) {
239 			ret = -EINVAL;
240 			break;
241 		}
242 
243 		var->red.length = 8;
244 		var->green.length = 8;
245 		var->blue.length = 8;
246 		break;
247 	default:
248 		ret = -EINVAL;
249 		break;
250 	}
251 
252 	/*
253 	 * >= 16bpp displays have separate colour component bitfields
254 	 * encoded in the pixel data.  Calculate their position from
255 	 * the bitfield length defined above.
256 	 */
257 	if (ret == 0 && var->bits_per_pixel >= 16) {
258 		bool bgr, rgb;
259 
260 		bgr = caps & CLCD_CAP_BGR && var->blue.offset == 0;
261 		rgb = caps & CLCD_CAP_RGB && var->red.offset == 0;
262 
263 		if (!bgr && !rgb)
264 			/*
265 			 * The requested format was not possible, try just
266 			 * our capabilities.  One of BGR or RGB must be
267 			 * supported.
268 			 */
269 			bgr = caps & CLCD_CAP_BGR;
270 
271 		if (bgr) {
272 			var->blue.offset = 0;
273 			var->green.offset = var->blue.offset + var->blue.length;
274 			var->red.offset = var->green.offset + var->green.length;
275 		} else {
276 			var->red.offset = 0;
277 			var->green.offset = var->red.offset + var->red.length;
278 			var->blue.offset = var->green.offset + var->green.length;
279 		}
280 	}
281 
282 	return ret;
283 }
284 
285 static int clcdfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
286 {
287 	struct clcd_fb *fb = to_clcd(info);
288 	int ret = -EINVAL;
289 
290 	if (fb->board->check)
291 		ret = fb->board->check(fb, var);
292 
293 	if (ret == 0 &&
294 	    var->xres_virtual * var->bits_per_pixel / 8 *
295 	    var->yres_virtual > fb->fb.fix.smem_len)
296 		ret = -EINVAL;
297 
298 	if (ret == 0)
299 		ret = clcdfb_set_bitfields(fb, var);
300 
301 	return ret;
302 }
303 
304 static int clcdfb_set_par(struct fb_info *info)
305 {
306 	struct clcd_fb *fb = to_clcd(info);
307 	struct clcd_regs regs;
308 
309 	fb->fb.fix.line_length = fb->fb.var.xres_virtual *
310 				 fb->fb.var.bits_per_pixel / 8;
311 
312 	if (fb->fb.var.bits_per_pixel <= 8)
313 		fb->fb.fix.visual = FB_VISUAL_PSEUDOCOLOR;
314 	else
315 		fb->fb.fix.visual = FB_VISUAL_TRUECOLOR;
316 
317 	fb->board->decode(fb, &regs);
318 
319 	clcdfb_disable(fb);
320 
321 	/* Some variants must be clocked here */
322 	if (fb->vendor->clock_timregs && !fb->clk_enabled) {
323 		fb->clk_enabled = true;
324 		clk_enable(fb->clk);
325 	}
326 
327 	writel(regs.tim0, fb->regs + CLCD_TIM0);
328 	writel(regs.tim1, fb->regs + CLCD_TIM1);
329 	writel(regs.tim2, fb->regs + CLCD_TIM2);
330 	writel(regs.tim3, fb->regs + CLCD_TIM3);
331 
332 	clcdfb_set_start(fb);
333 
334 	clk_set_rate(fb->clk, (1000000000 / regs.pixclock) * 1000);
335 
336 	fb->clcd_cntl = regs.cntl;
337 
338 	clcdfb_enable(fb, regs.cntl);
339 
340 #ifdef DEBUG
341 	printk(KERN_INFO
342 	       "CLCD: Registers set to\n"
343 	       "  %08x %08x %08x %08x\n"
344 	       "  %08x %08x %08x %08x\n",
345 		readl(fb->regs + CLCD_TIM0), readl(fb->regs + CLCD_TIM1),
346 		readl(fb->regs + CLCD_TIM2), readl(fb->regs + CLCD_TIM3),
347 		readl(fb->regs + CLCD_UBAS), readl(fb->regs + CLCD_LBAS),
348 		readl(fb->regs + fb->off_ienb), readl(fb->regs + fb->off_cntl));
349 #endif
350 
351 	return 0;
352 }
353 
354 static inline u32 convert_bitfield(int val, struct fb_bitfield *bf)
355 {
356 	unsigned int mask = (1 << bf->length) - 1;
357 
358 	return (val >> (16 - bf->length) & mask) << bf->offset;
359 }
360 
361 /*
362  *  Set a single color register. The values supplied have a 16 bit
363  *  magnitude.  Return != 0 for invalid regno.
364  */
365 static int
366 clcdfb_setcolreg(unsigned int regno, unsigned int red, unsigned int green,
367 		 unsigned int blue, unsigned int transp, struct fb_info *info)
368 {
369 	struct clcd_fb *fb = to_clcd(info);
370 
371 	if (regno < 16)
372 		fb->cmap[regno] = convert_bitfield(transp, &fb->fb.var.transp) |
373 				  convert_bitfield(blue, &fb->fb.var.blue) |
374 				  convert_bitfield(green, &fb->fb.var.green) |
375 				  convert_bitfield(red, &fb->fb.var.red);
376 
377 	if (fb->fb.fix.visual == FB_VISUAL_PSEUDOCOLOR && regno < 256) {
378 		int hw_reg = CLCD_PALETTE + ((regno * 2) & ~3);
379 		u32 val, mask, newval;
380 
381 		newval  = (red >> 11)  & 0x001f;
382 		newval |= (green >> 6) & 0x03e0;
383 		newval |= (blue >> 1)  & 0x7c00;
384 
385 		/*
386 		 * 3.2.11: if we're configured for big endian
387 		 * byte order, the palette entries are swapped.
388 		 */
389 		if (fb->clcd_cntl & CNTL_BEBO)
390 			regno ^= 1;
391 
392 		if (regno & 1) {
393 			newval <<= 16;
394 			mask = 0x0000ffff;
395 		} else {
396 			mask = 0xffff0000;
397 		}
398 
399 		val = readl(fb->regs + hw_reg) & mask;
400 		writel(val | newval, fb->regs + hw_reg);
401 	}
402 
403 	return regno > 255;
404 }
405 
406 /*
407  *  Blank the screen if blank_mode != 0, else unblank. If blank == NULL
408  *  then the caller blanks by setting the CLUT (Color Look Up Table) to all
409  *  black. Return 0 if blanking succeeded, != 0 if un-/blanking failed due
410  *  to e.g. a video mode which doesn't support it. Implements VESA suspend
411  *  and powerdown modes on hardware that supports disabling hsync/vsync:
412  *    blank_mode == 2: suspend vsync
413  *    blank_mode == 3: suspend hsync
414  *    blank_mode == 4: powerdown
415  */
416 static int clcdfb_blank(int blank_mode, struct fb_info *info)
417 {
418 	struct clcd_fb *fb = to_clcd(info);
419 
420 	if (blank_mode != 0) {
421 		clcdfb_disable(fb);
422 	} else {
423 		clcdfb_enable(fb, fb->clcd_cntl);
424 	}
425 	return 0;
426 }
427 
428 static int clcdfb_mmap(struct fb_info *info,
429 		       struct vm_area_struct *vma)
430 {
431 	struct clcd_fb *fb = to_clcd(info);
432 	unsigned long len, off = vma->vm_pgoff << PAGE_SHIFT;
433 	int ret = -EINVAL;
434 
435 	len = info->fix.smem_len;
436 
437 	if (off <= len && vma->vm_end - vma->vm_start <= len - off &&
438 	    fb->board->mmap)
439 		ret = fb->board->mmap(fb, vma);
440 
441 	return ret;
442 }
443 
444 static struct fb_ops clcdfb_ops = {
445 	.owner		= THIS_MODULE,
446 	.fb_check_var	= clcdfb_check_var,
447 	.fb_set_par	= clcdfb_set_par,
448 	.fb_setcolreg	= clcdfb_setcolreg,
449 	.fb_blank	= clcdfb_blank,
450 	.fb_fillrect	= cfb_fillrect,
451 	.fb_copyarea	= cfb_copyarea,
452 	.fb_imageblit	= cfb_imageblit,
453 	.fb_mmap	= clcdfb_mmap,
454 };
455 
456 static int clcdfb_register(struct clcd_fb *fb)
457 {
458 	int ret;
459 
460 	/*
461 	 * ARM PL111 always has IENB at 0x1c; it's only PL110
462 	 * which is reversed on some platforms.
463 	 */
464 	if (amba_manf(fb->dev) == 0x41 && amba_part(fb->dev) == 0x111) {
465 		fb->off_ienb = CLCD_PL111_IENB;
466 		fb->off_cntl = CLCD_PL111_CNTL;
467 	} else {
468 		if (of_machine_is_compatible("arm,versatile-ab") ||
469 		    of_machine_is_compatible("arm,versatile-pb")) {
470 			fb->off_ienb = CLCD_PL111_IENB;
471 			fb->off_cntl = CLCD_PL111_CNTL;
472 		} else {
473 			fb->off_ienb = CLCD_PL110_IENB;
474 			fb->off_cntl = CLCD_PL110_CNTL;
475 		}
476 	}
477 
478 	fb->clk = clk_get(&fb->dev->dev, NULL);
479 	if (IS_ERR(fb->clk)) {
480 		ret = PTR_ERR(fb->clk);
481 		goto out;
482 	}
483 
484 	ret = clk_prepare(fb->clk);
485 	if (ret)
486 		goto free_clk;
487 
488 	fb->fb.device		= &fb->dev->dev;
489 
490 	fb->fb.fix.mmio_start	= fb->dev->res.start;
491 	fb->fb.fix.mmio_len	= resource_size(&fb->dev->res);
492 
493 	fb->regs = ioremap(fb->fb.fix.mmio_start, fb->fb.fix.mmio_len);
494 	if (!fb->regs) {
495 		printk(KERN_ERR "CLCD: unable to remap registers\n");
496 		ret = -ENOMEM;
497 		goto clk_unprep;
498 	}
499 
500 	fb->fb.fbops		= &clcdfb_ops;
501 	fb->fb.flags		= FBINFO_FLAG_DEFAULT;
502 	fb->fb.pseudo_palette	= fb->cmap;
503 
504 	strncpy(fb->fb.fix.id, clcd_name, sizeof(fb->fb.fix.id));
505 	fb->fb.fix.type		= FB_TYPE_PACKED_PIXELS;
506 	fb->fb.fix.type_aux	= 0;
507 	fb->fb.fix.xpanstep	= 0;
508 	fb->fb.fix.ypanstep	= 0;
509 	fb->fb.fix.ywrapstep	= 0;
510 	fb->fb.fix.accel	= FB_ACCEL_NONE;
511 
512 	fb->fb.var.xres		= fb->panel->mode.xres;
513 	fb->fb.var.yres		= fb->panel->mode.yres;
514 	fb->fb.var.xres_virtual	= fb->panel->mode.xres;
515 	fb->fb.var.yres_virtual	= fb->panel->mode.yres;
516 	fb->fb.var.bits_per_pixel = fb->panel->bpp;
517 	fb->fb.var.grayscale	= fb->panel->grayscale;
518 	fb->fb.var.pixclock	= fb->panel->mode.pixclock;
519 	fb->fb.var.left_margin	= fb->panel->mode.left_margin;
520 	fb->fb.var.right_margin	= fb->panel->mode.right_margin;
521 	fb->fb.var.upper_margin	= fb->panel->mode.upper_margin;
522 	fb->fb.var.lower_margin	= fb->panel->mode.lower_margin;
523 	fb->fb.var.hsync_len	= fb->panel->mode.hsync_len;
524 	fb->fb.var.vsync_len	= fb->panel->mode.vsync_len;
525 	fb->fb.var.sync		= fb->panel->mode.sync;
526 	fb->fb.var.vmode	= fb->panel->mode.vmode;
527 	fb->fb.var.activate	= FB_ACTIVATE_NOW;
528 	fb->fb.var.nonstd	= 0;
529 	fb->fb.var.height	= fb->panel->height;
530 	fb->fb.var.width	= fb->panel->width;
531 	fb->fb.var.accel_flags	= 0;
532 
533 	fb->fb.monspecs.hfmin	= 0;
534 	fb->fb.monspecs.hfmax   = 100000;
535 	fb->fb.monspecs.vfmin	= 0;
536 	fb->fb.monspecs.vfmax	= 400;
537 	fb->fb.monspecs.dclkmin = 1000000;
538 	fb->fb.monspecs.dclkmax	= 100000000;
539 
540 	/*
541 	 * Make sure that the bitfields are set appropriately.
542 	 */
543 	clcdfb_set_bitfields(fb, &fb->fb.var);
544 
545 	/*
546 	 * Allocate colourmap.
547 	 */
548 	ret = fb_alloc_cmap(&fb->fb.cmap, 256, 0);
549 	if (ret)
550 		goto unmap;
551 
552 	/*
553 	 * Ensure interrupts are disabled.
554 	 */
555 	writel(0, fb->regs + fb->off_ienb);
556 
557 	fb_set_var(&fb->fb, &fb->fb.var);
558 
559 	dev_info(&fb->dev->dev, "%s hardware, %s display\n",
560 	         fb->board->name, fb->panel->mode.name);
561 
562 	ret = register_framebuffer(&fb->fb);
563 	if (ret == 0)
564 		goto out;
565 
566 	printk(KERN_ERR "CLCD: cannot register framebuffer (%d)\n", ret);
567 
568 	fb_dealloc_cmap(&fb->fb.cmap);
569  unmap:
570 	iounmap(fb->regs);
571  clk_unprep:
572 	clk_unprepare(fb->clk);
573  free_clk:
574 	clk_put(fb->clk);
575  out:
576 	return ret;
577 }
578 
579 #ifdef CONFIG_OF
580 static int clcdfb_of_get_dpi_panel_mode(struct device_node *node,
581 		struct clcd_panel *clcd_panel)
582 {
583 	int err;
584 	struct display_timing timing;
585 	struct videomode video;
586 
587 	err = of_get_display_timing(node, "panel-timing", &timing);
588 	if (err)
589 		return err;
590 
591 	videomode_from_timing(&timing, &video);
592 
593 	err = fb_videomode_from_videomode(&video, &clcd_panel->mode);
594 	if (err)
595 		return err;
596 
597 	/* Set up some inversion flags */
598 	if (timing.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
599 		clcd_panel->tim2 |= TIM2_IPC;
600 	else if (!(timing.flags & DISPLAY_FLAGS_PIXDATA_POSEDGE))
601 		/*
602 		 * To preserve backwards compatibility, the IPC (inverted
603 		 * pixel clock) flag needs to be set on any display that
604 		 * doesn't explicitly specify that the pixel clock is
605 		 * active on the negative or positive edge.
606 		 */
607 		clcd_panel->tim2 |= TIM2_IPC;
608 
609 	if (timing.flags & DISPLAY_FLAGS_HSYNC_LOW)
610 		clcd_panel->tim2 |= TIM2_IHS;
611 
612 	if (timing.flags & DISPLAY_FLAGS_VSYNC_LOW)
613 		clcd_panel->tim2 |= TIM2_IVS;
614 
615 	if (timing.flags & DISPLAY_FLAGS_DE_LOW)
616 		clcd_panel->tim2 |= TIM2_IOE;
617 
618 	return 0;
619 }
620 
621 static int clcdfb_snprintf_mode(char *buf, int size, struct fb_videomode *mode)
622 {
623 	return snprintf(buf, size, "%ux%u@%u", mode->xres, mode->yres,
624 			mode->refresh);
625 }
626 
627 static int clcdfb_of_get_backlight(struct device_node *panel,
628 				   struct clcd_panel *clcd_panel)
629 {
630 	struct device_node *backlight;
631 
632 	/* Look up the optional backlight phandle */
633 	backlight = of_parse_phandle(panel, "backlight", 0);
634 	if (backlight) {
635 		clcd_panel->backlight = of_find_backlight_by_node(backlight);
636 		of_node_put(backlight);
637 
638 		if (!clcd_panel->backlight)
639 			return -EPROBE_DEFER;
640 	}
641 	return 0;
642 }
643 
644 static int clcdfb_of_get_mode(struct device *dev, struct device_node *panel,
645 			      struct clcd_panel *clcd_panel)
646 {
647 	int err;
648 	struct fb_videomode *mode;
649 	char *name;
650 	int len;
651 
652 	/* Only directly connected DPI panels supported for now */
653 	if (of_device_is_compatible(panel, "panel-dpi"))
654 		err = clcdfb_of_get_dpi_panel_mode(panel, clcd_panel);
655 	else
656 		err = -ENOENT;
657 	if (err)
658 		return err;
659 	mode = &clcd_panel->mode;
660 
661 	len = clcdfb_snprintf_mode(NULL, 0, mode);
662 	name = devm_kzalloc(dev, len + 1, GFP_KERNEL);
663 	if (!name)
664 		return -ENOMEM;
665 
666 	clcdfb_snprintf_mode(name, len + 1, mode);
667 	mode->name = name;
668 
669 	return 0;
670 }
671 
672 static int clcdfb_of_init_tft_panel(struct clcd_fb *fb, u32 r0, u32 g0, u32 b0)
673 {
674 	static struct {
675 		unsigned int part;
676 		u32 r0, g0, b0;
677 		u32 caps;
678 	} panels[] = {
679 		{ 0x110, 1,  7, 13, CLCD_CAP_5551 },
680 		{ 0x110, 0,  8, 16, CLCD_CAP_888 },
681 		{ 0x110, 16, 8, 0,  CLCD_CAP_888 },
682 		{ 0x111, 4, 14, 20, CLCD_CAP_444 },
683 		{ 0x111, 3, 11, 19, CLCD_CAP_444 | CLCD_CAP_5551 },
684 		{ 0x111, 3, 10, 19, CLCD_CAP_444 | CLCD_CAP_5551 |
685 				    CLCD_CAP_565 },
686 		{ 0x111, 0,  8, 16, CLCD_CAP_444 | CLCD_CAP_5551 |
687 				    CLCD_CAP_565 | CLCD_CAP_888 },
688 	};
689 	int i;
690 
691 	/* Bypass pixel clock divider */
692 	fb->panel->tim2 |= TIM2_BCD;
693 
694 	/* TFT display, vert. comp. interrupt at the start of the back porch */
695 	fb->panel->cntl |= CNTL_LCDTFT | CNTL_LCDVCOMP(1);
696 
697 	fb->panel->caps = 0;
698 
699 	/* Match the setup with known variants */
700 	for (i = 0; i < ARRAY_SIZE(panels) && !fb->panel->caps; i++) {
701 		if (amba_part(fb->dev) != panels[i].part)
702 			continue;
703 		if (g0 != panels[i].g0)
704 			continue;
705 		if (r0 == panels[i].r0 && b0 == panels[i].b0)
706 			fb->panel->caps = panels[i].caps;
707 	}
708 
709 	/*
710 	 * If we actually physically connected the R lines to B and
711 	 * vice versa
712 	 */
713 	if (r0 != 0 && b0 == 0)
714 		fb->panel->bgr_connection = true;
715 
716 	if (fb->panel->caps && fb->vendor->st_bitmux_control) {
717 		/*
718 		 * Set up the special bits for the Nomadik control register
719 		 * (other platforms tend to do this through an external
720 		 * register).
721 		 */
722 
723 		/* Offset of the highest used color */
724 		int maxoff = max3(r0, g0, b0);
725 		/* Most significant bit out, highest used bit */
726 		int msb = 0;
727 
728 		if (fb->panel->caps & CLCD_CAP_888) {
729 			msb = maxoff + 8 - 1;
730 		} else if (fb->panel->caps & CLCD_CAP_565) {
731 			msb = maxoff + 5 - 1;
732 			fb->panel->cntl |= CNTL_ST_1XBPP_565;
733 		} else if (fb->panel->caps & CLCD_CAP_5551) {
734 			msb = maxoff + 5 - 1;
735 			fb->panel->cntl |= CNTL_ST_1XBPP_5551;
736 		} else if (fb->panel->caps & CLCD_CAP_444) {
737 			msb = maxoff + 4 - 1;
738 			fb->panel->cntl |= CNTL_ST_1XBPP_444;
739 		}
740 
741 		/* Send out as many bits as we need */
742 		if (msb > 17)
743 			fb->panel->cntl |= CNTL_ST_CDWID_24;
744 		else if (msb > 15)
745 			fb->panel->cntl |= CNTL_ST_CDWID_18;
746 		else if (msb > 11)
747 			fb->panel->cntl |= CNTL_ST_CDWID_16;
748 		else
749 			fb->panel->cntl |= CNTL_ST_CDWID_12;
750 	}
751 
752 	return fb->panel->caps ? 0 : -EINVAL;
753 }
754 
755 static int clcdfb_of_init_display(struct clcd_fb *fb)
756 {
757 	struct device_node *endpoint, *panel;
758 	int err;
759 	unsigned int bpp;
760 	u32 max_bandwidth;
761 	u32 tft_r0b0g0[3];
762 
763 	fb->panel = devm_kzalloc(&fb->dev->dev, sizeof(*fb->panel), GFP_KERNEL);
764 	if (!fb->panel)
765 		return -ENOMEM;
766 
767 	/*
768 	 * Fetch the panel endpoint.
769 	 */
770 	endpoint = of_graph_get_next_endpoint(fb->dev->dev.of_node, NULL);
771 	if (!endpoint)
772 		return -ENODEV;
773 
774 	panel = of_graph_get_remote_port_parent(endpoint);
775 	if (!panel)
776 		return -ENODEV;
777 
778 	if (fb->vendor->init_panel) {
779 		err = fb->vendor->init_panel(fb, panel);
780 		if (err)
781 			return err;
782 	}
783 
784 	err = clcdfb_of_get_backlight(panel, fb->panel);
785 	if (err)
786 		return err;
787 
788 	err = clcdfb_of_get_mode(&fb->dev->dev, panel, fb->panel);
789 	if (err)
790 		return err;
791 
792 	err = of_property_read_u32(fb->dev->dev.of_node, "max-memory-bandwidth",
793 			&max_bandwidth);
794 	if (!err) {
795 		/*
796 		 * max_bandwidth is in bytes per second and pixclock in
797 		 * pico-seconds, so the maximum allowed bits per pixel is
798 		 *   8 * max_bandwidth / (PICOS2KHZ(pixclock) * 1000)
799 		 * Rearrange this calculation to avoid overflow and then ensure
800 		 * result is a valid format.
801 		 */
802 		bpp = max_bandwidth / (1000 / 8)
803 			/ PICOS2KHZ(fb->panel->mode.pixclock);
804 		bpp = rounddown_pow_of_two(bpp);
805 		if (bpp > 32)
806 			bpp = 32;
807 	} else
808 		bpp = 32;
809 	fb->panel->bpp = bpp;
810 
811 #ifdef CONFIG_CPU_BIG_ENDIAN
812 	fb->panel->cntl |= CNTL_BEBO;
813 #endif
814 	fb->panel->width = -1;
815 	fb->panel->height = -1;
816 
817 	if (of_property_read_u32_array(endpoint,
818 			"arm,pl11x,tft-r0g0b0-pads",
819 			tft_r0b0g0, ARRAY_SIZE(tft_r0b0g0)) != 0)
820 		return -ENOENT;
821 
822 	return clcdfb_of_init_tft_panel(fb, tft_r0b0g0[0],
823 					tft_r0b0g0[1],  tft_r0b0g0[2]);
824 }
825 
826 static int clcdfb_of_vram_setup(struct clcd_fb *fb)
827 {
828 	int err;
829 	struct device_node *memory;
830 	u64 size;
831 
832 	err = clcdfb_of_init_display(fb);
833 	if (err)
834 		return err;
835 
836 	memory = of_parse_phandle(fb->dev->dev.of_node, "memory-region", 0);
837 	if (!memory)
838 		return -ENODEV;
839 
840 	fb->fb.screen_base = of_iomap(memory, 0);
841 	if (!fb->fb.screen_base)
842 		return -ENOMEM;
843 
844 	fb->fb.fix.smem_start = of_translate_address(memory,
845 			of_get_address(memory, 0, &size, NULL));
846 	fb->fb.fix.smem_len = size;
847 
848 	return 0;
849 }
850 
851 static int clcdfb_of_vram_mmap(struct clcd_fb *fb, struct vm_area_struct *vma)
852 {
853 	unsigned long off, user_size, kernel_size;
854 
855 
856 	off = vma->vm_pgoff << PAGE_SHIFT;
857 	user_size = vma->vm_end - vma->vm_start;
858 	kernel_size = fb->fb.fix.smem_len;
859 
860 	if (off >= kernel_size || user_size > (kernel_size - off))
861 		return -ENXIO;
862 
863 	return remap_pfn_range(vma, vma->vm_start,
864 			__phys_to_pfn(fb->fb.fix.smem_start) + vma->vm_pgoff,
865 			user_size,
866 			pgprot_writecombine(vma->vm_page_prot));
867 }
868 
869 static void clcdfb_of_vram_remove(struct clcd_fb *fb)
870 {
871 	iounmap(fb->fb.screen_base);
872 }
873 
874 static int clcdfb_of_dma_setup(struct clcd_fb *fb)
875 {
876 	unsigned long framesize;
877 	dma_addr_t dma;
878 	int err;
879 
880 	err = clcdfb_of_init_display(fb);
881 	if (err)
882 		return err;
883 
884 	framesize = PAGE_ALIGN(fb->panel->mode.xres * fb->panel->mode.yres *
885 			fb->panel->bpp / 8);
886 	fb->fb.screen_base = dma_alloc_coherent(&fb->dev->dev, framesize,
887 			&dma, GFP_KERNEL);
888 	if (!fb->fb.screen_base)
889 		return -ENOMEM;
890 
891 	fb->fb.fix.smem_start = dma;
892 	fb->fb.fix.smem_len = framesize;
893 
894 	return 0;
895 }
896 
897 static int clcdfb_of_dma_mmap(struct clcd_fb *fb, struct vm_area_struct *vma)
898 {
899 	return dma_mmap_wc(&fb->dev->dev, vma, fb->fb.screen_base,
900 			   fb->fb.fix.smem_start, fb->fb.fix.smem_len);
901 }
902 
903 static void clcdfb_of_dma_remove(struct clcd_fb *fb)
904 {
905 	dma_free_coherent(&fb->dev->dev, fb->fb.fix.smem_len,
906 			fb->fb.screen_base, fb->fb.fix.smem_start);
907 }
908 
909 static struct clcd_board *clcdfb_of_get_board(struct amba_device *dev)
910 {
911 	struct clcd_board *board = devm_kzalloc(&dev->dev, sizeof(*board),
912 			GFP_KERNEL);
913 	struct device_node *node = dev->dev.of_node;
914 
915 	if (!board)
916 		return NULL;
917 
918 	board->name = of_node_full_name(node);
919 	board->caps = CLCD_CAP_ALL;
920 	board->check = clcdfb_check;
921 	board->decode = clcdfb_decode;
922 	if (of_find_property(node, "memory-region", NULL)) {
923 		board->setup = clcdfb_of_vram_setup;
924 		board->mmap = clcdfb_of_vram_mmap;
925 		board->remove = clcdfb_of_vram_remove;
926 	} else {
927 		board->setup = clcdfb_of_dma_setup;
928 		board->mmap = clcdfb_of_dma_mmap;
929 		board->remove = clcdfb_of_dma_remove;
930 	}
931 
932 	return board;
933 }
934 #else
935 static struct clcd_board *clcdfb_of_get_board(struct amba_device *dev)
936 {
937 	return NULL;
938 }
939 #endif
940 
941 static int clcdfb_probe(struct amba_device *dev, const struct amba_id *id)
942 {
943 	struct clcd_board *board = dev_get_platdata(&dev->dev);
944 	struct clcd_vendor_data *vendor = id->data;
945 	struct clcd_fb *fb;
946 	int ret;
947 
948 	if (!board)
949 		board = clcdfb_of_get_board(dev);
950 
951 	if (!board)
952 		return -EINVAL;
953 
954 	if (vendor->init_board) {
955 		ret = vendor->init_board(dev, board);
956 		if (ret)
957 			return ret;
958 	}
959 
960 	ret = dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32));
961 	if (ret)
962 		goto out;
963 
964 	ret = amba_request_regions(dev, NULL);
965 	if (ret) {
966 		printk(KERN_ERR "CLCD: unable to reserve regs region\n");
967 		goto out;
968 	}
969 
970 	fb = kzalloc(sizeof(struct clcd_fb), GFP_KERNEL);
971 	if (!fb) {
972 		printk(KERN_INFO "CLCD: could not allocate new clcd_fb struct\n");
973 		ret = -ENOMEM;
974 		goto free_region;
975 	}
976 
977 	fb->dev = dev;
978 	fb->vendor = vendor;
979 	fb->board = board;
980 
981 	dev_info(&fb->dev->dev, "PL%03x designer %02x rev%u at 0x%08llx\n",
982 		amba_part(dev), amba_manf(dev), amba_rev(dev),
983 		(unsigned long long)dev->res.start);
984 
985 	ret = fb->board->setup(fb);
986 	if (ret)
987 		goto free_fb;
988 
989 	ret = clcdfb_register(fb);
990 	if (ret == 0) {
991 		amba_set_drvdata(dev, fb);
992 		goto out;
993 	}
994 
995 	fb->board->remove(fb);
996  free_fb:
997 	kfree(fb);
998  free_region:
999 	amba_release_regions(dev);
1000  out:
1001 	return ret;
1002 }
1003 
1004 static int clcdfb_remove(struct amba_device *dev)
1005 {
1006 	struct clcd_fb *fb = amba_get_drvdata(dev);
1007 
1008 	clcdfb_disable(fb);
1009 	unregister_framebuffer(&fb->fb);
1010 	if (fb->fb.cmap.len)
1011 		fb_dealloc_cmap(&fb->fb.cmap);
1012 	iounmap(fb->regs);
1013 	clk_unprepare(fb->clk);
1014 	clk_put(fb->clk);
1015 
1016 	fb->board->remove(fb);
1017 
1018 	kfree(fb);
1019 
1020 	amba_release_regions(dev);
1021 
1022 	return 0;
1023 }
1024 
1025 static struct clcd_vendor_data vendor_arm = {
1026 	/* Sets up the versatile board displays */
1027 	.init_panel = versatile_clcd_init_panel,
1028 };
1029 
1030 static struct clcd_vendor_data vendor_nomadik = {
1031 	.clock_timregs = true,
1032 	.packed_24_bit_pixels = true,
1033 	.st_bitmux_control = true,
1034 	.init_board = nomadik_clcd_init_board,
1035 	.init_panel = nomadik_clcd_init_panel,
1036 };
1037 
1038 static const struct amba_id clcdfb_id_table[] = {
1039 	{
1040 		.id	= 0x00041110,
1041 		.mask	= 0x000ffffe,
1042 		.data	= &vendor_arm,
1043 	},
1044 	/* ST Electronics Nomadik variant */
1045 	{
1046 		.id	= 0x00180110,
1047 		.mask	= 0x00fffffe,
1048 		.data	= &vendor_nomadik,
1049 	},
1050 	{ 0, 0 },
1051 };
1052 
1053 MODULE_DEVICE_TABLE(amba, clcdfb_id_table);
1054 
1055 static struct amba_driver clcd_driver = {
1056 	.drv 		= {
1057 		.name	= "clcd-pl11x",
1058 	},
1059 	.probe		= clcdfb_probe,
1060 	.remove		= clcdfb_remove,
1061 	.id_table	= clcdfb_id_table,
1062 };
1063 
1064 static int __init amba_clcdfb_init(void)
1065 {
1066 	if (fb_get_options("ambafb", NULL))
1067 		return -ENODEV;
1068 
1069 	return amba_driver_register(&clcd_driver);
1070 }
1071 
1072 module_init(amba_clcdfb_init);
1073 
1074 static void __exit amba_clcdfb_exit(void)
1075 {
1076 	amba_driver_unregister(&clcd_driver);
1077 }
1078 
1079 module_exit(amba_clcdfb_exit);
1080 
1081 MODULE_DESCRIPTION("ARM PrimeCell PL110 CLCD core driver");
1082 MODULE_LICENSE("GPL");
1083