xref: /openbmc/linux/drivers/video/fbdev/ep93xx-fb.c (revision 8e774e02)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * linux/drivers/video/ep93xx-fb.c
4  *
5  * Framebuffer support for the EP93xx series.
6  *
7  * Copyright (C) 2007 Bluewater Systems Ltd
8  * Author: Ryan Mallon
9  *
10  * Copyright (c) 2009 H Hartley Sweeten <hsweeten@visionengravers.com>
11  *
12  * Based on the Cirrus Logic ep93xxfb driver, and various other ep93xxfb
13  * drivers.
14  */
15 
16 #include <linux/platform_device.h>
17 #include <linux/module.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/slab.h>
20 #include <linux/clk.h>
21 #include <linux/fb.h>
22 #include <linux/io.h>
23 
24 #include <linux/platform_data/video-ep93xx.h>
25 
26 /* Vertical Frame Timing Registers */
27 #define EP93XXFB_VLINES_TOTAL			0x0000	/* SW locked */
28 #define EP93XXFB_VSYNC				0x0004	/* SW locked */
29 #define EP93XXFB_VACTIVE			0x0008	/* SW locked */
30 #define EP93XXFB_VBLANK				0x0228	/* SW locked */
31 #define EP93XXFB_VCLK				0x000c	/* SW locked */
32 
33 /* Horizontal Frame Timing Registers */
34 #define EP93XXFB_HCLKS_TOTAL			0x0010	/* SW locked */
35 #define EP93XXFB_HSYNC				0x0014	/* SW locked */
36 #define EP93XXFB_HACTIVE			0x0018	/* SW locked */
37 #define EP93XXFB_HBLANK				0x022c	/* SW locked */
38 #define EP93XXFB_HCLK				0x001c	/* SW locked */
39 
40 /* Frame Buffer Memory Configuration Registers */
41 #define EP93XXFB_SCREEN_PAGE			0x0028
42 #define EP93XXFB_SCREEN_HPAGE			0x002c
43 #define EP93XXFB_SCREEN_LINES			0x0030
44 #define EP93XXFB_LINE_LENGTH			0x0034
45 #define EP93XXFB_VLINE_STEP			0x0038
46 #define EP93XXFB_LINE_CARRY			0x003c	/* SW locked */
47 #define EP93XXFB_EOL_OFFSET			0x0230
48 
49 /* Other Video Registers */
50 #define EP93XXFB_BRIGHTNESS			0x0020
51 #define EP93XXFB_ATTRIBS			0x0024	/* SW locked */
52 #define EP93XXFB_SWLOCK				0x007c	/* SW locked */
53 #define EP93XXFB_AC_RATE			0x0214
54 #define EP93XXFB_FIFO_LEVEL			0x0234
55 #define EP93XXFB_PIXELMODE			0x0054
56 #define EP93XXFB_PIXELMODE_32BPP		(0x7 << 0)
57 #define EP93XXFB_PIXELMODE_24BPP		(0x6 << 0)
58 #define EP93XXFB_PIXELMODE_16BPP		(0x4 << 0)
59 #define EP93XXFB_PIXELMODE_8BPP			(0x2 << 0)
60 #define EP93XXFB_PIXELMODE_SHIFT_1P_24B		(0x0 << 3)
61 #define EP93XXFB_PIXELMODE_SHIFT_1P_18B		(0x1 << 3)
62 #define EP93XXFB_PIXELMODE_COLOR_LUT		(0x0 << 10)
63 #define EP93XXFB_PIXELMODE_COLOR_888		(0x4 << 10)
64 #define EP93XXFB_PIXELMODE_COLOR_555		(0x5 << 10)
65 #define EP93XXFB_PARL_IF_OUT			0x0058
66 #define EP93XXFB_PARL_IF_IN			0x005c
67 
68 /* Blink Control Registers */
69 #define EP93XXFB_BLINK_RATE			0x0040
70 #define EP93XXFB_BLINK_MASK			0x0044
71 #define EP93XXFB_BLINK_PATTRN			0x0048
72 #define EP93XXFB_PATTRN_MASK			0x004c
73 #define EP93XXFB_BKGRND_OFFSET			0x0050
74 
75 /* Hardware Cursor Registers */
76 #define EP93XXFB_CURSOR_ADR_START		0x0060
77 #define EP93XXFB_CURSOR_ADR_RESET		0x0064
78 #define EP93XXFB_CURSOR_SIZE			0x0068
79 #define EP93XXFB_CURSOR_COLOR1			0x006c
80 #define EP93XXFB_CURSOR_COLOR2			0x0070
81 #define EP93XXFB_CURSOR_BLINK_COLOR1		0x021c
82 #define EP93XXFB_CURSOR_BLINK_COLOR2		0x0220
83 #define EP93XXFB_CURSOR_XY_LOC			0x0074
84 #define EP93XXFB_CURSOR_DSCAN_HY_LOC		0x0078
85 #define EP93XXFB_CURSOR_BLINK_RATE_CTRL		0x0224
86 
87 /* LUT Registers */
88 #define EP93XXFB_GRY_SCL_LUTR			0x0080
89 #define EP93XXFB_GRY_SCL_LUTG			0x0280
90 #define EP93XXFB_GRY_SCL_LUTB			0x0300
91 #define EP93XXFB_LUT_SW_CONTROL			0x0218
92 #define EP93XXFB_LUT_SW_CONTROL_SWTCH		(1 << 0)
93 #define EP93XXFB_LUT_SW_CONTROL_SSTAT		(1 << 1)
94 #define EP93XXFB_COLOR_LUT			0x0400
95 
96 /* Video Signature Registers */
97 #define EP93XXFB_VID_SIG_RSLT_VAL		0x0200
98 #define EP93XXFB_VID_SIG_CTRL			0x0204
99 #define EP93XXFB_VSIG				0x0208
100 #define EP93XXFB_HSIG				0x020c
101 #define EP93XXFB_SIG_CLR_STR			0x0210
102 
103 /* Minimum / Maximum resolutions supported */
104 #define EP93XXFB_MIN_XRES			64
105 #define EP93XXFB_MIN_YRES			64
106 #define EP93XXFB_MAX_XRES			1024
107 #define EP93XXFB_MAX_YRES			768
108 
109 struct ep93xx_fbi {
110 	struct ep93xxfb_mach_info	*mach_info;
111 	struct clk			*clk;
112 	struct resource			*res;
113 	void __iomem			*mmio_base;
114 	unsigned int			pseudo_palette[256];
115 };
116 
117 static int check_screenpage_bug = 1;
118 module_param(check_screenpage_bug, int, 0644);
119 MODULE_PARM_DESC(check_screenpage_bug,
120 		 "Check for bit 27 screen page bug. Default = 1");
121 
122 static inline unsigned int ep93xxfb_readl(struct ep93xx_fbi *fbi,
123 					  unsigned int off)
124 {
125 	return __raw_readl(fbi->mmio_base + off);
126 }
127 
128 static inline void ep93xxfb_writel(struct ep93xx_fbi *fbi,
129 				   unsigned int val, unsigned int off)
130 {
131 	__raw_writel(val, fbi->mmio_base + off);
132 }
133 
134 /*
135  * Write to one of the locked raster registers.
136  */
137 static inline void ep93xxfb_out_locked(struct ep93xx_fbi *fbi,
138 				       unsigned int val, unsigned int reg)
139 {
140 	/*
141 	 * We don't need a lock or delay here since the raster register
142 	 * block will remain unlocked until the next access.
143 	 */
144 	ep93xxfb_writel(fbi, 0xaa, EP93XXFB_SWLOCK);
145 	ep93xxfb_writel(fbi, val, reg);
146 }
147 
148 static void ep93xxfb_set_video_attribs(struct fb_info *info)
149 {
150 	struct ep93xx_fbi *fbi = info->par;
151 	unsigned int attribs;
152 
153 	attribs = EP93XXFB_ENABLE;
154 	attribs |= fbi->mach_info->flags;
155 	ep93xxfb_out_locked(fbi, attribs, EP93XXFB_ATTRIBS);
156 }
157 
158 static int ep93xxfb_set_pixelmode(struct fb_info *info)
159 {
160 	struct ep93xx_fbi *fbi = info->par;
161 	unsigned int val;
162 
163 	info->var.transp.offset = 0;
164 	info->var.transp.length = 0;
165 
166 	switch (info->var.bits_per_pixel) {
167 	case 8:
168 		val = EP93XXFB_PIXELMODE_8BPP | EP93XXFB_PIXELMODE_COLOR_LUT |
169 			EP93XXFB_PIXELMODE_SHIFT_1P_18B;
170 
171 		info->var.red.offset	= 0;
172 		info->var.red.length	= 8;
173 		info->var.green.offset	= 0;
174 		info->var.green.length	= 8;
175 		info->var.blue.offset	= 0;
176 		info->var.blue.length	= 8;
177 		info->fix.visual 	= FB_VISUAL_PSEUDOCOLOR;
178 		break;
179 
180 	case 16:
181 		val = EP93XXFB_PIXELMODE_16BPP | EP93XXFB_PIXELMODE_COLOR_555 |
182 			EP93XXFB_PIXELMODE_SHIFT_1P_18B;
183 
184 		info->var.red.offset	= 11;
185 		info->var.red.length	= 5;
186 		info->var.green.offset	= 5;
187 		info->var.green.length	= 6;
188 		info->var.blue.offset	= 0;
189 		info->var.blue.length	= 5;
190 		info->fix.visual 	= FB_VISUAL_TRUECOLOR;
191 		break;
192 
193 	case 24:
194 		val = EP93XXFB_PIXELMODE_24BPP | EP93XXFB_PIXELMODE_COLOR_888 |
195 			EP93XXFB_PIXELMODE_SHIFT_1P_24B;
196 
197 		info->var.red.offset	= 16;
198 		info->var.red.length	= 8;
199 		info->var.green.offset	= 8;
200 		info->var.green.length	= 8;
201 		info->var.blue.offset	= 0;
202 		info->var.blue.length	= 8;
203 		info->fix.visual 	= FB_VISUAL_TRUECOLOR;
204 		break;
205 
206 	case 32:
207 		val = EP93XXFB_PIXELMODE_32BPP | EP93XXFB_PIXELMODE_COLOR_888 |
208 			EP93XXFB_PIXELMODE_SHIFT_1P_24B;
209 
210 		info->var.red.offset	= 16;
211 		info->var.red.length	= 8;
212 		info->var.green.offset	= 8;
213 		info->var.green.length	= 8;
214 		info->var.blue.offset	= 0;
215 		info->var.blue.length	= 8;
216 		info->fix.visual 	= FB_VISUAL_TRUECOLOR;
217 		break;
218 
219 	default:
220 		return -EINVAL;
221 	}
222 
223 	ep93xxfb_writel(fbi, val, EP93XXFB_PIXELMODE);
224 	return 0;
225 }
226 
227 static void ep93xxfb_set_timing(struct fb_info *info)
228 {
229 	struct ep93xx_fbi *fbi = info->par;
230 	unsigned int vlines_total, hclks_total, start, stop;
231 
232 	vlines_total = info->var.yres + info->var.upper_margin +
233 		info->var.lower_margin + info->var.vsync_len - 1;
234 
235 	hclks_total = info->var.xres + info->var.left_margin +
236 		info->var.right_margin + info->var.hsync_len - 1;
237 
238 	ep93xxfb_out_locked(fbi, vlines_total, EP93XXFB_VLINES_TOTAL);
239 	ep93xxfb_out_locked(fbi, hclks_total, EP93XXFB_HCLKS_TOTAL);
240 
241 	start = vlines_total;
242 	stop = vlines_total - info->var.vsync_len;
243 	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VSYNC);
244 
245 	start = vlines_total - info->var.vsync_len - info->var.upper_margin;
246 	stop = info->var.lower_margin - 1;
247 	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VBLANK);
248 	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VACTIVE);
249 
250 	start = vlines_total;
251 	stop = vlines_total + 1;
252 	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VCLK);
253 
254 	start = hclks_total;
255 	stop = hclks_total - info->var.hsync_len;
256 	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HSYNC);
257 
258 	start = hclks_total - info->var.hsync_len - info->var.left_margin;
259 	stop = info->var.right_margin - 1;
260 	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HBLANK);
261 	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HACTIVE);
262 
263 	start = hclks_total;
264 	stop = hclks_total;
265 	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HCLK);
266 
267 	ep93xxfb_out_locked(fbi, 0x0, EP93XXFB_LINE_CARRY);
268 }
269 
270 static int ep93xxfb_set_par(struct fb_info *info)
271 {
272 	struct ep93xx_fbi *fbi = info->par;
273 
274 	clk_set_rate(fbi->clk, 1000 * PICOS2KHZ(info->var.pixclock));
275 
276 	ep93xxfb_set_timing(info);
277 
278 	info->fix.line_length = info->var.xres_virtual *
279 		info->var.bits_per_pixel / 8;
280 
281 	ep93xxfb_writel(fbi, info->fix.smem_start, EP93XXFB_SCREEN_PAGE);
282 	ep93xxfb_writel(fbi, info->var.yres - 1, EP93XXFB_SCREEN_LINES);
283 	ep93xxfb_writel(fbi, ((info->var.xres * info->var.bits_per_pixel)
284 			      / 32) - 1, EP93XXFB_LINE_LENGTH);
285 	ep93xxfb_writel(fbi, info->fix.line_length / 4, EP93XXFB_VLINE_STEP);
286 	ep93xxfb_set_video_attribs(info);
287 	return 0;
288 }
289 
290 static int ep93xxfb_check_var(struct fb_var_screeninfo *var,
291 			      struct fb_info *info)
292 {
293 	int err;
294 
295 	err = ep93xxfb_set_pixelmode(info);
296 	if (err)
297 		return err;
298 
299 	var->xres = max_t(unsigned int, var->xres, EP93XXFB_MIN_XRES);
300 	var->xres = min_t(unsigned int, var->xres, EP93XXFB_MAX_XRES);
301 	var->xres_virtual = max(var->xres_virtual, var->xres);
302 
303 	var->yres = max_t(unsigned int, var->yres, EP93XXFB_MIN_YRES);
304 	var->yres = min_t(unsigned int, var->yres, EP93XXFB_MAX_YRES);
305 	var->yres_virtual = max(var->yres_virtual, var->yres);
306 
307 	return 0;
308 }
309 
310 static int ep93xxfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
311 {
312 	unsigned int offset = vma->vm_pgoff << PAGE_SHIFT;
313 
314 	if (offset < info->fix.smem_len) {
315 		return dma_mmap_wc(info->dev, vma, info->screen_base,
316 				   info->fix.smem_start, info->fix.smem_len);
317 	}
318 
319 	return -EINVAL;
320 }
321 
322 static int ep93xxfb_blank(int blank_mode, struct fb_info *info)
323 {
324 	struct ep93xx_fbi *fbi = info->par;
325 	unsigned int attribs = ep93xxfb_readl(fbi, EP93XXFB_ATTRIBS);
326 
327 	if (blank_mode) {
328 		if (fbi->mach_info->blank)
329 			fbi->mach_info->blank(blank_mode, info);
330 		ep93xxfb_out_locked(fbi, attribs & ~EP93XXFB_ENABLE,
331 				    EP93XXFB_ATTRIBS);
332 		clk_disable(fbi->clk);
333 	} else {
334 		clk_enable(fbi->clk);
335 		ep93xxfb_out_locked(fbi, attribs | EP93XXFB_ENABLE,
336 				    EP93XXFB_ATTRIBS);
337 		if (fbi->mach_info->blank)
338 			fbi->mach_info->blank(blank_mode, info);
339 	}
340 
341 	return 0;
342 }
343 
344 static inline int ep93xxfb_convert_color(int val, int width)
345 {
346 	return ((val << width) + 0x7fff - val) >> 16;
347 }
348 
349 static int ep93xxfb_setcolreg(unsigned int regno, unsigned int red,
350 			      unsigned int green, unsigned int blue,
351 			      unsigned int transp, struct fb_info *info)
352 {
353 	struct ep93xx_fbi *fbi = info->par;
354 	unsigned int *pal = info->pseudo_palette;
355 	unsigned int ctrl, i, rgb, lut_current, lut_stat;
356 
357 	switch (info->fix.visual) {
358 	case FB_VISUAL_PSEUDOCOLOR:
359 		if (regno > 255)
360 			return 1;
361 		rgb = ((red & 0xff00) << 8) | (green & 0xff00) |
362 			((blue & 0xff00) >> 8);
363 
364 		pal[regno] = rgb;
365 		ep93xxfb_writel(fbi, rgb, (EP93XXFB_COLOR_LUT + (regno << 2)));
366 		ctrl = ep93xxfb_readl(fbi, EP93XXFB_LUT_SW_CONTROL);
367 		lut_stat = !!(ctrl & EP93XXFB_LUT_SW_CONTROL_SSTAT);
368 		lut_current = !!(ctrl & EP93XXFB_LUT_SW_CONTROL_SWTCH);
369 
370 		if (lut_stat == lut_current) {
371 			for (i = 0; i < 256; i++) {
372 				ep93xxfb_writel(fbi, pal[i],
373 					EP93XXFB_COLOR_LUT + (i << 2));
374 			}
375 
376 			ep93xxfb_writel(fbi,
377 					ctrl ^ EP93XXFB_LUT_SW_CONTROL_SWTCH,
378 					EP93XXFB_LUT_SW_CONTROL);
379 		}
380 		break;
381 
382 	case FB_VISUAL_TRUECOLOR:
383 		if (regno > 16)
384 			return 1;
385 
386 		red = ep93xxfb_convert_color(red, info->var.red.length);
387 		green = ep93xxfb_convert_color(green, info->var.green.length);
388 		blue = ep93xxfb_convert_color(blue, info->var.blue.length);
389 		transp = ep93xxfb_convert_color(transp,
390 						info->var.transp.length);
391 
392 		pal[regno] = (red << info->var.red.offset) |
393 			(green << info->var.green.offset) |
394 			(blue << info->var.blue.offset) |
395 			(transp << info->var.transp.offset);
396 		break;
397 
398 	default:
399 		return 1;
400 	}
401 
402 	return 0;
403 }
404 
405 static struct fb_ops ep93xxfb_ops = {
406 	.owner		= THIS_MODULE,
407 	.fb_check_var	= ep93xxfb_check_var,
408 	.fb_set_par	= ep93xxfb_set_par,
409 	.fb_blank	= ep93xxfb_blank,
410 	.fb_fillrect	= cfb_fillrect,
411 	.fb_copyarea	= cfb_copyarea,
412 	.fb_imageblit	= cfb_imageblit,
413 	.fb_setcolreg	= ep93xxfb_setcolreg,
414 	.fb_mmap	= ep93xxfb_mmap,
415 };
416 
417 static int ep93xxfb_alloc_videomem(struct fb_info *info)
418 {
419 	char __iomem *virt_addr;
420 	dma_addr_t phys_addr;
421 	unsigned int fb_size;
422 
423 	/* Maximum 16bpp -> used memory is maximum x*y*2 bytes */
424 	fb_size = EP93XXFB_MAX_XRES * EP93XXFB_MAX_YRES * 2;
425 
426 	virt_addr = dma_alloc_wc(info->dev, fb_size, &phys_addr, GFP_KERNEL);
427 	if (!virt_addr)
428 		return -ENOMEM;
429 
430 	/*
431 	 * There is a bug in the ep93xx framebuffer which causes problems
432 	 * if bit 27 of the physical address is set.
433 	 * See: http://marc.info/?l=linux-arm-kernel&m=110061245502000&w=2
434 	 * There does not seem to be any official errata for this, but I
435 	 * have confirmed the problem exists on my hardware (ep9315) at
436 	 * least.
437 	 */
438 	if (check_screenpage_bug && phys_addr & (1 << 27)) {
439 		dev_err(info->dev, "ep93xx framebuffer bug. phys addr (0x%x) "
440 			"has bit 27 set: cannot init framebuffer\n",
441 			phys_addr);
442 
443 		dma_free_coherent(info->dev, fb_size, virt_addr, phys_addr);
444 		return -ENOMEM;
445 	}
446 
447 	info->fix.smem_start = phys_addr;
448 	info->fix.smem_len = fb_size;
449 	info->screen_base = virt_addr;
450 
451 	return 0;
452 }
453 
454 static void ep93xxfb_dealloc_videomem(struct fb_info *info)
455 {
456 	if (info->screen_base)
457 		dma_free_coherent(info->dev, info->fix.smem_len,
458 				  info->screen_base, info->fix.smem_start);
459 }
460 
461 static int ep93xxfb_probe(struct platform_device *pdev)
462 {
463 	struct ep93xxfb_mach_info *mach_info = dev_get_platdata(&pdev->dev);
464 	struct fb_info *info;
465 	struct ep93xx_fbi *fbi;
466 	struct resource *res;
467 	char *video_mode;
468 	int err;
469 
470 	if (!mach_info)
471 		return -EINVAL;
472 
473 	info = framebuffer_alloc(sizeof(struct ep93xx_fbi), &pdev->dev);
474 	if (!info)
475 		return -ENOMEM;
476 
477 	info->dev = &pdev->dev;
478 	platform_set_drvdata(pdev, info);
479 	fbi = info->par;
480 	fbi->mach_info = mach_info;
481 
482 	err = fb_alloc_cmap(&info->cmap, 256, 0);
483 	if (err)
484 		goto failed_cmap;
485 
486 	err = ep93xxfb_alloc_videomem(info);
487 	if (err)
488 		goto failed_videomem;
489 
490 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
491 	if (!res) {
492 		err = -ENXIO;
493 		goto failed_resource;
494 	}
495 
496 	/*
497 	 * FIXME - We don't do a request_mem_region here because we are
498 	 * sharing the register space with the backlight driver (see
499 	 * drivers/video/backlight/ep93xx_bl.c) and doing so will cause
500 	 * the second loaded driver to return -EBUSY.
501 	 *
502 	 * NOTE: No locking is required; the backlight does not touch
503 	 * any of the framebuffer registers.
504 	 */
505 	fbi->res = res;
506 	fbi->mmio_base = devm_ioremap(&pdev->dev, res->start,
507 				      resource_size(res));
508 	if (!fbi->mmio_base) {
509 		err = -ENXIO;
510 		goto failed_resource;
511 	}
512 
513 	strcpy(info->fix.id, pdev->name);
514 	info->fbops		= &ep93xxfb_ops;
515 	info->fix.type		= FB_TYPE_PACKED_PIXELS;
516 	info->fix.accel		= FB_ACCEL_NONE;
517 	info->var.activate	= FB_ACTIVATE_NOW;
518 	info->var.vmode		= FB_VMODE_NONINTERLACED;
519 	info->flags		= FBINFO_DEFAULT;
520 	info->node		= -1;
521 	info->state		= FBINFO_STATE_RUNNING;
522 	info->pseudo_palette	= &fbi->pseudo_palette;
523 
524 	fb_get_options("ep93xx-fb", &video_mode);
525 	err = fb_find_mode(&info->var, info, video_mode,
526 			   NULL, 0, NULL, 16);
527 	if (err == 0) {
528 		dev_err(info->dev, "No suitable video mode found\n");
529 		err = -EINVAL;
530 		goto failed_resource;
531 	}
532 
533 	if (mach_info->setup) {
534 		err = mach_info->setup(pdev);
535 		if (err)
536 			goto failed_resource;
537 	}
538 
539 	err = ep93xxfb_check_var(&info->var, info);
540 	if (err)
541 		goto failed_check;
542 
543 	fbi->clk = devm_clk_get(&pdev->dev, NULL);
544 	if (IS_ERR(fbi->clk)) {
545 		err = PTR_ERR(fbi->clk);
546 		fbi->clk = NULL;
547 		goto failed_check;
548 	}
549 
550 	ep93xxfb_set_par(info);
551 	clk_enable(fbi->clk);
552 
553 	err = register_framebuffer(info);
554 	if (err)
555 		goto failed_check;
556 
557 	dev_info(info->dev, "registered. Mode = %dx%d-%d\n",
558 		 info->var.xres, info->var.yres, info->var.bits_per_pixel);
559 	return 0;
560 
561 failed_check:
562 	if (fbi->mach_info->teardown)
563 		fbi->mach_info->teardown(pdev);
564 failed_resource:
565 	ep93xxfb_dealloc_videomem(info);
566 failed_videomem:
567 	fb_dealloc_cmap(&info->cmap);
568 failed_cmap:
569 	kfree(info);
570 
571 	return err;
572 }
573 
574 static int ep93xxfb_remove(struct platform_device *pdev)
575 {
576 	struct fb_info *info = platform_get_drvdata(pdev);
577 	struct ep93xx_fbi *fbi = info->par;
578 
579 	unregister_framebuffer(info);
580 	clk_disable(fbi->clk);
581 	ep93xxfb_dealloc_videomem(info);
582 	fb_dealloc_cmap(&info->cmap);
583 
584 	if (fbi->mach_info->teardown)
585 		fbi->mach_info->teardown(pdev);
586 
587 	kfree(info);
588 
589 	return 0;
590 }
591 
592 static struct platform_driver ep93xxfb_driver = {
593 	.probe		= ep93xxfb_probe,
594 	.remove		= ep93xxfb_remove,
595 	.driver = {
596 		.name	= "ep93xx-fb",
597 	},
598 };
599 module_platform_driver(ep93xxfb_driver);
600 
601 MODULE_DESCRIPTION("EP93XX Framebuffer Driver");
602 MODULE_ALIAS("platform:ep93xx-fb");
603 MODULE_AUTHOR("Ryan Mallon, "
604 	      "H Hartley Sweeten <hsweeten@visionengravers.com");
605 MODULE_LICENSE("GPL");
606