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1 /*
2  * xilinxfb.c
3  *
4  * Xilinx TFT LCD frame buffer driver
5  *
6  * Author: MontaVista Software, Inc.
7  *         source@mvista.com
8  *
9  * 2002-2007 (c) MontaVista Software, Inc.
10  * 2007 (c) Secret Lab Technologies, Ltd.
11  *
12  * This file is licensed under the terms of the GNU General Public License
13  * version 2.  This program is licensed "as is" without any warranty of any
14  * kind, whether express or implied.
15  */
16 
17 /*
18  * This driver was based on au1100fb.c by MontaVista rewritten for 2.6
19  * by Embedded Alley Solutions <source@embeddedalley.com>, which in turn
20  * was based on skeletonfb.c, Skeleton for a frame buffer device by
21  * Geert Uytterhoeven.
22  */
23 
24 #include <linux/device.h>
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/errno.h>
28 #include <linux/string.h>
29 #include <linux/mm.h>
30 #include <linux/fb.h>
31 #include <linux/init.h>
32 #include <linux/dma-mapping.h>
33 #include <linux/platform_device.h>
34 #if defined(CONFIG_OF)
35 #include <linux/of_device.h>
36 #include <linux/of_platform.h>
37 #endif
38 #include <asm/io.h>
39 #include <linux/xilinxfb.h>
40 
41 #define DRIVER_NAME		"xilinxfb"
42 #define DRIVER_DESCRIPTION	"Xilinx TFT LCD frame buffer driver"
43 
44 /*
45  * Xilinx calls it "PLB TFT LCD Controller" though it can also be used for
46  * the VGA port on the Xilinx ML40x board. This is a hardware display controller
47  * for a 640x480 resolution TFT or VGA screen.
48  *
49  * The interface to the framebuffer is nice and simple.  There are two
50  * control registers.  The first tells the LCD interface where in memory
51  * the frame buffer is (only the 11 most significant bits are used, so
52  * don't start thinking about scrolling).  The second allows the LCD to
53  * be turned on or off as well as rotated 180 degrees.
54  */
55 #define NUM_REGS	2
56 #define REG_FB_ADDR	0
57 #define REG_CTRL	1
58 #define REG_CTRL_ENABLE	 0x0001
59 #define REG_CTRL_ROTATE	 0x0002
60 
61 /*
62  * The hardware only handles a single mode: 640x480 24 bit true
63  * color. Each pixel gets a word (32 bits) of memory.  Within each word,
64  * the 8 most significant bits are ignored, the next 8 bits are the red
65  * level, the next 8 bits are the green level and the 8 least
66  * significant bits are the blue level.  Each row of the LCD uses 1024
67  * words, but only the first 640 pixels are displayed with the other 384
68  * words being ignored.  There are 480 rows.
69  */
70 #define BYTES_PER_PIXEL	4
71 #define BITS_PER_PIXEL	(BYTES_PER_PIXEL * 8)
72 
73 #define RED_SHIFT	16
74 #define GREEN_SHIFT	8
75 #define BLUE_SHIFT	0
76 
77 #define PALETTE_ENTRIES_NO	16	/* passed to fb_alloc_cmap() */
78 
79 /*
80  * Default xilinxfb configuration
81  */
82 static struct xilinxfb_platform_data xilinx_fb_default_pdata = {
83 	.xres = 640,
84 	.yres = 480,
85 	.xvirt = 1024,
86 	.yvirt = 480,
87 };
88 
89 /*
90  * Here are the default fb_fix_screeninfo and fb_var_screeninfo structures
91  */
92 static struct fb_fix_screeninfo xilinx_fb_fix = {
93 	.id =		"Xilinx",
94 	.type =		FB_TYPE_PACKED_PIXELS,
95 	.visual =	FB_VISUAL_TRUECOLOR,
96 	.accel =	FB_ACCEL_NONE
97 };
98 
99 static struct fb_var_screeninfo xilinx_fb_var = {
100 	.bits_per_pixel =	BITS_PER_PIXEL,
101 
102 	.red =		{ RED_SHIFT, 8, 0 },
103 	.green =	{ GREEN_SHIFT, 8, 0 },
104 	.blue =		{ BLUE_SHIFT, 8, 0 },
105 	.transp =	{ 0, 0, 0 },
106 
107 	.activate =	FB_ACTIVATE_NOW
108 };
109 
110 struct xilinxfb_drvdata {
111 
112 	struct fb_info	info;		/* FB driver info record */
113 
114 	u32		regs_phys;	/* phys. address of the control registers */
115 	u32 __iomem	*regs;		/* virt. address of the control registers */
116 
117 	void		*fb_virt;	/* virt. address of the frame buffer */
118 	dma_addr_t	fb_phys;	/* phys. address of the frame buffer */
119 	int		fb_alloced;	/* Flag, was the fb memory alloced? */
120 
121 	u32		reg_ctrl_default;
122 
123 	u32		pseudo_palette[PALETTE_ENTRIES_NO];
124 					/* Fake palette of 16 colors */
125 };
126 
127 #define to_xilinxfb_drvdata(_info) \
128 	container_of(_info, struct xilinxfb_drvdata, info)
129 
130 /*
131  * The LCD controller has DCR interface to its registers, but all
132  * the boards and configurations the driver has been tested with
133  * use opb2dcr bridge. So the registers are seen as memory mapped.
134  * This macro is to make it simple to add the direct DCR access
135  * when it's needed.
136  */
137 #define xilinx_fb_out_be32(driverdata, offset, val) \
138 	out_be32(driverdata->regs + offset, val)
139 
140 static int
xilinx_fb_setcolreg(unsigned regno,unsigned red,unsigned green,unsigned blue,unsigned transp,struct fb_info * fbi)141 xilinx_fb_setcolreg(unsigned regno, unsigned red, unsigned green, unsigned blue,
142 	unsigned transp, struct fb_info *fbi)
143 {
144 	u32 *palette = fbi->pseudo_palette;
145 
146 	if (regno >= PALETTE_ENTRIES_NO)
147 		return -EINVAL;
148 
149 	if (fbi->var.grayscale) {
150 		/* Convert color to grayscale.
151 		 * grayscale = 0.30*R + 0.59*G + 0.11*B */
152 		red = green = blue =
153 			(red * 77 + green * 151 + blue * 28 + 127) >> 8;
154 	}
155 
156 	/* fbi->fix.visual is always FB_VISUAL_TRUECOLOR */
157 
158 	/* We only handle 8 bits of each color. */
159 	red >>= 8;
160 	green >>= 8;
161 	blue >>= 8;
162 	palette[regno] = (red << RED_SHIFT) | (green << GREEN_SHIFT) |
163 			 (blue << BLUE_SHIFT);
164 
165 	return 0;
166 }
167 
168 static int
xilinx_fb_blank(int blank_mode,struct fb_info * fbi)169 xilinx_fb_blank(int blank_mode, struct fb_info *fbi)
170 {
171 	struct xilinxfb_drvdata *drvdata = to_xilinxfb_drvdata(fbi);
172 
173 	switch (blank_mode) {
174 	case FB_BLANK_UNBLANK:
175 		/* turn on panel */
176 		xilinx_fb_out_be32(drvdata, REG_CTRL, drvdata->reg_ctrl_default);
177 		break;
178 
179 	case FB_BLANK_NORMAL:
180 	case FB_BLANK_VSYNC_SUSPEND:
181 	case FB_BLANK_HSYNC_SUSPEND:
182 	case FB_BLANK_POWERDOWN:
183 		/* turn off panel */
184 		xilinx_fb_out_be32(drvdata, REG_CTRL, 0);
185 	default:
186 		break;
187 
188 	}
189 	return 0; /* success */
190 }
191 
192 static struct fb_ops xilinxfb_ops =
193 {
194 	.owner			= THIS_MODULE,
195 	.fb_setcolreg		= xilinx_fb_setcolreg,
196 	.fb_blank		= xilinx_fb_blank,
197 	.fb_fillrect		= cfb_fillrect,
198 	.fb_copyarea		= cfb_copyarea,
199 	.fb_imageblit		= cfb_imageblit,
200 };
201 
202 /* ---------------------------------------------------------------------
203  * Bus independent setup/teardown
204  */
205 
xilinxfb_assign(struct device * dev,unsigned long physaddr,struct xilinxfb_platform_data * pdata)206 static int xilinxfb_assign(struct device *dev, unsigned long physaddr,
207 			   struct xilinxfb_platform_data *pdata)
208 {
209 	struct xilinxfb_drvdata *drvdata;
210 	int rc;
211 	int fbsize = pdata->xvirt * pdata->yvirt * BYTES_PER_PIXEL;
212 
213 	/* Allocate the driver data region */
214 	drvdata = kzalloc(sizeof(*drvdata), GFP_KERNEL);
215 	if (!drvdata) {
216 		dev_err(dev, "Couldn't allocate device private record\n");
217 		return -ENOMEM;
218 	}
219 	dev_set_drvdata(dev, drvdata);
220 
221 	/* Map the control registers in */
222 	if (!request_mem_region(physaddr, 8, DRIVER_NAME)) {
223 		dev_err(dev, "Couldn't lock memory region at 0x%08lX\n",
224 			physaddr);
225 		rc = -ENODEV;
226 		goto err_region;
227 	}
228 	drvdata->regs_phys = physaddr;
229 	drvdata->regs = ioremap(physaddr, 8);
230 	if (!drvdata->regs) {
231 		dev_err(dev, "Couldn't lock memory region at 0x%08lX\n",
232 			physaddr);
233 		rc = -ENODEV;
234 		goto err_map;
235 	}
236 
237 	/* Allocate the framebuffer memory */
238 	if (pdata->fb_phys) {
239 		drvdata->fb_phys = pdata->fb_phys;
240 		drvdata->fb_virt = ioremap(pdata->fb_phys, fbsize);
241 	} else {
242 		drvdata->fb_alloced = 1;
243 		drvdata->fb_virt = dma_alloc_coherent(dev, PAGE_ALIGN(fbsize),
244 					&drvdata->fb_phys, GFP_KERNEL);
245 	}
246 
247 	if (!drvdata->fb_virt) {
248 		dev_err(dev, "Could not allocate frame buffer memory\n");
249 		rc = -ENOMEM;
250 		goto err_fbmem;
251 	}
252 
253 	/* Clear (turn to black) the framebuffer */
254 	memset_io((void __iomem *)drvdata->fb_virt, 0, fbsize);
255 
256 	/* Tell the hardware where the frame buffer is */
257 	xilinx_fb_out_be32(drvdata, REG_FB_ADDR, drvdata->fb_phys);
258 
259 	/* Turn on the display */
260 	drvdata->reg_ctrl_default = REG_CTRL_ENABLE;
261 	if (pdata->rotate_screen)
262 		drvdata->reg_ctrl_default |= REG_CTRL_ROTATE;
263 	xilinx_fb_out_be32(drvdata, REG_CTRL, drvdata->reg_ctrl_default);
264 
265 	/* Fill struct fb_info */
266 	drvdata->info.device = dev;
267 	drvdata->info.screen_base = (void __iomem *)drvdata->fb_virt;
268 	drvdata->info.fbops = &xilinxfb_ops;
269 	drvdata->info.fix = xilinx_fb_fix;
270 	drvdata->info.fix.smem_start = drvdata->fb_phys;
271 	drvdata->info.fix.smem_len = fbsize;
272 	drvdata->info.fix.line_length = pdata->xvirt * BYTES_PER_PIXEL;
273 
274 	drvdata->info.pseudo_palette = drvdata->pseudo_palette;
275 	drvdata->info.flags = FBINFO_DEFAULT;
276 	drvdata->info.var = xilinx_fb_var;
277 	drvdata->info.var.height = pdata->screen_height_mm;
278 	drvdata->info.var.width = pdata->screen_width_mm;
279 	drvdata->info.var.xres = pdata->xres;
280 	drvdata->info.var.yres = pdata->yres;
281 	drvdata->info.var.xres_virtual = pdata->xvirt;
282 	drvdata->info.var.yres_virtual = pdata->yvirt;
283 
284 	/* Allocate a colour map */
285 	rc = fb_alloc_cmap(&drvdata->info.cmap, PALETTE_ENTRIES_NO, 0);
286 	if (rc) {
287 		dev_err(dev, "Fail to allocate colormap (%d entries)\n",
288 			PALETTE_ENTRIES_NO);
289 		goto err_cmap;
290 	}
291 
292 	/* Register new frame buffer */
293 	rc = register_framebuffer(&drvdata->info);
294 	if (rc) {
295 		dev_err(dev, "Could not register frame buffer\n");
296 		goto err_regfb;
297 	}
298 
299 	/* Put a banner in the log (for DEBUG) */
300 	dev_dbg(dev, "regs: phys=%lx, virt=%p\n", physaddr, drvdata->regs);
301 	dev_dbg(dev, "fb: phys=%llx, virt=%p, size=%x\n",
302 		(unsigned long long) drvdata->fb_phys, drvdata->fb_virt,
303 		fbsize);
304 
305 	return 0;	/* success */
306 
307 err_regfb:
308 	fb_dealloc_cmap(&drvdata->info.cmap);
309 
310 err_cmap:
311 	if (drvdata->fb_alloced)
312 		dma_free_coherent(dev, PAGE_ALIGN(fbsize), drvdata->fb_virt,
313 			drvdata->fb_phys);
314 	/* Turn off the display */
315 	xilinx_fb_out_be32(drvdata, REG_CTRL, 0);
316 
317 err_fbmem:
318 	iounmap(drvdata->regs);
319 
320 err_map:
321 	release_mem_region(physaddr, 8);
322 
323 err_region:
324 	kfree(drvdata);
325 	dev_set_drvdata(dev, NULL);
326 
327 	return rc;
328 }
329 
xilinxfb_release(struct device * dev)330 static int xilinxfb_release(struct device *dev)
331 {
332 	struct xilinxfb_drvdata *drvdata = dev_get_drvdata(dev);
333 
334 #if !defined(CONFIG_FRAMEBUFFER_CONSOLE) && defined(CONFIG_LOGO)
335 	xilinx_fb_blank(VESA_POWERDOWN, &drvdata->info);
336 #endif
337 
338 	unregister_framebuffer(&drvdata->info);
339 
340 	fb_dealloc_cmap(&drvdata->info.cmap);
341 
342 	if (drvdata->fb_alloced)
343 		dma_free_coherent(dev, PAGE_ALIGN(drvdata->info.fix.smem_len),
344 				  drvdata->fb_virt, drvdata->fb_phys);
345 
346 	/* Turn off the display */
347 	xilinx_fb_out_be32(drvdata, REG_CTRL, 0);
348 	iounmap(drvdata->regs);
349 
350 	release_mem_region(drvdata->regs_phys, 8);
351 
352 	kfree(drvdata);
353 	dev_set_drvdata(dev, NULL);
354 
355 	return 0;
356 }
357 
358 /* ---------------------------------------------------------------------
359  * Platform bus binding
360  */
361 
362 static int
xilinxfb_platform_probe(struct platform_device * pdev)363 xilinxfb_platform_probe(struct platform_device *pdev)
364 {
365 	struct xilinxfb_platform_data *pdata;
366 	struct resource *res;
367 
368 	/* Find the registers address */
369 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
370 	if (!res) {
371 		dev_err(&pdev->dev, "Couldn't get registers resource\n");
372 		return -ENODEV;
373 	}
374 
375 	/* If a pdata structure is provided, then extract the parameters */
376 	pdata = &xilinx_fb_default_pdata;
377 	if (pdev->dev.platform_data) {
378 		pdata = pdev->dev.platform_data;
379 		if (!pdata->xres)
380 			pdata->xres = xilinx_fb_default_pdata.xres;
381 		if (!pdata->yres)
382 			pdata->yres = xilinx_fb_default_pdata.yres;
383 		if (!pdata->xvirt)
384 			pdata->xvirt = xilinx_fb_default_pdata.xvirt;
385 		if (!pdata->yvirt)
386 			pdata->yvirt = xilinx_fb_default_pdata.yvirt;
387 	}
388 
389 	return xilinxfb_assign(&pdev->dev, res->start, pdata);
390 }
391 
392 static int
xilinxfb_platform_remove(struct platform_device * pdev)393 xilinxfb_platform_remove(struct platform_device *pdev)
394 {
395 	return xilinxfb_release(&pdev->dev);
396 }
397 
398 
399 static struct platform_driver xilinxfb_platform_driver = {
400 	.probe		= xilinxfb_platform_probe,
401 	.remove		= xilinxfb_platform_remove,
402 	.driver = {
403 		.owner = THIS_MODULE,
404 		.name = DRIVER_NAME,
405 	},
406 };
407 
408 /* ---------------------------------------------------------------------
409  * OF bus binding
410  */
411 
412 #if defined(CONFIG_OF)
413 static int __devinit
xilinxfb_of_probe(struct of_device * op,const struct of_device_id * match)414 xilinxfb_of_probe(struct of_device *op, const struct of_device_id *match)
415 {
416 	struct resource res;
417 	const u32 *prop;
418 	struct xilinxfb_platform_data pdata;
419 	int size, rc;
420 
421 	/* Copy with the default pdata (not a ptr reference!) */
422 	pdata = xilinx_fb_default_pdata;
423 
424 	dev_dbg(&op->dev, "xilinxfb_of_probe(%p, %p)\n", op, match);
425 
426 	rc = of_address_to_resource(op->node, 0, &res);
427 	if (rc) {
428 		dev_err(&op->dev, "invalid address\n");
429 		return rc;
430 	}
431 
432 	prop = of_get_property(op->node, "phys-size", &size);
433 	if ((prop) && (size >= sizeof(u32)*2)) {
434 		pdata.screen_width_mm = prop[0];
435 		pdata.screen_height_mm = prop[1];
436 	}
437 
438 	prop = of_get_property(op->node, "resolution", &size);
439 	if ((prop) && (size >= sizeof(u32)*2)) {
440 		pdata.xres = prop[0];
441 		pdata.yres = prop[1];
442 	}
443 
444 	prop = of_get_property(op->node, "virtual-resolution", &size);
445 	if ((prop) && (size >= sizeof(u32)*2)) {
446 		pdata.xvirt = prop[0];
447 		pdata.yvirt = prop[1];
448 	}
449 
450 	if (of_find_property(op->node, "rotate-display", NULL))
451 		pdata.rotate_screen = 1;
452 
453 	return xilinxfb_assign(&op->dev, res.start, &pdata);
454 }
455 
xilinxfb_of_remove(struct of_device * op)456 static int __devexit xilinxfb_of_remove(struct of_device *op)
457 {
458 	return xilinxfb_release(&op->dev);
459 }
460 
461 /* Match table for of_platform binding */
462 static struct of_device_id xilinxfb_of_match[] __devinitdata = {
463 	{ .compatible = "xlnx,plb-tft-cntlr-ref-1.00.a", },
464 	{},
465 };
466 MODULE_DEVICE_TABLE(of, xilinxfb_of_match);
467 
468 static struct of_platform_driver xilinxfb_of_driver = {
469 	.owner = THIS_MODULE,
470 	.name = DRIVER_NAME,
471 	.match_table = xilinxfb_of_match,
472 	.probe = xilinxfb_of_probe,
473 	.remove = __devexit_p(xilinxfb_of_remove),
474 	.driver = {
475 		.name = DRIVER_NAME,
476 	},
477 };
478 
479 /* Registration helpers to keep the number of #ifdefs to a minimum */
xilinxfb_of_register(void)480 static inline int __init xilinxfb_of_register(void)
481 {
482 	pr_debug("xilinxfb: calling of_register_platform_driver()\n");
483 	return of_register_platform_driver(&xilinxfb_of_driver);
484 }
485 
xilinxfb_of_unregister(void)486 static inline void __exit xilinxfb_of_unregister(void)
487 {
488 	of_unregister_platform_driver(&xilinxfb_of_driver);
489 }
490 #else /* CONFIG_OF */
491 /* CONFIG_OF not enabled; do nothing helpers */
xilinxfb_of_register(void)492 static inline int __init xilinxfb_of_register(void) { return 0; }
xilinxfb_of_unregister(void)493 static inline void __exit xilinxfb_of_unregister(void) { }
494 #endif /* CONFIG_OF */
495 
496 /* ---------------------------------------------------------------------
497  * Module setup and teardown
498  */
499 
500 static int __init
xilinxfb_init(void)501 xilinxfb_init(void)
502 {
503 	int rc;
504 	rc = xilinxfb_of_register();
505 	if (rc)
506 		return rc;
507 
508 	rc = platform_driver_register(&xilinxfb_platform_driver);
509 	if (rc)
510 		xilinxfb_of_unregister();
511 
512 	return rc;
513 }
514 
515 static void __exit
xilinxfb_cleanup(void)516 xilinxfb_cleanup(void)
517 {
518 	platform_driver_unregister(&xilinxfb_platform_driver);
519 	xilinxfb_of_unregister();
520 }
521 
522 module_init(xilinxfb_init);
523 module_exit(xilinxfb_cleanup);
524 
525 MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>");
526 MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
527 MODULE_LICENSE("GPL");
528