1 /*
2  *  linux/drivers/video/vt8500lcdfb.c
3  *
4  *  Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
5  *
6  * Based on skeletonfb.c and pxafb.c
7  *
8  * This software is licensed under the terms of the GNU General Public
9  * License version 2, as published by the Free Software Foundation, and
10  * may be copied, distributed, and modified under those terms.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  */
17 
18 #include <linux/delay.h>
19 #include <linux/dma-mapping.h>
20 #include <linux/errno.h>
21 #include <linux/fb.h>
22 #include <linux/init.h>
23 #include <linux/interrupt.h>
24 #include <linux/io.h>
25 #include <linux/kernel.h>
26 #include <linux/mm.h>
27 #include <linux/module.h>
28 #include <linux/platform_device.h>
29 #include <linux/slab.h>
30 #include <linux/string.h>
31 #include <linux/wait.h>
32 #include <video/of_display_timing.h>
33 
34 #include "vt8500lcdfb.h"
35 #include "wmt_ge_rops.h"
36 
37 #ifdef CONFIG_OF
38 #include <linux/of.h>
39 #include <linux/of_fdt.h>
40 #include <linux/memblock.h>
41 #endif
42 
43 
44 #define to_vt8500lcd_info(__info) container_of(__info, \
45 						struct vt8500lcd_info, fb)
46 
47 static int vt8500lcd_set_par(struct fb_info *info)
48 {
49 	struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
50 	int reg_bpp = 5; /* 16bpp */
51 	int i;
52 	unsigned long control0;
53 
54 	if (!fbi)
55 		return -EINVAL;
56 
57 	if (info->var.bits_per_pixel <= 8) {
58 		/* palettized */
59 		info->var.red.offset    = 0;
60 		info->var.red.length    = info->var.bits_per_pixel;
61 		info->var.red.msb_right = 0;
62 
63 		info->var.green.offset  = 0;
64 		info->var.green.length  = info->var.bits_per_pixel;
65 		info->var.green.msb_right = 0;
66 
67 		info->var.blue.offset   = 0;
68 		info->var.blue.length   = info->var.bits_per_pixel;
69 		info->var.blue.msb_right = 0;
70 
71 		info->var.transp.offset = 0;
72 		info->var.transp.length = 0;
73 		info->var.transp.msb_right = 0;
74 
75 		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
76 		info->fix.line_length = info->var.xres_virtual /
77 						(8/info->var.bits_per_pixel);
78 	} else {
79 		/* non-palettized */
80 		info->var.transp.offset = 0;
81 		info->var.transp.length = 0;
82 		info->var.transp.msb_right = 0;
83 
84 		if (info->var.bits_per_pixel == 16) {
85 			/* RGB565 */
86 			info->var.red.offset = 11;
87 			info->var.red.length = 5;
88 			info->var.red.msb_right = 0;
89 			info->var.green.offset = 5;
90 			info->var.green.length = 6;
91 			info->var.green.msb_right = 0;
92 			info->var.blue.offset = 0;
93 			info->var.blue.length = 5;
94 			info->var.blue.msb_right = 0;
95 		} else {
96 			/* Equal depths per channel */
97 			info->var.red.offset = info->var.bits_per_pixel
98 							* 2 / 3;
99 			info->var.red.length = info->var.bits_per_pixel / 3;
100 			info->var.red.msb_right = 0;
101 			info->var.green.offset = info->var.bits_per_pixel / 3;
102 			info->var.green.length = info->var.bits_per_pixel / 3;
103 			info->var.green.msb_right = 0;
104 			info->var.blue.offset = 0;
105 			info->var.blue.length = info->var.bits_per_pixel / 3;
106 			info->var.blue.msb_right = 0;
107 		}
108 
109 		info->fix.visual = FB_VISUAL_TRUECOLOR;
110 		info->fix.line_length = info->var.bits_per_pixel > 16 ?
111 					info->var.xres_virtual << 2 :
112 					info->var.xres_virtual << 1;
113 	}
114 
115 	for (i = 0; i < 8; i++) {
116 		if (bpp_values[i] == info->var.bits_per_pixel) {
117 			reg_bpp = i;
118 			continue;
119 		}
120 	}
121 
122 	control0 = readl(fbi->regbase) & ~0xf;
123 	writel(0, fbi->regbase);
124 	while (readl(fbi->regbase + 0x38) & 0x10)
125 		/* wait */;
126 	writel((((info->var.hsync_len - 1) & 0x3f) << 26)
127 		| ((info->var.left_margin & 0xff) << 18)
128 		| (((info->var.xres - 1) & 0x3ff) << 8)
129 		| (info->var.right_margin & 0xff), fbi->regbase + 0x4);
130 	writel((((info->var.vsync_len - 1) & 0x3f) << 26)
131 		| ((info->var.upper_margin & 0xff) << 18)
132 		| (((info->var.yres - 1) & 0x3ff) << 8)
133 		| (info->var.lower_margin & 0xff), fbi->regbase + 0x8);
134 	writel((((info->var.yres - 1) & 0x400) << 2)
135 		| ((info->var.xres - 1) & 0x400), fbi->regbase + 0x10);
136 	writel(0x80000000, fbi->regbase + 0x20);
137 	writel(control0 | (reg_bpp << 1) | 0x100, fbi->regbase);
138 
139 	return 0;
140 }
141 
142 static inline u_int chan_to_field(u_int chan, struct fb_bitfield *bf)
143 {
144 	chan &= 0xffff;
145 	chan >>= 16 - bf->length;
146 	return chan << bf->offset;
147 }
148 
149 static int vt8500lcd_setcolreg(unsigned regno, unsigned red, unsigned green,
150 			   unsigned blue, unsigned transp,
151 			   struct fb_info *info) {
152 	struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
153 	int ret = 1;
154 	unsigned int val;
155 	if (regno >= 256)
156 		return -EINVAL;
157 
158 	if (info->var.grayscale)
159 		red = green = blue =
160 			(19595 * red + 38470 * green + 7471 * blue) >> 16;
161 
162 	switch (fbi->fb.fix.visual) {
163 	case FB_VISUAL_TRUECOLOR:
164 		if (regno < 16) {
165 			u32 *pal = fbi->fb.pseudo_palette;
166 
167 			val  = chan_to_field(red, &fbi->fb.var.red);
168 			val |= chan_to_field(green, &fbi->fb.var.green);
169 			val |= chan_to_field(blue, &fbi->fb.var.blue);
170 
171 			pal[regno] = val;
172 			ret = 0;
173 		}
174 		break;
175 
176 	case FB_VISUAL_STATIC_PSEUDOCOLOR:
177 	case FB_VISUAL_PSEUDOCOLOR:
178 		writew((red & 0xf800)
179 		      | ((green >> 5) & 0x7e0)
180 		      | ((blue >> 11) & 0x1f),
181 		       fbi->palette_cpu + sizeof(u16) * regno);
182 		break;
183 	}
184 
185 	return ret;
186 }
187 
188 static int vt8500lcd_ioctl(struct fb_info *info, unsigned int cmd,
189 			 unsigned long arg)
190 {
191 	int ret = 0;
192 	struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
193 
194 	if (cmd == FBIO_WAITFORVSYNC) {
195 		/* Unmask End of Frame interrupt */
196 		writel(0xffffffff ^ (1 << 3), fbi->regbase + 0x3c);
197 		ret = wait_event_interruptible_timeout(fbi->wait,
198 			readl(fbi->regbase + 0x38) & (1 << 3), HZ / 10);
199 		/* Mask back to reduce unwanted interrupt traffic */
200 		writel(0xffffffff, fbi->regbase + 0x3c);
201 		if (ret < 0)
202 			return ret;
203 		if (ret == 0)
204 			return -ETIMEDOUT;
205 	}
206 
207 	return ret;
208 }
209 
210 static int vt8500lcd_pan_display(struct fb_var_screeninfo *var,
211 				struct fb_info *info)
212 {
213 	unsigned pixlen = info->fix.line_length / info->var.xres_virtual;
214 	unsigned off = pixlen * var->xoffset
215 		      + info->fix.line_length * var->yoffset;
216 	struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
217 
218 	writel((1 << 31)
219 	     | (((info->var.xres_virtual - info->var.xres) * pixlen / 4) << 20)
220 	     | (off >> 2), fbi->regbase + 0x20);
221 	return 0;
222 }
223 
224 /*
225  * vt8500lcd_blank():
226  *	Blank the display by setting all palette values to zero.  Note,
227  * 	True Color modes do not really use the palette, so this will not
228  *      blank the display in all modes.
229  */
230 static int vt8500lcd_blank(int blank, struct fb_info *info)
231 {
232 	int i;
233 
234 	switch (blank) {
235 	case FB_BLANK_POWERDOWN:
236 	case FB_BLANK_VSYNC_SUSPEND:
237 	case FB_BLANK_HSYNC_SUSPEND:
238 	case FB_BLANK_NORMAL:
239 		if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR ||
240 		    info->fix.visual == FB_VISUAL_STATIC_PSEUDOCOLOR)
241 			for (i = 0; i < 256; i++)
242 				vt8500lcd_setcolreg(i, 0, 0, 0, 0, info);
243 	case FB_BLANK_UNBLANK:
244 		if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR ||
245 		    info->fix.visual == FB_VISUAL_STATIC_PSEUDOCOLOR)
246 			fb_set_cmap(&info->cmap, info);
247 	}
248 	return 0;
249 }
250 
251 static struct fb_ops vt8500lcd_ops = {
252 	.owner		= THIS_MODULE,
253 	.fb_set_par	= vt8500lcd_set_par,
254 	.fb_setcolreg	= vt8500lcd_setcolreg,
255 	.fb_fillrect	= wmt_ge_fillrect,
256 	.fb_copyarea	= wmt_ge_copyarea,
257 	.fb_imageblit	= sys_imageblit,
258 	.fb_sync	= wmt_ge_sync,
259 	.fb_ioctl	= vt8500lcd_ioctl,
260 	.fb_pan_display	= vt8500lcd_pan_display,
261 	.fb_blank	= vt8500lcd_blank,
262 };
263 
264 static irqreturn_t vt8500lcd_handle_irq(int irq, void *dev_id)
265 {
266 	struct vt8500lcd_info *fbi = dev_id;
267 
268 	if (readl(fbi->regbase + 0x38) & (1 << 3))
269 		wake_up_interruptible(&fbi->wait);
270 
271 	writel(0xffffffff, fbi->regbase + 0x38);
272 	return IRQ_HANDLED;
273 }
274 
275 static int vt8500lcd_probe(struct platform_device *pdev)
276 {
277 	struct vt8500lcd_info *fbi;
278 	struct resource *res;
279 	struct display_timings *disp_timing;
280 	void *addr;
281 	int irq, ret;
282 
283 	struct fb_videomode	of_mode;
284 	u32			bpp;
285 	dma_addr_t fb_mem_phys;
286 	unsigned long fb_mem_len;
287 	void *fb_mem_virt;
288 
289 	ret = -ENOMEM;
290 	fbi = NULL;
291 
292 	fbi = devm_kzalloc(&pdev->dev, sizeof(struct vt8500lcd_info)
293 			+ sizeof(u32) * 16, GFP_KERNEL);
294 	if (!fbi) {
295 		dev_err(&pdev->dev, "Failed to initialize framebuffer device\n");
296 		return -ENOMEM;
297 	}
298 
299 	strcpy(fbi->fb.fix.id, "VT8500 LCD");
300 
301 	fbi->fb.fix.type	= FB_TYPE_PACKED_PIXELS;
302 	fbi->fb.fix.xpanstep	= 0;
303 	fbi->fb.fix.ypanstep	= 1;
304 	fbi->fb.fix.ywrapstep	= 0;
305 	fbi->fb.fix.accel	= FB_ACCEL_NONE;
306 
307 	fbi->fb.var.nonstd	= 0;
308 	fbi->fb.var.activate	= FB_ACTIVATE_NOW;
309 	fbi->fb.var.height	= -1;
310 	fbi->fb.var.width	= -1;
311 	fbi->fb.var.vmode	= FB_VMODE_NONINTERLACED;
312 
313 	fbi->fb.fbops		= &vt8500lcd_ops;
314 	fbi->fb.flags		= FBINFO_DEFAULT
315 				| FBINFO_HWACCEL_COPYAREA
316 				| FBINFO_HWACCEL_FILLRECT
317 				| FBINFO_HWACCEL_YPAN
318 				| FBINFO_VIRTFB
319 				| FBINFO_PARTIAL_PAN_OK;
320 	fbi->fb.node		= -1;
321 
322 	addr = fbi;
323 	addr = addr + sizeof(struct vt8500lcd_info);
324 	fbi->fb.pseudo_palette	= addr;
325 
326 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
327 	if (res == NULL) {
328 		dev_err(&pdev->dev, "no I/O memory resource defined\n");
329 		return -ENODEV;
330 	}
331 
332 	res = request_mem_region(res->start, resource_size(res), "vt8500lcd");
333 	if (res == NULL) {
334 		dev_err(&pdev->dev, "failed to request I/O memory\n");
335 		return -EBUSY;
336 	}
337 
338 	fbi->regbase = ioremap(res->start, resource_size(res));
339 	if (fbi->regbase == NULL) {
340 		dev_err(&pdev->dev, "failed to map I/O memory\n");
341 		ret = -EBUSY;
342 		goto failed_free_res;
343 	}
344 
345 	disp_timing = of_get_display_timings(pdev->dev.of_node);
346 	if (!disp_timing) {
347 		ret = -EINVAL;
348 		goto failed_free_io;
349 	}
350 
351 	ret = of_get_fb_videomode(pdev->dev.of_node, &of_mode,
352 							OF_USE_NATIVE_MODE);
353 	if (ret)
354 		goto failed_free_io;
355 
356 	ret = of_property_read_u32(pdev->dev.of_node, "bits-per-pixel", &bpp);
357 	if (ret)
358 		goto failed_free_io;
359 
360 	/* try allocating the framebuffer */
361 	fb_mem_len = of_mode.xres * of_mode.yres * 2 * (bpp / 8);
362 	fb_mem_virt = dma_alloc_coherent(&pdev->dev, fb_mem_len, &fb_mem_phys,
363 				GFP_KERNEL);
364 	if (!fb_mem_virt) {
365 		pr_err("%s: Failed to allocate framebuffer\n", __func__);
366 		ret = -ENOMEM;
367 		goto failed_free_io;
368 	}
369 
370 	fbi->fb.fix.smem_start	= fb_mem_phys;
371 	fbi->fb.fix.smem_len	= fb_mem_len;
372 	fbi->fb.screen_base	= fb_mem_virt;
373 
374 	fbi->palette_size	= PAGE_ALIGN(512);
375 	fbi->palette_cpu	= dma_alloc_coherent(&pdev->dev,
376 						     fbi->palette_size,
377 						     &fbi->palette_phys,
378 						     GFP_KERNEL);
379 	if (fbi->palette_cpu == NULL) {
380 		dev_err(&pdev->dev, "Failed to allocate palette buffer\n");
381 		ret = -ENOMEM;
382 		goto failed_free_io;
383 	}
384 
385 	irq = platform_get_irq(pdev, 0);
386 	if (irq < 0) {
387 		dev_err(&pdev->dev, "no IRQ defined\n");
388 		ret = -ENODEV;
389 		goto failed_free_palette;
390 	}
391 
392 	ret = request_irq(irq, vt8500lcd_handle_irq, 0, "LCD", fbi);
393 	if (ret) {
394 		dev_err(&pdev->dev, "request_irq failed: %d\n", ret);
395 		ret = -EBUSY;
396 		goto failed_free_palette;
397 	}
398 
399 	init_waitqueue_head(&fbi->wait);
400 
401 	if (fb_alloc_cmap(&fbi->fb.cmap, 256, 0) < 0) {
402 		dev_err(&pdev->dev, "Failed to allocate color map\n");
403 		ret = -ENOMEM;
404 		goto failed_free_irq;
405 	}
406 
407 	fb_videomode_to_var(&fbi->fb.var, &of_mode);
408 
409 	fbi->fb.var.xres_virtual	= of_mode.xres;
410 	fbi->fb.var.yres_virtual	= of_mode.yres * 2;
411 	fbi->fb.var.bits_per_pixel	= bpp;
412 
413 	ret = vt8500lcd_set_par(&fbi->fb);
414 	if (ret) {
415 		dev_err(&pdev->dev, "Failed to set parameters\n");
416 		goto failed_free_cmap;
417 	}
418 
419 	writel(fbi->fb.fix.smem_start >> 22, fbi->regbase + 0x1c);
420 	writel((fbi->palette_phys & 0xfffffe00) | 1, fbi->regbase + 0x18);
421 
422 	platform_set_drvdata(pdev, fbi);
423 
424 	ret = register_framebuffer(&fbi->fb);
425 	if (ret < 0) {
426 		dev_err(&pdev->dev,
427 			"Failed to register framebuffer device: %d\n", ret);
428 		goto failed_free_cmap;
429 	}
430 
431 	/*
432 	 * Ok, now enable the LCD controller
433 	 */
434 	writel(readl(fbi->regbase) | 1, fbi->regbase);
435 
436 	return 0;
437 
438 failed_free_cmap:
439 	if (fbi->fb.cmap.len)
440 		fb_dealloc_cmap(&fbi->fb.cmap);
441 failed_free_irq:
442 	free_irq(irq, fbi);
443 failed_free_palette:
444 	dma_free_coherent(&pdev->dev, fbi->palette_size,
445 			  fbi->palette_cpu, fbi->palette_phys);
446 failed_free_io:
447 	iounmap(fbi->regbase);
448 failed_free_res:
449 	release_mem_region(res->start, resource_size(res));
450 	return ret;
451 }
452 
453 static int vt8500lcd_remove(struct platform_device *pdev)
454 {
455 	struct vt8500lcd_info *fbi = platform_get_drvdata(pdev);
456 	struct resource *res;
457 	int irq;
458 
459 	unregister_framebuffer(&fbi->fb);
460 
461 	writel(0, fbi->regbase);
462 
463 	if (fbi->fb.cmap.len)
464 		fb_dealloc_cmap(&fbi->fb.cmap);
465 
466 	irq = platform_get_irq(pdev, 0);
467 	free_irq(irq, fbi);
468 
469 	dma_free_coherent(&pdev->dev, fbi->palette_size,
470 			  fbi->palette_cpu, fbi->palette_phys);
471 
472 	iounmap(fbi->regbase);
473 
474 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
475 	release_mem_region(res->start, resource_size(res));
476 
477 	kfree(fbi);
478 
479 	return 0;
480 }
481 
482 static const struct of_device_id via_dt_ids[] = {
483 	{ .compatible = "via,vt8500-fb", },
484 	{}
485 };
486 
487 static struct platform_driver vt8500lcd_driver = {
488 	.probe		= vt8500lcd_probe,
489 	.remove		= vt8500lcd_remove,
490 	.driver		= {
491 		.owner	= THIS_MODULE,
492 		.name	= "vt8500-lcd",
493 		.of_match_table = of_match_ptr(via_dt_ids),
494 	},
495 };
496 
497 module_platform_driver(vt8500lcd_driver);
498 
499 MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
500 MODULE_DESCRIPTION("LCD controller driver for VIA VT8500");
501 MODULE_LICENSE("GPL v2");
502 MODULE_DEVICE_TABLE(of, via_dt_ids);
503