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 	}
119 
120 	control0 = readl(fbi->regbase) & ~0xf;
121 	writel(0, fbi->regbase);
122 	while (readl(fbi->regbase + 0x38) & 0x10)
123 		/* wait */;
124 	writel((((info->var.hsync_len - 1) & 0x3f) << 26)
125 		| ((info->var.left_margin & 0xff) << 18)
126 		| (((info->var.xres - 1) & 0x3ff) << 8)
127 		| (info->var.right_margin & 0xff), fbi->regbase + 0x4);
128 	writel((((info->var.vsync_len - 1) & 0x3f) << 26)
129 		| ((info->var.upper_margin & 0xff) << 18)
130 		| (((info->var.yres - 1) & 0x3ff) << 8)
131 		| (info->var.lower_margin & 0xff), fbi->regbase + 0x8);
132 	writel((((info->var.yres - 1) & 0x400) << 2)
133 		| ((info->var.xres - 1) & 0x400), fbi->regbase + 0x10);
134 	writel(0x80000000, fbi->regbase + 0x20);
135 	writel(control0 | (reg_bpp << 1) | 0x100, fbi->regbase);
136 
137 	return 0;
138 }
139 
140 static inline u_int chan_to_field(u_int chan, struct fb_bitfield *bf)
141 {
142 	chan &= 0xffff;
143 	chan >>= 16 - bf->length;
144 	return chan << bf->offset;
145 }
146 
147 static int vt8500lcd_setcolreg(unsigned regno, unsigned red, unsigned green,
148 			   unsigned blue, unsigned transp,
149 			   struct fb_info *info) {
150 	struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
151 	int ret = 1;
152 	unsigned int val;
153 	if (regno >= 256)
154 		return -EINVAL;
155 
156 	if (info->var.grayscale)
157 		red = green = blue =
158 			(19595 * red + 38470 * green + 7471 * blue) >> 16;
159 
160 	switch (fbi->fb.fix.visual) {
161 	case FB_VISUAL_TRUECOLOR:
162 		if (regno < 16) {
163 			u32 *pal = fbi->fb.pseudo_palette;
164 
165 			val  = chan_to_field(red, &fbi->fb.var.red);
166 			val |= chan_to_field(green, &fbi->fb.var.green);
167 			val |= chan_to_field(blue, &fbi->fb.var.blue);
168 
169 			pal[regno] = val;
170 			ret = 0;
171 		}
172 		break;
173 
174 	case FB_VISUAL_STATIC_PSEUDOCOLOR:
175 	case FB_VISUAL_PSEUDOCOLOR:
176 		writew((red & 0xf800)
177 		      | ((green >> 5) & 0x7e0)
178 		      | ((blue >> 11) & 0x1f),
179 		       fbi->palette_cpu + sizeof(u16) * regno);
180 		break;
181 	}
182 
183 	return ret;
184 }
185 
186 static int vt8500lcd_ioctl(struct fb_info *info, unsigned int cmd,
187 			 unsigned long arg)
188 {
189 	int ret = 0;
190 	struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
191 
192 	if (cmd == FBIO_WAITFORVSYNC) {
193 		/* Unmask End of Frame interrupt */
194 		writel(0xffffffff ^ (1 << 3), fbi->regbase + 0x3c);
195 		ret = wait_event_interruptible_timeout(fbi->wait,
196 			readl(fbi->regbase + 0x38) & (1 << 3), HZ / 10);
197 		/* Mask back to reduce unwanted interrupt traffic */
198 		writel(0xffffffff, fbi->regbase + 0x3c);
199 		if (ret < 0)
200 			return ret;
201 		if (ret == 0)
202 			return -ETIMEDOUT;
203 	}
204 
205 	return ret;
206 }
207 
208 static int vt8500lcd_pan_display(struct fb_var_screeninfo *var,
209 				struct fb_info *info)
210 {
211 	unsigned pixlen = info->fix.line_length / info->var.xres_virtual;
212 	unsigned off = pixlen * var->xoffset
213 		      + info->fix.line_length * var->yoffset;
214 	struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
215 
216 	writel((1 << 31)
217 	     | (((info->var.xres_virtual - info->var.xres) * pixlen / 4) << 20)
218 	     | (off >> 2), fbi->regbase + 0x20);
219 	return 0;
220 }
221 
222 /*
223  * vt8500lcd_blank():
224  *	Blank the display by setting all palette values to zero.  Note,
225  * 	True Color modes do not really use the palette, so this will not
226  *      blank the display in all modes.
227  */
228 static int vt8500lcd_blank(int blank, struct fb_info *info)
229 {
230 	int i;
231 
232 	switch (blank) {
233 	case FB_BLANK_POWERDOWN:
234 	case FB_BLANK_VSYNC_SUSPEND:
235 	case FB_BLANK_HSYNC_SUSPEND:
236 	case FB_BLANK_NORMAL:
237 		if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR ||
238 		    info->fix.visual == FB_VISUAL_STATIC_PSEUDOCOLOR)
239 			for (i = 0; i < 256; i++)
240 				vt8500lcd_setcolreg(i, 0, 0, 0, 0, info);
241 	case FB_BLANK_UNBLANK:
242 		if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR ||
243 		    info->fix.visual == FB_VISUAL_STATIC_PSEUDOCOLOR)
244 			fb_set_cmap(&info->cmap, info);
245 	}
246 	return 0;
247 }
248 
249 static struct fb_ops vt8500lcd_ops = {
250 	.owner		= THIS_MODULE,
251 	.fb_set_par	= vt8500lcd_set_par,
252 	.fb_setcolreg	= vt8500lcd_setcolreg,
253 	.fb_fillrect	= wmt_ge_fillrect,
254 	.fb_copyarea	= wmt_ge_copyarea,
255 	.fb_imageblit	= sys_imageblit,
256 	.fb_sync	= wmt_ge_sync,
257 	.fb_ioctl	= vt8500lcd_ioctl,
258 	.fb_pan_display	= vt8500lcd_pan_display,
259 	.fb_blank	= vt8500lcd_blank,
260 };
261 
262 static irqreturn_t vt8500lcd_handle_irq(int irq, void *dev_id)
263 {
264 	struct vt8500lcd_info *fbi = dev_id;
265 
266 	if (readl(fbi->regbase + 0x38) & (1 << 3))
267 		wake_up_interruptible(&fbi->wait);
268 
269 	writel(0xffffffff, fbi->regbase + 0x38);
270 	return IRQ_HANDLED;
271 }
272 
273 static int vt8500lcd_probe(struct platform_device *pdev)
274 {
275 	struct vt8500lcd_info *fbi;
276 	struct resource *res;
277 	struct display_timings *disp_timing;
278 	void *addr;
279 	int irq, ret;
280 
281 	struct fb_videomode	of_mode;
282 	u32			bpp;
283 	dma_addr_t fb_mem_phys;
284 	unsigned long fb_mem_len;
285 	void *fb_mem_virt;
286 
287 	ret = -ENOMEM;
288 	fbi = NULL;
289 
290 	fbi = devm_kzalloc(&pdev->dev, sizeof(struct vt8500lcd_info)
291 			+ sizeof(u32) * 16, GFP_KERNEL);
292 	if (!fbi)
293 		return -ENOMEM;
294 
295 	strcpy(fbi->fb.fix.id, "VT8500 LCD");
296 
297 	fbi->fb.fix.type	= FB_TYPE_PACKED_PIXELS;
298 	fbi->fb.fix.xpanstep	= 0;
299 	fbi->fb.fix.ypanstep	= 1;
300 	fbi->fb.fix.ywrapstep	= 0;
301 	fbi->fb.fix.accel	= FB_ACCEL_NONE;
302 
303 	fbi->fb.var.nonstd	= 0;
304 	fbi->fb.var.activate	= FB_ACTIVATE_NOW;
305 	fbi->fb.var.height	= -1;
306 	fbi->fb.var.width	= -1;
307 	fbi->fb.var.vmode	= FB_VMODE_NONINTERLACED;
308 
309 	fbi->fb.fbops		= &vt8500lcd_ops;
310 	fbi->fb.flags		= FBINFO_DEFAULT
311 				| FBINFO_HWACCEL_COPYAREA
312 				| FBINFO_HWACCEL_FILLRECT
313 				| FBINFO_HWACCEL_YPAN
314 				| FBINFO_VIRTFB
315 				| FBINFO_PARTIAL_PAN_OK;
316 	fbi->fb.node		= -1;
317 
318 	addr = fbi;
319 	addr = addr + sizeof(struct vt8500lcd_info);
320 	fbi->fb.pseudo_palette	= addr;
321 
322 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
323 	if (res == NULL) {
324 		dev_err(&pdev->dev, "no I/O memory resource defined\n");
325 		return -ENODEV;
326 	}
327 
328 	res = request_mem_region(res->start, resource_size(res), "vt8500lcd");
329 	if (res == NULL) {
330 		dev_err(&pdev->dev, "failed to request I/O memory\n");
331 		return -EBUSY;
332 	}
333 
334 	fbi->regbase = ioremap(res->start, resource_size(res));
335 	if (fbi->regbase == NULL) {
336 		dev_err(&pdev->dev, "failed to map I/O memory\n");
337 		ret = -EBUSY;
338 		goto failed_free_res;
339 	}
340 
341 	disp_timing = of_get_display_timings(pdev->dev.of_node);
342 	if (!disp_timing) {
343 		ret = -EINVAL;
344 		goto failed_free_io;
345 	}
346 
347 	ret = of_get_fb_videomode(pdev->dev.of_node, &of_mode,
348 							OF_USE_NATIVE_MODE);
349 	if (ret)
350 		goto failed_free_io;
351 
352 	ret = of_property_read_u32(pdev->dev.of_node, "bits-per-pixel", &bpp);
353 	if (ret)
354 		goto failed_free_io;
355 
356 	/* try allocating the framebuffer */
357 	fb_mem_len = of_mode.xres * of_mode.yres * 2 * (bpp / 8);
358 	fb_mem_virt = dma_alloc_coherent(&pdev->dev, fb_mem_len, &fb_mem_phys,
359 				GFP_KERNEL);
360 	if (!fb_mem_virt) {
361 		pr_err("%s: Failed to allocate framebuffer\n", __func__);
362 		ret = -ENOMEM;
363 		goto failed_free_io;
364 	}
365 
366 	fbi->fb.fix.smem_start	= fb_mem_phys;
367 	fbi->fb.fix.smem_len	= fb_mem_len;
368 	fbi->fb.screen_base	= fb_mem_virt;
369 
370 	fbi->palette_size	= PAGE_ALIGN(512);
371 	fbi->palette_cpu	= dma_alloc_coherent(&pdev->dev,
372 						     fbi->palette_size,
373 						     &fbi->palette_phys,
374 						     GFP_KERNEL);
375 	if (fbi->palette_cpu == NULL) {
376 		dev_err(&pdev->dev, "Failed to allocate palette buffer\n");
377 		ret = -ENOMEM;
378 		goto failed_free_io;
379 	}
380 
381 	irq = platform_get_irq(pdev, 0);
382 	if (irq < 0) {
383 		dev_err(&pdev->dev, "no IRQ defined\n");
384 		ret = -ENODEV;
385 		goto failed_free_palette;
386 	}
387 
388 	ret = request_irq(irq, vt8500lcd_handle_irq, 0, "LCD", fbi);
389 	if (ret) {
390 		dev_err(&pdev->dev, "request_irq failed: %d\n", ret);
391 		ret = -EBUSY;
392 		goto failed_free_palette;
393 	}
394 
395 	init_waitqueue_head(&fbi->wait);
396 
397 	if (fb_alloc_cmap(&fbi->fb.cmap, 256, 0) < 0) {
398 		dev_err(&pdev->dev, "Failed to allocate color map\n");
399 		ret = -ENOMEM;
400 		goto failed_free_irq;
401 	}
402 
403 	fb_videomode_to_var(&fbi->fb.var, &of_mode);
404 
405 	fbi->fb.var.xres_virtual	= of_mode.xres;
406 	fbi->fb.var.yres_virtual	= of_mode.yres * 2;
407 	fbi->fb.var.bits_per_pixel	= bpp;
408 
409 	ret = vt8500lcd_set_par(&fbi->fb);
410 	if (ret) {
411 		dev_err(&pdev->dev, "Failed to set parameters\n");
412 		goto failed_free_cmap;
413 	}
414 
415 	writel(fbi->fb.fix.smem_start >> 22, fbi->regbase + 0x1c);
416 	writel((fbi->palette_phys & 0xfffffe00) | 1, fbi->regbase + 0x18);
417 
418 	platform_set_drvdata(pdev, fbi);
419 
420 	ret = register_framebuffer(&fbi->fb);
421 	if (ret < 0) {
422 		dev_err(&pdev->dev,
423 			"Failed to register framebuffer device: %d\n", ret);
424 		goto failed_free_cmap;
425 	}
426 
427 	/*
428 	 * Ok, now enable the LCD controller
429 	 */
430 	writel(readl(fbi->regbase) | 1, fbi->regbase);
431 
432 	return 0;
433 
434 failed_free_cmap:
435 	if (fbi->fb.cmap.len)
436 		fb_dealloc_cmap(&fbi->fb.cmap);
437 failed_free_irq:
438 	free_irq(irq, fbi);
439 failed_free_palette:
440 	dma_free_coherent(&pdev->dev, fbi->palette_size,
441 			  fbi->palette_cpu, fbi->palette_phys);
442 failed_free_io:
443 	iounmap(fbi->regbase);
444 failed_free_res:
445 	release_mem_region(res->start, resource_size(res));
446 	return ret;
447 }
448 
449 static int vt8500lcd_remove(struct platform_device *pdev)
450 {
451 	struct vt8500lcd_info *fbi = platform_get_drvdata(pdev);
452 	struct resource *res;
453 	int irq;
454 
455 	unregister_framebuffer(&fbi->fb);
456 
457 	writel(0, fbi->regbase);
458 
459 	if (fbi->fb.cmap.len)
460 		fb_dealloc_cmap(&fbi->fb.cmap);
461 
462 	irq = platform_get_irq(pdev, 0);
463 	free_irq(irq, fbi);
464 
465 	dma_free_coherent(&pdev->dev, fbi->palette_size,
466 			  fbi->palette_cpu, fbi->palette_phys);
467 
468 	iounmap(fbi->regbase);
469 
470 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
471 	release_mem_region(res->start, resource_size(res));
472 
473 	return 0;
474 }
475 
476 static const struct of_device_id via_dt_ids[] = {
477 	{ .compatible = "via,vt8500-fb", },
478 	{}
479 };
480 
481 static struct platform_driver vt8500lcd_driver = {
482 	.probe		= vt8500lcd_probe,
483 	.remove		= vt8500lcd_remove,
484 	.driver		= {
485 		.name	= "vt8500-lcd",
486 		.of_match_table = of_match_ptr(via_dt_ids),
487 	},
488 };
489 
490 module_platform_driver(vt8500lcd_driver);
491 
492 MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
493 MODULE_DESCRIPTION("LCD controller driver for VIA VT8500");
494 MODULE_LICENSE("GPL v2");
495 MODULE_DEVICE_TABLE(of, via_dt_ids);
496