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
47static 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
140static 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
147static 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
186static 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
208static 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 */
228static 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
249static 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
262static 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
273static 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		dev_err(&pdev->dev, "Failed to initialize framebuffer device\n");
294		return -ENOMEM;
295	}
296
297	strcpy(fbi->fb.fix.id, "VT8500 LCD");
298
299	fbi->fb.fix.type	= FB_TYPE_PACKED_PIXELS;
300	fbi->fb.fix.xpanstep	= 0;
301	fbi->fb.fix.ypanstep	= 1;
302	fbi->fb.fix.ywrapstep	= 0;
303	fbi->fb.fix.accel	= FB_ACCEL_NONE;
304
305	fbi->fb.var.nonstd	= 0;
306	fbi->fb.var.activate	= FB_ACTIVATE_NOW;
307	fbi->fb.var.height	= -1;
308	fbi->fb.var.width	= -1;
309	fbi->fb.var.vmode	= FB_VMODE_NONINTERLACED;
310
311	fbi->fb.fbops		= &vt8500lcd_ops;
312	fbi->fb.flags		= FBINFO_DEFAULT
313				| FBINFO_HWACCEL_COPYAREA
314				| FBINFO_HWACCEL_FILLRECT
315				| FBINFO_HWACCEL_YPAN
316				| FBINFO_VIRTFB
317				| FBINFO_PARTIAL_PAN_OK;
318	fbi->fb.node		= -1;
319
320	addr = fbi;
321	addr = addr + sizeof(struct vt8500lcd_info);
322	fbi->fb.pseudo_palette	= addr;
323
324	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
325	if (res == NULL) {
326		dev_err(&pdev->dev, "no I/O memory resource defined\n");
327		return -ENODEV;
328	}
329
330	res = request_mem_region(res->start, resource_size(res), "vt8500lcd");
331	if (res == NULL) {
332		dev_err(&pdev->dev, "failed to request I/O memory\n");
333		return -EBUSY;
334	}
335
336	fbi->regbase = ioremap(res->start, resource_size(res));
337	if (fbi->regbase == NULL) {
338		dev_err(&pdev->dev, "failed to map I/O memory\n");
339		ret = -EBUSY;
340		goto failed_free_res;
341	}
342
343	disp_timing = of_get_display_timings(pdev->dev.of_node);
344	if (!disp_timing) {
345		ret = -EINVAL;
346		goto failed_free_io;
347	}
348
349	ret = of_get_fb_videomode(pdev->dev.of_node, &of_mode,
350							OF_USE_NATIVE_MODE);
351	if (ret)
352		goto failed_free_io;
353
354	ret = of_property_read_u32(pdev->dev.of_node, "bits-per-pixel", &bpp);
355	if (ret)
356		goto failed_free_io;
357
358	/* try allocating the framebuffer */
359	fb_mem_len = of_mode.xres * of_mode.yres * 2 * (bpp / 8);
360	fb_mem_virt = dma_alloc_coherent(&pdev->dev, fb_mem_len, &fb_mem_phys,
361				GFP_KERNEL);
362	if (!fb_mem_virt) {
363		pr_err("%s: Failed to allocate framebuffer\n", __func__);
364		ret = -ENOMEM;
365		goto failed_free_io;
366	}
367
368	fbi->fb.fix.smem_start	= fb_mem_phys;
369	fbi->fb.fix.smem_len	= fb_mem_len;
370	fbi->fb.screen_base	= fb_mem_virt;
371
372	fbi->palette_size	= PAGE_ALIGN(512);
373	fbi->palette_cpu	= dma_alloc_coherent(&pdev->dev,
374						     fbi->palette_size,
375						     &fbi->palette_phys,
376						     GFP_KERNEL);
377	if (fbi->palette_cpu == NULL) {
378		dev_err(&pdev->dev, "Failed to allocate palette buffer\n");
379		ret = -ENOMEM;
380		goto failed_free_io;
381	}
382
383	irq = platform_get_irq(pdev, 0);
384	if (irq < 0) {
385		dev_err(&pdev->dev, "no IRQ defined\n");
386		ret = -ENODEV;
387		goto failed_free_palette;
388	}
389
390	ret = request_irq(irq, vt8500lcd_handle_irq, 0, "LCD", fbi);
391	if (ret) {
392		dev_err(&pdev->dev, "request_irq failed: %d\n", ret);
393		ret = -EBUSY;
394		goto failed_free_palette;
395	}
396
397	init_waitqueue_head(&fbi->wait);
398
399	if (fb_alloc_cmap(&fbi->fb.cmap, 256, 0) < 0) {
400		dev_err(&pdev->dev, "Failed to allocate color map\n");
401		ret = -ENOMEM;
402		goto failed_free_irq;
403	}
404
405	fb_videomode_to_var(&fbi->fb.var, &of_mode);
406
407	fbi->fb.var.xres_virtual	= of_mode.xres;
408	fbi->fb.var.yres_virtual	= of_mode.yres * 2;
409	fbi->fb.var.bits_per_pixel	= bpp;
410
411	ret = vt8500lcd_set_par(&fbi->fb);
412	if (ret) {
413		dev_err(&pdev->dev, "Failed to set parameters\n");
414		goto failed_free_cmap;
415	}
416
417	writel(fbi->fb.fix.smem_start >> 22, fbi->regbase + 0x1c);
418	writel((fbi->palette_phys & 0xfffffe00) | 1, fbi->regbase + 0x18);
419
420	platform_set_drvdata(pdev, fbi);
421
422	ret = register_framebuffer(&fbi->fb);
423	if (ret < 0) {
424		dev_err(&pdev->dev,
425			"Failed to register framebuffer device: %d\n", ret);
426		goto failed_free_cmap;
427	}
428
429	/*
430	 * Ok, now enable the LCD controller
431	 */
432	writel(readl(fbi->regbase) | 1, fbi->regbase);
433
434	return 0;
435
436failed_free_cmap:
437	if (fbi->fb.cmap.len)
438		fb_dealloc_cmap(&fbi->fb.cmap);
439failed_free_irq:
440	free_irq(irq, fbi);
441failed_free_palette:
442	dma_free_coherent(&pdev->dev, fbi->palette_size,
443			  fbi->palette_cpu, fbi->palette_phys);
444failed_free_io:
445	iounmap(fbi->regbase);
446failed_free_res:
447	release_mem_region(res->start, resource_size(res));
448	return ret;
449}
450
451static int vt8500lcd_remove(struct platform_device *pdev)
452{
453	struct vt8500lcd_info *fbi = platform_get_drvdata(pdev);
454	struct resource *res;
455	int irq;
456
457	unregister_framebuffer(&fbi->fb);
458
459	writel(0, fbi->regbase);
460
461	if (fbi->fb.cmap.len)
462		fb_dealloc_cmap(&fbi->fb.cmap);
463
464	irq = platform_get_irq(pdev, 0);
465	free_irq(irq, fbi);
466
467	dma_free_coherent(&pdev->dev, fbi->palette_size,
468			  fbi->palette_cpu, fbi->palette_phys);
469
470	iounmap(fbi->regbase);
471
472	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
473	release_mem_region(res->start, resource_size(res));
474
475	return 0;
476}
477
478static const struct of_device_id via_dt_ids[] = {
479	{ .compatible = "via,vt8500-fb", },
480	{}
481};
482
483static struct platform_driver vt8500lcd_driver = {
484	.probe		= vt8500lcd_probe,
485	.remove		= vt8500lcd_remove,
486	.driver		= {
487		.name	= "vt8500-lcd",
488		.of_match_table = of_match_ptr(via_dt_ids),
489	},
490};
491
492module_platform_driver(vt8500lcd_driver);
493
494MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
495MODULE_DESCRIPTION("LCD controller driver for VIA VT8500");
496MODULE_LICENSE("GPL v2");
497MODULE_DEVICE_TABLE(of, via_dt_ids);
498