1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *  linux/drivers/video/vt8500lcdfb.c
4 *
5 *  Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
6 *
7 * Based on skeletonfb.c and pxafb.c
8 */
9
10#include <linux/delay.h>
11#include <linux/dma-mapping.h>
12#include <linux/errno.h>
13#include <linux/fb.h>
14#include <linux/init.h>
15#include <linux/interrupt.h>
16#include <linux/io.h>
17#include <linux/kernel.h>
18#include <linux/mm.h>
19#include <linux/module.h>
20#include <linux/platform_device.h>
21#include <linux/slab.h>
22#include <linux/string.h>
23#include <linux/wait.h>
24#include <video/of_display_timing.h>
25
26#include "vt8500lcdfb.h"
27#include "wmt_ge_rops.h"
28
29#ifdef CONFIG_OF
30#include <linux/of.h>
31#include <linux/of_fdt.h>
32#include <linux/memblock.h>
33#endif
34
35
36#define to_vt8500lcd_info(__info) container_of(__info, \
37						struct vt8500lcd_info, fb)
38
39static int vt8500lcd_set_par(struct fb_info *info)
40{
41	struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
42	int reg_bpp = 5; /* 16bpp */
43	int i;
44	unsigned long control0;
45
46	if (!fbi)
47		return -EINVAL;
48
49	if (info->var.bits_per_pixel <= 8) {
50		/* palettized */
51		info->var.red.offset    = 0;
52		info->var.red.length    = info->var.bits_per_pixel;
53		info->var.red.msb_right = 0;
54
55		info->var.green.offset  = 0;
56		info->var.green.length  = info->var.bits_per_pixel;
57		info->var.green.msb_right = 0;
58
59		info->var.blue.offset   = 0;
60		info->var.blue.length   = info->var.bits_per_pixel;
61		info->var.blue.msb_right = 0;
62
63		info->var.transp.offset = 0;
64		info->var.transp.length = 0;
65		info->var.transp.msb_right = 0;
66
67		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
68		info->fix.line_length = info->var.xres_virtual /
69						(8/info->var.bits_per_pixel);
70	} else {
71		/* non-palettized */
72		info->var.transp.offset = 0;
73		info->var.transp.length = 0;
74		info->var.transp.msb_right = 0;
75
76		if (info->var.bits_per_pixel == 16) {
77			/* RGB565 */
78			info->var.red.offset = 11;
79			info->var.red.length = 5;
80			info->var.red.msb_right = 0;
81			info->var.green.offset = 5;
82			info->var.green.length = 6;
83			info->var.green.msb_right = 0;
84			info->var.blue.offset = 0;
85			info->var.blue.length = 5;
86			info->var.blue.msb_right = 0;
87		} else {
88			/* Equal depths per channel */
89			info->var.red.offset = info->var.bits_per_pixel
90							* 2 / 3;
91			info->var.red.length = info->var.bits_per_pixel / 3;
92			info->var.red.msb_right = 0;
93			info->var.green.offset = info->var.bits_per_pixel / 3;
94			info->var.green.length = info->var.bits_per_pixel / 3;
95			info->var.green.msb_right = 0;
96			info->var.blue.offset = 0;
97			info->var.blue.length = info->var.bits_per_pixel / 3;
98			info->var.blue.msb_right = 0;
99		}
100
101		info->fix.visual = FB_VISUAL_TRUECOLOR;
102		info->fix.line_length = info->var.bits_per_pixel > 16 ?
103					info->var.xres_virtual << 2 :
104					info->var.xres_virtual << 1;
105	}
106
107	for (i = 0; i < 8; i++) {
108		if (bpp_values[i] == info->var.bits_per_pixel)
109			reg_bpp = i;
110	}
111
112	control0 = readl(fbi->regbase) & ~0xf;
113	writel(0, fbi->regbase);
114	while (readl(fbi->regbase + 0x38) & 0x10)
115		/* wait */;
116	writel((((info->var.hsync_len - 1) & 0x3f) << 26)
117		| ((info->var.left_margin & 0xff) << 18)
118		| (((info->var.xres - 1) & 0x3ff) << 8)
119		| (info->var.right_margin & 0xff), fbi->regbase + 0x4);
120	writel((((info->var.vsync_len - 1) & 0x3f) << 26)
121		| ((info->var.upper_margin & 0xff) << 18)
122		| (((info->var.yres - 1) & 0x3ff) << 8)
123		| (info->var.lower_margin & 0xff), fbi->regbase + 0x8);
124	writel((((info->var.yres - 1) & 0x400) << 2)
125		| ((info->var.xres - 1) & 0x400), fbi->regbase + 0x10);
126	writel(0x80000000, fbi->regbase + 0x20);
127	writel(control0 | (reg_bpp << 1) | 0x100, fbi->regbase);
128
129	return 0;
130}
131
132static inline u_int chan_to_field(u_int chan, struct fb_bitfield *bf)
133{
134	chan &= 0xffff;
135	chan >>= 16 - bf->length;
136	return chan << bf->offset;
137}
138
139static int vt8500lcd_setcolreg(unsigned regno, unsigned red, unsigned green,
140			   unsigned blue, unsigned transp,
141			   struct fb_info *info) {
142	struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
143	int ret = 1;
144	unsigned int val;
145	if (regno >= 256)
146		return -EINVAL;
147
148	if (info->var.grayscale)
149		red = green = blue =
150			(19595 * red + 38470 * green + 7471 * blue) >> 16;
151
152	switch (fbi->fb.fix.visual) {
153	case FB_VISUAL_TRUECOLOR:
154		if (regno < 16) {
155			u32 *pal = fbi->fb.pseudo_palette;
156
157			val  = chan_to_field(red, &fbi->fb.var.red);
158			val |= chan_to_field(green, &fbi->fb.var.green);
159			val |= chan_to_field(blue, &fbi->fb.var.blue);
160
161			pal[regno] = val;
162			ret = 0;
163		}
164		break;
165
166	case FB_VISUAL_STATIC_PSEUDOCOLOR:
167	case FB_VISUAL_PSEUDOCOLOR:
168		writew((red & 0xf800)
169		      | ((green >> 5) & 0x7e0)
170		      | ((blue >> 11) & 0x1f),
171		       fbi->palette_cpu + sizeof(u16) * regno);
172		break;
173	}
174
175	return ret;
176}
177
178static int vt8500lcd_ioctl(struct fb_info *info, unsigned int cmd,
179			 unsigned long arg)
180{
181	int ret = 0;
182	struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
183
184	if (cmd == FBIO_WAITFORVSYNC) {
185		/* Unmask End of Frame interrupt */
186		writel(0xffffffff ^ (1 << 3), fbi->regbase + 0x3c);
187		ret = wait_event_interruptible_timeout(fbi->wait,
188			readl(fbi->regbase + 0x38) & (1 << 3), HZ / 10);
189		/* Mask back to reduce unwanted interrupt traffic */
190		writel(0xffffffff, fbi->regbase + 0x3c);
191		if (ret < 0)
192			return ret;
193		if (ret == 0)
194			return -ETIMEDOUT;
195	}
196
197	return ret;
198}
199
200static int vt8500lcd_pan_display(struct fb_var_screeninfo *var,
201				struct fb_info *info)
202{
203	unsigned pixlen = info->fix.line_length / info->var.xres_virtual;
204	unsigned off = pixlen * var->xoffset
205		      + info->fix.line_length * var->yoffset;
206	struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
207
208	writel((1 << 31)
209	     | (((info->var.xres_virtual - info->var.xres) * pixlen / 4) << 20)
210	     | (off >> 2), fbi->regbase + 0x20);
211	return 0;
212}
213
214/*
215 * vt8500lcd_blank():
216 *	Blank the display by setting all palette values to zero.  Note,
217 * 	True Color modes do not really use the palette, so this will not
218 *      blank the display in all modes.
219 */
220static int vt8500lcd_blank(int blank, struct fb_info *info)
221{
222	int i;
223
224	switch (blank) {
225	case FB_BLANK_POWERDOWN:
226	case FB_BLANK_VSYNC_SUSPEND:
227	case FB_BLANK_HSYNC_SUSPEND:
228	case FB_BLANK_NORMAL:
229		if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR ||
230		    info->fix.visual == FB_VISUAL_STATIC_PSEUDOCOLOR)
231			for (i = 0; i < 256; i++)
232				vt8500lcd_setcolreg(i, 0, 0, 0, 0, info);
233		fallthrough;
234	case FB_BLANK_UNBLANK:
235		if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR ||
236		    info->fix.visual == FB_VISUAL_STATIC_PSEUDOCOLOR)
237			fb_set_cmap(&info->cmap, info);
238	}
239	return 0;
240}
241
242static const struct fb_ops vt8500lcd_ops = {
243	.owner		= THIS_MODULE,
244	.fb_set_par	= vt8500lcd_set_par,
245	.fb_setcolreg	= vt8500lcd_setcolreg,
246	.fb_fillrect	= wmt_ge_fillrect,
247	.fb_copyarea	= wmt_ge_copyarea,
248	.fb_imageblit	= sys_imageblit,
249	.fb_sync	= wmt_ge_sync,
250	.fb_ioctl	= vt8500lcd_ioctl,
251	.fb_pan_display	= vt8500lcd_pan_display,
252	.fb_blank	= vt8500lcd_blank,
253};
254
255static irqreturn_t vt8500lcd_handle_irq(int irq, void *dev_id)
256{
257	struct vt8500lcd_info *fbi = dev_id;
258
259	if (readl(fbi->regbase + 0x38) & (1 << 3))
260		wake_up_interruptible(&fbi->wait);
261
262	writel(0xffffffff, fbi->regbase + 0x38);
263	return IRQ_HANDLED;
264}
265
266static int vt8500lcd_probe(struct platform_device *pdev)
267{
268	struct vt8500lcd_info *fbi;
269	struct resource *res;
270	struct display_timings *disp_timing;
271	void *addr;
272	int irq, ret;
273
274	struct fb_videomode	of_mode;
275	u32			bpp;
276	dma_addr_t fb_mem_phys;
277	unsigned long fb_mem_len;
278	void *fb_mem_virt;
279
280	ret = -ENOMEM;
281	fbi = NULL;
282
283	fbi = devm_kzalloc(&pdev->dev, sizeof(struct vt8500lcd_info)
284			+ sizeof(u32) * 16, GFP_KERNEL);
285	if (!fbi)
286		return -ENOMEM;
287
288	strcpy(fbi->fb.fix.id, "VT8500 LCD");
289
290	fbi->fb.fix.type	= FB_TYPE_PACKED_PIXELS;
291	fbi->fb.fix.xpanstep	= 0;
292	fbi->fb.fix.ypanstep	= 1;
293	fbi->fb.fix.ywrapstep	= 0;
294	fbi->fb.fix.accel	= FB_ACCEL_NONE;
295
296	fbi->fb.var.nonstd	= 0;
297	fbi->fb.var.activate	= FB_ACTIVATE_NOW;
298	fbi->fb.var.height	= -1;
299	fbi->fb.var.width	= -1;
300	fbi->fb.var.vmode	= FB_VMODE_NONINTERLACED;
301
302	fbi->fb.fbops		= &vt8500lcd_ops;
303	fbi->fb.flags		= FBINFO_HWACCEL_COPYAREA
304				| FBINFO_HWACCEL_FILLRECT
305				| FBINFO_HWACCEL_YPAN
306				| FBINFO_VIRTFB
307				| FBINFO_PARTIAL_PAN_OK;
308	fbi->fb.node		= -1;
309
310	addr = fbi;
311	addr = addr + sizeof(struct vt8500lcd_info);
312	fbi->fb.pseudo_palette	= addr;
313
314	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
315	if (res == NULL) {
316		dev_err(&pdev->dev, "no I/O memory resource defined\n");
317		return -ENODEV;
318	}
319
320	res = request_mem_region(res->start, resource_size(res), "vt8500lcd");
321	if (res == NULL) {
322		dev_err(&pdev->dev, "failed to request I/O memory\n");
323		return -EBUSY;
324	}
325
326	fbi->regbase = ioremap(res->start, resource_size(res));
327	if (fbi->regbase == NULL) {
328		dev_err(&pdev->dev, "failed to map I/O memory\n");
329		ret = -EBUSY;
330		goto failed_free_res;
331	}
332
333	disp_timing = of_get_display_timings(pdev->dev.of_node);
334	if (!disp_timing) {
335		ret = -EINVAL;
336		goto failed_free_io;
337	}
338
339	ret = of_get_fb_videomode(pdev->dev.of_node, &of_mode,
340							OF_USE_NATIVE_MODE);
341	if (ret)
342		goto failed_free_io;
343
344	ret = of_property_read_u32(pdev->dev.of_node, "bits-per-pixel", &bpp);
345	if (ret)
346		goto failed_free_io;
347
348	/* try allocating the framebuffer */
349	fb_mem_len = of_mode.xres * of_mode.yres * 2 * (bpp / 8);
350	fb_mem_virt = dma_alloc_coherent(&pdev->dev, fb_mem_len, &fb_mem_phys,
351				GFP_KERNEL);
352	if (!fb_mem_virt) {
353		pr_err("%s: Failed to allocate framebuffer\n", __func__);
354		ret = -ENOMEM;
355		goto failed_free_io;
356	}
357
358	fbi->fb.fix.smem_start	= fb_mem_phys;
359	fbi->fb.fix.smem_len	= fb_mem_len;
360	fbi->fb.screen_base	= fb_mem_virt;
361
362	fbi->palette_size	= PAGE_ALIGN(512);
363	fbi->palette_cpu	= dma_alloc_coherent(&pdev->dev,
364						     fbi->palette_size,
365						     &fbi->palette_phys,
366						     GFP_KERNEL);
367	if (fbi->palette_cpu == NULL) {
368		dev_err(&pdev->dev, "Failed to allocate palette buffer\n");
369		ret = -ENOMEM;
370		goto failed_free_io;
371	}
372
373	irq = platform_get_irq(pdev, 0);
374	if (irq < 0) {
375		dev_err(&pdev->dev, "no IRQ defined\n");
376		ret = -ENODEV;
377		goto failed_free_palette;
378	}
379
380	ret = request_irq(irq, vt8500lcd_handle_irq, 0, "LCD", fbi);
381	if (ret) {
382		dev_err(&pdev->dev, "request_irq failed: %d\n", ret);
383		ret = -EBUSY;
384		goto failed_free_palette;
385	}
386
387	init_waitqueue_head(&fbi->wait);
388
389	if (fb_alloc_cmap(&fbi->fb.cmap, 256, 0) < 0) {
390		dev_err(&pdev->dev, "Failed to allocate color map\n");
391		ret = -ENOMEM;
392		goto failed_free_irq;
393	}
394
395	fb_videomode_to_var(&fbi->fb.var, &of_mode);
396
397	fbi->fb.var.xres_virtual	= of_mode.xres;
398	fbi->fb.var.yres_virtual	= of_mode.yres * 2;
399	fbi->fb.var.bits_per_pixel	= bpp;
400
401	ret = vt8500lcd_set_par(&fbi->fb);
402	if (ret) {
403		dev_err(&pdev->dev, "Failed to set parameters\n");
404		goto failed_free_cmap;
405	}
406
407	writel(fbi->fb.fix.smem_start >> 22, fbi->regbase + 0x1c);
408	writel((fbi->palette_phys & 0xfffffe00) | 1, fbi->regbase + 0x18);
409
410	platform_set_drvdata(pdev, fbi);
411
412	ret = register_framebuffer(&fbi->fb);
413	if (ret < 0) {
414		dev_err(&pdev->dev,
415			"Failed to register framebuffer device: %d\n", ret);
416		goto failed_free_cmap;
417	}
418
419	/*
420	 * Ok, now enable the LCD controller
421	 */
422	writel(readl(fbi->regbase) | 1, fbi->regbase);
423
424	return 0;
425
426failed_free_cmap:
427	if (fbi->fb.cmap.len)
428		fb_dealloc_cmap(&fbi->fb.cmap);
429failed_free_irq:
430	free_irq(irq, fbi);
431failed_free_palette:
432	dma_free_coherent(&pdev->dev, fbi->palette_size,
433			  fbi->palette_cpu, fbi->palette_phys);
434failed_free_io:
435	iounmap(fbi->regbase);
436failed_free_res:
437	release_mem_region(res->start, resource_size(res));
438	return ret;
439}
440
441static void vt8500lcd_remove(struct platform_device *pdev)
442{
443	struct vt8500lcd_info *fbi = platform_get_drvdata(pdev);
444	struct resource *res;
445	int irq;
446
447	unregister_framebuffer(&fbi->fb);
448
449	writel(0, fbi->regbase);
450
451	if (fbi->fb.cmap.len)
452		fb_dealloc_cmap(&fbi->fb.cmap);
453
454	irq = platform_get_irq(pdev, 0);
455	free_irq(irq, fbi);
456
457	dma_free_coherent(&pdev->dev, fbi->palette_size,
458			  fbi->palette_cpu, fbi->palette_phys);
459
460	iounmap(fbi->regbase);
461
462	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
463	release_mem_region(res->start, resource_size(res));
464}
465
466static const struct of_device_id via_dt_ids[] = {
467	{ .compatible = "via,vt8500-fb", },
468	{}
469};
470
471static struct platform_driver vt8500lcd_driver = {
472	.probe		= vt8500lcd_probe,
473	.remove_new	= vt8500lcd_remove,
474	.driver		= {
475		.name	= "vt8500-lcd",
476		.of_match_table = of_match_ptr(via_dt_ids),
477	},
478};
479
480module_platform_driver(vt8500lcd_driver);
481
482MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
483MODULE_DESCRIPTION("LCD controller driver for VIA VT8500");
484MODULE_LICENSE("GPL v2");
485MODULE_DEVICE_TABLE(of, via_dt_ids);
486