vt8500lcdfb.c

  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_DEFAULT_DMAMEM_OPS_RDWR,
245	.fb_set_par	= vt8500lcd_set_par,
246	.fb_setcolreg	= vt8500lcd_setcolreg,
247	.fb_fillrect	= wmt_ge_fillrect,
248	.fb_copyarea	= wmt_ge_copyarea,
249	.fb_imageblit	= sys_imageblit,
250	.fb_sync	= wmt_ge_sync,
251	.fb_ioctl	= vt8500lcd_ioctl,
252	.fb_pan_display	= vt8500lcd_pan_display,
253	.fb_blank	= vt8500lcd_blank,
254	// .fb_mmap needs DMA mmap
255};
256
257static irqreturn_t vt8500lcd_handle_irq(int irq, void *dev_id)
258{
259	struct vt8500lcd_info *fbi = dev_id;
260
261	if (readl(fbi->regbase + 0x38) & (1 << 3))
262		wake_up_interruptible(&fbi->wait);
263
264	writel(0xffffffff, fbi->regbase + 0x38);
265	return IRQ_HANDLED;
266}
267
268static int vt8500lcd_probe(struct platform_device *pdev)
269{
270	struct vt8500lcd_info *fbi;
271	struct resource *res;
272	struct display_timings *disp_timing;
273	void *addr;
274	int irq, ret;
275
276	struct fb_videomode	of_mode;
277	u32			bpp;
278	dma_addr_t fb_mem_phys;
279	unsigned long fb_mem_len;
280	void *fb_mem_virt;
281
282	ret = -ENOMEM;
283	fbi = NULL;
284
285	fbi = devm_kzalloc(&pdev->dev, sizeof(struct vt8500lcd_info)
286			+ sizeof(u32) * 16, GFP_KERNEL);
287	if (!fbi)
288		return -ENOMEM;
289
290	strcpy(fbi->fb.fix.id, "VT8500 LCD");
291
292	fbi->fb.fix.type	= FB_TYPE_PACKED_PIXELS;
293	fbi->fb.fix.xpanstep	= 0;
294	fbi->fb.fix.ypanstep	= 1;
295	fbi->fb.fix.ywrapstep	= 0;
296	fbi->fb.fix.accel	= FB_ACCEL_NONE;
297
298	fbi->fb.var.nonstd	= 0;
299	fbi->fb.var.activate	= FB_ACTIVATE_NOW;
300	fbi->fb.var.height	= -1;
301	fbi->fb.var.width	= -1;
302	fbi->fb.var.vmode	= FB_VMODE_NONINTERLACED;
303
304	fbi->fb.fbops		= &vt8500lcd_ops;
305	fbi->fb.flags		= FBINFO_HWACCEL_COPYAREA
306				| FBINFO_HWACCEL_FILLRECT
307				| FBINFO_HWACCEL_YPAN
308				| FBINFO_VIRTFB
309				| FBINFO_PARTIAL_PAN_OK;
310	fbi->fb.node		= -1;
311
312	addr = fbi;
313	addr = addr + sizeof(struct vt8500lcd_info);
314	fbi->fb.pseudo_palette	= addr;
315
316	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
317	if (res == NULL) {
318		dev_err(&pdev->dev, "no I/O memory resource defined\n");
319		return -ENODEV;
320	}
321
322	res = request_mem_region(res->start, resource_size(res), "vt8500lcd");
323	if (res == NULL) {
324		dev_err(&pdev->dev, "failed to request I/O memory\n");
325		return -EBUSY;
326	}
327
328	fbi->regbase = ioremap(res->start, resource_size(res));
329	if (fbi->regbase == NULL) {
330		dev_err(&pdev->dev, "failed to map I/O memory\n");
331		ret = -EBUSY;
332		goto failed_free_res;
333	}
334
335	disp_timing = of_get_display_timings(pdev->dev.of_node);
336	if (!disp_timing) {
337		ret = -EINVAL;
338		goto failed_free_io;
339	}
340
341	ret = of_get_fb_videomode(pdev->dev.of_node, &of_mode,
342							OF_USE_NATIVE_MODE);
343	if (ret)
344		goto failed_free_io;
345
346	ret = of_property_read_u32(pdev->dev.of_node, "bits-per-pixel", &bpp);
347	if (ret)
348		goto failed_free_io;
349
350	/* try allocating the framebuffer */
351	fb_mem_len = of_mode.xres * of_mode.yres * 2 * (bpp / 8);
352	fb_mem_virt = dma_alloc_coherent(&pdev->dev, fb_mem_len, &fb_mem_phys,
353				GFP_KERNEL);
354	if (!fb_mem_virt) {
355		pr_err("%s: Failed to allocate framebuffer\n", __func__);
356		ret = -ENOMEM;
357		goto failed_free_io;
358	}
359
360	fbi->fb.fix.smem_start	= fb_mem_phys;
361	fbi->fb.fix.smem_len	= fb_mem_len;
362	fbi->fb.screen_buffer	= fb_mem_virt;
363
364	fbi->palette_size	= PAGE_ALIGN(512);
365	fbi->palette_cpu	= dma_alloc_coherent(&pdev->dev,
366						     fbi->palette_size,
367						     &fbi->palette_phys,
368						     GFP_KERNEL);
369	if (fbi->palette_cpu == NULL) {
370		dev_err(&pdev->dev, "Failed to allocate palette buffer\n");
371		ret = -ENOMEM;
372		goto failed_free_mem_virt;
373	}
374
375	irq = platform_get_irq(pdev, 0);
376	if (irq < 0) {
377		ret = -ENODEV;
378		goto failed_free_palette;
379	}
380
381	ret = request_irq(irq, vt8500lcd_handle_irq, 0, "LCD", fbi);
382	if (ret) {
383		dev_err(&pdev->dev, "request_irq failed: %d\n", ret);
384		ret = -EBUSY;
385		goto failed_free_palette;
386	}
387
388	init_waitqueue_head(&fbi->wait);
389
390	if (fb_alloc_cmap(&fbi->fb.cmap, 256, 0) < 0) {
391		dev_err(&pdev->dev, "Failed to allocate color map\n");
392		ret = -ENOMEM;
393		goto failed_free_irq;
394	}
395
396	fb_videomode_to_var(&fbi->fb.var, &of_mode);
397
398	fbi->fb.var.xres_virtual	= of_mode.xres;
399	fbi->fb.var.yres_virtual	= of_mode.yres * 2;
400	fbi->fb.var.bits_per_pixel	= bpp;
401
402	ret = vt8500lcd_set_par(&fbi->fb);
403	if (ret) {
404		dev_err(&pdev->dev, "Failed to set parameters\n");
405		goto failed_free_cmap;
406	}
407
408	writel(fbi->fb.fix.smem_start >> 22, fbi->regbase + 0x1c);
409	writel((fbi->palette_phys & 0xfffffe00) | 1, fbi->regbase + 0x18);
410
411	platform_set_drvdata(pdev, fbi);
412
413	ret = register_framebuffer(&fbi->fb);
414	if (ret < 0) {
415		dev_err(&pdev->dev,
416			"Failed to register framebuffer device: %d\n", ret);
417		goto failed_free_cmap;
418	}
419
420	/*
421	 * Ok, now enable the LCD controller
422	 */
423	writel(readl(fbi->regbase) | 1, fbi->regbase);
424
425	return 0;
426
427failed_free_cmap:
428	if (fbi->fb.cmap.len)
429		fb_dealloc_cmap(&fbi->fb.cmap);
430failed_free_irq:
431	free_irq(irq, fbi);
432failed_free_palette:
433	dma_free_coherent(&pdev->dev, fbi->palette_size,
434			  fbi->palette_cpu, fbi->palette_phys);
435failed_free_mem_virt:
436	dma_free_coherent(&pdev->dev, fbi->fb.fix.smem_len,
437			  fbi->fb.screen_buffer, fbi->fb.fix.smem_start);
438failed_free_io:
439	iounmap(fbi->regbase);
440failed_free_res:
441	release_mem_region(res->start, resource_size(res));
442	return ret;
443}
444
445static void vt8500lcd_remove(struct platform_device *pdev)
446{
447	struct vt8500lcd_info *fbi = platform_get_drvdata(pdev);
448	struct resource *res;
449	int irq;
450
451	unregister_framebuffer(&fbi->fb);
452
453	writel(0, fbi->regbase);
454
455	if (fbi->fb.cmap.len)
456		fb_dealloc_cmap(&fbi->fb.cmap);
457
458	irq = platform_get_irq(pdev, 0);
459	free_irq(irq, fbi);
460
461	dma_free_coherent(&pdev->dev, fbi->palette_size,
462			  fbi->palette_cpu, fbi->palette_phys);
463
464	iounmap(fbi->regbase);
465
466	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
467	release_mem_region(res->start, resource_size(res));
468}
469
470static const struct of_device_id via_dt_ids[] = {
471	{ .compatible = "via,vt8500-fb", },
472	{}
473};
474
475static struct platform_driver vt8500lcd_driver = {
476	.probe		= vt8500lcd_probe,
477	.remove		= vt8500lcd_remove,
478	.driver		= {
479		.name	= "vt8500-lcd",
480		.of_match_table = of_match_ptr(via_dt_ids),
481	},
482};
483
484module_platform_driver(vt8500lcd_driver);
485
486MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
487MODULE_DESCRIPTION("LCD controller driver for VIA VT8500");
488MODULE_LICENSE("GPL v2");
489MODULE_DEVICE_TABLE(of, via_dt_ids);