1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/drivers/video/vt8500lcdfb.c
5 * Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
7 * Based on skeletonfb.c and pxafb.c
10 #include <linux/delay.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/errno.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
17 #include <linux/kernel.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>
26 #include "vt8500lcdfb.h"
27 #include "wmt_ge_rops.h"
31 #include <linux/of_fdt.h>
32 #include <linux/memblock.h>
36 #define to_vt8500lcd_info(__info) container_of(__info, \
37 struct vt8500lcd_info, fb)
39 static int vt8500lcd_set_par(struct fb_info *info)
41 struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
42 int reg_bpp = 5; /* 16bpp */
44 unsigned long control0;
49 if (info->var.bits_per_pixel <= 8) {
51 info->var.red.offset = 0;
52 info->var.red.length = info->var.bits_per_pixel;
53 info->var.red.msb_right = 0;
55 info->var.green.offset = 0;
56 info->var.green.length = info->var.bits_per_pixel;
57 info->var.green.msb_right = 0;
59 info->var.blue.offset = 0;
60 info->var.blue.length = info->var.bits_per_pixel;
61 info->var.blue.msb_right = 0;
63 info->var.transp.offset = 0;
64 info->var.transp.length = 0;
65 info->var.transp.msb_right = 0;
67 info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
68 info->fix.line_length = info->var.xres_virtual /
69 (8/info->var.bits_per_pixel);
72 info->var.transp.offset = 0;
73 info->var.transp.length = 0;
74 info->var.transp.msb_right = 0;
76 if (info->var.bits_per_pixel == 16) {
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;
88 /* Equal depths per channel */
89 info->var.red.offset = info->var.bits_per_pixel
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;
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;
107 for (i = 0; i < 8; i++) {
108 if (bpp_values[i] == info->var.bits_per_pixel)
112 control0 = readl(fbi->regbase) & ~0xf;
113 writel(0, fbi->regbase);
114 while (readl(fbi->regbase + 0x38) & 0x10)
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);
132 static inline u_int chan_to_field(u_int chan, struct fb_bitfield *bf)
135 chan >>= 16 - bf->length;
136 return chan << bf->offset;
139 static 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);
148 if (info->var.grayscale)
150 (19595 * red + 38470 * green + 7471 * blue) >> 16;
152 switch (fbi->fb.fix.visual) {
153 case FB_VISUAL_TRUECOLOR:
155 u32 *pal = fbi->fb.pseudo_palette;
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);
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);
178 static int vt8500lcd_ioctl(struct fb_info *info, unsigned int cmd,
182 struct vt8500lcd_info *fbi = to_vt8500lcd_info(info);
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);
200 static int vt8500lcd_pan_display(struct fb_var_screeninfo *var,
201 struct fb_info *info)
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);
209 | (((info->var.xres_virtual - info->var.xres) * pixlen / 4) << 20)
210 | (off >> 2), fbi->regbase + 0x20);
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.
220 static int vt8500lcd_blank(int blank, struct fb_info *info)
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 case FB_BLANK_UNBLANK:
234 if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR ||
235 info->fix.visual == FB_VISUAL_STATIC_PSEUDOCOLOR)
236 fb_set_cmap(&info->cmap, info);
241 static const struct fb_ops vt8500lcd_ops = {
242 .owner = THIS_MODULE,
243 .fb_set_par = vt8500lcd_set_par,
244 .fb_setcolreg = vt8500lcd_setcolreg,
245 .fb_fillrect = wmt_ge_fillrect,
246 .fb_copyarea = wmt_ge_copyarea,
247 .fb_imageblit = sys_imageblit,
248 .fb_sync = wmt_ge_sync,
249 .fb_ioctl = vt8500lcd_ioctl,
250 .fb_pan_display = vt8500lcd_pan_display,
251 .fb_blank = vt8500lcd_blank,
254 static irqreturn_t vt8500lcd_handle_irq(int irq, void *dev_id)
256 struct vt8500lcd_info *fbi = dev_id;
258 if (readl(fbi->regbase + 0x38) & (1 << 3))
259 wake_up_interruptible(&fbi->wait);
261 writel(0xffffffff, fbi->regbase + 0x38);
265 static int vt8500lcd_probe(struct platform_device *pdev)
267 struct vt8500lcd_info *fbi;
268 struct resource *res;
269 struct display_timings *disp_timing;
273 struct fb_videomode of_mode;
275 dma_addr_t fb_mem_phys;
276 unsigned long fb_mem_len;
282 fbi = devm_kzalloc(&pdev->dev, sizeof(struct vt8500lcd_info)
283 + sizeof(u32) * 16, GFP_KERNEL);
287 strcpy(fbi->fb.fix.id, "VT8500 LCD");
289 fbi->fb.fix.type = FB_TYPE_PACKED_PIXELS;
290 fbi->fb.fix.xpanstep = 0;
291 fbi->fb.fix.ypanstep = 1;
292 fbi->fb.fix.ywrapstep = 0;
293 fbi->fb.fix.accel = FB_ACCEL_NONE;
295 fbi->fb.var.nonstd = 0;
296 fbi->fb.var.activate = FB_ACTIVATE_NOW;
297 fbi->fb.var.height = -1;
298 fbi->fb.var.width = -1;
299 fbi->fb.var.vmode = FB_VMODE_NONINTERLACED;
301 fbi->fb.fbops = &vt8500lcd_ops;
302 fbi->fb.flags = FBINFO_DEFAULT
303 | FBINFO_HWACCEL_COPYAREA
304 | FBINFO_HWACCEL_FILLRECT
305 | FBINFO_HWACCEL_YPAN
307 | FBINFO_PARTIAL_PAN_OK;
311 addr = addr + sizeof(struct vt8500lcd_info);
312 fbi->fb.pseudo_palette = addr;
314 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
316 dev_err(&pdev->dev, "no I/O memory resource defined\n");
320 res = request_mem_region(res->start, resource_size(res), "vt8500lcd");
322 dev_err(&pdev->dev, "failed to request I/O memory\n");
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");
330 goto failed_free_res;
333 disp_timing = of_get_display_timings(pdev->dev.of_node);
339 ret = of_get_fb_videomode(pdev->dev.of_node, &of_mode,
344 ret = of_property_read_u32(pdev->dev.of_node, "bits-per-pixel", &bpp);
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,
353 pr_err("%s: Failed to allocate framebuffer\n", __func__);
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;
362 fbi->palette_size = PAGE_ALIGN(512);
363 fbi->palette_cpu = dma_alloc_coherent(&pdev->dev,
367 if (fbi->palette_cpu == NULL) {
368 dev_err(&pdev->dev, "Failed to allocate palette buffer\n");
373 irq = platform_get_irq(pdev, 0);
375 dev_err(&pdev->dev, "no IRQ defined\n");
377 goto failed_free_palette;
380 ret = request_irq(irq, vt8500lcd_handle_irq, 0, "LCD", fbi);
382 dev_err(&pdev->dev, "request_irq failed: %d\n", ret);
384 goto failed_free_palette;
387 init_waitqueue_head(&fbi->wait);
389 if (fb_alloc_cmap(&fbi->fb.cmap, 256, 0) < 0) {
390 dev_err(&pdev->dev, "Failed to allocate color map\n");
392 goto failed_free_irq;
395 fb_videomode_to_var(&fbi->fb.var, &of_mode);
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;
401 ret = vt8500lcd_set_par(&fbi->fb);
403 dev_err(&pdev->dev, "Failed to set parameters\n");
404 goto failed_free_cmap;
407 writel(fbi->fb.fix.smem_start >> 22, fbi->regbase + 0x1c);
408 writel((fbi->palette_phys & 0xfffffe00) | 1, fbi->regbase + 0x18);
410 platform_set_drvdata(pdev, fbi);
412 ret = register_framebuffer(&fbi->fb);
415 "Failed to register framebuffer device: %d\n", ret);
416 goto failed_free_cmap;
420 * Ok, now enable the LCD controller
422 writel(readl(fbi->regbase) | 1, fbi->regbase);
427 if (fbi->fb.cmap.len)
428 fb_dealloc_cmap(&fbi->fb.cmap);
432 dma_free_coherent(&pdev->dev, fbi->palette_size,
433 fbi->palette_cpu, fbi->palette_phys);
435 iounmap(fbi->regbase);
437 release_mem_region(res->start, resource_size(res));
441 static int vt8500lcd_remove(struct platform_device *pdev)
443 struct vt8500lcd_info *fbi = platform_get_drvdata(pdev);
444 struct resource *res;
447 unregister_framebuffer(&fbi->fb);
449 writel(0, fbi->regbase);
451 if (fbi->fb.cmap.len)
452 fb_dealloc_cmap(&fbi->fb.cmap);
454 irq = platform_get_irq(pdev, 0);
457 dma_free_coherent(&pdev->dev, fbi->palette_size,
458 fbi->palette_cpu, fbi->palette_phys);
460 iounmap(fbi->regbase);
462 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
463 release_mem_region(res->start, resource_size(res));
468 static const struct of_device_id via_dt_ids[] = {
469 { .compatible = "via,vt8500-fb", },
473 static struct platform_driver vt8500lcd_driver = {
474 .probe = vt8500lcd_probe,
475 .remove = vt8500lcd_remove,
477 .name = "vt8500-lcd",
478 .of_match_table = of_match_ptr(via_dt_ids),
482 module_platform_driver(vt8500lcd_driver);
484 MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
485 MODULE_DESCRIPTION("LCD controller driver for VIA VT8500");
486 MODULE_LICENSE("GPL v2");
487 MODULE_DEVICE_TABLE(of, via_dt_ids);