1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/drivers/video/ep93xx-fb.c
5 * Framebuffer support for the EP93xx series.
7 * Copyright (C) 2007 Bluewater Systems Ltd
10 * Copyright (c) 2009 H Hartley Sweeten <hsweeten@visionengravers.com>
12 * Based on the Cirrus Logic ep93xxfb driver, and various other ep93xxfb
16 #include <linux/platform_device.h>
17 #include <linux/module.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/slab.h>
20 #include <linux/clk.h>
24 #include <linux/platform_data/video-ep93xx.h>
26 /* Vertical Frame Timing Registers */
27 #define EP93XXFB_VLINES_TOTAL 0x0000 /* SW locked */
28 #define EP93XXFB_VSYNC 0x0004 /* SW locked */
29 #define EP93XXFB_VACTIVE 0x0008 /* SW locked */
30 #define EP93XXFB_VBLANK 0x0228 /* SW locked */
31 #define EP93XXFB_VCLK 0x000c /* SW locked */
33 /* Horizontal Frame Timing Registers */
34 #define EP93XXFB_HCLKS_TOTAL 0x0010 /* SW locked */
35 #define EP93XXFB_HSYNC 0x0014 /* SW locked */
36 #define EP93XXFB_HACTIVE 0x0018 /* SW locked */
37 #define EP93XXFB_HBLANK 0x022c /* SW locked */
38 #define EP93XXFB_HCLK 0x001c /* SW locked */
40 /* Frame Buffer Memory Configuration Registers */
41 #define EP93XXFB_SCREEN_PAGE 0x0028
42 #define EP93XXFB_SCREEN_HPAGE 0x002c
43 #define EP93XXFB_SCREEN_LINES 0x0030
44 #define EP93XXFB_LINE_LENGTH 0x0034
45 #define EP93XXFB_VLINE_STEP 0x0038
46 #define EP93XXFB_LINE_CARRY 0x003c /* SW locked */
47 #define EP93XXFB_EOL_OFFSET 0x0230
49 /* Other Video Registers */
50 #define EP93XXFB_BRIGHTNESS 0x0020
51 #define EP93XXFB_ATTRIBS 0x0024 /* SW locked */
52 #define EP93XXFB_SWLOCK 0x007c /* SW locked */
53 #define EP93XXFB_AC_RATE 0x0214
54 #define EP93XXFB_FIFO_LEVEL 0x0234
55 #define EP93XXFB_PIXELMODE 0x0054
56 #define EP93XXFB_PIXELMODE_32BPP (0x7 << 0)
57 #define EP93XXFB_PIXELMODE_24BPP (0x6 << 0)
58 #define EP93XXFB_PIXELMODE_16BPP (0x4 << 0)
59 #define EP93XXFB_PIXELMODE_8BPP (0x2 << 0)
60 #define EP93XXFB_PIXELMODE_SHIFT_1P_24B (0x0 << 3)
61 #define EP93XXFB_PIXELMODE_SHIFT_1P_18B (0x1 << 3)
62 #define EP93XXFB_PIXELMODE_COLOR_LUT (0x0 << 10)
63 #define EP93XXFB_PIXELMODE_COLOR_888 (0x4 << 10)
64 #define EP93XXFB_PIXELMODE_COLOR_555 (0x5 << 10)
65 #define EP93XXFB_PARL_IF_OUT 0x0058
66 #define EP93XXFB_PARL_IF_IN 0x005c
68 /* Blink Control Registers */
69 #define EP93XXFB_BLINK_RATE 0x0040
70 #define EP93XXFB_BLINK_MASK 0x0044
71 #define EP93XXFB_BLINK_PATTRN 0x0048
72 #define EP93XXFB_PATTRN_MASK 0x004c
73 #define EP93XXFB_BKGRND_OFFSET 0x0050
75 /* Hardware Cursor Registers */
76 #define EP93XXFB_CURSOR_ADR_START 0x0060
77 #define EP93XXFB_CURSOR_ADR_RESET 0x0064
78 #define EP93XXFB_CURSOR_SIZE 0x0068
79 #define EP93XXFB_CURSOR_COLOR1 0x006c
80 #define EP93XXFB_CURSOR_COLOR2 0x0070
81 #define EP93XXFB_CURSOR_BLINK_COLOR1 0x021c
82 #define EP93XXFB_CURSOR_BLINK_COLOR2 0x0220
83 #define EP93XXFB_CURSOR_XY_LOC 0x0074
84 #define EP93XXFB_CURSOR_DSCAN_HY_LOC 0x0078
85 #define EP93XXFB_CURSOR_BLINK_RATE_CTRL 0x0224
88 #define EP93XXFB_GRY_SCL_LUTR 0x0080
89 #define EP93XXFB_GRY_SCL_LUTG 0x0280
90 #define EP93XXFB_GRY_SCL_LUTB 0x0300
91 #define EP93XXFB_LUT_SW_CONTROL 0x0218
92 #define EP93XXFB_LUT_SW_CONTROL_SWTCH (1 << 0)
93 #define EP93XXFB_LUT_SW_CONTROL_SSTAT (1 << 1)
94 #define EP93XXFB_COLOR_LUT 0x0400
96 /* Video Signature Registers */
97 #define EP93XXFB_VID_SIG_RSLT_VAL 0x0200
98 #define EP93XXFB_VID_SIG_CTRL 0x0204
99 #define EP93XXFB_VSIG 0x0208
100 #define EP93XXFB_HSIG 0x020c
101 #define EP93XXFB_SIG_CLR_STR 0x0210
103 /* Minimum / Maximum resolutions supported */
104 #define EP93XXFB_MIN_XRES 64
105 #define EP93XXFB_MIN_YRES 64
106 #define EP93XXFB_MAX_XRES 1024
107 #define EP93XXFB_MAX_YRES 768
110 struct ep93xxfb_mach_info *mach_info;
112 struct resource *res;
113 void __iomem *mmio_base;
114 unsigned int pseudo_palette[256];
117 static int check_screenpage_bug = 1;
118 module_param(check_screenpage_bug, int, 0644);
119 MODULE_PARM_DESC(check_screenpage_bug,
120 "Check for bit 27 screen page bug. Default = 1");
122 static inline unsigned int ep93xxfb_readl(struct ep93xx_fbi *fbi,
125 return __raw_readl(fbi->mmio_base + off);
128 static inline void ep93xxfb_writel(struct ep93xx_fbi *fbi,
129 unsigned int val, unsigned int off)
131 __raw_writel(val, fbi->mmio_base + off);
135 * Write to one of the locked raster registers.
137 static inline void ep93xxfb_out_locked(struct ep93xx_fbi *fbi,
138 unsigned int val, unsigned int reg)
141 * We don't need a lock or delay here since the raster register
142 * block will remain unlocked until the next access.
144 ep93xxfb_writel(fbi, 0xaa, EP93XXFB_SWLOCK);
145 ep93xxfb_writel(fbi, val, reg);
148 static void ep93xxfb_set_video_attribs(struct fb_info *info)
150 struct ep93xx_fbi *fbi = info->par;
151 unsigned int attribs;
153 attribs = EP93XXFB_ENABLE;
154 attribs |= fbi->mach_info->flags;
155 ep93xxfb_out_locked(fbi, attribs, EP93XXFB_ATTRIBS);
158 static int ep93xxfb_set_pixelmode(struct fb_info *info)
160 struct ep93xx_fbi *fbi = info->par;
163 info->var.transp.offset = 0;
164 info->var.transp.length = 0;
166 switch (info->var.bits_per_pixel) {
168 val = EP93XXFB_PIXELMODE_8BPP | EP93XXFB_PIXELMODE_COLOR_LUT |
169 EP93XXFB_PIXELMODE_SHIFT_1P_18B;
171 info->var.red.offset = 0;
172 info->var.red.length = 8;
173 info->var.green.offset = 0;
174 info->var.green.length = 8;
175 info->var.blue.offset = 0;
176 info->var.blue.length = 8;
177 info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
181 val = EP93XXFB_PIXELMODE_16BPP | EP93XXFB_PIXELMODE_COLOR_555 |
182 EP93XXFB_PIXELMODE_SHIFT_1P_18B;
184 info->var.red.offset = 11;
185 info->var.red.length = 5;
186 info->var.green.offset = 5;
187 info->var.green.length = 6;
188 info->var.blue.offset = 0;
189 info->var.blue.length = 5;
190 info->fix.visual = FB_VISUAL_TRUECOLOR;
194 val = EP93XXFB_PIXELMODE_24BPP | EP93XXFB_PIXELMODE_COLOR_888 |
195 EP93XXFB_PIXELMODE_SHIFT_1P_24B;
197 info->var.red.offset = 16;
198 info->var.red.length = 8;
199 info->var.green.offset = 8;
200 info->var.green.length = 8;
201 info->var.blue.offset = 0;
202 info->var.blue.length = 8;
203 info->fix.visual = FB_VISUAL_TRUECOLOR;
207 val = EP93XXFB_PIXELMODE_32BPP | EP93XXFB_PIXELMODE_COLOR_888 |
208 EP93XXFB_PIXELMODE_SHIFT_1P_24B;
210 info->var.red.offset = 16;
211 info->var.red.length = 8;
212 info->var.green.offset = 8;
213 info->var.green.length = 8;
214 info->var.blue.offset = 0;
215 info->var.blue.length = 8;
216 info->fix.visual = FB_VISUAL_TRUECOLOR;
223 ep93xxfb_writel(fbi, val, EP93XXFB_PIXELMODE);
227 static void ep93xxfb_set_timing(struct fb_info *info)
229 struct ep93xx_fbi *fbi = info->par;
230 unsigned int vlines_total, hclks_total, start, stop;
232 vlines_total = info->var.yres + info->var.upper_margin +
233 info->var.lower_margin + info->var.vsync_len - 1;
235 hclks_total = info->var.xres + info->var.left_margin +
236 info->var.right_margin + info->var.hsync_len - 1;
238 ep93xxfb_out_locked(fbi, vlines_total, EP93XXFB_VLINES_TOTAL);
239 ep93xxfb_out_locked(fbi, hclks_total, EP93XXFB_HCLKS_TOTAL);
241 start = vlines_total;
242 stop = vlines_total - info->var.vsync_len;
243 ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VSYNC);
245 start = vlines_total - info->var.vsync_len - info->var.upper_margin;
246 stop = info->var.lower_margin - 1;
247 ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VBLANK);
248 ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VACTIVE);
250 start = vlines_total;
251 stop = vlines_total + 1;
252 ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VCLK);
255 stop = hclks_total - info->var.hsync_len;
256 ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HSYNC);
258 start = hclks_total - info->var.hsync_len - info->var.left_margin;
259 stop = info->var.right_margin - 1;
260 ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HBLANK);
261 ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HACTIVE);
265 ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HCLK);
267 ep93xxfb_out_locked(fbi, 0x0, EP93XXFB_LINE_CARRY);
270 static int ep93xxfb_set_par(struct fb_info *info)
272 struct ep93xx_fbi *fbi = info->par;
274 clk_set_rate(fbi->clk, 1000 * PICOS2KHZ(info->var.pixclock));
276 ep93xxfb_set_timing(info);
278 info->fix.line_length = info->var.xres_virtual *
279 info->var.bits_per_pixel / 8;
281 ep93xxfb_writel(fbi, info->fix.smem_start, EP93XXFB_SCREEN_PAGE);
282 ep93xxfb_writel(fbi, info->var.yres - 1, EP93XXFB_SCREEN_LINES);
283 ep93xxfb_writel(fbi, ((info->var.xres * info->var.bits_per_pixel)
284 / 32) - 1, EP93XXFB_LINE_LENGTH);
285 ep93xxfb_writel(fbi, info->fix.line_length / 4, EP93XXFB_VLINE_STEP);
286 ep93xxfb_set_video_attribs(info);
290 static int ep93xxfb_check_var(struct fb_var_screeninfo *var,
291 struct fb_info *info)
295 err = ep93xxfb_set_pixelmode(info);
299 var->xres = max_t(unsigned int, var->xres, EP93XXFB_MIN_XRES);
300 var->xres = min_t(unsigned int, var->xres, EP93XXFB_MAX_XRES);
301 var->xres_virtual = max(var->xres_virtual, var->xres);
303 var->yres = max_t(unsigned int, var->yres, EP93XXFB_MIN_YRES);
304 var->yres = min_t(unsigned int, var->yres, EP93XXFB_MAX_YRES);
305 var->yres_virtual = max(var->yres_virtual, var->yres);
310 static int ep93xxfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
312 unsigned int offset = vma->vm_pgoff << PAGE_SHIFT;
314 if (offset < info->fix.smem_len) {
315 return dma_mmap_wc(info->dev, vma, info->screen_base,
316 info->fix.smem_start, info->fix.smem_len);
322 static int ep93xxfb_blank(int blank_mode, struct fb_info *info)
324 struct ep93xx_fbi *fbi = info->par;
325 unsigned int attribs = ep93xxfb_readl(fbi, EP93XXFB_ATTRIBS);
328 if (fbi->mach_info->blank)
329 fbi->mach_info->blank(blank_mode, info);
330 ep93xxfb_out_locked(fbi, attribs & ~EP93XXFB_ENABLE,
332 clk_disable(fbi->clk);
334 clk_enable(fbi->clk);
335 ep93xxfb_out_locked(fbi, attribs | EP93XXFB_ENABLE,
337 if (fbi->mach_info->blank)
338 fbi->mach_info->blank(blank_mode, info);
344 static inline int ep93xxfb_convert_color(int val, int width)
346 return ((val << width) + 0x7fff - val) >> 16;
349 static int ep93xxfb_setcolreg(unsigned int regno, unsigned int red,
350 unsigned int green, unsigned int blue,
351 unsigned int transp, struct fb_info *info)
353 struct ep93xx_fbi *fbi = info->par;
354 unsigned int *pal = info->pseudo_palette;
355 unsigned int ctrl, i, rgb, lut_current, lut_stat;
357 switch (info->fix.visual) {
358 case FB_VISUAL_PSEUDOCOLOR:
361 rgb = ((red & 0xff00) << 8) | (green & 0xff00) |
362 ((blue & 0xff00) >> 8);
365 ep93xxfb_writel(fbi, rgb, (EP93XXFB_COLOR_LUT + (regno << 2)));
366 ctrl = ep93xxfb_readl(fbi, EP93XXFB_LUT_SW_CONTROL);
367 lut_stat = !!(ctrl & EP93XXFB_LUT_SW_CONTROL_SSTAT);
368 lut_current = !!(ctrl & EP93XXFB_LUT_SW_CONTROL_SWTCH);
370 if (lut_stat == lut_current) {
371 for (i = 0; i < 256; i++) {
372 ep93xxfb_writel(fbi, pal[i],
373 EP93XXFB_COLOR_LUT + (i << 2));
377 ctrl ^ EP93XXFB_LUT_SW_CONTROL_SWTCH,
378 EP93XXFB_LUT_SW_CONTROL);
382 case FB_VISUAL_TRUECOLOR:
386 red = ep93xxfb_convert_color(red, info->var.red.length);
387 green = ep93xxfb_convert_color(green, info->var.green.length);
388 blue = ep93xxfb_convert_color(blue, info->var.blue.length);
389 transp = ep93xxfb_convert_color(transp,
390 info->var.transp.length);
392 pal[regno] = (red << info->var.red.offset) |
393 (green << info->var.green.offset) |
394 (blue << info->var.blue.offset) |
395 (transp << info->var.transp.offset);
405 static const struct fb_ops ep93xxfb_ops = {
406 .owner = THIS_MODULE,
407 .fb_check_var = ep93xxfb_check_var,
408 .fb_set_par = ep93xxfb_set_par,
409 .fb_blank = ep93xxfb_blank,
410 .fb_fillrect = cfb_fillrect,
411 .fb_copyarea = cfb_copyarea,
412 .fb_imageblit = cfb_imageblit,
413 .fb_setcolreg = ep93xxfb_setcolreg,
414 .fb_mmap = ep93xxfb_mmap,
417 static int ep93xxfb_alloc_videomem(struct fb_info *info)
419 char __iomem *virt_addr;
420 dma_addr_t phys_addr;
421 unsigned int fb_size;
423 /* Maximum 16bpp -> used memory is maximum x*y*2 bytes */
424 fb_size = EP93XXFB_MAX_XRES * EP93XXFB_MAX_YRES * 2;
426 virt_addr = dma_alloc_wc(info->dev, fb_size, &phys_addr, GFP_KERNEL);
431 * There is a bug in the ep93xx framebuffer which causes problems
432 * if bit 27 of the physical address is set.
433 * See: https://marc.info/?l=linux-arm-kernel&m=110061245502000&w=2
434 * There does not seem to be any official errata for this, but I
435 * have confirmed the problem exists on my hardware (ep9315) at
438 if (check_screenpage_bug && phys_addr & (1 << 27)) {
439 dev_err(info->dev, "ep93xx framebuffer bug. phys addr (0x%x) "
440 "has bit 27 set: cannot init framebuffer\n",
443 dma_free_coherent(info->dev, fb_size, virt_addr, phys_addr);
447 info->fix.smem_start = phys_addr;
448 info->fix.smem_len = fb_size;
449 info->screen_base = virt_addr;
454 static void ep93xxfb_dealloc_videomem(struct fb_info *info)
456 if (info->screen_base)
457 dma_free_coherent(info->dev, info->fix.smem_len,
458 info->screen_base, info->fix.smem_start);
461 static int ep93xxfb_probe(struct platform_device *pdev)
463 struct ep93xxfb_mach_info *mach_info = dev_get_platdata(&pdev->dev);
464 struct fb_info *info;
465 struct ep93xx_fbi *fbi;
466 struct resource *res;
473 info = framebuffer_alloc(sizeof(struct ep93xx_fbi), &pdev->dev);
477 platform_set_drvdata(pdev, info);
479 fbi->mach_info = mach_info;
481 err = fb_alloc_cmap(&info->cmap, 256, 0);
485 err = ep93xxfb_alloc_videomem(info);
487 goto failed_videomem;
489 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
492 goto failed_resource;
496 * FIXME - We don't do a request_mem_region here because we are
497 * sharing the register space with the backlight driver (see
498 * drivers/video/backlight/ep93xx_bl.c) and doing so will cause
499 * the second loaded driver to return -EBUSY.
501 * NOTE: No locking is required; the backlight does not touch
502 * any of the framebuffer registers.
505 fbi->mmio_base = devm_ioremap(&pdev->dev, res->start,
507 if (!fbi->mmio_base) {
509 goto failed_resource;
512 strcpy(info->fix.id, pdev->name);
513 info->fbops = &ep93xxfb_ops;
514 info->fix.type = FB_TYPE_PACKED_PIXELS;
515 info->fix.accel = FB_ACCEL_NONE;
516 info->var.activate = FB_ACTIVATE_NOW;
517 info->var.vmode = FB_VMODE_NONINTERLACED;
518 info->flags = FBINFO_DEFAULT;
520 info->state = FBINFO_STATE_RUNNING;
521 info->pseudo_palette = &fbi->pseudo_palette;
523 fb_get_options("ep93xx-fb", &video_mode);
524 err = fb_find_mode(&info->var, info, video_mode,
527 dev_err(info->dev, "No suitable video mode found\n");
529 goto failed_resource;
532 if (mach_info->setup) {
533 err = mach_info->setup(pdev);
535 goto failed_resource;
538 err = ep93xxfb_check_var(&info->var, info);
542 fbi->clk = devm_clk_get(&pdev->dev, NULL);
543 if (IS_ERR(fbi->clk)) {
544 err = PTR_ERR(fbi->clk);
549 ep93xxfb_set_par(info);
550 clk_enable(fbi->clk);
552 err = register_framebuffer(info);
556 dev_info(info->dev, "registered. Mode = %dx%d-%d\n",
557 info->var.xres, info->var.yres, info->var.bits_per_pixel);
561 if (fbi->mach_info->teardown)
562 fbi->mach_info->teardown(pdev);
564 ep93xxfb_dealloc_videomem(info);
566 fb_dealloc_cmap(&info->cmap);
573 static int ep93xxfb_remove(struct platform_device *pdev)
575 struct fb_info *info = platform_get_drvdata(pdev);
576 struct ep93xx_fbi *fbi = info->par;
578 unregister_framebuffer(info);
579 clk_disable(fbi->clk);
580 ep93xxfb_dealloc_videomem(info);
581 fb_dealloc_cmap(&info->cmap);
583 if (fbi->mach_info->teardown)
584 fbi->mach_info->teardown(pdev);
591 static struct platform_driver ep93xxfb_driver = {
592 .probe = ep93xxfb_probe,
593 .remove = ep93xxfb_remove,
598 module_platform_driver(ep93xxfb_driver);
600 MODULE_DESCRIPTION("EP93XX Framebuffer Driver");
601 MODULE_ALIAS("platform:ep93xx-fb");
602 MODULE_AUTHOR("Ryan Mallon, "
603 "H Hartley Sweeten <hsweeten@visionengravers.com");
604 MODULE_LICENSE("GPL");