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(addr: fbi->regbase) & ~0xf;
113 writel(val: 0, addr: fbi->regbase);
114 while (readl(addr: fbi->regbase + 0x38) & 0x10)
115 /* wait */;
116 writel(val: (((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), addr: fbi->regbase + 0x4);
120 writel(val: (((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), addr: fbi->regbase + 0x8);
124 writel(val: (((info->var.yres - 1) & 0x400) << 2)
125 | ((info->var.xres - 1) & 0x400), addr: fbi->regbase + 0x10);
126 writel(val: 0x80000000, addr: fbi->regbase + 0x20);
127 writel(val: control0 | (reg_bpp << 1) | 0x100, addr: 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(chan: red, bf: &fbi->fb.var.red);
158 val |= chan_to_field(chan: green, bf: &fbi->fb.var.green);
159 val |= chan_to_field(chan: blue, bf: &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(val: (red & 0xf800)
169 | ((green >> 5) & 0x7e0)
170 | ((blue >> 11) & 0x1f),
171 addr: 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(val: 0xffffffff ^ (1 << 3), addr: 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(val: 0xffffffff, addr: 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(val: (1 << 31)
209 | (((info->var.xres_virtual - info->var.xres) * pixlen / 4) << 20)
210 | (off >> 2), addr: 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(regno: i, red: 0, green: 0, blue: 0, transp: 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(cmap: &info->cmap, fb_info: 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(addr: fbi->regbase + 0x38) & (1 << 3))
262 wake_up_interruptible(&fbi->wait);
263
264 writel(val: 0xffffffff, addr: 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(dev: &pdev->dev, size: sizeof(struct vt8500lcd_info)
286 + sizeof(u32) * 16, GFP_KERNEL);
287 if (!fbi)
288 return -ENOMEM;
289
290 strcpy(p: fbi->fb.fix.id, q: "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(offset: res->start, size: 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(np: pdev->dev.of_node);
336 if (!disp_timing) {
337 ret = -EINVAL;
338 goto failed_free_io;
339 }
340
341 ret = of_get_fb_videomode(np: pdev->dev.of_node, fb: &of_mode,
342 OF_USE_NATIVE_MODE);
343 if (ret)
344 goto failed_free_io;
345
346 ret = of_property_read_u32(np: pdev->dev.of_node, propname: "bits-per-pixel", out_value: &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(dev: &pdev->dev, size: fb_mem_len, dma_handle: &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(dev: &pdev->dev,
366 size: fbi->palette_size,
367 dma_handle: &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_io;
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, handler: vt8500lcd_handle_irq, flags: 0, name: "LCD", dev: 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(cmap: &fbi->fb.cmap, len: 256, transp: 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(var: &fbi->fb.var, mode: &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(info: &fbi->fb);
403 if (ret) {
404 dev_err(&pdev->dev, "Failed to set parameters\n");
405 goto failed_free_cmap;
406 }
407
408 writel(val: fbi->fb.fix.smem_start >> 22, addr: fbi->regbase + 0x1c);
409 writel(val: (fbi->palette_phys & 0xfffffe00) | 1, addr: fbi->regbase + 0x18);
410
411 platform_set_drvdata(pdev, data: fbi);
412
413 ret = register_framebuffer(fb_info: &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(addr: fbi->regbase) | 1, addr: fbi->regbase);
424
425 return 0;
426
427failed_free_cmap:
428 if (fbi->fb.cmap.len)
429 fb_dealloc_cmap(cmap: &fbi->fb.cmap);
430failed_free_irq:
431 free_irq(irq, fbi);
432failed_free_palette:
433 dma_free_coherent(dev: &pdev->dev, size: fbi->palette_size,
434 cpu_addr: fbi->palette_cpu, dma_handle: fbi->palette_phys);
435failed_free_io:
436 iounmap(addr: fbi->regbase);
437failed_free_res:
438 release_mem_region(res->start, resource_size(res));
439 return ret;
440}
441
442static void vt8500lcd_remove(struct platform_device *pdev)
443{
444 struct vt8500lcd_info *fbi = platform_get_drvdata(pdev);
445 struct resource *res;
446 int irq;
447
448 unregister_framebuffer(fb_info: &fbi->fb);
449
450 writel(val: 0, addr: fbi->regbase);
451
452 if (fbi->fb.cmap.len)
453 fb_dealloc_cmap(cmap: &fbi->fb.cmap);
454
455 irq = platform_get_irq(pdev, 0);
456 free_irq(irq, fbi);
457
458 dma_free_coherent(dev: &pdev->dev, size: fbi->palette_size,
459 cpu_addr: fbi->palette_cpu, dma_handle: fbi->palette_phys);
460
461 iounmap(addr: fbi->regbase);
462
463 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
464 release_mem_region(res->start, resource_size(res));
465}
466
467static const struct of_device_id via_dt_ids[] = {
468 { .compatible = "via,vt8500-fb", },
469 {}
470};
471
472static struct platform_driver vt8500lcd_driver = {
473 .probe = vt8500lcd_probe,
474 .remove_new = vt8500lcd_remove,
475 .driver = {
476 .name = "vt8500-lcd",
477 .of_match_table = of_match_ptr(via_dt_ids),
478 },
479};
480
481module_platform_driver(vt8500lcd_driver);
482
483MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
484MODULE_DESCRIPTION("LCD controller driver for VIA VT8500");
485MODULE_LICENSE("GPL v2");
486MODULE_DEVICE_TABLE(of, via_dt_ids);
487

source code of linux/drivers/video/fbdev/vt8500lcdfb.c