2 * Simplest possible simple frame-buffer driver, as a platform device
4 * Copyright (c) 2013, Stephen Warren
6 * Based on q40fb.c, which was:
7 * Copyright (C) 2001 Richard Zidlicky <rz@linux-m68k.org>
9 * Also based on offb.c, which was:
10 * Copyright (C) 1997 Geert Uytterhoeven
11 * Copyright (C) 1996 Paul Mackerras
13 * This program is free software; you can redistribute it and/or modify it
14 * under the terms and conditions of the GNU General Public License,
15 * version 2, as published by the Free Software Foundation.
17 * This program is distributed in the hope it will be useful, but WITHOUT
18 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
19 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
23 #include <linux/errno.h>
26 #include <linux/module.h>
27 #include <linux/platform_data/simplefb.h>
28 #include <linux/platform_device.h>
30 static struct fb_fix_screeninfo simplefb_fix = {
32 .type = FB_TYPE_PACKED_PIXELS,
33 .visual = FB_VISUAL_TRUECOLOR,
34 .accel = FB_ACCEL_NONE,
37 static struct fb_var_screeninfo simplefb_var = {
40 .activate = FB_ACTIVATE_NOW,
41 .vmode = FB_VMODE_NONINTERLACED,
44 static int simplefb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
45 u_int transp, struct fb_info *info)
47 u32 *pal = info->pseudo_palette;
48 u32 cr = red >> (16 - info->var.red.length);
49 u32 cg = green >> (16 - info->var.green.length);
50 u32 cb = blue >> (16 - info->var.blue.length);
56 value = (cr << info->var.red.offset) |
57 (cg << info->var.green.offset) |
58 (cb << info->var.blue.offset);
59 if (info->var.transp.length > 0) {
60 u32 mask = (1 << info->var.transp.length) - 1;
61 mask <<= info->var.transp.offset;
69 static struct fb_ops simplefb_ops = {
71 .fb_setcolreg = simplefb_setcolreg,
72 .fb_fillrect = cfb_fillrect,
73 .fb_copyarea = cfb_copyarea,
74 .fb_imageblit = cfb_imageblit,
77 static struct simplefb_format simplefb_formats[] = SIMPLEFB_FORMATS;
79 struct simplefb_params {
83 struct simplefb_format *format;
86 static int simplefb_parse_dt(struct platform_device *pdev,
87 struct simplefb_params *params)
89 struct device_node *np = pdev->dev.of_node;
94 ret = of_property_read_u32(np, "width", ¶ms->width);
96 dev_err(&pdev->dev, "Can't parse width property\n");
100 ret = of_property_read_u32(np, "height", ¶ms->height);
102 dev_err(&pdev->dev, "Can't parse height property\n");
106 ret = of_property_read_u32(np, "stride", ¶ms->stride);
108 dev_err(&pdev->dev, "Can't parse stride property\n");
112 ret = of_property_read_string(np, "format", &format);
114 dev_err(&pdev->dev, "Can't parse format property\n");
117 params->format = NULL;
118 for (i = 0; i < ARRAY_SIZE(simplefb_formats); i++) {
119 if (strcmp(format, simplefb_formats[i].name))
121 params->format = &simplefb_formats[i];
124 if (!params->format) {
125 dev_err(&pdev->dev, "Invalid format value\n");
132 static int simplefb_parse_pd(struct platform_device *pdev,
133 struct simplefb_params *params)
135 struct simplefb_platform_data *pd = pdev->dev.platform_data;
138 params->width = pd->width;
139 params->height = pd->height;
140 params->stride = pd->stride;
142 params->format = NULL;
143 for (i = 0; i < ARRAY_SIZE(simplefb_formats); i++) {
144 if (strcmp(pd->format, simplefb_formats[i].name))
147 params->format = &simplefb_formats[i];
151 if (!params->format) {
152 dev_err(&pdev->dev, "Invalid format value\n");
159 static int simplefb_probe(struct platform_device *pdev)
162 struct simplefb_params params;
163 struct fb_info *info;
164 struct resource *mem;
166 if (fb_get_options("simplefb", NULL))
170 if (pdev->dev.platform_data)
171 ret = simplefb_parse_pd(pdev, ¶ms);
172 else if (pdev->dev.of_node)
173 ret = simplefb_parse_dt(pdev, ¶ms);
178 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
180 dev_err(&pdev->dev, "No memory resource\n");
184 info = framebuffer_alloc(sizeof(u32) * 16, &pdev->dev);
187 platform_set_drvdata(pdev, info);
189 info->fix = simplefb_fix;
190 info->fix.smem_start = mem->start;
191 info->fix.smem_len = resource_size(mem);
192 info->fix.line_length = params.stride;
194 info->var = simplefb_var;
195 info->var.xres = params.width;
196 info->var.yres = params.height;
197 info->var.xres_virtual = params.width;
198 info->var.yres_virtual = params.height;
199 info->var.bits_per_pixel = params.format->bits_per_pixel;
200 info->var.red = params.format->red;
201 info->var.green = params.format->green;
202 info->var.blue = params.format->blue;
203 info->var.transp = params.format->transp;
205 info->apertures = alloc_apertures(1);
206 if (!info->apertures) {
207 framebuffer_release(info);
210 info->apertures->ranges[0].base = info->fix.smem_start;
211 info->apertures->ranges[0].size = info->fix.smem_len;
213 info->fbops = &simplefb_ops;
214 info->flags = FBINFO_DEFAULT | FBINFO_MISC_FIRMWARE;
215 info->screen_base = devm_ioremap(&pdev->dev, info->fix.smem_start,
217 if (!info->screen_base) {
218 framebuffer_release(info);
221 info->pseudo_palette = (void *)(info + 1);
223 ret = register_framebuffer(info);
225 dev_err(&pdev->dev, "Unable to register simplefb: %d\n", ret);
226 framebuffer_release(info);
230 dev_info(&pdev->dev, "fb%d: simplefb registered!\n", info->node);
235 static int simplefb_remove(struct platform_device *pdev)
237 struct fb_info *info = platform_get_drvdata(pdev);
239 unregister_framebuffer(info);
240 framebuffer_release(info);
245 static const struct of_device_id simplefb_of_match[] = {
246 { .compatible = "simple-framebuffer", },
249 MODULE_DEVICE_TABLE(of, simplefb_of_match);
251 static struct platform_driver simplefb_driver = {
253 .name = "simple-framebuffer",
254 .owner = THIS_MODULE,
255 .of_match_table = simplefb_of_match,
257 .probe = simplefb_probe,
258 .remove = simplefb_remove,
260 module_platform_driver(simplefb_driver);
262 MODULE_AUTHOR("Stephen Warren <swarren@wwwdotorg.org>");
263 MODULE_DESCRIPTION("Simple framebuffer driver");
264 MODULE_LICENSE("GPL v2");