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26549c8d SW |
1 | /* |
2 | * Simplest possible simple frame-buffer driver, as a platform device | |
3 | * | |
4 | * Copyright (c) 2013, Stephen Warren | |
5 | * | |
6 | * Based on q40fb.c, which was: | |
7 | * Copyright (C) 2001 Richard Zidlicky <rz@linux-m68k.org> | |
8 | * | |
9 | * Also based on offb.c, which was: | |
10 | * Copyright (C) 1997 Geert Uytterhoeven | |
11 | * Copyright (C) 1996 Paul Mackerras | |
12 | * | |
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. | |
16 | * | |
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 | |
20 | * more details. | |
21 | */ | |
22 | ||
23 | #include <linux/errno.h> | |
24 | #include <linux/fb.h> | |
25 | #include <linux/io.h> | |
26 | #include <linux/module.h> | |
27 | #include <linux/platform_device.h> | |
28 | ||
29 | static struct fb_fix_screeninfo simplefb_fix = { | |
30 | .id = "simple", | |
31 | .type = FB_TYPE_PACKED_PIXELS, | |
32 | .visual = FB_VISUAL_TRUECOLOR, | |
33 | .accel = FB_ACCEL_NONE, | |
34 | }; | |
35 | ||
36 | static struct fb_var_screeninfo simplefb_var = { | |
37 | .height = -1, | |
38 | .width = -1, | |
39 | .activate = FB_ACTIVATE_NOW, | |
40 | .vmode = FB_VMODE_NONINTERLACED, | |
41 | }; | |
42 | ||
43 | static int simplefb_setcolreg(u_int regno, u_int red, u_int green, u_int blue, | |
44 | u_int transp, struct fb_info *info) | |
45 | { | |
46 | u32 *pal = info->pseudo_palette; | |
47 | u32 cr = red >> (16 - info->var.red.length); | |
48 | u32 cg = green >> (16 - info->var.green.length); | |
49 | u32 cb = blue >> (16 - info->var.blue.length); | |
50 | u32 value; | |
51 | ||
52 | if (regno >= 16) | |
53 | return -EINVAL; | |
54 | ||
55 | value = (cr << info->var.red.offset) | | |
56 | (cg << info->var.green.offset) | | |
57 | (cb << info->var.blue.offset); | |
58 | if (info->var.transp.length > 0) { | |
59 | u32 mask = (1 << info->var.transp.length) - 1; | |
60 | mask <<= info->var.transp.offset; | |
61 | value |= mask; | |
62 | } | |
63 | pal[regno] = value; | |
64 | ||
65 | return 0; | |
66 | } | |
67 | ||
68 | static struct fb_ops simplefb_ops = { | |
69 | .owner = THIS_MODULE, | |
70 | .fb_setcolreg = simplefb_setcolreg, | |
71 | .fb_fillrect = cfb_fillrect, | |
72 | .fb_copyarea = cfb_copyarea, | |
73 | .fb_imageblit = cfb_imageblit, | |
74 | }; | |
75 | ||
76 | struct simplefb_format { | |
77 | const char *name; | |
78 | u32 bits_per_pixel; | |
79 | struct fb_bitfield red; | |
80 | struct fb_bitfield green; | |
81 | struct fb_bitfield blue; | |
82 | struct fb_bitfield transp; | |
83 | }; | |
84 | ||
85 | static struct simplefb_format simplefb_formats[] = { | |
86 | { "r5g6b5", 16, {11, 5}, {5, 6}, {0, 5}, {0, 0} }, | |
87 | }; | |
88 | ||
89 | struct simplefb_params { | |
90 | u32 width; | |
91 | u32 height; | |
92 | u32 stride; | |
93 | struct simplefb_format *format; | |
94 | }; | |
95 | ||
96 | static int simplefb_parse_dt(struct platform_device *pdev, | |
97 | struct simplefb_params *params) | |
98 | { | |
99 | struct device_node *np = pdev->dev.of_node; | |
100 | int ret; | |
101 | const char *format; | |
102 | int i; | |
103 | ||
104 | ret = of_property_read_u32(np, "width", ¶ms->width); | |
105 | if (ret) { | |
106 | dev_err(&pdev->dev, "Can't parse width property\n"); | |
107 | return ret; | |
108 | } | |
109 | ||
110 | ret = of_property_read_u32(np, "height", ¶ms->height); | |
111 | if (ret) { | |
112 | dev_err(&pdev->dev, "Can't parse height property\n"); | |
113 | return ret; | |
114 | } | |
115 | ||
116 | ret = of_property_read_u32(np, "stride", ¶ms->stride); | |
117 | if (ret) { | |
118 | dev_err(&pdev->dev, "Can't parse stride property\n"); | |
119 | return ret; | |
120 | } | |
121 | ||
122 | ret = of_property_read_string(np, "format", &format); | |
123 | if (ret) { | |
124 | dev_err(&pdev->dev, "Can't parse format property\n"); | |
125 | return ret; | |
126 | } | |
127 | params->format = NULL; | |
128 | for (i = 0; i < ARRAY_SIZE(simplefb_formats); i++) { | |
129 | if (strcmp(format, simplefb_formats[i].name)) | |
130 | continue; | |
131 | params->format = &simplefb_formats[i]; | |
132 | break; | |
133 | } | |
134 | if (!params->format) { | |
135 | dev_err(&pdev->dev, "Invalid format value\n"); | |
136 | return -EINVAL; | |
137 | } | |
138 | ||
139 | return 0; | |
140 | } | |
141 | ||
142 | static int simplefb_probe(struct platform_device *pdev) | |
143 | { | |
144 | int ret; | |
145 | struct simplefb_params params; | |
146 | struct fb_info *info; | |
147 | struct resource *mem; | |
148 | ||
149 | if (fb_get_options("simplefb", NULL)) | |
150 | return -ENODEV; | |
151 | ||
152 | ret = simplefb_parse_dt(pdev, ¶ms); | |
153 | if (ret) | |
154 | return ret; | |
155 | ||
156 | mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
157 | if (!mem) { | |
158 | dev_err(&pdev->dev, "No memory resource\n"); | |
159 | return -EINVAL; | |
160 | } | |
161 | ||
162 | info = framebuffer_alloc(sizeof(u32) * 16, &pdev->dev); | |
163 | if (!info) | |
164 | return -ENOMEM; | |
165 | platform_set_drvdata(pdev, info); | |
166 | ||
167 | info->fix = simplefb_fix; | |
168 | info->fix.smem_start = mem->start; | |
169 | info->fix.smem_len = resource_size(mem); | |
170 | info->fix.line_length = params.stride; | |
171 | ||
172 | info->var = simplefb_var; | |
173 | info->var.xres = params.width; | |
174 | info->var.yres = params.height; | |
175 | info->var.xres_virtual = params.width; | |
176 | info->var.yres_virtual = params.height; | |
177 | info->var.bits_per_pixel = params.format->bits_per_pixel; | |
178 | info->var.red = params.format->red; | |
179 | info->var.green = params.format->green; | |
180 | info->var.blue = params.format->blue; | |
181 | info->var.transp = params.format->transp; | |
182 | ||
183 | info->fbops = &simplefb_ops; | |
184 | info->flags = FBINFO_DEFAULT; | |
185 | info->screen_base = devm_ioremap(&pdev->dev, info->fix.smem_start, | |
186 | info->fix.smem_len); | |
187 | if (!info->screen_base) { | |
188 | framebuffer_release(info); | |
189 | return -ENODEV; | |
190 | } | |
191 | info->pseudo_palette = (void *)(info + 1); | |
192 | ||
193 | ret = register_framebuffer(info); | |
194 | if (ret < 0) { | |
195 | dev_err(&pdev->dev, "Unable to register simplefb: %d\n", ret); | |
196 | framebuffer_release(info); | |
197 | return ret; | |
198 | } | |
199 | ||
200 | dev_info(&pdev->dev, "fb%d: simplefb registered!\n", info->node); | |
201 | ||
202 | return 0; | |
203 | } | |
204 | ||
205 | static int simplefb_remove(struct platform_device *pdev) | |
206 | { | |
207 | struct fb_info *info = platform_get_drvdata(pdev); | |
208 | ||
209 | unregister_framebuffer(info); | |
210 | framebuffer_release(info); | |
211 | ||
212 | return 0; | |
213 | } | |
214 | ||
215 | static const struct of_device_id simplefb_of_match[] = { | |
216 | { .compatible = "simple-framebuffer", }, | |
217 | { }, | |
218 | }; | |
219 | MODULE_DEVICE_TABLE(of, simplefb_of_match); | |
220 | ||
221 | static struct platform_driver simplefb_driver = { | |
222 | .driver = { | |
223 | .name = "simple-framebuffer", | |
224 | .owner = THIS_MODULE, | |
225 | .of_match_table = simplefb_of_match, | |
226 | }, | |
227 | .probe = simplefb_probe, | |
228 | .remove = simplefb_remove, | |
229 | }; | |
230 | module_platform_driver(simplefb_driver); | |
231 | ||
232 | MODULE_AUTHOR("Stephen Warren <swarren@wwwdotorg.org>"); | |
233 | MODULE_DESCRIPTION("Simple framebuffer driver"); | |
234 | MODULE_LICENSE("GPL v2"); |