--- /dev/null
+/*
+ * Simplest possible simple frame-buffer driver, as a platform device
+ *
+ * Copyright (c) 2013, Stephen Warren
+ *
+ * Based on q40fb.c, which was:
+ * Copyright (C) 2001 Richard Zidlicky <rz@linux-m68k.org>
+ *
+ * Also based on offb.c, which was:
+ * Copyright (C) 1997 Geert Uytterhoeven
+ * Copyright (C) 1996 Paul Mackerras
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/errno.h>
+#include <linux/fb.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+static struct fb_fix_screeninfo simplefb_fix = {
+ .id = "simple",
+ .type = FB_TYPE_PACKED_PIXELS,
+ .visual = FB_VISUAL_TRUECOLOR,
+ .accel = FB_ACCEL_NONE,
+};
+
+static struct fb_var_screeninfo simplefb_var = {
+ .height = -1,
+ .width = -1,
+ .activate = FB_ACTIVATE_NOW,
+ .vmode = FB_VMODE_NONINTERLACED,
+};
+
+static int simplefb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
+ u_int transp, struct fb_info *info)
+{
+ u32 *pal = info->pseudo_palette;
+ u32 cr = red >> (16 - info->var.red.length);
+ u32 cg = green >> (16 - info->var.green.length);
+ u32 cb = blue >> (16 - info->var.blue.length);
+ u32 value;
+
+ if (regno >= 16)
+ return -EINVAL;
+
+ value = (cr << info->var.red.offset) |
+ (cg << info->var.green.offset) |
+ (cb << info->var.blue.offset);
+ if (info->var.transp.length > 0) {
+ u32 mask = (1 << info->var.transp.length) - 1;
+ mask <<= info->var.transp.offset;
+ value |= mask;
+ }
+ pal[regno] = value;
+
+ return 0;
+}
+
+static struct fb_ops simplefb_ops = {
+ .owner = THIS_MODULE,
+ .fb_setcolreg = simplefb_setcolreg,
+ .fb_fillrect = cfb_fillrect,
+ .fb_copyarea = cfb_copyarea,
+ .fb_imageblit = cfb_imageblit,
+};
+
+struct simplefb_format {
+ const char *name;
+ u32 bits_per_pixel;
+ struct fb_bitfield red;
+ struct fb_bitfield green;
+ struct fb_bitfield blue;
+ struct fb_bitfield transp;
+};
+
+static struct simplefb_format simplefb_formats[] = {
+ { "r5g6b5", 16, {11, 5}, {5, 6}, {0, 5}, {0, 0} },
+};
+
+struct simplefb_params {
+ u32 width;
+ u32 height;
+ u32 stride;
+ struct simplefb_format *format;
+};
+
+static int simplefb_parse_dt(struct platform_device *pdev,
+ struct simplefb_params *params)
+{
+ struct device_node *np = pdev->dev.of_node;
+ int ret;
+ const char *format;
+ int i;
+
+ ret = of_property_read_u32(np, "width", ¶ms->width);
+ if (ret) {
+ dev_err(&pdev->dev, "Can't parse width property\n");
+ return ret;
+ }
+
+ ret = of_property_read_u32(np, "height", ¶ms->height);
+ if (ret) {
+ dev_err(&pdev->dev, "Can't parse height property\n");
+ return ret;
+ }
+
+ ret = of_property_read_u32(np, "stride", ¶ms->stride);
+ if (ret) {
+ dev_err(&pdev->dev, "Can't parse stride property\n");
+ return ret;
+ }
+
+ ret = of_property_read_string(np, "format", &format);
+ if (ret) {
+ dev_err(&pdev->dev, "Can't parse format property\n");
+ return ret;
+ }
+ params->format = NULL;
+ for (i = 0; i < ARRAY_SIZE(simplefb_formats); i++) {
+ if (strcmp(format, simplefb_formats[i].name))
+ continue;
+ params->format = &simplefb_formats[i];
+ break;
+ }
+ if (!params->format) {
+ dev_err(&pdev->dev, "Invalid format value\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int simplefb_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct simplefb_params params;
+ struct fb_info *info;
+ struct resource *mem;
+
+ if (fb_get_options("simplefb", NULL))
+ return -ENODEV;
+
+ ret = simplefb_parse_dt(pdev, ¶ms);
+ if (ret)
+ return ret;
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!mem) {
+ dev_err(&pdev->dev, "No memory resource\n");
+ return -EINVAL;
+ }
+
+ info = framebuffer_alloc(sizeof(u32) * 16, &pdev->dev);
+ if (!info)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, info);
+
+ info->fix = simplefb_fix;
+ info->fix.smem_start = mem->start;
+ info->fix.smem_len = resource_size(mem);
+ info->fix.line_length = params.stride;
+
+ info->var = simplefb_var;
+ info->var.xres = params.width;
+ info->var.yres = params.height;
+ info->var.xres_virtual = params.width;
+ info->var.yres_virtual = params.height;
+ info->var.bits_per_pixel = params.format->bits_per_pixel;
+ info->var.red = params.format->red;
+ info->var.green = params.format->green;
+ info->var.blue = params.format->blue;
+ info->var.transp = params.format->transp;
+
+ info->fbops = &simplefb_ops;
+ info->flags = FBINFO_DEFAULT;
+ info->screen_base = devm_ioremap(&pdev->dev, info->fix.smem_start,
+ info->fix.smem_len);
+ if (!info->screen_base) {
+ framebuffer_release(info);
+ return -ENODEV;
+ }
+ info->pseudo_palette = (void *)(info + 1);
+
+ ret = register_framebuffer(info);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Unable to register simplefb: %d\n", ret);
+ framebuffer_release(info);
+ return ret;
+ }
+
+ dev_info(&pdev->dev, "fb%d: simplefb registered!\n", info->node);
+
+ return 0;
+}
+
+static int simplefb_remove(struct platform_device *pdev)
+{
+ struct fb_info *info = platform_get_drvdata(pdev);
+
+ unregister_framebuffer(info);
+ framebuffer_release(info);
+
+ return 0;
+}
+
+static const struct of_device_id simplefb_of_match[] = {
+ { .compatible = "simple-framebuffer", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, simplefb_of_match);
+
+static struct platform_driver simplefb_driver = {
+ .driver = {
+ .name = "simple-framebuffer",
+ .owner = THIS_MODULE,
+ .of_match_table = simplefb_of_match,
+ },
+ .probe = simplefb_probe,
+ .remove = simplefb_remove,
+};
+module_platform_driver(simplefb_driver);
+
+MODULE_AUTHOR("Stephen Warren <swarren@wwwdotorg.org>");
+MODULE_DESCRIPTION("Simple framebuffer driver");
+MODULE_LICENSE("GPL v2");
projects / mirror_ubuntu-disco-kernel.git / commitdiff