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// SPDX-License-Identifier: GPL-2.0-only
/*
* 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
*/
#include <common.h>
#include <fb.h>
#include <io.h>
#include <linux/platform_data/simplefb.h>
#include <driver.h>
#include <of.h>
static struct fb_ops simplefb_ops;
static struct simplefb_format simplefb_formats[] = SIMPLEFB_FORMATS;
struct simplefb_params {
u32 width;
u32 height;
u32 stride;
struct simplefb_format *format;
};
struct simplefb {
struct fb_info info;
struct fb_videomode mode;
};
static int simplefb_parse_dt(struct device *dev,
struct simplefb_params *params)
{
struct device_node *np = dev->of_node;
int ret;
const char *format;
int i;
ret = of_property_read_u32(np, "width", ¶ms->width);
if (ret) {
dev_err(dev, "Can't parse width property\n");
return ret;
}
ret = of_property_read_u32(np, "height", ¶ms->height);
if (ret) {
dev_err(dev, "Can't parse height property\n");
return ret;
}
ret = of_property_read_u32(np, "stride", ¶ms->stride);
if (ret) {
dev_err(dev, "Can't parse stride property\n");
return ret;
}
ret = of_property_read_string(np, "format", &format);
if (ret) {
dev_err(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(dev, "Invalid format value\n");
return -EINVAL;
}
return 0;
}
static int simplefb_probe(struct device *dev)
{
int ret;
struct simplefb_params params;
struct simplefb *simplefb;
struct fb_info *info;
struct resource *mem;
ret = -ENODEV;
if (dev->of_node)
ret = simplefb_parse_dt(dev, ¶ms);
if (ret)
return ret;
mem = dev_request_mem_resource(dev, 0);
if (IS_ERR(mem)) {
dev_err(dev, "No memory resource\n");
return PTR_ERR(mem);
}
simplefb = xzalloc(sizeof(*simplefb));
simplefb->mode.name = params.format->name;
simplefb->mode.xres = params.width;
simplefb->mode.yres = params.height;
info = &simplefb->info;
info->mode = &simplefb->mode;
info->bits_per_pixel = params.format->bits_per_pixel;
info->red = params.format->red;
info->green = params.format->green;
info->blue = params.format->blue;
info->transp = params.format->transp;
info->screen_base = (void *)mem->start;
info->screen_size = resource_size(mem);
info->fbops = &simplefb_ops;
info->dev.parent = dev;
ret = register_framebuffer(info);
if (ret < 0) {
dev_err(dev, "Unable to register simplefb: %d\n", ret);
return ret;
}
dev_info(dev, "size %s registered\n", size_human_readable(info->screen_size));
return 0;
}
static const struct of_device_id simplefb_of_match[] = {
{ .compatible = "simple-framebuffer", },
{ },
};
MODULE_DEVICE_TABLE(of, simplefb_of_match);
static struct driver simplefb_driver = {
.name = "simple-framebuffer",
.of_compatible = simplefb_of_match,
.probe = simplefb_probe,
};
device_platform_driver(simplefb_driver);
MODULE_AUTHOR("Stephen Warren <swarren@wwwdotorg.org>");
MODULE_DESCRIPTION("Simple framebuffer driver");
MODULE_LICENSE("GPL v2");
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