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// SPDX-License-Identifier: GPL-2.0-only
/*
* framebuffer-coreboot.c
*
* Memory based framebuffer accessed through coreboot table.
*
* Copyright 2012-2013 David Herrmann <dh.herrmann@gmail.com>
* Copyright 2017 Google Inc.
* Copyright 2017 Samuel Holland <samuel@sholland.org>
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/platform_data/simplefb.h>
#include <linux/platform_device.h>
#include "coreboot_table.h"
#define CB_TAG_FRAMEBUFFER 0x12
static const struct simplefb_format formats[] = SIMPLEFB_FORMATS;
static int framebuffer_probe(struct coreboot_device *dev)
{
int i;
u32 length;
struct lb_framebuffer *fb = &dev->framebuffer;
struct platform_device *pdev;
struct resource res;
struct simplefb_platform_data pdata = {
.width = fb->x_resolution,
.height = fb->y_resolution,
.stride = fb->bytes_per_line,
.format = NULL,
};
if (!fb->physical_address)
return -ENODEV;
for (i = 0; i < ARRAY_SIZE(formats); ++i) {
if (fb->bits_per_pixel == formats[i].bits_per_pixel &&
fb->red_mask_pos == formats[i].red.offset &&
fb->red_mask_size == formats[i].red.length &&
fb->green_mask_pos == formats[i].green.offset &&
fb->green_mask_size == formats[i].green.length &&
fb->blue_mask_pos == formats[i].blue.offset &&
fb->blue_mask_size == formats[i].blue.length)
pdata.format = formats[i].name;
}
if (!pdata.format)
return -ENODEV;
memset(&res, 0, sizeof(res));
res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
res.name = "Coreboot Framebuffer";
res.start = fb->physical_address;
length = PAGE_ALIGN(fb->y_resolution * fb->bytes_per_line);
res.end = res.start + length - 1;
if (res.end <= res.start)
return -EINVAL;
pdev = platform_device_register_resndata(&dev->dev,
"simple-framebuffer", 0,
&res, 1, &pdata,
sizeof(pdata));
if (IS_ERR(pdev))
pr_warn("coreboot: could not register framebuffer\n");
else
dev_set_drvdata(&dev->dev, pdev);
return PTR_ERR_OR_ZERO(pdev);
}
static void framebuffer_remove(struct coreboot_device *dev)
{
struct platform_device *pdev = dev_get_drvdata(&dev->dev);
platform_device_unregister(pdev);
}
static const struct coreboot_device_id framebuffer_ids[] = {
{ .tag = CB_TAG_FRAMEBUFFER },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(coreboot, framebuffer_ids);
static struct coreboot_driver framebuffer_driver = {
.probe = framebuffer_probe,
.remove = framebuffer_remove,
.drv = {
.name = "framebuffer",
},
.id_table = framebuffer_ids,
};
module_coreboot_driver(framebuffer_driver);
MODULE_AUTHOR("Samuel Holland <samuel@sholland.org>");
MODULE_LICENSE("GPL");
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