firmware: coreboot: Add coreboot framebuffer driver (851b4c14) · Commits · EulixOS / Software / Kernel

drivers/firmware/google/Kconfig

+8 −0

Original line number	Diff line number	Diff line
		@@ -55,6 +55,14 @@ config GOOGLE_MEMCONSOLE_X86_LEGACY
		the EBDA on Google servers. If found, this log is exported to
		userland in the file /sys/firmware/log.

		config GOOGLE_FRAMEBUFFER_COREBOOT
		tristate "Coreboot Framebuffer"
		depends on FB_SIMPLE
		depends on GOOGLE_COREBOOT_TABLE
		help
		This option enables the kernel to search for a framebuffer in
		the coreboot table. If found, it is registered with simplefb.

		config GOOGLE_MEMCONSOLE_COREBOOT
		tristate "Firmware Memory Console"
		depends on GOOGLE_COREBOOT_TABLE

drivers/firmware/google/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -4,6 +4,7 @@ obj-$(CONFIG_GOOGLE_SMI) += gsmi.o
		obj-$(CONFIG_GOOGLE_COREBOOT_TABLE) += coreboot_table.o
		obj-$(CONFIG_GOOGLE_COREBOOT_TABLE_ACPI) += coreboot_table-acpi.o
		obj-$(CONFIG_GOOGLE_COREBOOT_TABLE_OF) += coreboot_table-of.o
		obj-$(CONFIG_GOOGLE_FRAMEBUFFER_COREBOOT) += framebuffer-coreboot.o
		obj-$(CONFIG_GOOGLE_MEMCONSOLE) += memconsole.o
		obj-$(CONFIG_GOOGLE_MEMCONSOLE_COREBOOT) += memconsole-coreboot.o
		obj-$(CONFIG_GOOGLE_MEMCONSOLE_X86_LEGACY) += memconsole-x86-legacy.o

drivers/firmware/google/coreboot_table.h

+22 −0

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		@@ -3,6 +3,7 @@
		*
		* Internal header for coreboot table access.
		*
		* Copyright 2014 Gerd Hoffmann <kraxel@redhat.com>
		* Copyright 2017 Google Inc.
		* Copyright 2017 Samuel Holland <samuel@sholland.org>
		*
		@@ -46,12 +47,33 @@ struct lb_cbmem_ref {
		u64 cbmem_addr;
		};

		/* Describes framebuffer setup by coreboot */
		struct lb_framebuffer {
		u32 tag;
		u32 size;

		u64 physical_address;
		u32 x_resolution;
		u32 y_resolution;
		u32 bytes_per_line;
		u8 bits_per_pixel;
		u8 red_mask_pos;
		u8 red_mask_size;
		u8 green_mask_pos;
		u8 green_mask_size;
		u8 blue_mask_pos;
		u8 blue_mask_size;
		u8 reserved_mask_pos;
		u8 reserved_mask_size;
		};

		/* A device, additionally with information from coreboot. */
		struct coreboot_device {
		struct device dev;
		union {
		struct coreboot_table_entry entry;
		struct lb_cbmem_ref cbmem_ref;
		struct lb_framebuffer framebuffer;
		};
		};

drivers/firmware/google/framebuffer-coreboot.c

0 → 100644

+115 −0

Original line number	Diff line number	Diff line
		/*
		* 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>
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License v2.0 as published by
		* the Free Software Foundation.
		*
		* This program is distributed in the hope that 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/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,
		};

		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 &&
		fb->reserved_mask_pos == formats[i].transp.offset &&
		fb->reserved_mask_size == formats[i].transp.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 int framebuffer_remove(struct coreboot_device *dev)
		{
		struct platform_device *pdev = dev_get_drvdata(&dev->dev);

		platform_device_unregister(pdev);

		return 0;
		}

		static struct coreboot_driver framebuffer_driver = {
		.probe = framebuffer_probe,
		.remove = framebuffer_remove,
		.drv = {
		.name = "framebuffer",
		},
		.tag = CB_TAG_FRAMEBUFFER,
		};

		static int __init coreboot_framebuffer_init(void)
		{
		return coreboot_driver_register(&framebuffer_driver);
		}

		static void coreboot_framebuffer_exit(void)
		{
		coreboot_driver_unregister(&framebuffer_driver);
		}

		module_init(coreboot_framebuffer_init);
		module_exit(coreboot_framebuffer_exit);

		MODULE_AUTHOR("Samuel Holland <samuel@sholland.org>");
		MODULE_LICENSE("GPL");