Register a simplefb framebuffer when the coreboot table contains a framebuffer entry.
Signed-off-by: Samuel Holland samuel@sholland.org --- drivers/firmware/google/Kconfig | 8 ++ drivers/firmware/google/Makefile | 1 + drivers/firmware/google/coreboot_table.h | 22 +++++ drivers/firmware/google/framebuffer-coreboot.c | 115 +++++++++++++++++++++++++ 4 files changed, 146 insertions(+) create mode 100644 drivers/firmware/google/framebuffer-coreboot.c
diff --git a/drivers/firmware/google/Kconfig b/drivers/firmware/google/Kconfig index f16b381a569c..a456a000048b 100644 --- a/drivers/firmware/google/Kconfig +++ b/drivers/firmware/google/Kconfig @@ -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 diff --git a/drivers/firmware/google/Makefile b/drivers/firmware/google/Makefile index dcd3675efcfc..d0b3fba96194 100644 --- a/drivers/firmware/google/Makefile +++ b/drivers/firmware/google/Makefile @@ -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 diff --git a/drivers/firmware/google/coreboot_table.h b/drivers/firmware/google/coreboot_table.h index 26a3f3f3ac9c..8ad95a94481b 100644 --- a/drivers/firmware/google/coreboot_table.h +++ b/drivers/firmware/google/coreboot_table.h @@ -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; }; };
diff --git a/drivers/firmware/google/framebuffer-coreboot.c b/drivers/firmware/google/framebuffer-coreboot.c new file mode 100644 index 000000000000..b8b49c067157 --- /dev/null +++ b/drivers/firmware/google/framebuffer-coreboot.c @@ -0,0 +1,115 @@ +/* + * 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");