102 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * framebuffer-coreboot.c4 *5 * Memory based framebuffer accessed through coreboot table.6 *7 * Copyright 2012-2013 David Herrmann <dh.herrmann@gmail.com>8 * Copyright 2017 Google Inc.9 * Copyright 2017 Samuel Holland <samuel@sholland.org>10 */11 12#include <linux/device.h>13#include <linux/kernel.h>14#include <linux/mm.h>15#include <linux/module.h>16#include <linux/platform_data/simplefb.h>17#include <linux/platform_device.h>18 19#include "coreboot_table.h"20 21#define CB_TAG_FRAMEBUFFER 0x1222 23static const struct simplefb_format formats[] = SIMPLEFB_FORMATS;24 25static int framebuffer_probe(struct coreboot_device *dev)26{27 int i;28 u32 length;29 struct lb_framebuffer *fb = &dev->framebuffer;30 struct platform_device *pdev;31 struct resource res;32 struct simplefb_platform_data pdata = {33 .width = fb->x_resolution,34 .height = fb->y_resolution,35 .stride = fb->bytes_per_line,36 .format = NULL,37 };38 39 if (!fb->physical_address)40 return -ENODEV;41 42 for (i = 0; i < ARRAY_SIZE(formats); ++i) {43 if (fb->bits_per_pixel == formats[i].bits_per_pixel &&44 fb->red_mask_pos == formats[i].red.offset &&45 fb->red_mask_size == formats[i].red.length &&46 fb->green_mask_pos == formats[i].green.offset &&47 fb->green_mask_size == formats[i].green.length &&48 fb->blue_mask_pos == formats[i].blue.offset &&49 fb->blue_mask_size == formats[i].blue.length)50 pdata.format = formats[i].name;51 }52 if (!pdata.format)53 return -ENODEV;54 55 memset(&res, 0, sizeof(res));56 res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;57 res.name = "Coreboot Framebuffer";58 res.start = fb->physical_address;59 length = PAGE_ALIGN(fb->y_resolution * fb->bytes_per_line);60 res.end = res.start + length - 1;61 if (res.end <= res.start)62 return -EINVAL;63 64 pdev = platform_device_register_resndata(&dev->dev,65 "simple-framebuffer", 0,66 &res, 1, &pdata,67 sizeof(pdata));68 if (IS_ERR(pdev))69 pr_warn("coreboot: could not register framebuffer\n");70 else71 dev_set_drvdata(&dev->dev, pdev);72 73 return PTR_ERR_OR_ZERO(pdev);74}75 76static void framebuffer_remove(struct coreboot_device *dev)77{78 struct platform_device *pdev = dev_get_drvdata(&dev->dev);79 80 platform_device_unregister(pdev);81}82 83static const struct coreboot_device_id framebuffer_ids[] = {84 { .tag = CB_TAG_FRAMEBUFFER },85 { /* sentinel */ }86};87MODULE_DEVICE_TABLE(coreboot, framebuffer_ids);88 89static struct coreboot_driver framebuffer_driver = {90 .probe = framebuffer_probe,91 .remove = framebuffer_remove,92 .drv = {93 .name = "framebuffer",94 },95 .id_table = framebuffer_ids,96};97module_coreboot_driver(framebuffer_driver);98 99MODULE_AUTHOR("Samuel Holland <samuel@sholland.org>");100MODULE_DESCRIPTION("Memory based framebuffer accessed through coreboot table");101MODULE_LICENSE("GPL");102