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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188// 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/device-id/coreboot.h>#include <linux/module.h>#include <linux/pci.h>#include <linux/platform_data/simplefb.h>#include <linux/platform_device.h>#include <linux/sysfb.h>
#include "coreboot_table.h"
#if defined(CONFIG_PCI)static bool framebuffer_pci_dev_is_enabled(struct pci_dev *pdev){ /* * TODO: Try to integrate this code into the PCI subsystem */ int ret; u16 command;
ret = pci_read_config_word(pdev, PCI_COMMAND, &command); if (ret != PCIBIOS_SUCCESSFUL) return false; if (!(command & PCI_COMMAND_MEMORY)) return false; return true;}
static struct pci_dev *framebuffer_parent_pci_dev(struct resource *res){ struct pci_dev *pdev = NULL; const struct resource *r = NULL;
while (!r && (pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev))) r = pci_find_resource(pdev, res);
if (!r || !pdev) return NULL; /* not found; not an error */
if (!framebuffer_pci_dev_is_enabled(pdev)) { pci_dev_put(pdev); return ERR_PTR(-ENODEV); }
return pdev;}#elsestatic struct pci_dev *framebuffer_parent_pci_dev(struct resource *res){ return NULL;}#endif
static struct device *framebuffer_parent_dev(struct resource *res){ struct pci_dev *pdev;
pdev = framebuffer_parent_pci_dev(res); if (IS_ERR(pdev)) return ERR_CAST(pdev); else if (pdev) return &pdev->dev;
return NULL;}
static int framebuffer_probe(struct coreboot_device *dev){ struct lb_framebuffer *fb = &dev->framebuffer; struct device *parent; struct platform_device *pdev; struct resource res; int ret;#if !IS_ENABLED(CONFIG_DRM_COREBOOTDRM) struct simplefb_platform_data pdata = { .width = fb->x_resolution, .height = fb->y_resolution, .stride = fb->bytes_per_line, .format = NULL, }; int i; static const struct simplefb_format formats[] = SIMPLEFB_FORMATS;#endif
/* * On coreboot systems, the advertised LB_TAG_FRAMEBUFFER entry * in the coreboot table should only be used if the payload did * not pass a framebuffer information to the Linux kernel. * * If the global screen_info data has been filled, the Generic * System Framebuffers (sysfb) will already register a platform * device and pass that screen_info as platform_data to a driver * that can scan-out using the system provided framebuffer. */ if (sysfb_handles_screen_info()) return -ENODEV;
if (!fb->physical_address) return -ENODEV;
res = DEFINE_RES_MEM(fb->physical_address, PAGE_ALIGN(fb->y_resolution * fb->bytes_per_line)); if (res.end <= res.start) return -EINVAL;
parent = framebuffer_parent_dev(&res); if (IS_ERR(parent)) return PTR_ERR(parent);
#if IS_ENABLED(CONFIG_DRM_COREBOOTDRM) pdev = platform_device_register_resndata(parent, "coreboot-framebuffer", 0, &res, 1, fb, fb->size); if (IS_ERR(pdev)) { pr_warn("coreboot: could not register framebuffer\n"); ret = PTR_ERR(pdev); goto out_put_device_parent; }#else /* * FIXME: Coreboot systems should use a driver that binds to * coreboot-framebuffer devices. Remove support for * simple-framebuffer at some point. */ 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) { ret = -ENODEV; goto out_put_device_parent; }
pdev = platform_device_register_resndata(parent, "simple-framebuffer", 0, &res, 1, &pdata, sizeof(pdata)); if (IS_ERR(pdev)) { ret = PTR_ERR(pdev); pr_warn("coreboot: could not register framebuffer\n"); goto out_put_device_parent; }#endif
ret = 0;
out_put_device_parent: if (parent) put_device(parent); return ret;}
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, .drv = { .name = "framebuffer", }, .id_table = framebuffer_ids,};module_coreboot_driver(framebuffer_driver);
MODULE_AUTHOR("Samuel Holland <samuel@sholland.org>");MODULE_DESCRIPTION("Memory based framebuffer accessed through coreboot table");MODULE_LICENSE("GPL");