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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/firmware/sysfb.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/firmware/sysfb.c')
-rw-r--r--drivers/firmware/sysfb.c225
1 files changed, 225 insertions, 0 deletions
diff --git a/drivers/firmware/sysfb.c b/drivers/firmware/sysfb.c
new file mode 100644
index 000000000..8833582c1
--- /dev/null
+++ b/drivers/firmware/sysfb.c
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Generic System Framebuffers
+ * Copyright (c) 2012-2013 David Herrmann <dh.herrmann@gmail.com>
+ */
+
+/*
+ * Simple-Framebuffer support
+ * Create a platform-device for any available boot framebuffer. The
+ * simple-framebuffer platform device is already available on DT systems, so
+ * this module parses the global "screen_info" object and creates a suitable
+ * platform device compatible with the "simple-framebuffer" DT object. If
+ * the framebuffer is incompatible, we instead create a legacy
+ * "vesa-framebuffer", "efi-framebuffer" or "platform-framebuffer" device and
+ * pass the screen_info as platform_data. This allows legacy drivers
+ * to pick these devices up without messing with simple-framebuffer drivers.
+ * The global "screen_info" is still valid at all times.
+ *
+ * If CONFIG_SYSFB_SIMPLEFB is not selected, never register "simple-framebuffer"
+ * platform devices, but only use legacy framebuffer devices for
+ * backwards compatibility.
+ *
+ * TODO: We set the dev_id field of all platform-devices to 0. This allows
+ * other OF/DT parsers to create such devices, too. However, they must
+ * start at offset 1 for this to work.
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/pci.h>
+#include <linux/platform_data/simplefb.h>
+#include <linux/platform_device.h>
+#include <linux/screen_info.h>
+#include <linux/sysfb.h>
+
+static struct platform_device *pd;
+static DEFINE_MUTEX(disable_lock);
+static bool disabled;
+
+static struct device *sysfb_parent_dev(const struct screen_info *si);
+
+static bool sysfb_unregister(void)
+{
+ if (IS_ERR_OR_NULL(pd))
+ return false;
+
+ platform_device_unregister(pd);
+ pd = NULL;
+
+ return true;
+}
+
+/**
+ * sysfb_disable() - disable the Generic System Framebuffers support
+ * @dev: the device to check if non-NULL
+ *
+ * This disables the registration of system framebuffer devices that match the
+ * generic drivers that make use of the system framebuffer set up by firmware.
+ *
+ * It also unregisters a device if this was already registered by sysfb_init().
+ *
+ * Context: The function can sleep. A @disable_lock mutex is acquired to serialize
+ * against sysfb_init(), that registers a system framebuffer device.
+ */
+void sysfb_disable(struct device *dev)
+{
+ struct screen_info *si = &sysfb_primary_display.screen;
+ struct device *parent;
+
+ mutex_lock(&disable_lock);
+ parent = sysfb_parent_dev(si);
+ if (!dev || !parent || dev == parent) {
+ sysfb_unregister();
+ disabled = true;
+ }
+ mutex_unlock(&disable_lock);
+}
+EXPORT_SYMBOL_GPL(sysfb_disable);
+
+/**
+ * sysfb_handles_screen_info() - reports if sysfb handles the global screen_info
+ *
+ * Callers can use sysfb_handles_screen_info() to determine whether the Generic
+ * System Framebuffers (sysfb) can handle the global screen_info data structure
+ * or not. Drivers might need this information to know if they have to setup the
+ * system framebuffer, or if they have to delegate this action to sysfb instead.
+ *
+ * Returns:
+ * True if sysfb handles the global screen_info data structure.
+ */
+bool sysfb_handles_screen_info(void)
+{
+ const struct screen_info *si = &sysfb_primary_display.screen;
+
+ return !!screen_info_video_type(si);
+}
+EXPORT_SYMBOL_GPL(sysfb_handles_screen_info);
+
+#if defined(CONFIG_PCI)
+static bool sysfb_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;
+}
+#else
+static bool sysfb_pci_dev_is_enabled(struct pci_dev *pdev)
+{
+ return false;
+}
+#endif
+
+static struct device *sysfb_parent_dev(const struct screen_info *si)
+{
+ struct pci_dev *pdev;
+
+ pdev = screen_info_pci_dev(si);
+ if (IS_ERR(pdev)) {
+ return ERR_CAST(pdev);
+ } else if (pdev) {
+ if (!sysfb_pci_dev_is_enabled(pdev)) {
+ pci_dev_put(pdev);
+ return ERR_PTR(-ENODEV);
+ }
+ return &pdev->dev;
+ }
+
+ return NULL;
+}
+
+static __init int sysfb_init(void)
+{
+ struct sysfb_display_info *dpy = &sysfb_primary_display;
+ struct screen_info *si = &dpy->screen;
+ struct device *parent;
+ unsigned int type;
+ struct simplefb_platform_data mode;
+ const char *name;
+ bool compatible;
+ int ret = 0;
+
+ screen_info_apply_fixups();
+
+ mutex_lock(&disable_lock);
+ if (disabled)
+ goto unlock_mutex;
+
+ sysfb_apply_efi_quirks(si);
+
+ parent = sysfb_parent_dev(si);
+ if (IS_ERR(parent)) {
+ ret = PTR_ERR(parent);
+ goto unlock_mutex;
+ }
+
+ /* try to create a simple-framebuffer device */
+ compatible = sysfb_parse_mode(si, &mode);
+ if (compatible) {
+ pd = sysfb_create_simplefb(si, &mode, parent);
+ if (!IS_ERR(pd))
+ goto put_device;
+ }
+
+ type = screen_info_video_type(si);
+
+ /* if the FB is incompatible, create a legacy framebuffer device */
+ switch (type) {
+ case VIDEO_TYPE_EGAC:
+ name = "ega-framebuffer";
+ break;
+ case VIDEO_TYPE_VGAC:
+ name = "vga-framebuffer";
+ break;
+ case VIDEO_TYPE_VLFB:
+ name = "vesa-framebuffer";
+ break;
+ case VIDEO_TYPE_EFI:
+ name = "efi-framebuffer";
+ break;
+ default:
+ name = "platform-framebuffer";
+ break;
+ }
+
+ pd = platform_device_alloc(name, 0);
+ if (!pd) {
+ ret = -ENOMEM;
+ goto put_device;
+ }
+
+ pd->dev.parent = parent;
+
+ sysfb_set_efifb_fwnode(si, pd);
+
+ ret = platform_device_add_data(pd, dpy, sizeof(*dpy));
+ if (ret)
+ goto err;
+
+ ret = platform_device_add(pd);
+ if (ret)
+ goto err;
+
+ goto put_device;
+err:
+ platform_device_put(pd);
+put_device:
+ put_device(parent);
+unlock_mutex:
+ mutex_unlock(&disable_lock);
+ return ret;
+}
+
+/* must execute after PCI subsystem for EFI quirks */
+device_initcall(sysfb_init);