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authorThomas Zimmermann <tzimmermann@suse.de>2024-02-12 12:06:10 +0300
committerThomas Zimmermann <tzimmermann@suse.de>2024-02-14 12:09:16 +0300
commit036105e3a776b6fc2fe0d262896a23ff2cc2e6b1 (patch)
tree2849d117a6ab8067abc637f14721a728ee839d26 /drivers/video
parent75fa9b7e375e35739663cde0252d31e586c6314a (diff)
downloadlinux-036105e3a776b6fc2fe0d262896a23ff2cc2e6b1.tar.xz
video: Provide screen_info_get_pci_dev() to find screen_info's PCI device
Add screen_info_get_pci_dev() to find the PCI device of an instance of screen_info. Does nothing on systems without PCI bus. v3: * search PCI device with pci_get_base_class() (Sui) v2: * remove ret from screen_info_pci_dev() (Javier) Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20240212090736.11464-3-tzimmermann@suse.de
Diffstat (limited to 'drivers/video')
-rw-r--r--drivers/video/Makefile1
-rw-r--r--drivers/video/screen_info_pci.c48
2 files changed, 49 insertions, 0 deletions
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index 117cbdbb58c2..ffbac4387c67 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_VIDEO) += cmdline.o nomodeset.o
obj-$(CONFIG_HDMI) += hdmi.o
screen_info-y := screen_info_generic.o
+screen_info-$(CONFIG_PCI) += screen_info_pci.o
obj-$(CONFIG_VT) += console/
obj-$(CONFIG_FB_STI) += console/
diff --git a/drivers/video/screen_info_pci.c b/drivers/video/screen_info_pci.c
new file mode 100644
index 000000000000..d8985a54ce71
--- /dev/null
+++ b/drivers/video/screen_info_pci.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/pci.h>
+#include <linux/screen_info.h>
+
+static struct pci_dev *__screen_info_pci_dev(struct resource *res)
+{
+ struct pci_dev *pdev = NULL;
+ const struct resource *r = NULL;
+
+ if (!(res->flags & IORESOURCE_MEM))
+ return NULL;
+
+ while (!r && (pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev))) {
+ r = pci_find_resource(pdev, res);
+ }
+
+ return pdev;
+}
+
+/**
+ * screen_info_pci_dev() - Return PCI parent device that contains screen_info's framebuffer
+ * @si: the screen_info
+ *
+ * Returns:
+ * The screen_info's parent device or NULL on success, or a pointer-encoded
+ * errno value otherwise. The value NULL is not an error. It signals that no
+ * PCI device has been found.
+ */
+struct pci_dev *screen_info_pci_dev(const struct screen_info *si)
+{
+ struct resource res[SCREEN_INFO_MAX_RESOURCES];
+ ssize_t i, numres;
+
+ numres = screen_info_resources(si, res, ARRAY_SIZE(res));
+ if (numres < 0)
+ return ERR_PTR(numres);
+
+ for (i = 0; i < numres; ++i) {
+ struct pci_dev *pdev = __screen_info_pci_dev(&res[i]);
+
+ if (pdev)
+ return pdev;
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL(screen_info_pci_dev);