From:   Javier Martinez Canillas <javierm@redhat.com>
To:     linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org
Cc:     Javier Martinez Canillas <javierm@redhat.com>,
        Thomas Zimmermann <tzimmermann@suse.de>
Subject: [PATCH v2 01/37] drm: Add drm_module_{pci,platform}_driver() helper macros
Date:   Fri, 17 Dec 2021 01:37:16 +0100
Message-Id: <20211217003752.3946210-2-javierm@redhat.com>
In-Reply-To: <20211217003752.3946210-1-javierm@redhat.com>
References: <20211217003752.3946210-1-javierm@redhat.com>
MIME-Version: 1.0
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According to disable Documentation/admin-guide/kernel-parameters.txt, the
nomodeset parameter can be used to disable kernel modesetting.

DRM drivers will not perform display-mode changes or accelerated rendering
and only the system framebuffer will be available if it was set-up.

But only a few DRM drivers currently check for nomodeset, so let's add two
helper macros that can be used by DRM drivers for PCI and platform devices
to have module init functions that checks if the drivers could be loaded.

Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
---

(no changes since v1)

 include/drm/drm_drv.h | 50 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index f6159acb8856..4001d73428c5 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -29,6 +29,8 @@
 
 #include <linux/list.h>
 #include <linux/irqreturn.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
 
 #include <drm/drm_device.h>
 
@@ -604,4 +606,52 @@ int drm_dev_set_unique(struct drm_device *dev, const char *name);
 
 extern bool drm_firmware_drivers_only(void);
 
+/**
+ * drm_pci_register_driver() - register a DRM driver for PCI devices
+ * @drv: PCI driver structure
+ *
+ * Returns zero on success or a negative errno code on failure.
+ */
+static inline int drm_pci_register_driver(struct pci_driver *drv)
+{
+	if (drm_firmware_drivers_only())
+		return -ENODEV;
+
+	return pci_register_driver(drv);
+}
+
+/**
+ * drm_module_pci_driver() - helper macro for registering a DRM PCI driver
+ *
+ * Helper macro for DRM PCI drivers which do not do anything special in their
+ * module init/exit and just need the DRM specific module init.
+ */
+#define drm_module_pci_driver(__pci_driver) \
+	module_driver(__pci_driver, drm_pci_register_driver, \
+		      pci_unregister_driver)
+
+/**
+ * drm_platform_driver_register - register a DRM driver for platform devices
+ * @drv: platform driver structure
+ *
+ * Returns zero on success or a negative errno code on failure.
+ */
+static inline int drm_platform_driver_register(struct platform_driver *drv)
+{
+	if (drm_firmware_drivers_only())
+		return -ENODEV;
+
+	return platform_driver_register(drv);
+}
+
+/**
+ * drm_module_platform_driver() - helper macro for registering a DRM platform driver
+ *
+ * Helper macro for DRM platform drivers which do not do anything special in their
+ * module init/exit and just need the DRM specific module init.
+ */
+#define drm_module_platform_driver(__platform_driver) \
+	module_driver(__platform_driver, drm_platform_driver_register, \
+		      platform_driver_unregister)
+
 #endif
-- 
2.33.1