ACPI video: if no ACPI backlight support, use vendor drivers
authorThomas Renninger <trenn@suse.de>
Fri, 1 Aug 2008 15:37:55 +0000 (17:37 +0200)
committerLen Brown <len.brown@intel.com>
Sat, 8 Nov 2008 04:57:55 +0000 (23:57 -0500)
If an ACPI graphics device supports backlight brightness functions (cmp. with
latest ACPI spec Appendix B), let the ACPI video driver control backlight and
switch backlight control off in vendor specific ACPI drivers (asus_acpi,
thinkpad_acpi, eeepc, fujitsu_laptop, msi_laptop, sony_laptop, acer-wmi).

Currently it is possible to load above drivers and let both poke on the
brightness HW registers, the video and vendor specific ACPI drivers -> bad.

This patch provides the basic support to check for BIOS capabilities before
driver loading time. Driver specific modifications are in separate follow up
patches.

"acpi_backlight=vendor"
Prever vendor driver over ACPI driver for backlight.
"acpi_backlight=video" (default)
Prever ACPI driver over vendor driver for backlight.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Documentation/kernel-parameters.txt
drivers/acpi/Makefile
drivers/acpi/scan.c
drivers/acpi/video.c
drivers/acpi/video_detect.c [new file with mode: 0644]
include/linux/acpi.h

index c86c074597129a5b4434b0e35c432a0a28636b11..dd5013f974d8263b937ace38e5e0424bb4aa0617 100644 (file)
@@ -198,6 +198,18 @@ and is between 256 and 4096 characters. It is defined in the file
                        that require a timer override, but don't have
                        HPET
 
+       acpi_backlight= [HW,ACPI]
+                       acpi_backlight=vendor
+                       acpi_backlight=video
+                       If set to vendor, prefer vendor specific driver
+                       (e.g. thinkpad_acpi, sony_acpi, etc.) instead
+                       of the ACPI video.ko driver.
+
+       acpi_display_output=    [HW,ACPI]
+                       acpi_display_output=vendor
+                       acpi_display_output=video
+                       See above.
+
        acpi.debug_layer=       [HW,ACPI]
                        Format: <int>
                        Each bit of the <int> indicates an ACPI debug layer,
index d91c027ece8f6409cc50a83023ac7821a4f9b1a4..c03810aa19c0b46db0a857ff11543fa1eb4ccbc5 100644 (file)
@@ -46,6 +46,10 @@ obj-$(CONFIG_ACPI_BUTTON)    += button.o
 obj-$(CONFIG_ACPI_FAN)         += fan.o
 obj-$(CONFIG_ACPI_DOCK)                += dock.o
 obj-$(CONFIG_ACPI_VIDEO)       += video.o
+ifdef CONFIG_ACPI_VIDEO
+obj-y                          += video_detect.o
+endif
+
 obj-y                          += pci_root.o pci_link.o pci_irq.o pci_bind.o
 obj-$(CONFIG_ACPI_PCI_SLOT)    += pci_slot.o
 obj-$(CONFIG_ACPI_PROCESSOR)   += processor.o
index a9dda8e0f9f9c2c14859b027fcd80b1b88abdeda..556b182001ca331069b240b77b6f970585b56f3f 100644 (file)
@@ -919,36 +919,6 @@ static void acpi_device_get_busid(struct acpi_device *device,
        }
 }
 
-static int
-acpi_video_bus_match(struct acpi_device *device)
-{
-       acpi_handle h_dummy;
-
-       if (!device)
-               return -EINVAL;
-
-       /* Since there is no HID, CID for ACPI Video drivers, we have
-        * to check well known required nodes for each feature we support.
-        */
-
-       /* Does this device able to support video switching ? */
-       if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) &&
-           ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy)))
-               return 0;
-
-       /* Does this device able to retrieve a video ROM ? */
-       if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy)))
-               return 0;
-
-       /* Does this device able to configure which video head to be POSTed ? */
-       if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy)) &&
-           ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy)) &&
-           ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy)))
-               return 0;
-
-       return -ENODEV;
-}
-
 /*
  * acpi_bay_match - see if a device is an ejectable driver bay
  *
@@ -1031,7 +1001,7 @@ static void acpi_device_set_id(struct acpi_device *device,
                   will get autoloaded and the device might still match
                   against another driver.
                */
-               if (ACPI_SUCCESS(acpi_video_bus_match(device)))
+               if (acpi_is_video_device(device))
                        cid_add = ACPI_VIDEO_HID;
                else if (ACPI_SUCCESS(acpi_bay_match(device)))
                        cid_add = ACPI_BAY_HID;
index 6597c2a37c360645bac11987db7074ea63c46686..2097c399dd064a47f81ccc317fe6e9b4e6ac0bfe 100644 (file)
@@ -739,7 +739,8 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
                device->cap._DSS = 1;
        }
 
-       max_level = acpi_video_init_brightness(device);
+       if (acpi_video_backlight_support())
+               max_level = acpi_video_init_brightness(device);
 
        if (device->cap._BCL && device->cap._BCM && max_level > 0) {
                int result;
@@ -785,18 +786,21 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
                        printk(KERN_ERR PREFIX "Create sysfs link\n");
 
        }
-       if (device->cap._DCS && device->cap._DSS){
-               static int count = 0;
-               char *name;
-               name = kzalloc(MAX_NAME_LEN, GFP_KERNEL);
-               if (!name)
-                       return;
-               sprintf(name, "acpi_video%d", count++);
-               device->output_dev = video_output_register(name,
-                               NULL, device, &acpi_output_properties);
-               kfree(name);
+
+       if (acpi_video_display_switch_support()) {
+
+               if (device->cap._DCS && device->cap._DSS) {
+                       static int count;
+                       char *name;
+                       name = kzalloc(MAX_NAME_LEN, GFP_KERNEL);
+                       if (!name)
+                               return;
+                       sprintf(name, "acpi_video%d", count++);
+                       device->output_dev = video_output_register(name,
+                                       NULL, device, &acpi_output_properties);
+                       kfree(name);
+               }
        }
-       return;
 }
 
 /*
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
new file mode 100644 (file)
index 0000000..70b1e91
--- /dev/null
@@ -0,0 +1,268 @@
+/*
+ *  Copyright (C) 2008       SuSE Linux Products GmbH
+ *                           Thomas Renninger <trenn@suse.de>
+ *
+ *  May be copied or modified under the terms of the GNU General Public License
+ *
+ * video_detect.c:
+ * Provides acpi_is_video_device() for early scanning of ACPI devices in scan.c
+ * There a Linux specific (Spec does not provide a HID for video devices) is
+ * assinged
+ *
+ * After PCI devices are glued with ACPI devices
+ * acpi_get_physical_pci_device() can be called to identify ACPI graphics
+ * devices for which a real graphics card is plugged in
+ *
+ * Now acpi_video_get_capabilities() can be called to check which
+ * capabilities the graphics cards plugged in support. The check for general
+ * video capabilities will be triggered by the first caller of
+ * acpi_video_get_capabilities(NULL); which will happen when the first
+ * backlight (or display output) switching supporting driver calls:
+ * acpi_video_backlight_support();
+ *
+ * Depending on whether ACPI graphics extensions (cmp. ACPI spec Appendix B)
+ * are available, video.ko should be used to handle the device.
+ *
+ * Otherwise vendor specific drivers like thinkpad_acpi, asus_acpi,
+ * sony_acpi,... can take care about backlight brightness and display output
+ * switching.
+ *
+ * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m)
+ * this file will not be compiled, acpi_video_get_capabilities() and
+ * acpi_video_backlight_support() will always return 0 and vendor specific
+ * drivers always can handle backlight.
+ *
+ */
+
+#include <linux/acpi.h>
+#include <linux/dmi.h>
+
+ACPI_MODULE_NAME("video");
+#define ACPI_VIDEO_COMPONENT           0x08000000
+#define _COMPONENT             ACPI_VIDEO_COMPONENT
+
+static long acpi_video_support;
+static bool acpi_video_caps_checked;
+
+static acpi_status
+acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
+                         void **retyurn_value)
+{
+       long *cap = context;
+       acpi_handle h_dummy;
+
+       if (ACPI_SUCCESS(acpi_get_handle(handle, "_BCM", &h_dummy)) &&
+           ACPI_SUCCESS(acpi_get_handle(handle, "_BCL", &h_dummy))) {
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
+                                 "support\n"));
+               *cap |= ACPI_VIDEO_BACKLIGHT;
+               /* We have backlight support, no need to scan further */
+               return AE_CTRL_TERMINATE;
+       }
+       return 0;
+}
+
+/* Returns true if the device is a video device which can be handled by
+ * video.ko.
+ * The device will get a Linux specific CID added in scan.c to
+ * identify the device as an ACPI graphics device
+ * Be aware that the graphics device may not be physically present
+ * Use acpi_video_get_capabilities() to detect general ACPI video
+ * capabilities of present cards
+ */
+long acpi_is_video_device(struct acpi_device *device)
+{
+       acpi_handle h_dummy;
+       long video_caps = 0;
+
+       if (!device)
+               return 0;
+
+       /* Does this device able to support video switching ? */
+       if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) &&
+           ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy)))
+               video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
+
+       /* Does this device able to retrieve a video ROM ? */
+       if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy)))
+               video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
+
+       /* Does this device able to configure which video head to be POSTed ? */
+       if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy)) &&
+           ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy)) &&
+           ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy)))
+               video_caps |= ACPI_VIDEO_DEVICE_POSTING;
+
+       /* Only check for backlight functionality if one of the above hit. */
+       if (video_caps)
+               acpi_walk_namespace(ACPI_TYPE_DEVICE, device->handle,
+                                   ACPI_UINT32_MAX, acpi_backlight_cap_match,
+                                   &video_caps, NULL);
+
+       return video_caps;
+}
+EXPORT_SYMBOL(acpi_is_video_device);
+
+static acpi_status
+find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
+{
+       long *cap = context;
+       struct device *dev;
+       struct acpi_device *acpi_dev;
+
+       const struct acpi_device_id video_ids[] = {
+               {ACPI_VIDEO_HID, 0},
+               {"", 0},
+       };
+       if (acpi_bus_get_device(handle, &acpi_dev))
+               return AE_OK;
+
+       if (!acpi_match_device_ids(acpi_dev, video_ids)) {
+               dev = acpi_get_physical_pci_device(handle);
+               if (!dev)
+                       return AE_OK;
+               put_device(dev);
+               *cap |= acpi_is_video_device(acpi_dev);
+       }
+       return AE_OK;
+}
+
+/*
+ * Returns the video capabilities of a specific ACPI graphics device
+ *
+ * if NULL is passed as argument all ACPI devices are enumerated and
+ * all graphics capabilities of physically present devices are
+ * summerized and returned. This is cached and done only once.
+ */
+long acpi_video_get_capabilities(acpi_handle graphics_handle)
+{
+       long caps = 0;
+       struct acpi_device *tmp_dev;
+       acpi_status status;
+
+       if (acpi_video_caps_checked && graphics_handle == NULL)
+               return acpi_video_support;
+
+       if (!graphics_handle) {
+               /* Only do the global walk through all graphics devices once */
+               acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+                                   ACPI_UINT32_MAX, find_video,
+                                   &caps, NULL);
+               /* There might be boot param flags set already... */
+               acpi_video_support |= caps;
+               acpi_video_caps_checked = 1;
+               /* Add blacklists here. Be careful to use the right *DMI* bits
+                * to still be able to override logic via boot params, e.g.:
+                *
+                *   if (dmi_name_in_vendors("XY")) {
+                *      acpi_video_support |=
+                *              ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VENDOR;
+                *      acpi_video_support |=
+                *              ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
+                *}
+                */
+       } else {
+               status = acpi_bus_get_device(graphics_handle, &tmp_dev);
+               if (ACPI_FAILURE(status)) {
+                       ACPI_EXCEPTION((AE_INFO, status, "Invalid device"));
+                       return 0;
+               }
+               acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle,
+                                   ACPI_UINT32_MAX, find_video,
+                                   &caps, NULL);
+       }
+       ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n",
+                         graphics_handle ? caps : acpi_video_support,
+                         graphics_handle ? "on device " : "in general",
+                         graphics_handle ? acpi_device_bid(tmp_dev) : ""));
+       return caps;
+}
+EXPORT_SYMBOL(acpi_video_get_capabilities);
+
+/* Returns true if video.ko can do backlight switching */
+int acpi_video_backlight_support(void)
+{
+       /*
+        * We must check whether the ACPI graphics device is physically plugged
+        * in. Therefore this must be called after binding PCI and ACPI devices
+        */
+       if (!acpi_video_caps_checked)
+               acpi_video_get_capabilities(NULL);
+
+       /* First check for boot param -> highest prio */
+       if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR)
+               return 0;
+       else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO)
+               return 1;
+
+       /* Then check for DMI blacklist -> second highest prio */
+       if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR)
+               return 0;
+       else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO)
+               return 1;
+
+       /* Then go the default way */
+       return acpi_video_support & ACPI_VIDEO_BACKLIGHT;
+}
+EXPORT_SYMBOL(acpi_video_backlight_support);
+
+/*
+ * Returns true if video.ko can do display output switching.
+ * This does not work well/at all with binary graphics drivers
+ * which disable system io ranges and do it on their own.
+ */
+int acpi_video_display_switch_support(void)
+{
+       if (!acpi_video_caps_checked)
+               acpi_video_get_capabilities(NULL);
+
+       if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VENDOR)
+               return 0;
+       else if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VIDEO)
+               return 1;
+
+       if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VENDOR)
+               return 0;
+       else if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VIDEO)
+               return 1;
+
+       return acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING;
+}
+EXPORT_SYMBOL(acpi_video_display_switch_support);
+
+/*
+ * Use acpi_display_output=vendor/video or acpi_backlight=vendor/video
+ * To force that backlight or display output switching is processed by vendor
+ * specific acpi drivers or video.ko driver.
+ */
+int __init acpi_backlight(char *str)
+{
+       if (str == NULL || *str == '\0')
+               return 1;
+       else {
+               if (!strcmp("vendor", str))
+                       acpi_video_support |=
+                               ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR;
+               if (!strcmp("video", str))
+                       acpi_video_support |=
+                               ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VIDEO;
+       }
+       return 1;
+}
+__setup("acpi_backlight=", acpi_backlight);
+
+int __init acpi_display_output(char *str)
+{
+       if (str == NULL || *str == '\0')
+               return 1;
+       else {
+               if (!strcmp("vendor", str))
+                       acpi_video_support |=
+                               ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VENDOR;
+               if (!strcmp("video", str))
+                       acpi_video_support |=
+                               ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VIDEO;
+       }
+       return 1;
+}
+__setup("acpi_display_output=", acpi_display_output);
index fd6a452b0ceb2dd5b809631cbd12d1dc77c31b92..7f23761ace35ff0b78d25b8be6548244d9bac2e6 100644 (file)
@@ -194,6 +194,50 @@ extern bool wmi_has_guid(const char *guid);
 
 #endif /* CONFIG_ACPI_WMI */
 
+#define ACPI_VIDEO_OUTPUT_SWITCHING                    0x0001
+#define ACPI_VIDEO_DEVICE_POSTING                      0x0002
+#define ACPI_VIDEO_ROM_AVAILABLE                       0x0004
+#define ACPI_VIDEO_BACKLIGHT                           0x0008
+#define ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR              0x0010
+#define ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO               0x0020
+#define ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VENDOR       0x0040
+#define ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VIDEO                0x0080
+#define ACPI_VIDEO_BACKLIGHT_DMI_VENDOR                        0x0100
+#define ACPI_VIDEO_BACKLIGHT_DMI_VIDEO                 0x0200
+#define ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VENDOR         0x0400
+#define ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VIDEO          0x0800
+
+#if defined(CONFIG_ACPI_VIDEO) || defined(CONFIG_ACPI_VIDEO_MODULE)
+
+extern long acpi_video_get_capabilities(acpi_handle graphics_dev_handle);
+extern long acpi_is_video_device(struct acpi_device *device);
+extern int acpi_video_backlight_support(void);
+extern int acpi_video_display_switch_support(void);
+
+#else
+
+static inline long acpi_video_get_capabilities(acpi_handle graphics_dev_handle)
+{
+       return 0;
+}
+
+static inline long acpi_is_video_device(struct acpi_device *device)
+{
+       return 0;
+}
+
+static inline int acpi_video_backlight_support(void)
+{
+       return 0;
+}
+
+static inline int acpi_video_display_switch_support(void)
+{
+       return 0;
+}
+
+#endif /* defined(CONFIG_ACPI_VIDEO) || defined(CONFIG_ACPI_VIDEO_MODULE) */
+
 extern int acpi_blacklisted(void);
 #ifdef CONFIG_DMI
 extern void acpi_dmi_osi_linux(int enable, const struct dmi_system_id *d);