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authorLinus Torvalds <torvalds@woody.linux-foundation.org>2007-06-08 18:11:47 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-06-08 18:11:47 -0700
commit837525e344298335ea56c3b8c9ca7abbc97f0285 (patch)
treee7afd356670edab6f3550fa9cc0eb9c926b590df /Documentation
parent217397d7d267f832081169016e1ab66691a13e08 (diff)
parent87d37a4f470834223fc8a243af002998bdb5b886 (diff)
downloadop-kernel-dev-837525e344298335ea56c3b8c9ca7abbc97f0285.zip
op-kernel-dev-837525e344298335ea56c3b8c9ca7abbc97f0285.tar.gz
Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6: firmware: remove orphaned Email kobject: use the proper printk level for kobject error Driver core: kill unused code Driver core: keep PHYSDEV for old struct class_device update Documentation/driver-model/platform.txt
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/driver-model/platform.txt40
-rw-r--r--Documentation/firmware_class/README2
-rw-r--r--Documentation/firmware_class/firmware_sample_driver.c2
-rw-r--r--Documentation/firmware_class/firmware_sample_firmware_class.c4
4 files changed, 44 insertions, 4 deletions
diff --git a/Documentation/driver-model/platform.txt b/Documentation/driver-model/platform.txt
index 19c4a6e..2a97320 100644
--- a/Documentation/driver-model/platform.txt
+++ b/Documentation/driver-model/platform.txt
@@ -96,6 +96,46 @@ System setup also associates those clocks with the device, so that that
calls to clk_get(&pdev->dev, clock_name) return them as needed.
+Legacy Drivers: Device Probing
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Some drivers are not fully converted to the driver model, because they take
+on a non-driver role: the driver registers its platform device, rather than
+leaving that for system infrastructure. Such drivers can't be hotplugged
+or coldplugged, since those mechanisms require device creation to be in a
+different system component than the driver.
+
+The only "good" reason for this is to handle older system designs which, like
+original IBM PCs, rely on error-prone "probe-the-hardware" models for hardware
+configuration. Newer systems have largely abandoned that model, in favor of
+bus-level support for dynamic configuration (PCI, USB), or device tables
+provided by the boot firmware (e.g. PNPACPI on x86). There are too many
+conflicting options about what might be where, and even educated guesses by
+an operating system will be wrong often enough to make trouble.
+
+This style of driver is discouraged. If you're updating such a driver,
+please try to move the device enumeration to a more appropriate location,
+outside the driver. This will usually be cleanup, since such drivers
+tend to already have "normal" modes, such as ones using device nodes that
+were created by PNP or by platform device setup.
+
+None the less, there are some APIs to support such legacy drivers. Avoid
+using these calls except with such hotplug-deficient drivers.
+
+ struct platform_device *platform_device_alloc(
+ char *name, unsigned id);
+
+You can use platform_device_alloc() to dynamically allocate a device, which
+you will then initialize with resources and platform_device_register().
+A better solution is usually:
+
+ struct platform_device *platform_device_register_simple(
+ char *name, unsigned id,
+ struct resource *res, unsigned nres);
+
+You can use platform_device_register_simple() as a one-step call to allocate
+and register a device.
+
+
Device Naming and Driver Binding
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The platform_device.dev.bus_id is the canonical name for the devices.
diff --git a/Documentation/firmware_class/README b/Documentation/firmware_class/README
index e9cc8bb..c3480aa 100644
--- a/Documentation/firmware_class/README
+++ b/Documentation/firmware_class/README
@@ -1,7 +1,7 @@
request_firmware() hotplug interface:
------------------------------------
- Copyright (C) 2003 Manuel Estrada Sainz <ranty@debian.org>
+ Copyright (C) 2003 Manuel Estrada Sainz
Why:
---
diff --git a/Documentation/firmware_class/firmware_sample_driver.c b/Documentation/firmware_class/firmware_sample_driver.c
index 87feccd..6865cbe 100644
--- a/Documentation/firmware_class/firmware_sample_driver.c
+++ b/Documentation/firmware_class/firmware_sample_driver.c
@@ -1,7 +1,7 @@
/*
* firmware_sample_driver.c -
*
- * Copyright (c) 2003 Manuel Estrada Sainz <ranty@debian.org>
+ * Copyright (c) 2003 Manuel Estrada Sainz
*
* Sample code on how to use request_firmware() from drivers.
*
diff --git a/Documentation/firmware_class/firmware_sample_firmware_class.c b/Documentation/firmware_class/firmware_sample_firmware_class.c
index 9e1b0e4..4994f1f 100644
--- a/Documentation/firmware_class/firmware_sample_firmware_class.c
+++ b/Documentation/firmware_class/firmware_sample_firmware_class.c
@@ -1,7 +1,7 @@
/*
* firmware_sample_firmware_class.c -
*
- * Copyright (c) 2003 Manuel Estrada Sainz <ranty@debian.org>
+ * Copyright (c) 2003 Manuel Estrada Sainz
*
* NOTE: This is just a probe of concept, if you think that your driver would
* be well served by this mechanism please contact me first.
@@ -19,7 +19,7 @@
#include <linux/firmware.h>
-MODULE_AUTHOR("Manuel Estrada Sainz <ranty@debian.org>");
+MODULE_AUTHOR("Manuel Estrada Sainz");
MODULE_DESCRIPTION("Hackish sample for using firmware class directly");
MODULE_LICENSE("GPL");
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