[kernel/f17] Add platform driver for Apple GMUX device (requested by Matthew Garrett)

Josh Boyer jwboyer at fedoraproject.org
Mon Apr 16 20:21:41 UTC 2012


commit 03aee81210287e4f5b6a408640b702fd1eccd025
Author: Josh Boyer <jwboyer at redhat.com>
Date:   Mon Apr 16 16:04:28 2012 -0400

    Add platform driver for Apple GMUX device (requested by Matthew Garrett)

 apple_bl-Add-register-unregister-functions.patch   |   99 +++++++
 config-x86-generic                                 |    1 +
 kernel.spec                                        |   12 +-
 ...form-x86-Add-driver-for-Apple-gmux-device.patch |  301 ++++++++++++++++++++
 4 files changed, 412 insertions(+), 1 deletions(-)
---
diff --git a/apple_bl-Add-register-unregister-functions.patch b/apple_bl-Add-register-unregister-functions.patch
new file mode 100644
index 0000000..e7f1800
--- /dev/null
+++ b/apple_bl-Add-register-unregister-functions.patch
@@ -0,0 +1,99 @@
+From 83e72dd97a25a831ff270ce4437416943a1e4b36 Mon Sep 17 00:00:00 2001
+From: Seth Forshee <seth.forshee at canonical.com>
+Date: Fri, 16 Mar 2012 14:41:21 -0500
+Subject: [PATCH] apple_bl: Add register/unregister functions
+
+Add functions to allow other modules to enable or disable apple_bl. This
+will be used by the gmux driver to disable apple_bl when the gmux is
+present, as it is a better and more reliable option for brightness
+control.
+
+Signed-off-by: Seth Forshee <seth.forshee at canonical.com>
+Signed-off-by: Matthew Garrett <mjg at redhat.com>
+---
+ drivers/video/backlight/apple_bl.c |   23 +++++++++++++++++++++--
+ include/linux/apple_bl.h           |   26 ++++++++++++++++++++++++++
+ 2 files changed, 47 insertions(+), 2 deletions(-)
+ create mode 100644 include/linux/apple_bl.h
+
+diff --git a/drivers/video/backlight/apple_bl.c b/drivers/video/backlight/apple_bl.c
+index be98d15..a523b25 100644
+--- a/drivers/video/backlight/apple_bl.c
++++ b/drivers/video/backlight/apple_bl.c
+@@ -24,6 +24,7 @@
+ #include <linux/io.h>
+ #include <linux/pci.h>
+ #include <linux/acpi.h>
++#include <linux/atomic.h>
+ 
+ static struct backlight_device *apple_backlight_device;
+ 
+@@ -221,14 +222,32 @@ static struct acpi_driver apple_bl_driver = {
+ 	},
+ };
+ 
++static atomic_t apple_bl_registered = ATOMIC_INIT(0);
++
++int apple_bl_register(void)
++{
++	if (atomic_xchg(&apple_bl_registered, 1) == 0)
++		return acpi_bus_register_driver(&apple_bl_driver);
++
++	return 0;
++}
++EXPORT_SYMBOL_GPL(apple_bl_register);
++
++void apple_bl_unregister(void)
++{
++	if (atomic_xchg(&apple_bl_registered, 0) == 1)
++		acpi_bus_unregister_driver(&apple_bl_driver);
++}
++EXPORT_SYMBOL_GPL(apple_bl_unregister);
++
+ static int __init apple_bl_init(void)
+ {
+-	return acpi_bus_register_driver(&apple_bl_driver);
++	return apple_bl_register();
+ }
+ 
+ static void __exit apple_bl_exit(void)
+ {
+-	acpi_bus_unregister_driver(&apple_bl_driver);
++	apple_bl_unregister();
+ }
+ 
+ module_init(apple_bl_init);
+diff --git a/include/linux/apple_bl.h b/include/linux/apple_bl.h
+new file mode 100644
+index 0000000..47bedc0
+--- /dev/null
++++ b/include/linux/apple_bl.h
+@@ -0,0 +1,26 @@
++/*
++ * apple_bl exported symbols
++ */
++
++#ifndef _LINUX_APPLE_BL_H
++#define _LINUX_APPLE_BL_H
++
++#ifdef CONFIG_BACKLIGHT_APPLE
++
++extern int apple_bl_register(void);
++extern void apple_bl_unregister(void);
++
++#else /* !CONFIG_BACKLIGHT_APPLE */
++
++static inline int apple_bl_register(void)
++{
++	return 0;
++}
++
++static inline void apple_bl_unregister(void)
++{
++}
++
++#endif /* !CONFIG_BACKLIGHT_APPLE */
++
++#endif /* _LINUX_APPLE_BL_H */
+-- 
+1.7.7.6
diff --git a/config-x86-generic b/config-x86-generic
index 96ff564..1b7a87a 100644
--- a/config-x86-generic
+++ b/config-x86-generic
@@ -405,3 +405,4 @@ CONFIG_DRM_GMA500=m
 # Maybe enable in debug kernels?
 # CONFIG_DEBUG_NMI_SELFTEST is not set
 
+CONFIG_APPLE_GMUX=m
diff --git a/kernel.spec b/kernel.spec
index b9070c4..8d8bf84 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -54,7 +54,7 @@ Summary: The Linux kernel
 # For non-released -rc kernels, this will be appended after the rcX and
 # gitX tags, so a 3 here would become part of release "0.rcX.gitX.3"
 #
-%global baserelease 2
+%global baserelease 3
 %global fedora_build %{baserelease}
 
 # base_sublevel is the kernel version we're starting with and patching
@@ -785,6 +785,9 @@ Patch21520: KVM-Ensure-all-vcpus-are-consistent-with-in-kernel-i.patch
 #rhbz 808559
 Patch21530: ALSA-hda-realtek-Add-quirk-for-Mac-Pro-5-1-machines.patch
 
+Patch21600: apple_bl-Add-register-unregister-functions.patch
+Patch21601: platform-x86-Add-driver-for-Apple-gmux-device.patch
+
 Patch22000: weird-root-dentry-name-debug.patch
 
 #selinux ptrace child permissions
@@ -1528,6 +1531,10 @@ ApplyPatch x86-Use-correct-byte-sized-register-constraint-in-__add.patch
 #selinux ptrace child permissions
 ApplyPatch selinux-apply-different-permission-to-ptrace-child.patch
 
+#apple gmux.  blame mjg59
+ApplyPatch apple_bl-Add-register-unregister-functions.patch
+ApplyPatch platform-x86-Add-driver-for-Apple-gmux-device.patch
+
 # END OF PATCH APPLICATIONS
 
 %endif
@@ -2372,6 +2379,9 @@ fi
 #    '-'      |  |
 #              '-'
 %changelog
+* Mon Apr 16 2012 Josh Boyer <jwboyer at redhat.com>
+- Add platform driver for Apple GMUX device (requested by Matthew Garrett)
+
 * Sat Apr 14 2012 Josh Boyer <jwboyer at redhat.com>
 - Add ALSA quirk for MacPro 5,1 machines (rhbz 808559)
 
diff --git a/platform-x86-Add-driver-for-Apple-gmux-device.patch b/platform-x86-Add-driver-for-Apple-gmux-device.patch
new file mode 100644
index 0000000..49548ca
--- /dev/null
+++ b/platform-x86-Add-driver-for-Apple-gmux-device.patch
@@ -0,0 +1,301 @@
+From 917ee75a59160fe3518c1672feb4562f11a18fbc Mon Sep 17 00:00:00 2001
+From: Seth Forshee <seth.forshee at canonical.com>
+Date: Fri, 16 Mar 2012 14:41:22 -0500
+Subject: [PATCH] platform/x86: Add driver for Apple gmux device
+
+Apple laptops with hybrid graphics have a device named gmux that
+controls the muxing of the LVDS panel between the GPUs as well as screen
+brightness. This driver adds support for the gmux device. Only backlight
+control is supported initially.
+
+Signed-off-by: Seth Forshee <seth.forshee at canonical.com>
+Signed-off-by: Matthew Garrett <mjg at redhat.com>
+Tested-by: Grant Likely <grant.likely at secretlab.ca>
+---
+ drivers/platform/x86/Kconfig      |   10 ++
+ drivers/platform/x86/Makefile     |    1 +
+ drivers/platform/x86/apple-gmux.c |  244 +++++++++++++++++++++++++++++++++++++
+ 3 files changed, 255 insertions(+), 0 deletions(-)
+ create mode 100644 drivers/platform/x86/apple-gmux.c
+
+diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
+index ce10f03..c5b4bfe 100644
+--- a/drivers/platform/x86/Kconfig
++++ b/drivers/platform/x86/Kconfig
+@@ -752,4 +752,14 @@ config SAMSUNG_Q10
+ 	  This driver provides support for backlight control on Samsung Q10
+ 	  and related laptops, including Dell Latitude X200.
+ 
++config APPLE_GMUX
++	tristate "Apple Gmux Driver"
++	depends on PNP
++	select BACKLIGHT_CLASS_DEVICE
++	---help---
++	  This driver provides support for the gmux device found on many
++	  Apple laptops, which controls the display mux for the hybrid
++	  graphics as well as the backlight. Currently only backlight
++	  control is supported by the driver.
++
+ endif # X86_PLATFORM_DEVICES
+diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
+index dcfee6b..bf7e4f9 100644
+--- a/drivers/platform/x86/Makefile
++++ b/drivers/platform/x86/Makefile
+@@ -49,3 +49,4 @@ obj-$(CONFIG_MXM_WMI)		+= mxm-wmi.o
+ obj-$(CONFIG_INTEL_MID_POWER_BUTTON)	+= intel_mid_powerbtn.o
+ obj-$(CONFIG_INTEL_OAKTRAIL)	+= intel_oaktrail.o
+ obj-$(CONFIG_SAMSUNG_Q10)	+= samsung-q10.o
++obj-$(CONFIG_APPLE_GMUX)	+= apple-gmux.o
+diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c
+new file mode 100644
+index 0000000..8a582bd
+--- /dev/null
++++ b/drivers/platform/x86/apple-gmux.c
+@@ -0,0 +1,244 @@
++/*
++ *  Gmux driver for Apple laptops
++ *
++ *  Copyright (C) Canonical Ltd. <seth.forshee at canonical.com>
++ *
++ *  This program is free software; you can redistribute it and/or modify
++ *  it under the terms of the GNU General Public License version 2 as
++ *  published by the Free Software Foundation.
++ */
++
++#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
++
++#include <linux/module.h>
++#include <linux/kernel.h>
++#include <linux/init.h>
++#include <linux/backlight.h>
++#include <linux/acpi.h>
++#include <linux/pnp.h>
++#include <linux/apple_bl.h>
++#include <linux/slab.h>
++#include <acpi/video.h>
++#include <asm/io.h>
++
++struct apple_gmux_data {
++	unsigned long iostart;
++	unsigned long iolen;
++
++	struct backlight_device *bdev;
++};
++
++/*
++ * gmux port offsets. Many of these are not yet used, but may be in the
++ * future, and it's useful to have them documented here anyhow.
++ */
++#define GMUX_PORT_VERSION_MAJOR		0x04
++#define GMUX_PORT_VERSION_MINOR		0x05
++#define GMUX_PORT_VERSION_RELEASE	0x06
++#define GMUX_PORT_SWITCH_DISPLAY	0x10
++#define GMUX_PORT_SWITCH_GET_DISPLAY	0x11
++#define GMUX_PORT_INTERRUPT_ENABLE	0x14
++#define GMUX_PORT_INTERRUPT_STATUS	0x16
++#define GMUX_PORT_SWITCH_DDC		0x28
++#define GMUX_PORT_SWITCH_EXTERNAL	0x40
++#define GMUX_PORT_SWITCH_GET_EXTERNAL	0x41
++#define GMUX_PORT_DISCRETE_POWER	0x50
++#define GMUX_PORT_MAX_BRIGHTNESS	0x70
++#define GMUX_PORT_BRIGHTNESS		0x74
++
++#define GMUX_MIN_IO_LEN			(GMUX_PORT_BRIGHTNESS + 4)
++
++#define GMUX_INTERRUPT_ENABLE		0xff
++#define GMUX_INTERRUPT_DISABLE		0x00
++
++#define GMUX_INTERRUPT_STATUS_ACTIVE	0
++#define GMUX_INTERRUPT_STATUS_DISPLAY	(1 << 0)
++#define GMUX_INTERRUPT_STATUS_POWER	(1 << 2)
++#define GMUX_INTERRUPT_STATUS_HOTPLUG	(1 << 3)
++
++#define GMUX_BRIGHTNESS_MASK		0x00ffffff
++#define GMUX_MAX_BRIGHTNESS		GMUX_BRIGHTNESS_MASK
++
++static inline u8 gmux_read8(struct apple_gmux_data *gmux_data, int port)
++{
++	return inb(gmux_data->iostart + port);
++}
++
++static inline void gmux_write8(struct apple_gmux_data *gmux_data, int port,
++			       u8 val)
++{
++	outb(val, gmux_data->iostart + port);
++}
++
++static inline u32 gmux_read32(struct apple_gmux_data *gmux_data, int port)
++{
++	return inl(gmux_data->iostart + port);
++}
++
++static int gmux_get_brightness(struct backlight_device *bd)
++{
++	struct apple_gmux_data *gmux_data = bl_get_data(bd);
++	return gmux_read32(gmux_data, GMUX_PORT_BRIGHTNESS) &
++	       GMUX_BRIGHTNESS_MASK;
++}
++
++static int gmux_update_status(struct backlight_device *bd)
++{
++	struct apple_gmux_data *gmux_data = bl_get_data(bd);
++	u32 brightness = bd->props.brightness;
++
++	/*
++	 * Older gmux versions require writing out lower bytes first then
++	 * setting the upper byte to 0 to flush the values. Newer versions
++	 * accept a single u32 write, but the old method also works, so we
++	 * just use the old method for all gmux versions.
++	 */
++	gmux_write8(gmux_data, GMUX_PORT_BRIGHTNESS, brightness);
++	gmux_write8(gmux_data, GMUX_PORT_BRIGHTNESS + 1, brightness >> 8);
++	gmux_write8(gmux_data, GMUX_PORT_BRIGHTNESS + 2, brightness >> 16);
++	gmux_write8(gmux_data, GMUX_PORT_BRIGHTNESS + 3, 0);
++
++	return 0;
++}
++
++static const struct backlight_ops gmux_bl_ops = {
++	.get_brightness = gmux_get_brightness,
++	.update_status = gmux_update_status,
++};
++
++static int __devinit gmux_probe(struct pnp_dev *pnp,
++				const struct pnp_device_id *id)
++{
++	struct apple_gmux_data *gmux_data;
++	struct resource *res;
++	struct backlight_properties props;
++	struct backlight_device *bdev;
++	u8 ver_major, ver_minor, ver_release;
++	int ret = -ENXIO;
++
++	gmux_data = kzalloc(sizeof(*gmux_data), GFP_KERNEL);
++	if (!gmux_data)
++		return -ENOMEM;
++	pnp_set_drvdata(pnp, gmux_data);
++
++	res = pnp_get_resource(pnp, IORESOURCE_IO, 0);
++	if (!res) {
++		pr_err("Failed to find gmux I/O resource\n");
++		goto err_free;
++	}
++
++	gmux_data->iostart = res->start;
++	gmux_data->iolen = res->end - res->start;
++
++	if (gmux_data->iolen < GMUX_MIN_IO_LEN) {
++		pr_err("gmux I/O region too small (%lu < %u)\n",
++		       gmux_data->iolen, GMUX_MIN_IO_LEN);
++		goto err_free;
++	}
++
++	if (!request_region(gmux_data->iostart, gmux_data->iolen,
++			    "Apple gmux")) {
++		pr_err("gmux I/O already in use\n");
++		goto err_free;
++	}
++
++	/*
++	 * On some machines the gmux is in ACPI even thought the machine
++	 * doesn't really have a gmux. Check for invalid version information
++	 * to detect this.
++	 */
++	ver_major = gmux_read8(gmux_data, GMUX_PORT_VERSION_MAJOR);
++	ver_minor = gmux_read8(gmux_data, GMUX_PORT_VERSION_MINOR);
++	ver_release = gmux_read8(gmux_data, GMUX_PORT_VERSION_RELEASE);
++	if (ver_major == 0xff && ver_minor == 0xff && ver_release == 0xff) {
++		pr_info("gmux device not present\n");
++		ret = -ENODEV;
++		goto err_release;
++	}
++
++	pr_info("Found gmux version %d.%d.%d\n", ver_major, ver_minor,
++		ver_release);
++
++	memset(&props, 0, sizeof(props));
++	props.type = BACKLIGHT_PLATFORM;
++	props.max_brightness = gmux_read32(gmux_data, GMUX_PORT_MAX_BRIGHTNESS);
++
++	/*
++	 * Currently it's assumed that the maximum brightness is less than
++	 * 2^24 for compatibility with old gmux versions. Cap the max
++	 * brightness at this value, but print a warning if the hardware
++	 * reports something higher so that it can be fixed.
++	 */
++	if (WARN_ON(props.max_brightness > GMUX_MAX_BRIGHTNESS))
++		props.max_brightness = GMUX_MAX_BRIGHTNESS;
++
++	bdev = backlight_device_register("gmux_backlight", &pnp->dev,
++					 gmux_data, &gmux_bl_ops, &props);
++	if (IS_ERR(bdev)) {
++		ret = PTR_ERR(bdev);
++		goto err_release;
++	}
++
++	gmux_data->bdev = bdev;
++	bdev->props.brightness = gmux_get_brightness(bdev);
++	backlight_update_status(bdev);
++
++	/*
++	 * The backlight situation on Macs is complicated. If the gmux is
++	 * present it's the best choice, because it always works for
++	 * backlight control and supports more levels than other options.
++	 * Disable the other backlight choices.
++	 */
++	acpi_video_unregister();
++	apple_bl_unregister();
++
++	return 0;
++
++err_release:
++	release_region(gmux_data->iostart, gmux_data->iolen);
++err_free:
++	kfree(gmux_data);
++	return ret;
++}
++
++static void __devexit gmux_remove(struct pnp_dev *pnp)
++{
++	struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);
++
++	backlight_device_unregister(gmux_data->bdev);
++	release_region(gmux_data->iostart, gmux_data->iolen);
++	kfree(gmux_data);
++
++	acpi_video_register();
++	apple_bl_register();
++}
++
++static const struct pnp_device_id gmux_device_ids[] = {
++	{"APP000B", 0},
++	{"", 0}
++};
++
++static struct pnp_driver gmux_pnp_driver = {
++	.name		= "apple-gmux",
++	.probe		= gmux_probe,
++	.remove		= __devexit_p(gmux_remove),
++	.id_table	= gmux_device_ids,
++};
++
++static int __init apple_gmux_init(void)
++{
++	return pnp_register_driver(&gmux_pnp_driver);
++}
++
++static void __exit apple_gmux_exit(void)
++{
++	pnp_unregister_driver(&gmux_pnp_driver);
++}
++
++module_init(apple_gmux_init);
++module_exit(apple_gmux_exit);
++
++MODULE_AUTHOR("Seth Forshee <seth.forshee at canonical.com>");
++MODULE_DESCRIPTION("Apple Gmux Driver");
++MODULE_LICENSE("GPL");
++MODULE_DEVICE_TABLE(pnp, gmux_device_ids);
+-- 
+1.7.7.6
+


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