sony_acpi: SNC device support for Sony Vaios

From: Bjorn Helgaas <bjorn.helgaas@hp.com>

  Even though the devices claimed by sony_acpi.c can not be hot-plugged, the
  driver registration infrastructure allows the .add() and .remove() methods
  to be called at any time while the driver is registered.  So remove __init
  and __exit from them.

From: Matthew Garrett <mjg59@srcf.ucam.org>

[UBUNTU:acpi/sony] Add FN hotkey support
Source URL of Patch:
http://www.kernel.org/git/?p=linux/kernel/git/bcollins/ubuntu-dapper.git;a=commitdiff;h=7a9b49cba4919e8506604629db03add8e0b85767

Signed-off-by: Ben Collins <bcollins@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Len Brown <len.brown@intel.com>

Documentation/acpi/sony_acpi.txt

@@ -0,0 +1,87 @@
+ACPI Sony Notebook Control Driver (SNC) Readme
+----------------------------------------------
+	Copyright (C) 2004- 2005 Stelian Pop <stelian@popies.net>
+
+This mini-driver drives the ACPI SNC device present in the
+ACPI BIOS of the Sony Vaio laptops.
+
+It gives access to some extra laptop functionalities. In
+its current form, this driver is mainly useful for controlling the
+screen brightness, but it may do more in the future.
+
+You should probably start by trying the sonypi driver, and try
+sony_acpi only if sonypi doesn't work for you.
+
+Usage:
+------
+
+Loading the sony_acpi module will create a /proc/acpi/sony/
+directory populated with a couple of files.
+
+You then read/write integer values from/to those files by using
+standard UNIX tools.
+
+The files are:
+	brightness		current screen brightness
+	brightness_default	screen brightness which will be set
+				when the laptop will be rebooted
+	cdpower			power on/off the internal CD drive
+
+Note that some files may be missing if they are not supported
+by your particular laptop model.
+
+Example usage:
+	# echo "1" > /proc/acpi/sony/brightness
+sets the lowest screen brightness,
+	# echo "8" > /proc/acpi/sony/brightness
+sets the highest screen brightness,
+	# cat /proc/acpi/sony/brightness
+retrieves the current screen brightness.
+
+Development:
+------------
+
+If you want to help with the development of this driver (and
+you are not afraid of any side effects doing strange things with
+your ACPI BIOS could have on your laptop), load the driver and
+pass the option 'debug=1'.
+
+REPEAT: DON'T DO THIS IF YOU DON'T LIKE RISKY BUSINESS.
+
+In your kernel logs you will find the list of all ACPI methods
+the SNC device has on your laptop. You can see the GBRT/SBRT methods
+used to get/set the brightness, but there are others.
+
+I HAVE NO IDEA WHAT THOSE METHODS DO.
+
+The sony_acpi driver creates, for some of those methods (the most
+current ones found on several Vaio models), an entry under
+/proc/acpi/sony/, just like the 'brightness' one. You can create
+other entries corresponding to your own laptop methods by further
+editing the source (see the 'sony_acpi_values' table, and add a new
+structure to this table with your get/set method names).
+
+Your mission, should you accept it, is to try finding out what
+those entries are for, by reading/writing random values from/to those
+files and find out what is the impact on your laptop.
+
+Should you find anything interesting, please report it back to me,
+I will not disavow all knowledge of your actions :)
+
+Bugs/Limitations:
+-----------------
+
+* This driver is not based on official documentation from Sony
+  (because there is none), so there is no guarantee this driver
+  will work at all, or do the right thing. Although this hasn't
+  happened to me, this driver could do very bad things to your
+  laptop, including permanent damage.
+
+* The sony_acpi and sonypi drivers do not interact at all. In the
+  future, sonypi could use sony_acpi to do (part of) its business.
+
+* spicctrl, which is the userspace tool used to communicate with the
+  sonypi driver (through /dev/sonypi) does not try to use the
+  sony_acpi driver. In the future, spicctrl could try sonypi first,
+  and if it isn't present, try sony_acpi instead.
+

drivers/acpi/Kconfig

@@ -252,6 +252,20 @@ config ACPI_TOSHIBA
 	  If you have a legacy free Toshiba laptop (such as the Libretto L1
 	  series), say Y.
 
+config ACPI_SONY
+	tristate "Sony Laptop Extras"
+	depends on X86 && ACPI
+	default m
+	  ---help---
+	  This mini-driver drives the ACPI SNC device present in the
+	  ACPI BIOS of the Sony Vaio laptops.
+
+	  It gives access to some extra laptop functionalities. In
+	  its current form, the only thing this driver does is letting
+	  the user set or query the screen brightness.
+
+	  Read <file:Documentation/acpi/sony_acpi.txt> for more information.
+
 config ACPI_CUSTOM_DSDT
 	bool "Include Custom DSDT"
 	depends on !STANDALONE

drivers/acpi/Makefile

@@ -53,6 +53,7 @@ obj-$(CONFIG_ACPI_THERMAL)	+= thermal.o
 obj-$(CONFIG_ACPI_SYSTEM)	+= system.o event.o
 obj-$(CONFIG_ACPI_DEBUG)	+= debug.o
 obj-$(CONFIG_ACPI_NUMA)		+= numa.o
+obj-$(CONFIG_ACPI_SONY)		+= sony_acpi.o
 obj-$(CONFIG_ACPI_ASUS)		+= asus_acpi.o
 obj-$(CONFIG_ACPI_IBM)		+= ibm_acpi.o
 obj-$(CONFIG_ACPI_TOSHIBA)	+= toshiba_acpi.o

drivers/acpi/sony_acpi.c

@@ -0,0 +1,397 @@
+/*
+ * ACPI Sony Notebook Control Driver (SNC)
+ *
+ * Copyright (C) 2004-2005 Stelian Pop <stelian@popies.net>
+ *
+ * Parts of this driver inspired from asus_acpi.c and ibm_acpi.c
+ * which are copyrighted by their respective authors.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <acpi/acpi_drivers.h>
+#include <acpi/acpi_bus.h>
+#include <asm/uaccess.h>
+
+#define ACPI_SNC_CLASS		"sony"
+#define ACPI_SNC_HID		"SNY5001"
+#define ACPI_SNC_DRIVER_NAME	"ACPI Sony Notebook Control Driver v0.2"
+
+#define LOG_PFX			KERN_WARNING "sony_acpi: "
+
+MODULE_AUTHOR("Stelian Pop");
+MODULE_DESCRIPTION(ACPI_SNC_DRIVER_NAME);
+MODULE_LICENSE("GPL");
+
+static int debug;
+module_param(debug, int, 0);
+MODULE_PARM_DESC(debug, "set this to 1 (and RTFM) if you want to help "
+			"the development of this driver");
+
+static int sony_acpi_add (struct acpi_device *device);
+static int sony_acpi_remove (struct acpi_device *device, int type);
+
+static struct acpi_driver sony_acpi_driver = {
+	.name	= ACPI_SNC_DRIVER_NAME,
+	.class	= ACPI_SNC_CLASS,
+	.ids	= ACPI_SNC_HID,
+	.ops	= {
+			.add	= sony_acpi_add,
+			.remove	= sony_acpi_remove,
+		  },
+};
+
+static acpi_handle sony_acpi_handle;
+static struct proc_dir_entry *sony_acpi_dir;
+
+static struct sony_acpi_value {
+	char			*name;	 /* name of the entry */
+	struct proc_dir_entry 	*proc;	 /* /proc entry */
+	char			*acpiget;/* name of the ACPI get function */
+	char			*acpiset;/* name of the ACPI get function */
+	int 			min;	 /* minimum allowed value or -1 */
+	int			max;	 /* maximum allowed value or -1 */
+	int			debug;	 /* active only in debug mode ? */
+} sony_acpi_values[] = {
+	{
+		.name		= "brightness",
+		.acpiget	= "GBRT",
+		.acpiset	= "SBRT",
+		.min		= 1,
+		.max		= 8,
+		.debug		= 0,
+	},
+	{
+		.name		= "brightness_default",
+		.acpiget	= "GPBR",
+		.acpiset	= "SPBR",
+		.min		= 1,
+		.max		= 8,
+		.debug		= 0,
+	},
+	{
+		.name           = "fnkey",
+		.acpiget        = "GHKE",
+		.debug          = 0,
+	},
+	{
+		.name		= "cdpower",
+		.acpiget	= "GCDP",
+		.acpiset	= "SCDP",
+		.min		= -1,
+		.max		= -1,
+		.debug		= 0,
+	},
+	{
+		.name		= "PID",
+		.acpiget	= "GPID",
+		.debug		= 1,
+	},
+	{
+		.name		= "CTR",
+		.acpiget	= "GCTR",
+		.acpiset	= "SCTR",
+		.min		= -1,
+		.max		= -1,
+		.debug		= 1,
+	},
+	{
+		.name		= "PCR",
+		.acpiget	= "GPCR",
+		.acpiset	= "SPCR",
+		.min		= -1,
+		.max		= -1,
+		.debug		= 1,
+	},
+	{
+		.name		= "CMI",
+		.acpiget	= "GCMI",
+		.acpiset	= "SCMI",
+		.min		= -1,
+		.max		= -1,
+		.debug		= 1,
+	},
+	{
+		.name		= NULL,
+	}
+};
+
+static int acpi_callgetfunc(acpi_handle handle, char *name, int *result)
+{
+	struct acpi_buffer output;
+	union acpi_object out_obj;
+	acpi_status status;
+
+	output.length = sizeof(out_obj);
+	output.pointer = &out_obj;
+
+	status = acpi_evaluate_object(handle, name, NULL, &output);
+	if ((status == AE_OK) && (out_obj.type == ACPI_TYPE_INTEGER)) {
+		*result = out_obj.integer.value;
+		return 0;
+	}
+
+	printk(LOG_PFX "acpi_callreadfunc failed\n");
+
+	return -1;
+}
+
+static int acpi_callsetfunc(acpi_handle handle, char *name, int value,
+			    int *result)
+{
+	struct acpi_object_list params;
+	union acpi_object in_obj;
+	struct acpi_buffer output;
+	union acpi_object out_obj;
+	acpi_status status;
+
+	params.count = 1;
+	params.pointer = &in_obj;
+	in_obj.type = ACPI_TYPE_INTEGER;
+	in_obj.integer.value = value;
+
+	output.length = sizeof(out_obj);
+	output.pointer = &out_obj;
+
+	status = acpi_evaluate_object(handle, name, &params, &output);
+	if (status == AE_OK) {
+		if (result != NULL) {
+			if (out_obj.type != ACPI_TYPE_INTEGER) {
+				printk(LOG_PFX "acpi_evaluate_object bad "
+				       "return type\n");
+				return -1;
+			}
+			*result = out_obj.integer.value;
+		}
+		return 0;
+	}
+
+	printk(LOG_PFX "acpi_evaluate_object failed\n");
+
+	return -1;
+}
+
+static int parse_buffer(const char __user *buffer, unsigned long count,
+			int *val) {
+	char s[32];
+	int ret;
+
+	if (count > 31)
+		return -EINVAL;
+	if (copy_from_user(s, buffer, count))
+		return -EFAULT;
+	s[count] = '\0';
+	ret = simple_strtoul(s, NULL, 10);
+	*val = ret;
+	return 0;
+}
+
+static int sony_acpi_read(char* page, char** start, off_t off, int count,
+			  int* eof, void *data)
+{
+	struct sony_acpi_value *item = data;
+	int value;
+
+	if (!item->acpiget)
+		return -EIO;
+
+	if (acpi_callgetfunc(sony_acpi_handle, item->acpiget, &value) < 0)
+		return -EIO;
+
+	return sprintf(page, "%d\n", value);
+}
+
+static int sony_acpi_write(struct file *file, const char __user *buffer,
+			   unsigned long count, void *data)
+{
+	struct sony_acpi_value *item = data;
+	int result;
+	int value;
+
+	if (!item->acpiset)
+		return -EIO;
+
+	if ((result = parse_buffer(buffer, count, &value)) < 0)
+		return result;
+
+	if (item->min != -1 && value < item->min)
+		return -EINVAL;
+	if (item->max != -1 && value > item->max)
+		return -EINVAL;
+
+	if (acpi_callsetfunc(sony_acpi_handle, item->acpiset, value, NULL) < 0)
+		return -EIO;
+
+	return count;
+}
+
+static void sony_acpi_notify(acpi_handle handle, u32 event, void *data)
+{
+	printk(LOG_PFX "sony_acpi_notify\n");
+}
+
+static acpi_status sony_walk_callback(acpi_handle handle, u32 level,
+				      void *context, void **return_value)
+{
+	struct acpi_namespace_node *node;
+	union acpi_operand_object *operand;
+
+	node = (struct acpi_namespace_node *) handle;
+	operand = (union acpi_operand_object *) node->object;
+
+	printk(LOG_PFX "method: name: %4.4s, args %X\n", node->name.ascii,
+	       (u32) operand->method.param_count);
+
+	return AE_OK;
+}
+
+static int sony_acpi_add(struct acpi_device *device)
+{
+	acpi_status status;
+	int result;
+	struct sony_acpi_value *item;
+
+	sony_acpi_handle = device->handle;
+
+	acpi_driver_data(device) = NULL;
+	acpi_device_dir(device) = sony_acpi_dir;
+
+	if (debug) {
+		status = acpi_walk_namespace(ACPI_TYPE_METHOD, sony_acpi_handle,
+					     1, sony_walk_callback, NULL, NULL);
+		if (ACPI_FAILURE(status)) {
+			printk(LOG_PFX "unable to walk acpi resources\n");
+			result = -ENODEV;
+			goto outwalk;
+		}
+
+		status = acpi_install_notify_handler(sony_acpi_handle,
+						     ACPI_DEVICE_NOTIFY,
+						     sony_acpi_notify,
+						     NULL);
+		if (ACPI_FAILURE(status)) {
+			printk(LOG_PFX "unable to install notify handler\n");
+			result = -ENODEV;
+			goto outnotify;
+		}
+	}
+
+	for (item = sony_acpi_values; item->name; ++item) {
+		acpi_handle handle;
+
+		if (!debug && item->debug)
+			continue;
+
+		if (item->acpiget &&
+		    ACPI_FAILURE(acpi_get_handle(sony_acpi_handle,
+		    		 item->acpiget, &handle)))
+		    	continue;
+
+		if (item->acpiset &&
+		    ACPI_FAILURE(acpi_get_handle(sony_acpi_handle,
+		    		 item->acpiset, &handle)))
+		    	continue;
+
+		item->proc = create_proc_entry(item->name, 0600,
+					       acpi_device_dir(device));
+		if (!item->proc) {
+			printk(LOG_PFX "unable to create proc entry\n");
+			result = -EIO;
+			goto outproc;
+		}
+
+		item->proc->read_proc = sony_acpi_read;
+		item->proc->write_proc = sony_acpi_write;
+		item->proc->data = item;
+		item->proc->owner = THIS_MODULE;
+	}
+
+	printk(KERN_INFO ACPI_SNC_DRIVER_NAME " successfully installed\n");
+
+	return 0;
+
+outproc:
+	if (debug) {
+		status = acpi_remove_notify_handler(sony_acpi_handle,
+						    ACPI_DEVICE_NOTIFY,
+						    sony_acpi_notify);
+		if (ACPI_FAILURE(status))
+			printk(LOG_PFX "unable to remove notify handler\n");
+	}
+outnotify:
+	for (item = sony_acpi_values; item->name; ++item)
+		if (item->proc)
+			remove_proc_entry(item->name, acpi_device_dir(device));
+outwalk:
+	return result;
+}
+
+
+static int sony_acpi_remove(struct acpi_device *device, int type)
+{
+	acpi_status status;
+	struct sony_acpi_value *item;
+
+	if (debug) {
+		status = acpi_remove_notify_handler(sony_acpi_handle,
+						    ACPI_DEVICE_NOTIFY,
+						    sony_acpi_notify);
+		if (ACPI_FAILURE(status))
+			printk(LOG_PFX "unable to remove notify handler\n");
+	}
+
+	for (item = sony_acpi_values; item->name; ++item)
+		if (item->proc)
+			remove_proc_entry(item->name, acpi_device_dir(device));
+
+	printk(KERN_INFO ACPI_SNC_DRIVER_NAME " successfully removed\n");
+
+	return 0;
+}
+
+static int __init sony_acpi_init(void)
+{
+	int result;
+
+	sony_acpi_dir = proc_mkdir("sony", acpi_root_dir);
+	if (!sony_acpi_dir) {
+		printk(LOG_PFX "unable to create /proc entry\n");
+		return -ENODEV;
+	}
+	sony_acpi_dir->owner = THIS_MODULE;
+
+	result = acpi_bus_register_driver(&sony_acpi_driver);
+	if (result < 0) {
+		remove_proc_entry("sony", acpi_root_dir);
+		return -ENODEV;
+	}
+	return 0;
+}
+
+
+static void __exit sony_acpi_exit(void)
+{
+	acpi_bus_unregister_driver(&sony_acpi_driver);
+	remove_proc_entry("sony", acpi_root_dir);
+}
+
+module_init(sony_acpi_init);
+module_exit(sony_acpi_exit);