Re: [PATCH, new ACPI driver] new sony_acpi driver

[Stelian Pop <stelian@popies.net>]

Based on feedback from Jean Delvare and Pekka Enberg, here is an
updated version.

Changes from the previous version include:
- do not initialize to 0 a static variable
- trim to 80 columns
- do not do spurious void * casts
- use c99 style struct initialization
- use simple_strtoul instead of sscanf
- move documentation to new directory Documentation/acpi
- name the file 'brightness' instead of 'brt'

Signed-of-by: Stelian Pop <stelian@popies.net> 

 drivers/acpi/sony_acpi.c                      |  471 +++++++++++++++++++++
 Documentation/acpi/sony_acpi.txt              |   81 +++
 drivers/acpi/Kconfig                          |   15 
 drivers/acpi/Makefile                         |    1 

 4 files changed, 568 insertions(+)

--- /dev/null	2005-02-11 10:21:21.043997848 +0100
+++ linux-2.6-stelian/drivers/acpi/sony_acpi.c	2005-02-11 12:24:41.000000000 +0100
@@ -0,0 +1,471 @@
+/*
+ * ACPI Sony Notebook Control Driver (SNC)
+ *
+ * Copyright (C) 2004 Stelian Pop <stelian@popies.net>
+ * 
+ * Parts of this driver inspired from asus_acpi.c, which is 
+ * Copyright (C) 2002, 2003, 2004 Julien Lerouge, Karol Kozimor
+ *
+ * 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 v0.1"
+
+#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,
+		  },
+};
+
+struct sony_snc {
+	acpi_handle		handle;
+	int			brt;		/* brightness */
+	struct proc_dir_entry	*proc_brt;
+	int			cmi;		/* ??? ? */
+	struct proc_dir_entry	*proc_cmi;
+	int			csxb;		/* ??? */
+	struct proc_dir_entry	*proc_csxb;
+	int			ctr;		/* contrast ? */
+	struct proc_dir_entry	*proc_ctr;
+	int			pbr;		/* ??? */
+	struct proc_dir_entry	*proc_pbr;
+};
+
+static struct proc_dir_entry *sony_acpi_dir;
+
+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_write_brt(struct file *file, const char __user *buffer,
+			       unsigned long count, void *data)
+{
+	struct sony_snc *snc = data;
+	int result;
+
+	if ((result = parse_buffer(buffer, count, &snc->brt)) < 0)
+		return result;
+
+	/* Accept only values between 1 and 8, or VGN-T1XP will hung */
+	if (snc->brt < 1 || snc->brt > 8)
+		return -EINVAL;
+
+	if (acpi_callsetfunc(snc->handle, "SBRT", snc->brt, NULL) < 0)
+		return -EIO;
+
+	return count;
+}
+
+static int sony_acpi_read_brt(char *page, char **start, off_t off, int count,
+			      int *eof, void *data)
+{
+	struct sony_snc *snc = data;
+
+	if (acpi_callgetfunc(snc->handle, "GBRT", &snc->brt) < 0)
+		return -EIO;
+	
+	return sprintf(page, "%d\n", snc->brt);
+}
+
+static int sony_acpi_write_cmi(struct file *file, const char __user *buffer,
+			       unsigned long count, void *data)
+{
+	struct sony_snc *snc = data;
+	int result;
+
+	if ((result = parse_buffer(buffer, count, &snc->cmi)) < 0)
+		return result;
+	
+	if (acpi_callsetfunc(snc->handle, "SCMI", snc->cmi, &snc->cmi) < 0)
+		return -EIO;
+
+	return count;
+}
+
+static int sony_acpi_read_cmi(char *page, char **start, off_t off, int count,
+			      int *eof, void *data)
+{
+	struct sony_snc *snc = data;
+	return sprintf(page, "%d\n", snc->cmi);
+}
+
+static int sony_acpi_write_csxb(struct file *file, const char __user *buffer,
+				unsigned long count, void *data)
+{
+	struct sony_snc *snc = data;
+	int result;
+
+	if ((result = parse_buffer(buffer, count, &snc->csxb)) < 0)
+		return result;
+	
+	if (acpi_callsetfunc(snc->handle, "CSXB", snc->csxb, &snc->csxb) < 0)
+		return -EIO;
+
+	return count;
+}
+
+static int sony_acpi_read_csxb(char *page, char **start, off_t off, int count,
+			       int *eof, void *data)
+{
+	struct sony_snc *snc = data;
+	return sprintf(page, "%d\n", snc->csxb);
+}
+
+static int sony_acpi_write_ctr(struct file *file, const char __user *buffer,
+			       unsigned long count, void *data)
+{
+	struct sony_snc *snc = data;
+	int result;
+
+	if ((result = parse_buffer(buffer, count, &snc->ctr)) < 0)
+		return result;
+	
+	if (acpi_callsetfunc(snc->handle, "SCTR", snc->ctr, NULL) < 0)
+		return -EIO;
+
+	return count;
+}
+
+static int sony_acpi_read_ctr(char *page, char **start, off_t off, int count,
+			      int *eof, void *data)
+{
+	struct sony_snc *snc = data;
+
+	if (acpi_callgetfunc(snc->handle, "GCTR", &snc->ctr) < 0)
+		return -EIO;
+	
+	return sprintf(page, "%d\n", snc->ctr);
+}
+
+static int sony_acpi_write_pbr(struct file *file, const char __user *buffer,
+			       unsigned long count, void *data)
+{
+	struct sony_snc *snc = data;
+	int result;
+
+	if ((result = parse_buffer(buffer, count, &snc->pbr)) < 0)
+		return result;
+	
+	if (acpi_callsetfunc(snc->handle, "SPBR", snc->pbr, NULL) < 0)
+		return -EIO;
+
+	return count;
+}
+
+static int sony_acpi_read_pbr(char *page, char **start, off_t off, int count,
+			      int *eof, void *data)
+{
+	struct sony_snc *snc = data;
+
+	if (acpi_callgetfunc(snc->handle, "GPBR", &snc->pbr) < 0)
+		return -EIO;
+	
+	return sprintf(page, "%d\n", snc->pbr);
+}
+		 
+static void sony_acpi_notify(acpi_handle handle, u32 event, void *data)
+{
+	/* struct sony_snc *snc = data; */
+
+	printk(LOG_PFX "sony_snc_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 __init sony_acpi_add(struct acpi_device *device)
+{
+	acpi_status status = AE_OK;
+	struct sony_snc *snc = NULL;
+	int result;
+
+	snc = kmalloc(sizeof(struct sony_snc), GFP_KERNEL);
+	if (!snc)
+		return -ENOMEM;
+	memset(snc, 0, sizeof(struct sony_snc));
+
+	snc->handle = device->handle;
+
+	acpi_driver_data(device) = snc;
+	acpi_device_dir(device) = sony_acpi_dir;
+
+	if (debug) {
+		status = acpi_walk_namespace(ACPI_TYPE_METHOD, snc->handle, 1,
+					     sony_walk_callback, NULL, NULL);
+		if (ACPI_FAILURE(status)) {
+			printk(LOG_PFX "unable to walk acpi resources\n");
+		}
+	}
+
+	snc->proc_brt = create_proc_entry("brightness", 0600,
+					  acpi_device_dir(device));
+	if (!snc->proc_brt) {
+		printk(LOG_PFX "unable to create proc entry\n");
+		result = -EIO;
+		goto outbrt;
+	}
+
+	snc->proc_brt->write_proc = sony_acpi_write_brt;
+	snc->proc_brt->read_proc = sony_acpi_read_brt;
+	snc->proc_brt->data = acpi_driver_data(device);
+	snc->proc_brt->owner = THIS_MODULE;
+
+	if (debug) {
+		snc->proc_cmi = create_proc_entry("cmi", 0600,
+						  acpi_device_dir(device));
+		if (!snc->proc_cmi) {
+			printk(LOG_PFX "unable to create proc entry\n");
+			result = -EIO;
+			goto outcmi;
+		}
+
+		snc->proc_cmi->write_proc = sony_acpi_write_cmi;
+		snc->proc_cmi->read_proc = sony_acpi_read_cmi;
+		snc->proc_cmi->data = acpi_driver_data(device);
+		snc->proc_cmi->owner = THIS_MODULE;
+
+		snc->proc_csxb = create_proc_entry("csxb", 0600,
+						   acpi_device_dir(device));
+		if (!snc->proc_csxb) {
+			printk(LOG_PFX "unable to create proc entry\n");
+			result = -EIO;
+			goto outcsxb;
+		}
+
+		snc->proc_csxb->write_proc = sony_acpi_write_csxb;
+		snc->proc_csxb->read_proc = sony_acpi_read_csxb;
+		snc->proc_csxb->data = acpi_driver_data(device);
+		snc->proc_csxb->owner = THIS_MODULE;
+
+		snc->proc_ctr = create_proc_entry("ctr", 0600,
+						  acpi_device_dir(device));
+		if (!snc->proc_ctr) {
+			printk(LOG_PFX "unable to create proc entry\n");
+			result = -EIO;
+			goto outctr;
+		}
+
+		snc->proc_ctr->write_proc = sony_acpi_write_ctr;
+		snc->proc_ctr->read_proc = sony_acpi_read_ctr;
+		snc->proc_ctr->data = acpi_driver_data(device);
+		snc->proc_ctr->owner = THIS_MODULE;
+
+		snc->proc_pbr = create_proc_entry("pbr", 0600,
+						  acpi_device_dir(device));
+		if (!snc->proc_pbr) {
+			printk(LOG_PFX "unable to create proc entry\n");
+			result = -EIO;
+			goto outpbr;
+		}
+
+		snc->proc_pbr->write_proc = sony_acpi_write_pbr;
+		snc->proc_pbr->read_proc = sony_acpi_read_pbr;
+		snc->proc_pbr->data = acpi_driver_data(device);
+		snc->proc_pbr->owner = THIS_MODULE;
+
+		status = acpi_install_notify_handler(snc->handle,
+			ACPI_DEVICE_NOTIFY, sony_acpi_notify, snc);
+			if (ACPI_FAILURE(status)) {
+				printk(LOG_PFX "unable to install notify "
+				       "handler\n");
+				result = -ENODEV;
+				goto outnotify;
+		}
+	}
+
+	printk(KERN_INFO ACPI_SNC_DRIVER_NAME " successfully installed\n");
+
+	return 0;
+
+outnotify:
+	remove_proc_entry("pbr", acpi_device_dir(device));
+outpbr:
+	remove_proc_entry("ctr", acpi_device_dir(device));
+outctr:
+	remove_proc_entry("csxb", acpi_device_dir(device));
+outcsxb:
+	remove_proc_entry("cmi", acpi_device_dir(device));
+outcmi:
+	remove_proc_entry("brightness", acpi_device_dir(device));
+outbrt:
+	kfree(snc);
+	return result;
+}
+
+
+static int __exit sony_acpi_remove(struct acpi_device *device, int type)
+{
+	acpi_status status = AE_OK;
+	struct sony_snc *snc = NULL;
+
+	snc = (struct sony_snc *) acpi_driver_data(device);
+
+	if (debug) {
+		status = acpi_remove_notify_handler(snc->handle,
+						    ACPI_DEVICE_NOTIFY,
+						    sony_acpi_notify);
+		if (ACPI_FAILURE(status))
+			printk(LOG_PFX "unable to remove notify handler\n");
+
+		remove_proc_entry("pbr", acpi_device_dir(device));
+		remove_proc_entry("ctr", acpi_device_dir(device));
+		remove_proc_entry("csxb", acpi_device_dir(device));
+		remove_proc_entry("cmi", acpi_device_dir(device));
+	}
+	remove_proc_entry("brightness", acpi_device_dir(device));
+
+	kfree(snc);
+
+	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);
--- /dev/null	2005-02-11 10:21:21.043997848 +0100
+++ linux-2.6-stelian/Documentation/acpi/sony_acpi.txt	2005-02-11 12:08:58.000000000 +0100
@@ -0,0 +1,81 @@
+ACPI Sony Notebook Control Driver (SNC) Readme
+----------------------------------------------
+	Copyright (C) 2004 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, the only thing this driver does is letting
+the user set or query the screen brightness.
+
+You should start by trying the sonypi driver, which does
+all this and many other things. But the sonypi driver does
+not work on all Sony laptops, whereas sony_acpi should 
+work everywhere.
+
+Usage:
+------
+
+Loading the sony_acpi module will create a /proc/acpi/sony/
+directory populated with a couple of files (only one for the
+moment).
+
+You then read/write integer values from/to those files by using
+standard UNIX tools.
+
+For example:
+	# 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.
+
+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.
+
+You can also modify the driver source and add your extra methods
+and retest.
+
+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.
+
--- linux-2.6-linus/drivers/acpi/Kconfig	2005-01-31 16:55:23.000000000 +0100
+++ linux-2.6-stelian/drivers/acpi/Kconfig	2005-02-11 12:10:36.000000000 +0100
@@ -242,6 +242,21 @@
 	  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
+	depends on ACPI_INTERPRETER
+	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 ACPI_INTERPRETER && !STANDALONE
--- linux-2.6-linus/drivers/acpi/Makefile	2005-01-31 16:55:23.000000000 +0100
+++ linux-2.6-stelian/drivers/acpi/Makefile	2005-01-31 17:00:10.000000000 +0100
@@ -54,4 +54,5 @@
 obj-$(CONFIG_ACPI_ASUS)		+= asus_acpi.o
 obj-$(CONFIG_ACPI_IBM)		+= ibm_acpi.o
 obj-$(CONFIG_ACPI_TOSHIBA)	+= toshiba_acpi.o
+obj-$(CONFIG_ACPI_SONY)		+= sony_acpi.o
 obj-$(CONFIG_ACPI_BUS)		+= scan.o motherboard.o
-- 
Stelian Pop <stelian@popies.net>