Commit 9827886d authored by Thomas Renninger's avatar Thomas Renninger Committed by Matthew Garrett
Browse files

ACPI: Provide /sys/kernel/debug//ec/ec0/io for binary access to the EC 

A userspace app to easily read/write the EC can be found here:
ftp://ftp.suse.com/pub/people/trenn/sources/ec/ec_access.c



Multiple ECs are not supported, but shouldn't be hard to add as soon
as the ec driver itself will support them.

Signed-off-by: default avatarThomas Renninger <trenn@suse.de>
CC: Alexey Starikovskiy <astarikovskiy@suse.de>
CC: Len Brown <lenb@kernel.org>
CC: linux-kernel@vger.kernel.org
CC: linux-acpi@vger.kernel.org
CC: platform-driver-x86@vger.kernel.org
Signed-off-by: default avatarMatthew Garrett <mjg@redhat.com>
parent 1195a098

drivers/acpi/ec_sys.c

+86 −0
Original line number Diff line number Diff line 
/*

 * ec_sys.c

 *

 * Copyright (C) 2010 SUSE Products GmbH/Novell

 * Author:

 *      Thomas Renninger <trenn@suse.de>

 *

 * This work is licensed under the terms of the GNU GPL, version 2.

 */



#include <linux/kernel.h>

#include <linux/acpi.h>

#include <linux/debugfs.h>
@@ -7,12 +17,87 @@ MODULE_AUTHOR("Thomas Renninger <trenn@suse.de>"); 
MODULE_DESCRIPTION("ACPI EC sysfs access driver");

MODULE_LICENSE("GPL");



#define EC_SPACE_SIZE 256



struct sysdev_class acpi_ec_sysdev_class = {

	.name = "ec",

};



static struct dentry *acpi_ec_debugfs_dir;



static int acpi_ec_open_io(struct inode *i, struct file *f)

{

	f->private_data = i->i_private;

	return 0;

}



static ssize_t acpi_ec_read_io(struct file *f, char __user *buf,

			       size_t count, loff_t *off)

{

	/* Use this if support reading/writing multiple ECs exists in ec.c:

	 * struct acpi_ec *ec = ((struct seq_file *)f->private_data)->private;

	 */

	unsigned int size = EC_SPACE_SIZE;

	u8 *data = (u8 *) buf;

	loff_t init_off = *off;

	int err = 0;



	if (*off >= size)

		return 0;

	if (*off + count >= size) {

		size -= *off;

		count = size;

	} else

		size = count;



	while (size) {

		err = ec_read(*off, &data[*off - init_off]);

		if (err)

			return err;

		*off += 1;

		size--;

	}

	return count;

}



static ssize_t acpi_ec_write_io(struct file *f, const char __user *buf,

				size_t count, loff_t *off)

{

	/* Use this if support reading/writing multiple ECs exists in ec.c:

	 * struct acpi_ec *ec = ((struct seq_file *)f->private_data)->private;

	 */



	unsigned int size = count;

	loff_t init_off = *off;

	u8 *data = (u8 *) buf;

	int err = 0;



	if (*off >= EC_SPACE_SIZE)

		return 0;

	if (*off + count >= EC_SPACE_SIZE) {

		size = EC_SPACE_SIZE - *off;

		count = size;

	}



	while (size) {

		u8 byte_write = data[*off - init_off];

		err = ec_write(*off, byte_write);

		if (err)

			return err;



		*off += 1;

		size--;

	}

	return count;

}



static struct file_operations acpi_ec_io_ops = {

	.owner = THIS_MODULE,

	.open  = acpi_ec_open_io,

	.read  = acpi_ec_read_io,

	.write = acpi_ec_write_io,

};



int acpi_ec_add_debugfs(struct acpi_ec *ec, unsigned int ec_device_count)

{

	struct dentry *dev_dir;
@@ -35,6 +120,7 @@ int acpi_ec_add_debugfs(struct acpi_ec *ec, unsigned int ec_device_count) 
	debugfs_create_x32("gpe", 0444, dev_dir, (u32 *)&first_ec->gpe);

	debugfs_create_bool("use_global_lock", 0444, dev_dir,

			    (u32 *)&first_ec->global_lock);

	debugfs_create_file("io", 0666, dev_dir, ec, &acpi_ec_io_ops);

	return 0;

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE