diff options
Diffstat (limited to 'drivers/acpi/ec_sys.c')
-rw-r--r-- | drivers/acpi/ec_sys.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/drivers/acpi/ec_sys.c b/drivers/acpi/ec_sys.c new file mode 100644 index 000000000..b4c216bab --- /dev/null +++ b/drivers/acpi/ec_sys.c @@ -0,0 +1,162 @@ +/* + * 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> +#include <linux/module.h> +#include <linux/uaccess.h> +#include "internal.h" + +MODULE_AUTHOR("Thomas Renninger <trenn@suse.de>"); +MODULE_DESCRIPTION("ACPI EC sysfs access driver"); +MODULE_LICENSE("GPL"); + +static bool write_support; +module_param(write_support, bool, 0644); +MODULE_PARM_DESC(write_support, "Dangerous, reboot and removal of battery may " + "be needed."); + +#define EC_SPACE_SIZE 256 + +static struct dentry *acpi_ec_debugfs_dir; + +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; + 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) { + u8 byte_read; + err = ec_read(*off, &byte_read); + if (err) + return err; + if (put_user(byte_read, buf + *off - init_off)) { + if (*off - init_off) + return *off - init_off; /* partial read */ + return -EFAULT; + } + *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; + 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; + if (get_user(byte_write, buf + *off - init_off)) { + if (*off - init_off) + return *off - init_off; /* partial write */ + return -EFAULT; + } + err = ec_write(*off, byte_write); + if (err) + return err; + + *off += 1; + size--; + } + return count; +} + +static const struct file_operations acpi_ec_io_ops = { + .owner = THIS_MODULE, + .open = simple_open, + .read = acpi_ec_read_io, + .write = acpi_ec_write_io, + .llseek = default_llseek, +}; + +static int acpi_ec_add_debugfs(struct acpi_ec *ec, unsigned int ec_device_count) +{ + struct dentry *dev_dir; + char name[64]; + umode_t mode = 0400; + + if (ec_device_count == 0) { + acpi_ec_debugfs_dir = debugfs_create_dir("ec", NULL); + if (!acpi_ec_debugfs_dir) + return -ENOMEM; + } + + sprintf(name, "ec%u", ec_device_count); + dev_dir = debugfs_create_dir(name, acpi_ec_debugfs_dir); + if (!dev_dir) { + if (ec_device_count != 0) + goto error; + return -ENOMEM; + } + + if (!debugfs_create_x32("gpe", 0444, dev_dir, (u32 *)&first_ec->gpe)) + goto error; + if (!debugfs_create_bool("use_global_lock", 0444, dev_dir, + (u32 *)&first_ec->global_lock)) + goto error; + + if (write_support) + mode = 0600; + if (!debugfs_create_file("io", mode, dev_dir, ec, &acpi_ec_io_ops)) + goto error; + + return 0; + +error: + debugfs_remove_recursive(acpi_ec_debugfs_dir); + return -ENOMEM; +} + +static int __init acpi_ec_sys_init(void) +{ + int err = 0; + if (first_ec) + err = acpi_ec_add_debugfs(first_ec, 0); + else + err = -ENODEV; + return err; +} + +static void __exit acpi_ec_sys_exit(void) +{ + debugfs_remove_recursive(acpi_ec_debugfs_dir); +} + +module_init(acpi_ec_sys_init); +module_exit(acpi_ec_sys_exit); |