1/* 2 * ec_sys.c 3 * 4 * Copyright (C) 2010 SUSE Products GmbH/Novell 5 * Author: 6 * Thomas Renninger <trenn@suse.de> 7 * 8 * This work is licensed under the terms of the GNU GPL, version 2. 9 */ 10 11#include <linux/kernel.h> 12#include <linux/acpi.h> 13#include <linux/debugfs.h> 14#include "internal.h" 15 16MODULE_AUTHOR("Thomas Renninger <trenn@suse.de>"); 17MODULE_DESCRIPTION("ACPI EC sysfs access driver"); 18MODULE_LICENSE("GPL"); 19 20static bool write_support; 21module_param(write_support, bool, 0644); 22MODULE_PARM_DESC(write_support, "Dangerous, reboot and removal of battery may " 23 "be needed."); 24 25#define EC_SPACE_SIZE 256 26 27struct sysdev_class acpi_ec_sysdev_class = { 28 .name = "ec", 29}; 30 31static struct dentry *acpi_ec_debugfs_dir; 32 33static int acpi_ec_open_io(struct inode *i, struct file *f) 34{ 35 f->private_data = i->i_private; 36 return 0; 37} 38 39static ssize_t acpi_ec_read_io(struct file *f, char __user *buf, 40 size_t count, loff_t *off) 41{ 42 /* Use this if support reading/writing multiple ECs exists in ec.c: 43 * struct acpi_ec *ec = ((struct seq_file *)f->private_data)->private; 44 */ 45 unsigned int size = EC_SPACE_SIZE; 46 u8 *data = (u8 *) buf; 47 loff_t init_off = *off; 48 int err = 0; 49 50 if (*off >= size) 51 return 0; 52 if (*off + count >= size) { 53 size -= *off; 54 count = size; 55 } else 56 size = count; 57 58 while (size) { 59 err = ec_read(*off, &data[*off - init_off]); 60 if (err) 61 return err; 62 *off += 1; 63 size--; 64 } 65 return count; 66} 67 68static ssize_t acpi_ec_write_io(struct file *f, const char __user *buf, 69 size_t count, loff_t *off) 70{ 71 /* Use this if support reading/writing multiple ECs exists in ec.c: 72 * struct acpi_ec *ec = ((struct seq_file *)f->private_data)->private; 73 */ 74 75 unsigned int size = count; 76 loff_t init_off = *off; 77 u8 *data = (u8 *) buf; 78 int err = 0; 79 80 if (*off >= EC_SPACE_SIZE) 81 return 0; 82 if (*off + count >= EC_SPACE_SIZE) { 83 size = EC_SPACE_SIZE - *off; 84 count = size; 85 } 86 87 while (size) { 88 u8 byte_write = data[*off - init_off]; 89 err = ec_write(*off, byte_write); 90 if (err) 91 return err; 92 93 *off += 1; 94 size--; 95 } 96 return count; 97} 98 99static struct file_operations acpi_ec_io_ops = { 100 .owner = THIS_MODULE, 101 .open = acpi_ec_open_io, 102 .read = acpi_ec_read_io, 103 .write = acpi_ec_write_io, 104}; 105 106int acpi_ec_add_debugfs(struct acpi_ec *ec, unsigned int ec_device_count) 107{ 108 struct dentry *dev_dir; 109 char name[64]; 110 mode_t mode = 0400; 111 112 if (ec_device_count == 0) { 113 acpi_ec_debugfs_dir = debugfs_create_dir("ec", NULL); 114 if (!acpi_ec_debugfs_dir) 115 return -ENOMEM; 116 } 117 118 sprintf(name, "ec%u", ec_device_count); 119 dev_dir = debugfs_create_dir(name, acpi_ec_debugfs_dir); 120 if (!dev_dir) { 121 if (ec_device_count != 0) 122 goto error; 123 return -ENOMEM; 124 } 125 126 if (!debugfs_create_x32("gpe", 0444, dev_dir, (u32 *)&first_ec->gpe)) 127 goto error; 128 if (!debugfs_create_bool("use_global_lock", 0444, dev_dir, 129 (u32 *)&first_ec->global_lock)) 130 goto error; 131 132 if (write_support) 133 mode = 0600; 134 if (!debugfs_create_file("io", mode, dev_dir, ec, &acpi_ec_io_ops)) 135 goto error; 136 137 return 0; 138 139error: 140 debugfs_remove_recursive(acpi_ec_debugfs_dir); 141 return -ENOMEM; 142} 143 144static int __init acpi_ec_sys_init(void) 145{ 146 int err = 0; 147 if (first_ec) 148 err = acpi_ec_add_debugfs(first_ec, 0); 149 else 150 err = -ENODEV; 151 return err; 152} 153 154static void __exit acpi_ec_sys_exit(void) 155{ 156 debugfs_remove_recursive(acpi_ec_debugfs_dir); 157} 158 159module_init(acpi_ec_sys_init); 160module_exit(acpi_ec_sys_exit); 161