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