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