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 ssize_t acpi_ec_read_io(struct file *f, char __user *buf, 31 size_t count, loff_t *off) 32 { 33 /* Use this if support reading/writing multiple ECs exists in ec.c: 34 * struct acpi_ec *ec = ((struct seq_file *)f->private_data)->private; 35 */ 36 unsigned int size = EC_SPACE_SIZE; 37 u8 *data = (u8 *) buf; 38 loff_t init_off = *off; 39 int err = 0; 40 41 if (*off >= size) 42 return 0; 43 if (*off + count >= size) { 44 size -= *off; 45 count = size; 46 } else 47 size = count; 48 49 while (size) { 50 err = ec_read(*off, &data[*off - init_off]); 51 if (err) 52 return err; 53 *off += 1; 54 size--; 55 } 56 return count; 57 } 58 59 static ssize_t acpi_ec_write_io(struct file *f, const char __user *buf, 60 size_t count, loff_t *off) 61 { 62 /* Use this if support reading/writing multiple ECs exists in ec.c: 63 * struct acpi_ec *ec = ((struct seq_file *)f->private_data)->private; 64 */ 65 66 unsigned int size = count; 67 loff_t init_off = *off; 68 u8 *data = (u8 *) buf; 69 int err = 0; 70 71 if (*off >= EC_SPACE_SIZE) 72 return 0; 73 if (*off + count >= EC_SPACE_SIZE) { 74 size = EC_SPACE_SIZE - *off; 75 count = size; 76 } 77 78 while (size) { 79 u8 byte_write = data[*off - init_off]; 80 err = ec_write(*off, byte_write); 81 if (err) 82 return err; 83 84 *off += 1; 85 size--; 86 } 87 return count; 88 } 89 90 static const struct file_operations acpi_ec_io_ops = { 91 .owner = THIS_MODULE, 92 .open = simple_open, 93 .read = acpi_ec_read_io, 94 .write = acpi_ec_write_io, 95 .llseek = default_llseek, 96 }; 97 98 int acpi_ec_add_debugfs(struct acpi_ec *ec, unsigned int ec_device_count) 99 { 100 struct dentry *dev_dir; 101 char name[64]; 102 umode_t mode = 0400; 103 104 if (ec_device_count == 0) { 105 acpi_ec_debugfs_dir = debugfs_create_dir("ec", NULL); 106 if (!acpi_ec_debugfs_dir) 107 return -ENOMEM; 108 } 109 110 sprintf(name, "ec%u", ec_device_count); 111 dev_dir = debugfs_create_dir(name, acpi_ec_debugfs_dir); 112 if (!dev_dir) { 113 if (ec_device_count != 0) 114 goto error; 115 return -ENOMEM; 116 } 117 118 if (!debugfs_create_x32("gpe", 0444, dev_dir, (u32 *)&first_ec->gpe)) 119 goto error; 120 if (!debugfs_create_bool("use_global_lock", 0444, dev_dir, 121 (u32 *)&first_ec->global_lock)) 122 goto error; 123 124 if (write_support) 125 mode = 0600; 126 if (!debugfs_create_file("io", mode, dev_dir, ec, &acpi_ec_io_ops)) 127 goto error; 128 129 return 0; 130 131 error: 132 debugfs_remove_recursive(acpi_ec_debugfs_dir); 133 return -ENOMEM; 134 } 135 136 static int __init acpi_ec_sys_init(void) 137 { 138 int err = 0; 139 if (first_ec) 140 err = acpi_ec_add_debugfs(first_ec, 0); 141 else 142 err = -ENODEV; 143 return err; 144 } 145 146 static void __exit acpi_ec_sys_exit(void) 147 { 148 debugfs_remove_recursive(acpi_ec_debugfs_dir); 149 } 150 151 module_init(acpi_ec_sys_init); 152 module_exit(acpi_ec_sys_exit); 153