| 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 | struct sysdev_class acpi_ec_sysdev_class = { |
| 28 | .name = "ec", |
| 29 | }; |
| 30 | |
| 31 | static struct dentry *acpi_ec_debugfs_dir; |
| 32 | |
| 33 | static int acpi_ec_open_io(struct inode *i, struct file *f) |
| 34 | { |
| 35 | f->private_data = i->i_private; |
| 36 | return 0; |
| 37 | } |
| 38 | |
| 39 | static 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 | |
| 68 | static 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 | |
| 99 | static 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 | .llseek = default_llseek, |
| 105 | }; |
| 106 | |
| 107 | int acpi_ec_add_debugfs(struct acpi_ec *ec, unsigned int ec_device_count) |
| 108 | { |
| 109 | struct dentry *dev_dir; |
| 110 | char name[64]; |
| 111 | mode_t mode = 0400; |
| 112 | |
| 113 | if (ec_device_count == 0) { |
| 114 | acpi_ec_debugfs_dir = debugfs_create_dir("ec", NULL); |
| 115 | if (!acpi_ec_debugfs_dir) |
| 116 | return -ENOMEM; |
| 117 | } |
| 118 | |
| 119 | sprintf(name, "ec%u", ec_device_count); |
| 120 | dev_dir = debugfs_create_dir(name, acpi_ec_debugfs_dir); |
| 121 | if (!dev_dir) { |
| 122 | if (ec_device_count != 0) |
| 123 | goto error; |
| 124 | return -ENOMEM; |
| 125 | } |
| 126 | |
| 127 | if (!debugfs_create_x32("gpe", 0444, dev_dir, (u32 *)&first_ec->gpe)) |
| 128 | goto error; |
| 129 | if (!debugfs_create_bool("use_global_lock", 0444, dev_dir, |
| 130 | (u32 *)&first_ec->global_lock)) |
| 131 | goto error; |
| 132 | |
| 133 | if (write_support) |
| 134 | mode = 0600; |
| 135 | if (!debugfs_create_file("io", mode, dev_dir, ec, &acpi_ec_io_ops)) |
| 136 | goto error; |
| 137 | |
| 138 | return 0; |
| 139 | |
| 140 | error: |
| 141 | debugfs_remove_recursive(acpi_ec_debugfs_dir); |
| 142 | return -ENOMEM; |
| 143 | } |
| 144 | |
| 145 | static int __init acpi_ec_sys_init(void) |
| 146 | { |
| 147 | int err = 0; |
| 148 | if (first_ec) |
| 149 | err = acpi_ec_add_debugfs(first_ec, 0); |
| 150 | else |
| 151 | err = -ENODEV; |
| 152 | return err; |
| 153 | } |
| 154 | |
| 155 | static void __exit acpi_ec_sys_exit(void) |
| 156 | { |
| 157 | debugfs_remove_recursive(acpi_ec_debugfs_dir); |
| 158 | } |
| 159 | |
| 160 | module_init(acpi_ec_sys_init); |
| 161 | module_exit(acpi_ec_sys_exit); |