1 /* 2 * OLPC XO-1.5 ebook switch driver 3 * (based on generic ACPI button driver) 4 * 5 * Copyright (C) 2009 Paul Fox <pgf@laptop.org> 6 * Copyright (C) 2010 One Laptop per Child 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or (at 11 * your option) any later version. 12 */ 13 14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 15 16 #include <linux/kernel.h> 17 #include <linux/module.h> 18 #include <linux/init.h> 19 #include <linux/types.h> 20 #include <linux/input.h> 21 #include <acpi/acpi_bus.h> 22 #include <acpi/acpi_drivers.h> 23 24 #define MODULE_NAME "xo15-ebook" 25 26 #define XO15_EBOOK_CLASS MODULE_NAME 27 #define XO15_EBOOK_TYPE_UNKNOWN 0x00 28 #define XO15_EBOOK_NOTIFY_STATUS 0x80 29 30 #define XO15_EBOOK_SUBCLASS "ebook" 31 #define XO15_EBOOK_HID "XO15EBK" 32 #define XO15_EBOOK_DEVICE_NAME "EBook Switch" 33 34 ACPI_MODULE_NAME(MODULE_NAME); 35 36 MODULE_DESCRIPTION("OLPC XO-1.5 ebook switch driver"); 37 MODULE_LICENSE("GPL"); 38 39 static const struct acpi_device_id ebook_device_ids[] = { 40 { XO15_EBOOK_HID, 0 }, 41 { "", 0 }, 42 }; 43 MODULE_DEVICE_TABLE(acpi, ebook_device_ids); 44 45 struct ebook_switch { 46 struct input_dev *input; 47 char phys[32]; /* for input device */ 48 }; 49 50 static int ebook_send_state(struct acpi_device *device) 51 { 52 struct ebook_switch *button = acpi_driver_data(device); 53 unsigned long long state; 54 acpi_status status; 55 56 status = acpi_evaluate_integer(device->handle, "EBK", NULL, &state); 57 if (ACPI_FAILURE(status)) 58 return -EIO; 59 60 /* input layer checks if event is redundant */ 61 input_report_switch(button->input, SW_TABLET_MODE, !state); 62 input_sync(button->input); 63 return 0; 64 } 65 66 static void ebook_switch_notify(struct acpi_device *device, u32 event) 67 { 68 switch (event) { 69 case ACPI_FIXED_HARDWARE_EVENT: 70 case XO15_EBOOK_NOTIFY_STATUS: 71 ebook_send_state(device); 72 break; 73 default: 74 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 75 "Unsupported event [0x%x]\n", event)); 76 break; 77 } 78 } 79 80 static int ebook_switch_resume(struct acpi_device *device) 81 { 82 return ebook_send_state(device); 83 } 84 85 static int ebook_switch_add(struct acpi_device *device) 86 { 87 struct ebook_switch *button; 88 struct input_dev *input; 89 const char *hid = acpi_device_hid(device); 90 char *name, *class; 91 int error; 92 93 button = kzalloc(sizeof(struct ebook_switch), GFP_KERNEL); 94 if (!button) 95 return -ENOMEM; 96 97 device->driver_data = button; 98 99 button->input = input = input_allocate_device(); 100 if (!input) { 101 error = -ENOMEM; 102 goto err_free_button; 103 } 104 105 name = acpi_device_name(device); 106 class = acpi_device_class(device); 107 108 if (strcmp(hid, XO15_EBOOK_HID)) { 109 pr_err("Unsupported hid [%s]\n", hid); 110 error = -ENODEV; 111 goto err_free_input; 112 } 113 114 strcpy(name, XO15_EBOOK_DEVICE_NAME); 115 sprintf(class, "%s/%s", XO15_EBOOK_CLASS, XO15_EBOOK_SUBCLASS); 116 117 snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid); 118 119 input->name = name; 120 input->phys = button->phys; 121 input->id.bustype = BUS_HOST; 122 input->dev.parent = &device->dev; 123 124 input->evbit[0] = BIT_MASK(EV_SW); 125 set_bit(SW_TABLET_MODE, input->swbit); 126 127 error = input_register_device(input); 128 if (error) 129 goto err_free_input; 130 131 ebook_send_state(device); 132 133 if (device->wakeup.flags.valid) { 134 /* Button's GPE is run-wake GPE */ 135 acpi_enable_gpe(device->wakeup.gpe_device, 136 device->wakeup.gpe_number); 137 device_set_wakeup_enable(&device->dev, true); 138 } 139 140 return 0; 141 142 err_free_input: 143 input_free_device(input); 144 err_free_button: 145 kfree(button); 146 return error; 147 } 148 149 static int ebook_switch_remove(struct acpi_device *device, int type) 150 { 151 struct ebook_switch *button = acpi_driver_data(device); 152 153 input_unregister_device(button->input); 154 kfree(button); 155 return 0; 156 } 157 158 static struct acpi_driver xo15_ebook_driver = { 159 .name = MODULE_NAME, 160 .class = XO15_EBOOK_CLASS, 161 .ids = ebook_device_ids, 162 .ops = { 163 .add = ebook_switch_add, 164 .resume = ebook_switch_resume, 165 .remove = ebook_switch_remove, 166 .notify = ebook_switch_notify, 167 }, 168 }; 169 170 static int __init xo15_ebook_init(void) 171 { 172 return acpi_bus_register_driver(&xo15_ebook_driver); 173 } 174 175 static void __exit xo15_ebook_exit(void) 176 { 177 acpi_bus_unregister_driver(&xo15_ebook_driver); 178 } 179 180 module_init(xo15_ebook_init); 181 module_exit(xo15_ebook_exit); 182