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 <linux/acpi.h> 22 23 #define MODULE_NAME "xo15-ebook" 24 25 #define XO15_EBOOK_CLASS MODULE_NAME 26 #define XO15_EBOOK_TYPE_UNKNOWN 0x00 27 #define XO15_EBOOK_NOTIFY_STATUS 0x80 28 29 #define XO15_EBOOK_SUBCLASS "ebook" 30 #define XO15_EBOOK_HID "XO15EBK" 31 #define XO15_EBOOK_DEVICE_NAME "EBook Switch" 32 33 ACPI_MODULE_NAME(MODULE_NAME); 34 35 MODULE_DESCRIPTION("OLPC XO-1.5 ebook switch driver"); 36 MODULE_LICENSE("GPL"); 37 38 static const struct acpi_device_id ebook_device_ids[] = { 39 { XO15_EBOOK_HID, 0 }, 40 { "", 0 }, 41 }; 42 MODULE_DEVICE_TABLE(acpi, ebook_device_ids); 43 44 struct ebook_switch { 45 struct input_dev *input; 46 char phys[32]; /* for input device */ 47 }; 48 49 static int ebook_send_state(struct acpi_device *device) 50 { 51 struct ebook_switch *button = acpi_driver_data(device); 52 unsigned long long state; 53 acpi_status status; 54 55 status = acpi_evaluate_integer(device->handle, "EBK", NULL, &state); 56 if (ACPI_FAILURE(status)) 57 return -EIO; 58 59 /* input layer checks if event is redundant */ 60 input_report_switch(button->input, SW_TABLET_MODE, !state); 61 input_sync(button->input); 62 return 0; 63 } 64 65 static void ebook_switch_notify(struct acpi_device *device, u32 event) 66 { 67 switch (event) { 68 case ACPI_FIXED_HARDWARE_EVENT: 69 case XO15_EBOOK_NOTIFY_STATUS: 70 ebook_send_state(device); 71 break; 72 default: 73 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 74 "Unsupported event [0x%x]\n", event)); 75 break; 76 } 77 } 78 79 #ifdef CONFIG_PM_SLEEP 80 static int ebook_switch_resume(struct device *dev) 81 { 82 return ebook_send_state(to_acpi_device(dev)); 83 } 84 #endif 85 86 static SIMPLE_DEV_PM_OPS(ebook_switch_pm, NULL, ebook_switch_resume); 87 88 static int ebook_switch_add(struct acpi_device *device) 89 { 90 struct ebook_switch *button; 91 struct input_dev *input; 92 const char *hid = acpi_device_hid(device); 93 char *name, *class; 94 int error; 95 96 button = kzalloc(sizeof(struct ebook_switch), GFP_KERNEL); 97 if (!button) 98 return -ENOMEM; 99 100 device->driver_data = button; 101 102 button->input = input = input_allocate_device(); 103 if (!input) { 104 error = -ENOMEM; 105 goto err_free_button; 106 } 107 108 name = acpi_device_name(device); 109 class = acpi_device_class(device); 110 111 if (strcmp(hid, XO15_EBOOK_HID)) { 112 pr_err("Unsupported hid [%s]\n", hid); 113 error = -ENODEV; 114 goto err_free_input; 115 } 116 117 strcpy(name, XO15_EBOOK_DEVICE_NAME); 118 sprintf(class, "%s/%s", XO15_EBOOK_CLASS, XO15_EBOOK_SUBCLASS); 119 120 snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid); 121 122 input->name = name; 123 input->phys = button->phys; 124 input->id.bustype = BUS_HOST; 125 input->dev.parent = &device->dev; 126 127 input->evbit[0] = BIT_MASK(EV_SW); 128 set_bit(SW_TABLET_MODE, input->swbit); 129 130 error = input_register_device(input); 131 if (error) 132 goto err_free_input; 133 134 ebook_send_state(device); 135 136 if (device->wakeup.flags.valid) { 137 /* Button's GPE is run-wake GPE */ 138 acpi_enable_gpe(device->wakeup.gpe_device, 139 device->wakeup.gpe_number); 140 device_set_wakeup_enable(&device->dev, true); 141 } 142 143 return 0; 144 145 err_free_input: 146 input_free_device(input); 147 err_free_button: 148 kfree(button); 149 return error; 150 } 151 152 static int ebook_switch_remove(struct acpi_device *device) 153 { 154 struct ebook_switch *button = acpi_driver_data(device); 155 156 input_unregister_device(button->input); 157 kfree(button); 158 return 0; 159 } 160 161 static struct acpi_driver xo15_ebook_driver = { 162 .name = MODULE_NAME, 163 .class = XO15_EBOOK_CLASS, 164 .ids = ebook_device_ids, 165 .ops = { 166 .add = ebook_switch_add, 167 .remove = ebook_switch_remove, 168 .notify = ebook_switch_notify, 169 }, 170 .drv.pm = &ebook_switch_pm, 171 }; 172 module_acpi_driver(xo15_ebook_driver); 173