1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * OLPC XO-1.5 ebook switch driver 4 * (based on generic ACPI button driver) 5 * 6 * Copyright (C) 2009 Paul Fox <pgf@laptop.org> 7 * Copyright (C) 2010 One Laptop per Child 8 */ 9 10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 11 12 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/init.h> 15 #include <linux/types.h> 16 #include <linux/input.h> 17 #include <linux/acpi.h> 18 19 #define MODULE_NAME "xo15-ebook" 20 21 #define XO15_EBOOK_CLASS MODULE_NAME 22 #define XO15_EBOOK_TYPE_UNKNOWN 0x00 23 #define XO15_EBOOK_NOTIFY_STATUS 0x80 24 25 #define XO15_EBOOK_SUBCLASS "ebook" 26 #define XO15_EBOOK_HID "XO15EBK" 27 #define XO15_EBOOK_DEVICE_NAME "EBook Switch" 28 29 MODULE_DESCRIPTION("OLPC XO-1.5 ebook switch driver"); 30 MODULE_LICENSE("GPL"); 31 32 static const struct acpi_device_id ebook_device_ids[] = { 33 { XO15_EBOOK_HID, 0 }, 34 { "", 0 }, 35 }; 36 MODULE_DEVICE_TABLE(acpi, ebook_device_ids); 37 38 struct ebook_switch { 39 struct input_dev *input; 40 char phys[32]; /* for input device */ 41 }; 42 43 static int ebook_send_state(struct acpi_device *device) 44 { 45 struct ebook_switch *button = acpi_driver_data(device); 46 unsigned long long state; 47 acpi_status status; 48 49 status = acpi_evaluate_integer(device->handle, "EBK", NULL, &state); 50 if (ACPI_FAILURE(status)) 51 return -EIO; 52 53 /* input layer checks if event is redundant */ 54 input_report_switch(button->input, SW_TABLET_MODE, !state); 55 input_sync(button->input); 56 return 0; 57 } 58 59 static void ebook_switch_notify(struct acpi_device *device, u32 event) 60 { 61 switch (event) { 62 case ACPI_FIXED_HARDWARE_EVENT: 63 case XO15_EBOOK_NOTIFY_STATUS: 64 ebook_send_state(device); 65 break; 66 default: 67 acpi_handle_debug(device->handle, 68 "Unsupported event [0x%x]\n", event); 69 break; 70 } 71 } 72 73 #ifdef CONFIG_PM_SLEEP 74 static int ebook_switch_resume(struct device *dev) 75 { 76 return ebook_send_state(to_acpi_device(dev)); 77 } 78 #endif 79 80 static SIMPLE_DEV_PM_OPS(ebook_switch_pm, NULL, ebook_switch_resume); 81 82 static int ebook_switch_add(struct acpi_device *device) 83 { 84 const struct acpi_device_id *id; 85 struct ebook_switch *button; 86 struct input_dev *input; 87 int error; 88 89 button = kzalloc(sizeof(struct ebook_switch), GFP_KERNEL); 90 if (!button) 91 return -ENOMEM; 92 93 device->driver_data = button; 94 95 button->input = input = input_allocate_device(); 96 if (!input) { 97 error = -ENOMEM; 98 goto err_free_button; 99 } 100 101 id = acpi_match_acpi_device(ebook_device_ids, device); 102 if (!id) { 103 dev_err(&device->dev, "Unsupported hid\n"); 104 error = -ENODEV; 105 goto err_free_input; 106 } 107 108 strscpy(acpi_device_name(device), XO15_EBOOK_DEVICE_NAME); 109 strscpy(acpi_device_class(device), XO15_EBOOK_CLASS "/" XO15_EBOOK_SUBCLASS); 110 111 snprintf(button->phys, sizeof(button->phys), "%s/button/input0", id->id); 112 113 input->name = acpi_device_name(device); 114 input->phys = button->phys; 115 input->id.bustype = BUS_HOST; 116 input->dev.parent = &device->dev; 117 118 input->evbit[0] = BIT_MASK(EV_SW); 119 set_bit(SW_TABLET_MODE, input->swbit); 120 121 error = input_register_device(input); 122 if (error) 123 goto err_free_input; 124 125 ebook_send_state(device); 126 127 if (device->wakeup.flags.valid) { 128 /* Button's GPE is run-wake GPE */ 129 acpi_enable_gpe(device->wakeup.gpe_device, 130 device->wakeup.gpe_number); 131 device_set_wakeup_enable(&device->dev, true); 132 } 133 134 return 0; 135 136 err_free_input: 137 input_free_device(input); 138 err_free_button: 139 kfree(button); 140 return error; 141 } 142 143 static void ebook_switch_remove(struct acpi_device *device) 144 { 145 struct ebook_switch *button = acpi_driver_data(device); 146 147 input_unregister_device(button->input); 148 kfree(button); 149 } 150 151 static struct acpi_driver xo15_ebook_driver = { 152 .name = MODULE_NAME, 153 .class = XO15_EBOOK_CLASS, 154 .ids = ebook_device_ids, 155 .ops = { 156 .add = ebook_switch_add, 157 .remove = ebook_switch_remove, 158 .notify = ebook_switch_notify, 159 }, 160 .drv.pm = &ebook_switch_pm, 161 }; 162 module_acpi_driver(xo15_ebook_driver); 163