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 struct ebook_switch *button; 85 struct input_dev *input; 86 const char *hid = acpi_device_hid(device); 87 char *name, *class; 88 int error; 89 90 button = kzalloc(sizeof(struct ebook_switch), GFP_KERNEL); 91 if (!button) 92 return -ENOMEM; 93 94 device->driver_data = button; 95 96 button->input = input = input_allocate_device(); 97 if (!input) { 98 error = -ENOMEM; 99 goto err_free_button; 100 } 101 102 name = acpi_device_name(device); 103 class = acpi_device_class(device); 104 105 if (strcmp(hid, XO15_EBOOK_HID)) { 106 pr_err("Unsupported hid [%s]\n", hid); 107 error = -ENODEV; 108 goto err_free_input; 109 } 110 111 strcpy(name, XO15_EBOOK_DEVICE_NAME); 112 sprintf(class, "%s/%s", XO15_EBOOK_CLASS, XO15_EBOOK_SUBCLASS); 113 114 snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid); 115 116 input->name = name; 117 input->phys = button->phys; 118 input->id.bustype = BUS_HOST; 119 input->dev.parent = &device->dev; 120 121 input->evbit[0] = BIT_MASK(EV_SW); 122 set_bit(SW_TABLET_MODE, input->swbit); 123 124 error = input_register_device(input); 125 if (error) 126 goto err_free_input; 127 128 ebook_send_state(device); 129 130 if (device->wakeup.flags.valid) { 131 /* Button's GPE is run-wake GPE */ 132 acpi_enable_gpe(device->wakeup.gpe_device, 133 device->wakeup.gpe_number); 134 device_set_wakeup_enable(&device->dev, true); 135 } 136 137 return 0; 138 139 err_free_input: 140 input_free_device(input); 141 err_free_button: 142 kfree(button); 143 return error; 144 } 145 146 static void ebook_switch_remove(struct acpi_device *device) 147 { 148 struct ebook_switch *button = acpi_driver_data(device); 149 150 input_unregister_device(button->input); 151 kfree(button); 152 } 153 154 static struct acpi_driver xo15_ebook_driver = { 155 .name = MODULE_NAME, 156 .class = XO15_EBOOK_CLASS, 157 .ids = ebook_device_ids, 158 .ops = { 159 .add = ebook_switch_add, 160 .remove = ebook_switch_remove, 161 .notify = ebook_switch_notify, 162 }, 163 .drv.pm = &ebook_switch_pm, 164 }; 165 module_acpi_driver(xo15_ebook_driver); 166