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