// SPDX-License-Identifier: GPL-2.0+ /* * HID driver for Google Hammer device. * * Copyright (c) 2017 Google Inc. * Author: Wei-Ning Huang <wnhuang@google.com> */ /* * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or (at your option) * any later version. */ #include <linux/acpi.h> #include <linux/hid.h> #include <linux/leds.h> #include <linux/module.h> #include <linux/platform_data/cros_ec_commands.h> #include <linux/platform_data/cros_ec_proto.h> #include <linux/platform_device.h> #include <linux/pm_wakeup.h> #include <asm/unaligned.h> #include "hid-ids.h" /* * C(hrome)B(ase)A(ttached)S(witch) - switch exported by Chrome EC and reporting * state of the "Whiskers" base - attached or detached. Whiskers USB device also * reports position of the keyboard - folded or not. Combining base state and * position allows us to generate proper "Tablet mode" events. */ struct cbas_ec { struct device *dev; /* The platform device (EC) */ struct input_dev *input; bool base_present; bool base_folded; struct notifier_block notifier; }; static struct cbas_ec cbas_ec; static DEFINE_SPINLOCK(cbas_ec_lock); static DEFINE_MUTEX(cbas_ec_reglock); static bool cbas_parse_base_state(const void *data) { u32 switches = get_unaligned_le32(data); return !!(switches & BIT(EC_MKBP_BASE_ATTACHED)); } static int cbas_ec_query_base(struct cros_ec_device *ec_dev, bool get_state, bool *state) { struct ec_params_mkbp_info *params; struct cros_ec_command *msg; int ret; msg = kzalloc(sizeof(*msg) + max(sizeof(u32), sizeof(*params)), GFP_KERNEL); if (!msg) return -ENOMEM; msg->command = EC_CMD_MKBP_INFO; msg->version = 1; msg->outsize = sizeof(*params); msg->insize = sizeof(u32); params = (struct ec_params_mkbp_info *)msg->data; params->info_type = get_state ? EC_MKBP_INFO_CURRENT : EC_MKBP_INFO_SUPPORTED; params->event_type = EC_MKBP_EVENT_SWITCH; ret = cros_ec_cmd_xfer_status(ec_dev, msg); if (ret >= 0) { if (ret != sizeof(u32)) { dev_warn(ec_dev->dev, "wrong result size: %d != %zu\n", ret, sizeof(u32)); ret = -EPROTO; } else { *state = cbas_parse_base_state(msg->data); ret = 0; } } kfree(msg); return ret; } static int cbas_ec_notify(struct notifier_block *nb, unsigned long queued_during_suspend, void *_notify) { struct cros_ec_device *ec = _notify; unsigned long flags; bool base_present; if (ec->event_data.event_type == EC_MKBP_EVENT_SWITCH) { base_present = cbas_parse_base_state( &ec->event_data.data.switches); dev_dbg(cbas_ec.dev, "%s: base: %d\n", __func__, base_present); if (device_may_wakeup(cbas_ec.dev) || !queued_during_suspend) { pm_wakeup_event(cbas_ec.dev, 0); spin_lock_irqsave(&cbas_ec_lock, flags); /* * While input layer dedupes the events, we do not want * to disrupt the state reported by the base by * overriding it with state reported by the LID. Only * report changes, as we assume that on attach the base * is not folded. */ if (base_present != cbas_ec.base_present) { input_report_switch(cbas_ec.input, SW_TABLET_MODE, !base_present); input_sync(cbas_ec.input); cbas_ec.base_present = base_present; } spin_unlock_irqrestore(&cbas_ec_lock, flags); } } return NOTIFY_OK; } static __maybe_unused int cbas_ec_resume(struct device *dev) { struct cros_ec_device *ec = dev_get_drvdata(dev->parent); bool base_present; int error; error = cbas_ec_query_base(ec, true, &base_present); if (error) { dev_warn(dev, "failed to fetch base state on resume: %d\n", error); } else { spin_lock_irq(&cbas_ec_lock); cbas_ec.base_present = base_present; /* * Only report if base is disconnected. If base is connected, * it will resend its state on resume, and we'll update it * in hammer_event(). */ if (!cbas_ec.base_present) { input_report_switch(cbas_ec.input, SW_TABLET_MODE, 1); input_sync(cbas_ec.input); } spin_unlock_irq(&cbas_ec_lock); } return 0; } static SIMPLE_DEV_PM_OPS(cbas_ec_pm_ops, NULL, cbas_ec_resume); static void cbas_ec_set_input(struct input_dev *input) { /* Take the lock so hammer_event() does not race with us here */ spin_lock_irq(&cbas_ec_lock); cbas_ec.input = input; spin_unlock_irq(&cbas_ec_lock); } static int __cbas_ec_probe(struct platform_device *pdev) { struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent); struct input_dev *input; bool base_supported; int error; error = cbas_ec_query_base(ec, false, &base_supported); if (error) return error; if (!base_supported) return -ENXIO; input = devm_input_allocate_device(&pdev->dev); if (!input) return -ENOMEM; input->name = "Whiskers Tablet Mode Switch"; input->id.bustype = BUS_HOST; input_set_capability(input, EV_SW, SW_TABLET_MODE); error = input_register_device(input); if (error) { dev_err(&pdev->dev, "cannot register input device: %d\n", error); return error; } /* Seed the state */ error = cbas_ec_query_base(ec, true, &cbas_ec.base_present); if (error) { dev_err(&pdev->dev, "cannot query base state: %d\n", error); return error; } if (!cbas_ec.base_present) cbas_ec.base_folded = false; dev_dbg(&pdev->dev, "%s: base: %d, folded: %d\n", __func__, cbas_ec.base_present, cbas_ec.base_folded); input_report_switch(input, SW_TABLET_MODE, !cbas_ec.base_present || cbas_ec.base_folded); cbas_ec_set_input(input); cbas_ec.dev = &pdev->dev; cbas_ec.notifier.notifier_call = cbas_ec_notify; error = blocking_notifier_chain_register(&ec->event_notifier, &cbas_ec.notifier); if (error) { dev_err(&pdev->dev, "cannot register notifier: %d\n", error); cbas_ec_set_input(NULL); return error; } device_init_wakeup(&pdev->dev, true); return 0; } static int cbas_ec_probe(struct platform_device *pdev) { int retval; mutex_lock(&cbas_ec_reglock); if (cbas_ec.input) { retval = -EBUSY; goto out; } retval = __cbas_ec_probe(pdev); out: mutex_unlock(&cbas_ec_reglock); return retval; } static int cbas_ec_remove(struct platform_device *pdev) { struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent); mutex_lock(&cbas_ec_reglock); blocking_notifier_chain_unregister(&ec->event_notifier, &cbas_ec.notifier); cbas_ec_set_input(NULL); mutex_unlock(&cbas_ec_reglock); return 0; } static const struct acpi_device_id cbas_ec_acpi_ids[] = { { "GOOG000B", 0 }, { } }; MODULE_DEVICE_TABLE(acpi, cbas_ec_acpi_ids); static struct platform_driver cbas_ec_driver = { .probe = cbas_ec_probe, .remove = cbas_ec_remove, .driver = { .name = "cbas_ec", .acpi_match_table = ACPI_PTR(cbas_ec_acpi_ids), .pm = &cbas_ec_pm_ops, }, }; #define MAX_BRIGHTNESS 100 struct hammer_kbd_leds { struct led_classdev cdev; struct hid_device *hdev; u8 buf[2] ____cacheline_aligned; }; static int hammer_kbd_brightness_set_blocking(struct led_classdev *cdev, enum led_brightness br) { struct hammer_kbd_leds *led = container_of(cdev, struct hammer_kbd_leds, cdev); int ret; led->buf[0] = 0; led->buf[1] = br; /* * Request USB HID device to be in Full On mode, so that sending * hardware output report and hardware raw request won't fail. */ ret = hid_hw_power(led->hdev, PM_HINT_FULLON); if (ret < 0) { hid_err(led->hdev, "failed: device not resumed %d\n", ret); return ret; } ret = hid_hw_output_report(led->hdev, led->buf, sizeof(led->buf)); if (ret == -ENOSYS) ret = hid_hw_raw_request(led->hdev, 0, led->buf, sizeof(led->buf), HID_OUTPUT_REPORT, HID_REQ_SET_REPORT); if (ret < 0) hid_err(led->hdev, "failed to set keyboard backlight: %d\n", ret); /* Request USB HID device back to Normal Mode. */ hid_hw_power(led->hdev, PM_HINT_NORMAL); return ret; } static int hammer_register_leds(struct hid_device *hdev) { struct hammer_kbd_leds *kbd_backlight; int error; kbd_backlight = kzalloc(sizeof(*kbd_backlight), GFP_KERNEL); if (!kbd_backlight) return -ENOMEM; kbd_backlight->hdev = hdev; kbd_backlight->cdev.name = "hammer::kbd_backlight"; kbd_backlight->cdev.max_brightness = MAX_BRIGHTNESS; kbd_backlight->cdev.brightness_set_blocking = hammer_kbd_brightness_set_blocking; kbd_backlight->cdev.flags = LED_HW_PLUGGABLE; /* Set backlight to 0% initially. */ hammer_kbd_brightness_set_blocking(&kbd_backlight->cdev, 0); error = led_classdev_register(&hdev->dev, &kbd_backlight->cdev); if (error) goto err_free_mem; hid_set_drvdata(hdev, kbd_backlight); return 0; err_free_mem: kfree(kbd_backlight); return error; } static void hammer_unregister_leds(struct hid_device *hdev) { struct hammer_kbd_leds *kbd_backlight = hid_get_drvdata(hdev); if (kbd_backlight) { led_classdev_unregister(&kbd_backlight->cdev); kfree(kbd_backlight); } } #define HID_UP_GOOGLEVENDOR 0xffd10000 #define HID_VD_KBD_FOLDED 0x00000019 #define HID_USAGE_KBD_FOLDED (HID_UP_GOOGLEVENDOR | HID_VD_KBD_FOLDED) /* HID usage for keyboard backlight (Alphanumeric display brightness) */ #define HID_AD_BRIGHTNESS 0x00140046 static int hammer_input_mapping(struct hid_device *hdev, struct hid_input *hi, struct hid_field *field, struct hid_usage *usage, unsigned long **bit, int *max) { if (usage->hid == HID_USAGE_KBD_FOLDED) { /* * We do not want to have this usage mapped as it will get * mixed in with "base attached" signal and delivered over * separate input device for tablet switch mode. */ return -1; } return 0; } static int hammer_event(struct hid_device *hid, struct hid_field *field, struct hid_usage *usage, __s32 value) { unsigned long flags; if (usage->hid == HID_USAGE_KBD_FOLDED) { spin_lock_irqsave(&cbas_ec_lock, flags); /* * If we are getting events from Whiskers that means that it * is attached to the lid. */ cbas_ec.base_present = true; cbas_ec.base_folded = value; hid_dbg(hid, "%s: base: %d, folded: %d\n", __func__, cbas_ec.base_present, cbas_ec.base_folded); if (cbas_ec.input) { input_report_switch(cbas_ec.input, SW_TABLET_MODE, value); input_sync(cbas_ec.input); } spin_unlock_irqrestore(&cbas_ec_lock, flags); return 1; /* We handled this event */ } return 0; } static bool hammer_has_usage(struct hid_device *hdev, unsigned int report_type, unsigned application, unsigned usage) { struct hid_report_enum *re = &hdev->report_enum[report_type]; struct hid_report *report; int i, j; list_for_each_entry(report, &re->report_list, list) { if (report->application != application) continue; for (i = 0; i < report->maxfield; i++) { struct hid_field *field = report->field[i]; for (j = 0; j < field->maxusage; j++) if (field->usage[j].hid == usage) return true; } } return false; } static bool hammer_has_folded_event(struct hid_device *hdev) { return hammer_has_usage(hdev, HID_INPUT_REPORT, HID_GD_KEYBOARD, HID_USAGE_KBD_FOLDED); } static bool hammer_has_backlight_control(struct hid_device *hdev) { return hammer_has_usage(hdev, HID_OUTPUT_REPORT, HID_GD_KEYBOARD, HID_AD_BRIGHTNESS); } static int hammer_probe(struct hid_device *hdev, const struct hid_device_id *id) { int error; error = hid_parse(hdev); if (error) return error; error = hid_hw_start(hdev, HID_CONNECT_DEFAULT); if (error) return error; /* * We always want to poll for, and handle tablet mode events from * devices that have folded usage, even when nobody has opened the input * device. This also prevents the hid core from dropping early tablet * mode events from the device. */ if (hammer_has_folded_event(hdev)) { hdev->quirks |= HID_QUIRK_ALWAYS_POLL; error = hid_hw_open(hdev); if (error) return error; } if (hammer_has_backlight_control(hdev)) { error = hammer_register_leds(hdev); if (error) hid_warn(hdev, "Failed to register keyboard backlight: %d\n", error); } return 0; } static void hammer_remove(struct hid_device *hdev) { unsigned long flags; if (hammer_has_folded_event(hdev)) { hid_hw_close(hdev); /* * If we are disconnecting then most likely Whiskers is * being removed. Even if it is not removed, without proper * keyboard we should not stay in clamshell mode. * * The reason for doing it here and not waiting for signal * from EC, is that on some devices there are high leakage * on Whiskers pins and we do not detect disconnect reliably, * resulting in devices being stuck in clamshell mode. */ spin_lock_irqsave(&cbas_ec_lock, flags); if (cbas_ec.input && cbas_ec.base_present) { input_report_switch(cbas_ec.input, SW_TABLET_MODE, 1); input_sync(cbas_ec.input); } cbas_ec.base_present = false; spin_unlock_irqrestore(&cbas_ec_lock, flags); } hammer_unregister_leds(hdev); hid_hw_stop(hdev); } static const struct hid_device_id hammer_devices[] = { { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_HAMMER) }, { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_MAGNEMITE) }, { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_MASTERBALL) }, { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_MOONBALL) }, { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STAFF) }, { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_WAND) }, { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_WHISKERS) }, { } }; MODULE_DEVICE_TABLE(hid, hammer_devices); static struct hid_driver hammer_driver = { .name = "hammer", .id_table = hammer_devices, .probe = hammer_probe, .remove = hammer_remove, .input_mapping = hammer_input_mapping, .event = hammer_event, }; static int __init hammer_init(void) { int error; error = platform_driver_register(&cbas_ec_driver); if (error) return error; error = hid_register_driver(&hammer_driver); if (error) { platform_driver_unregister(&cbas_ec_driver); return error; } return 0; } module_init(hammer_init); static void __exit hammer_exit(void) { hid_unregister_driver(&hammer_driver); platform_driver_unregister(&cbas_ec_driver); } module_exit(hammer_exit); MODULE_LICENSE("GPL");