| // 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 void hammer_folded_event(struct hid_device *hdev, bool folded) |
| { |
| unsigned long flags; |
| |
| 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 = folded; |
| hid_dbg(hdev, "%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, folded); |
| input_sync(cbas_ec.input); |
| } |
| |
| spin_unlock_irqrestore(&cbas_ec_lock, flags); |
| } |
| |
| static int hammer_event(struct hid_device *hid, struct hid_field *field, |
| struct hid_usage *usage, __s32 value) |
| { |
| if (usage->hid == HID_USAGE_KBD_FOLDED) { |
| hammer_folded_event(hid, value); |
| 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 void hammer_get_folded_state(struct hid_device *hdev) |
| { |
| struct hid_report *report; |
| char *buf; |
| int len, rlen; |
| int a; |
| |
| report = hdev->report_enum[HID_INPUT_REPORT].report_id_hash[0x0]; |
| |
| if (!report || report->maxfield < 1) |
| return; |
| |
| len = hid_report_len(report) + 1; |
| |
| buf = kmalloc(len, GFP_KERNEL); |
| if (!buf) |
| return; |
| |
| rlen = hid_hw_raw_request(hdev, report->id, buf, len, report->type, HID_REQ_GET_REPORT); |
| |
| if (rlen != len) { |
| hid_warn(hdev, "Unable to read base folded state: %d (expected %d)\n", rlen, len); |
| goto out; |
| } |
| |
| for (a = 0; a < report->maxfield; a++) { |
| struct hid_field *field = report->field[a]; |
| |
| if (field->usage->hid == HID_USAGE_KBD_FOLDED) { |
| u32 value = hid_field_extract(hdev, buf+1, |
| field->report_offset, field->report_size); |
| |
| hammer_folded_event(hdev, value); |
| break; |
| } |
| } |
| |
| out: |
| kfree(buf); |
| } |
| |
| 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; |
| |
| hammer_get_folded_state(hdev); |
| } |
| |
| 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"); |