swh:1:snp:c2847dfd741eae21606027cf29250d1ebcd63fb4
Tip revision: 7111951b8d4973bda27ff663f2cf18b663d15b48 authored by Linus Torvalds on 29 March 2020, 22:25:41 UTC
Linux 5.6
Linux 5.6
Tip revision: 7111951
hid-google-hammer.c
// 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");