Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 622 insertions, 0 deletions

diff --git a/drivers/hid/hid-google-hammer.c b/drivers/hid/hid-google-hammer.c
new file mode 100644
index 000000000..c99c3c0d4
--- /dev/null
+++ b/drivers/hid/hid-google-hammer.c
@@ -0,0 +1,622 @@
+// 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/input/vivaldi-fmap.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_ec_proto.h>
+#include <linux/platform_device.h>
+#include <linux/unaligned.h>
+
+#include "hid-ids.h"
+#include "hid-vivaldi-common.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_flex(*msg, data, max(sizeof(u32), sizeof(*params)));
+	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 void 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);
+}
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id cbas_ec_acpi_ids[] = {
+	{ "GOOG000B", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, cbas_ec_acpi_ids);
+#endif
+
+#ifdef CONFIG_OF
+static const struct of_device_id cbas_ec_of_match[] = {
+	{ .compatible = "google,cros-cbas" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, cbas_ec_of_match);
+#endif
+
+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),
+		.of_match_table = of_match_ptr(cbas_ec_of_match),
+		.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;
+
+	kbd_backlight = devm_kzalloc(&hdev->dev, 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);
+
+	return devm_led_classdev_register(&hdev->dev, &kbd_backlight->cdev);
+}
+
+#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_folded_event(struct hid_device *hdev)
+{
+	return !!hid_find_field(hdev, HID_INPUT_REPORT,
+				HID_GD_KEYBOARD, HID_USAGE_KBD_FOLDED);
+}
+
+static bool hammer_has_backlight_control(struct hid_device *hdev)
+{
+	return !!hid_find_field(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 void hammer_stop(void *hdev)
+{
+	hid_hw_stop(hdev);
+}
+
+static int hammer_probe(struct hid_device *hdev,
+			const struct hid_device_id *id)
+{
+	struct vivaldi_data *vdata;
+	int error;
+
+	vdata = devm_kzalloc(&hdev->dev, sizeof(*vdata), GFP_KERNEL);
+	if (!vdata)
+		return -ENOMEM;
+
+	hid_set_drvdata(hdev, vdata);
+
+	error = hid_parse(hdev);
+	if (error)
+		return error;
+
+	error = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+	if (error)
+		return error;
+
+	error = devm_add_action_or_reset(&hdev->dev, hammer_stop, hdev);
+	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);
+	}
+
+	/* Unregistering LEDs and stopping the hardware is done via devm */
+}
+
+static const struct hid_device_id hammer_devices[] = {
+	{ HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
+		     USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_DON) },
+	{ HID_DEVICE(BUS_USB, HID_GROUP_VIVALDI,
+		     USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_EEL) },
+	{ 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_JEWEL) },
+	{ 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,
+	.feature_mapping = vivaldi_feature_mapping,
+	.input_mapping = hammer_input_mapping,
+	.event = hammer_event,
+	.driver = {
+		.dev_groups = vivaldi_attribute_groups,
+	},
+};
+
+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_DESCRIPTION("HID driver for Google Hammer device.");
+MODULE_LICENSE("GPL");