1 files changed, 645 insertions, 0 deletions

diff --git a/drivers/hid/hid-google-hammer.c b/drivers/hid/hid-google-hammer.c
new file mode 100644
index 0000000000..c6bdb9c4ef
--- /dev/null
+++ b/drivers/hid/hid-google-hammer.c
@@ -0,0 +1,645 @@
+// 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/pm_wakeup.h>
+#include <asm/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(struct_size(msg, data, 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);
+
+#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_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 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(&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_LICENSE("GPL");