Input: add a driver to support Hyper-V synthetic keyboard (aed06b9c) · Commits · e / devices / android_kernel_oneplus_sm8150

drivers/input/serio/Kconfig

+10 −0

Original line number	Diff line number	Diff line
		@@ -267,4 +267,14 @@ config SERIO_OLPC_APSP
		To compile this driver as a module, choose M here: the module will
		be called olpc_apsp.

		config HYPERV_KEYBOARD
		tristate "Microsoft Synthetic Keyboard driver"
		depends on HYPERV
		default HYPERV
		help
		Select this option to enable the Hyper-V Keyboard driver.

		To compile this driver as a module, choose M here: the module will
		be called hyperv_keyboard.

		endif

drivers/input/serio/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -28,3 +28,4 @@ obj-$(CONFIG_SERIO_ALTERA_PS2) += altera_ps2.o
		obj-$(CONFIG_SERIO_ARC_PS2) += arc_ps2.o
		obj-$(CONFIG_SERIO_APBPS2) += apbps2.o
		obj-$(CONFIG_SERIO_OLPC_APSP) += olpc_apsp.o
		obj-$(CONFIG_HYPERV_KEYBOARD) += hyperv-keyboard.o

drivers/input/serio/hyperv-keyboard.c

0 → 100644

+437 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (c) 2013, Microsoft Corporation.
		*
		* This program is free software; you can redistribute it and/or modify it
		* under the terms and conditions of the GNU General Public License,
		* version 2, as published by the Free Software Foundation.
		*
		* This program is distributed in the hope it will be useful, but WITHOUT
		* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
		* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
		* more details.
		*/

		#include <linux/init.h>
		#include <linux/module.h>
		#include <linux/device.h>
		#include <linux/completion.h>
		#include <linux/hyperv.h>
		#include <linux/serio.h>
		#include <linux/slab.h>

		/*
		* Current version 1.0
		*
		*/
		#define SYNTH_KBD_VERSION_MAJOR 1
		#define SYNTH_KBD_VERSION_MINOR 0
		#define SYNTH_KBD_VERSION (SYNTH_KBD_VERSION_MINOR \| \
		(SYNTH_KBD_VERSION_MAJOR << 16))


		/*
		* Message types in the synthetic input protocol
		*/
		enum synth_kbd_msg_type {
		SYNTH_KBD_PROTOCOL_REQUEST = 1,
		SYNTH_KBD_PROTOCOL_RESPONSE = 2,
		SYNTH_KBD_EVENT = 3,
		SYNTH_KBD_LED_INDICATORS = 4,
		};

		/*
		* Basic message structures.
		*/
		struct synth_kbd_msg_hdr {
		__le32 type;
		};

		struct synth_kbd_msg {
		struct synth_kbd_msg_hdr header;
		char data[]; /* Enclosed message */
		};

		union synth_kbd_version {
		__le32 version;
		};

		/*
		* Protocol messages
		*/
		struct synth_kbd_protocol_request {
		struct synth_kbd_msg_hdr header;
		union synth_kbd_version version_requested;
		};

		#define PROTOCOL_ACCEPTED BIT(0)
		struct synth_kbd_protocol_response {
		struct synth_kbd_msg_hdr header;
		__le32 proto_status;
		};

		#define IS_UNICODE BIT(0)
		#define IS_BREAK BIT(1)
		#define IS_E0 BIT(2)
		#define IS_E1 BIT(3)
		struct synth_kbd_keystroke {
		struct synth_kbd_msg_hdr header;
		__le16 make_code;
		__le16 reserved0;
		__le32 info; /* Additional information */
		};


		#define HK_MAXIMUM_MESSAGE_SIZE 256

		#define KBD_VSC_SEND_RING_BUFFER_SIZE (10 * PAGE_SIZE)
		#define KBD_VSC_RECV_RING_BUFFER_SIZE (10 * PAGE_SIZE)

		#define XTKBD_EMUL0 0xe0
		#define XTKBD_EMUL1 0xe1
		#define XTKBD_RELEASE 0x80


		/*
		* Represents a keyboard device
		*/
		struct hv_kbd_dev {
		struct hv_device *hv_dev;
		struct serio *hv_serio;
		struct synth_kbd_protocol_request protocol_req;
		struct synth_kbd_protocol_response protocol_resp;
		/* Synchronize the request/response if needed */
		struct completion wait_event;
		spinlock_t lock; /* protects 'started' field */
		bool started;
		};

		static void hv_kbd_on_receive(struct hv_device *hv_dev,
		struct synth_kbd_msg *msg, u32 msg_length)
		{
		struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev);
		struct synth_kbd_keystroke *ks_msg;
		unsigned long flags;
		u32 msg_type = __le32_to_cpu(msg->header.type);
		u32 info;
		u16 scan_code;

		switch (msg_type) {
		case SYNTH_KBD_PROTOCOL_RESPONSE:
		/*
		* Validate the information provided by the host.
		* If the host is giving us a bogus packet,
		* drop the packet (hoping the problem
		* goes away).
		*/
		if (msg_length < sizeof(struct synth_kbd_protocol_response)) {
		dev_err(&hv_dev->device,
		"Illegal protocol response packet (len: %d)\n",
		msg_length);
		break;
		}

		memcpy(&kbd_dev->protocol_resp, msg,
		sizeof(struct synth_kbd_protocol_response));
		complete(&kbd_dev->wait_event);
		break;

		case SYNTH_KBD_EVENT:
		/*
		* Validate the information provided by the host.
		* If the host is giving us a bogus packet,
		* drop the packet (hoping the problem
		* goes away).
		*/
		if (msg_length < sizeof(struct synth_kbd_keystroke)) {
		dev_err(&hv_dev->device,
		"Illegal keyboard event packet (len: %d)\n",
		msg_length);
		break;
		}

		ks_msg = (struct synth_kbd_keystroke *)msg;
		info = __le32_to_cpu(ks_msg->info);

		/*
		* Inject the information through the serio interrupt.
		*/
		spin_lock_irqsave(&kbd_dev->lock, flags);
		if (kbd_dev->started) {
		if (info & IS_E0)
		serio_interrupt(kbd_dev->hv_serio,
		XTKBD_EMUL0, 0);

		scan_code = __le16_to_cpu(ks_msg->make_code);
		if (info & IS_BREAK)
		scan_code \|= XTKBD_RELEASE;

		serio_interrupt(kbd_dev->hv_serio, scan_code, 0);
		}
		spin_unlock_irqrestore(&kbd_dev->lock, flags);
		break;

		default:
		dev_err(&hv_dev->device,
		"unhandled message type %d\n", msg_type);
		}
		}

		static void hv_kbd_handle_received_packet(struct hv_device *hv_dev,
		struct vmpacket_descriptor *desc,
		u32 bytes_recvd,
		u64 req_id)
		{
		struct synth_kbd_msg *msg;
		u32 msg_sz;

		switch (desc->type) {
		case VM_PKT_COMP:
		break;

		case VM_PKT_DATA_INBAND:
		/*
		* We have a packet that has "inband" data. The API used
		* for retrieving the packet guarantees that the complete
		* packet is read. So, minimally, we should be able to
		* parse the payload header safely (assuming that the host
		* can be trusted. Trusting the host seems to be a
		* reasonable assumption because in a virtualized
		* environment there is not whole lot you can do if you
		* don't trust the host.
		*
		* Nonetheless, let us validate if the host can be trusted
		* (in a trivial way). The interesting aspect of this
		* validation is how do you recover if we discover that the
		* host is not to be trusted? Simply dropping the packet, I
		* don't think is an appropriate recovery. In the interest
		* of failing fast, it may be better to crash the guest.
		* For now, I will just drop the packet!
		*/

		msg_sz = bytes_recvd - (desc->offset8 << 3);
		if (msg_sz <= sizeof(struct synth_kbd_msg_hdr)) {
		/*
		* Drop the packet and hope
		* the problem magically goes away.
		*/
		dev_err(&hv_dev->device,
		"Illegal packet (type: %d, tid: %llx, size: %d)\n",
		desc->type, req_id, msg_sz);
		break;
		}

		msg = (void *)desc + (desc->offset8 << 3);
		hv_kbd_on_receive(hv_dev, msg, msg_sz);
		break;

		default:
		dev_err(&hv_dev->device,
		"unhandled packet type %d, tid %llx len %d\n",
		desc->type, req_id, bytes_recvd);
		break;
		}
		}

		static void hv_kbd_on_channel_callback(void *context)
		{
		struct hv_device *hv_dev = context;
		void *buffer;
		int bufferlen = 0x100; /* Start with sensible size */
		u32 bytes_recvd;
		u64 req_id;
		int error;

		buffer = kmalloc(bufferlen, GFP_ATOMIC);
		if (!buffer)
		return;

		while (1) {
		error = vmbus_recvpacket_raw(hv_dev->channel, buffer, bufferlen,
		&bytes_recvd, &req_id);
		switch (error) {
		case 0:
		if (bytes_recvd == 0) {
		kfree(buffer);
		return;
		}

		hv_kbd_handle_received_packet(hv_dev, buffer,
		bytes_recvd, req_id);
		break;

		case -ENOBUFS:
		kfree(buffer);
		/* Handle large packet */
		bufferlen = bytes_recvd;
		buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
		if (!buffer)
		return;
		break;
		}
		}
		}

		static int hv_kbd_connect_to_vsp(struct hv_device *hv_dev)
		{
		struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev);
		struct synth_kbd_protocol_request *request;
		struct synth_kbd_protocol_response *response;
		u32 proto_status;
		int error;

		request = &kbd_dev->protocol_req;
		memset(request, 0, sizeof(struct synth_kbd_protocol_request));
		request->header.type = __cpu_to_le32(SYNTH_KBD_PROTOCOL_REQUEST);
		request->version_requested.version = __cpu_to_le32(SYNTH_KBD_VERSION);

		error = vmbus_sendpacket(hv_dev->channel, request,
		sizeof(struct synth_kbd_protocol_request),
		(unsigned long)request,
		VM_PKT_DATA_INBAND,
		VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
		if (error)
		return error;

		if (!wait_for_completion_timeout(&kbd_dev->wait_event, 10 * HZ))
		return -ETIMEDOUT;

		response = &kbd_dev->protocol_resp;
		proto_status = __le32_to_cpu(response->proto_status);
		if (!(proto_status & PROTOCOL_ACCEPTED)) {
		dev_err(&hv_dev->device,
		"synth_kbd protocol request failed (version %d)\n",
		SYNTH_KBD_VERSION);
		return -ENODEV;
		}

		return 0;
		}

		static int hv_kbd_start(struct serio *serio)
		{
		struct hv_kbd_dev *kbd_dev = serio->port_data;
		unsigned long flags;

		spin_lock_irqsave(&kbd_dev->lock, flags);
		kbd_dev->started = true;
		spin_unlock_irqrestore(&kbd_dev->lock, flags);

		return 0;
		}

		static void hv_kbd_stop(struct serio *serio)
		{
		struct hv_kbd_dev *kbd_dev = serio->port_data;
		unsigned long flags;

		spin_lock_irqsave(&kbd_dev->lock, flags);
		kbd_dev->started = false;
		spin_unlock_irqrestore(&kbd_dev->lock, flags);
		}

		static int hv_kbd_probe(struct hv_device *hv_dev,
		const struct hv_vmbus_device_id *dev_id)
		{
		struct hv_kbd_dev *kbd_dev;
		struct serio *hv_serio;
		int error;

		kbd_dev = kzalloc(sizeof(struct hv_kbd_dev), GFP_KERNEL);
		hv_serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
		if (!kbd_dev \|\| !hv_serio) {
		error = -ENOMEM;
		goto err_free_mem;
		}

		kbd_dev->hv_dev = hv_dev;
		kbd_dev->hv_serio = hv_serio;
		spin_lock_init(&kbd_dev->lock);
		init_completion(&kbd_dev->wait_event);
		hv_set_drvdata(hv_dev, kbd_dev);

		hv_serio->dev.parent = &hv_dev->device;
		hv_serio->id.type = SERIO_8042_XL;
		hv_serio->port_data = kbd_dev;
		strlcpy(hv_serio->name, dev_name(&hv_dev->device),
		sizeof(hv_serio->name));
		strlcpy(hv_serio->phys, dev_name(&hv_dev->device),
		sizeof(hv_serio->phys));

		hv_serio->start = hv_kbd_start;
		hv_serio->stop = hv_kbd_stop;

		error = vmbus_open(hv_dev->channel,
		KBD_VSC_SEND_RING_BUFFER_SIZE,
		KBD_VSC_RECV_RING_BUFFER_SIZE,
		NULL, 0,
		hv_kbd_on_channel_callback,
		hv_dev);
		if (error)
		goto err_free_mem;

		error = hv_kbd_connect_to_vsp(hv_dev);
		if (error)
		goto err_close_vmbus;

		serio_register_port(kbd_dev->hv_serio);
		return 0;

		err_close_vmbus:
		vmbus_close(hv_dev->channel);
		err_free_mem:
		kfree(hv_serio);
		kfree(kbd_dev);
		return error;
		}

		static int hv_kbd_remove(struct hv_device *hv_dev)
		{
		struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev);

		serio_unregister_port(kbd_dev->hv_serio);
		vmbus_close(hv_dev->channel);
		kfree(kbd_dev);

		hv_set_drvdata(hv_dev, NULL);

		return 0;
		}

		/*
		* Keyboard GUID
		* {f912ad6d-2b17-48ea-bd65-f927a61c7684}
		*/
		#define HV_KBD_GUID \
		.guid = { \
		0x6d, 0xad, 0x12, 0xf9, 0x17, 0x2b, 0xea, 0x48, \
		0xbd, 0x65, 0xf9, 0x27, 0xa6, 0x1c, 0x76, 0x84 \
		}

		static const struct hv_vmbus_device_id id_table[] = {
		/* Keyboard guid */
		{ HV_KBD_GUID, },
		{ },
		};

		MODULE_DEVICE_TABLE(vmbus, id_table);

		static struct hv_driver hv_kbd_drv = {
		.name = KBUILD_MODNAME,
		.id_table = id_table,
		.probe = hv_kbd_probe,
		.remove = hv_kbd_remove,
		};

		static int __init hv_kbd_init(void)
		{
		return vmbus_driver_register(&hv_kbd_drv);
		}

		static void __exit hv_kbd_exit(void)
		{
		vmbus_driver_unregister(&hv_kbd_drv);
		}

		MODULE_LICENSE("GPL");
		module_init(hv_kbd_init);
		module_exit(hv_kbd_exit);