i2c-hid.c 27.6 KB
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/*
 * HID over I2C protocol implementation
 *
 * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
 * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
 * Copyright (c) 2012 Red Hat, Inc
 *
 * This code is partly based on "USB HID support for Linux":
 *
 *  Copyright (c) 1999 Andreas Gal
 *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
 *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
 *  Copyright (c) 2007-2008 Oliver Neukum
 *  Copyright (c) 2006-2010 Jiri Kosina
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive for
 * more details.
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/wait.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/hid.h>
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#include <linux/mutex.h>
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#include <linux/acpi.h>
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#include <linux/of.h>
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#include <linux/i2c/i2c-hid.h>

/* flags */
#define I2C_HID_STARTED		(1 << 0)
#define I2C_HID_RESET_PENDING	(1 << 1)
#define I2C_HID_READ_PENDING	(1 << 2)

#define I2C_HID_PWR_ON		0x00
#define I2C_HID_PWR_SLEEP	0x01

/* debug option */
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static bool debug;
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module_param(debug, bool, 0444);
MODULE_PARM_DESC(debug, "print a lot of debug information");

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#define i2c_hid_dbg(ihid, fmt, arg...)					  \
do {									  \
	if (debug)							  \
		dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
} while (0)
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struct i2c_hid_desc {
	__le16 wHIDDescLength;
	__le16 bcdVersion;
	__le16 wReportDescLength;
	__le16 wReportDescRegister;
	__le16 wInputRegister;
	__le16 wMaxInputLength;
	__le16 wOutputRegister;
	__le16 wMaxOutputLength;
	__le16 wCommandRegister;
	__le16 wDataRegister;
	__le16 wVendorID;
	__le16 wProductID;
	__le16 wVersionID;
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	__le32 reserved;
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} __packed;

struct i2c_hid_cmd {
	unsigned int registerIndex;
	__u8 opcode;
	unsigned int length;
	bool wait;
};

union command {
	u8 data[0];
	struct cmd {
		__le16 reg;
		__u8 reportTypeID;
		__u8 opcode;
	} __packed c;
};

#define I2C_HID_CMD(opcode_) \
	.opcode = opcode_, .length = 4, \
	.registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)

/* fetch HID descriptor */
static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
/* fetch report descriptors */
static const struct i2c_hid_cmd hid_report_descr_cmd = {
		.registerIndex = offsetof(struct i2c_hid_desc,
			wReportDescRegister),
		.opcode = 0x00,
		.length = 2 };
/* commands */
static const struct i2c_hid_cmd hid_reset_cmd =		{ I2C_HID_CMD(0x01),
							  .wait = true };
static const struct i2c_hid_cmd hid_get_report_cmd =	{ I2C_HID_CMD(0x02) };
static const struct i2c_hid_cmd hid_set_report_cmd =	{ I2C_HID_CMD(0x03) };
static const struct i2c_hid_cmd hid_set_power_cmd =	{ I2C_HID_CMD(0x08) };
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static const struct i2c_hid_cmd hid_no_cmd =		{ .length = 0 };
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/*
 * These definitions are not used here, but are defined by the spec.
 * Keeping them here for documentation purposes.
 *
 * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
 * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
 * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
 * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
 */
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static DEFINE_MUTEX(i2c_hid_open_mut);

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/* The main device structure */
struct i2c_hid {
	struct i2c_client	*client;	/* i2c client */
	struct hid_device	*hid;	/* pointer to corresponding HID dev */
	union {
		__u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
		struct i2c_hid_desc hdesc;	/* the HID Descriptor */
	};
	__le16			wHIDDescRegister; /* location of the i2c
						   * register of the HID
						   * descriptor. */
	unsigned int		bufsize;	/* i2c buffer size */
	char			*inbuf;		/* Input buffer */
	char			*cmdbuf;	/* Command buffer */
	char			*argsbuf;	/* Command arguments buffer */

	unsigned long		flags;		/* device flags */

	wait_queue_head_t	wait;		/* For waiting the interrupt */
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	struct i2c_hid_platform_data pdata;
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};

static int __i2c_hid_command(struct i2c_client *client,
		const struct i2c_hid_cmd *command, u8 reportID,
		u8 reportType, u8 *args, int args_len,
		unsigned char *buf_recv, int data_len)
{
	struct i2c_hid *ihid = i2c_get_clientdata(client);
	union command *cmd = (union command *)ihid->cmdbuf;
	int ret;
	struct i2c_msg msg[2];
	int msg_num = 1;

	int length = command->length;
	bool wait = command->wait;
	unsigned int registerIndex = command->registerIndex;

	/* special case for hid_descr_cmd */
	if (command == &hid_descr_cmd) {
		cmd->c.reg = ihid->wHIDDescRegister;
	} else {
		cmd->data[0] = ihid->hdesc_buffer[registerIndex];
		cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
	}

	if (length > 2) {
		cmd->c.opcode = command->opcode;
		cmd->c.reportTypeID = reportID | reportType << 4;
	}

	memcpy(cmd->data + length, args, args_len);
	length += args_len;

	i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);

	msg[0].addr = client->addr;
	msg[0].flags = client->flags & I2C_M_TEN;
	msg[0].len = length;
	msg[0].buf = cmd->data;
	if (data_len > 0) {
		msg[1].addr = client->addr;
		msg[1].flags = client->flags & I2C_M_TEN;
		msg[1].flags |= I2C_M_RD;
		msg[1].len = data_len;
		msg[1].buf = buf_recv;
		msg_num = 2;
		set_bit(I2C_HID_READ_PENDING, &ihid->flags);
	}

	if (wait)
		set_bit(I2C_HID_RESET_PENDING, &ihid->flags);

	ret = i2c_transfer(client->adapter, msg, msg_num);

	if (data_len > 0)
		clear_bit(I2C_HID_READ_PENDING, &ihid->flags);

	if (ret != msg_num)
		return ret < 0 ? ret : -EIO;

	ret = 0;

	if (wait) {
		i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
		if (!wait_event_timeout(ihid->wait,
				!test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
				msecs_to_jiffies(5000)))
			ret = -ENODATA;
		i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
	}

	return ret;
}

static int i2c_hid_command(struct i2c_client *client,
		const struct i2c_hid_cmd *command,
		unsigned char *buf_recv, int data_len)
{
	return __i2c_hid_command(client, command, 0, 0, NULL, 0,
				buf_recv, data_len);
}

static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
		u8 reportID, unsigned char *buf_recv, int data_len)
{
	struct i2c_hid *ihid = i2c_get_clientdata(client);
	u8 args[3];
	int ret;
	int args_len = 0;
	u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);

	i2c_hid_dbg(ihid, "%s\n", __func__);

	if (reportID >= 0x0F) {
		args[args_len++] = reportID;
		reportID = 0x0F;
	}

	args[args_len++] = readRegister & 0xFF;
	args[args_len++] = readRegister >> 8;

	ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
		reportType, args, args_len, buf_recv, data_len);
	if (ret) {
		dev_err(&client->dev,
			"failed to retrieve report from device.\n");
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		return ret;
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	}

	return 0;
}

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/**
 * i2c_hid_set_or_send_report: forward an incoming report to the device
 * @client: the i2c_client of the device
 * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
 * @reportID: the report ID
 * @buf: the actual data to transfer, without the report ID
 * @len: size of buf
 * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
 */
static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
		u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
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{
	struct i2c_hid *ihid = i2c_get_clientdata(client);
	u8 *args = ihid->argsbuf;
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	const struct i2c_hid_cmd *hidcmd;
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	int ret;
	u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
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	u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
	u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
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	/* hidraw already checked that data_len < HID_MAX_BUFFER_SIZE */
	u16 size =	2			/* size */ +
			(reportID ? 1 : 0)	/* reportID */ +
			data_len		/* buf */;
	int args_len =	(reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
			2			/* dataRegister */ +
			size			/* args */;
	int index = 0;

	i2c_hid_dbg(ihid, "%s\n", __func__);

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	if (!use_data && maxOutputLength == 0)
		return -ENOSYS;

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	if (reportID >= 0x0F) {
		args[index++] = reportID;
		reportID = 0x0F;
	}

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	/*
	 * use the data register for feature reports or if the device does not
	 * support the output register
	 */
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	if (use_data) {
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		args[index++] = dataRegister & 0xFF;
		args[index++] = dataRegister >> 8;
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		hidcmd = &hid_set_report_cmd;
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	} else {
		args[index++] = outputRegister & 0xFF;
		args[index++] = outputRegister >> 8;
		hidcmd = &hid_no_cmd;
	}
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	args[index++] = size & 0xFF;
	args[index++] = size >> 8;

	if (reportID)
		args[index++] = reportID;

	memcpy(&args[index], buf, data_len);

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	ret = __i2c_hid_command(client, hidcmd, reportID,
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		reportType, args, args_len, NULL, 0);
	if (ret) {
		dev_err(&client->dev, "failed to set a report to device.\n");
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		return ret;
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	}

	return data_len;
}

static int i2c_hid_set_power(struct i2c_client *client, int power_state)
{
	struct i2c_hid *ihid = i2c_get_clientdata(client);
	int ret;

	i2c_hid_dbg(ihid, "%s\n", __func__);

	ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
		0, NULL, 0, NULL, 0);
	if (ret)
		dev_err(&client->dev, "failed to change power setting.\n");

	return ret;
}

static int i2c_hid_hwreset(struct i2c_client *client)
{
	struct i2c_hid *ihid = i2c_get_clientdata(client);
	int ret;

	i2c_hid_dbg(ihid, "%s\n", __func__);

	ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
	if (ret)
		return ret;

	i2c_hid_dbg(ihid, "resetting...\n");

	ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
	if (ret) {
		dev_err(&client->dev, "failed to reset device.\n");
		i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
		return ret;
	}

	return 0;
}

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static void i2c_hid_get_input(struct i2c_hid *ihid)
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{
	int ret, ret_size;
	int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);

	ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
	if (ret != size) {
		if (ret < 0)
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			return;
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		dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
			__func__, ret, size);
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		return;
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	}

	ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;

	if (!ret_size) {
		/* host or device initiated RESET completed */
		if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
			wake_up(&ihid->wait);
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		return;
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	}

	if (ret_size > size) {
		dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
			__func__, size, ret_size);
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		return;
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	}

	i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);

	if (test_bit(I2C_HID_STARTED, &ihid->flags))
		hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
				ret_size - 2, 1);

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	return;
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}

static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
{
	struct i2c_hid *ihid = dev_id;

	if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
		return IRQ_HANDLED;

	i2c_hid_get_input(ihid);

	return IRQ_HANDLED;
}

static int i2c_hid_get_report_length(struct hid_report *report)
{
	return ((report->size - 1) >> 3) + 1 +
		report->device->report_enum[report->type].numbered + 2;
}

static void i2c_hid_init_report(struct hid_report *report, u8 *buffer,
	size_t bufsize)
{
	struct hid_device *hid = report->device;
	struct i2c_client *client = hid->driver_data;
	struct i2c_hid *ihid = i2c_get_clientdata(client);
	unsigned int size, ret_size;

	size = i2c_hid_get_report_length(report);
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	if (i2c_hid_get_report(client,
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			report->type == HID_FEATURE_REPORT ? 0x03 : 0x01,
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			report->id, buffer, size))
		return;
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	i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, ihid->inbuf);

	ret_size = buffer[0] | (buffer[1] << 8);

	if (ret_size != size) {
		dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n",
			__func__, size, ret_size);
		return;
	}

	/* hid->driver_lock is held as we are in probe function,
	 * we just need to setup the input fields, so using
	 * hid_report_raw_event is safe. */
	hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1);
}

/*
 * Initialize all reports
 */
static void i2c_hid_init_reports(struct hid_device *hid)
{
	struct hid_report *report;
	struct i2c_client *client = hid->driver_data;
	struct i2c_hid *ihid = i2c_get_clientdata(client);
	u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);

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	if (!inbuf) {
		dev_err(&client->dev, "can not retrieve initial reports\n");
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		return;
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	}
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	list_for_each_entry(report,
		&hid->report_enum[HID_FEATURE_REPORT].report_list, list)
		i2c_hid_init_report(report, inbuf, ihid->bufsize);

	kfree(inbuf);
}

/*
 * Traverse the supplied list of reports and find the longest
 */
static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
		unsigned int *max)
{
	struct hid_report *report;
	unsigned int size;

	/* We should not rely on wMaxInputLength, as some devices may set it to
	 * a wrong length. */
	list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
		size = i2c_hid_get_report_length(report);
		if (*max < size)
			*max = size;
	}
}

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static void i2c_hid_free_buffers(struct i2c_hid *ihid)
{
	kfree(ihid->inbuf);
	kfree(ihid->argsbuf);
	kfree(ihid->cmdbuf);
	ihid->inbuf = NULL;
	ihid->cmdbuf = NULL;
	ihid->argsbuf = NULL;
	ihid->bufsize = 0;
}

static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
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{
	/* the worst case is computed from the set_report command with a
	 * reportID > 15 and the maximum report length */
	int args_len = sizeof(__u8) + /* optional ReportID byte */
		       sizeof(__u16) + /* data register */
		       sizeof(__u16) + /* size of the report */
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		       report_size; /* report */
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	ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
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	ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
	ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);

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	if (!ihid->inbuf || !ihid->argsbuf || !ihid->cmdbuf) {
		i2c_hid_free_buffers(ihid);
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		return -ENOMEM;
	}

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	ihid->bufsize = report_size;
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	return 0;
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}

static int i2c_hid_get_raw_report(struct hid_device *hid,
		unsigned char report_number, __u8 *buf, size_t count,
		unsigned char report_type)
{
	struct i2c_client *client = hid->driver_data;
	struct i2c_hid *ihid = i2c_get_clientdata(client);
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	size_t ret_count, ask_count;
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	int ret;

	if (report_type == HID_OUTPUT_REPORT)
		return -EINVAL;

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	/* +2 bytes to include the size of the reply in the query buffer */
	ask_count = min(count + 2, (size_t)ihid->bufsize);
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	ret = i2c_hid_get_report(client,
			report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
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			report_number, ihid->inbuf, ask_count);
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	if (ret < 0)
		return ret;

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	ret_count = ihid->inbuf[0] | (ihid->inbuf[1] << 8);
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	if (ret_count <= 2)
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		return 0;

	ret_count = min(ret_count, ask_count);

	/* The query buffer contains the size, dropping it in the reply */
	count = min(count, ret_count - 2);
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	memcpy(buf, ihid->inbuf + 2, count);

	return count;
}

static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
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		size_t count, unsigned char report_type, bool use_data)
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{
	struct i2c_client *client = hid->driver_data;
	int report_id = buf[0];
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	int ret;
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	if (report_type == HID_INPUT_REPORT)
		return -EINVAL;

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	if (report_id) {
		buf++;
		count--;
	}

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	ret = i2c_hid_set_or_send_report(client,
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				report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
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				report_id, buf, count, use_data);
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	if (report_id && ret >= 0)
		ret++; /* add report_id to the number of transfered bytes */

	return ret;
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}

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static int __i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
		size_t count, unsigned char report_type)
{
	struct i2c_client *client = hid->driver_data;
	struct i2c_hid *ihid = i2c_get_clientdata(client);
	bool data = true; /* SET_REPORT */

	if (report_type == HID_OUTPUT_REPORT)
		data = le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0;

	return i2c_hid_output_raw_report(hid, buf, count, report_type, data);
}

static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
		size_t count)
{
	return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
			false);
}

static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
			       __u8 *buf, size_t len, unsigned char rtype,
			       int reqtype)
{
	switch (reqtype) {
	case HID_REQ_GET_REPORT:
		return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
	case HID_REQ_SET_REPORT:
		if (buf[0] != reportnum)
			return -EINVAL;
		return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
	default:
		return -EIO;
	}
}

626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685
static int i2c_hid_parse(struct hid_device *hid)
{
	struct i2c_client *client = hid->driver_data;
	struct i2c_hid *ihid = i2c_get_clientdata(client);
	struct i2c_hid_desc *hdesc = &ihid->hdesc;
	unsigned int rsize;
	char *rdesc;
	int ret;
	int tries = 3;

	i2c_hid_dbg(ihid, "entering %s\n", __func__);

	rsize = le16_to_cpu(hdesc->wReportDescLength);
	if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
		dbg_hid("weird size of report descriptor (%u)\n", rsize);
		return -EINVAL;
	}

	do {
		ret = i2c_hid_hwreset(client);
		if (ret)
			msleep(1000);
	} while (tries-- > 0 && ret);

	if (ret)
		return ret;

	rdesc = kzalloc(rsize, GFP_KERNEL);

	if (!rdesc) {
		dbg_hid("couldn't allocate rdesc memory\n");
		return -ENOMEM;
	}

	i2c_hid_dbg(ihid, "asking HID report descriptor\n");

	ret = i2c_hid_command(client, &hid_report_descr_cmd, rdesc, rsize);
	if (ret) {
		hid_err(hid, "reading report descriptor failed\n");
		kfree(rdesc);
		return -EIO;
	}

	i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);

	ret = hid_parse_report(hid, rdesc, rsize);
	kfree(rdesc);
	if (ret) {
		dbg_hid("parsing report descriptor failed\n");
		return ret;
	}

	return 0;
}

static int i2c_hid_start(struct hid_device *hid)
{
	struct i2c_client *client = hid->driver_data;
	struct i2c_hid *ihid = i2c_get_clientdata(client);
	int ret;
686
	unsigned int bufsize = HID_MIN_BUFFER_SIZE;
687

688 689 690
	i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
	i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
	i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
691

692
	if (bufsize > ihid->bufsize) {
693 694
		i2c_hid_free_buffers(ihid);

695
		ret = i2c_hid_alloc_buffers(ihid, bufsize);
696

697
		if (ret)
698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720
			return ret;
	}

	if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
		i2c_hid_init_reports(hid);

	return 0;
}

static void i2c_hid_stop(struct hid_device *hid)
{
	struct i2c_client *client = hid->driver_data;
	struct i2c_hid *ihid = i2c_get_clientdata(client);

	hid->claimed = 0;

	i2c_hid_free_buffers(ihid);
}

static int i2c_hid_open(struct hid_device *hid)
{
	struct i2c_client *client = hid->driver_data;
	struct i2c_hid *ihid = i2c_get_clientdata(client);
721
	int ret = 0;
722

723
	mutex_lock(&i2c_hid_open_mut);
724 725 726 727
	if (!hid->open++) {
		ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
		if (ret) {
			hid->open--;
728
			goto done;
729 730 731
		}
		set_bit(I2C_HID_STARTED, &ihid->flags);
	}
732 733 734
done:
	mutex_unlock(&i2c_hid_open_mut);
	return ret;
735 736 737 738 739 740 741 742 743 744 745
}

static void i2c_hid_close(struct hid_device *hid)
{
	struct i2c_client *client = hid->driver_data;
	struct i2c_hid *ihid = i2c_get_clientdata(client);

	/* protecting hid->open to make sure we don't restart
	 * data acquistion due to a resumption we no longer
	 * care about
	 */
746
	mutex_lock(&i2c_hid_open_mut);
747 748 749 750 751 752
	if (!--hid->open) {
		clear_bit(I2C_HID_STARTED, &ihid->flags);

		/* Save some power */
		i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
	}
753
	mutex_unlock(&i2c_hid_open_mut);
754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781
}

static int i2c_hid_power(struct hid_device *hid, int lvl)
{
	struct i2c_client *client = hid->driver_data;
	struct i2c_hid *ihid = i2c_get_clientdata(client);
	int ret = 0;

	i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);

	switch (lvl) {
	case PM_HINT_FULLON:
		ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
		break;
	case PM_HINT_NORMAL:
		ret = i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
		break;
	}
	return ret;
}

static struct hid_ll_driver i2c_hid_ll_driver = {
	.parse = i2c_hid_parse,
	.start = i2c_hid_start,
	.stop = i2c_hid_stop,
	.open = i2c_hid_open,
	.close = i2c_hid_close,
	.power = i2c_hid_power,
782 783
	.output_report = i2c_hid_output_report,
	.raw_request = i2c_hid_raw_request,
784 785
};

786
static int i2c_hid_init_irq(struct i2c_client *client)
787 788 789 790 791 792 793 794 795 796
{
	struct i2c_hid *ihid = i2c_get_clientdata(client);
	int ret;

	dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);

	ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
			IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
			client->name, ihid);
	if (ret < 0) {
797
		dev_warn(&client->dev,
798 799
			"Could not register for %s interrupt, irq = %d,"
			" ret = %d\n",
800
			client->name, client->irq, ret);
801 802 803 804 805 806 807

		return ret;
	}

	return 0;
}

808
static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
809 810 811 812 813 814 815 816 817 818 819
{
	struct i2c_client *client = ihid->client;
	struct i2c_hid_desc *hdesc = &ihid->hdesc;
	unsigned int dsize;
	int ret;

	/* Fetch the length of HID description, retrieve the 4 first bytes:
	 * bytes 0-1 -> length
	 * bytes 2-3 -> bcdVersion (has to be 1.00) */
	ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer, 4);

820 821
	i2c_hid_dbg(ihid, "%s, ihid->hdesc_buffer: %4ph\n", __func__,
			ihid->hdesc_buffer);
822 823

	if (ret) {
824 825
		dev_err(&client->dev,
			"unable to fetch the size of HID descriptor (ret=%d)\n",
826 827 828 829 830
			ret);
		return -ENODEV;
	}

	dsize = le16_to_cpu(hdesc->wHIDDescLength);
831 832 833 834 835 836 837
	/*
	 * the size of the HID descriptor should at least contain
	 * its size and the bcdVersion (4 bytes), and should not be greater
	 * than sizeof(struct i2c_hid_desc) as we directly fill this struct
	 * through i2c_hid_command.
	 */
	if (dsize < 4 || dsize > sizeof(struct i2c_hid_desc)) {
838 839 840 841 842 843 844 845
		dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
			dsize);
		return -ENODEV;
	}

	/* check bcdVersion == 1.0 */
	if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
		dev_err(&client->dev,
846
			"unexpected HID descriptor bcdVersion (0x%04hx)\n",
847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864
			le16_to_cpu(hdesc->bcdVersion));
		return -ENODEV;
	}

	i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");

	ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
				dsize);
	if (ret) {
		dev_err(&client->dev, "hid_descr_cmd Fail\n");
		return -ENODEV;
	}

	i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);

	return 0;
}

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Mika Westerberg 已提交
865 866 867 868 869 870 871 872
#ifdef CONFIG_ACPI
static int i2c_hid_acpi_pdata(struct i2c_client *client,
		struct i2c_hid_platform_data *pdata)
{
	static u8 i2c_hid_guid[] = {
		0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
		0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
	};
873
	union acpi_object params[4];
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Mika Westerberg 已提交
874 875
	struct acpi_object_list input;
	struct acpi_device *adev;
876
	unsigned long long value;
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Mika Westerberg 已提交
877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892
	acpi_handle handle;

	handle = ACPI_HANDLE(&client->dev);
	if (!handle || acpi_bus_get_device(handle, &adev))
		return -ENODEV;

	input.count = ARRAY_SIZE(params);
	input.pointer = params;

	params[0].type = ACPI_TYPE_BUFFER;
	params[0].buffer.length = sizeof(i2c_hid_guid);
	params[0].buffer.pointer = i2c_hid_guid;
	params[1].type = ACPI_TYPE_INTEGER;
	params[1].integer.value = 1;
	params[2].type = ACPI_TYPE_INTEGER;
	params[2].integer.value = 1; /* HID function */
893 894 895
	params[3].type = ACPI_TYPE_PACKAGE;
	params[3].package.count = 0;
	params[3].package.elements = NULL;
M
Mika Westerberg 已提交
896

897 898
	if (ACPI_FAILURE(acpi_evaluate_integer(handle, "_DSM", &input,
								&value))) {
M
Mika Westerberg 已提交
899 900 901 902
		dev_err(&client->dev, "device _DSM execution failed\n");
		return -ENODEV;
	}

903
	pdata->hid_descriptor_address = value;
M
Mika Westerberg 已提交
904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921

	return 0;
}

static const struct acpi_device_id i2c_hid_acpi_match[] = {
	{"ACPI0C50", 0 },
	{"PNP0C50", 0 },
	{ },
};
MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
#else
static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
		struct i2c_hid_platform_data *pdata)
{
	return -ENODEV;
}
#endif

922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957
#ifdef CONFIG_OF
static int i2c_hid_of_probe(struct i2c_client *client,
		struct i2c_hid_platform_data *pdata)
{
	struct device *dev = &client->dev;
	u32 val;
	int ret;

	ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
	if (ret) {
		dev_err(&client->dev, "HID register address not provided\n");
		return -ENODEV;
	}
	if (val >> 16) {
		dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
			val);
		return -EINVAL;
	}
	pdata->hid_descriptor_address = val;

	return 0;
}

static const struct of_device_id i2c_hid_of_match[] = {
	{ .compatible = "hid-over-i2c" },
	{},
};
MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
#else
static inline int i2c_hid_of_probe(struct i2c_client *client,
		struct i2c_hid_platform_data *pdata)
{
	return -ENODEV;
}
#endif

958 959
static int i2c_hid_probe(struct i2c_client *client,
			 const struct i2c_device_id *dev_id)
960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978
{
	int ret;
	struct i2c_hid *ihid;
	struct hid_device *hid;
	__u16 hidRegister;
	struct i2c_hid_platform_data *platform_data = client->dev.platform_data;

	dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);

	if (!client->irq) {
		dev_err(&client->dev,
			"HID over i2c has not been provided an Int IRQ\n");
		return -EINVAL;
	}

	ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL);
	if (!ihid)
		return -ENOMEM;

979 980 981 982 983
	if (client->dev.of_node) {
		ret = i2c_hid_of_probe(client, &ihid->pdata);
		if (ret)
			goto err;
	} else if (!platform_data) {
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Mika Westerberg 已提交
984 985 986 987 988 989 990 991 992 993
		ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
		if (ret) {
			dev_err(&client->dev,
				"HID register address not provided\n");
			goto err;
		}
	} else {
		ihid->pdata = *platform_data;
	}

994 995 996 997
	i2c_set_clientdata(client, ihid);

	ihid->client = client;

M
Mika Westerberg 已提交
998
	hidRegister = ihid->pdata.hid_descriptor_address;
999 1000 1001 1002 1003 1004 1005
	ihid->wHIDDescRegister = cpu_to_le16(hidRegister);

	init_waitqueue_head(&ihid->wait);

	/* we need to allocate the command buffer without knowing the maximum
	 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
	 * real computation later. */
1006 1007 1008
	ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
	if (ret < 0)
		goto err;
1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020

	ret = i2c_hid_fetch_hid_descriptor(ihid);
	if (ret < 0)
		goto err;

	ret = i2c_hid_init_irq(client);
	if (ret < 0)
		goto err;

	hid = hid_allocate_device();
	if (IS_ERR(hid)) {
		ret = PTR_ERR(hid);
1021
		goto err_irq;
1022 1023 1024 1025 1026 1027
	}

	ihid->hid = hid;

	hid->driver_data = client;
	hid->ll_driver = &i2c_hid_ll_driver;
1028
	hid->hid_output_raw_report = __i2c_hid_output_raw_report;
1029
	hid->dev.parent = &client->dev;
1030
	ACPI_COMPANION_SET(&hid->dev, ACPI_COMPANION(&client->dev));
1031 1032 1033 1034 1035
	hid->bus = BUS_I2C;
	hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
	hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
	hid->product = le16_to_cpu(ihid->hdesc.wProductID);

1036
	snprintf(hid->name, sizeof(hid->name), "%s %04hX:%04hX",
1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050
		 client->name, hid->vendor, hid->product);

	ret = hid_add_device(hid);
	if (ret) {
		if (ret != -ENODEV)
			hid_err(client, "can't add hid device: %d\n", ret);
		goto err_mem_free;
	}

	return 0;

err_mem_free:
	hid_destroy_device(hid);

1051 1052
err_irq:
	free_irq(client->irq, ihid);
1053

1054
err:
1055
	i2c_hid_free_buffers(ihid);
1056 1057 1058 1059
	kfree(ihid);
	return ret;
}

1060
static int i2c_hid_remove(struct i2c_client *client)
1061 1062 1063 1064 1065 1066 1067 1068 1069
{
	struct i2c_hid *ihid = i2c_get_clientdata(client);
	struct hid_device *hid;

	hid = ihid->hid;
	hid_destroy_device(hid);

	free_irq(client->irq, ihid);

1070 1071 1072
	if (ihid->bufsize)
		i2c_hid_free_buffers(ihid);

1073 1074 1075 1076 1077 1078 1079 1080 1081 1082
	kfree(ihid);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int i2c_hid_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);

1083
	disable_irq(client->irq);
1084
	if (device_may_wakeup(&client->dev))
1085
		enable_irq_wake(client->irq);
1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097

	/* Save some power */
	i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);

	return 0;
}

static int i2c_hid_resume(struct device *dev)
{
	int ret;
	struct i2c_client *client = to_i2c_client(dev);

1098
	enable_irq(client->irq);
1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112
	ret = i2c_hid_hwreset(client);
	if (ret)
		return ret;

	if (device_may_wakeup(&client->dev))
		disable_irq_wake(client->irq);

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(i2c_hid_pm, i2c_hid_suspend, i2c_hid_resume);

static const struct i2c_device_id i2c_hid_id_table[] = {
B
Benjamin Tissoires 已提交
1113
	{ "hid", 0 },
1114 1115 1116 1117 1118 1119 1120 1121 1122 1123
	{ },
};
MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);


static struct i2c_driver i2c_hid_driver = {
	.driver = {
		.name	= "i2c_hid",
		.owner	= THIS_MODULE,
		.pm	= &i2c_hid_pm,
M
Mika Westerberg 已提交
1124
		.acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1125
		.of_match_table = of_match_ptr(i2c_hid_of_match),
1126 1127 1128
	},

	.probe		= i2c_hid_probe,
1129
	.remove		= i2c_hid_remove,
1130 1131 1132 1133 1134 1135 1136 1137 1138

	.id_table	= i2c_hid_id_table,
};

module_i2c_driver(i2c_hid_driver);

MODULE_DESCRIPTION("HID over I2C core driver");
MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
MODULE_LICENSE("GPL");