Commit 67a95c21 authored by Rishi Gupta's avatar Rishi Gupta Committed by Jiri Kosina
Browse files

HID: mcp2221: add usb to i2c-smbus host bridge 



MCP2221 is a USB HID to I2C/SMbus host bridge device. This
commit implements i2c and smbus host adapter support. 7-bit
address and i2c multi-message transaction is also supported.

Signed-off-by: default avatarRishi Gupta <gupt21@gmail.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 278de45e

MAINTAINERS

+7 −0
Original line number Diff line number Diff line
@@ -10236,6 +10236,13 @@ F: drivers/net/can/m_can/m_can.c 
F:	drivers/net/can/m_can/m_can.h

F:	drivers/net/can/m_can/m_can_platform.c









MCP2221A MICROCHIP USB-HID TO I2C BRIDGE DRIVER









M:	Rishi Gupta <gupt21@gmail.com>









L:	linux-i2c@vger.kernel.org









L:	linux-input@vger.kernel.org









S:	Maintained









F:	drivers/hid/hid-mcp2221.c

















MCP4018 AND MCP4531 MICROCHIP DIGITAL POTENTIOMETER DRIVERS









M:	Peter Rosin <peda@axentia.se>









L:	linux-iio@vger.kernel.org
































drivers/hid/Kconfig



+10
−0






























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@@ -1145,6 +1145,16 @@ config HID_ALPS







	Say Y here if you have a Alps touchpads over i2c-hid or usbhid









	and want support for its special functionalities.



















config HID_MCP2221









	tristate "Microchip MCP2221 HID USB-to-I2C/SMbus host support"









	depends on USB_HID && I2C









	---help---









	Provides I2C and SMBUS host adapter functionality over USB-HID









	through MCP2221 device.



















	To compile this driver as a module, choose M here: the module









	will be called hid-mcp2221.ko.



















endmenu



















endif # HID
































drivers/hid/Makefile



+1
−0






























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@@ -70,6 +70,7 @@ obj-$(CONFIG_HID_LOGITECH_HIDPP)	+= hid-logitech-hidpp.o







obj-$(CONFIG_HID_MACALLY)	+= hid-macally.o









obj-$(CONFIG_HID_MAGICMOUSE)	+= hid-magicmouse.o









obj-$(CONFIG_HID_MALTRON)	+= hid-maltron.o









obj-$(CONFIG_HID_MCP2221)	+= hid-mcp2221.o









obj-$(CONFIG_HID_MAYFLASH)	+= hid-mf.o









obj-$(CONFIG_HID_MICROSOFT)	+= hid-microsoft.o









obj-$(CONFIG_HID_MONTEREY)	+= hid-monterey.o
































drivers/hid/hid-ids.h



+1
−0






























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@@ -819,6 +819,7 @@







#define USB_DEVICE_ID_PICK16F1454	0x0042









#define USB_DEVICE_ID_PICK16F1454_V2	0xf2f7









#define USB_DEVICE_ID_LUXAFOR		0xf372









#define USB_DEVICE_ID_MCP2221		0x00dd



















#define USB_VENDOR_ID_MICROSOFT		0x045e









#define USB_DEVICE_ID_SIDEWINDER_GV	0x003b
































drivers/hid/hid-mcp2221.c
0 → 100644



+742
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// SPDX-License-Identifier: GPL-2.0-only









/*









 * MCP2221A - Microchip USB to I2C Host Protocol Bridge









 *









 * Copyright (c) 2020, Rishi Gupta <gupt21@gmail.com>









 *









 * Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/20005565B.pdf









 */



















#include <linux/module.h>









#include <linux/err.h>









#include <linux/mutex.h>









#include <linux/completion.h>









#include <linux/delay.h>









#include <linux/hid.h>









#include <linux/hidraw.h>









#include <linux/i2c.h>









#include "hid-ids.h"



















/* Commands codes in a raw output report */









enum {









	MCP2221_I2C_WR_DATA = 0x90,









	MCP2221_I2C_WR_NO_STOP = 0x94,









	MCP2221_I2C_RD_DATA = 0x91,









	MCP2221_I2C_RD_RPT_START = 0x93,









	MCP2221_I2C_GET_DATA = 0x40,









	MCP2221_I2C_PARAM_OR_STATUS	= 0x10,









	MCP2221_I2C_SET_SPEED = 0x20,









	MCP2221_I2C_CANCEL = 0x10,









};



















/* Response codes in a raw input report */









enum {









	MCP2221_SUCCESS = 0x00,









	MCP2221_I2C_ENG_BUSY = 0x01,









	MCP2221_I2C_START_TOUT = 0x12,









	MCP2221_I2C_STOP_TOUT = 0x62,









	MCP2221_I2C_WRADDRL_TOUT = 0x23,









	MCP2221_I2C_WRDATA_TOUT = 0x44,









	MCP2221_I2C_WRADDRL_NACK = 0x25,









	MCP2221_I2C_MASK_ADDR_NACK = 0x40,









	MCP2221_I2C_WRADDRL_SEND = 0x21,









	MCP2221_I2C_ADDR_NACK = 0x25,









	MCP2221_I2C_READ_COMPL = 0x55,









};



















/*









 * There is no way to distinguish responses. Therefore next command









 * is sent only after response to previous has been received. Mutex









 * lock is used for this purpose mainly.









 */









struct mcp2221 {









	struct hid_device *hdev;









	struct i2c_adapter adapter;









	struct mutex lock;









	struct completion wait_in_report;









	u8 *rxbuf;









	u8 txbuf[64];









	int rxbuf_idx;









	int status;









	u8 cur_i2c_clk_div;









};



















/*









 * Default i2c bus clock frequency 400 kHz. Modify this if you









 * want to set some other frequency (min 50 kHz - max 400 kHz).









 */









static uint i2c_clk_freq = 400;



















/* Synchronously send output report to the device */









static int mcp_send_report(struct mcp2221 *mcp,









					u8 *out_report, size_t len)









{









	u8 *buf;









	int ret;



















	buf = kmemdup(out_report, len, GFP_KERNEL);









	if (!buf)









		return -ENOMEM;



















	/* mcp2221 uses interrupt endpoint for out reports */









	ret = hid_hw_output_report(mcp->hdev, buf, len);









	kfree(buf);



















	if (ret < 0)









		return ret;









	return 0;









}



















/*









 * Send o/p report to the device and wait for i/p report to be









 * received from the device. If the device does not respond,









 * we timeout.









 */









static int mcp_send_data_req_status(struct mcp2221 *mcp,









			u8 *out_report, int len)









{









	int ret;









	unsigned long t;



















	reinit_completion(&mcp->wait_in_report);



















	ret = mcp_send_report(mcp, out_report, len);









	if (ret)









		return ret;



















	t = wait_for_completion_timeout(&mcp->wait_in_report,









							msecs_to_jiffies(4000));









	if (!t)









		return -ETIMEDOUT;



















	return mcp->status;









}



















/* Check pass/fail for actual communication with i2c slave */









static int mcp_chk_last_cmd_status(struct mcp2221 *mcp)









{









	memset(mcp->txbuf, 0, 8);









	mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS;



















	return mcp_send_data_req_status(mcp, mcp->txbuf, 8);









}



















/* Cancels last command releasing i2c bus just in case occupied */









static int mcp_cancel_last_cmd(struct mcp2221 *mcp)









{









	memset(mcp->txbuf, 0, 8);









	mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS;









	mcp->txbuf[2] = MCP2221_I2C_CANCEL;



















	return mcp_send_data_req_status(mcp, mcp->txbuf, 8);









}



















static int mcp_set_i2c_speed(struct mcp2221 *mcp)









{









	int ret;



















	memset(mcp->txbuf, 0, 8);









	mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS;









	mcp->txbuf[3] = MCP2221_I2C_SET_SPEED;









	mcp->txbuf[4] = mcp->cur_i2c_clk_div;



















	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 8);









	if (ret) {









		/* Small delay is needed here */









		usleep_range(980, 1000);









		mcp_cancel_last_cmd(mcp);









	}



















	return 0;









}



















/*









 * An output report can contain minimum 1 and maximum 60 user data









 * bytes. If the number of data bytes is more then 60, we send it









 * in chunks of 60 bytes. Last chunk may contain exactly 60 or less









 * bytes. Total number of bytes is informed in very first report to









 * mcp2221, from that point onwards it first collect all the data









 * from host and then send to i2c slave device.









 */









static int mcp_i2c_write(struct mcp2221 *mcp,









				struct i2c_msg *msg, int type, u8 last_status)









{









	int ret, len, idx, sent;



















	idx = 0;









	sent  = 0;









	if (msg->len < 60)









		len = msg->len;









	else









		len = 60;



















	do {









		mcp->txbuf[0] = type;









		mcp->txbuf[1] = msg->len & 0xff;









		mcp->txbuf[2] = msg->len >> 8;









		mcp->txbuf[3] = (u8)(msg->addr << 1);



















		memcpy(&mcp->txbuf[4], &msg->buf[idx], len);



















		ret = mcp_send_data_req_status(mcp, mcp->txbuf, len + 4);









		if (ret)









			return ret;



















		usleep_range(980, 1000);



















		if (last_status) {









			ret = mcp_chk_last_cmd_status(mcp);









			if (ret)









				return ret;









		}



















		sent = sent + len;









		if (sent >= msg->len)









			break;



















		idx = idx + len;









		if ((msg->len - sent) < 60)









			len = msg->len - sent;









		else









			len = 60;



















		/*









		 * Testing shows delay is needed between successive writes









		 * otherwise next write fails on first-try from i2c core.









		 * This value is obtained through automated stress testing.









		 */









		usleep_range(980, 1000);









	} while (len > 0);



















	return ret;









}



















/*









 * Device reads all data (0 - 65535 bytes) from i2c slave device and









 * stores it in device itself. This data is read back from device to









 * host in multiples of 60 bytes using input reports.









 */









static int mcp_i2c_smbus_read(struct mcp2221 *mcp,









				struct i2c_msg *msg, int type, u16 smbus_addr,









				u8 smbus_len, u8 *smbus_buf)









{









	int ret;









	u16 total_len;



















	mcp->txbuf[0] = type;









	if (msg) {









		mcp->txbuf[1] = msg->len & 0xff;









		mcp->txbuf[2] = msg->len >> 8;









		mcp->txbuf[3] = (u8)(msg->addr << 1);









		total_len = msg->len;









		mcp->rxbuf = msg->buf;









	} else {









		mcp->txbuf[1] = smbus_len;









		mcp->txbuf[2] = 0;









		mcp->txbuf[3] = (u8)(smbus_addr << 1);









		total_len = smbus_len;









		mcp->rxbuf = smbus_buf;









	}



















	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 4);









	if (ret)









		return ret;



















	mcp->rxbuf_idx = 0;



















	do {









		memset(mcp->txbuf, 0, 4);









		mcp->txbuf[0] = MCP2221_I2C_GET_DATA;



















		ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);









		if (ret)









			return ret;



















		ret = mcp_chk_last_cmd_status(mcp);









		if (ret)









			return ret;



















		usleep_range(980, 1000);









	} while (mcp->rxbuf_idx < total_len);



















	return ret;









}



















static int mcp_i2c_xfer(struct i2c_adapter *adapter,









				struct i2c_msg msgs[], int num)









{









	int ret;









	struct mcp2221 *mcp = i2c_get_adapdata(adapter);



















	hid_hw_power(mcp->hdev, PM_HINT_FULLON);



















	mutex_lock(&mcp->lock);



















	/* Setting speed before every transaction is required for mcp2221 */









	ret = mcp_set_i2c_speed(mcp);









	if (ret)









		goto exit;



















	if (num == 1) {









		if (msgs->flags & I2C_M_RD) {









			ret = mcp_i2c_smbus_read(mcp, msgs, MCP2221_I2C_RD_DATA,









							0, 0, NULL);









		} else {









			ret = mcp_i2c_write(mcp, msgs, MCP2221_I2C_WR_DATA, 1);









		}









		if (ret)









			goto exit;









		ret = num;









	} else if (num == 2) {









		/* Ex transaction; send reg address and read its contents */









		if (msgs[0].addr == msgs[1].addr &&









			!(msgs[0].flags & I2C_M_RD) &&









			 (msgs[1].flags & I2C_M_RD)) {



















			ret = mcp_i2c_write(mcp, &msgs[0],









						MCP2221_I2C_WR_NO_STOP, 0);









			if (ret)









				goto exit;



















			ret = mcp_i2c_smbus_read(mcp, &msgs[1],









						MCP2221_I2C_RD_RPT_START,









						0, 0, NULL);









			if (ret)









				goto exit;









			ret = num;









		} else {









			dev_err(&adapter->dev,









				"unsupported multi-msg i2c transaction\n");









			ret = -EOPNOTSUPP;









		}









	} else {









		dev_err(&adapter->dev,









			"unsupported multi-msg i2c transaction\n");









		ret = -EOPNOTSUPP;









	}



















exit:









	hid_hw_power(mcp->hdev, PM_HINT_NORMAL);









	mutex_unlock(&mcp->lock);









	return ret;









}



















static int mcp_smbus_write(struct mcp2221 *mcp, u16 addr,









				u8 command, u8 *buf, u8 len, int type,









				u8 last_status)









{









	int data_len, ret;



















	mcp->txbuf[0] = type;









	mcp->txbuf[1] = len + 1; /* 1 is due to command byte itself */









	mcp->txbuf[2] = 0;









	mcp->txbuf[3] = (u8)(addr << 1);









	mcp->txbuf[4] = command;



















	switch (len) {









	case 0:









		data_len = 5;









		break;









	case 1:









		mcp->txbuf[5] = buf[0];









		data_len = 6;









		break;









	case 2:









		mcp->txbuf[5] = buf[0];









		mcp->txbuf[6] = buf[1];









		data_len = 7;









		break;









	default:









		memcpy(&mcp->txbuf[5], buf, len);









		data_len = len + 5;









	}



















	ret = mcp_send_data_req_status(mcp, mcp->txbuf, data_len);









	if (ret)









		return ret;



















	if (last_status) {









		usleep_range(980, 1000);



















		ret = mcp_chk_last_cmd_status(mcp);









		if (ret)









			return ret;









	}



















	return ret;









}



















static int mcp_smbus_xfer(struct i2c_adapter *adapter, u16 addr,









				unsigned short flags, char read_write,









				u8 command, int size,









				union i2c_smbus_data *data)









{









	int ret;









	struct mcp2221 *mcp = i2c_get_adapdata(adapter);



















	hid_hw_power(mcp->hdev, PM_HINT_FULLON);



















	mutex_lock(&mcp->lock);



















	ret = mcp_set_i2c_speed(mcp);









	if (ret)









		goto exit;



















	switch (size) {



















	case I2C_SMBUS_QUICK:









		if (read_write == I2C_SMBUS_READ)









			ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA,









						addr, 0, &data->byte);









		else









			ret = mcp_smbus_write(mcp, addr, command, NULL,









						0, MCP2221_I2C_WR_DATA, 1);









		break;









	case I2C_SMBUS_BYTE:









		if (read_write == I2C_SMBUS_READ)









			ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA,









						addr, 1, &data->byte);









		else









			ret = mcp_smbus_write(mcp, addr, command, NULL,









						0, MCP2221_I2C_WR_DATA, 1);









		break;









	case I2C_SMBUS_BYTE_DATA:









		if (read_write == I2C_SMBUS_READ) {









			ret = mcp_smbus_write(mcp, addr, command, NULL,









						0, MCP2221_I2C_WR_NO_STOP, 0);









			if (ret)









				goto exit;



















			ret = mcp_i2c_smbus_read(mcp, NULL,









						MCP2221_I2C_RD_RPT_START,









						addr, 1, &data->byte);









		} else {









			ret = mcp_smbus_write(mcp, addr, command, &data->byte,









						1, MCP2221_I2C_WR_DATA, 1);









		}









		break;









	case I2C_SMBUS_WORD_DATA:









		if (read_write == I2C_SMBUS_READ) {









			ret = mcp_smbus_write(mcp, addr, command, NULL,









						0, MCP2221_I2C_WR_NO_STOP, 0);









			if (ret)









				goto exit;



















			ret = mcp_i2c_smbus_read(mcp, NULL,









						MCP2221_I2C_RD_RPT_START,









						addr, 2, (u8 *)&data->word);









		} else {









			ret = mcp_smbus_write(mcp, addr, command,









						(u8 *)&data->word, 2,









						MCP2221_I2C_WR_DATA, 1);









		}









		break;









	case I2C_SMBUS_BLOCK_DATA:









		if (read_write == I2C_SMBUS_READ) {









			ret = mcp_smbus_write(mcp, addr, command, NULL,









						0, MCP2221_I2C_WR_NO_STOP, 1);









			if (ret)









				goto exit;



















			mcp->rxbuf_idx = 0;









			mcp->rxbuf = data->block;









			mcp->txbuf[0] = MCP2221_I2C_GET_DATA;









			ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);









			if (ret)









				goto exit;









		} else {









			if (!data->block[0]) {









				ret = -EINVAL;









				goto exit;









			}









			ret = mcp_smbus_write(mcp, addr, command, data->block,









						data->block[0] + 1,









						MCP2221_I2C_WR_DATA, 1);









		}









		break;









	case I2C_SMBUS_I2C_BLOCK_DATA:









		if (read_write == I2C_SMBUS_READ) {









			ret = mcp_smbus_write(mcp, addr, command, NULL,









						0, MCP2221_I2C_WR_NO_STOP, 1);









			if (ret)









				goto exit;



















			mcp->rxbuf_idx = 0;









			mcp->rxbuf = data->block;









			mcp->txbuf[0] = MCP2221_I2C_GET_DATA;









			ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);









			if (ret)









				goto exit;









		} else {









			if (!data->block[0]) {









				ret = -EINVAL;









				goto exit;









			}









			ret = mcp_smbus_write(mcp, addr, command,









						&data->block[1], data->block[0],









						MCP2221_I2C_WR_DATA, 1);









		}









		break;









	case I2C_SMBUS_PROC_CALL:









		ret = mcp_smbus_write(mcp, addr, command,









						(u8 *)&data->word,









						2, MCP2221_I2C_WR_NO_STOP, 0);









		if (ret)









			goto exit;



















		ret = mcp_i2c_smbus_read(mcp, NULL,









						MCP2221_I2C_RD_RPT_START,









						addr, 2, (u8 *)&data->word);









		break;









	case I2C_SMBUS_BLOCK_PROC_CALL:









		ret = mcp_smbus_write(mcp, addr, command, data->block,









						data->block[0] + 1,









						MCP2221_I2C_WR_NO_STOP, 0);









		if (ret)









			goto exit;



















		ret = mcp_i2c_smbus_read(mcp, NULL,









						MCP2221_I2C_RD_RPT_START,









						addr, I2C_SMBUS_BLOCK_MAX,









						data->block);









		break;









	default:









		dev_err(&mcp->adapter.dev,









			"unsupported smbus transaction size:%d\n", size);









		ret = -EOPNOTSUPP;









	}



















exit:









	hid_hw_power(mcp->hdev, PM_HINT_NORMAL);









	mutex_unlock(&mcp->lock);









	return ret;









}



















static u32 mcp_i2c_func(struct i2c_adapter *adapter)









{









	return I2C_FUNC_I2C |









			I2C_FUNC_SMBUS_READ_BLOCK_DATA |









			I2C_FUNC_SMBUS_BLOCK_PROC_CALL |









			(I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_PEC);









}



















static const struct i2c_algorithm mcp_i2c_algo = {









	.master_xfer = mcp_i2c_xfer,









	.smbus_xfer = mcp_smbus_xfer,









	.functionality = mcp_i2c_func,









};



















/* Gives current state of i2c engine inside mcp2221 */









static int mcp_get_i2c_eng_state(struct mcp2221 *mcp,









				u8 *data, u8 idx)









{









	int ret;



















	switch (data[idx]) {









	case MCP2221_I2C_WRADDRL_NACK:









	case MCP2221_I2C_WRADDRL_SEND:









		ret = -ENXIO;









		break;









	case MCP2221_I2C_START_TOUT:









	case MCP2221_I2C_STOP_TOUT:









	case MCP2221_I2C_WRADDRL_TOUT:









	case MCP2221_I2C_WRDATA_TOUT:









		ret = -ETIMEDOUT;









		break;









	case MCP2221_I2C_ENG_BUSY:









		ret = -EAGAIN;









		break;









	case MCP2221_SUCCESS:









		ret = 0x00;









		break;









	default:









		ret = -EIO;









	}



















	return ret;









}



















/*









 * MCP2221 uses interrupt endpoint for input reports. This function









 * is called by HID layer when it receives i/p report from mcp2221,









 * which is actually a response to the previously sent command.









 *









 * MCP2221A firmware specific return codes are parsed and 0 or









 * appropriate negative error code is returned. Delayed response









 * results in timeout error and stray reponses results in -EIO.









 */









static int mcp2221_raw_event(struct hid_device *hdev,









				struct hid_report *report, u8 *data, int size)









{









	u8 *buf;









	struct mcp2221 *mcp = hid_get_drvdata(hdev);



















	switch (data[0]) {



















	case MCP2221_I2C_WR_DATA:









	case MCP2221_I2C_WR_NO_STOP:









	case MCP2221_I2C_RD_DATA:









	case MCP2221_I2C_RD_RPT_START:









		switch (data[1]) {









		case MCP2221_SUCCESS:









			mcp->status = 0;









			break;









		default:









			mcp->status = mcp_get_i2c_eng_state(mcp, data, 2);









		}









		complete(&mcp->wait_in_report);









		break;



















	case MCP2221_I2C_PARAM_OR_STATUS:









		switch (data[1]) {









		case MCP2221_SUCCESS:









			if ((mcp->txbuf[3] == MCP2221_I2C_SET_SPEED) &&









				(data[3] != MCP2221_I2C_SET_SPEED)) {









				mcp->status = -EAGAIN;









				break;









			}









			if (data[20] & MCP2221_I2C_MASK_ADDR_NACK) {









				mcp->status = -ENXIO;









				break;









			}









			mcp->status = mcp_get_i2c_eng_state(mcp, data, 8);









			break;









		default:









			mcp->status = -EIO;









		}









		complete(&mcp->wait_in_report);









		break;



















	case MCP2221_I2C_GET_DATA:









		switch (data[1]) {









		case MCP2221_SUCCESS:









			if (data[2] == MCP2221_I2C_ADDR_NACK) {









				mcp->status = -ENXIO;









				break;









			}









			if (!mcp_get_i2c_eng_state(mcp, data, 2)









				&& (data[3] == 0)) {









				mcp->status = 0;









				break;









			}









			if (data[3] == 127) {









				mcp->status = -EIO;









				break;









			}









			if (data[2] == MCP2221_I2C_READ_COMPL) {









				buf = mcp->rxbuf;









				memcpy(&buf[mcp->rxbuf_idx], &data[4], data[3]);









				mcp->rxbuf_idx = mcp->rxbuf_idx + data[3];









				mcp->status = 0;









				break;









			}









			mcp->status = -EIO;









			break;









		default:









			mcp->status = -EIO;









		}









		complete(&mcp->wait_in_report);









		break;



















	default:









		mcp->status = -EIO;









		complete(&mcp->wait_in_report);









	}



















	return 1;









}



















static int mcp2221_probe(struct hid_device *hdev,









					const struct hid_device_id *id)









{









	int ret;









	struct mcp2221 *mcp;



















	mcp = devm_kzalloc(&hdev->dev, sizeof(*mcp), GFP_KERNEL);









	if (!mcp)









		return -ENOMEM;



















	ret = hid_parse(hdev);









	if (ret) {









		hid_err(hdev, "can't parse reports\n");









		return ret;









	}



















	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);









	if (ret) {









		hid_err(hdev, "can't start hardware\n");









		return ret;









	}



















	ret = hid_hw_open(hdev);









	if (ret) {









		hid_err(hdev, "can't open device\n");









		goto err_hstop;









	}



















	mutex_init(&mcp->lock);









	init_completion(&mcp->wait_in_report);









	hid_set_drvdata(hdev, mcp);









	mcp->hdev = hdev;



















	/* Set I2C bus clock diviser */









	if (i2c_clk_freq > 400)









		i2c_clk_freq = 400;









	if (i2c_clk_freq < 50)









		i2c_clk_freq = 50;









	mcp->cur_i2c_clk_div = (12000000 / (i2c_clk_freq * 1000)) - 3;



















	mcp->adapter.owner = THIS_MODULE;









	mcp->adapter.class = I2C_CLASS_HWMON;









	mcp->adapter.algo = &mcp_i2c_algo;









	mcp->adapter.retries = 1;









	mcp->adapter.dev.parent = &hdev->dev;









	snprintf(mcp->adapter.name, sizeof(mcp->adapter.name),









			"MCP2221 usb-i2c bridge on hidraw%d",









			((struct hidraw *)hdev->hidraw)->minor);



















	ret = i2c_add_adapter(&mcp->adapter);









	if (ret) {









		hid_err(hdev, "can't add usb-i2c adapter: %d\n", ret);









		goto err_i2c;









	}









	i2c_set_adapdata(&mcp->adapter, mcp);



















	return 0;



















err_i2c:









	hid_hw_close(mcp->hdev);









err_hstop:









	hid_hw_stop(mcp->hdev);









	return ret;









}



















static void mcp2221_remove(struct hid_device *hdev)









{









	struct mcp2221 *mcp = hid_get_drvdata(hdev);



















	i2c_del_adapter(&mcp->adapter);









	hid_hw_close(mcp->hdev);









	hid_hw_stop(mcp->hdev);









}



















static const struct hid_device_id mcp2221_devices[] = {









	{ HID_USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_MCP2221) },









	{ }









};









MODULE_DEVICE_TABLE(hid, mcp2221_devices);



















static struct hid_driver mcp2221_driver = {









	.name		= "mcp2221",









	.id_table	= mcp2221_devices,









	.probe		= mcp2221_probe,









	.remove		= mcp2221_remove,









	.raw_event	= mcp2221_raw_event,









};



















/* Register with HID core */









module_hid_driver(mcp2221_driver);



















MODULE_AUTHOR("Rishi Gupta <gupt21@gmail.com>");









MODULE_DESCRIPTION("MCP2221 Microchip HID USB to I2C master bridge");









MODULE_LICENSE("GPL v2");