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OpenCloudOS-Kernel/drivers/hid/hid-mcp2221.c

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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");
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