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Commit b9029345 authored by Antonio Borneo's avatar Antonio Borneo Committed by Jiri Kosina
Browse files

HID: cp2112: add I2C mode 



cp2112 supports single I2C read/write transactions.  It can't combine I2C
transactions.

Add master_xfer, using similar code flow as for smbus_xfer.

Signed-off-by: default avatarAntonio Borneo <borneo.antonio@gmail.com>
Reviewed-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent beb9d007

drivers/hid/hid-cp2112.c

+102 −1
Original line number Diff line number Diff line
@@ -429,6 +429,105 @@ static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data, 
	return data_length + 4;

}



static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,

				u8 data_length)

{

	struct cp2112_write_req_report *report = buf;



	if (data_length > sizeof(report->data))

		return -EINVAL;



	report->report = CP2112_DATA_WRITE_REQUEST;

	report->slave_address = slave_address << 1;

	report->length = data_length;

	memcpy(report->data, data, data_length);

	return data_length + 3;

}



static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,

			   int num)

{

	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;

	struct hid_device *hdev = dev->hdev;

	u8 buf[64];

	ssize_t count;

	unsigned int retries;

	int ret;



	hid_dbg(hdev, "I2C %d messages\n", num);



	if (num != 1) {

		hid_err(hdev,

			"Multi-message I2C transactions not supported\n");

		return -EOPNOTSUPP;

	}



	if (msgs->flags & I2C_M_RD)

		count = cp2112_read_req(buf, msgs->addr, msgs->len);

	else

		count = cp2112_i2c_write_req(buf, msgs->addr, msgs->buf,

					     msgs->len);



	if (count < 0)

		return count;



	ret = hid_hw_power(hdev, PM_HINT_FULLON);

	if (ret < 0) {

		hid_err(hdev, "power management error: %d\n", ret);

		return ret;

	}



	ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);

	if (ret < 0) {

		hid_warn(hdev, "Error starting transaction: %d\n", ret);

		goto power_normal;

	}



	for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {

		ret = cp2112_xfer_status(dev);

		if (-EBUSY == ret)

			continue;

		if (ret < 0)

			goto power_normal;

		break;

	}



	if (XFER_STATUS_RETRIES <= retries) {

		hid_warn(hdev, "Transfer timed out, cancelling.\n");

		buf[0] = CP2112_CANCEL_TRANSFER;

		buf[1] = 0x01;



		ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);

		if (ret < 0)

			hid_warn(hdev, "Error cancelling transaction: %d\n",

				 ret);



		ret = -ETIMEDOUT;

		goto power_normal;

	}



	if (!(msgs->flags & I2C_M_RD))

		goto finish;



	ret = cp2112_read(dev, msgs->buf, msgs->len);

	if (ret < 0)

		goto power_normal;

	if (ret != msgs->len) {

		hid_warn(hdev, "short read: %d < %d\n", ret, msgs->len);

		ret = -EIO;

		goto power_normal;

	}



finish:

	/* return the number of transferred messages */

	ret = 1;



power_normal:

	hid_hw_power(hdev, PM_HINT_NORMAL);

	hid_dbg(hdev, "I2C transfer finished: %d\n", ret);

	return ret;

}



static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,

		       unsigned short flags, char read_write, u8 command,

		       int size, union i2c_smbus_data *data)
@@ -595,7 +694,8 @@ static int cp2112_xfer(struct i2c_adapter *adap, u16 addr, 


static u32 cp2112_functionality(struct i2c_adapter *adap)

{

	return I2C_FUNC_SMBUS_BYTE |

	return I2C_FUNC_I2C |

		I2C_FUNC_SMBUS_BYTE |

		I2C_FUNC_SMBUS_BYTE_DATA |

		I2C_FUNC_SMBUS_WORD_DATA |

		I2C_FUNC_SMBUS_BLOCK_DATA |
@@ -605,6 +705,7 @@ static u32 cp2112_functionality(struct i2c_adapter *adap) 
}



static const struct i2c_algorithm smbus_algorithm = {

	.master_xfer	= cp2112_i2c_xfer,

	.smbus_xfer	= cp2112_xfer,

	.functionality	= cp2112_functionality,

};