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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: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Antonio Borneo 2014-07-08 07:25:39 +08:00 committed by Jiri Kosina
parent beb9d007a8
commit b9029345ed
1 changed files with 102 additions and 1 deletions
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103
drivers/hid/hid-cp2112.c
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@ -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,
};