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Date: Sun, 29 Jun 2014 14:14:33 +0800
From: Antonio Borneo <borneo.antonio@...il.com>
To: Jiri Kosina <jkosina@...e.cz>, linux-input@...r.kernel.org,
David Barksdale <dbarksdale@...ogix.com>
Cc: linux-kernel@...r.kernel.org,
Antonio Borneo <borneo.antonio@...il.com>
Subject: [PATCH] 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@...il.com>
---
drivers/hid/hid-cp2112.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 101 insertions(+), 1 deletion(-)
diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c
index 3952d90..1260a8a 100644
--- a/drivers/hid/hid-cp2112.c
+++ b/drivers/hid/hid-cp2112.c
@@ -429,6 +429,104 @@ 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)) {
+ ret = 0;
+ goto power_normal;
+ }
+
+ 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;
+ }
+
+ ret = 0;
+power_normal:
+ hid_hw_power(hdev, PM_HINT_NORMAL);
+ hid_dbg(hdev, "I2C transfer finished: %d\n", ret);
+ return (ret) ? ret : 1;
+}
+
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 +693,8 @@ power_normal:
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 +704,7 @@ 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,
};
--
2.0.1
--
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