Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752310AbaGGXZs (ORCPT ); Mon, 7 Jul 2014 19:25:48 -0400 Received: from mail-pa0-f42.google.com ([209.85.220.42]:55721 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751307AbaGGXZq (ORCPT ); Mon, 7 Jul 2014 19:25:46 -0400 From: Antonio Borneo To: Jiri Kosina , linux-input@vger.kernel.org Cc: David Barksdale , linux-kernel@vger.kernel.org, Benjamin Tissoires , Antonio Borneo Subject: [PATCH v2] HID: cp2112: add I2C mode Date: Tue, 8 Jul 2014 07:25:39 +0800 Message-Id: <1404775539-10727-1-git-send-email-borneo.antonio@gmail.com> X-Mailer: git-send-email 2.0.1 In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Reviewed-by: Benjamin Tissoires --- ChangeLog v1->v2: - In cp2112_i2c_xfer() set variable "ret" directly with the expected return value: either an error number or the number of transferred messages. --- drivers/hid/hid-cp2112.c | 103 ++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 102 insertions(+), 1 deletion(-) diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c index 3952d90..a822db5 100644 --- a/drivers/hid/hid-cp2112.c +++ b/drivers/hid/hid-cp2112.c @@ -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 @@ 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 +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, }; -- 2.0.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/