[PATCH 1/2] drivers: ipmi: Support raw i2c packet in IPMB

[Vijay Khemka]

Many IPMB devices doesn't support smbus protocol and current driver
support only smbus devices. So added support for raw i2c packets.

Signed-off-by: Vijay Khemka <vijaykhemka at fb.com>
---
 drivers/char/ipmi/Kconfig        |  6 ++++++
 drivers/char/ipmi/ipmb_dev_int.c | 30 ++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
index a9cfe4c05e64..e5268443b478 100644
--- a/drivers/char/ipmi/Kconfig
+++ b/drivers/char/ipmi/Kconfig
@@ -139,3 +139,9 @@ config IPMB_DEVICE_INTERFACE
 	  Provides a driver for a device (Satellite MC) to
 	  receive requests and send responses back to the BMC via
 	  the IPMB interface. This module requires I2C support.
+
+config IPMB_SMBUS_DISABLE
+	bool 'Disable SMBUS protocol for sending packet to IPMB device'
+	depends on IPMB_DEVICE_INTERFACE
+	help
+	  provides functionality of sending raw i2c packets to IPMB device.
diff --git a/drivers/char/ipmi/ipmb_dev_int.c b/drivers/char/ipmi/ipmb_dev_int.c
index ae3bfba27526..2419b9a928b2 100644
--- a/drivers/char/ipmi/ipmb_dev_int.c
+++ b/drivers/char/ipmi/ipmb_dev_int.c
@@ -118,6 +118,10 @@ static ssize_t ipmb_write(struct file *file, const char __user *buf,
 	struct ipmb_dev *ipmb_dev = to_ipmb_dev(file);
 	u8 rq_sa, netf_rq_lun, msg_len;
 	union i2c_smbus_data data;
+#ifdef CONFIG_IPMB_SMBUS_DISABLE
+	unsigned char *i2c_buf;
+	struct i2c_msg i2c_msg;
+#endif
 	u8 msg[MAX_MSG_LEN];
 	ssize_t ret;
 
@@ -133,6 +137,31 @@ static ssize_t ipmb_write(struct file *file, const char __user *buf,
 	rq_sa = GET_7BIT_ADDR(msg[RQ_SA_8BIT_IDX]);
 	netf_rq_lun = msg[NETFN_LUN_IDX];
 
+#ifdef CONFIG_IPMB_SMBUS_DISABLE
+	/*
+	 * subtract 1 byte (rq_sa) from the length of the msg passed to
+	 * raw i2c_transfer
+	 */
+	msg_len = msg[IPMB_MSG_LEN_IDX] - 1;
+
+	i2c_buf = kzalloc(msg_len, GFP_KERNEL);
+	if (!i2c_buf)
+		return -EFAULT;
+
+	/* Copy message to buffer except first 2 bytes (length and address) */
+	memcpy(i2c_buf, msg+2, msg_len);
+
+	i2c_msg.addr = rq_sa;
+	i2c_msg.flags = ipmb_dev->client->flags &
+			(I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB);
+	i2c_msg.len = msg_len;
+	i2c_msg.buf = i2c_buf;
+
+	ret = i2c_transfer(ipmb_dev->client->adapter, &i2c_msg, 1);
+	kfree(i2c_buf);
+
+	return (ret == 1) ? count : ret;
+#else
 	/*
 	 * subtract rq_sa and netf_rq_lun from the length of the msg passed to
 	 * i2c_smbus_xfer
@@ -149,6 +178,7 @@ static ssize_t ipmb_write(struct file *file, const char __user *buf,
 			     I2C_SMBUS_BLOCK_DATA, &data);
 
 	return ret ? : count;
+#endif
 }
 
 static unsigned int ipmb_poll(struct file *file, poll_table *wait)
-- 
2.17.1