[PATCH 13/16] i2c-designware: i2c_dw_xfer_msg: Introduce a local "buf" pointer

Shinya Kuribayashi shinya.kuribayashi at necel.com
Mon Oct 12 22:53:11 EDT 2009


While we have "buf_len" local variable for dev->tx_buf_len, we don't
have such local variable for dev->tx_buf pointer.  While "buf_len" is
restored at first then updated when we're going to process a new i2c_msg
(in WRITE_IN_PROGRESS case), ->tx_buf is never done so.

Such inconsistency makes the code slightly hard to follow.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi at necel.com>
---

 Furthermore, even with this change, i2c_dw_xfer_msg() is still
 inconsistent with i2c_dw_read().  I don't have preference around
 here, but would like to sort out.  Any suggestions are welcome.

 drivers/i2c/busses/i2c-designware.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware.c b/drivers/i2c/busses/i2c-designware.c
index de006f0..b3152c2 100644
--- a/drivers/i2c/busses/i2c-designware.c
+++ b/drivers/i2c/busses/i2c-designware.c
@@ -363,6 +363,7 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
 	int rx_limit = dev->rx_fifo_depth - readl(dev->base + DW_IC_RXFLR);
 	u32 addr = msgs[dev->msg_write_idx].addr;
 	u32 buf_len = dev->tx_buf_len;
+	u8 *buf = dev->tx_buf;;
 
 	for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
 		/* if target address has changed, we need to
@@ -381,7 +382,7 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
 
 		if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
 			/* new i2c_msg */
-			dev->tx_buf = msgs[dev->msg_write_idx].buf;
+			buf	= msgs[dev->msg_write_idx].buf;
 			buf_len = msgs[dev->msg_write_idx].len;
 		}
 
@@ -390,12 +391,12 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
 				writel(0x100, dev->base + DW_IC_DATA_CMD);
 				rx_limit--;
 			} else
-				writel(*(dev->tx_buf++),
-						dev->base + DW_IC_DATA_CMD);
+				writel(*buf++, dev->base + DW_IC_DATA_CMD);
 			tx_limit--; buf_len--;
 		}
 
 		dev->tx_buf_len = buf_len;
+		dev->tx_buf = buf;
 
 		/* more bytes to be written? */
 		if (buf_len > 0) {
-- 
1.6.5




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