[PATCH v7 04/15] i2c: octeon: Add flush writeq helper function

Jan Glauber
2016-04-25T14:39:08Z

From: Peter Swain <pswain@cavium.com>

Add helper function that reads back a value after writing to
make sure the write is finished and use it in octeon_i2c_write_int().

Signed-off-by: Peter Swain <pswain@cavium.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
drivers/i2c/busses/i2c-octeon.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index ad563cf..60a02b2 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -103,6 +103,12 @@ struct octeon_i2c {
struct device *dev;
};

+static void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)
+{
+ __raw_writeq(val, addr);
+ __raw_readq(addr); /* wait for write to land */
+}
+
/**
* octeon_i2c_reg_write - write an I2C core register
* @i2c: The struct octeon_i2c
@@ -173,8 +179,7 @@ static u64 octeon_i2c_read_int(struct octeon_i2c *i2c)
*/
static void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
{
- __raw_writeq(data, i2c->twsi_base + TWSI_INT);
- __raw_readq(i2c->twsi_base + TWSI_INT);
+ octeon_i2c_writeq_flush(data, i2c->twsi_base + TWSI_INT);
}

/**
--
1.9.1