I2C doesn't define a timeout for bus busy, so an arbitrary value like
LOOP_TIMEOUT is not a good idea. Let's use the timeout value in struct
adapter which is meant for such cases and is user-configurable (via
IOCTL). To reduce the load, wait 10us instead of 1us which is good
enough for the slow frequencies used by I2C. Finally, use the
poll_timeout helper instead of open coding it.
Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-rcar.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index 0f73f0681a6e..ef10514f6215 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -19,6 +19,7 @@
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
+#include <linux/iopoll.h>
#include <linux/i2c.h>
#include <linux/i2c-smbus.h>
#include <linux/kernel.h>
@@ -225,18 +226,18 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv)
static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
{
- int i;
+ int ret;
+ u32 val;
- for (i = 0; i < LOOP_TIMEOUT; i++) {
- /* make sure that bus is not busy */
- if (!(rcar_i2c_read(priv, ICMCR) & FSDA))
- return 0;
- udelay(1);
+ ret = readl_poll_timeout(priv->io + ICMCR, val, !(val & FSDA), 10,
+ priv->adap.timeout);
+ if (ret) {
+ /* Waiting did not help, try to recover */
+ priv->recovery_icmcr = MDBS | OBPC | FSDA | FSCL;
+ ret = i2c_recover_bus(&priv->adap);
}
- /* Waiting did not help, try to recover */
- priv->recovery_icmcr = MDBS | OBPC | FSDA | FSCL;
- return i2c_recover_bus(&priv->adap);
+ return ret;
}
static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv)
--
2.20.1
