Add an additional status check before starting a transaction. If the
check fails wait for some time to tolerate multi-master mode. After the
timeout expires trigger the recovery.
Signed-off-by: Jan Glauber <jglauber@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-octeon-core.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)
diff --git a/drivers/i2c/busses/i2c-octeon-core.c b/drivers/i2c/busses/i2c-octeon-core.c
index 5e63b17..f526511 100644
--- a/drivers/i2c/busses/i2c-octeon-core.c
+++ b/drivers/i2c/busses/i2c-octeon-core.c
@@ -630,6 +630,31 @@ static int octeon_i2c_hlc_comp_write(struct octeon_i2c *i2c, struct i2c_msg *msg
return ret;
}
+static int octeon_i2c_check_bus(struct octeon_i2c *i2c)
+{
+ u64 end = get_jiffies_64() + i2c->adap.timeout;
+ int stat, lines;
+
+ while (time_before64(get_jiffies_64(), end)) {
+ stat = octeon_i2c_stat_read(i2c);
+
+ /* get I2C line state */
+ lines = octeon_i2c_read_int(i2c) & (TWSI_INT_SCL | TWSI_INT_SDA);
+
+ if (stat == STAT_IDLE && lines == (TWSI_INT_SCL | TWSI_INT_SDA))
+ return 0;
+
+ if (stat == STAT_LOST_ARB_38 || stat == STAT_LOST_ARB_68 ||
+ stat == STAT_LOST_ARB_78 || stat == STAT_LOST_ARB_B0)
+ break;
+
+ usleep_range(I2C_OCTEON_EVENT_WAIT / 2, I2C_OCTEON_EVENT_WAIT);
+ }
+
+ /* bus check failed, try to recover */
+ return octeon_i2c_recovery(i2c);
+}
+
/**
* octeon_i2c_xfer - The driver's master_xfer function
* @adap: Pointer to the i2c_adapter structure
@@ -643,6 +668,10 @@ int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
struct octeon_i2c *i2c = i2c_get_adapdata(adap);
int i, ret = 0;
+ ret = octeon_i2c_check_bus(i2c);
+ if (ret)
+ goto out;
+
if (num == 1) {
if (msgs[0].len > 0 && msgs[0].len <= 8) {
if (msgs[0].flags & I2C_M_RD)
--
1.9.1
--
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