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-rw-r--r--drivers/i2c/busses/i2c-octeon.c55
1 files changed, 46 insertions, 9 deletions
diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 4fc471ce173e..cb418140cbbe 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -109,6 +109,8 @@
#define TWSI_INT_SDA BIT_ULL(10)
#define TWSI_INT_SCL BIT_ULL(11)
+#define I2C_OCTEON_EVENT_WAIT 80 /* microseconds */
+
struct octeon_i2c {
wait_queue_head_t queue;
struct i2c_adapter adap;
@@ -339,11 +341,29 @@ static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)
return IRQ_HANDLED;
}
-static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
+static bool octeon_i2c_test_iflg(struct octeon_i2c *i2c)
{
return (octeon_i2c_ctl_read(i2c) & TWSI_CTL_IFLG);
}
+static bool octeon_i2c_test_ready(struct octeon_i2c *i2c, bool *first)
+{
+ if (octeon_i2c_test_iflg(i2c))
+ return true;
+
+ if (*first) {
+ *first = false;
+ return false;
+ }
+
+ /*
+ * IRQ has signaled an event but IFLG hasn't changed.
+ * Sleep and retry once.
+ */
+ usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
+ return octeon_i2c_test_iflg(i2c);
+}
+
/**
* octeon_i2c_wait - wait for the IFLG to be set
* @i2c: The struct octeon_i2c
@@ -353,15 +373,14 @@ static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
static int octeon_i2c_wait(struct octeon_i2c *i2c)
{
long time_left;
+ bool first = 1;
i2c->int_enable(i2c);
- time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c),
+ time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_ready(i2c, &first),
i2c->adap.timeout);
i2c->int_disable(i2c);
- if (!time_left) {
- dev_dbg(i2c->dev, "%s: timeout\n", __func__);
+ if (!time_left)
return -ETIMEDOUT;
- }
return 0;
}
@@ -427,11 +446,28 @@ static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read)
}
}
-static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c)
+static bool octeon_i2c_hlc_test_valid(struct octeon_i2c *i2c)
+{
+ return (__raw_readq(i2c->twsi_base + SW_TWSI) & SW_TWSI_V) == 0;
+}
+
+static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c, bool *first)
{
- u64 val = __raw_readq(i2c->twsi_base + SW_TWSI);
+ /* check if valid bit is cleared */
+ if (octeon_i2c_hlc_test_valid(i2c))
+ return true;
- return (val & SW_TWSI_V) == 0;
+ if (*first) {
+ *first = false;
+ return false;
+ }
+
+ /*
+ * IRQ has signaled an event but valid bit isn't cleared.
+ * Sleep and retry once.
+ */
+ usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
+ return octeon_i2c_hlc_test_valid(i2c);
}
static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c)
@@ -453,11 +489,12 @@ static void octeon_i2c_hlc_int_clear(struct octeon_i2c *i2c)
*/
static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
{
+ bool first = 1;
int time_left;
i2c->hlc_int_enable(i2c);
time_left = wait_event_timeout(i2c->queue,
- octeon_i2c_hlc_test_ready(i2c),
+ octeon_i2c_hlc_test_ready(i2c, &first),
i2c->adap.timeout);
i2c->hlc_int_disable(i2c);
if (!time_left) {