i2c: octeon: Add workaround for broken irqs on CN3860
CN3860 does not interrupt the CPU when the i2c status changes. If
we get a timeout, and see the status has in fact changed, we know we
have this problem, and drop back to polling.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index cb41814..aa5f01e 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -121,6 +121,8 @@
void __iomem *twsi_base;
struct device *dev;
bool hlc_enabled;
+ bool broken_irq_mode;
+ bool broken_irq_check;
void (*int_enable)(struct octeon_i2c *);
void (*int_disable)(struct octeon_i2c *);
void (*hlc_int_enable)(struct octeon_i2c *);
@@ -375,10 +377,32 @@
long time_left;
bool first = 1;
+ /*
+ * Some chip revisions don't assert the irq in the interrupt
+ * controller. So we must poll for the IFLG change.
+ */
+ if (i2c->broken_irq_mode) {
+ u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+ while (!octeon_i2c_test_iflg(i2c) &&
+ time_before64(get_jiffies_64(), end))
+ usleep_range(I2C_OCTEON_EVENT_WAIT / 2, I2C_OCTEON_EVENT_WAIT);
+
+ return octeon_i2c_test_iflg(i2c) ? 0 : -ETIMEDOUT;
+ }
+
i2c->int_enable(i2c);
time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_ready(i2c, &first),
i2c->adap.timeout);
i2c->int_disable(i2c);
+
+ if (i2c->broken_irq_check && !time_left &&
+ octeon_i2c_test_iflg(i2c)) {
+ dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+ i2c->broken_irq_mode = true;
+ return 0;
+ }
+
if (!time_left)
return -ETIMEDOUT;
@@ -492,15 +516,37 @@
bool first = 1;
int time_left;
+ /*
+ * Some cn38xx boards don't assert the irq in the interrupt
+ * controller. So we must poll for the valid bit change.
+ */
+ if (i2c->broken_irq_mode) {
+ u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+ while (!octeon_i2c_hlc_test_valid(i2c) &&
+ time_before64(get_jiffies_64(), end))
+ usleep_range(I2C_OCTEON_EVENT_WAIT / 2, I2C_OCTEON_EVENT_WAIT);
+
+ return octeon_i2c_hlc_test_valid(i2c) ? 0 : -ETIMEDOUT;
+ }
+
i2c->hlc_int_enable(i2c);
time_left = wait_event_timeout(i2c->queue,
octeon_i2c_hlc_test_ready(i2c, &first),
i2c->adap.timeout);
i2c->hlc_int_disable(i2c);
- if (!time_left) {
+ if (!time_left)
octeon_i2c_hlc_int_clear(i2c);
- return -ETIMEDOUT;
+
+ if (i2c->broken_irq_check && !time_left &&
+ octeon_i2c_hlc_test_valid(i2c)) {
+ dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+ i2c->broken_irq_mode = true;
+ return 0;
}
+
+ if (!time_left)
+ return -ETIMEDOUT;
return 0;
}
@@ -1143,6 +1189,9 @@
goto out;
}
+ if (OCTEON_IS_MODEL(OCTEON_CN38XX))
+ i2c->broken_irq_check = true;
+
result = octeon_i2c_init_lowlevel(i2c);
if (result) {
dev_err(i2c->dev, "init low level failed\n");