[PATCH 07/13] si2157: Briefly wait for tuning operation to complete

[Brad Love <brad@nextdimension.cc>]

Some software reports no signal found on a frequency due to immediately
checking for lock as soon as set_params returns. This waits up 40ms for
tuning operation, then from 30-150ms (dig/analog) for signal lock before
returning from set_params and set_analog_params.

Tuning typically completes in 20-30ms. Digital tuning will additionally
wait depending on signal characteristics. Analog tuning will wait the
full timeout in case of no signal.

Signed-off-by: Brad Love <brad@nextdimension.cc>
---
 drivers/media/tuners/si2157.c | 87 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)

diff --git a/drivers/media/tuners/si2157.c b/drivers/media/tuners/si2157.c
index ff462ba..1737007 100644
--- a/drivers/media/tuners/si2157.c
+++ b/drivers/media/tuners/si2157.c
@@ -318,6 +318,89 @@ static int si2157_sleep(struct dvb_frontend *fe)
 	return ret;
 }
 
+static int si2157_tune_wait(struct i2c_client *client, u8 is_digital)
+{
+#define TUN_TIMEOUT 40
+#define DIG_TIMEOUT 30
+#define ANALOG_TIMEOUT 150
+	struct si2157_dev *dev = i2c_get_clientdata(client);
+	int ret;
+	unsigned long timeout;
+	unsigned long start_time;
+	u8 wait_status;
+	u8  tune_lock_mask;
+
+	if (is_digital)
+		tune_lock_mask = 0x04;
+	else
+		tune_lock_mask = 0x02;
+
+	mutex_lock(&dev->i2c_mutex);
+
+	/* wait tuner command complete */
+	start_time = jiffies;
+	timeout = start_time + msecs_to_jiffies(TUN_TIMEOUT);
+	while (!time_after(jiffies, timeout)) {
+		ret = i2c_master_recv(client, &wait_status,
+					sizeof(wait_status));
+		if (ret < 0) {
+			goto err_mutex_unlock;
+		} else if (ret != sizeof(wait_status)) {
+			ret = -EREMOTEIO;
+			goto err_mutex_unlock;
+		}
+
+		/* tuner done? */
+		if ((wait_status & 0x81) == 0x81)
+			break;
+		usleep_range(5000, 10000);
+	}
+
+	dev_dbg(&client->dev, "tuning took %d ms, status=0x%x\n",
+		jiffies_to_msecs(jiffies) - jiffies_to_msecs(start_time),
+		wait_status);
+
+	/* if we tuned ok, wait a bit for tuner lock */
+	if ((wait_status & 0x81) == 0x81) {
+		if (is_digital)
+			timeout = jiffies + msecs_to_jiffies(DIG_TIMEOUT);
+		else
+			timeout = jiffies + msecs_to_jiffies(ANALOG_TIMEOUT);
+		while (!time_after(jiffies, timeout)) {
+			ret = i2c_master_recv(client, &wait_status,
+						sizeof(wait_status));
+			if (ret < 0) {
+				goto err_mutex_unlock;
+			} else if (ret != sizeof(wait_status)) {
+				ret = -EREMOTEIO;
+				goto err_mutex_unlock;
+			}
+
+			/* tuner locked? */
+			if (wait_status & tune_lock_mask)
+				break;
+			usleep_range(5000, 10000);
+		}
+	}
+
+	dev_dbg(&client->dev, "tuning+lock took %d ms, status=0x%x\n",
+		jiffies_to_msecs(jiffies) - jiffies_to_msecs(start_time),
+		wait_status);
+
+	if ((wait_status & 0xc0) != 0x80) {
+		ret = -ETIMEDOUT;
+		goto err_mutex_unlock;
+	}
+
+	mutex_unlock(&dev->i2c_mutex);
+	return 0;
+
+err_mutex_unlock:
+	mutex_unlock(&dev->i2c_mutex);
+	dev_dbg(&client->dev, "failed=%d\n", ret);
+	return ret;
+}
+
 static int si2157_set_params(struct dvb_frontend *fe)
 {
 	struct i2c_client *client = fe->tuner_priv;
@@ -417,6 +500,8 @@ static int si2157_set_params(struct dvb_frontend *fe)
 	dev->bandwidth = bandwidth;
 	dev->frequency = c->frequency;
 
+	si2157_tune_wait(client, 1); /* wait to complete, ignore any errors */
+
 	return 0;
 err:
 	dev->bandwidth = 0;
@@ -626,6 +711,8 @@ static int si2157_set_analog_params(struct dvb_frontend *fe,
 #endif
 	dev->bandwidth = bandwidth;
 
+	si2157_tune_wait(client, 0); /* wait to complete, ignore any errors */
+
 	return 0;
 err:
 	dev->bandwidth = 0;
-- 
2.7.4