[PATCH] [media] ov7670: make "xclk" clock optional

[Lubomir Rintel]

When the "xclk" clock was added, it was made mandatory. This broke the
driver on an OLPC plaform which doesn't know such clock. Make it
optional.

Tested on a OLPC XO-1 laptop.

Cc: stable@xxxxxxxxxxxxxxx # 4.11+
Fixes: 0a024d634cee ("[media] ov7670: get xclk")
Signed-off-by: Lubomir Rintel <lkundrak@xxxxx>
---
 drivers/media/i2c/ov7670.c | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/media/i2c/ov7670.c b/drivers/media/i2c/ov7670.c
index 31bf577b0bd3..64d1402882c8 100644
--- a/drivers/media/i2c/ov7670.c
+++ b/drivers/media/i2c/ov7670.c
@@ -1808,17 +1808,24 @@ static int ov7670_probe(struct i2c_client *client,
 			info->pclk_hb_disable = true;
 	}
 
-	info->clk = devm_clk_get(&client->dev, "xclk");
-	if (IS_ERR(info->clk))
-		return PTR_ERR(info->clk);
-	ret = clk_prepare_enable(info->clk);
-	if (ret)
-		return ret;
+	info->clk = devm_clk_get(&client->dev, "xclk"); /* optional */
+	if (IS_ERR(info->clk)) {
+		ret = PTR_ERR(info->clk);
+		if (ret == -ENOENT)
+			info->clk = NULL;
+		else
+			return ret;
+	}
+	if (info->clk) {
+		ret = clk_prepare_enable(info->clk);
+		if (ret)
+			return ret;
 
-	info->clock_speed = clk_get_rate(info->clk) / 1000000;
-	if (info->clock_speed < 10 || info->clock_speed > 48) {
-		ret = -EINVAL;
-		goto clk_disable;
+		info->clock_speed = clk_get_rate(info->clk) / 1000000;
+		if (info->clock_speed < 10 || info->clock_speed > 48) {
+			ret = -EINVAL;
+			goto clk_disable;
+		}
 	}
 
 	ret = ov7670_init_gpio(client, info);
-- 
2.19.0