[PATCH v2 1/3] media: mt9m111: add V4L2_CID_LINK_FREQ support

[Marco Felsch]

Add support to report the link frequency.

Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
---
The v1 of this small series can be found here:
https://lore.kernel.org/all/20220818144712.997477-1-m.felsch@xxxxxxxxxxxxxx/

Thanks a lot to Jacopo for the review feedback on my v1.

Changelog:

v2:
- use V4L2_CID_LINK_FREQ instead of V4L2_CID_PIXEL_RATE
---
 drivers/media/i2c/mt9m111.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/mt9m111.c b/drivers/media/i2c/mt9m111.c
index afc86efa9e3e..52be1c310455 100644
--- a/drivers/media/i2c/mt9m111.c
+++ b/drivers/media/i2c/mt9m111.c
@@ -1249,6 +1249,8 @@ static int mt9m111_probe(struct i2c_client *client)
 {
 	struct mt9m111 *mt9m111;
 	struct i2c_adapter *adapter = client->adapter;
+	static s64 extclk_rate;
+	struct v4l2_ctrl *ctrl;
 	int ret;
 
 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
@@ -1271,6 +1273,13 @@ static int mt9m111_probe(struct i2c_client *client)
 	if (IS_ERR(mt9m111->clk))
 		return PTR_ERR(mt9m111->clk);
 
+	ret = clk_prepare_enable(mt9m111->clk);
+	if (ret < 0)
+		return ret;
+
+	extclk_rate = clk_get_rate(mt9m111->clk);
+	clk_disable_unprepare(mt9m111->clk);
+
 	mt9m111->regulator = devm_regulator_get(&client->dev, "vdd");
 	if (IS_ERR(mt9m111->regulator)) {
 		dev_err(&client->dev, "regulator not found: %ld\n",
@@ -1285,7 +1294,7 @@ static int mt9m111_probe(struct i2c_client *client)
 	mt9m111->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
 				 V4L2_SUBDEV_FL_HAS_EVENTS;
 
-	v4l2_ctrl_handler_init(&mt9m111->hdl, 7);
+	v4l2_ctrl_handler_init(&mt9m111->hdl, 8);
 	v4l2_ctrl_new_std(&mt9m111->hdl, &mt9m111_ctrl_ops,
 			V4L2_CID_VFLIP, 0, 1, 1, 0);
 	v4l2_ctrl_new_std(&mt9m111->hdl, &mt9m111_ctrl_ops,
@@ -1309,6 +1318,16 @@ static int mt9m111_probe(struct i2c_client *client)
 				BIT(V4L2_COLORFX_NEGATIVE) |
 				BIT(V4L2_COLORFX_SOLARIZATION)),
 			V4L2_COLORFX_NONE);
+	/*
+	 * The extclk rate equals the link freq. if reg default values are used,
+	 * which is the case. This must be adapted as soon as we don't use the
+	 * default values anymore.
+	 */
+	ctrl = v4l2_ctrl_new_int_menu(&mt9m111->hdl, &mt9m111_ctrl_ops,
+				      V4L2_CID_LINK_FREQ, 0, 0, &extclk_rate);
+	if (ctrl)
+		ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
 	mt9m111->subdev.ctrl_handler = &mt9m111->hdl;
 	if (mt9m111->hdl.error) {
 		ret = mt9m111->hdl.error;
-- 
2.30.2