linux-kernel - [PATCH 1/7] media: i2c: st-mipid02: add usage of v4l2_get_link

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Message-ID: <20231125182057.1379357-2-alain.volmat@foss.st.com>
Date:   Sat, 25 Nov 2023 19:20:49 +0100
From:   Alain Volmat <alain.volmat@...s.st.com>
To:     Mauro Carvalho Chehab <mchehab@...nel.org>,
        Benjamin Mugnier <benjamin.mugnier@...s.st.com>,
        Sylvain Petinot <sylvain.petinot@...s.st.com>
CC:     Sakari Ailus <sakari.ailus@...ux.intel.com>,
        Alain Volmat <alain.volmat@...s.st.com>,
        <linux-media@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: [PATCH 1/7] media: i2c: st-mipid02: add usage of v4l2_get_link_freq

Use the helper v4l2_get_link_freq instead of performing manually
check of the LINK_FREQ or PIXELRATE ctrls.

Signed-off-by: Alain Volmat <alain.volmat@...s.st.com>
---
 drivers/media/i2c/st-mipid02.c | 66 ++++++++++------------------------
 1 file changed, 18 insertions(+), 48 deletions(-)

diff --git a/drivers/media/i2c/st-mipid02.c b/drivers/media/i2c/st-mipid02.c
index 914f915749a8..b699f0b4efe7 100644
--- a/drivers/media/i2c/st-mipid02.c
+++ b/drivers/media/i2c/st-mipid02.c
@@ -367,64 +367,34 @@ static int mipid02_detect(struct mipid02_dev *bridge)
 	return mipid02_read_reg(bridge, MIPID02_CLK_LANE_WR_REG1, &reg);
 }
 
-static u32 mipid02_get_link_freq_from_cid_link_freq(struct mipid02_dev *bridge,
-						    struct v4l2_subdev *subdev)
-{
-	struct v4l2_querymenu qm = {.id = V4L2_CID_LINK_FREQ, };
-	struct v4l2_ctrl *ctrl;
-	int ret;
-
-	ctrl = v4l2_ctrl_find(subdev->ctrl_handler, V4L2_CID_LINK_FREQ);
-	if (!ctrl)
-		return 0;
-	qm.index = v4l2_ctrl_g_ctrl(ctrl);
-
-	ret = v4l2_querymenu(subdev->ctrl_handler, &qm);
-	if (ret)
-		return 0;
-
-	return qm.value;
-}
-
-static u32 mipid02_get_link_freq_from_cid_pixel_rate(struct mipid02_dev *bridge,
-						     struct v4l2_subdev *subdev)
-{
-	struct v4l2_fwnode_endpoint *ep = &bridge->rx;
-	struct v4l2_ctrl *ctrl;
-	u32 pixel_clock;
-	u32 bpp = bpp_from_code(bridge->fmt.code);
-
-	ctrl = v4l2_ctrl_find(subdev->ctrl_handler, V4L2_CID_PIXEL_RATE);
-	if (!ctrl)
-		return 0;
-	pixel_clock = v4l2_ctrl_g_ctrl_int64(ctrl);
-
-	return pixel_clock * bpp / (2 * ep->bus.mipi_csi2.num_data_lanes);
-}
-
 /*
  * We need to know link frequency to setup clk_lane_reg1 timings. Link frequency
- * will be computed using connected device V4L2_CID_PIXEL_RATE, bit per pixel
+ * will be retrieve from connected device via v4l2_get_link_freq, bit per pixel
  * and number of lanes.
  */
 static int mipid02_configure_from_rx_speed(struct mipid02_dev *bridge)
 {
 	struct i2c_client *client = bridge->i2c_client;
 	struct v4l2_subdev *subdev = bridge->s_subdev;
-	u32 link_freq;
-
-	link_freq = mipid02_get_link_freq_from_cid_link_freq(bridge, subdev);
-	if (!link_freq) {
-		link_freq = mipid02_get_link_freq_from_cid_pixel_rate(bridge,
-								      subdev);
-		if (!link_freq) {
-			dev_err(&client->dev, "Failed to get link frequency");
-			return -EINVAL;
-		}
+	struct v4l2_fwnode_endpoint *ep = &bridge->rx;
+	u32 bpp = bpp_from_code(bridge->fmt.code);
+	/*
+	 * clk_lane_reg1 requires 4 times the unit interval time, and bitrate
+	 * is twice the link frequency, hence ui_4 = 1000000000 * 4 / 2
+	 */
+	u64 ui_4 = 2000000000;
+	s64 link_freq;
+
+	link_freq = v4l2_get_link_freq(subdev->ctrl_handler, bpp,
+				       2 * ep->bus.mipi_csi2.num_data_lanes);
+	if (link_freq < 0) {
+		dev_err(&client->dev, "Failed to get link frequency");
+		return -EINVAL;
 	}
 
-	dev_dbg(&client->dev, "detect link_freq = %d Hz", link_freq);
-	bridge->r.clk_lane_reg1 |= (2000000000 / link_freq) << 2;
+	dev_dbg(&client->dev, "detect link_freq = %lld Hz", link_freq);
+	do_div(ui_4, link_freq);
+	bridge->r.clk_lane_reg1 |= ui_4 << 2;
 
 	return 0;
 }
-- 
2.25.1