[PATCH v8 06/14] media: ov02c10: ov02c10_check_hwcfg() improvements

[Hans de Goede <hdegoede@xxxxxxxxxx>]

ov02c10_check_hwcfg() improvements:
- Drop unnecessary return -ENXIO when there is no fwnode, this is already
  caught by the fwnode_graph_get_next_endpoint() call
- Use dev_err_probe() in ov02c10_check_hwcfg()
- Make sure all error messages have '\n' at the end
- Add missing fwnode_handle_put() on clock-frequency read errors
- Check clock-frequency matches OV02C10_MCLK
- Log an error on v4l2_fwnode_endpoint_alloc_parse() failure
- ov02c10 code supports 1 or 2 lane setups not 2 or 4 lane setups
- replace return -EINVAL no mipi-lanes mismatch with
  goto check_hwcfg_error to properly free the bus_cfg
- Don't log an error in probe() when ov02c10_check_hwcfg() fails, in all
  cases ov02c10_check_hwcfg() already logs an error using dev_probe_err()
  and if the error is -EPROBE_DEFER then we don't want to keep logging that
  multiple times until the dependency is resolved (dev_probe_err()
  suppresses logging for -EPROBE_DEFER errors)

Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
 drivers/media/i2c/ov02c10.c | 55 +++++++++++++++++++++----------------
 1 file changed, 31 insertions(+), 24 deletions(-)

diff --git a/drivers/media/i2c/ov02c10.c b/drivers/media/i2c/ov02c10.c
index 4b1b41f74ca2..a6ea747243e6 100644
--- a/drivers/media/i2c/ov02c10.c
+++ b/drivers/media/i2c/ov02c10.c
@@ -921,30 +921,38 @@ static int ov02c10_check_hwcfg(struct device *dev, struct ov02c10 *ov02c10)
 	struct v4l2_fwnode_endpoint bus_cfg = {
 		.bus_type = V4L2_MBUS_CSI2_DPHY
 	};
-	struct fwnode_handle *ep;
-	struct fwnode_handle *fwnode = dev_fwnode(dev);
+	struct fwnode_handle *ep, *fwnode = dev_fwnode(dev);
 	unsigned long link_freq_bitmap;
-	u32 ext_clk;
+	u32 mclk;
 	int ret;
 
-	if (!fwnode)
-		return -ENXIO;
-
-	ep = fwnode_graph_get_next_endpoint(fwnode, NULL);
+	/*
+	 * Sometimes the fwnode graph is initialized by the bridge driver,
+	 * wait for this.
+	 */
+	ep = fwnode_graph_get_endpoint_by_id(fwnode, 0, 0, 0);
 	if (!ep)
-		return -EPROBE_DEFER;
+		return dev_err_probe(dev, -EPROBE_DEFER,
+				     "waiting for fwnode graph endpoint\n");
 
-	ret = fwnode_property_read_u32(dev_fwnode(dev), "clock-frequency",
-				       &ext_clk);
+	ret = fwnode_property_read_u32(fwnode, "clock-frequency", &mclk);
 	if (ret) {
-		dev_err(dev, "can't get clock frequency");
-		return ret;
+		fwnode_handle_put(ep);
+		return dev_err_probe(dev, ret,
+				     "reading clock-frequency property\n");
+	}
+
+	if (mclk != OV02C10_MCLK) {
+		fwnode_handle_put(ep);
+		return dev_err_probe(dev, -EINVAL,
+				     "external clock %u is not supported\n",
+				     mclk);
 	}
 
 	ret = v4l2_fwnode_endpoint_alloc_parse(ep, &bus_cfg);
 	fwnode_handle_put(ep);
 	if (ret)
-		return ret;
+		return dev_err_probe(dev, ret, "parsing endpoint failed\n");
 
 	ret = v4l2_link_freq_to_bitmap(dev, bus_cfg.link_frequencies,
 				       bus_cfg.nr_of_link_frequencies,
@@ -952,22 +960,23 @@ static int ov02c10_check_hwcfg(struct device *dev, struct ov02c10 *ov02c10)
 				       ARRAY_SIZE(link_freq_menu_items),
 				       &link_freq_bitmap);
 	if (ret)
-		goto out_err;
+		goto check_hwcfg_error;
 
 	/* v4l2_link_freq_to_bitmap() guarantees at least 1 bit is set */
 	ov02c10->link_freq_index = ffs(link_freq_bitmap) - 1;
 
-	if (bus_cfg.bus.mipi_csi2.num_data_lanes != 2 &&
-	    bus_cfg.bus.mipi_csi2.num_data_lanes != 4) {
-		dev_err(dev, "number of CSI2 data lanes %d is not supported",
-			bus_cfg.bus.mipi_csi2.num_data_lanes);
-		return(-EINVAL);
+	if (bus_cfg.bus.mipi_csi2.num_data_lanes != 1 &&
+	    bus_cfg.bus.mipi_csi2.num_data_lanes != 2) {
+		ret = dev_err_probe(dev, -EINVAL,
+				    "number of CSI2 data lanes %u is not supported\n",
+				    bus_cfg.bus.mipi_csi2.num_data_lanes);
+		goto check_hwcfg_error;
 	}
+
 	ov02c10->mipi_lanes = bus_cfg.bus.mipi_csi2.num_data_lanes;
 
-out_err:
+check_hwcfg_error:
 	v4l2_fwnode_endpoint_free(&bus_cfg);
-
 	return ret;
 }
 
@@ -994,10 +1003,8 @@ static int ov02c10_probe(struct i2c_client *client)
 
 	/* Check HW config */
 	ret = ov02c10_check_hwcfg(&client->dev, ov02c10);
-	if (ret) {
-		dev_err(&client->dev, "failed to check hwcfg: %d", ret);
+	if (ret)
 		return ret;
-	}
 
 	v4l2_i2c_subdev_init(&ov02c10->sd, client, &ov02c10_subdev_ops);
 	ov02c10_get_pm_resources(&client->dev);
-- 
2.48.1