[PATCH v3 4/4] media: ipu-bridge: Request non-continuous clock for ov5693 on IPU6

[Fernando Rimoli <fernandorimoli11@gmail.com>]

The ov5693 (INT33BE / OVTI5693) needs its MIPI clock lane gated while
idle for the IPU6 CSI-2 receiver to lock onto the link; otherwise the
sensor streams but capture times out and no frames arrive. The sensor
driver gates the clock lane when the endpoint requests a non-continuous
clock, so the bridge has to supply that property.

The same sensor works with a free-running clock on the IPU3, and other
sensors are unaffected, so add the "clock-noncontinuous" endpoint
property only for the ov5693 and only when the bridge sits on an IPU6
(matched against ipu6_pci_tbl). Non-PCI bridge instances (e.g. the IVSC
mei_csi path) are skipped.

Signed-off-by: Fernando Rimoli <fernandorimoli11@gmail.com>
---
 drivers/media/pci/intel/ipu-bridge.c | 30 ++++++++++++++++++++++++++++
 include/media/ipu-bridge.h           |  2 +-
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/media/pci/intel/ipu-bridge.c b/drivers/media/pci/intel/ipu-bridge.c
index b70d61099..98773a99a 100644
--- a/drivers/media/pci/intel/ipu-bridge.c
+++ b/drivers/media/pci/intel/ipu-bridge.c
@@ -8,6 +8,7 @@
 #include <linux/dmi.h>
 #include <linux/i2c.h>
 #include <linux/mei_cl_bus.h>
+#include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/property.h>
@@ -15,6 +16,7 @@
 #include <linux/workqueue.h>
 
 #include <media/ipu-bridge.h>
+#include <media/ipu6-pci-table.h>
 #include <media/v4l2-fwnode.h>
 
 #define ADEV_DEV(adev) ACPI_PTR(&((adev)->dev))
@@ -383,6 +385,25 @@ int ipu_bridge_parse_ssdb(struct acpi_device *adev, struct ipu_sensor *sensor)
 }
 EXPORT_SYMBOL_NS_GPL(ipu_bridge_parse_ssdb, "INTEL_IPU_BRIDGE");
 
+/*
+ * The ov5693 (INT33BE / OVTI5693, on Microsoft Surface devices) only locks
+ * onto the IPU6 CSI-2 receiver when its clock lane is gated while idle, which
+ * the sensor driver does when the endpoint requests a non-continuous clock.
+ * The same sensor works with a free-running clock on the IPU3, so only request
+ * the non-continuous clock on the IPU6 variants, keyed off the bridge's PCI ID.
+ */
+static bool ipu_bridge_needs_ncont_clock(struct ipu_bridge *bridge,
+					 const struct ipu_sensor_config *cfg)
+{
+	if (strcmp(cfg->hid, "INT33BE") && strcmp(cfg->hid, "OVTI5693"))
+		return false;
+
+	if (!dev_is_pci(bridge->dev))
+		return false;
+
+	return !!pci_match_id(ipu6_pci_tbl, to_pci_dev(bridge->dev));
+}
+
 static void ipu_bridge_create_fwnode_properties(
 	struct ipu_sensor *sensor,
 	struct ipu_bridge *bridge,
@@ -463,6 +484,15 @@ static void ipu_bridge_create_fwnode_properties(
 			cfg->link_freqs,
 			cfg->nr_link_freqs);
 
+	/*
+	 * This must stay after the link-frequencies above: the property array
+	 * is NULL-terminated, so the entry only takes effect when a preceding
+	 * slot is populated. All IPU6 ov5693 configs define a link frequency.
+	 */
+	if (ipu_bridge_needs_ncont_clock(bridge, cfg))
+		sensor->ep_properties[4] =
+			PROPERTY_ENTRY_BOOL("clock-noncontinuous");
+
 	sensor->ipu_properties[0] = PROPERTY_ENTRY_U32_ARRAY_LEN(
 					sensor->prop_names.data_lanes,
 					bridge->data_lanes, sensor->lanes);
diff --git a/include/media/ipu-bridge.h b/include/media/ipu-bridge.h
index 16fac7654..48eb1e270 100644
--- a/include/media/ipu-bridge.h
+++ b/include/media/ipu-bridge.h
@@ -141,7 +141,7 @@ struct ipu_sensor {
 	const char *vcm_type;
 
 	struct ipu_property_names prop_names;
-	struct property_entry ep_properties[5];
+	struct property_entry ep_properties[6];
 	struct property_entry dev_properties[5];
 	struct property_entry ipu_properties[3];
 	struct property_entry ivsc_properties[1];
-- 
2.43.0