[PATCH RFC 1/2] media: platform: transfer format translations to soc_mediabus

[Robert Jarzmik]

Transfer the formats translations to soc_mediabus. Even is soc_camera
was to be deprecated, soc_mediabus will survive, and should describe all
that happens on the bus connecting the image processing unit of the SoC
and the sensor.

The translation engine provides an easy way to compute the formats
available in the v4l2 device, given any sensors format capabilities
bound with known image processing transformations.

Signed-off-by: Robert Jarzmik <robert.jarzmik@xxxxxxx>
---
 drivers/media/platform/soc_camera/soc_camera.c   |  7 +--
 drivers/media/platform/soc_camera/soc_mediabus.c | 65 ++++++++++++++++++++++++
 include/media/drv-intf/soc_mediabus.h            | 22 ++++++++
 include/media/soc_camera.h                       | 15 ------
 4 files changed, 88 insertions(+), 21 deletions(-)

diff --git a/drivers/media/platform/soc_camera/soc_camera.c b/drivers/media/platform/soc_camera/soc_camera.c
index 46c7186f7867..039524a20056 100644
--- a/drivers/media/platform/soc_camera/soc_camera.c
+++ b/drivers/media/platform/soc_camera/soc_camera.c
@@ -204,12 +204,7 @@ static void soc_camera_clock_stop(struct soc_camera_host *ici)
 const struct soc_camera_format_xlate *soc_camera_xlate_by_fourcc(
 	struct soc_camera_device *icd, unsigned int fourcc)
 {
-	unsigned int i;
-
-	for (i = 0; i < icd->num_user_formats; i++)
-		if (icd->user_formats[i].host_fmt->fourcc == fourcc)
-			return icd->user_formats + i;
-	return NULL;
+	return soc_mbus_xlate_by_fourcc(icd->user_formats, fourcc);
 }
 EXPORT_SYMBOL(soc_camera_xlate_by_fourcc);
 
diff --git a/drivers/media/platform/soc_camera/soc_mediabus.c b/drivers/media/platform/soc_camera/soc_mediabus.c
index e3e665e1c503..95c13055f50f 100644
--- a/drivers/media/platform/soc_camera/soc_mediabus.c
+++ b/drivers/media/platform/soc_camera/soc_mediabus.c
@@ -10,6 +10,7 @@
 
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/slab.h>
 
 #include <media/v4l2-device.h>
 #include <media/v4l2-mediabus.h>
@@ -512,6 +513,70 @@ unsigned int soc_mbus_config_compatible(const struct v4l2_mbus_config *cfg,
 }
 EXPORT_SYMBOL(soc_mbus_config_compatible);
 
+struct soc_camera_format_xlate *soc_mbus_build_fmts_xlate(
+	struct v4l2_device *v4l2_dev, struct v4l2_subdev *subdev,
+	int (*get_formats)(struct v4l2_device *, unsigned int,
+			   struct soc_camera_format_xlate *xlate))
+{
+	unsigned int i, fmts = 0, raw_fmts = 0;
+	int ret;
+	struct v4l2_subdev_mbus_code_enum code = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
+	struct soc_camera_format_xlate *user_formats;
+
+	while (!v4l2_subdev_call(subdev, pad, enum_mbus_code, NULL, &code)) {
+		raw_fmts++;
+		code.index++;
+	}
+
+	/*
+	 * First pass - only count formats this host-sensor
+	 * configuration can provide
+	 */
+	for (i = 0; i < raw_fmts; i++) {
+		ret = get_formats(v4l2_dev, i, NULL);
+		if (ret < 0)
+			return ERR_PTR(ret);
+		fmts += ret;
+	}
+
+	if (!fmts)
+		return ERR_PTR(-ENXIO);
+
+	user_formats = kcalloc(fmts + 1, sizeof(*user_formats), GFP_KERNEL);
+	if (!user_formats)
+		return ERR_PTR(-ENOMEM);
+
+	/* Second pass - actually fill data formats */
+	fmts = 0;
+	for (i = 0; i < raw_fmts; i++) {
+		ret = get_formats(v4l2_dev, i, user_formats + fmts);
+		if (ret < 0)
+			goto egfmt;
+		fmts += ret;
+	}
+	user_formats[fmts].code = 0;
+
+	return user_formats;
+egfmt:
+	kfree(user_formats);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL(soc_mbus_build_fmts_xlate);
+
+const struct soc_camera_format_xlate *soc_mbus_xlate_by_fourcc(
+	struct soc_camera_format_xlate *user_formats, unsigned int fourcc)
+{
+	unsigned int i;
+
+	for (i = 0; user_formats[i].code; i++)
+		if (user_formats[i].host_fmt->fourcc == fourcc)
+			return user_formats + i;
+	return NULL;
+}
+EXPORT_SYMBOL(soc_mbus_xlate_by_fourcc);
+
 static int __init soc_mbus_init(void)
 {
 	return 0;
diff --git a/include/media/drv-intf/soc_mediabus.h b/include/media/drv-intf/soc_mediabus.h
index 2ff773785fb6..08af52f6338c 100644
--- a/include/media/drv-intf/soc_mediabus.h
+++ b/include/media/drv-intf/soc_mediabus.h
@@ -95,6 +95,21 @@ struct soc_mbus_lookup {
 	struct soc_mbus_pixelfmt	fmt;
 };
 
+/**
+ * struct soc_camera_format_xlate - match between host and sensor formats
+ * @code: code of a sensor provided format
+ * @host_fmt: host format after host translation from code
+ *
+ * Host and sensor translation structure. Used in table of host and sensor
+ * formats matchings in soc_camera_device. A host can override the generic list
+ * generation by implementing get_formats(), and use it for format checks and
+ * format setup.
+ */
+struct soc_camera_format_xlate {
+	u32 code;
+	const struct soc_mbus_pixelfmt *host_fmt;
+};
+
 const struct soc_mbus_pixelfmt *soc_mbus_find_fmtdesc(
 	u32 code,
 	const struct soc_mbus_lookup *lookup,
@@ -108,5 +123,12 @@ int soc_mbus_samples_per_pixel(const struct soc_mbus_pixelfmt *mf,
 			unsigned int *numerator, unsigned int *denominator);
 unsigned int soc_mbus_config_compatible(const struct v4l2_mbus_config *cfg,
 					unsigned int flags);
+struct soc_camera_format_xlate *soc_mbus_build_fmts_xlate(
+	struct v4l2_device *v4l2_dev, struct v4l2_subdev *subdev,
+	int (*get_formats)(struct v4l2_device *, unsigned int,
+			   struct soc_camera_format_xlate *xlate));
+const struct soc_camera_format_xlate *soc_mbus_xlate_by_fourcc(
+	struct soc_camera_format_xlate *user_formats, unsigned int fourcc);
+
 
 #endif
diff --git a/include/media/soc_camera.h b/include/media/soc_camera.h
index 97aa13314bfd..db6ea91d5cb0 100644
--- a/include/media/soc_camera.h
+++ b/include/media/soc_camera.h
@@ -285,21 +285,6 @@ void soc_camera_host_unregister(struct soc_camera_host *ici);
 const struct soc_camera_format_xlate *soc_camera_xlate_by_fourcc(
 	struct soc_camera_device *icd, unsigned int fourcc);
 
-/**
- * struct soc_camera_format_xlate - match between host and sensor formats
- * @code: code of a sensor provided format
- * @host_fmt: host format after host translation from code
- *
- * Host and sensor translation structure. Used in table of host and sensor
- * formats matchings in soc_camera_device. A host can override the generic list
- * generation by implementing get_formats(), and use it for format checks and
- * format setup.
- */
-struct soc_camera_format_xlate {
-	u32 code;
-	const struct soc_mbus_pixelfmt *host_fmt;
-};
-
 #define SOCAM_SENSE_PCLK_CHANGED	(1 << 0)
 
 /**
-- 
2.1.4