media: atmel: atmel-isc: move to staging

The Atmel ISC driver is not compliant with media controller specification.
In order to evolve this driver, it has to move to media controller, to
support enhanced features and future products which embed it.
The move to media controller involves several changes which are
not backwards compatible with the current usability of the driver.

The best example is the way the format is propagated from the top video
driver /dev/videoX down to the sensor.

In a simple configuration sensor ==> isc , the isc just calls subdev s_fmt
and controls the sensor directly. This is achieved by having a lot of code
inside the driver that will query the subdev at probe time and make a list
of formats which are usable.
Basically the user has nothing to configure, as the isc will handle
everything at the top level. This is an easy way to capture, but also comes
with the drawback of lack of flexibility.
In a more complicated pipeline
sensor ==> controller 1 ==> controller 2 ==> isc
this will not be achievable, as controller 1 and controller 2 might be
media-controller configurable, and will not propagate the formats down to
the sensor.

After discussions with the media maintainers, the decision is to move
Atmel ISC to staging as-is, to keep the Kconfig symbols and the users
to the driver in staging. Thus, all the existing users of the non
media-controller paradigm will continue to be happy and use the old config
way.

The new driver was added in the media subsystem with a different
symbol, with the conversion to media controller done, and new users
of the driver will be able to use all the new features.

This patch is merely a file move to staging, not affecting any of the
users.

The exported symbols had to be renamed to atmel_* to avoid duplication with
the new Microchip ISC driver.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

MAINTAINERS

@@ -13503,8 +13503,8 @@ L:	linux-media@vger.kernel.org
 S:	Supported
 F:	Documentation/devicetree/bindings/media/atmel,isc.yaml
 F:	Documentation/devicetree/bindings/media/microchip,xisc.yaml
-F:	drivers/media/platform/atmel/atmel-isc*
-F:	drivers/media/platform/atmel/atmel-sama*-isc*
+F:	drivers/staging/media/deprecated/atmel/atmel-isc*
+F:	drivers/staging/media/deprecated/atmel/atmel-sama*-isc*
 F:	drivers/media/platform/microchip/microchip-isc*
 F:	drivers/media/platform/microchip/microchip-sama*-isc*
 F:	include/linux/atmel-isc-media.h

drivers/media/platform/atmel/Kconfig

@@ -2,42 +2,6 @@
 
 comment "Atmel media platform drivers"
 
-config VIDEO_ATMEL_ISC
-	tristate "ATMEL Image Sensor Controller (ISC) support"
-	depends on V4L_PLATFORM_DRIVERS
-	depends on VIDEO_DEV && COMMON_CLK
-	depends on ARCH_AT91 || COMPILE_TEST
-	select MEDIA_CONTROLLER
-	select VIDEO_V4L2_SUBDEV_API
-	select VIDEOBUF2_DMA_CONTIG
-	select REGMAP_MMIO
-	select V4L2_FWNODE
-	select VIDEO_ATMEL_ISC_BASE
-	help
-	   This module makes the ATMEL Image Sensor Controller available
-	   as a v4l2 device.
-
-config VIDEO_ATMEL_XISC
-	tristate "ATMEL eXtended Image Sensor Controller (XISC) support"
-	depends on V4L_PLATFORM_DRIVERS
-	depends on VIDEO_DEV && COMMON_CLK
-	depends on ARCH_AT91 || COMPILE_TEST
-	select VIDEOBUF2_DMA_CONTIG
-	select REGMAP_MMIO
-	select V4L2_FWNODE
-	select VIDEO_ATMEL_ISC_BASE
-	select MEDIA_CONTROLLER
-	select VIDEO_V4L2_SUBDEV_API
-	help
-	   This module makes the ATMEL eXtended Image Sensor Controller
-	   available as a v4l2 device.
-
-config VIDEO_ATMEL_ISC_BASE
-	tristate
-	default n
-	help
-	  ATMEL ISC and XISC common code base.
-
 config VIDEO_ATMEL_ISI
 	tristate "ATMEL Image Sensor Interface (ISI) support"
 	depends on V4L_PLATFORM_DRIVERS

drivers/media/platform/atmel/Makefile

@@ -1,9 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0-only
-atmel-isc-objs = atmel-sama5d2-isc.o
-atmel-xisc-objs = atmel-sama7g5-isc.o
-atmel-isc-common-objs = atmel-isc-base.o atmel-isc-clk.o
 
 obj-$(CONFIG_VIDEO_ATMEL_ISI) += atmel-isi.o
-obj-$(CONFIG_VIDEO_ATMEL_ISC_BASE) += atmel-isc-common.o
-obj-$(CONFIG_VIDEO_ATMEL_ISC) += atmel-isc.o
-obj-$(CONFIG_VIDEO_ATMEL_XISC) += atmel-xisc.o

drivers/staging/media/Kconfig

@@ -51,6 +51,7 @@ menuconfig STAGING_MEDIA_DEPRECATED
 	  If in doubt, say N here.
 
 if STAGING_MEDIA_DEPRECATED
+source "drivers/staging/media/deprecated/atmel/Kconfig"
 source "drivers/staging/media/deprecated/cpia2/Kconfig"
 source "drivers/staging/media/deprecated/fsl-viu/Kconfig"
 source "drivers/staging/media/deprecated/meye/Kconfig"

drivers/staging/media/Makefile

@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_VIDEO_ATMEL_ISC_BASE)	+= deprecated/atmel/
 obj-$(CONFIG_INTEL_ATOMISP)     += atomisp/
 obj-$(CONFIG_VIDEO_CPIA2)	+= deprecated/cpia2/
 obj-$(CONFIG_VIDEO_IMX_MEDIA)	+= imx/

drivers/staging/media/deprecated/atmel/Kconfig

@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+comment "Atmel media platform drivers"
+
+config VIDEO_ATMEL_ISC
+	tristate "ATMEL Image Sensor Controller (ISC) support (DEPRECATED)"
+	depends on V4L_PLATFORM_DRIVERS
+	depends on VIDEO_DEV && COMMON_CLK
+	depends on ARCH_AT91 || COMPILE_TEST
+	depends on !VIDEO_MICROCHIP_ISC_BASE || COMPILE_TEST
+	select MEDIA_CONTROLLER
+	select VIDEO_V4L2_SUBDEV_API
+	select VIDEOBUF2_DMA_CONTIG
+	select REGMAP_MMIO
+	select V4L2_FWNODE
+	select VIDEO_ATMEL_ISC_BASE
+	help
+	   This module makes the ATMEL Image Sensor Controller available
+	   as a v4l2 device.
+
+	   This driver is deprecated and is scheduled for removal by
+	   the beginning of 2026. See the TODO file for more information.
+
+config VIDEO_ATMEL_XISC
+	tristate "ATMEL eXtended Image Sensor Controller (XISC) support (DEPRECATED)"
+	depends on V4L_PLATFORM_DRIVERS
+	depends on VIDEO_DEV && COMMON_CLK
+	depends on ARCH_AT91 || COMPILE_TEST
+	depends on !VIDEO_MICROCHIP_ISC_BASE || COMPILE_TEST
+	select VIDEOBUF2_DMA_CONTIG
+	select REGMAP_MMIO
+	select V4L2_FWNODE
+	select VIDEO_ATMEL_ISC_BASE
+	select MEDIA_CONTROLLER
+	select VIDEO_V4L2_SUBDEV_API
+	help
+	   This module makes the ATMEL eXtended Image Sensor Controller
+	   available as a v4l2 device.
+
+	   This driver is deprecated and is scheduled for removal by
+	   the beginning of 2026. See the TODO file for more information.
+
+config VIDEO_ATMEL_ISC_BASE
+	tristate
+	default n
+	help
+	  ATMEL ISC and XISC common code base.

drivers/staging/media/deprecated/atmel/Makefile

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+atmel-isc-objs = atmel-sama5d2-isc.o
+atmel-xisc-objs = atmel-sama7g5-isc.o
+atmel-isc-common-objs = atmel-isc-base.o atmel-isc-clk.o
+
+obj-$(CONFIG_VIDEO_ATMEL_ISC_BASE) += atmel-isc-common.o
+obj-$(CONFIG_VIDEO_ATMEL_ISC) += atmel-isc.o
+obj-$(CONFIG_VIDEO_ATMEL_XISC) += atmel-xisc.o

drivers/staging/media/deprecated/atmel/TODO

@@ -0,0 +1,34 @@
+The Atmel ISC driver is not compliant with media controller specification.
+In order to evolve this driver, it has to move to media controller, to
+support enhanced features and future products which embed it.
+The move to media controller involves several changes which are
+not backwards compatible with the current usability of the driver.
+
+The best example is the way the format is propagated from the top video
+driver /dev/videoX down to the sensor.
+
+In a simple configuration sensor ==> isc , the isc just calls subdev s_fmt
+and controls the sensor directly. This is achieved by having a lot of code
+inside the driver that will query the subdev at probe time and make a list
+of formats which are usable.
+Basically the user has nothing to configure, as the isc will handle
+everything at the top level. This is an easy way to capture, but also comes
+with the drawback of lack of flexibility.
+In a more complicated pipeline
+sensor ==> controller 1 ==> controller 2 ==> isc
+this will not be achievable, as controller 1 and controller 2 might be
+media-controller configurable, and will not propagate the formats down to
+the sensor.
+
+After discussions with the media maintainers, the decision is to move
+Atmel ISC to staging as-is, to keep the Kconfig symbols and the users
+to the driver in staging. Thus, all the existing users of the non
+media-controller paradigm will continue to be happy and use the old config
+way.
+
+The new driver was added in the media subsystem with a different
+symbol, with the conversion to media controller done, and new users
+of the driver will be able to use all the new features.
+
+The replacement driver is named VIDEO_MICROCHIP_ISC or
+VIDEO_MICROCHIP_XISC depending on the product flavor.

drivers/media/platform/atmel/atmel-isc-base.c → drivers/staging/media/deprecated/atmel/atmel-isc-base.c

@@ -1221,7 +1221,7 @@ static const struct v4l2_file_operations isc_fops = {
 	.poll		= vb2_fop_poll,
 };
 
-irqreturn_t isc_interrupt(int irq, void *dev_id)
+irqreturn_t atmel_isc_interrupt(int irq, void *dev_id)
 {
 	struct isc_device *isc = (struct isc_device *)dev_id;
 	struct regmap *regmap = isc->regmap;
@@ -1267,7 +1267,7 @@ irqreturn_t isc_interrupt(int irq, void *dev_id)
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(isc_interrupt);
+EXPORT_SYMBOL_GPL(atmel_isc_interrupt);
 
 static void isc_hist_count(struct isc_device *isc, u32 *min, u32 *max)
 {
@@ -1934,14 +1934,14 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier)
 	return ret;
 }
 
-const struct v4l2_async_notifier_operations isc_async_ops = {
+const struct v4l2_async_notifier_operations atmel_isc_async_ops = {
 	.bound = isc_async_bound,
 	.unbind = isc_async_unbind,
 	.complete = isc_async_complete,
 };
-EXPORT_SYMBOL_GPL(isc_async_ops);
+EXPORT_SYMBOL_GPL(atmel_isc_async_ops);
 
-void isc_subdev_cleanup(struct isc_device *isc)
+void atmel_isc_subdev_cleanup(struct isc_device *isc)
 {
 	struct isc_subdev_entity *subdev_entity;
 
@@ -1952,9 +1952,9 @@ void isc_subdev_cleanup(struct isc_device *isc)
 
 	INIT_LIST_HEAD(&isc->subdev_entities);
 }
-EXPORT_SYMBOL_GPL(isc_subdev_cleanup);
+EXPORT_SYMBOL_GPL(atmel_isc_subdev_cleanup);
 
-int isc_pipeline_init(struct isc_device *isc)
+int atmel_isc_pipeline_init(struct isc_device *isc)
 {
 	struct device *dev = isc->dev;
 	struct regmap *regmap = isc->regmap;
@@ -1993,17 +1993,17 @@ int isc_pipeline_init(struct isc_device *isc)
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(isc_pipeline_init);
+EXPORT_SYMBOL_GPL(atmel_isc_pipeline_init);
 
 /* regmap configuration */
 #define ATMEL_ISC_REG_MAX    0xd5c
-const struct regmap_config isc_regmap_config = {
+const struct regmap_config atmel_isc_regmap_config = {
 	.reg_bits       = 32,
 	.reg_stride     = 4,
 	.val_bits       = 32,
 	.max_register	= ATMEL_ISC_REG_MAX,
 };
-EXPORT_SYMBOL_GPL(isc_regmap_config);
+EXPORT_SYMBOL_GPL(atmel_isc_regmap_config);
 
 MODULE_AUTHOR("Songjun Wu");
 MODULE_AUTHOR("Eugen Hristev");

drivers/media/platform/atmel/atmel-isc-clk.c → drivers/staging/media/deprecated/atmel/atmel-isc-clk.c

@@ -277,7 +277,7 @@ static int isc_clk_register(struct isc_device *isc, unsigned int id)
 	return 0;
 }
 
-int isc_clk_init(struct isc_device *isc)
+int atmel_isc_clk_init(struct isc_device *isc)
 {
 	unsigned int i;
 	int ret;
@@ -293,9 +293,9 @@ int isc_clk_init(struct isc_device *isc)
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(isc_clk_init);
+EXPORT_SYMBOL_GPL(atmel_isc_clk_init);
 
-void isc_clk_cleanup(struct isc_device *isc)
+void atmel_isc_clk_cleanup(struct isc_device *isc)
 {
 	unsigned int i;
 
@@ -308,4 +308,4 @@ void isc_clk_cleanup(struct isc_device *isc)
 			clk_unregister(isc_clk->clk);
 	}
 }
-EXPORT_SYMBOL_GPL(isc_clk_cleanup);
+EXPORT_SYMBOL_GPL(atmel_isc_clk_cleanup);

drivers/media/platform/atmel/atmel-isc.h → drivers/staging/media/deprecated/atmel/atmel-isc.h

@@ -350,13 +350,13 @@ struct isc_device {
 	u32				formats_list_size;
 };
 
-extern const struct regmap_config isc_regmap_config;
-extern const struct v4l2_async_notifier_operations isc_async_ops;
-
-irqreturn_t isc_interrupt(int irq, void *dev_id);
-int isc_pipeline_init(struct isc_device *isc);
-int isc_clk_init(struct isc_device *isc);
-void isc_subdev_cleanup(struct isc_device *isc);
-void isc_clk_cleanup(struct isc_device *isc);
+extern const struct regmap_config atmel_isc_regmap_config;
+extern const struct v4l2_async_notifier_operations atmel_isc_async_ops;
+
+irqreturn_t atmel_isc_interrupt(int irq, void *dev_id);
+int atmel_isc_pipeline_init(struct isc_device *isc);
+int atmel_isc_clk_init(struct isc_device *isc);
+void atmel_isc_subdev_cleanup(struct isc_device *isc);
+void atmel_isc_clk_cleanup(struct isc_device *isc);
 
 #endif

drivers/media/platform/atmel/atmel-sama5d2-isc.c → drivers/staging/media/deprecated/atmel/atmel-sama5d2-isc.c

@@ -408,7 +408,7 @@ static int atmel_isc_probe(struct platform_device *pdev)
 	if (IS_ERR(io_base))
 		return PTR_ERR(io_base);
 
-	isc->regmap = devm_regmap_init_mmio(dev, io_base, &isc_regmap_config);
+	isc->regmap = devm_regmap_init_mmio(dev, io_base, &atmel_isc_regmap_config);
 	if (IS_ERR(isc->regmap)) {
 		ret = PTR_ERR(isc->regmap);
 		dev_err(dev, "failed to init register map: %d\n", ret);
@@ -419,7 +419,7 @@ static int atmel_isc_probe(struct platform_device *pdev)
 	if (irq < 0)
 		return irq;
 
-	ret = devm_request_irq(dev, irq, isc_interrupt, 0,
+	ret = devm_request_irq(dev, irq, atmel_isc_interrupt, 0,
 			       "atmel-sama5d2-isc", isc);
 	if (ret < 0) {
 		dev_err(dev, "can't register ISR for IRQ %u (ret=%i)\n",
@@ -464,7 +464,7 @@ static int atmel_isc_probe(struct platform_device *pdev)
 	/* sama5d2-isc : ISPCK is required and mandatory */
 	isc->ispck_required = true;
 
-	ret = isc_pipeline_init(isc);
+	ret = atmel_isc_pipeline_init(isc);
 	if (ret)
 		return ret;
 
@@ -481,7 +481,7 @@ static int atmel_isc_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	ret = isc_clk_init(isc);
+	ret = atmel_isc_clk_init(isc);
 	if (ret) {
 		dev_err(dev, "failed to init isc clock: %d\n", ret);
 		goto unprepare_hclk;
@@ -523,7 +523,7 @@ static int atmel_isc_probe(struct platform_device *pdev)
 			goto cleanup_subdev;
 		}
 
-		subdev_entity->notifier.ops = &isc_async_ops;
+		subdev_entity->notifier.ops = &atmel_isc_async_ops;
 
 		ret = v4l2_async_nf_register(&isc->v4l2_dev,
 					     &subdev_entity->notifier);
@@ -567,15 +567,15 @@ static int atmel_isc_probe(struct platform_device *pdev)
 	pm_runtime_disable(dev);
 
 cleanup_subdev:
-	isc_subdev_cleanup(isc);
+	atmel_isc_subdev_cleanup(isc);
 
 unregister_v4l2_device:
 	v4l2_device_unregister(&isc->v4l2_dev);
 
 unprepare_hclk:
 	clk_disable_unprepare(isc->hclock);
 
-	isc_clk_cleanup(isc);
+	atmel_isc_clk_cleanup(isc);
 
 	return ret;
 }
@@ -586,14 +586,14 @@ static int atmel_isc_remove(struct platform_device *pdev)
 
 	pm_runtime_disable(&pdev->dev);
 
-	isc_subdev_cleanup(isc);
+	atmel_isc_subdev_cleanup(isc);
 
 	v4l2_device_unregister(&isc->v4l2_dev);
 
 	clk_disable_unprepare(isc->ispck);
 	clk_disable_unprepare(isc->hclock);
 
-	isc_clk_cleanup(isc);
+	atmel_isc_clk_cleanup(isc);
 
 	return 0;
 }