Register the bcm2835-camera with the vchiq_bus_type instead of using
platform driver/device.

Also the VCHIQ firmware doesn't support device enumeration, hence
one has to maintain a list of devices to be registered in the interface.

Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
---
 .../bcm2835-camera/bcm2835-camera.c           | 16 +++++++-------
 .../interface/vchiq_arm/vchiq_arm.c           | 21 ++++++++++++++++---
 2 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
index 346d00df815a..f37b2a881d92 100644
--- a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
+++ b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
@@ -24,8 +24,9 @@
 #include <media/v4l2-event.h>
 #include <media/v4l2-common.h>
 #include <linux/delay.h>
-#include <linux/platform_device.h>
 
+#include "../interface/vchiq_arm/vchiq_arm.h"
+#include "../interface/vchiq_arm/vchiq_device.h"
 #include "../vchiq-mmal/mmal-common.h"
 #include "../vchiq-mmal/mmal-encodings.h"
 #include "../vchiq-mmal/mmal-vchiq.h"
@@ -1841,7 +1842,7 @@ static struct v4l2_format default_v4l2_format = {
 	.fmt.pix.sizeimage = 1024 * 768,
 };
 
-static int bcm2835_mmal_probe(struct platform_device *pdev)
+static int bcm2835_mmal_probe(struct vchiq_device *device)
 {
 	int ret;
 	struct bcm2835_mmal_dev *dev;
@@ -1896,7 +1897,7 @@ static int bcm2835_mmal_probe(struct platform_device *pdev)
 						       &camera_instance);
 		ret = v4l2_device_register(NULL, &dev->v4l2_dev);
 		if (ret) {
-			dev_err(&pdev->dev, "%s: could not register V4L2 device: %d\n",
+			dev_err(&device->dev, "%s: could not register V4L2 device: %d\n",
 				__func__, ret);
 			goto free_dev;
 		}
@@ -1976,7 +1977,7 @@ static int bcm2835_mmal_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static void bcm2835_mmal_remove(struct platform_device *pdev)
+static void bcm2835_mmal_remove(struct vchiq_device *device)
 {
 	int camera;
 	struct vchiq_mmal_instance *instance = gdev[0]->instance;
@@ -1988,17 +1989,16 @@ static void bcm2835_mmal_remove(struct platform_device *pdev)
 	vchiq_mmal_finalise(instance);
 }
 
-static struct platform_driver bcm2835_camera_driver = {
+static struct vchiq_driver bcm2835_camera_driver = {
 	.probe		= bcm2835_mmal_probe,
-	.remove_new	= bcm2835_mmal_remove,
+	.remove		= bcm2835_mmal_remove,
 	.driver		= {
 		.name	= "bcm2835-camera",
 	},
 };
 
-module_platform_driver(bcm2835_camera_driver)
+module_vchiq_driver(bcm2835_camera_driver)
 
 MODULE_DESCRIPTION("Broadcom 2835 MMAL video capture");
 MODULE_AUTHOR("Vincent Sanders");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:bcm2835-camera");
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index e8d40f891449..79d4d0eeb5fb 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -67,7 +67,6 @@ int vchiq_susp_log_level = VCHIQ_LOG_ERROR;
 DEFINE_SPINLOCK(msg_queue_spinlock);
 struct vchiq_state g_state;
 
-static struct platform_device *bcm2835_camera;
 static struct platform_device *bcm2835_audio;
 
 struct vchiq_drvdata {
@@ -134,6 +133,15 @@ struct vchiq_pagelist_info {
 	unsigned int scatterlist_mapped;
 };
 
+/*
+ * The devices implemented in the VCHIQ firmware are not discoverable,
+ * so we need to maintain a list of them in order to register them with
+ * the interface.
+ */
+static const char *const vchiq_devices[] = {
+	"bcm2835-camera",
+};
+
 static void __iomem *g_regs;
 /* This value is the size of the L2 cache lines as understood by the
  * VPU firmware, which determines the required alignment of the
@@ -1798,6 +1806,7 @@ static int vchiq_probe(struct platform_device *pdev)
 	struct device_node *fw_node;
 	const struct of_device_id *of_id;
 	struct vchiq_drvdata *drvdata;
+	unsigned int i;
 	int err;
 
 	of_id = of_match_node(vchiq_of_match, pdev->dev.of_node);
@@ -1840,9 +1849,15 @@ static int vchiq_probe(struct platform_device *pdev)
 		goto error_exit;
 	}
 
-	bcm2835_camera = vchiq_register_child(pdev, "bcm2835-camera");
 	bcm2835_audio = vchiq_register_child(pdev, "bcm2835_audio");
 
+	for (i = 0; i < ARRAY_SIZE(vchiq_devices); i++) {
+		err = vchiq_device_register(&pdev->dev, vchiq_devices[i]);
+		if (err)
+			dev_err(&pdev->dev, "Failed to register %s vchiq device\n",
+			vchiq_devices[i]);
+	}
+
 	return 0;
 
 failed_platform_init:
@@ -1854,7 +1869,7 @@ static int vchiq_probe(struct platform_device *pdev)
 static void vchiq_remove(struct platform_device *pdev)
 {
 	platform_device_unregister(bcm2835_audio);
-	platform_device_unregister(bcm2835_camera);
+	bus_for_each_dev(&vchiq_bus_type, NULL, NULL, vchiq_device_unregister);
 	vchiq_debugfs_deinit();
 	vchiq_deregister_chrdev();
 }
-- 
2.39.1

Quoting Umang Jain (2023-06-27 21:16:26)
> Register the bcm2835-camera with the vchiq_bus_type instead of using
> platform driver/device.
> 
> Also the VCHIQ firmware doesn't support device enumeration, hence
> one has to maintain a list of devices to be registered in the interface.
> 
> Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
> ---
>  .../bcm2835-camera/bcm2835-camera.c           | 16 +++++++-------
>  .../interface/vchiq_arm/vchiq_arm.c           | 21 ++++++++++++++++---
>  2 files changed, 26 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
> index 346d00df815a..f37b2a881d92 100644
> --- a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
> +++ b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
> @@ -24,8 +24,9 @@
>  #include <media/v4l2-event.h>
>  #include <media/v4l2-common.h>
>  #include <linux/delay.h>
> -#include <linux/platform_device.h>
>  
> +#include "../interface/vchiq_arm/vchiq_arm.h"
> +#include "../interface/vchiq_arm/vchiq_device.h"
>  #include "../vchiq-mmal/mmal-common.h"
>  #include "../vchiq-mmal/mmal-encodings.h"
>  #include "../vchiq-mmal/mmal-vchiq.h"
> @@ -1841,7 +1842,7 @@ static struct v4l2_format default_v4l2_format = {
>         .fmt.pix.sizeimage = 1024 * 768,
>  };
>  
> -static int bcm2835_mmal_probe(struct platform_device *pdev)
> +static int bcm2835_mmal_probe(struct vchiq_device *device)
>  {
>         int ret;
>         struct bcm2835_mmal_dev *dev;
> @@ -1896,7 +1897,7 @@ static int bcm2835_mmal_probe(struct platform_device *pdev)
>                                                        &camera_instance);
>                 ret = v4l2_device_register(NULL, &dev->v4l2_dev);
>                 if (ret) {
> -                       dev_err(&pdev->dev, "%s: could not register V4L2 device: %d\n",
> +                       dev_err(&device->dev, "%s: could not register V4L2 device: %d\n",
>                                 __func__, ret);
>                         goto free_dev;
>                 }
> @@ -1976,7 +1977,7 @@ static int bcm2835_mmal_probe(struct platform_device *pdev)
>         return ret;
>  }
>  
> -static void bcm2835_mmal_remove(struct platform_device *pdev)
> +static void bcm2835_mmal_remove(struct vchiq_device *device)
>  {
>         int camera;
>         struct vchiq_mmal_instance *instance = gdev[0]->instance;
> @@ -1988,17 +1989,16 @@ static void bcm2835_mmal_remove(struct platform_device *pdev)
>         vchiq_mmal_finalise(instance);
>  }
>  
> -static struct platform_driver bcm2835_camera_driver = {
> +static struct vchiq_driver bcm2835_camera_driver = {
>         .probe          = bcm2835_mmal_probe,
> -       .remove_new     = bcm2835_mmal_remove,
> +       .remove         = bcm2835_mmal_remove,
>         .driver         = {
>                 .name   = "bcm2835-camera",
>         },
>  };
>  
> -module_platform_driver(bcm2835_camera_driver)
> +module_vchiq_driver(bcm2835_camera_driver)
>  
>  MODULE_DESCRIPTION("Broadcom 2835 MMAL video capture");
>  MODULE_AUTHOR("Vincent Sanders");
>  MODULE_LICENSE("GPL");
> -MODULE_ALIAS("platform:bcm2835-camera");

This bit worries me. I think that's how module autoloading is handled.

Can you check into the details of MODULE_ALIAS and follow the rabbit
hole for a bit? It's a few years since I last went down there so I can't
remember the specifics right now.

Except for that, I think this looks good.


> diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
> index e8d40f891449..79d4d0eeb5fb 100644
> --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
> +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
> @@ -67,7 +67,6 @@ int vchiq_susp_log_level = VCHIQ_LOG_ERROR;
>  DEFINE_SPINLOCK(msg_queue_spinlock);
>  struct vchiq_state g_state;
>  
> -static struct platform_device *bcm2835_camera;
>  static struct platform_device *bcm2835_audio;
>  
>  struct vchiq_drvdata {
> @@ -134,6 +133,15 @@ struct vchiq_pagelist_info {
>         unsigned int scatterlist_mapped;
>  };
>  
> +/*
> + * The devices implemented in the VCHIQ firmware are not discoverable,
> + * so we need to maintain a list of them in order to register them with
> + * the interface.
> + */
> +static const char *const vchiq_devices[] = {
> +       "bcm2835-camera",
> +};
> +
>  static void __iomem *g_regs;
>  /* This value is the size of the L2 cache lines as understood by the
>   * VPU firmware, which determines the required alignment of the
> @@ -1798,6 +1806,7 @@ static int vchiq_probe(struct platform_device *pdev)
>         struct device_node *fw_node;
>         const struct of_device_id *of_id;
>         struct vchiq_drvdata *drvdata;
> +       unsigned int i;
>         int err;
>  
>         of_id = of_match_node(vchiq_of_match, pdev->dev.of_node);
> @@ -1840,9 +1849,15 @@ static int vchiq_probe(struct platform_device *pdev)
>                 goto error_exit;
>         }
>  
> -       bcm2835_camera = vchiq_register_child(pdev, "bcm2835-camera");
>         bcm2835_audio = vchiq_register_child(pdev, "bcm2835_audio");
>  
> +       for (i = 0; i < ARRAY_SIZE(vchiq_devices); i++) {
> +               err = vchiq_device_register(&pdev->dev, vchiq_devices[i]);
> +               if (err)
> +                       dev_err(&pdev->dev, "Failed to register %s vchiq device\n",
> +                       vchiq_devices[i]);
> +       }
> +
>         return 0;
>  
>  failed_platform_init:
> @@ -1854,7 +1869,7 @@ static int vchiq_probe(struct platform_device *pdev)
>  static void vchiq_remove(struct platform_device *pdev)
>  {
>         platform_device_unregister(bcm2835_audio);
> -       platform_device_unregister(bcm2835_camera);
> +       bus_for_each_dev(&vchiq_bus_type, NULL, NULL, vchiq_device_unregister);
>         vchiq_debugfs_deinit();
>         vchiq_deregister_chrdev();
>  }
> -- 
> 2.39.1
>

Hi Kieran,

On 6/29/23 12:44 AM, Kieran Bingham wrote:
> Quoting Umang Jain (2023-06-27 21:16:26)
>> Register the bcm2835-camera with the vchiq_bus_type instead of using
>> platform driver/device.
>>
>> Also the VCHIQ firmware doesn't support device enumeration, hence
>> one has to maintain a list of devices to be registered in the interface.
>>
>> Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
>> ---
>>   .../bcm2835-camera/bcm2835-camera.c           | 16 +++++++-------
>>   .../interface/vchiq_arm/vchiq_arm.c           | 21 ++++++++++++++++---
>>   2 files changed, 26 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
>> index 346d00df815a..f37b2a881d92 100644
>> --- a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
>> +++ b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
>> @@ -24,8 +24,9 @@
>>   #include <media/v4l2-event.h>
>>   #include <media/v4l2-common.h>
>>   #include <linux/delay.h>
>> -#include <linux/platform_device.h>
>>   
>> +#include "../interface/vchiq_arm/vchiq_arm.h"
>> +#include "../interface/vchiq_arm/vchiq_device.h"
>>   #include "../vchiq-mmal/mmal-common.h"
>>   #include "../vchiq-mmal/mmal-encodings.h"
>>   #include "../vchiq-mmal/mmal-vchiq.h"
>> @@ -1841,7 +1842,7 @@ static struct v4l2_format default_v4l2_format = {
>>          .fmt.pix.sizeimage = 1024 * 768,
>>   };
>>   
>> -static int bcm2835_mmal_probe(struct platform_device *pdev)
>> +static int bcm2835_mmal_probe(struct vchiq_device *device)
>>   {
>>          int ret;
>>          struct bcm2835_mmal_dev *dev;
>> @@ -1896,7 +1897,7 @@ static int bcm2835_mmal_probe(struct platform_device *pdev)
>>                                                         &camera_instance);
>>                  ret = v4l2_device_register(NULL, &dev->v4l2_dev);
>>                  if (ret) {
>> -                       dev_err(&pdev->dev, "%s: could not register V4L2 device: %d\n",
>> +                       dev_err(&device->dev, "%s: could not register V4L2 device: %d\n",
>>                                  __func__, ret);
>>                          goto free_dev;
>>                  }
>> @@ -1976,7 +1977,7 @@ static int bcm2835_mmal_probe(struct platform_device *pdev)
>>          return ret;
>>   }
>>   
>> -static void bcm2835_mmal_remove(struct platform_device *pdev)
>> +static void bcm2835_mmal_remove(struct vchiq_device *device)
>>   {
>>          int camera;
>>          struct vchiq_mmal_instance *instance = gdev[0]->instance;
>> @@ -1988,17 +1989,16 @@ static void bcm2835_mmal_remove(struct platform_device *pdev)
>>          vchiq_mmal_finalise(instance);
>>   }
>>   
>> -static struct platform_driver bcm2835_camera_driver = {
>> +static struct vchiq_driver bcm2835_camera_driver = {
>>          .probe          = bcm2835_mmal_probe,
>> -       .remove_new     = bcm2835_mmal_remove,
>> +       .remove         = bcm2835_mmal_remove,
>>          .driver         = {
>>                  .name   = "bcm2835-camera",
>>          },
>>   };
>>   
>> -module_platform_driver(bcm2835_camera_driver)
>> +module_vchiq_driver(bcm2835_camera_driver)
>>   
>>   MODULE_DESCRIPTION("Broadcom 2835 MMAL video capture");
>>   MODULE_AUTHOR("Vincent Sanders");
>>   MODULE_LICENSE("GPL");
>> -MODULE_ALIAS("platform:bcm2835-camera");
> This bit worries me. I think that's how module autoloading is handled.
>
> Can you check into the details of MODULE_ALIAS and follow the rabbit
> hole for a bit? It's a few years since I last went down there so I can't
> remember the specifics right now.

vchiq_probe() will register both the bcm2385_audio and bcm2835-camera 
hence, we don't need MODULE_ALIAS for those two.

So what I also tested is that, when bcm2835_vchiq loads, it will 
auto-load both audio and camera with it (since these are child devices 
of vchiq). I think that's the correct way.
>
> Except for that, I think this looks good.
>
>
>> diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
>> index e8d40f891449..79d4d0eeb5fb 100644
>> --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
>> +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
>> @@ -67,7 +67,6 @@ int vchiq_susp_log_level = VCHIQ_LOG_ERROR;
>>   DEFINE_SPINLOCK(msg_queue_spinlock);
>>   struct vchiq_state g_state;
>>   
>> -static struct platform_device *bcm2835_camera;
>>   static struct platform_device *bcm2835_audio;
>>   
>>   struct vchiq_drvdata {
>> @@ -134,6 +133,15 @@ struct vchiq_pagelist_info {
>>          unsigned int scatterlist_mapped;
>>   };
>>   
>> +/*
>> + * The devices implemented in the VCHIQ firmware are not discoverable,
>> + * so we need to maintain a list of them in order to register them with
>> + * the interface.
>> + */
>> +static const char *const vchiq_devices[] = {
>> +       "bcm2835-camera",
>> +};
>> +
>>   static void __iomem *g_regs;
>>   /* This value is the size of the L2 cache lines as understood by the
>>    * VPU firmware, which determines the required alignment of the
>> @@ -1798,6 +1806,7 @@ static int vchiq_probe(struct platform_device *pdev)
>>          struct device_node *fw_node;
>>          const struct of_device_id *of_id;
>>          struct vchiq_drvdata *drvdata;
>> +       unsigned int i;
>>          int err;
>>   
>>          of_id = of_match_node(vchiq_of_match, pdev->dev.of_node);
>> @@ -1840,9 +1849,15 @@ static int vchiq_probe(struct platform_device *pdev)
>>                  goto error_exit;
>>          }
>>   
>> -       bcm2835_camera = vchiq_register_child(pdev, "bcm2835-camera");
>>          bcm2835_audio = vchiq_register_child(pdev, "bcm2835_audio");
>>   
>> +       for (i = 0; i < ARRAY_SIZE(vchiq_devices); i++) {
>> +               err = vchiq_device_register(&pdev->dev, vchiq_devices[i]);
>> +               if (err)
>> +                       dev_err(&pdev->dev, "Failed to register %s vchiq device\n",
>> +                       vchiq_devices[i]);
>> +       }
>> +
>>          return 0;
>>   
>>   failed_platform_init:
>> @@ -1854,7 +1869,7 @@ static int vchiq_probe(struct platform_device *pdev)
>>   static void vchiq_remove(struct platform_device *pdev)
>>   {
>>          platform_device_unregister(bcm2835_audio);
>> -       platform_device_unregister(bcm2835_camera);
>> +       bus_for_each_dev(&vchiq_bus_type, NULL, NULL, vchiq_device_unregister);
>>          vchiq_debugfs_deinit();
>>          vchiq_deregister_chrdev();
>>   }
>> -- 
>> 2.39.1
>>

Quoting Umang Jain (2023-06-29 12:49:17)
> Hi Kieran,
> 
> On 6/29/23 12:44 AM, Kieran Bingham wrote:
> > Quoting Umang Jain (2023-06-27 21:16:26)
> >> Register the bcm2835-camera with the vchiq_bus_type instead of using
> >> platform driver/device.
> >>
> >> Also the VCHIQ firmware doesn't support device enumeration, hence
> >> one has to maintain a list of devices to be registered in the interface.
> >>
> >> Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
> >> ---
> >>   .../bcm2835-camera/bcm2835-camera.c           | 16 +++++++-------
> >>   .../interface/vchiq_arm/vchiq_arm.c           | 21 ++++++++++++++++---
> >>   2 files changed, 26 insertions(+), 11 deletions(-)
> >>
> >> diff --git a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
> >> index 346d00df815a..f37b2a881d92 100644
> >> --- a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
> >> +++ b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
> >> @@ -24,8 +24,9 @@
> >>   #include <media/v4l2-event.h>
> >>   #include <media/v4l2-common.h>
> >>   #include <linux/delay.h>
> >> -#include <linux/platform_device.h>
> >>   
> >> +#include "../interface/vchiq_arm/vchiq_arm.h"
> >> +#include "../interface/vchiq_arm/vchiq_device.h"
> >>   #include "../vchiq-mmal/mmal-common.h"
> >>   #include "../vchiq-mmal/mmal-encodings.h"
> >>   #include "../vchiq-mmal/mmal-vchiq.h"
> >> @@ -1841,7 +1842,7 @@ static struct v4l2_format default_v4l2_format = {
> >>          .fmt.pix.sizeimage = 1024 * 768,
> >>   };
> >>   
> >> -static int bcm2835_mmal_probe(struct platform_device *pdev)
> >> +static int bcm2835_mmal_probe(struct vchiq_device *device)
> >>   {
> >>          int ret;
> >>          struct bcm2835_mmal_dev *dev;
> >> @@ -1896,7 +1897,7 @@ static int bcm2835_mmal_probe(struct platform_device *pdev)
> >>                                                         &camera_instance);
> >>                  ret = v4l2_device_register(NULL, &dev->v4l2_dev);
> >>                  if (ret) {
> >> -                       dev_err(&pdev->dev, "%s: could not register V4L2 device: %d\n",
> >> +                       dev_err(&device->dev, "%s: could not register V4L2 device: %d\n",
> >>                                  __func__, ret);
> >>                          goto free_dev;
> >>                  }
> >> @@ -1976,7 +1977,7 @@ static int bcm2835_mmal_probe(struct platform_device *pdev)
> >>          return ret;
> >>   }
> >>   
> >> -static void bcm2835_mmal_remove(struct platform_device *pdev)
> >> +static void bcm2835_mmal_remove(struct vchiq_device *device)
> >>   {
> >>          int camera;
> >>          struct vchiq_mmal_instance *instance = gdev[0]->instance;
> >> @@ -1988,17 +1989,16 @@ static void bcm2835_mmal_remove(struct platform_device *pdev)
> >>          vchiq_mmal_finalise(instance);
> >>   }
> >>   
> >> -static struct platform_driver bcm2835_camera_driver = {
> >> +static struct vchiq_driver bcm2835_camera_driver = {
> >>          .probe          = bcm2835_mmal_probe,
> >> -       .remove_new     = bcm2835_mmal_remove,
> >> +       .remove         = bcm2835_mmal_remove,
> >>          .driver         = {
> >>                  .name   = "bcm2835-camera",
> >>          },
> >>   };
> >>   
> >> -module_platform_driver(bcm2835_camera_driver)
> >> +module_vchiq_driver(bcm2835_camera_driver)
> >>   
> >>   MODULE_DESCRIPTION("Broadcom 2835 MMAL video capture");
> >>   MODULE_AUTHOR("Vincent Sanders");
> >>   MODULE_LICENSE("GPL");
> >> -MODULE_ALIAS("platform:bcm2835-camera");
> > This bit worries me. I think that's how module autoloading is handled.
> >
> > Can you check into the details of MODULE_ALIAS and follow the rabbit
> > hole for a bit? It's a few years since I last went down there so I can't
> > remember the specifics right now.
> 
> vchiq_probe() will register both the bcm2385_audio and bcm2835-camera 
> hence, we don't need MODULE_ALIAS for those two.

It registers the devices, but I thought MODULE_ALIAS was how that gets
tied to which module to load (when drivers are built as modules).

> So what I also tested is that, when bcm2835_vchiq loads, it will 
> auto-load both audio and camera with it (since these are child devices 
> of vchiq). I think that's the correct way.

Could you test a build with the following (two) configurations please?

1)
  CONFIG_BCM2835_VCHIQ=y
  CONFIG_VIDEO_BCM2835=m
  CONFIG_SND_BCM2835=m

2)
  CONFIG_BCM2835_VCHIQ=m
  CONFIG_VIDEO_BCM2835=m
  CONFIG_SND_BCM2835=m




> >
> > Except for that, I think this looks good.
> >
> >
> >> diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
> >> index e8d40f891449..79d4d0eeb5fb 100644
> >> --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
> >> +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
> >> @@ -67,7 +67,6 @@ int vchiq_susp_log_level = VCHIQ_LOG_ERROR;
> >>   DEFINE_SPINLOCK(msg_queue_spinlock);
> >>   struct vchiq_state g_state;
> >>   
> >> -static struct platform_device *bcm2835_camera;
> >>   static struct platform_device *bcm2835_audio;
> >>   
> >>   struct vchiq_drvdata {
> >> @@ -134,6 +133,15 @@ struct vchiq_pagelist_info {
> >>          unsigned int scatterlist_mapped;
> >>   };
> >>   
> >> +/*
> >> + * The devices implemented in the VCHIQ firmware are not discoverable,
> >> + * so we need to maintain a list of them in order to register them with
> >> + * the interface.
> >> + */
> >> +static const char *const vchiq_devices[] = {
> >> +       "bcm2835-camera",
> >> +};
> >> +
> >>   static void __iomem *g_regs;
> >>   /* This value is the size of the L2 cache lines as understood by the
> >>    * VPU firmware, which determines the required alignment of the
> >> @@ -1798,6 +1806,7 @@ static int vchiq_probe(struct platform_device *pdev)
> >>          struct device_node *fw_node;
> >>          const struct of_device_id *of_id;
> >>          struct vchiq_drvdata *drvdata;
> >> +       unsigned int i;
> >>          int err;
> >>   
> >>          of_id = of_match_node(vchiq_of_match, pdev->dev.of_node);
> >> @@ -1840,9 +1849,15 @@ static int vchiq_probe(struct platform_device *pdev)
> >>                  goto error_exit;
> >>          }
> >>   
> >> -       bcm2835_camera = vchiq_register_child(pdev, "bcm2835-camera");
> >>          bcm2835_audio = vchiq_register_child(pdev, "bcm2835_audio");
> >>   
> >> +       for (i = 0; i < ARRAY_SIZE(vchiq_devices); i++) {
> >> +               err = vchiq_device_register(&pdev->dev, vchiq_devices[i]);
> >> +               if (err)
> >> +                       dev_err(&pdev->dev, "Failed to register %s vchiq device\n",
> >> +                       vchiq_devices[i]);
> >> +       }
> >> +
> >>          return 0;
> >>   
> >>   failed_platform_init:
> >> @@ -1854,7 +1869,7 @@ static int vchiq_probe(struct platform_device *pdev)
> >>   static void vchiq_remove(struct platform_device *pdev)
> >>   {
> >>          platform_device_unregister(bcm2835_audio);
> >> -       platform_device_unregister(bcm2835_camera);
> >> +       bus_for_each_dev(&vchiq_bus_type, NULL, NULL, vchiq_device_unregister);
> >>          vchiq_debugfs_deinit();
> >>          vchiq_deregister_chrdev();
> >>   }
> >> -- 
> >> 2.39.1
> >>
>

On Tue, Jun 27, 2023 at 10:16:26PM +0200, Umang Jain wrote:
> Register the bcm2835-camera with the vchiq_bus_type instead of using
> platform driver/device.
> 
> Also the VCHIQ firmware doesn't support device enumeration, hence
> one has to maintain a list of devices to be registered in the interface.
> 
> Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
> ---
>  .../bcm2835-camera/bcm2835-camera.c           | 16 +++++++-------
>  .../interface/vchiq_arm/vchiq_arm.c           | 21 ++++++++++++++++---
>  2 files changed, 26 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
> index 346d00df815a..f37b2a881d92 100644
> --- a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
> +++ b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
> @@ -24,8 +24,9 @@
>  #include <media/v4l2-event.h>
>  #include <media/v4l2-common.h>
>  #include <linux/delay.h>
> -#include <linux/platform_device.h>
>  
> +#include "../interface/vchiq_arm/vchiq_arm.h"
> +#include "../interface/vchiq_arm/vchiq_device.h"
>  #include "../vchiq-mmal/mmal-common.h"
>  #include "../vchiq-mmal/mmal-encodings.h"
>  #include "../vchiq-mmal/mmal-vchiq.h"
> @@ -1841,7 +1842,7 @@ static struct v4l2_format default_v4l2_format = {
>  	.fmt.pix.sizeimage = 1024 * 768,
>  };
>  
> -static int bcm2835_mmal_probe(struct platform_device *pdev)
> +static int bcm2835_mmal_probe(struct vchiq_device *device)
>  {
>  	int ret;
>  	struct bcm2835_mmal_dev *dev;
> @@ -1896,7 +1897,7 @@ static int bcm2835_mmal_probe(struct platform_device *pdev)
>  						       &camera_instance);
>  		ret = v4l2_device_register(NULL, &dev->v4l2_dev);
>  		if (ret) {
> -			dev_err(&pdev->dev, "%s: could not register V4L2 device: %d\n",
> +			dev_err(&device->dev, "%s: could not register V4L2 device: %d\n",
>  				__func__, ret);
>  			goto free_dev;
>  		}
> @@ -1976,7 +1977,7 @@ static int bcm2835_mmal_probe(struct platform_device *pdev)
>  	return ret;
>  }
>  
> -static void bcm2835_mmal_remove(struct platform_device *pdev)
> +static void bcm2835_mmal_remove(struct vchiq_device *device)
>  {
>  	int camera;
>  	struct vchiq_mmal_instance *instance = gdev[0]->instance;
> @@ -1988,17 +1989,16 @@ static void bcm2835_mmal_remove(struct platform_device *pdev)
>  	vchiq_mmal_finalise(instance);
>  }
>  
> -static struct platform_driver bcm2835_camera_driver = {
> +static struct vchiq_driver bcm2835_camera_driver = {
>  	.probe		= bcm2835_mmal_probe,
> -	.remove_new	= bcm2835_mmal_remove,
> +	.remove		= bcm2835_mmal_remove,

No need to change this here, right?  That's independant of this patch
series.

thanks,

greg k-h

Hi Greg,

On 7/3/23 3:29 PM, Greg KH wrote:
> On Tue, Jun 27, 2023 at 10:16:26PM +0200, Umang Jain wrote:
>> Register the bcm2835-camera with the vchiq_bus_type instead of using
>> platform driver/device.
>>
>> Also the VCHIQ firmware doesn't support device enumeration, hence
>> one has to maintain a list of devices to be registered in the interface.
>>
>> Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
>> ---
>>   .../bcm2835-camera/bcm2835-camera.c           | 16 +++++++-------
>>   .../interface/vchiq_arm/vchiq_arm.c           | 21 ++++++++++++++++---
>>   2 files changed, 26 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
>> index 346d00df815a..f37b2a881d92 100644
>> --- a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
>> +++ b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
>> @@ -24,8 +24,9 @@
>>   #include <media/v4l2-event.h>
>>   #include <media/v4l2-common.h>
>>   #include <linux/delay.h>
>> -#include <linux/platform_device.h>
>>   
>> +#include "../interface/vchiq_arm/vchiq_arm.h"
>> +#include "../interface/vchiq_arm/vchiq_device.h"
>>   #include "../vchiq-mmal/mmal-common.h"
>>   #include "../vchiq-mmal/mmal-encodings.h"
>>   #include "../vchiq-mmal/mmal-vchiq.h"
>> @@ -1841,7 +1842,7 @@ static struct v4l2_format default_v4l2_format = {
>>   	.fmt.pix.sizeimage = 1024 * 768,
>>   };
>>   
>> -static int bcm2835_mmal_probe(struct platform_device *pdev)
>> +static int bcm2835_mmal_probe(struct vchiq_device *device)
>>   {
>>   	int ret;
>>   	struct bcm2835_mmal_dev *dev;
>> @@ -1896,7 +1897,7 @@ static int bcm2835_mmal_probe(struct platform_device *pdev)
>>   						       &camera_instance);
>>   		ret = v4l2_device_register(NULL, &dev->v4l2_dev);
>>   		if (ret) {
>> -			dev_err(&pdev->dev, "%s: could not register V4L2 device: %d\n",
>> +			dev_err(&device->dev, "%s: could not register V4L2 device: %d\n",
>>   				__func__, ret);
>>   			goto free_dev;
>>   		}
>> @@ -1976,7 +1977,7 @@ static int bcm2835_mmal_probe(struct platform_device *pdev)
>>   	return ret;
>>   }
>>   
>> -static void bcm2835_mmal_remove(struct platform_device *pdev)
>> +static void bcm2835_mmal_remove(struct vchiq_device *device)
>>   {
>>   	int camera;
>>   	struct vchiq_mmal_instance *instance = gdev[0]->instance;
>> @@ -1988,17 +1989,16 @@ static void bcm2835_mmal_remove(struct platform_device *pdev)
>>   	vchiq_mmal_finalise(instance);
>>   }
>>   
>> -static struct platform_driver bcm2835_camera_driver = {
>> +static struct vchiq_driver bcm2835_camera_driver = {
>>   	.probe		= bcm2835_mmal_probe,
>> -	.remove_new	= bcm2835_mmal_remove,
>> +	.remove		= bcm2835_mmal_remove,
> No need to change this here, right?  That's independant of this patch
> series.

Why not ?

Should I have "remove_new()"  in the struct vchiq_driver {..} [Patch 
1/5] instead of "remove()"  -  match up with platform_driver virtual 
interface ?

>
> thanks,
>
> greg k-h

On Mon, Jul 03, 2023 at 04:44:39PM +0200, Umang Jain wrote:
> Hi Greg,
> 
> On 7/3/23 3:29 PM, Greg KH wrote:
> > On Tue, Jun 27, 2023 at 10:16:26PM +0200, Umang Jain wrote:
> > > Register the bcm2835-camera with the vchiq_bus_type instead of using
> > > platform driver/device.
> > > 
> > > Also the VCHIQ firmware doesn't support device enumeration, hence
> > > one has to maintain a list of devices to be registered in the interface.
> > > 
> > > Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
> > > ---
> > >   .../bcm2835-camera/bcm2835-camera.c           | 16 +++++++-------
> > >   .../interface/vchiq_arm/vchiq_arm.c           | 21 ++++++++++++++++---
> > >   2 files changed, 26 insertions(+), 11 deletions(-)
> > > 
> > > diff --git a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
> > > index 346d00df815a..f37b2a881d92 100644
> > > --- a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
> > > +++ b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
> > > @@ -24,8 +24,9 @@
> > >   #include <media/v4l2-event.h>
> > >   #include <media/v4l2-common.h>
> > >   #include <linux/delay.h>
> > > -#include <linux/platform_device.h>
> > > +#include "../interface/vchiq_arm/vchiq_arm.h"
> > > +#include "../interface/vchiq_arm/vchiq_device.h"
> > >   #include "../vchiq-mmal/mmal-common.h"
> > >   #include "../vchiq-mmal/mmal-encodings.h"
> > >   #include "../vchiq-mmal/mmal-vchiq.h"
> > > @@ -1841,7 +1842,7 @@ static struct v4l2_format default_v4l2_format = {
> > >   	.fmt.pix.sizeimage = 1024 * 768,
> > >   };
> > > -static int bcm2835_mmal_probe(struct platform_device *pdev)
> > > +static int bcm2835_mmal_probe(struct vchiq_device *device)
> > >   {
> > >   	int ret;
> > >   	struct bcm2835_mmal_dev *dev;
> > > @@ -1896,7 +1897,7 @@ static int bcm2835_mmal_probe(struct platform_device *pdev)
> > >   						       &camera_instance);
> > >   		ret = v4l2_device_register(NULL, &dev->v4l2_dev);
> > >   		if (ret) {
> > > -			dev_err(&pdev->dev, "%s: could not register V4L2 device: %d\n",
> > > +			dev_err(&device->dev, "%s: could not register V4L2 device: %d\n",
> > >   				__func__, ret);
> > >   			goto free_dev;
> > >   		}
> > > @@ -1976,7 +1977,7 @@ static int bcm2835_mmal_probe(struct platform_device *pdev)
> > >   	return ret;
> > >   }
> > > -static void bcm2835_mmal_remove(struct platform_device *pdev)
> > > +static void bcm2835_mmal_remove(struct vchiq_device *device)
> > >   {
> > >   	int camera;
> > >   	struct vchiq_mmal_instance *instance = gdev[0]->instance;
> > > @@ -1988,17 +1989,16 @@ static void bcm2835_mmal_remove(struct platform_device *pdev)
> > >   	vchiq_mmal_finalise(instance);
> > >   }
> > > -static struct platform_driver bcm2835_camera_driver = {
> > > +static struct vchiq_driver bcm2835_camera_driver = {
> > >   	.probe		= bcm2835_mmal_probe,
> > > -	.remove_new	= bcm2835_mmal_remove,
> > > +	.remove		= bcm2835_mmal_remove,
> > No need to change this here, right?  That's independant of this patch
> > series.
> 
> Why not ?
> 
> Should I have "remove_new()"  in the struct vchiq_driver {..} [Patch 1/5]
> instead of "remove()"  -  match up with platform_driver virtual interface ?

Ah, sorry, my fault, I thought this was just a platform driver change.
This is fine.

greg k-h