Messages in this thread | | | Date | Thu, 29 Jun 2023 13:49:17 +0200 | Subject | Re: [PATCH v8 3/5] staging: bcm2835-camera: Register bcm2835-camera with vchiq_bus_type | From | Umang Jain <> |
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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 >>
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