On 09.03.23 12:52, Sascha Hauer wrote:
> When devices are enabled with a device tree overlay the newly enabled
> devices can be probed by doing a of_probe(). This works fine for the
> regular platform devices, but doesn't work for devices which are not
> probed by the core, but by the subsystem. Prominent examples are I2C or
> SPI devices.
>
> This patch adds a struct device::rescan hook that subsystems can
> implement to trigger rescanning the device nodes.
>
> Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
Reviewed-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
> ---
> drivers/of/platform.c | 11 +++++------
> include/driver.h | 6 ++++++
> 2 files changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index edb082b106..2e9abe32bc 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -153,8 +153,10 @@ struct device *of_platform_device_create(struct device_node *np,
> * Linux uses the OF_POPULATED flag to skip already populated/created
> * devices.
> */
> - if (np->dev)
> + if (np->dev) {
> + device_rescan(np->dev);
> return np->dev;
> + }
>
> /* count the io resources */
> if (of_can_translate_address(np))
> @@ -420,11 +422,8 @@ static struct device *of_device_create_on_demand(struct device_node *np)
> if (!parent)
> return NULL;
>
> - if (!np->dev && parent->dev) {
> - ret = device_detect(parent->dev);
> - if (ret && ret != -ENOSYS)
> - return ERR_PTR(ret);
> - }
> + if (!np->dev && parent->dev)
> + device_rescan(parent->dev);
>
> if (!np->dev)
> pr_debug("Creating device for %s\n", np->full_name);
> diff --git a/include/driver.h b/include/driver.h
> index f53668711b..91e1f01974 100644
> --- a/include/driver.h
> +++ b/include/driver.h
> @@ -91,6 +91,7 @@ struct device {
> * when the driver should actually detect client devices
> */
> int (*detect) (struct device *);
> + void (*rescan) (struct device *);
>
> /*
> * if a driver probe is deferred, this stores the last error
> @@ -158,7 +159,12 @@ static inline void put_device(struct device *dev) {}
> void free_device_res(struct device *dev);
> void free_device(struct device *dev);
>
> +static inline void device_rescan(struct device *dev)
> +{
> + if (dev->rescan)
> + dev->rescan(dev);
>
> +}
> /* Iterate over a devices children
> */
> #define device_for_each_child(dev, child) \
--
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