[PATCH] mfd: implement mfd_add_devices

[Sascha Hauer]

On Fri, Jan 14, 2022 at 09:47:28AM +0100, Ahmad Fatoum wrote:
> This makes it easier to port Linux drivers like PMICs, where a device
> tree probed MFD node exists and the driver matching against it then
> registers a number of MFD cell devices, which don't have their own
> DT compatibles.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
> ---
>  drivers/base/resource.c  |  2 +-
>  drivers/mfd/Makefile     |  2 ++
>  drivers/mfd/core.c       | 25 +++++++++++++++++++++++++
>  include/driver.h         |  2 +-
>  include/linux/mfd/core.h | 23 +++++++++++++++++++++++
>  5 files changed, 52 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/mfd/core.c
>  create mode 100644 include/linux/mfd/core.h
> 
> diff --git a/drivers/base/resource.c b/drivers/base/resource.c
> index d0d39620772e..0134456ffac2 100644
> --- a/drivers/base/resource.c
> +++ b/drivers/base/resource.c
> @@ -20,7 +20,7 @@ struct device_d *device_alloc(const char *devname, int id)
>  	return dev;
>  }
>  
> -int device_add_data(struct device_d *dev, void *data, size_t size)
> +int device_add_data(struct device_d *dev, const void *data, size_t size)
>  {
>  	free(dev->platform_data);
>  
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 2bcf90078ab4..a00119a1d5f4 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -1,4 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0-only
> +obj-y				+= core.o
> +
>  obj-$(CONFIG_MFD_ACT8846)	+= act8846.o
>  obj-$(CONFIG_MFD_DA9053)	+= da9053.o
>  obj-$(CONFIG_MFD_DA9063)	+= da9063.o
> diff --git a/drivers/mfd/core.c b/drivers/mfd/core.c
> new file mode 100644
> index 000000000000..fa6aa1c74a18
> --- /dev/null
> +++ b/drivers/mfd/core.c
> @@ -0,0 +1,25 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#include <linux/mfd/core.h>
> +#include <driver.h>
> +
> +int mfd_add_devices(struct device_d *parent, const struct mfd_cell *cells, int n_devs)
> +{
> +	struct device_d *dev;
> +	int ret, i;
> +
> +	for (i = 0; i < n_devs; i++) {
> +		dev = device_alloc(cells[i].name, DEVICE_ID_DYNAMIC);
> +		dev->parent = parent;
> +
> +		ret = platform_device_register(dev);
> +		if (ret)
> +			return ret;
> +
> +		ret = device_add_data(dev, &cells[i], sizeof(cells[i]));
> +		if (ret)
> +			return ret;

Calling platform_device_register() might result in probing the device.
You should call device_add_data() before registering the device.

Sascha

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