[PATCH v2 07/15] nvmem: core: allow single and dynamic device ids

[Marco Felsch]

On 25-08-20, Sascha Hauer wrote:
> On Mon, Aug 18, 2025 at 07:44:41PM +0200, Marco Felsch wrote:
> > At the moment only DEVICE_ID_DYNAMIC is supported. Add support for
> > NVMEM_DEVID_NONE to allow static device names via of-aliases and to
> > align our core with Linux.
> > 
> > While on it fix the nvmem_register_cdev() by using the dev_name() which
> > honors the DEVICE_ID_* cases else we end up with different names for the
> > devfs and the device itself.
> > 
> > The dev_dbg() message can be dropped as well since the register_device()
> > can print this message too.
> > 
> > Signed-off-by: Marco Felsch <m.felsch at pengutronix.de>
> > ---
> >  drivers/nvmem/core.c           | 16 +++++++++++-----
> >  include/linux/nvmem-provider.h |  4 ++++
> >  2 files changed, 15 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
> > index 4dbeb1e116ae398f1f2748238d97468c1096262a..7e1dcceb00b924548b4582504b8ccaa4f29c4bdc 100644
> > --- a/drivers/nvmem/core.c
> > +++ b/drivers/nvmem/core.c
> > @@ -442,17 +442,23 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
> >  	if (config->read_only || !config->reg_write || of_property_read_bool(np, "read-only"))
> >  		nvmem->read_only = true;
> >  
> > -	dev_set_name(&nvmem->dev, "%s", config->name);
> > -	nvmem->dev.id = DEVICE_ID_DYNAMIC;
> > -
> > -	dev_dbg(nvmem->dev.parent, "Registering nvmem device %s\n", config->name);
> > +	dev_set_name(&nvmem->dev, "%s", config->name ? : "nvmem");
> > +	switch (config->id) {
> > +	case NVMEM_DEVID_NONE:
> > +		nvmem->dev.id = DEVICE_ID_SINGLE;
> > +		break;
> > +	case NVMEM_DEVID_AUTO:
> > +	default:
> > +		nvmem->dev.id = DEVICE_ID_DYNAMIC;
> > +		break;
> > +	}
> >  
> >  	rval = register_device(&nvmem->dev);
> >  	if (rval)
> >  		goto err_remove_cells;
> >  
> >  	if (!config->cdev) {
> > -		rval = nvmem_register_cdev(nvmem, config->name);
> > +		rval = nvmem_register_cdev(nvmem, dev_name(&nvmem->dev));
> 
> This change breaks the "nvmem" command and with it the nvmem test.
> "nvmem -c 1k" used to create a /dev/rmem0 cdev. With this change it
> now creates a "/dev/rmem00" cdev.

I wasn't aware of this command till now.

> I Fixed this with the following.

Thank you!

Regards,
  Marco


> 
> ---------------------------------8<-----------------------------------
> From 171ed3f457ff8ba336f0300939c3ec39a4cda5eb Mon Sep 17 00:00:00 2001
> From: Sascha Hauer <s.hauer at pengutronix.de>
> Date: Wed, 20 Aug 2025 09:28:19 +0200
> Subject: [PATCH] fixup! nvmem: core: allow single and dynamic device ids
> 
> Rename "rmem" driver to "nvmem-rmem". Without it both the rmem container
> device and the nvmem device are named "rmem" with different ids.
> 
> ---
>  commands/nvmem.c     | 2 +-
>  drivers/nvmem/rmem.c | 5 +++--
>  2 files changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/commands/nvmem.c b/commands/nvmem.c
> index 3bfa1ff19a..25f80db6fd 100644
> --- a/commands/nvmem.c
> +++ b/commands/nvmem.c
> @@ -35,7 +35,7 @@ static int nvmem_create_dynamic_rmem(unsigned long create_size,
>  	int ret = 0;
>  
>  	buffer = xzalloc(create_size);
> -	dev = add_generic_device("rmem", dynamic_rmem_idx, NULL,
> +	dev = add_generic_device("nvmem-rmem", dynamic_rmem_idx, NULL,
>  				 (resource_size_t)(uintptr_t)buffer,
>  				 (resource_size_t)create_size,
>  				 IORESOURCE_MEM, NULL);
> diff --git a/drivers/nvmem/rmem.c b/drivers/nvmem/rmem.c
> index 378a93110d..de9b7af6e4 100644
> --- a/drivers/nvmem/rmem.c
> +++ b/drivers/nvmem/rmem.c
> @@ -118,7 +118,8 @@ static int rmem_probe(struct device *dev)
>  
>  	config.dev = priv->dev = dev;
>  	config.priv = priv;
> -	config.name = dev_name(dev);
> +	config.name = "rmem";
> +	config.id = NVMEM_DEVID_AUTO;
>  	config.size = resource_size(mem);
>  	priv->size = config.size;
>  
> @@ -138,7 +139,7 @@ static const struct of_device_id rmem_match[] = {
>  MODULE_DEVICE_TABLE(of, rmem_match);
>  
>  static struct driver rmem_driver = {
> -	.name = "rmem",
> +	.name = "nvmem-rmem",
>  	.of_compatible = rmem_match,
>  	.probe = rmem_probe,
>  };
> -- 
> 2.39.5
> 
> 
> 
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