Re: [PATCH v2 1/2] Port SoC framework from Linux

[Sascha Hauer <sha@pengutronix.de>]

Hi Marco,

Looks good to me. Can you rebase on current master?

Sascha

On Tue, Jan 16, 2024 at 06:10:25PM +0100, Marco Felsch wrote:
> This adds the initial support for the Linux soc framework which can be
> used to register all SoC relevant informations. The framework can be
> used by driver to check for errata for an specific soc(-revision) in the
> future since this require porting the matching function.
> 
> For now it gathers all required SoC information and provide a standard
> interface to query the data via device params.
> 
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> ---
> Changelog:
> v2:
>  - nothing
> 
>  drivers/base/Kconfig    |   3 +
>  drivers/base/Makefile   |   1 +
>  drivers/base/soc.c      | 123 ++++++++++++++++++++++++++++++++++++++++
>  include/linux/sys_soc.h |  39 +++++++++++++
>  4 files changed, 166 insertions(+)
>  create mode 100644 drivers/base/soc.c
>  create mode 100644 include/linux/sys_soc.h
> 
> diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
> index 612a84be33e7..21a4793cfa47 100644
> --- a/drivers/base/Kconfig
> +++ b/drivers/base/Kconfig
> @@ -6,4 +6,7 @@ config PM_GENERIC_DOMAINS
>  config FEATURE_CONTROLLER
>  	bool "Feature controller support" if COMPILE_TEST || SANDBOX
>  
> +config SOC_BUS
> +	bool
> +
>  source "drivers/base/regmap/Kconfig"
> diff --git a/drivers/base/Makefile b/drivers/base/Makefile
> index e8e354cdaabc..acc53763da35 100644
> --- a/drivers/base/Makefile
> +++ b/drivers/base/Makefile
> @@ -7,3 +7,4 @@ obj-y	+= regmap/
>  
>  obj-$(CONFIG_PM_GENERIC_DOMAINS) += power.o
>  obj-$(CONFIG_FEATURE_CONTROLLER) += featctrl.o
> +obj-$(CONFIG_SOC_BUS) += soc.o
> diff --git a/drivers/base/soc.c b/drivers/base/soc.c
> new file mode 100644
> index 000000000000..a481f8987b56
> --- /dev/null
> +++ b/drivers/base/soc.c
> @@ -0,0 +1,123 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +// SPDX-FileCopyrightText: 2024 Marco Felsch, Pengutronix
> +/*
> + * Based on Linux drivers/base/soc.c:
> + * Copyright (C) ST-Ericsson SA 2011
> + */
> +
> +#include <common.h>
> +#include <init.h>
> +#include <of.h>
> +
> +#include <linux/slab.h>
> +#include <linux/sys_soc.h>
> +#include <linux/err.h>
> +
> +struct soc_device {
> +	struct device dev;
> +	struct soc_device_attribute *attr;
> +};
> +
> +static struct bus_type soc_bus_type = {
> +	.name  = "soc",
> +};
> +static bool soc_bus_registered;
> +
> +static void soc_device_add_params(struct soc_device *soc_dev)
> +{
> +	struct soc_device_attribute *attr = soc_dev->attr;
> +	struct device *dev = &soc_dev->dev;
> +
> +	if (attr->machine)
> +		dev_add_param_string_fixed(dev, "machine", attr->machine);
> +	if (attr->family)
> +		dev_add_param_string_fixed(dev, "family", attr->family);
> +	if (attr->revision)
> +		dev_add_param_string_fixed(dev, "revision", attr->revision);
> +	if (attr->serial_number)
> +		dev_add_param_string_fixed(dev, "serial_number", attr->serial_number);
> +	if (attr->soc_id)
> +		dev_add_param_string_fixed(dev, "soc_id", attr->soc_id);
> +}
> +
> +static void soc_device_get_machine(struct soc_device_attribute *soc_dev_attr)
> +{
> +	struct device_node *np;
> +
> +	if (soc_dev_attr->machine)
> +		return;
> +
> +	np = of_find_node_by_path("/");
> +	of_property_read_string(np, "model", &soc_dev_attr->machine);
> +	of_node_put(np);
> +}
> +
> +static struct soc_device_attribute *early_soc_dev_attr;
> +
> +struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr)
> +{
> +	struct soc_device *soc_dev;
> +	int ret;
> +
> +	soc_device_get_machine(soc_dev_attr);
> +
> +	if (!soc_bus_registered) {
> +		if (early_soc_dev_attr)
> +			return ERR_PTR(-EBUSY);
> +		early_soc_dev_attr = soc_dev_attr;
> +		return NULL;
> +	}
> +
> +	soc_dev = kzalloc(sizeof(*soc_dev), GFP_KERNEL);
> +	if (!soc_dev) {
> +		ret = -ENOMEM;
> +		goto out1;
> +	}
> +
> +	soc_dev->attr = soc_dev_attr;
> +	soc_dev->dev.bus = &soc_bus_type;
> +	soc_dev->dev.id = DEVICE_ID_DYNAMIC;
> +
> +	dev_set_name(&soc_dev->dev, "soc");
> +
> +	ret = device_register(&soc_dev->dev);
> +	if (ret) {
> +		put_device(&soc_dev->dev);
> +		goto out2;
> +	}
> +
> +	soc_device_add_params(soc_dev);
> +
> +	return soc_dev;
> +
> +out2:
> +	kfree(soc_dev);
> +out1:
> +	return ERR_PTR(ret);
> +}
> +EXPORT_SYMBOL_GPL(soc_device_register);
> +
> +/* Ensure soc_dev->attr is freed after calling soc_device_unregister. */
> +void soc_device_unregister(struct soc_device *soc_dev)
> +{
> +	device_unregister(&soc_dev->dev);
> +	kfree(soc_dev);
> +	early_soc_dev_attr = NULL;
> +}
> +EXPORT_SYMBOL_GPL(soc_device_unregister);
> +
> +static int __init soc_bus_register(void)
> +{
> +	int ret;
> +
> +	ret = bus_register(&soc_bus_type);
> +	if (ret)
> +		return ret;
> +	soc_bus_registered = true;
> +
> +	if (early_soc_dev_attr)
> +		return PTR_ERR(soc_device_register(early_soc_dev_attr));
> +
> +	return 0;
> +}
> +core_initcall(soc_bus_register);
> diff --git a/include/linux/sys_soc.h b/include/linux/sys_soc.h
> new file mode 100644
> index 000000000000..fd597ae54096
> --- /dev/null
> +++ b/include/linux/sys_soc.h
> @@ -0,0 +1,39 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) ST-Ericsson SA 2011
> + * Author: Lee Jones <lee.jones@linaro.org> for ST-Ericsson.
> + */
> +#ifndef __SOC_BUS_H
> +#define __SOC_BUS_H
> +
> +#include <linux/device.h>
> +
> +struct soc_device_attribute {
> +	const char *machine;
> +	const char *family;
> +	const char *revision;
> +	const char *serial_number;
> +	const char *soc_id;
> +	const void *data;
> +};
> +
> +/**
> + * soc_device_register - register SoC as a device
> + * @soc_plat_dev_attr: Attributes passed from platform to be attributed to a SoC
> + */
> +struct soc_device *soc_device_register(
> +	struct soc_device_attribute *soc_plat_dev_attr);
> +
> +/**
> + * soc_device_unregister - unregister SoC device
> + * @dev: SoC device to be unregistered
> + */
> +void soc_device_unregister(struct soc_device *soc_dev);
> +
> +/**
> + * soc_device_to_device - helper function to fetch struct device
> + * @soc: Previously registered SoC device container
> + */
> +struct device *soc_device_to_device(struct soc_device *soc);
> +
> +#endif /* __SOC_BUS_H */
> -- 
> 2.39.2
> 
> 
> 

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