Unverified Commit 7dbb4a38 authored by Jonathan Neuschäfer's avatar Jonathan Neuschäfer Committed by Arnd Bergmann
Browse files

soc: nuvoton: Add SoC info driver for WPCM450 



Add a SoC information driver for Nuvoton WPCM450 SoCs. It provides
information such as the SoC revision.

Usage example:

  # grep . /sys/devices/soc0/*
  /sys/devices/soc0/family:Nuvoton NPCM
  /sys/devices/soc0/revision:A3
  /sys/devices/soc0/soc_id:WPCM450

Signed-off-by: default avatarJonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-by: default avatarJoel Stanley <joel@jms.id.au>
Reviewed-by: default avatarPaul Menzel <pmenzel@molgen.mpg.de>
Link: https://lore.kernel.org/r/20221031223926.241641-1-j.neuschaefer@gmx.net


Signed-off-by: default avatarJoel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20230201051717.1005938-1-joel@jms.id.au


Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 0ad2185d

drivers/soc/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ source "drivers/soc/litex/Kconfig" 
source "drivers/soc/loongson/Kconfig"

source "drivers/soc/mediatek/Kconfig"

source "drivers/soc/microchip/Kconfig"

source "drivers/soc/nuvoton/Kconfig"

source "drivers/soc/pxa/Kconfig"

source "drivers/soc/qcom/Kconfig"

source "drivers/soc/renesas/Kconfig"

drivers/soc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ obj-$(CONFIG_LITEX_SOC_CONTROLLER) += litex/ 
obj-y				+= loongson/

obj-y				+= mediatek/

obj-y				+= microchip/

obj-y				+= nuvoton/

obj-y				+= pxa/

obj-y				+= amlogic/

obj-y				+= qcom/

drivers/soc/nuvoton/Kconfig

0 → 100644
+11 −0
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# SPDX-License-Identifier: GPL-2.0

menuconfig WPCM450_SOC

	tristate "Nuvoton WPCM450 SoC driver"

	default y if ARCH_WPCM450

	select SOC_BUS

	help

	  Say Y here to compile the SoC information driver for Nuvoton

	  WPCM450 SoCs.



	  This driver provides information such as the SoC model and

	  revision.

drivers/soc/nuvoton/Makefile

0 → 100644
+2 −0
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# SPDX-License-Identifier: GPL-2.0-only

obj-$(CONFIG_WPCM450_SOC)	+= wpcm450-soc.o

drivers/soc/nuvoton/wpcm450-soc.c

0 → 100644
+109 −0
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// SPDX-License-Identifier: GPL-2.0

/*

 * Nuvoton WPCM450 SoC Identification

 *

 * Copyright (C) 2022 Jonathan Neuschäfer

 */



#include <linux/mfd/syscon.h>

#include <linux/of.h>

#include <linux/regmap.h>

#include <linux/slab.h>

#include <linux/sys_soc.h>



#define GCR_PDID	0

#define PDID_CHIP(x)	((x) & 0x00ffffff)

#define CHIP_WPCM450	0x926450

#define PDID_REV(x)	((x) >> 24)



struct revision {

	u8 number;

	const char *name;

};



static const struct revision revisions[] __initconst = {

	{ 0x00, "Z1" },

	{ 0x03, "Z2" },

	{ 0x04, "Z21" },

	{ 0x08, "A1" },

	{ 0x09, "A2" },

	{ 0x0a, "A3" },

	{}

};



static const char * __init get_revision(unsigned int rev)

{

	int i;



	for (i = 0; revisions[i].name; i++)

		if (revisions[i].number == rev)

			return revisions[i].name;

	return NULL;

}



static struct soc_device_attribute *wpcm450_attr;

static struct soc_device *wpcm450_soc;



static int __init wpcm450_soc_init(void)

{

	struct soc_device_attribute *attr;

	struct soc_device *soc;

	const char *revision;

	struct regmap *gcr;

	u32 pdid;

	int ret;



	if (!of_machine_is_compatible("nuvoton,wpcm450"))

		return 0;



	gcr = syscon_regmap_lookup_by_compatible("nuvoton,wpcm450-gcr");

	if (IS_ERR(gcr))

		return PTR_ERR(gcr);

	ret = regmap_read(gcr, GCR_PDID, &pdid);

	if (ret)

		return ret;



	if (PDID_CHIP(pdid) != CHIP_WPCM450) {

		pr_warn("Unknown chip ID in GCR.PDID: 0x%06x\n", PDID_CHIP(pdid));

		return -ENODEV;

	}



	revision = get_revision(PDID_REV(pdid));

	if (!revision) {

		pr_warn("Unknown chip revision in GCR.PDID: 0x%02x\n", PDID_REV(pdid));

		return -ENODEV;

	}



	attr = kzalloc(sizeof(*attr), GFP_KERNEL);

	if (!attr)

		return -ENOMEM;



	attr->family = "Nuvoton NPCM";

	attr->soc_id = "WPCM450";

	attr->revision = revision;

	soc = soc_device_register(attr);

	if (IS_ERR(soc)) {

		kfree(attr);

		pr_warn("Could not register SoC device\n");

		return PTR_ERR(soc);

	}



	wpcm450_soc = soc;

	wpcm450_attr = attr;

	return 0;

}

module_init(wpcm450_soc_init);



static void __exit wpcm450_soc_exit(void)

{

	if (wpcm450_soc) {

		soc_device_unregister(wpcm450_soc);

		wpcm450_soc = NULL;

		kfree(wpcm450_attr);

	}

}

module_exit(wpcm450_soc_exit);



MODULE_LICENSE("GPL");

MODULE_AUTHOR("Jonathan Neuschäfer");

MODULE_DESCRIPTION("Nuvoton WPCM450 SoC Identification driver");