linux/drivers/soc/nuvoton/wpcm450-soc.c
Jonathan Neuschäfer 7dbb4a38bf
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: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Link: https://lore.kernel.org/r/20221031223926.241641-1-j.neuschaefer@gmx.net
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20230201051717.1005938-1-joel@jms.id.au
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2023-02-01 17:11:36 +01:00

110 lines
2.2 KiB
C

// 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");