linux/arch/arm/mach-at91/soc.c
Ludovic Desroches 2f26e6189d ARM: at91: use chipid device for soc detection
So far, the CIDR and EXID registers were in the DBGU interface. This device
has disappeared with the SAMA5D2 family. These registers are exposed
through a new device called chipid.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
[nicolas.ferre@atmel.com: remove useless warnings]
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
[arnd@arndb.de: suggest to use static functions to reduce scope]
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2016-03-29 16:34:21 +02:00

143 lines
3.2 KiB
C

/*
* Copyright (C) 2015 Atmel
*
* Alexandre Belloni <alexandre.belloni@free-electrons.com
* Boris Brezillon <boris.brezillon@free-electrons.com
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*
*/
#define pr_fmt(fmt) "AT91: " fmt
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
#include <linux/sys_soc.h>
#include "soc.h"
#define AT91_DBGU_CIDR 0x40
#define AT91_DBGU_EXID 0x44
#define AT91_CHIPID_CIDR 0x00
#define AT91_CHIPID_EXID 0x04
#define AT91_CIDR_VERSION(x) ((x) & 0x1f)
#define AT91_CIDR_EXT BIT(31)
#define AT91_CIDR_MATCH_MASK 0x7fffffe0
static int __init at91_get_cidr_exid_from_dbgu(u32 *cidr, u32 *exid)
{
struct device_node *np;
void __iomem *regs;
np = of_find_compatible_node(NULL, NULL, "atmel,at91rm9200-dbgu");
if (!np)
np = of_find_compatible_node(NULL, NULL,
"atmel,at91sam9260-dbgu");
if (!np)
return -ENODEV;
regs = of_iomap(np, 0);
of_node_put(np);
if (!regs) {
pr_warn("Could not map DBGU iomem range");
return -ENXIO;
}
*cidr = readl(regs + AT91_DBGU_CIDR);
*exid = readl(regs + AT91_DBGU_EXID);
iounmap(regs);
return 0;
}
static int __init at91_get_cidr_exid_from_chipid(u32 *cidr, u32 *exid)
{
struct device_node *np;
void __iomem *regs;
np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-chipid");
if (!np)
return -ENODEV;
regs = of_iomap(np, 0);
of_node_put(np);
if (!regs) {
pr_warn("Could not map DBGU iomem range");
return -ENXIO;
}
*cidr = readl(regs + AT91_CHIPID_CIDR);
*exid = readl(regs + AT91_CHIPID_EXID);
iounmap(regs);
return 0;
}
struct soc_device * __init at91_soc_init(const struct at91_soc *socs)
{
struct soc_device_attribute *soc_dev_attr;
const struct at91_soc *soc;
struct soc_device *soc_dev;
u32 cidr, exid;
int ret;
/*
* With SAMA5D2 and later SoCs, CIDR and EXID registers are no more
* in the dbgu device but in the chipid device whose purpose is only
* to expose these two registers.
*/
ret = at91_get_cidr_exid_from_dbgu(&cidr, &exid);
if (ret)
ret = at91_get_cidr_exid_from_chipid(&cidr, &exid);
if (ret) {
if (ret == -ENODEV)
pr_warn("Could not find identification node");
return NULL;
}
for (soc = socs; soc->name; soc++) {
if (soc->cidr_match != (cidr & AT91_CIDR_MATCH_MASK))
continue;
if (!(cidr & AT91_CIDR_EXT) || soc->exid_match == exid)
break;
}
if (!soc->name) {
pr_warn("Could not find matching SoC description\n");
return NULL;
}
soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
if (!soc_dev_attr)
return NULL;
soc_dev_attr->family = soc->family;
soc_dev_attr->soc_id = soc->name;
soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%X",
AT91_CIDR_VERSION(cidr));
soc_dev = soc_device_register(soc_dev_attr);
if (IS_ERR(soc_dev)) {
kfree(soc_dev_attr->revision);
kfree(soc_dev_attr);
pr_warn("Could not register SoC device\n");
return NULL;
}
if (soc->family)
pr_info("Detected SoC family: %s\n", soc->family);
pr_info("Detected SoC: %s, revision %X\n", soc->name,
AT91_CIDR_VERSION(cidr));
return soc_dev;
}