linux/arch/arm/mach-at91/soc.c

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/*
* 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;
}