linux-hardened/drivers/base/soc.c

241 lines
5.8 KiB
C
Raw Normal View History

/*
* Copyright (C) ST-Ericsson SA 2011
*
* Author: Lee Jones <lee.jones@linaro.org> for ST-Ericsson.
* License terms: GNU General Public License (GPL), version 2
*/
#include <linux/sysfs.h>
#include <linux/init.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/idr.h>
#include <linux/spinlock.h>
#include <linux/sys_soc.h>
#include <linux/err.h>
base: soc: Introduce soc_device_match() interface We keep running into cases where device drivers want to know the exact version of the a SoC they are currently running on. In the past, this has usually been done through a vendor specific API that can be called by a driver, or by directly accessing some kind of version register that is not part of the device itself but that belongs to a global register area of the chip. Common reasons for doing this include: - A machine is not using devicetree or similar for passing data about on-chip devices, but just announces their presence using boot-time platform devices, and the machine code itself does not care about the revision. - There is existing firmware or boot loaders with existing DT binaries with generic compatible strings that do not identify the particular revision of each device, but the driver knows which SoC revisions include which part. - A prerelease version of a chip has some quirks and we are using the same version of the bootloader and the DT blob on both the prerelease and the final version. An update of the DT binding seems inappropriate because that would involve maintaining multiple copies of the dts and/or bootloader. This patch introduces the soc_device_match() interface that is meant to work like of_match_node() but instead of identifying the version of a device, it identifies the SoC itself using a vendor-agnostic interface. Unlike of_match_node(), we do not do an exact string compare but instead use glob_match() to allow wildcards in strings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 08:57:19 +02:00
#include <linux/glob.h>
static DEFINE_IDA(soc_ida);
static ssize_t soc_info_get(struct device *dev,
struct device_attribute *attr,
char *buf);
struct soc_device {
struct device dev;
struct soc_device_attribute *attr;
int soc_dev_num;
};
static struct bus_type soc_bus_type = {
.name = "soc",
};
static DEVICE_ATTR(machine, S_IRUGO, soc_info_get, NULL);
static DEVICE_ATTR(family, S_IRUGO, soc_info_get, NULL);
static DEVICE_ATTR(soc_id, S_IRUGO, soc_info_get, NULL);
static DEVICE_ATTR(revision, S_IRUGO, soc_info_get, NULL);
struct device *soc_device_to_device(struct soc_device *soc_dev)
{
return &soc_dev->dev;
}
static umode_t soc_attribute_mode(struct kobject *kobj,
struct attribute *attr,
int index)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
if ((attr == &dev_attr_machine.attr)
&& (soc_dev->attr->machine != NULL))
return attr->mode;
if ((attr == &dev_attr_family.attr)
&& (soc_dev->attr->family != NULL))
return attr->mode;
if ((attr == &dev_attr_revision.attr)
&& (soc_dev->attr->revision != NULL))
return attr->mode;
if ((attr == &dev_attr_soc_id.attr)
&& (soc_dev->attr->soc_id != NULL))
return attr->mode;
/* Unknown or unfilled attribute. */
return 0;
}
static ssize_t soc_info_get(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
if (attr == &dev_attr_machine)
return sprintf(buf, "%s\n", soc_dev->attr->machine);
if (attr == &dev_attr_family)
return sprintf(buf, "%s\n", soc_dev->attr->family);
if (attr == &dev_attr_revision)
return sprintf(buf, "%s\n", soc_dev->attr->revision);
if (attr == &dev_attr_soc_id)
return sprintf(buf, "%s\n", soc_dev->attr->soc_id);
return -EINVAL;
}
static struct attribute *soc_attr[] = {
&dev_attr_machine.attr,
&dev_attr_family.attr,
&dev_attr_soc_id.attr,
&dev_attr_revision.attr,
NULL,
};
static const struct attribute_group soc_attr_group = {
.attrs = soc_attr,
.is_visible = soc_attribute_mode,
};
static const struct attribute_group *soc_attr_groups[] = {
&soc_attr_group,
NULL,
};
static void soc_release(struct device *dev)
{
struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
kfree(soc_dev);
}
struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr)
{
struct soc_device *soc_dev;
int ret;
if (!soc_bus_type.p) {
ret = bus_register(&soc_bus_type);
if (ret)
goto out1;
}
soc_dev = kzalloc(sizeof(*soc_dev), GFP_KERNEL);
if (!soc_dev) {
ret = -ENOMEM;
goto out1;
}
/* Fetch a unique (reclaimable) SOC ID. */
ret = ida_simple_get(&soc_ida, 0, 0, GFP_KERNEL);
if (ret < 0)
goto out2;
soc_dev->soc_dev_num = ret;
soc_dev->attr = soc_dev_attr;
soc_dev->dev.bus = &soc_bus_type;
soc_dev->dev.groups = soc_attr_groups;
soc_dev->dev.release = soc_release;
dev_set_name(&soc_dev->dev, "soc%d", soc_dev->soc_dev_num);
ret = device_register(&soc_dev->dev);
if (ret)
goto out3;
return soc_dev;
out3:
ida_simple_remove(&soc_ida, soc_dev->soc_dev_num);
out2:
kfree(soc_dev);
out1:
return ERR_PTR(ret);
}
/* Ensure soc_dev->attr is freed prior to calling soc_device_unregister. */
void soc_device_unregister(struct soc_device *soc_dev)
{
ida_simple_remove(&soc_ida, soc_dev->soc_dev_num);
device_unregister(&soc_dev->dev);
}
static int __init soc_bus_register(void)
{
if (soc_bus_type.p)
return 0;
return bus_register(&soc_bus_type);
}
core_initcall(soc_bus_register);
base: soc: Introduce soc_device_match() interface We keep running into cases where device drivers want to know the exact version of the a SoC they are currently running on. In the past, this has usually been done through a vendor specific API that can be called by a driver, or by directly accessing some kind of version register that is not part of the device itself but that belongs to a global register area of the chip. Common reasons for doing this include: - A machine is not using devicetree or similar for passing data about on-chip devices, but just announces their presence using boot-time platform devices, and the machine code itself does not care about the revision. - There is existing firmware or boot loaders with existing DT binaries with generic compatible strings that do not identify the particular revision of each device, but the driver knows which SoC revisions include which part. - A prerelease version of a chip has some quirks and we are using the same version of the bootloader and the DT blob on both the prerelease and the final version. An update of the DT binding seems inappropriate because that would involve maintaining multiple copies of the dts and/or bootloader. This patch introduces the soc_device_match() interface that is meant to work like of_match_node() but instead of identifying the version of a device, it identifies the SoC itself using a vendor-agnostic interface. Unlike of_match_node(), we do not do an exact string compare but instead use glob_match() to allow wildcards in strings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 08:57:19 +02:00
static int soc_device_match_one(struct device *dev, void *arg)
{
struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
const struct soc_device_attribute *match = arg;
if (match->machine &&
(!soc_dev->attr->machine ||
!glob_match(match->machine, soc_dev->attr->machine)))
base: soc: Introduce soc_device_match() interface We keep running into cases where device drivers want to know the exact version of the a SoC they are currently running on. In the past, this has usually been done through a vendor specific API that can be called by a driver, or by directly accessing some kind of version register that is not part of the device itself but that belongs to a global register area of the chip. Common reasons for doing this include: - A machine is not using devicetree or similar for passing data about on-chip devices, but just announces their presence using boot-time platform devices, and the machine code itself does not care about the revision. - There is existing firmware or boot loaders with existing DT binaries with generic compatible strings that do not identify the particular revision of each device, but the driver knows which SoC revisions include which part. - A prerelease version of a chip has some quirks and we are using the same version of the bootloader and the DT blob on both the prerelease and the final version. An update of the DT binding seems inappropriate because that would involve maintaining multiple copies of the dts and/or bootloader. This patch introduces the soc_device_match() interface that is meant to work like of_match_node() but instead of identifying the version of a device, it identifies the SoC itself using a vendor-agnostic interface. Unlike of_match_node(), we do not do an exact string compare but instead use glob_match() to allow wildcards in strings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 08:57:19 +02:00
return 0;
if (match->family &&
(!soc_dev->attr->family ||
!glob_match(match->family, soc_dev->attr->family)))
base: soc: Introduce soc_device_match() interface We keep running into cases where device drivers want to know the exact version of the a SoC they are currently running on. In the past, this has usually been done through a vendor specific API that can be called by a driver, or by directly accessing some kind of version register that is not part of the device itself but that belongs to a global register area of the chip. Common reasons for doing this include: - A machine is not using devicetree or similar for passing data about on-chip devices, but just announces their presence using boot-time platform devices, and the machine code itself does not care about the revision. - There is existing firmware or boot loaders with existing DT binaries with generic compatible strings that do not identify the particular revision of each device, but the driver knows which SoC revisions include which part. - A prerelease version of a chip has some quirks and we are using the same version of the bootloader and the DT blob on both the prerelease and the final version. An update of the DT binding seems inappropriate because that would involve maintaining multiple copies of the dts and/or bootloader. This patch introduces the soc_device_match() interface that is meant to work like of_match_node() but instead of identifying the version of a device, it identifies the SoC itself using a vendor-agnostic interface. Unlike of_match_node(), we do not do an exact string compare but instead use glob_match() to allow wildcards in strings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 08:57:19 +02:00
return 0;
if (match->revision &&
(!soc_dev->attr->revision ||
!glob_match(match->revision, soc_dev->attr->revision)))
base: soc: Introduce soc_device_match() interface We keep running into cases where device drivers want to know the exact version of the a SoC they are currently running on. In the past, this has usually been done through a vendor specific API that can be called by a driver, or by directly accessing some kind of version register that is not part of the device itself but that belongs to a global register area of the chip. Common reasons for doing this include: - A machine is not using devicetree or similar for passing data about on-chip devices, but just announces their presence using boot-time platform devices, and the machine code itself does not care about the revision. - There is existing firmware or boot loaders with existing DT binaries with generic compatible strings that do not identify the particular revision of each device, but the driver knows which SoC revisions include which part. - A prerelease version of a chip has some quirks and we are using the same version of the bootloader and the DT blob on both the prerelease and the final version. An update of the DT binding seems inappropriate because that would involve maintaining multiple copies of the dts and/or bootloader. This patch introduces the soc_device_match() interface that is meant to work like of_match_node() but instead of identifying the version of a device, it identifies the SoC itself using a vendor-agnostic interface. Unlike of_match_node(), we do not do an exact string compare but instead use glob_match() to allow wildcards in strings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 08:57:19 +02:00
return 0;
if (match->soc_id &&
(!soc_dev->attr->soc_id ||
!glob_match(match->soc_id, soc_dev->attr->soc_id)))
base: soc: Introduce soc_device_match() interface We keep running into cases where device drivers want to know the exact version of the a SoC they are currently running on. In the past, this has usually been done through a vendor specific API that can be called by a driver, or by directly accessing some kind of version register that is not part of the device itself but that belongs to a global register area of the chip. Common reasons for doing this include: - A machine is not using devicetree or similar for passing data about on-chip devices, but just announces their presence using boot-time platform devices, and the machine code itself does not care about the revision. - There is existing firmware or boot loaders with existing DT binaries with generic compatible strings that do not identify the particular revision of each device, but the driver knows which SoC revisions include which part. - A prerelease version of a chip has some quirks and we are using the same version of the bootloader and the DT blob on both the prerelease and the final version. An update of the DT binding seems inappropriate because that would involve maintaining multiple copies of the dts and/or bootloader. This patch introduces the soc_device_match() interface that is meant to work like of_match_node() but instead of identifying the version of a device, it identifies the SoC itself using a vendor-agnostic interface. Unlike of_match_node(), we do not do an exact string compare but instead use glob_match() to allow wildcards in strings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 08:57:19 +02:00
return 0;
return 1;
}
/*
* soc_device_match - identify the SoC in the machine
* @matches: zero-terminated array of possible matches
*
* returns the first matching entry of the argument array, or NULL
* if none of them match.
*
* This function is meant as a helper in place of of_match_node()
* in cases where either no device tree is available or the information
* in a device node is insufficient to identify a particular variant
* by its compatible strings or other properties. For new devices,
* the DT binding should always provide unique compatible strings
* that allow the use of of_match_node() instead.
*
* The calling function can use the .data entry of the
* soc_device_attribute to pass a structure or function pointer for
* each entry.
*/
const struct soc_device_attribute *soc_device_match(
const struct soc_device_attribute *matches)
{
int ret = 0;
if (!matches)
return NULL;
while (!ret) {
if (!(matches->machine || matches->family ||
matches->revision || matches->soc_id))
break;
ret = bus_for_each_dev(&soc_bus_type, NULL, (void *)matches,
soc_device_match_one);
if (!ret)
matches++;
else
return matches;
}
return NULL;
}
EXPORT_SYMBOL_GPL(soc_device_match);