Here is the second version of the proposal to export SoC related information to user-space through sysFS interface.
The first patch introduces the common part, which provides an interface to the platform to export platform-defined IDs to user-space.
The IDs strings can be provided in two ways: either with a pointer to the string, or by a callback fullfilling the sysfs's "show" callback buffer.
The second patch is given as example for the ux500 architecture. It registers the socinfo interface, and exports 5 values (Family name, machine name, silicon process, silicon revision, and serial number).
Here is the output for DB8500:
root@ME:/sys/socinfo ls -l
-r--r--r-- 1 root root 4096 Jan 2 03:35 family
-r--r--r-- 1 root root 4096 Jan 2 03:35 machine
-r--r--r-- 1 root root 4096 Jan 2 03:35 process
-r--r--r-- 1 root root 4096 Jan 2 03:35 revision
-r--r--r-- 1 root root 4096 Jan 2 03:35 soc_id
root@ME:/sys/socinfo cat machine
DB8500
root@ME:/sys/socinfo cat family
Ux500
root@ME:/sys/socinfo cat process
Standard
root@ME:/sys/socinfo cat revision
2.0
root@ME:/sys/socinfo cat soc_id
2ba07ce9e5835d6185321e9577462ef2ea2129cf
-------------------------------------------------------------------------------
v1:
Conclusion about first version :
* /sys/devices/system is not right place for this interface.
* "mach_name" should be declared as other attributes to simplify code.
* The get_info callback should use directly the "show" callback buffer.
* Documentation was missing (ABI description required)
* Errors were not reported at registration time.
* Macros should be used to create attributes.
* Some kernel coding rules not followed.
-------------------------------------------------------------------------------
Any comments are welcome.
Note that I will be off from 13th to 21th of March.
Regards,
Maxime
-------------------------------------------------------------------------------
Maxime Coquelin (2):
Export SoC info through sysfs
ux500: Export U8500 SoC info through sysfs
Documentation/ABI/testing/sysfs-socinfo | 16 ++++++
arch/arm/mach-ux500/Kconfig | 1 +
arch/arm/mach-ux500/id.c | 70 +++++++++++++++++++++++++++
drivers/base/Kconfig | 3 +
drivers/base/Makefile | 1 +
drivers/base/soc.c | 79 +++++++++++++++++++++++++++++++
include/linux/sys_soc.h | 50 +++++++++++++++++++
7 files changed, 220 insertions(+), 0 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-socinfo
create mode 100644 drivers/base/soc.c
create mode 100644 include/linux/sys_soc.h
Common base to export System-on-Chip related informations through sysfs.
Creation of a "socinfo" directory under /sys/.
Creation of SoC information entries.
Signed-off-by: Maxime COQUELIN <[email protected]>
---
Documentation/ABI/testing/sysfs-socinfo | 16 ++++++
drivers/base/Kconfig | 3 +
drivers/base/Makefile | 1 +
drivers/base/soc.c | 79 +++++++++++++++++++++++++++++++
include/linux/sys_soc.h | 50 +++++++++++++++++++
5 files changed, 149 insertions(+), 0 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-socinfo
create mode 100644 drivers/base/soc.c
create mode 100644 include/linux/sys_soc.h
diff --git a/Documentation/ABI/testing/sysfs-socinfo b/Documentation/ABI/testing/sysfs-socinfo
new file mode 100644
index 0000000..afd9da2
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-socinfo
@@ -0,0 +1,16 @@
+What: /sys/socinfo
+Date: March 2011
+contact: Maxime Coquelin <[email protected]>
+Description:
+ The /sys/socinfo directory contains information about the
+ System-on-Chip. It is only available if platform implements it.
+ This directory contains two kind of attributes :
+ - common attributes:
+ * machine: the name of the machine.
+ * family: the family name of the SoC
+ - SoC-specific attributes: The SoC vendor can declare attributes
+ to export some strings to user-space, like the serial-number for
+ example.
+
+Users:
+ User-space applications which needs these kind of attributes.
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index d57e8d0..372ef3a 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -168,4 +168,7 @@ config SYS_HYPERVISOR
bool
default n
+config SYS_SOC
+ bool
+
endmenu
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index 5f51c3b..f3bcfb3 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -18,6 +18,7 @@ ifeq ($(CONFIG_SYSFS),y)
obj-$(CONFIG_MODULES) += module.o
endif
obj-$(CONFIG_SYS_HYPERVISOR) += hypervisor.o
+obj-$(CONFIG_SYS_SOC) += soc.o
ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
diff --git a/drivers/base/soc.c b/drivers/base/soc.c
new file mode 100644
index 0000000..046b43b
--- /dev/null
+++ b/drivers/base/soc.c
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2011
+ * Author: Maxime Coquelin <[email protected]> for ST-Ericsson.
+ * License terms: GNU General Public License (GPL), version 2
+ */
+
+#include <linux/sysfs.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/stat.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+
+struct kobject *soc_object;
+
+ssize_t show_soc_info(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct sysfs_soc_info *si = container_of(attr,
+ struct sysfs_soc_info, attr);
+
+ if (si->info)
+ return sprintf(buf, "%s\n", si->info);
+
+ return si->get_info(buf, si);
+}
+
+int __init register_sysfs_soc_info(struct sysfs_soc_info *info, int nb_info)
+{
+ int i, ret;
+
+ for (i = 0; i < nb_info; i++) {
+ ret = sysfs_create_file(soc_object, &info[i].attr.attr);
+ if (ret) {
+ for (i -= 1; i >= 0; i--)
+ sysfs_remove_file(soc_object, &info[i].attr.attr);
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static struct attribute *soc_attrs[] = {
+ NULL,
+};
+
+static struct attribute_group soc_attr_group = {
+ .attrs = soc_attrs,
+};
+
+int __init register_sysfs_soc(struct sysfs_soc_info *info, size_t num)
+{
+ int ret;
+
+ soc_object = kobject_create_and_add("socinfo", NULL);
+ if (!soc_object) {
+ ret = -ENOMEM;
+ goto exit;
+ }
+
+ ret = sysfs_create_group(soc_object, &soc_attr_group);
+ if (ret)
+ goto kset_exit;
+
+ ret = register_sysfs_soc_info(info, num);
+ if (ret)
+ goto group_exit;
+
+ return 0;
+
+group_exit:
+ sysfs_remove_group(soc_object, &soc_attr_group);
+kset_exit:
+ kobject_put(soc_object);
+exit:
+ return ret;
+}
+
diff --git a/include/linux/sys_soc.h b/include/linux/sys_soc.h
new file mode 100644
index 0000000..05e5529
--- /dev/null
+++ b/include/linux/sys_soc.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2011
+ * Author: Maxime Coquelin <[email protected]> for ST-Ericsson.
+ * License terms: GNU General Public License (GPL), version 2
+ */
+#ifndef __SYS_SOC_H
+#define __SYS_SOC_H
+
+#include <linux/kobject.h>
+
+/**
+ * struct sys_soc_info - SoC exports related informations
+ * @name: name of the export
+ * @info: pointer on the key to export
+ * @get_info: callback to retrieve key if info field is NULL
+ * @attr: export's sysdev class attribute
+ */
+struct sysfs_soc_info {
+ const char *info;
+ ssize_t (*get_info)(char *buf, struct sysfs_soc_info *);
+ struct kobj_attribute attr;
+};
+
+ssize_t show_soc_info(struct kobject *, struct kobj_attribute *, char *);
+
+#define SYSFS_SOC_ATTR_VALUE(_name, _value) { \
+ .attr.attr.name = _name, \
+ .attr.attr.mode = S_IRUGO, \
+ .attr.show = show_soc_info, \
+ .info = _value, \
+}
+
+#define SYSFS_SOC_ATTR_CALLBACK(_name, _callback) { \
+ .attr.attr.name = _name, \
+ .attr.attr.mode = S_IRUGO, \
+ .attr.show = show_soc_info, \
+ .get_info = _callback, \
+}
+
+/**
+ * register_sys_soc - register the soc information
+ * @name: name of the machine
+ * @info: pointer on the info table to export
+ * @num: number of info to export
+ *
+ * NOTE: This function must only be called once
+ */
+int register_sysfs_soc(struct sysfs_soc_info *info, size_t num);
+
+#endif /* __SYS_SOC_H */
--
1.7.1
ST-Ericsson's U8500 implementation.
Register sysfs SoC interface, and exports:
- Machine name
- Family name
- SoC ID
- Silicon process
- Silicon revision number.
Signed-off-by: Maxime COQUELIN <[email protected]>
socinfo : ux500 part 2
---
arch/arm/mach-ux500/Kconfig | 1 +
arch/arm/mach-ux500/id.c | 70 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 71 insertions(+), 0 deletions(-)
diff --git a/arch/arm/mach-ux500/Kconfig b/arch/arm/mach-ux500/Kconfig
index 7f8620f..08f9859 100644
--- a/arch/arm/mach-ux500/Kconfig
+++ b/arch/arm/mach-ux500/Kconfig
@@ -23,6 +23,7 @@ config MACH_U8500
bool "U8500 Development platform"
depends on UX500_SOC_DB8500
select TPS6105X
+ select SYS_SOC
help
Include support for the mop500 development platform.
diff --git a/arch/arm/mach-ux500/id.c b/arch/arm/mach-ux500/id.c
index d35122e..457b48e 100644
--- a/arch/arm/mach-ux500/id.c
+++ b/arch/arm/mach-ux500/id.c
@@ -8,6 +8,9 @@
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
+#include <linux/sys_soc.h>
+#include <linux/slab.h>
+#include <linux/stat.h>
#include <asm/cputype.h>
#include <asm/tlbflush.h>
@@ -105,3 +108,70 @@ void __init ux500_map_io(void)
ux500_print_soc_info(asicid);
}
+
+
+#ifdef CONFIG_SYS_SOC
+#define U8500_BB_UID_BASE (U8500_BACKUPRAM1_BASE + 0xFC0)
+#define U8500_BB_UID_LENGTH 5
+
+static ssize_t ux500_get_machine(char *buf, struct sysfs_soc_info *si)
+{
+ return sprintf(buf, "DB%4x\n", dbx500_partnumber());
+}
+
+static ssize_t ux500_get_soc_id(char *buf, struct sysfs_soc_info *si)
+{
+ void __iomem *uid_base;
+ int i;
+ ssize_t sz = 0;
+
+ if (dbx500_partnumber() == 0x8500) {
+ uid_base = __io_address(U8500_BB_UID_BASE);
+ for (i = 0; i < U8500_BB_UID_LENGTH; i++)
+ sz += sprintf(buf + sz, "%08x", readl(uid_base + i * sizeof(u32)));
+ sz += sprintf(buf + sz, "\n");
+ }
+ else {
+ /* Don't know where it is located for U5500 */
+ sz = sprintf(buf, "N/A\n");
+ }
+
+ return sz;
+}
+
+static ssize_t ux500_get_revision(char *buf, struct sysfs_soc_info *si)
+{
+ unsigned int rev = dbx500_revision();
+
+ if (rev == 0x01)
+ return sprintf(buf, "%s\n", "ED");
+ else if (rev >= 0xA0)
+ return sprintf(buf, "%d.%d\n" , (rev >> 4) - 0xA + 1, rev & 0xf);
+
+ return sprintf(buf, "%s", "Unknown\n");
+}
+
+static ssize_t ux500_get_process(char *buf, struct sysfs_soc_info *si)
+{
+ if (dbx500_id.process == 0x00)
+ return sprintf(buf, "Standard\n");
+
+ return sprintf(buf, "%02xnm\n", dbx500_id.process);
+}
+
+static struct sysfs_soc_info soc_info[] = {
+ SYSFS_SOC_ATTR_CALLBACK("machine", ux500_get_machine),
+ SYSFS_SOC_ATTR_VALUE("family", "Ux500"),
+ SYSFS_SOC_ATTR_CALLBACK("soc_id", ux500_get_soc_id),
+ SYSFS_SOC_ATTR_CALLBACK("revision", ux500_get_revision),
+ SYSFS_SOC_ATTR_CALLBACK("process", ux500_get_process),
+};
+
+static int __init ux500_sys_soc_init(void)
+{
+ return register_sysfs_soc(soc_info, ARRAY_SIZE(soc_info));
+}
+
+module_init(ux500_sys_soc_init);
+#endif
+
--
1.7.1