[PATCH 1/7] ACPI: Provide /sys/kernel/debug/ec/...

From: Thomas Renninger
Date: Fri Jul 16 2010 - 07:13:26 EST


This patch provides the same information through debugfs, which previously was
provided through /proc/acpi/embedded_controller/*/info

This is the gpe the EC is connected to and whether the global lock
gets used.
The io ports used are added to /proc/ioports in another patch.
Beside the fact that /proc/acpi is deprecated for quite some time,
this info is not needed for applications and thus can be moved
to debugfs instead of a public interface like /sys.

Signed-off-by: Thomas Renninger <trenn@xxxxxxx>

CC: Alexey Starikovskiy <astarikovskiy@xxxxxxx>
CC: Len Brown <lenb@xxxxxxxxxx>
CC: linux-kernel@xxxxxxxxxxxxxxx
CC: linux-acpi@xxxxxxxxxxxxxxx
CC: Bjorn Helgaas <bjorn.helgaas@xxxxxx>
CC: platform-driver-x86@xxxxxxxxxxxxxxx
---
drivers/acpi/Kconfig | 13 ++++++++++
drivers/acpi/Makefile | 1 +
drivers/acpi/ec.c | 18 ++++----------
drivers/acpi/ec_sys.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/acpi/internal.h | 24 +++++++++++++++++++
5 files changed, 100 insertions(+), 13 deletions(-)
create mode 100644 drivers/acpi/ec_sys.c

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 7464115..f7226d1 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -104,6 +104,19 @@ config ACPI_SYSFS_POWER
help
Say N to disable power /sys interface

+config ACPI_EC_DEBUGFS
+ tristate "EC read/write access through /sys/kernel/debug/ec"
+ default y
+ help
+ Say N to disable Embedded Controller /sys/kernel/debug interface
+
+ An Embedded Controller typically is available on laptops and reads
+ sensor values like battery state and temperature.
+ The kernel access the EC through ACPI parsed code provided by BIOS
+ tables.
+ Thus this option is a debug option that helps to write ACPI drivers
+ and can be used to identify ACPI code or EC firmware bugs.
+
config ACPI_PROC_EVENT
bool "Deprecated /proc/acpi/event support"
depends on PROC_FS
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 6ee3316..833b582 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -60,6 +60,7 @@ obj-$(CONFIG_ACPI_SBS) += sbshc.o
obj-$(CONFIG_ACPI_SBS) += sbs.o
obj-$(CONFIG_ACPI_POWER_METER) += power_meter.o
obj-$(CONFIG_ACPI_HED) += hed.o
+obj-$(CONFIG_ACPI_EC_DEBUGFS) += ec_sys.o

# processor has its own "processor." module_param namespace
processor-y := processor_driver.o processor_throttling.o
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 1e6d418..4b6759f 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -45,10 +45,13 @@
#include <acpi/acpi_drivers.h>
#include <linux/dmi.h>

+#include "internal.h"
+
#define ACPI_EC_CLASS "embedded_controller"
#define ACPI_EC_DEVICE_NAME "Embedded Controller"
#define ACPI_EC_FILE_INFO "info"

+#undef PREFIX
#define PREFIX "ACPI: EC: "

/* EC status register */
@@ -106,19 +109,8 @@ struct transaction {
bool done;
};

-static struct acpi_ec {
- acpi_handle handle;
- unsigned long gpe;
- unsigned long command_addr;
- unsigned long data_addr;
- unsigned long global_lock;
- unsigned long flags;
- struct mutex lock;
- wait_queue_head_t wait;
- struct list_head list;
- struct transaction *curr;
- spinlock_t curr_lock;
-} *boot_ec, *first_ec;
+struct acpi_ec *boot_ec, *first_ec;
+EXPORT_SYMBOL(first_ec);

static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
diff --git a/drivers/acpi/ec_sys.c b/drivers/acpi/ec_sys.c
new file mode 100644
index 0000000..834c21a
--- /dev/null
+++ b/drivers/acpi/ec_sys.c
@@ -0,0 +1,57 @@
+#include <linux/kernel.h>
+#include <linux/acpi.h>
+#include <linux/debugfs.h>
+#include "internal.h"
+
+MODULE_AUTHOR("Thomas Renninger <trenn@xxxxxxx>");
+MODULE_DESCRIPTION("ACPI EC sysfs access driver");
+MODULE_LICENSE("GPL");
+
+struct sysdev_class acpi_ec_sysdev_class = {
+ .name = "ec",
+};
+
+static struct dentry *acpi_ec_debugfs_dir;
+
+int acpi_ec_add_debugfs(struct acpi_ec *ec, unsigned int ec_device_count)
+{
+ struct dentry *dev_dir;
+ char name[64];
+ if (ec_device_count == 0) {
+ acpi_ec_debugfs_dir = debugfs_create_dir("ec", NULL);
+ if (!acpi_ec_debugfs_dir)
+ return -ENOMEM;
+ }
+
+ sprintf(name, "ec%u", ec_device_count);
+ dev_dir = debugfs_create_dir(name, acpi_ec_debugfs_dir);
+ if (!dev_dir) {
+ if (ec_device_count == 0)
+ debugfs_remove_recursive(acpi_ec_debugfs_dir);
+ /* TBD: Proper cleanup for multiple ECs */
+ return -ENOMEM;
+ }
+
+ debugfs_create_x32("gpe", 0444, dev_dir, (u32 *)&first_ec->gpe);
+ debugfs_create_bool("use_global_lock", 0444, dev_dir,
+ (u32 *)&first_ec->global_lock);
+ return 0;
+}
+
+static int __init acpi_ec_sys_init(void)
+{
+ int err = 0;
+ if (first_ec)
+ err = acpi_ec_add_debugfs(first_ec, 0);
+ else
+ err = -ENODEV;
+ return err;
+}
+
+static void __exit acpi_ec_sys_exit(void)
+{
+ debugfs_remove_recursive(acpi_ec_debugfs_dir);
+}
+
+module_init(acpi_ec_sys_init);
+module_exit(acpi_ec_sys_exit);
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index f8f190e..8ae2726 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -18,6 +18,11 @@
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*/

+#ifndef _ACPI_INTERNAL_H_
+#define _ACPI_INTERNAL_H_
+
+#include <linux/sysdev.h>
+
#define PREFIX "ACPI: "

int init_acpi_device_notify(void);
@@ -46,6 +51,23 @@ void acpi_early_processor_set_pdc(void);
/* --------------------------------------------------------------------------
Embedded Controller
-------------------------------------------------------------------------- */
+struct acpi_ec {
+ acpi_handle handle;
+ unsigned long gpe;
+ unsigned long command_addr;
+ unsigned long data_addr;
+ unsigned long global_lock;
+ unsigned long flags;
+ struct mutex lock;
+ wait_queue_head_t wait;
+ struct list_head list;
+ struct transaction *curr;
+ spinlock_t curr_lock;
+ struct sys_device sysdev;
+};
+
+extern struct acpi_ec *first_ec;
+
int acpi_ec_init(void);
int acpi_ec_ecdt_probe(void);
int acpi_boot_ec_enable(void);
@@ -63,3 +85,5 @@ int acpi_sleep_proc_init(void);
#else
static inline int acpi_sleep_proc_init(void) { return 0; }
#endif
+
+#endif /* _ACPI_INTERNAL_H_ */
--
1.6.3

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