Binary sysfs skeleton taken over from drivers/pci/pci-sysfs.c /sys/devices/system/ec/*/io A userspace app to easily read/write the EC can be found here: ftp://ftp.suse.com/pub/people/trenn/sources/ec/ec_access.c Signed-off-by: Thomas Renninger <trenn@xxxxxxx> Index: linux-2.6.34-master/drivers/acpi/ec_sys.c =================================================================== --- Documentation/acpi/ec_sysfs | 33 +++++++++++++++ drivers/acpi/ec_sys.c | 95 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 128 insertions(+), 0 deletions(-) create mode 100644 Documentation/acpi/ec_sysfs diff --git a/Documentation/acpi/ec_sysfs b/Documentation/acpi/ec_sysfs new file mode 100644 index 0000000..479225b --- /dev/null +++ b/Documentation/acpi/ec_sysfs @@ -0,0 +1,33 @@ + EC Sysfs File Description + +This file descibes sysfs files under: +/sys/devices/system/ec + +Currently only one Embedded Controller is supported. +This could get extended easily if such an ACPI supporting +system exist, but until know there has no need be seen. + +/sys/devices/system/ec/ec0/gpe +An integer value showing the General Purpose Event the EC +serves and has its handler installed on. +A GPE is an ACPI interrupt (compare with /proc/interrupts) +with a specific value retrieved from a HW register associated +to it. If the value equals the EC GPE, this event is processed +by the EC. +The activity of the EC GPE can be monitored like that: +GPE=`cat /sys/devices/system/ec/ec0/gpe` +watch -n1 cat /sys/firmware/acpi/interrupts/gpe${GPE} + +/sys/devices/system/ec/ec0/use_global_lock +Shows whether BIOS requested the OS to use the global ACPI +lock on EC transitions (compare with ACPI specification for +details). + +/sys/devices/system/ec/ec0/io +Provides access to the 255 EC registers. +Its input and output is binary. +A userspace tool to easily read/write the EC can be found here: +ftp://ftp.suse.com/pub/people/trenn/sources/ec/ec_access.c +This file is for debugging purposes only. +!!! THE EC MUST ONLY GET ACCESSED THROUGH THE KERNEL, INTERPRETING +ACPI CODE ON PRODUCTIVE SYSTEMS !!! diff --git a/drivers/acpi/ec_sys.c b/drivers/acpi/ec_sys.c index c64236f..9793c57 100644 --- a/drivers/acpi/ec_sys.c +++ b/drivers/acpi/ec_sys.c @@ -1,3 +1,13 @@ +/* + * ec_sys.c + * + * Copyright (C) 2010 SUSE Products GmbH/Novell + * Author: + * Thomas Renninger <trenn@xxxxxxx> + * + * This work is licensed under the terms of the GNU GPL, version 2. + */ + #include <linux/kernel.h> #include <linux/sysdev.h> #include <linux/acpi.h> @@ -8,6 +18,8 @@ MODULE_AUTHOR("Thomas Renninger <trenn@xxxxxxx>"); MODULE_DESCRIPTION("ACPI EC sysfs access driver"); MODULE_LICENSE("GPL"); +#define EC_SPACE_SIZE 256 + struct sysdev_class acpi_ec_sysdev_class = { .name = "ec", }; @@ -32,6 +44,84 @@ static ssize_t show_ec_global_lock(struct sys_device *dev, SYSDEV_ATTR(gpe, 0444, show_ec_gpe, NULL); SYSDEV_ATTR(use_global_lock, 0444, show_ec_global_lock, NULL); + +/* TBD: ec_read/ec_write is only supported for one EC in a system + This needs adjustion in ec.c first +*/ +static ssize_t +acpi_ec_read_io(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + /* Use this if support reading/writing multiple ECs exists in ec.c: + struct sys_device *sysdev = container_of(kobj, struct sys_device, kobj); + struct acpi_ec *ec = container_of(sysdev, struct acpi_ec, sysdev); + */ + unsigned int size = EC_SPACE_SIZE; + u8 *data = (u8 *) buf; + loff_t init_off = off; + int err = 0; + + if (off >= size) + return 0; + if (off + count >= size) { + size -= off; + count = size; + } else + size = count; + + while (size) { + err = ec_read(off, &data[off - init_off]); + if (err) + return err; + off++; + size--; + } + return count; +} + +static ssize_t +acpi_ec_write_io(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + /* Use this if support reading/writing multiple ECs exists in ec.c: + struct sys_device *sysdev = container_of(kobj, struct sys_device, kobj); + struct acpi_ec *ec = container_of(sysdev, struct acpi_ec, sysdev); + */ + unsigned int size = count; + loff_t init_off = off; + u8 *data = (u8 *) buf; + int err = 0; + + if (off >= EC_SPACE_SIZE) + return 0; + if (off + count >= EC_SPACE_SIZE) { + size = EC_SPACE_SIZE - off; + count = size; + } + + while (size) { + u8 byte_write = data[off - init_off]; + err = ec_write(off, byte_write); + if (err) + return err; + off++; + size--; + } + return count; +} + +static struct bin_attribute acpi_ec_io_attr = { + .attr = { + .name = "io", + .mode = S_IRUGO | S_IWUSR, + }, + .size = EC_SPACE_SIZE, + .read = acpi_ec_read_io, + .write = acpi_ec_write_io, +}; + int acpi_ec_add_sysfs(struct acpi_ec *ec, int ec_device_count) { int err = 0; @@ -53,8 +143,13 @@ int acpi_ec_add_sysfs(struct acpi_ec *ec, int ec_device_count) err = sysdev_create_file(&ec->sysdev, &attr_gpe); if (err) goto file_err_2; + err = sysfs_create_bin_file(&ec->sysdev.kobj, &acpi_ec_io_attr); + if (err) + goto file_err_3; return err; + file_err_3: + sysdev_remove_file(&ec->sysdev, &attr_gpe); file_err_2: sysdev_remove_file(&ec->sysdev, &attr_use_global_lock); file_err_1: -- 1.6.3 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
