3 files changed, 133 insertions, 2 deletions

diff --git a/Documentation/thinkpad-acpi.txt b/Documentation/thinkpad-acpi.txt
index 0e4e053cface..cc079afaf66b 100644
--- a/Documentation/thinkpad-acpi.txt
+++ b/Documentation/thinkpad-acpi.txt
@@ -101,11 +101,39 @@ follow all sysfs guidelines and correctly process all errors (the sysfs
 interface makes extensive use of errors).  File descriptors and open /
 close operations to the sysfs inodes must also be properly implemented.
 
-Driver version -- /proc/acpi/ibm/driver
----------------------------------------
+The version of thinkpad-acpi's sysfs interface is exported by the driver
+as a driver attribute (see below).
+
+Sysfs driver attributes are on the driver's sysfs attribute space,
+for 2.6.20 this is /sys/bus/platform/drivers/thinkpad-acpi/.
+
+Sysfs device attributes are on the driver's sysfs attribute space,
+for 2.6.20 this is /sys/devices/platform/thinkpad-acpi/.
+
+Driver version
+--------------
+
+procfs: /proc/acpi/ibm/driver
+sysfs driver attribute: version
 
 The driver name and version. No commands can be written to this file.
 
+Sysfs interface version
+-----------------------
+
+sysfs driver attribute: interface_version
+
+Version of the thinkpad-acpi sysfs interface, as an unsigned long
+(output in hex format: 0xAAAABBCC), where:
+        AAAA - major revision
+        BB - minor revision
+        CC - bugfix revision
+
+The sysfs interface version changelog for the driver can be found at the
+end of this document.  Changes to the sysfs interface done by the kernel
+subsystems are not documented here, nor are they tracked by this
+attribute.
+
 Hot keys -- /proc/acpi/ibm/hotkey
 ---------------------------------
 
@@ -745,9 +773,19 @@ to enable more than one output class, just add their values.
 There is also a kernel build option to enable more debugging
 information, which may be necessary to debug driver problems.
 
+The level of debugging information output by the driver can be changed
+at runtime through sysfs, using the driver attribute debug_level.  The
+attribute takes the same bitmask as the debug module parameter above.
+
 Force loading of module
 -----------------------
 
 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
 the module parameter force_load=1.  Regardless of whether this works or
 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
+
+
+Sysfs interface changelog:
+
+0x000100:       Initial sysfs support, as a single platform driver and
+                device.
diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c
index e47eaf72763d..a31d00d570cb 100644
--- a/drivers/misc/thinkpad_acpi.c
+++ b/drivers/misc/thinkpad_acpi.c
@@ -22,6 +22,7 @@
  */
 
 #define IBM_VERSION "0.14"
+#define TPACPI_SYSFS_VERSION 0x000100
 
 /*
  *  Changelog:
@@ -493,6 +494,87 @@ static struct platform_driver tpacpi_pdriver = {
 };
 
 
+/*************************************************************************
+ * thinkpad-acpi driver attributes
+ */
+
+/* interface_version --------------------------------------------------- */
+static ssize_t tpacpi_driver_interface_version_show(
+                                struct device_driver *drv,
+                                char *buf)
+{
+        return snprintf(buf, PAGE_SIZE, "0x%08x\n", TPACPI_SYSFS_VERSION);
+}
+
+static DRIVER_ATTR(interface_version, S_IRUGO,
+                tpacpi_driver_interface_version_show, NULL);
+
+/* debug_level --------------------------------------------------------- */
+static ssize_t tpacpi_driver_debug_show(struct device_driver *drv,
+                                                char *buf)
+{
+        return snprintf(buf, PAGE_SIZE, "0x%04x\n", dbg_level);
+}
+
+static ssize_t tpacpi_driver_debug_store(struct device_driver *drv,
+                                                const char *buf, size_t count)
+{
+        unsigned long t;
+        char *endp;
+
+        t = simple_strtoul(buf, &endp, 0);
+        while (*endp && isspace(*endp))
+                endp++;
+        if (*endp)
+                return -EINVAL;
+
+        dbg_level = t;
+
+        return count;
+}
+
+static DRIVER_ATTR(debug_level, S_IWUSR | S_IRUGO,
+                tpacpi_driver_debug_show, tpacpi_driver_debug_store);
+
+/* version ------------------------------------------------------------- */
+static ssize_t tpacpi_driver_version_show(struct device_driver *drv,
+                                                char *buf)
+{
+        return snprintf(buf, PAGE_SIZE, "%s v%s\n", IBM_DESC, IBM_VERSION);
+}
+
+static DRIVER_ATTR(version, S_IRUGO,
+                tpacpi_driver_version_show, NULL);
+
+/* --------------------------------------------------------------------- */
+
+static struct driver_attribute* tpacpi_driver_attributes[] = {
+        &driver_attr_debug_level, &driver_attr_version,
+        &driver_attr_interface_version,
+};
+
+static int __init tpacpi_create_driver_attributes(struct device_driver *drv)
+{
+        int i, res;
+
+        i = 0;
+        res = 0;
+        while (!res && i < ARRAY_SIZE(tpacpi_driver_attributes)) {
+                res = driver_create_file(drv, tpacpi_driver_attributes[i]);
+                i++;
+        }
+
+        return res;
+}
+
+static void tpacpi_remove_driver_attributes(struct device_driver *drv)
+{
+        int i;
+
+        for(i = 0; i < ARRAY_SIZE(tpacpi_driver_attributes); i++)
+                driver_remove_file(drv, tpacpi_driver_attributes[i]);
+}
+
 /****************************************************************************
  ****************************************************************************
  *
@@ -3268,6 +3350,13 @@ static int __init thinkpad_acpi_module_init(void)
                 thinkpad_acpi_module_exit();
                 return ret;
         }
+        ret = tpacpi_create_driver_attributes(&tpacpi_pdriver.driver);
+        if (ret) {
+                printk(IBM_ERR "unable to create sysfs driver attributes\n");
+                thinkpad_acpi_module_exit();
+                return ret;
+        }
+
 
         /* Device initialization */
         tpacpi_pdev = platform_device_register_simple(IBM_DRVR_NAME, -1,
@@ -3318,6 +3407,7 @@ static void thinkpad_acpi_module_exit(void)
         if (tpacpi_pdev)
                 platform_device_unregister(tpacpi_pdev);
 
+        tpacpi_remove_driver_attributes(&tpacpi_pdriver.driver);
         platform_driver_unregister(&tpacpi_pdriver);
 
         if (proc_dir)
diff --git a/drivers/misc/thinkpad_acpi.h b/drivers/misc/thinkpad_acpi.h
index fea580999e94..37860582956f 100644
--- a/drivers/misc/thinkpad_acpi.h
+++ b/drivers/misc/thinkpad_acpi.h
@@ -32,6 +32,7 @@
 #include <linux/list.h>
 
 #include <linux/proc_fs.h>
+#include <linux/sysfs.h>
 #include <linux/backlight.h>
 #include <linux/fb.h>
 #include <linux/platform_device.h>
@@ -137,6 +138,8 @@ static char *next_cmd(char **cmds);
 static struct platform_device *tpacpi_pdev;
 static struct class_device *tpacpi_hwmon;
 static struct platform_driver tpacpi_pdriver;
+static int tpacpi_create_driver_attributes(struct device_driver *drv);
+static void tpacpi_remove_driver_attributes(struct device_driver *drv);
 
 /* Module */
 static int experimental;