ACPI: thinkpad-acpi: add poll() support to some sysfs attributes

Implement poll()/select() support through sysfs_notify() for some key
attributes which userspace might want to poll() or select() on.

In order to let userspace know poll()/select() support is available for an
attribute, the thinkpad-acpi sysfs interface version is also bumped up.
Further changes that add poll()/select() capabilities to any pre-existing
attributes will also increment the sysfs interface version.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>

2 files changed, 41 insertions, 4 deletions

diff --git a/Documentation/thinkpad-acpi.txt b/Documentation/thinkpad-acpi.txt
index e1c4550dac99..9bbd0f541437 100644
--- a/Documentation/thinkpad-acpi.txt
+++ b/Documentation/thinkpad-acpi.txt
@@ -311,6 +311,8 @@ sysfs notes:
                 disabled" postition, and 1 if the switch is in the
                 "radios enabled" position.
 
+                This attribute has poll()/select() support.
+
         hotkey_report_mode:
                 Returns the state of the procfs ACPI event report mode
                 filter for hot keys.  If it is set to 1 (the default),
@@ -332,6 +334,8 @@ sysfs notes:
                 undock.  Set to zero for normal wake-ups or wake-ups
                 due to unknown reasons.
 
+                This attribute has poll()/select() support.
+
         wakeup_hotunplug_complete:
                 Set to 1 if the system was waken up because of an
                 undock or bay ejection request, and that request
@@ -340,6 +344,8 @@ sysfs notes:
                 user's choice.  Refer to HKEY events 0x4003 and
                 0x3003, below.
 
+                This attribute has poll()/select() support.
+
 input layer notes:
 
 A Hot key is mapped to a single input layer EV_KEY event, possibly
@@ -1354,3 +1360,6 @@ Sysfs interface changelog:
                 NVRAM polling patch).  Some development snapshots of
                 0.18 had an earlier version that did strange things
                 to hotkey_mask.
+
+0x020200:       Add poll()/select() support to the following attributes:
+                hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason
diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c
index e18f1e18781f..91bda316a51c 100644
--- a/drivers/misc/thinkpad_acpi.c
+++ b/drivers/misc/thinkpad_acpi.c
@@ -22,7 +22,7 @@
  */
 
 #define TPACPI_VERSION "0.18"
-#define TPACPI_SYSFS_VERSION 0x020101
+#define TPACPI_SYSFS_VERSION 0x020200
 
 /*
  *  Changelog:
@@ -1643,7 +1643,7 @@ static struct device_attribute dev_attr_hotkey_poll_freq =
 
 #endif /* CONFIG_THINKPAD_ACPI_HOTKEY_POLL */
 
-/* sysfs hotkey radio_sw ----------------------------------------------- */
+/* sysfs hotkey radio_sw (pollable) ------------------------------------ */
 static ssize_t hotkey_radio_sw_show(struct device *dev,
                            struct device_attribute *attr,
                            char *buf)
@@ -1659,6 +1659,13 @@ static ssize_t hotkey_radio_sw_show(struct device *dev,
 static struct device_attribute dev_attr_hotkey_radio_sw =
         __ATTR(hotkey_radio_sw, S_IRUGO, hotkey_radio_sw_show, NULL);
 
+static void hotkey_radio_sw_notify_change(void)
+{
+        if (tp_features.hotkey_wlsw)
+                sysfs_notify(&tpacpi_pdev->dev.kobj, NULL,
+                             "hotkey_radio_sw");
+}
+
 /* sysfs hotkey report_mode -------------------------------------------- */
 static ssize_t hotkey_report_mode_show(struct device *dev,
                            struct device_attribute *attr,
@@ -1671,7 +1678,7 @@ static ssize_t hotkey_report_mode_show(struct device *dev,
 static struct device_attribute dev_attr_hotkey_report_mode =
         __ATTR(hotkey_report_mode, S_IRUGO, hotkey_report_mode_show, NULL);
 
-/* sysfs wakeup reason ------------------------------------------------- */
+/* sysfs wakeup reason (pollable) -------------------------------------- */
 static ssize_t hotkey_wakeup_reason_show(struct device *dev,
                            struct device_attribute *attr,
                            char *buf)
@@ -1682,7 +1689,14 @@ static ssize_t hotkey_wakeup_reason_show(struct device *dev,
 static struct device_attribute dev_attr_hotkey_wakeup_reason =
         __ATTR(wakeup_reason, S_IRUGO, hotkey_wakeup_reason_show, NULL);
 
-/* sysfs wakeup hotunplug_complete ------------------------------------- */
+void hotkey_wakeup_reason_notify_change(void)
+{
+        if (tp_features.hotkey_mask)
+                sysfs_notify(&tpacpi_pdev->dev.kobj, NULL,
+                             "wakeup_reason");
+}
+
+/* sysfs wakeup hotunplug_complete (pollable) -------------------------- */
 static ssize_t hotkey_wakeup_hotunplug_complete_show(struct device *dev,
                            struct device_attribute *attr,
                            char *buf)
@@ -1694,6 +1708,13 @@ static struct device_attribute dev_attr_hotkey_wakeup_hotunplug_complete =
         __ATTR(wakeup_hotunplug_complete, S_IRUGO,
                hotkey_wakeup_hotunplug_complete_show, NULL);
 
+void hotkey_wakeup_hotunplug_complete_notify_change(void)
+{
+        if (tp_features.hotkey_mask)
+                sysfs_notify(&tpacpi_pdev->dev.kobj, NULL,
+                             "wakeup_hotunplug_complete");
+}
+
 /* --------------------------------------------------------------------- */
 
 static struct attribute *hotkey_attributes[] __initdata = {
@@ -2106,6 +2127,7 @@ static void hotkey_notify(struct ibm_struct *ibm, u32 event)
                                 printk(TPACPI_INFO
                                        "woke up due to a hot-unplug "
                                        "request...\n");
+                                hotkey_wakeup_reason_notify_change();
                         }
                         break;
                 case 3:
@@ -2114,6 +2136,7 @@ static void hotkey_notify(struct ibm_struct *ibm, u32 event)
                                 hotkey_autosleep_ack = 1;
                                 printk(TPACPI_INFO
                                        "bay ejected\n");
+                                hotkey_wakeup_hotunplug_complete_notify_change();
                         } else {
                                 unk_ev = 1;
                         }
@@ -2124,6 +2147,7 @@ static void hotkey_notify(struct ibm_struct *ibm, u32 event)
                                 hotkey_autosleep_ack = 1;
                                 printk(TPACPI_INFO
                                        "undocked\n");
+                                hotkey_wakeup_hotunplug_complete_notify_change();
                         } else {
                                 unk_ev = 1;
                         }
@@ -2150,6 +2174,7 @@ static void hotkey_notify(struct ibm_struct *ibm, u32 event)
                         /* 0x7000-0x7FFF: misc */
                         if (tp_features.hotkey_wlsw && hkey == 0x7000) {
                                 tpacpi_input_send_radiosw();
+                                hotkey_radio_sw_notify_change();
                                 send_acpi_ev = 0;
                                 break;
                         }
@@ -2193,6 +2218,9 @@ static void hotkey_resume(void)
                        "error while trying to read hot key mask "
                        "from firmware\n");
         tpacpi_input_send_radiosw();
+        hotkey_radio_sw_notify_change();
+        hotkey_wakeup_reason_notify_change();
+        hotkey_wakeup_hotunplug_complete_notify_change();
 #ifdef CONFIG_THINKPAD_ACPI_HOTKEY_POLL
         hotkey_poll_setup_safe(0);
 #endif