ACPI: thinkpad-acpi: add tablet-mode reporting

A quick study of the 0x5009/0x500A HKEY event on the X61t DSDT revealed the
existence of the EC HTAB register (EC 0x0f, bit 7), and a compare with the
X41t DSDT shows that HKEY.MHKG can be used to verify if the ThinkPad is
tablet-capable (MHKG present), and in tablet mode (bit 3 of MHKG return is
set).

Add an attribute to report this information, "hotkey_tablet_mode".  This
attribute has poll()/select() support, and can be used along with EV_SW
SW_TABLET_MODE to hook userspace to tablet events.

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

diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt
index 606af16..76cb428 100644 (file)
--- a/Documentation/laptops/thinkpad-acpi.txt
+++ b/Documentation/laptops/thinkpad-acpi.txt
@@ -313,6 +313,13 @@ sysfs notes:
 
                This attribute has poll()/select() support.
 
+       hotkey_tablet_mode:
+               If the ThinkPad has tablet capabilities, this attribute
+               will read 0 if the ThinkPad is in normal mode, and
+               1 if the ThinkPad is in tablet mode.
+
+               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),

diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c
index c119cf2..bb269d0 100644 (file)
--- a/drivers/misc/thinkpad_acpi.c
+++ b/drivers/misc/thinkpad_acpi.c
@@ -221,6 +221,7 @@ static struct {
        u32 hotkey:1;
        u32 hotkey_mask:1;
        u32 hotkey_wlsw:1;
+       u32 hotkey_tablet:1;
        u32 light:1;
        u32 light_status:1;
        u32 bright_16levels:1;
@@ -1060,6 +1061,9 @@ static struct attribute_set *hotkey_dev_attributes;
 #define HOTKEY_CONFIG_CRITICAL_END
 #endif /* CONFIG_THINKPAD_ACPI_HOTKEY_POLL */
 
+/* HKEY.MHKG() return bits */
+#define TP_HOTKEY_TABLET_MASK (1 << 3)
+
 static int hotkey_get_wlsw(int *status)
 {
        if (!acpi_evalf(hkey_handle, status, "WLSW", "d"))
@@ -1067,6 +1071,16 @@ static int hotkey_get_wlsw(int *status)
        return 0;
 }
 
+static int hotkey_get_tablet_mode(int *status)
+{
+       int s;
+
+       if (!acpi_evalf(hkey_handle, &s, "MHKG", "d"))
+               return -EIO;
+
+       return ((s & TP_HOTKEY_TABLET_MASK) != 0);
+}
+
 /*
  * Call with hotkey_mutex held
  */
@@ -1172,15 +1186,20 @@ static void tpacpi_input_send_radiosw(void)
        }
 }
 
-static void tpacpi_input_send_tabletsw(unsigned int state)
+static void tpacpi_input_send_tabletsw(void)
 {
-       mutex_lock(&tpacpi_inputdev_send_mutex);
+       int state;
 
-       input_report_switch(tpacpi_inputdev,
-                           SW_TABLET_MODE, !!state);
-       input_sync(tpacpi_inputdev);
+       if (tp_features.hotkey_tablet &&
+           !hotkey_get_tablet_mode(&state)) {
+               mutex_lock(&tpacpi_inputdev_send_mutex);
 
-       mutex_unlock(&tpacpi_inputdev_send_mutex);
+               input_report_switch(tpacpi_inputdev,
+                                   SW_TABLET_MODE, !!state);
+               input_sync(tpacpi_inputdev);
+
+               mutex_unlock(&tpacpi_inputdev_send_mutex);
+       }
 }
 
 static void tpacpi_input_send_key(unsigned int scancode)
@@ -1691,6 +1710,29 @@ static void hotkey_radio_sw_notify_change(void)
                             "hotkey_radio_sw");
 }
 
+/* sysfs hotkey tablet mode (pollable) --------------------------------- */
+static ssize_t hotkey_tablet_mode_show(struct device *dev,
+                          struct device_attribute *attr,
+                          char *buf)
+{
+       int res, s;
+       res = hotkey_get_tablet_mode(&s);
+       if (res < 0)
+               return res;
+
+       return snprintf(buf, PAGE_SIZE, "%d\n", !!s);
+}
+
+static struct device_attribute dev_attr_hotkey_tablet_mode =
+       __ATTR(hotkey_tablet_mode, S_IRUGO, hotkey_tablet_mode_show, NULL);
+
+static void hotkey_tablet_mode_notify_change(void)
+{
+       if (tp_features.hotkey_tablet)
+               sysfs_notify(&tpacpi_pdev->dev.kobj, NULL,
+                            "hotkey_tablet_mode");
+}
+
 /* sysfs hotkey report_mode -------------------------------------------- */
 static ssize_t hotkey_report_mode_show(struct device *dev,
                           struct device_attribute *attr,
@@ -1903,7 +1945,7 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
                str_supported(tp_features.hotkey));
 
        if (tp_features.hotkey) {
-               hotkey_dev_attributes = create_attr_set(12, NULL);
+               hotkey_dev_attributes = create_attr_set(13, NULL);
                if (!hotkey_dev_attributes)
                        return -ENOMEM;
                res = add_many_to_attr_set(hotkey_dev_attributes,
@@ -1982,6 +2024,18 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
                                        &dev_attr_hotkey_radio_sw.attr);
                }
 
+               /* For X41t, X60t, X61t Tablets... */
+               if (!res && acpi_evalf(hkey_handle, &status, "MHKG", "qd")) {
+                       tp_features.hotkey_tablet = 1;
+                       printk(TPACPI_INFO
+                               "possible tablet mode switch found; "
+                               "ThinkPad in %s mode\n",
+                               (status & TP_HOTKEY_TABLET_MASK)?
+                                       "tablet" : "laptop");
+                       res = add_to_attr_set(hotkey_dev_attributes,
+                                       &dev_attr_hotkey_tablet_mode.attr);
+               }
+
                if (!res)
                        res = register_attr_set_with_sysfs(
                                        hotkey_dev_attributes,
@@ -2031,7 +2085,7 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
                        set_bit(EV_SW, tpacpi_inputdev->evbit);
                        set_bit(SW_RADIO, tpacpi_inputdev->swbit);
                }
-               if (thinkpad_id.vendor == PCI_VENDOR_ID_LENOVO) {
+               if (tp_features.hotkey_tablet) {
                        set_bit(EV_SW, tpacpi_inputdev->evbit);
                        set_bit(SW_TABLET_MODE, tpacpi_inputdev->swbit);
                }
@@ -2057,6 +2111,7 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
 
                hotkey_poll_setup_safe(1);
                tpacpi_input_send_radiosw();
+               tpacpi_input_send_tabletsw();
        }
 
        return (tp_features.hotkey)? 0 : 1;
@@ -2187,9 +2242,10 @@ static void hotkey_notify(struct ibm_struct *ibm, u32 event)
                        case 0x500b: /* X61t: tablet pen inserted into bay */
                        case 0x500c: /* X61t: tablet pen removed from bay */
                                break;
-                       case 0x5009: /* X61t: swivel up (tablet mode) */
-                       case 0x500a: /* X61t: swivel down (normal mode) */
-                               tpacpi_input_send_tabletsw((hkey == 0x5009));
+                       case 0x5009: /* X41t-X61t: swivel up (tablet mode) */
+                       case 0x500a: /* X41t-X61t: swivel down (normal mode) */
+                               tpacpi_input_send_tabletsw();
+                               hotkey_tablet_mode_notify_change();
                                send_acpi_ev = 0;
                                break;
                        case 0x5001:
@@ -2250,6 +2306,7 @@ static void hotkey_resume(void)
                       "from firmware\n");
        tpacpi_input_send_radiosw();
        hotkey_radio_sw_notify_change();
+       hotkey_tablet_mode_notify_change();
        hotkey_wakeup_reason_notify_change();
        hotkey_wakeup_hotunplug_complete_notify_change();
        hotkey_poll_setup_safe(0);