ACPI: thinkpad-acpi: revert new 2.6.23 CONFIG_THINKPAD_ACPI_INPUT_ENABLED option

Revert new 2.6.23 CONFIG_THINKPAD_ACPI_INPUT_ENABLED Kconfig option because
it would create a legacy we don't want to support.

CONFIG_THINKPAD_ACPI_INPUT_ENABLED was added to try to fix an issue that is
now moot with the addition of the netlink ACPI event report interface to
the ACPI core.

Now that ACPI core can send events over netlink, we can use a different
strategy to keep backwards compatibility with older userspace, without the
need for the CONFIG_THINKPAD_ACPI_INPUT_ENABLED games.  And it arrived
before CONFIG_THINKPAD_ACPI_INPUT_ENABLED made it to a stable mainline
kernel, even, which is Good.

This patch is in sync with some changes to thinkpad-acpi backports, that
will keep things sane for userspace across different combinations of kernel
versions, thinkpad-acpi backports (or the lack thereof), and userspace
capabilities:

Unless a module parameter is used, thinkpad-acpi will now behave in such a
way that it will work well (by default) with userspace that still uses only
the old ACPI procfs event interface and doesn't care for thinkpad-acpi
input devices.

It will also always work well with userspace that has been updated to use
both the thinkpad-acpi input devices, and ACPI core netlink event
interface, regardless of any module parameter.

The module parameter was added to allow thinkpad-acpi to work with
userspace that has been partially updated to use thinkpad-acpi input
devices, but not the new ACPI core netlink event interface.  To use this
mode of hot key reporting, one has to specify the hotkey_report_mode=2
module parameter.

The thinkpad-acpi driver exports the value of hotkey_report_mode through
sysfs, as well.  thinkpad-acpi backports to older kernels, that do not
support the new ACPI core netlink interface, have code to allow userspace
to switch hotkey_report_mode at runtime through sysfs.  This capability
will not be provided in mainline thinkpad-acpi as it is not needed there.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Michael S. Tsirkin <mst@dev.mellanox.co.il>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Richard Hughes <hughsient@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>

3 files changed, 87 insertions, 76 deletions

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index a26655881e6a..73e248fb2ff1 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -202,25 +202,5 @@ config THINKPAD_ACPI_BAY
 
           If you are not sure, say Y here.
 
-config THINKPAD_ACPI_INPUT_ENABLED
-        bool "Enable input layer support by default"
-        depends on THINKPAD_ACPI
-        default n
-        ---help---
-          This option enables thinkpad-acpi hot key handling over the input
-          layer at driver load time.  When it is unset, the driver does not
-          enable hot key handling by default, and also starts up with a mostly
-          empty keymap.
-
-          This option should be enabled if you have a new enough HAL or other
-          userspace support that properly handles the thinkpad-acpi event
-          device.  It auto-tunes the hot key support to those reported by the
-          firmware and enables it automatically.
-
-          If unsure, say N here to retain the old behaviour of ibm-acpi, and
-          thinkpad-acpi up to kernel 2.6.21: userspace will have to enable and
-          set up the thinkpad-acpi hot key handling using the sysfs interace
-          after loading the driver.
-
 
 endif # MISC_DEVICES
diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c
index bb8956d0c104..3d849d13657d 100644
--- a/drivers/misc/thinkpad_acpi.c
+++ b/drivers/misc/thinkpad_acpi.c
@@ -906,9 +906,26 @@ 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);
 
+/* sysfs hotkey report_mode -------------------------------------------- */
+static ssize_t hotkey_report_mode_show(struct device *dev,
+                           struct device_attribute *attr,
+                           char *buf)
+{
+        return snprintf(buf, PAGE_SIZE, "%d\n",
+                (hotkey_report_mode != 0) ? hotkey_report_mode : 1);
+}
+
+static struct device_attribute dev_attr_hotkey_report_mode =
+        __ATTR(hotkey_report_mode, S_IRUGO, hotkey_report_mode_show, NULL);
+
 /* --------------------------------------------------------------------- */
 
-static struct attribute *hotkey_mask_attributes[] = {
+static struct attribute *hotkey_attributes[] __initdata = {
+        &dev_attr_hotkey_enable.attr,
+        &dev_attr_hotkey_report_mode.attr,
+};
+
+static struct attribute *hotkey_mask_attributes[] __initdata = {
         &dev_attr_hotkey_mask.attr,
         &dev_attr_hotkey_bios_enabled.attr,
         &dev_attr_hotkey_bios_mask.attr,
@@ -987,11 +1004,12 @@ 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(7, NULL);
+                hotkey_dev_attributes = create_attr_set(8, NULL);
                 if (!hotkey_dev_attributes)
                         return -ENOMEM;
-                res = add_to_attr_set(hotkey_dev_attributes,
-                                &dev_attr_hotkey_enable.attr);
+                res = add_many_to_attr_set(hotkey_dev_attributes,
+                                hotkey_attributes,
+                                ARRAY_SIZE(hotkey_attributes));
                 if (res)
                         return res;
 
@@ -1055,11 +1073,6 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
                                 TPACPI_HOTKEY_MAP_SIZE);
                 }
 
-#ifndef CONFIG_THINKPAD_ACPI_INPUT_ENABLED
-                for (i = 0; i < 12; i++)
-                        hotkey_keycode_map[i] = KEY_UNKNOWN;
-#endif /* ! CONFIG_THINKPAD_ACPI_INPUT_ENABLED */
-
                 set_bit(EV_KEY, tpacpi_inputdev->evbit);
                 set_bit(EV_MSC, tpacpi_inputdev->evbit);
                 set_bit(MSC_SCAN, tpacpi_inputdev->mscbit);
@@ -1081,14 +1094,17 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
                         set_bit(SW_RADIO, tpacpi_inputdev->swbit);
                 }
 
-#ifdef CONFIG_THINKPAD_ACPI_INPUT_ENABLED
                 dbg_printk(TPACPI_DBG_INIT,
                                 "enabling hot key handling\n");
                 res = hotkey_set(1, (hotkey_all_mask & ~hotkey_reserved_mask)
                                         | hotkey_orig_mask);
                 if (res)
                         return res;
-#endif /* CONFIG_THINKPAD_ACPI_INPUT_ENABLED */
+
+                dbg_printk(TPACPI_DBG_INIT,
+                                "legacy hot key reporting over procfs %s\n",
+                                (hotkey_report_mode < 2) ?
+                                        "enabled" : "disabled");
         }
 
         return (tp_features.hotkey)? 0 : 1;
@@ -1142,58 +1158,65 @@ static void hotkey_notify(struct ibm_struct *ibm, u32 event)
 {
         u32 hkey;
         unsigned int keycode, scancode;
-        int sendacpi = 1;
+        int send_acpi_ev = 0;
 
         if (event == 0x80 && acpi_evalf(hkey_handle, &hkey, "MHKP", "d")) {
-                if (tpacpi_inputdev->users > 0) {
-                        switch (hkey >> 12) {
-                        case 1:
-                                /* 0x1000-0x1FFF: key presses */
-                                scancode = hkey & 0xfff;
-                                if (scancode > 0 && scancode < 0x21) {
-                                        scancode--;
-                                        keycode = hotkey_keycode_map[scancode];
-                                        tpacpi_input_send_key(scancode, keycode);
-                                        sendacpi = (keycode == KEY_RESERVED
-                                                || keycode == KEY_UNKNOWN);
-                                } else {
-                                        printk(IBM_ERR
-                                               "hotkey 0x%04x out of range for keyboard map\n",
-                                               hkey);
-                                }
-                                break;
-                        case 5:
-                                /* 0x5000-0x5FFF: LID */
-                                /* we don't handle it through this path, just
-                                 * eat up known LID events */
-                                if (hkey != 0x5001 && hkey != 0x5002) {
-                                        printk(IBM_ERR
-                                                "unknown LID-related hotkey event: 0x%04x\n",
-                                                hkey);
-                                }
+                switch (hkey >> 12) {
+                case 1:
+                        /* 0x1000-0x1FFF: key presses */
+                        scancode = hkey & 0xfff;
+                        if (scancode > 0 && scancode < 0x21) {
+                                scancode--;
+                                keycode = hotkey_keycode_map[scancode];
+                                tpacpi_input_send_key(scancode, keycode);
+                        } else {
+                                printk(IBM_ERR
+                                       "hotkey 0x%04x out of range for keyboard map\n",
+                                       hkey);
+                                send_acpi_ev = 1;
+                        }
+                        break;
+                case 5:
+                        /* 0x5000-0x5FFF: LID */
+                        /* we don't handle it through this path, just
+                         * eat up known LID events */
+                        if (hkey != 0x5001 && hkey != 0x5002) {
+                                printk(IBM_ERR
+                                        "unknown LID-related hotkey event: 0x%04x\n",
+                                        hkey);
+                                send_acpi_ev = 1;
+                        }
+                        break;
+                case 7:
+                        /* 0x7000-0x7FFF: misc */
+                        if (tp_features.hotkey_wlsw && hkey == 0x7000) {
+                                tpacpi_input_send_radiosw();
                                 break;
-                        case 7:
-                                /* 0x7000-0x7FFF: misc */
-                                if (tp_features.hotkey_wlsw && hkey == 0x7000) {
-                                                tpacpi_input_send_radiosw();
-                                                sendacpi = 0;
-                                        break;
-                                }
-                                /* fallthrough to default */
-                        default:
-                                /* case 2: dock-related */
-                                /*      0x2305 - T43 waking up due to bay lever eject while aslept */
-                                /* case 3: ultra-bay related. maybe bay in dock? */
-                                /*      0x3003 - T43 after wake up by bay lever eject (0x2305) */
-                                printk(IBM_NOTICE "unhandled hotkey event 0x%04x\n", hkey);
                         }
+                        /* fallthrough to default */
+                default:
+                        /* case 2: dock-related */
+                        /*      0x2305 - T43 waking up due to bay lever eject while aslept */
+                        /* case 3: ultra-bay related. maybe bay in dock? */
+                        /*      0x3003 - T43 after wake up by bay lever eject (0x2305) */
+                        printk(IBM_NOTICE "unhandled HKEY event 0x%04x\n", hkey);
+                        send_acpi_ev = 1;
                 }
-
-                if (sendacpi)
-                        acpi_bus_generate_proc_event(ibm->acpi->device, event, hkey);
         } else {
                 printk(IBM_ERR "unknown hotkey notification event %d\n", event);
-                acpi_bus_generate_proc_event(ibm->acpi->device, event, 0);
+                hkey = 0;
+                send_acpi_ev = 1;
+        }
+
+        /* Legacy events */
+        if (send_acpi_ev || hotkey_report_mode < 2)
+                acpi_bus_generate_proc_event(ibm->acpi->device, event, hkey);
+
+        /* netlink events */
+        if (send_acpi_ev) {
+                acpi_bus_generate_netlink_event(ibm->acpi->device->pnp.device_class,
+                                                ibm->acpi->device->dev.bus_id,
+                                                event, hkey);
         }
 }
 
@@ -4623,6 +4646,9 @@ module_param_named(fan_control, fan_control_allowed, bool, 0);
 static int brightness_mode;
 module_param_named(brightness_mode, brightness_mode, int, 0);
 
+static unsigned int hotkey_report_mode;
+module_param(hotkey_report_mode, uint, 0);
+
 #define IBM_PARAM(feature) \
         module_param_call(feature, set_ibm_param, NULL, NULL, 0)
 
@@ -4648,6 +4674,10 @@ static int __init thinkpad_acpi_module_init(void)
 {
         int ret, i;
 
+        /* Parameter checking */
+        if (hotkey_report_mode > 2)
+                return -EINVAL;
+
         /* Driver-level probe */
 
         get_thinkpad_model_data(&thinkpad_id);
diff --git a/drivers/misc/thinkpad_acpi.h b/drivers/misc/thinkpad_acpi.h
index eee8809a50d9..082a1cbc16c0 100644
--- a/drivers/misc/thinkpad_acpi.h
+++ b/drivers/misc/thinkpad_acpi.h
@@ -181,6 +181,7 @@ static void tpacpi_remove_driver_attributes(struct device_driver *drv);
 static int experimental;
 static u32 dbg_level;
 static int force_load;
+static unsigned int hotkey_report_mode;
 
 static int thinkpad_acpi_module_init(void);
 static void thinkpad_acpi_module_exit(void);