support Thinkpad X1 Carbon 2nd generation's adaptive keyboard

Submit patch V4 to support Adaptive Keyboard on Thinkpad X1 Carbon 2nd
generation according to Tobias's comments.

Thanks,
Shuduo

>From b153a7b14791c6e01892c0e274e23eefd625fb8d Mon Sep 17 00:00:00 2001
From: Shuduo Sang <shuduo.sang@canonical.com>
Date: Mon, 3 Mar 2014 14:29:32 +0800
Subject: [PATCH] support thinkpad X1 Carbon's adaptive keyboard

Thinkpad X1 Carbon's adaptive keyboard has five modes including Home
mode, Web browser mode, Web conference mode, Function mode and Lay-flat
mode. We support Home mode and Function mode currently.

Signed-off-by: Bruce Ma <bruce.ma@canonical.com>
Signed-off-by: Shuduo Sang <shuduo.sang@canonical.com>
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

1 files changed, 102 insertions, 0 deletions

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index dcc833a0b2fd..d0f2a5330096 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -3437,6 +3437,106 @@ err_exit:
         return (res < 0)? res : 1;
 }
 
+/* Thinkpad X1 Carbon support 5 modes including Home mode, Web browser
+ * mode, Web conference mode, Function mode and Lay-flat mode.
+ * We support Home mode and Function mode currently.
+ *
+ * Will consider support rest of modes in future.
+ *
+ */
+enum ADAPTIVE_KEY_MODE {
+        HOME_MODE,
+        WEB_BROWSER_MODE,
+        WEB_CONFERENCE_MODE,
+        FUNCTION_MODE,
+        LAYFLAT_MODE
+};
+
+const int adaptive_keyboard_modes[] = {
+        HOME_MODE,
+/*      WEB_BROWSER_MODE = 2,
+        WEB_CONFERENCE_MODE = 3, */
+        FUNCTION_MODE
+};
+
+#define DFR_CHANGE_ROW                  0x101
+#define DFR_SHOW_QUICKVIEW_ROW          0x102
+
+/* press Fn key a while second, it will switch to Function Mode. Then
+ * release Fn key, previous mode be restored.
+ */
+static bool adaptive_keyboard_mode_is_saved;
+static int adaptive_keyboard_prev_mode;
+
+static int adaptive_keyboard_get_next_mode(int mode)
+{
+        size_t i;
+        size_t max_mode = ARRAY_SIZE(adaptive_keyboard_modes) - 1;
+
+        for (i = 0; i <= max_mode; i++) {
+                if (adaptive_keyboard_modes[i] == mode)
+                        break;
+        }
+
+        if (i >= max_mode)
+                i = 0;
+        else
+                i++;
+
+        return adaptive_keyboard_modes[i];
+}
+
+static bool adaptive_keyboard_hotkey_notify_hotkey(unsigned int scancode)
+{
+        u32 current_mode = 0;
+        int new_mode = 0;
+
+        switch (scancode) {
+        case DFR_CHANGE_ROW:
+                if (adaptive_keyboard_mode_is_saved) {
+                        new_mode = adaptive_keyboard_prev_mode;
+                        adaptive_keyboard_mode_is_saved = false;
+                } else {
+                        if (!acpi_evalf(
+                                        hkey_handle, &current_mode,
+                                        "GTRW", "dd", 0)) {
+                                pr_err("Cannot read adaptive keyboard mode\n");
+                                return false;
+                        } else {
+                                new_mode = adaptive_keyboard_get_next_mode(
+                                                current_mode);
+                        }
+                }
+
+                if (!acpi_evalf(hkey_handle, NULL, "STRW", "vd", new_mode)) {
+                        pr_err("Cannot set adaptive keyboard mode\n");
+                        return false;
+                }
+
+                return true;
+
+        case DFR_SHOW_QUICKVIEW_ROW:
+                if (!acpi_evalf(hkey_handle,
+                                &adaptive_keyboard_prev_mode,
+                                "GTRW", "dd", 0)) {
+                        pr_err("Cannot read adaptive keyboard mode\n");
+                        return false;
+                } else {
+                        adaptive_keyboard_mode_is_saved = true;
+
+                        if (!acpi_evalf(hkey_handle,
+                                        NULL, "STRW", "vd", FUNCTION_MODE)) {
+                                pr_err("Cannot set adaptive keyboard mode\n");
+                                return false;
+                        }
+                }
+                return true;
+
+        default:
+                return false;
+        }
+}
+
 static bool hotkey_notify_hotkey(const u32 hkey,
                                  bool *send_acpi_ev,
                                  bool *ignore_acpi_ev)
@@ -3456,6 +3556,8 @@ static bool hotkey_notify_hotkey(const u32 hkey,
                         *ignore_acpi_ev = true;
                 }
                 return true;
+        } else {
+                return adaptive_keyboard_hotkey_notify_hotkey(scancode);
         }
         return false;
 }