tty: Added a CONFIG_TTY option to allow removal of TTY

The option allows you to remove TTY and compile without errors. This
saves space on systems that won't support TTY interfaces anyway.
bloat-o-meter output is below.

The bulk of this patch consists of Kconfig changes adding "depends on
TTY" to various serial devices and similar drivers that require the TTY
layer.  Ideally, these dependencies would occur on a common intermediate
symbol such as SERIO, but most drivers "select SERIO" rather than
"depends on SERIO", and "select" does not respect dependencies.

bloat-o-meter output comparing our previous minimal to new minimal by
removing TTY.  The list is filtered to not show removed entries with awk
'$3 != "-"' as the list was very long.

add/remove: 0/226 grow/shrink: 2/14 up/down: 6/-35356 (-35350)
function                                     old     new   delta
chr_dev_init                                 166     170      +4
allow_signal                                  80      82      +2
static.__warned                              143     142      -1
disallow_signal                               63      62      -1
__set_special_pids                            95      94      -1
unregister_console                           126     121      -5
start_kernel                                 546     541      -5
register_console                             593     588      -5
copy_from_user                                45      40      -5
sys_setsid                                   128     120      -8
sys_vhangup                                   32      19     -13
do_exit                                     1543    1526     -17
bitmap_zero                                   60      40     -20
arch_local_irq_save                          137     117     -20
release_task                                 674     652     -22
static.spin_unlock_irqrestore                308     260     -48

Signed-off-by: Joe Millenbach <jmillenbach@gmail.com>
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

5 files changed, 39 insertions, 1 deletions

diff --git a/drivers/input/joystick/Kconfig b/drivers/input/joystick/Kconfig
index 56eb471b5576..055bcaba774c 100644
--- a/drivers/input/joystick/Kconfig
+++ b/drivers/input/joystick/Kconfig
@@ -132,6 +132,8 @@ config JOYSTICK_TMDC
 
 source "drivers/input/joystick/iforce/Kconfig"
 
+if TTY
+
 config JOYSTICK_WARRIOR
         tristate "Logitech WingMan Warrior joystick"
         select SERIO
@@ -205,6 +207,8 @@ config JOYSTICK_ZHENHUA
           To compile this driver as a module, choose M here: the
           module will be called zhenhua.
 
+endif # TTY
+
 config JOYSTICK_DB9
         tristate "Multisystem, Sega Genesis, Saturn joysticks and gamepads"
         depends on PARPORT
diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index 5a240c60342d..008f96aaf19e 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -69,6 +69,7 @@ config KEYBOARD_ATARI
 config KEYBOARD_ATKBD
         tristate "AT keyboard" if EXPERT || !X86
         default y
+        depends on TTY
         select SERIO
         select SERIO_LIBPS2
         select SERIO_I8042 if X86
@@ -153,6 +154,7 @@ config KEYBOARD_BFIN
 
 config KEYBOARD_LKKBD
         tristate "DECstation/VAXstation LK201/LK401 keyboard"
+        depends on TTY
         select SERIO
         help
           Say Y here if you want to use a LK201 or LK401 style serial
@@ -268,7 +270,7 @@ config KEYBOARD_HIL_OLD
 
 config KEYBOARD_HIL
         tristate "HP HIL keyboard/pointer support"
-        depends on GSC || HP300
+        depends on (GSC || HP300) && TTY
         default y
         select HP_SDC
         select HIL_MLC
@@ -400,6 +402,7 @@ config KEYBOARD_IMX
 
 config KEYBOARD_NEWTON
         tristate "Newton keyboard"
+        depends on TTY
         select SERIO
         help
           Say Y here if you have a Newton keyboard on a serial port.
@@ -479,6 +482,8 @@ config KEYBOARD_SAMSUNG
           To compile this driver as a module, choose M here: the
           module will be called samsung-keypad.
 
+if TTY
+
 config KEYBOARD_STOWAWAY
         tristate "Stowaway keyboard"
         select SERIO
@@ -501,6 +506,8 @@ config KEYBOARD_SUNKBD
           To compile this driver as a module, choose M here: the
           module will be called sunkbd.
 
+endif # TTY
+
 config KEYBOARD_SH_KEYSC
         tristate "SuperH KEYSC keypad support"
         depends on SUPERH || ARCH_SHMOBILE
@@ -597,6 +604,7 @@ config KEYBOARD_TWL4030
 
 config KEYBOARD_XTKBD
         tristate "XT keyboard"
+        depends on TTY
         select SERIO
         help
           Say Y here if you want to use the old IBM PC/XT keyboard (or
diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
index cd6268cf7cd5..fc160f72dc4e 100644
--- a/drivers/input/mouse/Kconfig
+++ b/drivers/input/mouse/Kconfig
@@ -14,6 +14,7 @@ if INPUT_MOUSE
 
 config MOUSE_PS2
         tristate "PS/2 mouse"
+        depends on TTY
         default y
         select SERIO
         select SERIO_LIBPS2
@@ -138,6 +139,7 @@ config MOUSE_PS2_OLPC
 
 config MOUSE_SERIAL
         tristate "Serial mouse"
+        depends on TTY
         select SERIO
         help
           Say Y here if you have a serial (RS-232, COM port) mouse connected
@@ -262,6 +264,7 @@ config MOUSE_RISCPC
 
 config MOUSE_VSXXXAA
         tristate "DEC VSXXX-AA/GA mouse and VSXXX-AB tablet"
+        depends on TTY
         select SERIO
         help
           Say Y (or M) if you want to use a DEC VSXXX-AA (hockey
diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
index 4a4e182c33e7..81ee7551148e 100644
--- a/drivers/input/serio/Kconfig
+++ b/drivers/input/serio/Kconfig
@@ -4,6 +4,7 @@
 config SERIO
         tristate "Serial I/O support" if EXPERT || !X86
         default y
+        depends on TTY
         help
           Say Yes here if you have any input device that uses serial I/O to
           communicate with the system. This includes the
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 515cfe790543..3d6f548dd3d4 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -192,6 +192,8 @@ config TOUCHSCREEN_DA9052
           To compile this driver as a module, choose M here: the
           module will be called da9052_tsi.
 
+if TTY
+
 config TOUCHSCREEN_DYNAPRO
         tristate "Dynapro serial touchscreen"
         select SERIO
@@ -216,6 +218,8 @@ config TOUCHSCREEN_HAMPSHIRE
           To compile this driver as a module, choose M here: the
           module will be called hampshire.
 
+endif # TTY
+
 config TOUCHSCREEN_EETI
         tristate "EETI touchscreen panel support"
         depends on I2C
@@ -237,6 +241,7 @@ config TOUCHSCREEN_EGALAX
 
 config TOUCHSCREEN_FUJITSU
         tristate "Fujitsu serial touchscreen"