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 56eb471b557..055bcaba774 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 5a240c60342..008f96aaf19 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 cd6268cf7cd..fc160f72dc4 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 4a4e182c33e..81ee7551148 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 515cfe79054..3d6f548dd3d 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"
+	depends on TTY
 	select SERIO
 	help
 	  Say Y here if you have the Fujitsu touchscreen (such as one
@@ -275,6 +280,8 @@ config TOUCHSCREEN_S3C2410
 	  To compile this driver as a module, choose M here: the
 	  module will be called s3c2410_ts.
 
+if TTY
+
 config TOUCHSCREEN_GUNZE
 	tristate "Gunze AHL-51S touchscreen"
 	select SERIO
@@ -311,6 +318,8 @@ config TOUCHSCREEN_WACOM_W8001
 	  To compile this driver as a module, choose M here: the
 	  module will be called wacom_w8001.
 
+endif # TTY
+
 config TOUCHSCREEN_WACOM_I2C
 	tristate "Wacom Tablet support (I2C)"
 	depends on I2C
@@ -369,6 +378,8 @@ config TOUCHSCREEN_MMS114
 	  To compile this driver as a module, choose M here: the
 	  module will be called mms114.
 
+if TTY
+
 config TOUCHSCREEN_MTOUCH
 	tristate "MicroTouch serial touchscreens"
 	select SERIO
@@ -393,6 +404,8 @@ config TOUCHSCREEN_INEXIO
 	  To compile this driver as a module, choose M here: the
 	  module will be called inexio.
 
+endif # TTY
+
 config TOUCHSCREEN_INTEL_MID
 	tristate "Intel MID platform resistive touchscreen"
 	depends on INTEL_SCU_IPC
@@ -450,6 +463,7 @@ config TOUCHSCREEN_HTCPEN
 
 config TOUCHSCREEN_PENMOUNT
 	tristate "Penmount serial touchscreen"
+	depends on TTY
 	select SERIO
 	help
 	  Say Y here if you have a Penmount serial touchscreen connected to
@@ -493,6 +507,8 @@ config TOUCHSCREEN_TNETV107X
 	  To compile this driver as a module, choose M here: the
 	  module will be called tnetv107x-ts.
 
+if TTY
+
 config TOUCHSCREEN_TOUCHRIGHT
 	tristate "Touchright serial touchscreen"
 	select SERIO
@@ -517,6 +533,8 @@ config TOUCHSCREEN_TOUCHWIN
 	  To compile this driver as a module, choose M here: the
 	  module will be called touchwin.
 
+endif # TTY
+
 config TOUCHSCREEN_TI_AM335X_TSC
 	tristate "TI Touchscreen Interface"
 	depends on MFD_TI_AM335X_TSCADC
@@ -790,6 +808,8 @@ config TOUCHSCREEN_USB_EASYTOUCH
 	  Say Y here if you have an EasyTouch USB Touch controller.
 	  If unsure, say N.
 
+if TTY
+
 config TOUCHSCREEN_TOUCHIT213
 	tristate "Sahara TouchIT-213 touchscreen"
 	select SERIO
@@ -813,6 +833,8 @@ config TOUCHSCREEN_TSC_SERIO
 	  To compile this driver as a module, choose M here: the
 	  module will be called tsc40.
 
+endif # TTY
+
 config TOUCHSCREEN_TSC2005
         tristate "TSC2005 based touchscreens"
         depends on SPI_MASTER && GENERIC_HARDIRQS