gpiolib: allow user-selection
This patch adds functionality to the gpio-lib subsystem to make it
possible to enable the gpio-lib code even if the architecture code didn't
request to get it built in.
The archtitecture code does still need to implement the gpiolib accessor
functions in its asm/gpio.h file. This patch adds the implementations for
x86 and PPC.
With these changes it is possible to run generic GPIO expansion cards on
every architecture that implements the trivial wrapper functions. Support
for more architectures can easily be added.
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: David Brownell <david-b@pacbell.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Samuel Ortiz <sameo@openedhand.com>
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt
index 8b69811..18022e2 100644
--- a/Documentation/gpio.txt
+++ b/Documentation/gpio.txt
@@ -389,11 +389,21 @@
Platform Support
----------------
-To support this framework, a platform's Kconfig will "select HAVE_GPIO_LIB"
+To support this framework, a platform's Kconfig will "select" either
+ARCH_REQUIRE_GPIOLIB or ARCH_WANT_OPTIONAL_GPIOLIB
and arrange that its <asm/gpio.h> includes <asm-generic/gpio.h> and defines
three functions: gpio_get_value(), gpio_set_value(), and gpio_cansleep().
They may also want to provide a custom value for ARCH_NR_GPIOS.
+ARCH_REQUIRE_GPIOLIB means that the gpio-lib code will always get compiled
+into the kernel on that architecture.
+
+ARCH_WANT_OPTIONAL_GPIOLIB means the gpio-lib code defaults to off and the user
+can enable it and build it into the kernel optionally.
+
+If neither of these options are selected, the platform does not support
+GPIOs through GPIO-lib and the code cannot be enabled by the user.
+
Trivial implementations of those functions can directly use framework
code, which always dispatches through the gpio_chip:
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 6fb4f03..dabb015 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -268,7 +268,7 @@
select GENERIC_GPIO
select HAVE_CLK
select HAVE_CLK
- select HAVE_GPIO_LIB
+ select ARCH_REQUIRE_GPIOLIB
help
This enables support for the Cirrus EP93xx series of CPUs.
@@ -447,7 +447,7 @@
select ARCH_MTD_XIP
select GENERIC_GPIO
select HAVE_CLK
- select HAVE_GPIO_LIB
+ select ARCH_REQUIRE_GPIOLIB
select GENERIC_TIME
select GENERIC_CLOCKEVENTS
select TICK_ONESHOT
@@ -479,7 +479,7 @@
select GENERIC_CLOCKEVENTS
select HAVE_CLK
select TICK_ONESHOT
- select HAVE_GPIO_LIB
+ select ARCH_REQUIRE_GPIOLIB
help
Support for StrongARM 11x0 based boards.
@@ -522,7 +522,7 @@
bool "TI OMAP"
select GENERIC_GPIO
select HAVE_CLK
- select HAVE_GPIO_LIB
+ select ARCH_REQUIRE_GPIOLIB
select GENERIC_TIME
select GENERIC_CLOCKEVENTS
help
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index df4adef..7c239a9 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -88,7 +88,7 @@
select SUBARCH_AVR32B
select MMU
select PERFORMANCE_COUNTERS
- select HAVE_GPIO_LIB
+ select ARCH_REQUIRE_GPIOLIB
select GENERIC_ALLOCATOR
#
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index b9c754f..b4c4eaa 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -713,7 +713,7 @@
config GPIO_TXX9
select GENERIC_GPIO
- select HAVE_GPIO_LIB
+ select ARCH_REQUIRE_GPIOLIB
bool
config CFE
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index de6b49c..fe88418 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -110,6 +110,7 @@
default y
select HAVE_DYNAMIC_FTRACE
select HAVE_FTRACE
+ select ARCH_WANT_OPTIONAL_GPIOLIB
select HAVE_IDE
select HAVE_IOREMAP_PROT
select HAVE_EFFICIENT_UNALIGNED_ACCESS
diff --git a/arch/powerpc/platforms/52xx/Kconfig b/arch/powerpc/platforms/52xx/Kconfig
index d664b1b..ccbd495 100644
--- a/arch/powerpc/platforms/52xx/Kconfig
+++ b/arch/powerpc/platforms/52xx/Kconfig
@@ -48,6 +48,6 @@
config PPC_MPC5200_GPIO
bool "MPC5200 GPIO support"
depends on PPC_MPC52xx
- select HAVE_GPIO_LIB
+ select ARCH_REQUIRE_GPIOLIB
help
Enable gpiolib support for mpc5200 based boards
diff --git a/arch/powerpc/sysdev/qe_lib/Kconfig b/arch/powerpc/sysdev/qe_lib/Kconfig
index 4bb18f5..1ce5464 100644
--- a/arch/powerpc/sysdev/qe_lib/Kconfig
+++ b/arch/powerpc/sysdev/qe_lib/Kconfig
@@ -29,7 +29,7 @@
bool "QE GPIO support"
depends on QUICC_ENGINE
select GENERIC_GPIO
- select HAVE_GPIO_LIB
+ select ARCH_REQUIRE_GPIOLIB
help
Say Y here if you're going to use hardware that connects to the
QE GPIOs.
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 66f3ab0..e3cba0b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -23,6 +23,7 @@
select HAVE_OPROFILE
select HAVE_IOREMAP_PROT
select HAVE_KPROBES
+ select ARCH_WANT_OPTIONAL_GPIOLIB if !X86_RDC321X
select HAVE_KRETPROBES
select HAVE_DYNAMIC_FTRACE
select HAVE_FTRACE
diff --git a/drivers/Makefile b/drivers/Makefile
index 808e0ae..54ec5e7 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -5,7 +5,7 @@
# Rewritten to use lists instead of if-statements.
#
-obj-$(CONFIG_HAVE_GPIO_LIB) += gpio/
+obj-y += gpio/
obj-$(CONFIG_PCI) += pci/
obj-$(CONFIG_PARISC) += parisc/
obj-$(CONFIG_RAPIDIO) += rapidio/
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index de202db..5a355f8 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -2,15 +2,40 @@
# GPIO infrastructure and expanders
#
-config HAVE_GPIO_LIB
+config ARCH_WANT_OPTIONAL_GPIOLIB
bool
help
+ Select this config option from the architecture Kconfig, if
+ it is possible to use gpiolib on the architecture, but let the
+ user decide whether to actually build it or not.
+ Select this instead of ARCH_REQUIRE_GPIOLIB, if your architecture does
+ not depend on GPIOs being available, but rather let the user
+ decide whether he needs it or not.
+
+config ARCH_REQUIRE_GPIOLIB
+ bool
+ select GPIOLIB
+ help
Platforms select gpiolib if they use this infrastructure
for all their GPIOs, usually starting with ones integrated
into SOC processors.
+ Selecting this from the architecture code will cause the gpiolib
+ code to always get built in.
-menu "GPIO Support"
- depends on HAVE_GPIO_LIB
+
+
+menuconfig GPIOLIB
+ bool "GPIO Support"
+ depends on ARCH_WANT_OPTIONAL_GPIOLIB || ARCH_REQUIRE_GPIOLIB
+ select GENERIC_GPIO
+ help
+ This enables GPIO support through the generic GPIO library.
+ You only need to enable this, if you also want to enable
+ one or more of the GPIO expansion card drivers below.
+
+ If unsure, say N.
+
+if GPIOLIB
config DEBUG_GPIO
bool "Debug GPIO calls"
@@ -116,4 +141,4 @@
SPI driver for Microchip MCP23S08 I/O expander. This provides
a GPIO interface supporting inputs and outputs.
-endmenu
+endif
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index eeb2f2b..8c45948 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -2,7 +2,7 @@
ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG
-obj-$(CONFIG_HAVE_GPIO_LIB) += gpiolib.o
+obj-$(CONFIG_GPIOLIB) += gpiolib.o
obj-$(CONFIG_GPIO_MAX7301) += max7301.o
obj-$(CONFIG_GPIO_MCP23S08) += mcp23s08.o
diff --git a/drivers/i2c/chips/Kconfig b/drivers/i2c/chips/Kconfig
index 50e0a46..a95cb94 100644
--- a/drivers/i2c/chips/Kconfig
+++ b/drivers/i2c/chips/Kconfig
@@ -126,7 +126,7 @@
config TPS65010
tristate "TPS6501x Power Management chips"
- depends on HAVE_GPIO_LIB
+ depends on GPIOLIB
default y if MACH_OMAP_H2 || MACH_OMAP_H3 || MACH_OMAP_OSK
help
If you say yes here you get support for the TPS6501x series of
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index bac9e97..1f57a99 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -36,7 +36,7 @@
config HTC_EGPIO
bool "HTC EGPIO support"
- depends on GENERIC_HARDIRQS && HAVE_GPIO_LIB && ARM
+ depends on GENERIC_HARDIRQS && GPIOLIB && ARM
help
This driver supports the CPLD egpio chip present on
several HTC phones. It provides basic support for input
@@ -52,7 +52,7 @@
config MFD_TC6393XB
bool "Support Toshiba TC6393XB"
- depends on HAVE_GPIO_LIB
+ depends on GPIOLIB
select MFD_CORE
help
Support for Toshiba Mobile IO Controller TC6393XB
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index 3a7a11a..1d7ec31 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -4,7 +4,7 @@
config OF_GPIO
def_bool y
- depends on OF && PPC_OF && HAVE_GPIO_LIB
+ depends on OF && PPC_OF && GPIOLIB
help
OpenFirmware GPIO accessors
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 1beff51..a3034d2 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -3,7 +3,7 @@
#include <linux/types.h>
-#ifdef CONFIG_HAVE_GPIO_LIB
+#ifdef CONFIG_GPIOLIB
#include <linux/compiler.h>
diff --git a/include/asm-mips/mach-generic/gpio.h b/include/asm-mips/mach-generic/gpio.h
index e6b376b..b4e7020 100644
--- a/include/asm-mips/mach-generic/gpio.h
+++ b/include/asm-mips/mach-generic/gpio.h
@@ -1,7 +1,7 @@
#ifndef __ASM_MACH_GENERIC_GPIO_H
#define __ASM_MACH_GENERIC_GPIO_H
-#ifdef CONFIG_HAVE_GPIO_LIB
+#ifdef CONFIG_GPIOLIB
#define gpio_get_value __gpio_get_value
#define gpio_set_value __gpio_set_value
#define gpio_cansleep __gpio_cansleep
diff --git a/include/asm-powerpc/gpio.h b/include/asm-powerpc/gpio.h
index 77ad3a8..ea04632 100644
--- a/include/asm-powerpc/gpio.h
+++ b/include/asm-powerpc/gpio.h
@@ -17,7 +17,7 @@
#include <linux/errno.h>
#include <asm-generic/gpio.h>
-#ifdef CONFIG_HAVE_GPIO_LIB
+#ifdef CONFIG_GPIOLIB
/*
* We don't (yet) implement inlined/rapid versions for on-chip gpios.
@@ -51,6 +51,6 @@
return -EINVAL;
}
-#endif /* CONFIG_HAVE_GPIO_LIB */
+#endif /* CONFIG_GPIOLIB */
#endif /* __ASM_POWERPC_GPIO_H */
diff --git a/include/asm-x86/gpio.h b/include/asm-x86/gpio.h
index ff87fca..116e914 100644
--- a/include/asm-x86/gpio.h
+++ b/include/asm-x86/gpio.h
@@ -1,6 +1,62 @@
+/*
+ * Generic GPIO API implementation for x86.
+ *
+ * Derived from the generic GPIO API for powerpc:
+ *
+ * Copyright (c) 2007-2008 MontaVista Software, Inc.
+ *
+ * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
#ifndef _ASM_I386_GPIO_H
#define _ASM_I386_GPIO_H
+#ifdef CONFIG_X86_RDC321X
#include <gpio.h>
+#else /* CONFIG_X86_RDC321X */
+
+#include <asm-generic/gpio.h>
+
+#ifdef CONFIG_GPIOLIB
+
+/*
+ * Just call gpiolib.
+ */
+static inline int gpio_get_value(unsigned int gpio)
+{
+ return __gpio_get_value(gpio);
+}
+
+static inline void gpio_set_value(unsigned int gpio, int value)
+{
+ __gpio_set_value(gpio, value);
+}
+
+static inline int gpio_cansleep(unsigned int gpio)
+{
+ return __gpio_cansleep(gpio);
+}
+
+/*
+ * Not implemented, yet.
+ */
+static inline int gpio_to_irq(unsigned int gpio)
+{
+ return -ENOSYS;
+}
+
+static inline int irq_to_gpio(unsigned int irq)
+{
+ return -EINVAL;
+}
+
+#endif /* CONFIG_GPIOLIB */
+
+#endif /* CONFIG_X86_RDC321X */
#endif /* _ASM_I386_GPIO_H */