Rather than requiring architectures that use gpiolib but don't have any
need to define anything custom to copy an asm/gpio.h provide a Kconfig
symbol which architectures must select in order to include gpio.h and
for other architectures just provide the trivial implementation directly.
This makes it much easier to do gpiolib updates and is also a step towards
making gpiolib APIs available on every architecture.
For architectures with existing boilerplate code leave a stub header in
place which warns on direct inclusion of asm/gpio.h and includes
linux/gpio.h to catch code that's doing this. Direct inclusion of
asm/gpio.h has long been deprecated.
Signed-off-by: Mark Brown <[email protected]>
---
Build tested on x86 which is one of the affected architectures.
arch/alpha/include/asm/gpio.h | 59 ++----------------------------
arch/arm/Kconfig | 1 +
arch/avr32/Kconfig | 1 +
arch/blackfin/Kconfig | 1 +
arch/ia64/include/asm/gpio.h | 59 ++----------------------------
arch/m68k/Kconfig.cpu | 1 +
arch/microblaze/include/asm/gpio.h | 57 ++---------------------------
arch/mips/Kconfig | 1 +
arch/openrisc/include/asm/gpio.h | 69 ++---------------------------------
arch/powerpc/include/asm/gpio.h | 57 ++---------------------------
arch/sh/Kconfig | 1 +
arch/sparc/include/asm/gpio.h | 40 ++-------------------
arch/unicore32/Kconfig | 1 +
arch/x86/include/asm/gpio.h | 57 ++---------------------------
arch/xtensa/include/asm/gpio.h | 60 ++-----------------------------
drivers/gpio/Kconfig | 8 ++++
include/linux/gpio.h | 34 +++++++++++++++++
17 files changed, 81 insertions(+), 426 deletions(-)
diff --git a/arch/alpha/include/asm/gpio.h b/arch/alpha/include/asm/gpio.h
index 7dc6a63..b3799d8 100644
--- a/arch/alpha/include/asm/gpio.h
+++ b/arch/alpha/include/asm/gpio.h
@@ -1,55 +1,4 @@
-/*
- * Generic GPIO API implementation for Alpha.
- *
- * A stright copy of that for PowerPC which was:
- *
- * Copyright (c) 2007-2008 MontaVista Software, Inc.
- *
- * Author: Anton Vorontsov <[email protected]>
- *
- * 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_ALPHA_GPIO_H
-#define _ASM_ALPHA_GPIO_H
-
-#include <linux/errno.h>
-#include <asm-generic/gpio.h>
-
-#ifdef CONFIG_GPIOLIB
-
-/*
- * We don't (yet) implement inlined/rapid versions for on-chip gpios.
- * 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);
-}
-
-static inline int gpio_to_irq(unsigned int gpio)
-{
- return __gpio_to_irq(gpio);
-}
-
-static inline int irq_to_gpio(unsigned int irq)
-{
- return -EINVAL;
-}
-
-#endif /* CONFIG_GPIOLIB */
-
-#endif /* _ASM_ALPHA_GPIO_H */
+#ifndef __LINUX_GPIO_H
+#warning Include linux/gpio.h instead of asm/gpio.h
+#include <linux/gpio.h>
+#endif
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a48aecc..dcf4187 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1,6 +1,7 @@
config ARM
bool
default y
+ select ARCH_HAVE_CUSTOM_GPIO_H
select HAVE_AOUT
select HAVE_DMA_API_DEBUG
select HAVE_IDE if PCI || ISA || PCMCIA
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index 197e96f..b2e3e58 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -10,6 +10,7 @@ config AVR32
select GENERIC_IRQ_PROBE
select HARDIRQS_SW_RESEND
select GENERIC_IRQ_SHOW
+ select ARCH_HAVE_CUSTOM_GPIO_H
select ARCH_HAVE_NMI_SAFE_CMPXCHG
help
AVR32 is a high-performance 32-bit RISC microprocessor core,
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index abe5a9e..c45ecdc 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -31,6 +31,7 @@ config BLACKFIN
select HAVE_KERNEL_LZO if RAMKERNEL
select HAVE_OPROFILE
select HAVE_PERF_EVENTS
+ select ARCH_HAVE_CUSTOM_GPIO_H
select ARCH_WANT_OPTIONAL_GPIOLIB
select HAVE_GENERIC_HARDIRQS
select GENERIC_ATOMIC64
diff --git a/arch/ia64/include/asm/gpio.h b/arch/ia64/include/asm/gpio.h
index 590a20d..b3799d8 100644
--- a/arch/ia64/include/asm/gpio.h
+++ b/arch/ia64/include/asm/gpio.h
@@ -1,55 +1,4 @@
-/*
- * Generic GPIO API implementation for IA-64.
- *
- * A stright copy of that for PowerPC which was:
- *
- * Copyright (c) 2007-2008 MontaVista Software, Inc.
- *
- * Author: Anton Vorontsov <[email protected]>
- *
- * 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_IA64_GPIO_H
-#define _ASM_IA64_GPIO_H
-
-#include <linux/errno.h>
-#include <asm-generic/gpio.h>
-
-#ifdef CONFIG_GPIOLIB
-
-/*
- * We don't (yet) implement inlined/rapid versions for on-chip gpios.
- * 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);
-}
-
-static inline int gpio_to_irq(unsigned int gpio)
-{
- return __gpio_to_irq(gpio);
-}
-
-static inline int irq_to_gpio(unsigned int irq)
-{
- return -EINVAL;
-}
-
-#endif /* CONFIG_GPIOLIB */
-
-#endif /* _ASM_IA64_GPIO_H */
+#ifndef __LINUX_GPIO_H
+#warning Include linux/gpio.h instead of asm/gpio.h
+#include <linux/gpio.h>
+#endif
diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu
index 8a9c767..8941af1 100644
--- a/arch/m68k/Kconfig.cpu
+++ b/arch/m68k/Kconfig.cpu
@@ -24,6 +24,7 @@ config COLDFIRE
bool "Coldfire CPU family support"
select GENERIC_GPIO
select ARCH_REQUIRE_GPIOLIB
+ select ARCH_HAVE_CUSTOM_GPIO_H
select CPU_HAS_NO_BITFIELDS
select CPU_HAS_NO_MULDIV64
select GENERIC_CSUM
diff --git a/arch/microblaze/include/asm/gpio.h b/arch/microblaze/include/asm/gpio.h
index 2b2c18b..b3799d8 100644
--- a/arch/microblaze/include/asm/gpio.h
+++ b/arch/microblaze/include/asm/gpio.h
@@ -1,53 +1,4 @@
-/*
- * Generic GPIO API implementation for PowerPC.
- *
- * Copyright (c) 2007-2008 MontaVista Software, Inc.
- *
- * Author: Anton Vorontsov <[email protected]>
- *
- * 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_MICROBLAZE_GPIO_H
-#define _ASM_MICROBLAZE_GPIO_H
-
-#include <linux/errno.h>
-#include <asm-generic/gpio.h>
-
-#ifdef CONFIG_GPIOLIB
-
-/*
- * We don't (yet) implement inlined/rapid versions for on-chip gpios.
- * 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);
-}
-
-static inline int gpio_to_irq(unsigned int gpio)
-{
- return __gpio_to_irq(gpio);
-}
-
-static inline int irq_to_gpio(unsigned int irq)
-{
- return -EINVAL;
-}
-
-#endif /* CONFIG_GPIOLIB */
-
-#endif /* _ASM_MICROBLAZE_GPIO_H */
+#ifndef __LINUX_GPIO_H
+#warning Include linux/gpio.h instead of asm/gpio.h
+#include <linux/gpio.h>
+#endif
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index c4c1312..4918404 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -8,6 +8,7 @@ config MIPS
select HAVE_PERF_EVENTS
select PERF_USE_VMALLOC
select HAVE_ARCH_KGDB
+ select ARCH_HAVE_CUSTOM_GPIO_H
select HAVE_FUNCTION_TRACER
select HAVE_FUNCTION_TRACE_MCOUNT_TEST
select HAVE_DYNAMIC_FTRACE
diff --git a/arch/openrisc/include/asm/gpio.h b/arch/openrisc/include/asm/gpio.h
index 0b0d174..b3799d8 100644
--- a/arch/openrisc/include/asm/gpio.h
+++ b/arch/openrisc/include/asm/gpio.h
@@ -1,65 +1,4 @@
-/*
- * OpenRISC Linux
- *
- * Linux architectural port borrowing liberally from similar works of
- * others. All original copyrights apply as per the original source
- * declaration.
- *
- * OpenRISC implementation:
- * Copyright (C) 2003 Matjaz Breskvar <[email protected]>
- * Copyright (C) 2010-2011 Jonas Bonn <[email protected]>
- * et al.
- *
- * 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_OPENRISC_GPIO_H
-#define __ASM_OPENRISC_GPIO_H
-
-#include <linux/errno.h>
-#include <asm-generic/gpio.h>
-
-#ifdef CONFIG_GPIOLIB
-
-/*
- * OpenRISC (or1k) does not have on-chip GPIO's so there is not really
- * any standardized implementation that makes sense here. If passing
- * through gpiolib becomes a bottleneck then it may make sense, on a
- * case-by-case basis, to implement these inlined/rapid versions.
- *
- * 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 /* __ASM_OPENRISC_GPIO_H */
+#ifndef __LINUX_GPIO_H
+#warning Include linux/gpio.h instead of asm/gpio.h
+#include <linux/gpio.h>
+#endif
diff --git a/arch/powerpc/include/asm/gpio.h b/arch/powerpc/include/asm/gpio.h
index 38762ed..b3799d8 100644
--- a/arch/powerpc/include/asm/gpio.h
+++ b/arch/powerpc/include/asm/gpio.h
@@ -1,53 +1,4 @@
-/*
- * Generic GPIO API implementation for PowerPC.
- *
- * Copyright (c) 2007-2008 MontaVista Software, Inc.
- *
- * Author: Anton Vorontsov <[email protected]>
- *
- * 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_POWERPC_GPIO_H
-#define __ASM_POWERPC_GPIO_H
-
-#include <linux/errno.h>
-#include <asm-generic/gpio.h>
-
-#ifdef CONFIG_GPIOLIB
-
-/*
- * We don't (yet) implement inlined/rapid versions for on-chip gpios.
- * 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);
-}
-
-static inline int gpio_to_irq(unsigned int gpio)
-{
- return __gpio_to_irq(gpio);
-}
-
-static inline int irq_to_gpio(unsigned int irq)
-{
- return -EINVAL;
-}
-
-#endif /* CONFIG_GPIOLIB */
-
-#endif /* __ASM_POWERPC_GPIO_H */
+#ifndef __LINUX_GPIO_H
+#warning Include linux/gpio.h instead of asm/gpio.h
+#include <linux/gpio.h>
+#endif
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 3c8db65..f15181d 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -12,6 +12,7 @@ config SUPERH
select HAVE_DMA_ATTRS
select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
+ select ARCH_HAVE_CUSTOM_GPIO_H
select ARCH_HAVE_NMI_SAFE_CMPXCHG if (GUSA_RB || CPU_SH4A)
select PERF_USE_VMALLOC
select HAVE_KERNEL_GZIP
diff --git a/arch/sparc/include/asm/gpio.h b/arch/sparc/include/asm/gpio.h
index a0e3ac0..b3799d8 100644
--- a/arch/sparc/include/asm/gpio.h
+++ b/arch/sparc/include/asm/gpio.h
@@ -1,36 +1,4 @@
-#ifndef __ASM_SPARC_GPIO_H
-#define __ASM_SPARC_GPIO_H
-
-#include <linux/errno.h>
-#include <asm-generic/gpio.h>
-
-#ifdef CONFIG_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);
-}
-
-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 /* __ASM_SPARC_GPIO_H */
+#ifndef __LINUX_GPIO_H
+#warning Include linux/gpio.h instead of asm/gpio.h
+#include <linux/gpio.h>
+#endif
diff --git a/arch/unicore32/Kconfig b/arch/unicore32/Kconfig
index eeb8054..7ff6d10 100644
--- a/arch/unicore32/Kconfig
+++ b/arch/unicore32/Kconfig
@@ -8,6 +8,7 @@ config UNICORE32
select HAVE_KERNEL_BZIP2
select HAVE_KERNEL_LZO
select HAVE_KERNEL_LZMA
+ select ARCH_HAVE_CUSTOM_GPIO_H
select GENERIC_FIND_FIRST_BIT
select GENERIC_IRQ_PROBE
select GENERIC_IRQ_SHOW
diff --git a/arch/x86/include/asm/gpio.h b/arch/x86/include/asm/gpio.h
index 91d915a..b3799d8 100644
--- a/arch/x86/include/asm/gpio.h
+++ b/arch/x86/include/asm/gpio.h
@@ -1,53 +1,4 @@
-/*
- * Generic GPIO API implementation for x86.
- *
- * Derived from the generic GPIO API for powerpc:
- *
- * Copyright (c) 2007-2008 MontaVista Software, Inc.
- *
- * Author: Anton Vorontsov <[email protected]>
- *
- * 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_X86_GPIO_H
-#define _ASM_X86_GPIO_H
-
-#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);
-}
-
-static inline int gpio_to_irq(unsigned int gpio)
-{
- return __gpio_to_irq(gpio);
-}
-
-static inline int irq_to_gpio(unsigned int irq)
-{
- return -EINVAL;
-}
-
-#endif /* CONFIG_GPIOLIB */
-
-#endif /* _ASM_X86_GPIO_H */
+#ifndef __LINUX_GPIO_H
+#warning Include linux/gpio.h instead of asm/gpio.h
+#include <linux/gpio.h>
+#endif
diff --git a/arch/xtensa/include/asm/gpio.h b/arch/xtensa/include/asm/gpio.h
index a8c9fc4..b3799d8 100644
--- a/arch/xtensa/include/asm/gpio.h
+++ b/arch/xtensa/include/asm/gpio.h
@@ -1,56 +1,4 @@
-/*
- * Generic GPIO API implementation for xtensa.
- *
- * Stolen from x86, which is derived from the generic GPIO API for powerpc:
- *
- * Copyright (c) 2007-2008 MontaVista Software, Inc.
- *
- * Author: Anton Vorontsov <[email protected]>
- *
- * 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_XTENSA_GPIO_H
-#define _ASM_XTENSA_GPIO_H
-
-#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);
-}
-
-static inline int gpio_to_irq(unsigned int gpio)
-{
- return __gpio_to_irq(gpio);
-}
-
-/*
- * Not implemented, yet.
- */
-static inline int irq_to_gpio(unsigned int irq)
-{
- return -EINVAL;
-}
-
-#endif /* CONFIG_GPIOLIB */
-
-#endif /* _ASM_XTENSA_GPIO_H */
+#ifndef __LINUX_GPIO_H
+#warning Include linux/gpio.h instead of asm/gpio.h
+#include <linux/gpio.h>
+#endif
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index d0c4118..81befc0 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -2,6 +2,14 @@
# GPIO infrastructure and drivers
#
+config ARCH_HAVE_CUSTOM_GPIO_H
+ bool
+ help
+ Selecting this config option from the architecture Kconfig allows
+ the architecture to provide a custom asm/gpio.h implementation
+ overriding the default implementations. New uses of this are
+ strongly discouraged.
+
config ARCH_WANT_OPTIONAL_GPIOLIB
bool
help
diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index 38ac48b..3149f68 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -1,6 +1,8 @@
#ifndef __LINUX_GPIO_H
#define __LINUX_GPIO_H
+#include <linux/errno.h>
+
/* see Documentation/gpio.txt */
/* make these flag values available regardless of GPIO kconfig options */
@@ -27,7 +29,39 @@ struct gpio {
};
#ifdef CONFIG_GENERIC_GPIO
+
+#ifdef CONFIG_ARCH_HAVE_CUSTOM_GPIO_H
#include <asm/gpio.h>
+#else
+
+#include <asm-generic/gpio.h>
+
+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);
+}
+
+static inline int gpio_to_irq(unsigned int gpio)
+{
+ return __gpio_to_irq(gpio);
+}
+
+static inline int irq_to_gpio(unsigned int irq)
+{
+ return -EINVAL;
+}
+
+#endif
#else
--
1.7.9.rc1
On Sat, Feb 04, 2012 at 03:54:39PM +0000, Mark Brown wrote:
> Rather than requiring architectures that use gpiolib but don't have any
> need to define anything custom to copy an asm/gpio.h provide a Kconfig
> symbol which architectures must select in order to include gpio.h and
> for other architectures just provide the trivial implementation directly.
Hi Mark.
There is an even simpler solution.
For each arch that uses asm-generic/gpio.h add a line
to arch/$ARCH/include/asm/Kbuild like this:
generic-y += gpio.h
This will then make this arch pick up the asm-generic version when
you do #include <asm/gpio.h>.
And you avoid the kconfig games.
iFor the archs which require their own asm/gpio.h file - just
add it to the asm/ dir - and do not add the generic-y assignment.
Sam
On Sat, Feb 04, 2012 at 06:06:32PM +0100, Sam Ravnborg wrote:
> There is an even simpler solution.
> For each arch that uses asm-generic/gpio.h add a line
> to arch/$ARCH/include/asm/Kbuild like this:
> generic-y += gpio.h
> This will then make this arch pick up the asm-generic version when
> you do #include <asm/gpio.h>.
> And you avoid the kconfig games.
Hrm, that would work but it does mean we still need to go round and
manually enable GPIO support on all architectures which is what I had
been trying to get away from. It is a lot simpler though so it should
be much easier to persuade the architecture maintainers to do that.
On Sat, Feb 04, 2012 at 06:06:32PM +0100, Sam Ravnborg wrote:
> On Sat, Feb 04, 2012 at 03:54:39PM +0000, Mark Brown wrote:
> > Rather than requiring architectures that use gpiolib but don't have any
> > need to define anything custom to copy an asm/gpio.h provide a Kconfig
> > symbol which architectures must select in order to include gpio.h and
> > for other architectures just provide the trivial implementation directly.
>
> Hi Mark.
>
> There is an even simpler solution.
>
> For each arch that uses asm-generic/gpio.h add a line
> to arch/$ARCH/include/asm/Kbuild like this:
>
>
> generic-y += gpio.h
>
> This will then make this arch pick up the asm-generic version when
> you do #include <asm/gpio.h>.
You're assuming that asm-generic/gpio.h was invented to be a replacement
for an architecture asm/gpio.h. Unfortunately, things aren't that
simple.
It would have been a lot better if asm-generic/gpio.h was tacked on the
bottom of linux/gpio.h - because that's what it really is. It's core
code features, not platform stuff.
What's platform specific about asm/gpio.h is the number of GPIOs in
the system, and whether it wants to intercept the gpio_xxx() functions
to provide fast access to on-chip GPIOs.
What I'd suggest is moving asm-generic/gpio.h to linux/gpiolib.h, and
making asm-generic/gpio.h include that as a patch until stuff is fixed
for its new location. That should result in a proper asm-generic/gpio.h
being:
/* The trivial gpiolib dispatchers */
#define gpio_get_value __gpio_get_value
#define gpio_set_value __gpio_set_value
#define gpio_cansleep __gpio_cansleep
#define gpio_to_irq __gpio_to_irq
and nothing else.
Alternatively, instead of linux/gpiolib.h, put it in linux/gpio.h instead,
but that gets more icky because of the mess of asm/gpio.h includes (which
I've been banging on for years about in ARM patches and they're _still_
coming.)
On Sat, Feb 04, 2012 at 05:41:15PM +0000, Russell King - ARM Linux wrote:
> What's platform specific about asm/gpio.h is the number of GPIOs in
> the system, and whether it wants to intercept the gpio_xxx() functions
> to provide fast access to on-chip GPIOs.
Plus the fact that it might be a completely non-standard API, and might
totally override the gpiolib implementation.
> What I'd suggest is moving asm-generic/gpio.h to linux/gpiolib.h, and
> making asm-generic/gpio.h include that as a patch until stuff is fixed
> for its new location. That should result in a proper asm-generic/gpio.h
> being:
> Alternatively, instead of linux/gpiolib.h, put it in linux/gpio.h instead,
> but that gets more icky because of the mess of asm/gpio.h includes (which
> I've been banging on for years about in ARM patches and they're _still_
> coming.)
Yeah, though it is a bit neater if it's all in gpio.h and everyone is
using gpiolib. Perhaps something like the warnings I added on inclusion
of asm/gpio.h without linux/gpio.h would help, though I certainly
wouldn't expect it to solve anything.
On Mon, 16 Apr 2012 09:15:32 +0100, Mark Brown <[email protected]> wrote:
> On Mon, Apr 16, 2012 at 09:21:58AM +0200, Linus Walleij wrote:
>
> > This looks good but I think we need to page the alpha, ia64, m68k, microblaze,
> > openrisc etc subarch maintainers on this patch so they have their say.
>
> That's why I CCed linux-arch, to get all the architecture maintainers
> included. vger would get upset if I CCed everyone individually.
Meh; it's been long enough. I'll build the major ones and then throw it into linux-next.
g.
--
Grant Likely, B.Sc, P.Eng.
Secret Lab Technologies, Ltd.