gpiolib: Allow user-selection
Subsystems (10)
PATCH v3 1/1 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 <[email protected]>
---
This patch should be scheduled for the next kernel feature merge window. This is diffed against current linux-next.
The defconfig patching was removed since the last version of the patch. defconfigs will automatically get updated.
arch/x86/Kconfig +1 -0
@@ -27,6 +27,7 @@ config X86 select HAVE_FTRACE select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64) select HAVE_ARCH_KGDB if !X86_VOYAGER + select ARCH_WANT_OPTIONAL_GPIOLIB if !X86_RDC321X config ARCH_DEFCONFIG string
include/asm-x86/gpio.h +56 -0
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arch/powerpc/Kconfig +1 -0
@@ -113,6 +113,7 @@ config PPC select HAVE_LMB select USE_GENERIC_SMP_HELPERS if SMP select HAVE_OPROFILE + select ARCH_WANT_OPTIONAL_GPIOLIB config EARLY_PRINTK bool
drivers/gpio/Kconfig +29 -4
@@ -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. + + + +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. -menu "GPIO Support" - depends on HAVE_GPIO_LIB +if GPIOLIB config DEBUG_GPIO bool "Debug GPIO calls"
@@ -76,4 +101,4 @@ config GPIO_MCP23S08 SPI driver for Microchip MCP23S08 I/O expander. This provides a GPIO interface supporting inputs and outputs. -endmenu +endif
drivers/gpio/Makefile +1 -1
@@ -2,7 +2,7 @@ ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG -obj-$(CONFIG_HAVE_GPIO_LIB) += gpiolib.o +obj-$(CONFIG_GPIOLIB) += gpiolib.o obj-$(CONFIG_GPIO_MCP23S08) += mcp23s08.o obj-$(CONFIG_GPIO_PCA953X) += pca953x.o
Documentation/gpio.txt +11 -1
@@ -392,11 +392,21 @@ either NULL or the label associated with 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:
arch/arm/Kconfig +4 -4
@@ -262,7 +262,7 @@ config ARCH_EP93XX select ARM_AMBA select ARM_VIC select GENERIC_GPIO - select HAVE_GPIO_LIB + select ARCH_REQUIRE_GPIOLIB help This enables support for the Cirrus EP93xx series of CPUs.
@@ -430,7 +430,7 @@ config ARCH_PXA depends on MMU select ARCH_MTD_XIP select GENERIC_GPIO - select HAVE_GPIO_LIB + select ARCH_REQUIRE_GPIOLIB select GENERIC_TIME select GENERIC_CLOCKEVENTS select TICK_ONESHOT
@@ -461,7 +461,7 @@ config ARCH_SA1100 select GENERIC_TIME select GENERIC_CLOCKEVENTS select TICK_ONESHOT - select HAVE_GPIO_LIB + select ARCH_REQUIRE_GPIOLIB help Support for StrongARM 11x0 based boards.
@@ -501,7 +501,7 @@ config ARCH_DAVINCI config ARCH_OMAP bool "TI OMAP" select GENERIC_GPIO - select HAVE_GPIO_LIB + select ARCH_REQUIRE_GPIOLIB select GENERIC_TIME select GENERIC_CLOCKEVENTS help
arch/avr32/Kconfig +1 -1
@@ -87,7 +87,7 @@ config PLATFORM_AT32AP select SUBARCH_AVR32B select MMU select PERFORMANCE_COUNTERS - select HAVE_GPIO_LIB + select ARCH_REQUIRE_GPIOLIB select GENERIC_ALLOCATOR #
arch/mips/Kconfig +1 -1
@@ -748,7 +748,7 @@ config CSRC_SB1250 config GPIO_TXX9 select GENERIC_GPIO - select HAVE_GPIO_LIB + select ARCH_REQUIRE_GPIOLIB bool config CFE
arch/powerpc/platforms/52xx/Kconfig +1 -1
@@ -47,6 +47,6 @@ config PPC_MPC5200_BUGFIX 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
drivers/Makefile +1 -1
@@ -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/
drivers/i2c/chips/Kconfig +1 -1
@@ -126,7 +126,7 @@ config ISP1301_OMAP 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
drivers/mfd/Kconfig +2 -2
@@ -28,7 +28,7 @@ config MFD_ASIC3 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
@@ -44,7 +44,7 @@ config HTC_PASIC3 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
drivers/of/Kconfig +1 -1
@@ -4,7 +4,7 @@ config OF_DEVICE config OF_GPIO def_bool y - depends on OF && PPC_OF && HAVE_GPIO_LIB + depends on OF && PPC_OF && GPIOLIB help OpenFirmware GPIO accessors
include/asm-generic/gpio.h +1 -1
@@ -3,7 +3,7 @@#include <linux/types.h> -#ifdef CONFIG_HAVE_GPIO_LIB +#ifdef CONFIG_GPIOLIB #include <linux/compiler.h>
include/asm-mips/mach-generic/gpio.h +1 -1
@@ -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
include/asm-powerpc/gpio.h +2 -2
@@ -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 @@ static inline int irq_to_gpio(unsigned ireturn -EINVAL ; } -#endif /* CONFIG_HAVE_GPIO_LIB */ +#endif /* CONFIG_GPIOLIB */ #endif /* __ASM_POWERPC_GPIO_H */
arch/powerpc/sysdev/qe_lib/Kconfig +1 -1
@@ -29,7 +29,7 @@ config QE_GPIO 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.
Signature · 1 line
Greetings Michael.