2 # GPIO infrastructure and expanders
5 config ARCH_WANT_OPTIONAL_GPIOLIB
8 Select this config option from the architecture Kconfig, if
9 it is possible to use gpiolib on the architecture, but let the
10 user decide whether to actually build it or not.
11 Select this instead of ARCH_REQUIRE_GPIOLIB, if your architecture does
12 not depend on GPIOs being available, but rather let the user
13 decide whether he needs it or not.
15 config ARCH_REQUIRE_GPIOLIB
19 Platforms select gpiolib if they use this infrastructure
20 for all their GPIOs, usually starting with ones integrated
22 Selecting this from the architecture code will cause the gpiolib
23 code to always get built in.
29 depends on ARCH_WANT_OPTIONAL_GPIOLIB || ARCH_REQUIRE_GPIOLIB
32 This enables GPIO support through the generic GPIO library.
33 You only need to enable this, if you also want to enable
34 one or more of the GPIO expansion card drivers below.
41 bool "Debug GPIO calls"
42 depends on DEBUG_KERNEL
44 Say Y here to add some extra checks and diagnostics to GPIO calls.
45 These checks help ensure that GPIOs have been properly initialized
46 before they are used, and that sleeping calls are not made from
47 non-sleeping contexts. They can make bitbanged serial protocols
48 slower. The diagnostics help catch the type of setup errors
49 that are most common when setting up new platforms or boards.
52 bool "/sys/class/gpio/... (sysfs interface)"
53 depends on SYSFS && EXPERIMENTAL
55 Say Y here to add a sysfs interface for GPIOs.
57 This is mostly useful to work around omissions in a system's
58 kernel support. Those are common in custom and semicustom
59 hardware assembled using standard kernels with a minimum of
60 custom patches. In those cases, userspace code may import
61 a given GPIO from the kernel, if no kernel driver requested it.
63 Kernel drivers may also request that a particular GPIO be
64 exported to userspace; this can be useful when debugging.
66 # put expanders in the right section, in alphabetical order
68 comment "Memory mapped GPIO expanders:"
71 bool "PrimeCell PL061 GPIO support"
74 Say yes here to support the PrimeCell PL061 GPIO device
77 bool "Xilinx GPIO support"
78 depends on PPC_OF || MICROBLAZE
80 Say yes here to support the Xilinx FPGA GPIO device
83 tristate "NEC VR4100 series General-purpose I/O Uint support"
86 Say yes here to support the NEC VR4100 series General-purpose I/O Uint
88 comment "I2C GPIO expanders:"
91 tristate "MAX7319, MAX7320-7327 I2C Port Expanders"
94 Say yes here to support the MAX7319, MAX7320-7327 series of I2C
95 Port Expanders. Each IO port on these chips has a fixed role of
96 Input (designated by 'I'), Push-Pull Output ('O'), or Open-Drain
97 Input and Output (designed by 'P'). The combinations are listed
100 8 bits: max7319 (8I), max7320 (8O), max7321 (8P),
101 max7322 (4I4O), max7323 (4P4O)
103 16 bits: max7324 (8I8O), max7325 (8P8O),
104 max7326 (4I12O), max7327 (4P12O)
106 Board setup code must specify the model to use, and the start
107 number for these GPIOs.
110 tristate "PCA953x, PCA955x, TCA64xx, and MAX7310 I/O ports"
113 Say yes here to provide access to several register-oriented
114 SMBus I/O expanders, made mostly by NXP or TI. Compatible
117 4 bits: pca9536, pca9537
119 8 bits: max7310, pca9534, pca9538, pca9554, pca9557,
122 16 bits: pca9535, pca9539, pca9555, tca6416
124 This driver can also be built as a module. If so, the module
125 will be called pca953x.
128 tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders"
131 Say yes here to provide access to most "quasi-bidirectional" I2C
132 GPIO expanders used for additional digital outputs or inputs.
133 Most of these parts are from NXP, though TI is a second source for
134 some of them. Compatible models include:
136 8 bits: pcf8574, pcf8574a, pca8574, pca8574a,
137 pca9670, pca9672, pca9674, pca9674a,
140 16 bits: pcf8575, pcf8575c, pca8575,
141 pca9671, pca9673, pca9675
143 Your board setup code will need to declare the expanders in
144 use, and assign numbers to the GPIOs they expose. Those GPIOs
145 can then be used from drivers and other kernel code, just like
146 other GPIOs, but only accessible from task contexts.
148 This driver provides an in-kernel interface to those GPIOs using
149 platform-neutral GPIO calls.
152 tristate "TWL4030, TWL5030, and TPS659x0 GPIOs"
153 depends on TWL4030_CORE
155 Say yes here to access the GPIO signals of various multi-function
156 power management chips from Texas Instruments.
158 comment "PCI GPIO expanders:"
161 tristate "BT8XX GPIO abuser"
162 depends on PCI && VIDEO_BT848=n
164 The BT8xx frame grabber chip has 24 GPIO pins than can be abused
165 as a cheap PCI GPIO card.
167 This chip can be found on Miro, Hauppauge and STB TV-cards.
169 The card needs to be physically altered for using it as a
170 GPIO card. For more information on how to build a GPIO card
171 from a BT8xx TV card, see the documentation file at
172 Documentation/bt8xxgpio.txt
176 comment "SPI GPIO expanders:"
179 tristate "Maxim MAX7301 GPIO expander"
180 depends on SPI_MASTER
182 gpio driver for Maxim MAX7301 SPI GPIO expander.
185 tristate "Microchip MCP23S08 I/O expander"
186 depends on SPI_MASTER
188 SPI driver for Microchip MCP23S08 I/O expander. This provides
189 a GPIO interface supporting inputs and outputs.