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 The checks help ensure that GPIOs have been properly initialized
46 before they are used and that sleeping calls aren not made from
47 nonsleeping 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 "Xilinx GPIO support"
74 Say yes here to support the Xilinx FPGA GPIO device
76 comment "I2C GPIO expanders:"
79 tristate "MAX7319, MAX7320-7327 I2C Port Expanders"
82 Say yes here to support the MAX7319, MAX7320-7327 series of I2C
83 Port Expanders. Each IO port on these chips has a fixed role of
84 Input (designated by 'I'), Push-Pull Output ('O'), or Open-Drain
85 Input and Output (designed by 'P'). The combinations are listed
88 8 bits: max7319 (8I), max7320 (8O), max7321 (8P),
89 max7322 (4I4O), max7323 (4P4O)
91 16 bits: max7324 (8I8O), max7325 (8P8O),
92 max7326 (4I12O), max7327 (4P12O)
94 Board setup code must specify the model to use, and the start
95 number for these GPIOs.
98 tristate "PCA953x, PCA955x, and MAX7310 I/O ports"
101 Say yes here to provide access to several register-oriented
102 SMBus I/O expanders, made mostly by NXP or TI. Compatible
105 4 bits: pca9536, pca9537
107 8 bits: max7310, pca9534, pca9538, pca9554, pca9557
109 16 bits: pca9535, pca9539, pca9555
111 This driver can also be built as a module. If so, the module
112 will be called pca953x.
115 tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders"
118 Say yes here to provide access to most "quasi-bidirectional" I2C
119 GPIO expanders used for additional digital outputs or inputs.
120 Most of these parts are from NXP, though TI is a second source for
121 some of them. Compatible models include:
123 8 bits: pcf8574, pcf8574a, pca8574, pca8574a,
124 pca9670, pca9672, pca9674, pca9674a,
127 16 bits: pcf8575, pcf8575c, pca8575,
128 pca9671, pca9673, pca9675
130 Your board setup code will need to declare the expanders in
131 use, and assign numbers to the GPIOs they expose. Those GPIOs
132 can then be used from drivers and other kernel code, just like
133 other GPIOs, but only accessible from task contexts.
135 This driver provides an in-kernel interface to those GPIOs using
136 platform-neutral GPIO calls.
139 tristate "TWL4030, TWL5030, and TPS659x0 GPIOs"
140 depends on TWL4030_CORE
142 Say yes here to access the GPIO signals of various multi-function
143 power management chips from Texas Instruments.
145 comment "PCI GPIO expanders:"
148 tristate "BT8XX GPIO abuser"
149 depends on PCI && VIDEO_BT848=n
151 The BT8xx frame grabber chip has 24 GPIO pins than can be abused
152 as a cheap PCI GPIO card.
154 This chip can be found on Miro, Hauppauge and STB TV-cards.
156 The card needs to be physically altered for using it as a
157 GPIO card. For more information on how to build a GPIO card
158 from a BT8xx TV card, see the documentation file at
159 Documentation/bt8xxgpio.txt
163 comment "SPI GPIO expanders:"
166 tristate "Maxim MAX7301 GPIO expander"
167 depends on SPI_MASTER
169 gpio driver for Maxim MAX7301 SPI GPIO expander.
172 tristate "Microchip MCP23S08 I/O expander"
173 depends on SPI_MASTER
175 SPI driver for Microchip MCP23S08 I/O expander. This provides
176 a GPIO interface supporting inputs and outputs.