1# 2# GPIO infrastructure and expanders 3# 4 5config ARCH_WANT_OPTIONAL_GPIOLIB 6 bool 7 help 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. 14 15config ARCH_REQUIRE_GPIOLIB 16 bool 17 select GPIOLIB 18 help 19 Platforms select gpiolib if they use this infrastructure 20 for all their GPIOs, usually starting with ones integrated 21 into SOC processors. 22 Selecting this from the architecture code will cause the gpiolib 23 code to always get built in. 24 25 26 27menuconfig GPIOLIB 28 bool "GPIO Support" 29 depends on ARCH_WANT_OPTIONAL_GPIOLIB || ARCH_REQUIRE_GPIOLIB 30 select GENERIC_GPIO 31 help 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. 35 36 If unsure, say N. 37 38if GPIOLIB 39 40config DEBUG_GPIO 41 bool "Debug GPIO calls" 42 depends on DEBUG_KERNEL 43 help 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. 50 51config GPIO_SYSFS 52 bool "/sys/class/gpio/... (sysfs interface)" 53 depends on SYSFS && EXPERIMENTAL 54 help 55 Say Y here to add a sysfs interface for GPIOs. 56 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. 62 63 Kernel drivers may also request that a particular GPIO be 64 exported to userspace; this can be useful when debugging. 65 66# put expanders in the right section, in alphabetical order 67 68comment "Memory mapped GPIO expanders:" 69 70config GPIO_XILINX 71 bool "Xilinx GPIO support" 72 depends on PPC_OF 73 help 74 Say yes here to support the Xilinx FPGA GPIO device 75 76comment "I2C GPIO expanders:" 77 78config GPIO_MAX732X 79 tristate "MAX7319, MAX7320-7327 I2C Port Expanders" 80 depends on I2C 81 help 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 86 below: 87 88 8 bits: max7319 (8I), max7320 (8O), max7321 (8P), 89 max7322 (4I4O), max7323 (4P4O) 90 91 16 bits: max7324 (8I8O), max7325 (8P8O), 92 max7326 (4I12O), max7327 (4P12O) 93 94 Board setup code must specify the model to use, and the start 95 number for these GPIOs. 96 97config GPIO_PCA953X 98 tristate "PCA953x, PCA955x, TCA64xx, and MAX7310 I/O ports" 99 depends on I2C 100 help 101 Say yes here to provide access to several register-oriented 102 SMBus I/O expanders, made mostly by NXP or TI. Compatible 103 models include: 104 105 4 bits: pca9536, pca9537 106 107 8 bits: max7310, pca9534, pca9538, pca9554, pca9557, 108 tca6408 109 110 16 bits: pca9535, pca9539, pca9555, tca6416 111 112 This driver can also be built as a module. If so, the module 113 will be called pca953x. 114 115config GPIO_PCF857X 116 tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders" 117 depends on I2C 118 help 119 Say yes here to provide access to most "quasi-bidirectional" I2C 120 GPIO expanders used for additional digital outputs or inputs. 121 Most of these parts are from NXP, though TI is a second source for 122 some of them. Compatible models include: 123 124 8 bits: pcf8574, pcf8574a, pca8574, pca8574a, 125 pca9670, pca9672, pca9674, pca9674a, 126 max7328, max7329 127 128 16 bits: pcf8575, pcf8575c, pca8575, 129 pca9671, pca9673, pca9675 130 131 Your board setup code will need to declare the expanders in 132 use, and assign numbers to the GPIOs they expose. Those GPIOs 133 can then be used from drivers and other kernel code, just like 134 other GPIOs, but only accessible from task contexts. 135 136 This driver provides an in-kernel interface to those GPIOs using 137 platform-neutral GPIO calls. 138 139config GPIO_TWL4030 140 tristate "TWL4030, TWL5030, and TPS659x0 GPIOs" 141 depends on TWL4030_CORE 142 help 143 Say yes here to access the GPIO signals of various multi-function 144 power management chips from Texas Instruments. 145 146comment "PCI GPIO expanders:" 147 148config GPIO_BT8XX 149 tristate "BT8XX GPIO abuser" 150 depends on PCI && VIDEO_BT848=n 151 help 152 The BT8xx frame grabber chip has 24 GPIO pins than can be abused 153 as a cheap PCI GPIO card. 154 155 This chip can be found on Miro, Hauppauge and STB TV-cards. 156 157 The card needs to be physically altered for using it as a 158 GPIO card. For more information on how to build a GPIO card 159 from a BT8xx TV card, see the documentation file at 160 Documentation/bt8xxgpio.txt 161 162 If unsure, say N. 163 164comment "SPI GPIO expanders:" 165 166config GPIO_MAX7301 167 tristate "Maxim MAX7301 GPIO expander" 168 depends on SPI_MASTER 169 help 170 gpio driver for Maxim MAX7301 SPI GPIO expander. 171 172config GPIO_MCP23S08 173 tristate "Microchip MCP23S08 I/O expander" 174 depends on SPI_MASTER 175 help 176 SPI driver for Microchip MCP23S08 I/O expander. This provides 177 a GPIO interface supporting inputs and outputs. 178 179endif 180