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_PL061 71 bool "PrimeCell PL061 GPIO support" 72 depends on ARM_AMBA 73 help 74 Say yes here to support the PrimeCell PL061 GPIO device 75 76config GPIO_XILINX 77 bool "Xilinx GPIO support" 78 depends on PPC_OF || MICROBLAZE 79 help 80 Say yes here to support the Xilinx FPGA GPIO device 81 82config GPIO_VR41XX 83 tristate "NEC VR4100 series General-purpose I/O Uint support" 84 depends on CPU_VR41XX 85 help 86 Say yes here to support the NEC VR4100 series General-purpose I/O Uint 87 88comment "I2C GPIO expanders:" 89 90config GPIO_MAX732X 91 tristate "MAX7319, MAX7320-7327 I2C Port Expanders" 92 depends on I2C 93 help 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 98 below: 99 100 8 bits: max7319 (8I), max7320 (8O), max7321 (8P), 101 max7322 (4I4O), max7323 (4P4O) 102 103 16 bits: max7324 (8I8O), max7325 (8P8O), 104 max7326 (4I12O), max7327 (4P12O) 105 106 Board setup code must specify the model to use, and the start 107 number for these GPIOs. 108 109config GPIO_PCA953X 110 tristate "PCA953x, PCA955x, TCA64xx, and MAX7310 I/O ports" 111 depends on I2C 112 help 113 Say yes here to provide access to several register-oriented 114 SMBus I/O expanders, made mostly by NXP or TI. Compatible 115 models include: 116 117 4 bits: pca9536, pca9537 118 119 8 bits: max7310, pca9534, pca9538, pca9554, pca9557, 120 tca6408 121 122 16 bits: pca9535, pca9539, pca9555, tca6416 123 124 This driver can also be built as a module. If so, the module 125 will be called pca953x. 126 127config GPIO_PCF857X 128 tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders" 129 depends on I2C 130 help 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: 135 136 8 bits: pcf8574, pcf8574a, pca8574, pca8574a, 137 pca9670, pca9672, pca9674, pca9674a, 138 max7328, max7329 139 140 16 bits: pcf8575, pcf8575c, pca8575, 141 pca9671, pca9673, pca9675 142 143 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. 147 148 This driver provides an in-kernel interface to those GPIOs using 149 platform-neutral GPIO calls. 150 151config GPIO_TWL4030 152 tristate "TWL4030, TWL5030, and TPS659x0 GPIOs" 153 depends on TWL4030_CORE 154 help 155 Say yes here to access the GPIO signals of various multi-function 156 power management chips from Texas Instruments. 157 158comment "PCI GPIO expanders:" 159 160config GPIO_BT8XX 161 tristate "BT8XX GPIO abuser" 162 depends on PCI && VIDEO_BT848=n 163 help 164 The BT8xx frame grabber chip has 24 GPIO pins than can be abused 165 as a cheap PCI GPIO card. 166 167 This chip can be found on Miro, Hauppauge and STB TV-cards. 168 169 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 173 174 If unsure, say N. 175 176comment "SPI GPIO expanders:" 177 178config GPIO_MAX7301 179 tristate "Maxim MAX7301 GPIO expander" 180 depends on SPI_MASTER 181 help 182 gpio driver for Maxim MAX7301 SPI GPIO expander. 183 184config GPIO_MCP23S08 185 tristate "Microchip MCP23S08 I/O expander" 186 depends on SPI_MASTER 187 help 188 SPI driver for Microchip MCP23S08 I/O expander. This provides 189 a GPIO interface supporting inputs and outputs. 190 191endif 192