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 82comment "I2C GPIO expanders:" 83 84config GPIO_MAX732X 85 tristate "MAX7319, MAX7320-7327 I2C Port Expanders" 86 depends on I2C 87 help 88 Say yes here to support the MAX7319, MAX7320-7327 series of I2C 89 Port Expanders. Each IO port on these chips has a fixed role of 90 Input (designated by 'I'), Push-Pull Output ('O'), or Open-Drain 91 Input and Output (designed by 'P'). The combinations are listed 92 below: 93 94 8 bits: max7319 (8I), max7320 (8O), max7321 (8P), 95 max7322 (4I4O), max7323 (4P4O) 96 97 16 bits: max7324 (8I8O), max7325 (8P8O), 98 max7326 (4I12O), max7327 (4P12O) 99 100 Board setup code must specify the model to use, and the start 101 number for these GPIOs. 102 103config GPIO_PCA953X 104 tristate "PCA953x, PCA955x, TCA64xx, and MAX7310 I/O ports" 105 depends on I2C 106 help 107 Say yes here to provide access to several register-oriented 108 SMBus I/O expanders, made mostly by NXP or TI. Compatible 109 models include: 110 111 4 bits: pca9536, pca9537 112 113 8 bits: max7310, pca9534, pca9538, pca9554, pca9557, 114 tca6408 115 116 16 bits: pca9535, pca9539, pca9555, tca6416 117 118 This driver can also be built as a module. If so, the module 119 will be called pca953x. 120 121config GPIO_PCF857X 122 tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders" 123 depends on I2C 124 help 125 Say yes here to provide access to most "quasi-bidirectional" I2C 126 GPIO expanders used for additional digital outputs or inputs. 127 Most of these parts are from NXP, though TI is a second source for 128 some of them. Compatible models include: 129 130 8 bits: pcf8574, pcf8574a, pca8574, pca8574a, 131 pca9670, pca9672, pca9674, pca9674a, 132 max7328, max7329 133 134 16 bits: pcf8575, pcf8575c, pca8575, 135 pca9671, pca9673, pca9675 136 137 Your board setup code will need to declare the expanders in 138 use, and assign numbers to the GPIOs they expose. Those GPIOs 139 can then be used from drivers and other kernel code, just like 140 other GPIOs, but only accessible from task contexts. 141 142 This driver provides an in-kernel interface to those GPIOs using 143 platform-neutral GPIO calls. 144 145config GPIO_TWL4030 146 tristate "TWL4030, TWL5030, and TPS659x0 GPIOs" 147 depends on TWL4030_CORE 148 help 149 Say yes here to access the GPIO signals of various multi-function 150 power management chips from Texas Instruments. 151 152comment "PCI GPIO expanders:" 153 154config GPIO_BT8XX 155 tristate "BT8XX GPIO abuser" 156 depends on PCI && VIDEO_BT848=n 157 help 158 The BT8xx frame grabber chip has 24 GPIO pins than can be abused 159 as a cheap PCI GPIO card. 160 161 This chip can be found on Miro, Hauppauge and STB TV-cards. 162 163 The card needs to be physically altered for using it as a 164 GPIO card. For more information on how to build a GPIO card 165 from a BT8xx TV card, see the documentation file at 166 Documentation/bt8xxgpio.txt 167 168 If unsure, say N. 169 170comment "SPI GPIO expanders:" 171 172config GPIO_MAX7301 173 tristate "Maxim MAX7301 GPIO expander" 174 depends on SPI_MASTER 175 help 176 gpio driver for Maxim MAX7301 SPI GPIO expander. 177 178config GPIO_MCP23S08 179 tristate "Microchip MCP23S08 I/O expander" 180 depends on SPI_MASTER 181 help 182 SPI driver for Microchip MCP23S08 I/O expander. This provides 183 a GPIO interface supporting inputs and outputs. 184 185endif 186