projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| a9c5fff5 DB |
1 | # |
| 2 | # GPIO infrastructure and expanders | |
| 3 | # | |
| 4 | ||
| 5 | config HAVE_GPIO_LIB | |
| 6 | bool | |
| 7 | help | |
| 8 | Platforms select gpiolib if they use this infrastructure | |
| 9 | for all their GPIOs, usually starting with ones integrated | |
| 10 | into SOC processors. | |
| 11 | ||
| 12 | menu "GPIO Support" | |
| 13 | depends on HAVE_GPIO_LIB | |
| 14 | ||
| 15 | config DEBUG_GPIO | |
| 16 | bool "Debug GPIO calls" | |
| 17 | depends on DEBUG_KERNEL | |
| 18 | help | |
| 19 | Say Y here to add some extra checks and diagnostics to GPIO calls. | |
| 20 | The checks help ensure that GPIOs have been properly initialized | |
| 21 | before they are used and that sleeping calls aren not made from | |
| 22 | nonsleeping contexts. They can make bitbanged serial protocols | |
| 23 | slower. The diagnostics help catch the type of setup errors | |
| 24 | that are most common when setting up new platforms or boards. | |
| 25 | ||
| 26 | # put expanders in the right section, in alphabetical order | |
| 27 | ||
| 28 | comment "I2C GPIO expanders:" | |
| 29 | ||
| 15fae37d DB |
30 | config GPIO_PCF857X |
| 31 | tristate "PCF857x, PCA857x, and PCA967x I2C GPIO expanders" | |
| 32 | depends on I2C | |
| 33 | help | |
| 34 | Say yes here to provide access to most "quasi-bidirectional" I2C | |
| 35 | GPIO expanders used for additional digital outputs or inputs. | |
| 36 | Most of these parts are from NXP, though TI is a second source for | |
| 37 | some of them. Compatible models include: | |
| 38 | ||
| 39 | 8 bits: pcf8574, pcf8574a, pca8574, pca8574a, | |
| 40 | pca9670, pca9672, pca9674, pca9674a | |
| 41 | ||
| 42 | 16 bits: pcf8575, pcf8575c, pca8575, | |
| 43 | pca9671, pca9673, pca9675 | |
| 44 | ||
| 45 | Your board setup code will need to declare the expanders in | |
| 46 | use, and assign numbers to the GPIOs they expose. Those GPIOs | |
| 47 | can then be used from drivers and other kernel code, just like | |
| 48 | other GPIOs, but only accessible from task contexts. | |
| 49 | ||
| 50 | This driver provides an in-kernel interface to those GPIOs using | |
| 51 | platform-neutral GPIO calls. | |
| 52 | ||
| a9c5fff5 DB |
53 | comment "SPI GPIO expanders:" |
| 54 | ||
| e58b9e27 DB |
55 | config GPIO_MCP23S08 |
| 56 | tristate "Microchip MCP23S08 I/O expander" | |
| 57 | depends on SPI_MASTER | |
| 58 | help | |
| 59 | SPI driver for Microchip MCP23S08 I/O expander. This provides | |
| 60 | a GPIO interface supporting inputs and outputs. | |
| 61 | ||
| a9c5fff5 | 62 | endmenu |