164 lines
5.1 KiB
Plaintext
164 lines
5.1 KiB
Plaintext
#
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# GPIO infrastructure and expanders
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#
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config ARCH_WANT_OPTIONAL_GPIOLIB
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bool
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help
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Select this config option from the architecture Kconfig, if
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it is possible to use gpiolib on the architecture, but let the
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user decide whether to actually build it or not.
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Select this instead of ARCH_REQUIRE_GPIOLIB, if your architecture does
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not depend on GPIOs being available, but rather let the user
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decide whether he needs it or not.
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config ARCH_REQUIRE_GPIOLIB
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bool
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select GPIOLIB
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help
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Platforms select gpiolib if they use this infrastructure
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for all their GPIOs, usually starting with ones integrated
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into SOC processors.
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Selecting this from the architecture code will cause the gpiolib
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code to always get built in.
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menuconfig GPIOLIB
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bool "GPIO Support"
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depends on ARCH_WANT_OPTIONAL_GPIOLIB || ARCH_REQUIRE_GPIOLIB
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select GENERIC_GPIO
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help
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This enables GPIO support through the generic GPIO library.
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You only need to enable this, if you also want to enable
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one or more of the GPIO expansion card drivers below.
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If unsure, say N.
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if GPIOLIB
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config DEBUG_GPIO
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bool "Debug GPIO calls"
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depends on DEBUG_KERNEL
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help
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Say Y here to add some extra checks and diagnostics to GPIO calls.
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The checks help ensure that GPIOs have been properly initialized
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before they are used and that sleeping calls aren not made from
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nonsleeping contexts. They can make bitbanged serial protocols
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slower. The diagnostics help catch the type of setup errors
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that are most common when setting up new platforms or boards.
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config GPIO_SYSFS
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bool "/sys/class/gpio/... (sysfs interface)"
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depends on SYSFS && EXPERIMENTAL
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help
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Say Y here to add a sysfs interface for GPIOs.
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This is mostly useful to work around omissions in a system's
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kernel support. Those are common in custom and semicustom
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hardware assembled using standard kernels with a minimum of
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custom patches. In those cases, userspace code may import
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a given GPIO from the kernel, if no kernel driver requested it.
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Kernel drivers may also request that a particular GPIO be
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exported to userspace; this can be useful when debugging.
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# put expanders in the right section, in alphabetical order
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comment "I2C GPIO expanders:"
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config GPIO_MAX732X
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tristate "MAX7319, MAX7320-7327 I2C Port Expanders"
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depends on I2C
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help
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Say yes here to support the MAX7319, MAX7320-7327 series of I2C
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Port Expanders. Each IO port on these chips has a fixed role of
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Input (designated by 'I'), Push-Pull Output ('O'), or Open-Drain
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Input and Output (designed by 'P'). The combinations are listed
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below:
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8 bits: max7319 (8I), max7320 (8O), max7321 (8P),
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max7322 (4I4O), max7323 (4P4O)
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16 bits: max7324 (8I8O), max7325 (8P8O),
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max7326 (4I12O), max7327 (4P12O)
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Board setup code must specify the model to use, and the start
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number for these GPIOs.
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config GPIO_PCA953X
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tristate "PCA953x, PCA955x, and MAX7310 I/O ports"
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depends on I2C
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help
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Say yes here to provide access to several register-oriented
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SMBus I/O expanders, made mostly by NXP or TI. Compatible
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models include:
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4 bits: pca9536, pca9537
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8 bits: max7310, pca9534, pca9538, pca9554, pca9557
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16 bits: pca9535, pca9539, pca9555
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This driver can also be built as a module. If so, the module
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will be called pca953x.
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config GPIO_PCF857X
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tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders"
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depends on I2C
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help
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Say yes here to provide access to most "quasi-bidirectional" I2C
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GPIO expanders used for additional digital outputs or inputs.
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Most of these parts are from NXP, though TI is a second source for
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some of them. Compatible models include:
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8 bits: pcf8574, pcf8574a, pca8574, pca8574a,
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pca9670, pca9672, pca9674, pca9674a,
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max7328, max7329
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16 bits: pcf8575, pcf8575c, pca8575,
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pca9671, pca9673, pca9675
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Your board setup code will need to declare the expanders in
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use, and assign numbers to the GPIOs they expose. Those GPIOs
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can then be used from drivers and other kernel code, just like
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other GPIOs, but only accessible from task contexts.
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This driver provides an in-kernel interface to those GPIOs using
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platform-neutral GPIO calls.
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comment "PCI GPIO expanders:"
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config GPIO_BT8XX
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tristate "BT8XX GPIO abuser"
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depends on PCI && VIDEO_BT848=n
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help
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The BT8xx frame grabber chip has 24 GPIO pins than can be abused
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as a cheap PCI GPIO card.
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This chip can be found on Miro, Hauppauge and STB TV-cards.
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The card needs to be physically altered for using it as a
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GPIO card. For more information on how to build a GPIO card
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from a BT8xx TV card, see the documentation file at
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Documentation/bt8xxgpio.txt
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If unsure, say N.
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comment "SPI GPIO expanders:"
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config GPIO_MAX7301
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tristate "Maxim MAX7301 GPIO expander"
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depends on SPI_MASTER
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help
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gpio driver for Maxim MAX7301 SPI GPIO expander.
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config GPIO_MCP23S08
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tristate "Microchip MCP23S08 I/O expander"
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depends on SPI_MASTER
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help
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SPI driver for Microchip MCP23S08 I/O expander. This provides
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a GPIO interface supporting inputs and outputs.
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endif
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