Le Thursday 09 April 2009 19:49:22 Manuel Lauss, vous avez écrit : > The current approach is not sufficiently generic for my needs: > I want to use generic functions which deal with the GPIO1 and GPIO2 > blocks, but don't want the default gpio numberspace as imposed by the > databooks; instead I also want the option to register gpio_chips for > my board with a custom gpio namespace. > > To address this, the following changes are made to the alchemy gpio > code: > > - create linux-gpio-system compatible functions which deal with > manipulating the GPIO1/2 blocks. These functions are universally > useful. > - gpiolib is optional > > If CONFIG_GPIOLIB is not enabled, provide the equivalent functions > by directly inlining the GPIO1/2 functions. Obviously this limits > the usable GPIOs to those present on the Alchemy chip. GPIOs can > be accessed as documented in the datasheets (GPIO0-31 and 200-215). > > If CONFIG_GPIOLIB is selected, by default 2 gpio_chips for GPIO1/2 > are registered, and the inlines are no longer usable. The number- > space is as is documented in the datasheets. > > However this is not yet flexible enough for my uses. My Alchemy > systems have a documented "external" gpio interface (fixed number- > space) and can support a variety of baseboards, some of which are > equipped with I2C gpio expanders. I want to be able to provide > the default 16 GPIOs of the CPU board numbered as 0..15 and also > support gpio expanders, if present, starting as gpio16. > > To achieve this, a new Kconfig symbol for Alchemy is introduced, > CONFIG_ALCHEMY_GPIO_INDIRECT, which boards can enable to signal > that they are not okay with the default Alchemy GPIO functions AND > numberspace and want to provide their own. This also works for both > CONFIG_GPIOLIB=y and CONFIG_GPIOLIB=n. When this config symbol is > selected, boards must provide their own gpio_* functions; either in > a custom gpio.h header (in board include directory) or with gpio_chips. > > To make the board-specific inlined gpio functions work, the MIPS > Makefile must be changed so that the mach-au1x00/gpio.h header is > included _after_ the board headers. > > see arch/mips/include/asm/mach-au1x00/gpio.h for more info. That's fine with me, I do not see obvious breakages for boards that will use the standard GPIO interface. Thanks for your work ! > > Cc: Florian Fainelli <florian@xxxxxxxxxxx> Acked-by: <florian@xxxxxxxxxxx> -- Best regards, Florian Fainelli Email : florian@xxxxxxxxxxx http://openwrt.org -------------------------------
