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path: root/arch/arm/mach-msm/gpiomux-v1.c
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2010-10-06msm: add gpiomux api for gpio multiplex & configuration.Gregory Bean
Add the 'gpiomux' api, which addresses the following shortcomings of existing tlmm api: - gpio power-collapse, which is managed by a peripheral processor on other targets, must be managed by the application processor on the 8x60. - The enable/disable flag of the legacy gpio_tlmm_config api is not applicable on the 8x60, and causes confusion. - The gpio 'direction' bits are meaningless for all func_sel configurations except for generic-gpio mode (func_sel 0), in which case the gpio_direction_* functions should be used. Having these bits in the tlmm api leads to confusion and misuse of the gpiolib api, and they have been removed in gpiomux. - The functional api of the legacy system ran contrary to the typical use-case, which is a single massive configuration at boot. Rather than forcing hundreds of 'config' function calls, the new api allows data to be configured with a single table. gpiomux_get and gpiomux_put are meant to be called automatically when gpio_request and gpio_free are called, giving automatic gpiomux/tlmm control to those drivers/lines with simple power profiles - in the simplest cases, an entry in the gpiomux table and the correct usage of gpiolib is all that is required to get proper gpio power control. Signed-off-by: Gregory Bean <gbean@codeaurora.org> Signed-off-by: Daniel Walker <dwalker@codeaurora.org>