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>
Gregory Bean