• Janusz Krzysztofik's avatar
    ARM: OMAP1: ams-delta: initialize latch2 pins to safe values · 1464d031
    Janusz Krzysztofik authored
    Latch2 pins control a number of on-board devices, namely LCD, NAND,
    MODEM and CODEC.  Those pins used to be initialized with safe values
    from init_machine before that operation was:
    1) moved to late_initcall in preparation for conversion of latch2 to
    GPIO device - see commit f7519d8c ("ARM: OMAP1: ams-delta: register
    latch dependent devices later"),
    2) replaced with non-atomic initialization performed by means of
    gpio_request_array() - see commit 937eb4bb ("ARM: OMAP1: ams-delta:
    convert latches to basic_mmio_gpio"),
    3) made completely asynchronous by delegation of GPIO request
    operations performed on subsets of pins to respective device drivers in
    subsequent commits.
    
    One visible negative result of that disintegration was corrupt keyboard
    data reported by serio driver, recently fixed by commit 41f8fee3
    ("ARM: OMAP1: ams-delta: Hog "keybrd_dataout" GPIO pin").
    
    Moreover, initialization of LATCH2_PIN_MODEM_CODEC still performed with
    ams_delta_latch2_write() wrapper from late_init() is now done on not
    requested GPIO pin.
    
    Reintroduce atomic initialization of latch2 pins at machine_init to
    prevent from random values potentially corrupting NAND data or maybe
    even destroing other hardware.  Also take care of MODEM/CODEC related
    pins so MODEM device probe succeeds even if latch2 GPIO device or
    dependent regulator is not ready and CODEC can be reached over the
    MODEM even if audio driver doesn't take control over
    LATCH2_PIN_MODEM_CODEC.
    
    Once done, remove the no longer needed GPIO based implementation of
    ams_delta_latch_write() and its frontend macro.
    Signed-off-by: default avatarJanusz Krzysztofik <jmkrzyszt@gmail.com>
    Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
    [tony@atomide.com: updated for the header location to remove dependency]
    Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
    1464d031
board-ams-delta.h 2.57 KB