• Roger Quadros's avatar
    can: c_can: use regmap_update_bits() to modify RAMINIT register · 47e3485a
    Roger Quadros authored
    use of regmap_read() and regmap_write() in c_can_hw_raminit_syscon()
    is not safe as the RAMINIT register can be shared between different drivers
    at least for TI SoCs.
    
    To make the modification atomic we switch to using regmap_update_bits().
    
    regmap_update_bits() skips writing to the register if it's read content is the
    same as what is going to be written. This causes an issue for us when we
    need to clear the DONE bit with the initial condition START:0, DONE:1 as
    DONE bit must be written with 1 to clear it.
    
    So we defer the clearing of DONE bit to later when we set the START bit.
    There we are sure that START bit is changed from 0 to 1 so the write of
    1 to already set DONE bit will happen.
    Signed-off-by: default avatarRoger Quadros <rogerq@ti.com>
    Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
    47e3485a
c_can_platform.c 12.5 KB