• Philipp Zabel's avatar
    regulator/max1586: fix V3 gain calculation integer overflow · c8f1e502
    Philipp Zabel authored
    On Thu, May 28, 2009 at 10:59 AM, Mark Brown <broonie@opensource.wolfsonmicro.com> wrote:
    > On Thu, May 28, 2009 at 07:15:16AM +0200, Philipp Zabel wrote:
    >> The V3 regulator can be configured with an external resistor
    >> connected to the feedback pin (R24 in the data sheet) to
    >> increase the voltage range.
    >>
    >> For example, hx4700 has R24 = 3.32 kOhm to achieve a maximum
    >> V3 voltage of 1.55 V which is needed for 624 MHz CPU frequency.
    >>
    >> Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
    >
    > Looks good.
    >
    > Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
    
    Thanks, but it turns out I hit a 32 bit integer overflow in
    the gain calculation. I'd like to mend that with the following
    patch. Now max_uV could be increased up to 4.294 V, enough to
    charge LiPo cells.
    Signed-off-by: default avatarPhilipp Zabel <philipp.zabel@gmail.com>
    Acked-by: default avatarRobert Jarzmik <robert.jarzmik@free.fr>
    Signed-off-by: default avatarLiam Girdwood <lrg@slimlogic.co.uk>
    c8f1e502
max1586.c 7.2 KB