regulator/max1586: fix V3 gain calculation integer overflow
authorPhilipp Zabel <philipp.zabel@gmail.com>
Thu, 28 May 2009 19:00:03 +0000 (21:00 +0200)
committerLiam Girdwood <lrg@slimlogic.co.uk>
Mon, 15 Jun 2009 10:18:27 +0000 (11:18 +0100)
commitc8f1e5025ca2fa8e6e037451f3d271e66745a19b
tree22d0cc384cee47f639163daa15a1d6dff91da1b4
parentb110a8fb242bc34e4b7686252899ce0fca956e2c
regulator/max1586: fix V3 gain calculation integer overflow

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: Philipp Zabel <philipp.zabel@gmail.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
drivers/regulator/max1586.c