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authorPhilipp Zabel <philipp.zabel@gmail.com>2009-05-28 23:00:03 +0400
committerLiam Girdwood <lrg@slimlogic.co.uk>2009-06-15 14:18:27 +0400
commitc8f1e5025ca2fa8e6e037451f3d271e66745a19b (patch)
tree22d0cc384cee47f639163daa15a1d6dff91da1b4
parentb110a8fb242bc34e4b7686252899ce0fca956e2c (diff)
downloadlinux-c8f1e5025ca2fa8e6e037451f3d271e66745a19b.tar.xz
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>
-rw-r--r--drivers/regulator/max1586.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/regulator/max1586.c b/drivers/regulator/max1586.c
index 92799f40c864..2c082d3ef484 100644
--- a/drivers/regulator/max1586.c
+++ b/drivers/regulator/max1586.c
@@ -40,8 +40,8 @@ struct max1586_data {
struct i2c_client *client;
/* min/max V3 voltage */
- int min_uV;
- int max_uV;
+ unsigned int min_uV;
+ unsigned int max_uV;
struct regulator_dev *rdev[0];
};
@@ -199,8 +199,8 @@ static int max1586_pmic_probe(struct i2c_client *client,
ret = -EINVAL;
goto out_unmap;
}
- max1586->min_uV = MAX1586_V3_MIN_UV * pdata->v3_gain / 1000000;
- max1586->max_uV = MAX1586_V3_MAX_UV * pdata->v3_gain / 1000000;
+ max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
+ max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
rdev = max1586->rdev;
for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {