From c8f1e5025ca2fa8e6e037451f3d271e66745a19b Mon Sep 17 00:00:00 2001 From: Philipp Zabel Date: Thu, 28 May 2009 21:00:03 +0200 Subject: [PATCH] regulator/max1586: fix V3 gain calculation integer overflow On Thu, May 28, 2009 at 10:59 AM, Mark Brown 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 > > Looks good. > > Acked-by: Mark Brown 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 Acked-by: Robert Jarzmik Signed-off-by: Liam Girdwood --- drivers/regulator/max1586.c | 8 ++++---- 1 file 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++) {