Messages in this thread Patch in this message | | | From | Philipp Zabel <> | Subject | [PATCH] regulator/max1586: fix V3 gain calculation integer overflow | Date | Thu, 28 May 2009 21:00:03 +0200 |
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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> --- drivers/regulator/max1586.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/regulator/max1586.c b/drivers/regulator/max1586.c index 92799f4..2c082d3 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++) { -- 1.6.3.1
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