Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit c8f1e502 authored by Philipp Zabel's avatar Philipp Zabel Committed by Liam Girdwood
Browse files

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: default avatarPhilipp Zabel <philipp.zabel@gmail.com>
>
> Looks good.
>
> Acked-by: default avatarMark 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>
parent b110a8fb

drivers/regulator/max1586.c

+4 −4
Original line number Original line Diff line number Diff line
@@ -40,8 +40,8 @@ struct max1586_data { 
	struct i2c_client *client;

	struct i2c_client *client;





	/* min/max V3 voltage */

	/* min/max V3 voltage */

	int min_uV;

	unsigned int min_uV;

	int max_uV;

	unsigned int max_uV;





	struct regulator_dev *rdev[0];

	struct regulator_dev *rdev[0];

};

};
@@ -199,8 +199,8 @@ static int max1586_pmic_probe(struct i2c_client *client, 
		ret = -EINVAL;

		ret = -EINVAL;

		goto out_unmap;

		goto out_unmap;

	}

	}

	max1586->min_uV = MAX1586_V3_MIN_UV * pdata->v3_gain / 1000000;

	max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;

	max1586->max_uV = MAX1586_V3_MAX_UV * pdata->v3_gain / 1000000;

	max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;





	rdev = max1586->rdev;

	rdev = max1586->rdev;

	for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {

	for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {