[PATCH v4 2/2] regulator: add device tree support for max8997

Thomas Abraham
2012-04-17T18:35:59Z

On 28 March 2012 22:33, Karol Lewandowski <k.lewandowsk@samsung.com> wrote:
> On 24.03.2012 10:49, Thomas Abraham wrote:
>
> Hi Thomas!
>
>> Add device tree based discovery support for max8997.
> ...
>> +Regulators: The regulators of max8997 that have to be instantiated should be
>> +included in a sub-node named 'regulators'. Regulator nodes included in this
>> +sub-node should be of the format as below. Note: The 'n' in LDOn and BUCKn
>> +represents the LDO or BUCK number as per the datasheet of max8997.
>> +
>> + ? ?For LDO's:
>> + ? ? ? ? ? ? LDOn {
>> + ? ? ? ? ? ? ? ? ? ? standard regulator bindings here
>> + ? ? ? ? ? ? };
>> +
>> + ? ?For BUCK's:
>> + ? ? ? ? ? ? BUCKn {
>> + ? ? ? ? ? ? ? ? ? ? standard regulator bindings here
>> + ? ? ? ? ? ? };
>> +
>
>
> Small note - driver supports[1] configuring following regulators by
> using respective DT node names:
>
> ?- EN32KHz_AP
> ?- EN32KHz_CP
> ?- ENVICHG
> ?- ESAFEOUT1
> ?- ESAFEOUT2
> ?- CHARGER
> ?- CHARGER_CV
> ?- CHARGER_TOPOFF
>
> I wonder if these should be mentioned in documentation too.
>
> [1] These are used in e.g. mach-nuri.c

Yes, I missed the above regulators in the documentation. I have
included them now and will resubmit this patch.

>
>> diff --git a/drivers/regulator/max8997.c b/drivers/regulator/max8997.c> index 9657929..dce8aaf 100644
>
>> --- a/drivers/regulator/max8997.c
>> +++ b/drivers/regulator/max8997.c
> ..
>> +static int max8997_pmic_dt_parse_pdata(struct max8997_dev *iodev,
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? struct max8997_platform_data *pdata)
>> +{
>> + ? ? struct device_node *pmic_np, *regulators_np, *reg_np;
>> + ? ? struct max8997_regulator_data *rdata;
>> + ? ? unsigned int i, dvs_voltage_nr = 1, ret;
>> +
>> + ? ? pmic_np = iodev->dev->of_node;
>> + ? ? if (!pmic_np) {
>> + ? ? ? ? ? ? dev_err(iodev->dev, "could not find pmic sub-node\n");
>> + ? ? ? ? ? ? return -ENODEV;
>> + ? ? }
>> +
>> + ? ? regulators_np = of_find_node_by_name(pmic_np, "regulators");
>> + ? ? if (!regulators_np) {
>> + ? ? ? ? ? ? dev_err(iodev->dev, "could not find regulators sub-node\n");
>> + ? ? ? ? ? ? return -EINVAL;
>> + ? ? }
>> +
>> + ? ? /* count the number of regulators to be supported in pmic */
>> + ? ? pdata->num_regulators = 0;
>> + ? ? for_each_child_of_node(regulators_np, reg_np)
>> + ? ? ? ? ? ? pdata->num_regulators++;
>> +
>> + ? ? rdata = devm_kzalloc(iodev->dev, sizeof(*rdata) *
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? pdata->num_regulators, GFP_KERNEL);
>> + ? ? if (!rdata) {
>> + ? ? ? ? ? ? dev_err(iodev->dev, "could not allocate memory for "
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? "regulator data\n");
>> + ? ? ? ? ? ? return -ENOMEM;
>> + ? ? }
>
>> + ? ? pdata->regulators = rdata;
>
>> + ? ? for_each_child_of_node(regulators_np, reg_np) {
>> + ? ? ? ? ? ? for (i = 0; i < ARRAY_SIZE(regulators); i++)
>> + ? ? ? ? ? ? ? ? ? ? if (!of_node_cmp(reg_np->name, regulators[i].name))
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? break;
>> + ? ? ? ? ? ? rdata->id = i;
>
>
> rdata->id will be equal to ARRAY_SIZE(regulators) when one adds DT node
> name (below "regulators") which is different from what can be found in
> regulators[] table.
>
> On my test machine this results in hard lockup - possibly because
> something tries to access regulators[ARRAY_SIZE(regulators)]
> later on.
>
> Following patch fixes this on my machine (using DTS with misspelled LDO1 for LDx1):
>
> diff --git a/drivers/regulator/max8997.c b/drivers/regulator/max8997.c
> index dce8aaf..c20fd72 100644
> --- a/drivers/regulator/max8997.c
> +++ b/drivers/regulator/max8997.c
> @@ -1011,6 +1011,13 @@ static int max8997_pmic_dt_parse_pdata(struct max8997_dev *iodev,
> ? ? ? ? ? ? ? ?for (i = 0; i < ARRAY_SIZE(regulators); i++)
> ? ? ? ? ? ? ? ? ? ? ? ?if (!of_node_cmp(reg_np->name, regulators[i].name))
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?break;
> +
> + ? ? ? ? ? ? ? if (i == ARRAY_SIZE(regulators)) {
> + ? ? ? ? ? ? ? ? ? ? ? dev_warn(iodev->dev, "don't know how to configure regulator %s\n",
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?reg_np->name);
> + ? ? ? ? ? ? ? ? ? ? ? continue;
> + ? ? ? ? ? ? ? }
> +
> ? ? ? ? ? ? ? ?rdata->id = i;
> ? ? ? ? ? ? ? ?rdata->initdata = of_get_regulator_init_data(
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?iodev->dev, reg_np);
>

Thanks for this fix. I have merged this change into this patch.

Regards,
Thomas.

>
> Regards,
> --
> Karol Lewandowski | Samsung Poland R&D Center | Linux/Platform