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

..

+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);

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