regulator: s2mps11: Copy supported regulators from initconst

Add __initconst to 'regulator_desc' array with supported regulators.
During probe choose how many and which regulators will be supported
according to device ID. Then copy the 'regulator_desc' array to
allocated memory so the regulator core can use it.

Additionally allocate array of of_regulator_match() dynamically (based
on number of regulators) instead of allocation on the stack.

This is needed for supporting different devices in s2mps11
driver and actually prepares the regulator driver for supporting the
S2MPS14 device.

Code for supporting the S2MPS14 device will add its own array of
'regulator_desc' (also marked as __initconst). This way memory footprint
of the driver will be reduced (approximately 'regulators_desc' array for
S2MPS11 occupies 5 kB on 32-bit ARM, for S2MPS14 will occupy 3 kB).

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Chanwoo Choi <[e-mail]>
Cc: Yadwinder Singh Brar <[e-mail]>
Reviewed-by: Yadwinder Singh Brar <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/s2mps11.c

···
 #include <linux/mfd/samsung/core.h>
 #include <linux/mfd/samsung/s2mps11.h>
 
-#define S2MPS11_REGULATOR_CNT ARRAY_SIZE(regulators)
-
 struct s2mps11_info {
+	unsigned int rdev_num;
 	int ramp_delay2;
 	int ramp_delay34;
 	int ramp_delay5;
···
 	.enable_mask	= S2MPS11_ENABLE_MASK			\
 }
 
-static const struct regulator_desc regulators[] = {
+static const struct regulator_desc s2mps11_regulators[] __initconst = {
 	regulator_desc_ldo2(1),
 	regulator_desc_ldo1(2),
 	regulator_desc_ldo1(3),
···
 	regulator_desc_buck10,
 };
 
+/*
+ * Allocates memory under 'regulators' pointer and copies there array
+ * of regulator_desc for given device.
+ *
+ * Returns number of regulators or negative ERRNO on error.
+ */
+static int __init
+s2mps11_pmic_init_regulators_desc(struct platform_device *pdev,
+		struct regulator_desc **regulators)
+{
+	const struct regulator_desc *regulators_init;
+	enum sec_device_type dev_type;
+	int rdev_num;
+
+	dev_type = platform_get_device_id(pdev)->driver_data;
+	switch (dev_type) {
+	case S2MPS11X:
+		rdev_num = ARRAY_SIZE(s2mps11_regulators);
+		regulators_init = s2mps11_regulators;
+		break;
+	default:
+		dev_err(&pdev->dev, "Invalid device type: %u\n", dev_type);
+		return -EINVAL;
+	};
+
+	*regulators = devm_kzalloc(&pdev->dev,
+			sizeof(**regulators) * rdev_num, GFP_KERNEL);
+	if (!*regulators)
+		return -ENOMEM;
+
+	memcpy(*regulators, regulators_init, sizeof(**regulators) * rdev_num);
+
+	return rdev_num;
+}
+
 static int s2mps11_pmic_probe(struct platform_device *pdev)
 {
 	struct sec_pmic_dev *iodev = dev_get_drvdata(pdev->dev.parent);
-	struct sec_platform_data *pdata = dev_get_platdata(iodev->dev);
-	struct of_regulator_match rdata[S2MPS11_REGULATOR_MAX];
+	struct sec_platform_data *pdata = iodev->pdata;
+	struct of_regulator_match *rdata = NULL;
 	struct device_node *reg_np = NULL;
 	struct regulator_config config = { };
 	struct s2mps11_info *s2mps11;
-	int i, ret;
+	int i, ret = 0;
+	struct regulator_desc *regulators = NULL;
+	int rdev_num;
 
 	s2mps11 = devm_kzalloc(&pdev->dev, sizeof(struct s2mps11_info),
 				GFP_KERNEL);
 	if (!s2mps11)
 		return -ENOMEM;
+
+	rdev_num = s2mps11_pmic_init_regulators_desc(pdev, &regulators);
+	if (rdev_num < 0)
+		return rdev_num;
 
 	if (!iodev->dev->of_node) {
 		if (pdata) {
···
 		}
 	}
 
-	for (i = 0; i < S2MPS11_REGULATOR_CNT; i++)
+	rdata = kzalloc(sizeof(*rdata) * rdev_num, GFP_KERNEL);
+	if (!rdata)
+		return -ENOMEM;
+
+	for (i = 0; i < rdev_num; i++)
 		rdata[i].name = regulators[i].name;
 
 	reg_np = of_find_node_by_name(iodev->dev->of_node, "regulators");
 	if (!reg_np) {
 		dev_err(&pdev->dev, "could not find regulators sub-node\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out;
 	}
 
-	of_regulator_match(&pdev->dev, reg_np, rdata, S2MPS11_REGULATOR_MAX);
+	of_regulator_match(&pdev->dev, reg_np, rdata, rdev_num);
 
 common_reg:
 	platform_set_drvdata(pdev, s2mps11);
+	s2mps11->rdev_num = rdev_num;
 
 	config.dev = &pdev->dev;
 	config.regmap = iodev->regmap_pmic;
 	config.driver_data = s2mps11;
-	for (i = 0; i < S2MPS11_REGULATOR_MAX; i++) {
+	for (i = 0; i < rdev_num; i++) {
 		struct regulator_dev *regulator;
 
 		if (!reg_np) {
···
 			ret = PTR_ERR(regulator);
 			dev_err(&pdev->dev, "regulator init failed for %d\n",
 				i);
-			return ret;
+			goto out;
 		}
 	}
 
-	return 0;
+out:
+	kfree(rdata);
+
+	return ret;
 }
 
 static const struct platform_device_id s2mps11_pmic_id[] = {
-	{ "s2mps11-pmic", 0},
+	{ "s2mps11-pmic", S2MPS11X},
 	{ },
 };
 MODULE_DEVICE_TABLE(platform, s2mps11_pmic_id);