[PATCH] mfd: sprd: get subdevices from DT instead for SC27XX SPI

[Chunyan Zhang <zhang.lyra@gmail.com>]

From: Chunyan Zhang <chunyan.zhang@unisoc.com>

SC27XX-SPI added subdevices according to a pre-defined mfd_cell array,
no matter these devices were really included on board. So with this
patch we switch to a new way of detecting subdevices which are
defined in the devicetree.

Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
---
 drivers/mfd/sprd-sc27xx-spi.c | 102 +++++++++++-----------------------
 1 file changed, 31 insertions(+), 71 deletions(-)

diff --git a/drivers/mfd/sprd-sc27xx-spi.c b/drivers/mfd/sprd-sc27xx-spi.c
index 33336cde4724..aa3daa0cfcf5 100644
--- a/drivers/mfd/sprd-sc27xx-spi.c
+++ b/drivers/mfd/sprd-sc27xx-spi.c
@@ -93,73 +93,6 @@ enum usb_charger_type sprd_pmic_detect_charger_type(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(sprd_pmic_detect_charger_type);
 
-static const struct mfd_cell sprd_pmic_devs[] = {
-	{
-		.name = "sc27xx-wdt",
-		.of_compatible = "sprd,sc2731-wdt",
-	}, {
-		.name = "sc27xx-rtc",
-		.of_compatible = "sprd,sc2731-rtc",
-	}, {
-		.name = "sc27xx-charger",
-		.of_compatible = "sprd,sc2731-charger",
-	}, {
-		.name = "sc27xx-chg-timer",
-		.of_compatible = "sprd,sc2731-chg-timer",
-	}, {
-		.name = "sc27xx-fast-chg",
-		.of_compatible = "sprd,sc2731-fast-chg",
-	}, {
-		.name = "sc27xx-chg-wdt",
-		.of_compatible = "sprd,sc2731-chg-wdt",
-	}, {
-		.name = "sc27xx-typec",
-		.of_compatible = "sprd,sc2731-typec",
-	}, {
-		.name = "sc27xx-flash",
-		.of_compatible = "sprd,sc2731-flash",
-	}, {
-		.name = "sc27xx-eic",
-		.of_compatible = "sprd,sc2731-eic",
-	}, {
-		.name = "sc27xx-efuse",
-		.of_compatible = "sprd,sc2731-efuse",
-	}, {
-		.name = "sc27xx-thermal",
-		.of_compatible = "sprd,sc2731-thermal",
-	}, {
-		.name = "sc27xx-adc",
-		.of_compatible = "sprd,sc2731-adc",
-	}, {
-		.name = "sc27xx-audio-codec",
-		.of_compatible = "sprd,sc2731-audio-codec",
-	}, {
-		.name = "sc27xx-regulator",
-		.of_compatible = "sprd,sc2731-regulator",
-	}, {
-		.name = "sc27xx-vibrator",
-		.of_compatible = "sprd,sc2731-vibrator",
-	}, {
-		.name = "sc27xx-keypad-led",
-		.of_compatible = "sprd,sc2731-keypad-led",
-	}, {
-		.name = "sc27xx-bltc",
-		.of_compatible = "sprd,sc2731-bltc",
-	}, {
-		.name = "sc27xx-fgu",
-		.of_compatible = "sprd,sc2731-fgu",
-	}, {
-		.name = "sc27xx-7sreset",
-		.of_compatible = "sprd,sc2731-7sreset",
-	}, {
-		.name = "sc27xx-poweroff",
-		.of_compatible = "sprd,sc2731-poweroff",
-	}, {
-		.name = "sc27xx-syscon",
-		.of_compatible = "sprd,sc2731-syscon",
-	},
-};
-
 static int sprd_pmic_spi_write(void *context, const void *data, size_t count)
 {
 	struct device *dev = context;
@@ -205,6 +138,35 @@ static const struct regmap_config sprd_pmic_config = {
 	.max_register = 0xffff,
 };
 
+static int sprd_pmic_add_subdevices(struct device *dev, int id,
+			 struct irq_domain *domain)
+{
+	int ret = 0;
+	struct device_node *child, *parent = dev->of_node;
+	struct mfd_cell cell = {0};
+	const char *comp;
+	unsigned int prefix_len = strlen("sprd,");
+	char buf[30];
+
+	for_each_child_of_node(parent, child) {
+		comp = of_get_property(child, "compatible", NULL);
+		if (!comp || strncmp("sprd,", comp, prefix_len))
+			return -EINVAL;
+
+		memcpy(buf, comp, strlen(comp) + 1);
+		cell.of_compatible = buf;
+		cell.name = buf + prefix_len;
+
+		ret = devm_mfd_add_devices(dev, id, &cell, 1, NULL, 0, domain);
+		if (ret) {
+			pr_err("devm_mfd_add_devices return fail ret=%d\n", ret);
+			break;
+		}
+	}
+
+	return ret;
+}
+
 static int sprd_pmic_probe(struct spi_device *spi)
 {
 	struct sprd_pmic *ddata;
@@ -263,10 +225,8 @@ static int sprd_pmic_probe(struct spi_device *spi)
 		return ret;
 	}
 
-	ret = devm_mfd_add_devices(&spi->dev, PLATFORM_DEVID_AUTO,
-				   sprd_pmic_devs, ARRAY_SIZE(sprd_pmic_devs),
-				   NULL, 0,
-				   regmap_irq_get_domain(ddata->irq_data));
+	ret = sprd_pmic_add_subdevices(&spi->dev, PLATFORM_DEVID_AUTO,
+				       regmap_irq_get_domain(ddata->irq_data));
 	if (ret) {
 		dev_err(&spi->dev, "Failed to register device %d\n", ret);
 		return ret;
-- 
2.20.1