[PATCH v4 11/11] iio: dac: adi-axi-dac: add registering of child fdt node

[Angelo Dureghello]

From: Angelo Dureghello <adureghello@xxxxxxxxxxxx>

Change to obtain the fdt use case as reported in the
adi,ad3552r.yaml file in this patchset.

The DAC device is defined as a child node of the backend.
Registering the child fdt node as a platform devices.

Signed-off-by: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
---
 drivers/iio/dac/adi-axi-dac.c | 62 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c
index a4147231cd57..c0d965560546 100644
--- a/drivers/iio/dac/adi-axi-dac.c
+++ b/drivers/iio/dac/adi-axi-dac.c
@@ -18,6 +18,7 @@
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
 #include <linux/mutex.h>
+#include <linux/platform_data/ad3552r-hs.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
 #include <linux/regmap.h>
@@ -107,6 +108,8 @@ struct axi_dac_info {
 struct axi_dac_state {
 	struct regmap *regmap;
 	struct device *dev;
+	/* Target DAC platform device */
+	struct platform_device *dac_pdev;
 	/*
 	 * lock to protect multiple accesses to the device registers and global
 	 * data/variables.
@@ -750,6 +753,45 @@ static int axi_dac_bus_reg_read(struct iio_backend *back, u32 reg, u32 *val,
 	return regmap_read(st->regmap, AXI_DAC_CUSTOM_RD_REG, val);
 }
 
+static void axi_dac_child_remove(void *data)
+{
+	struct axi_dac_state *st = data;
+
+	if (st->dac_pdev)
+		platform_device_unregister(st->dac_pdev);
+}
+
+static int axi_dac_create_platform_device(struct axi_dac_state *st,
+					  struct fwnode_handle *child)
+{
+	struct ad3552r_hs_platform_data pdata = {
+		.bus_reg_read = axi_dac_bus_reg_read,
+		.bus_reg_write = axi_dac_bus_reg_write,
+	};
+	struct platform_device_info pi = {
+		.parent = st->dev,
+		.name = fwnode_get_name(child),
+		.id = PLATFORM_DEVID_AUTO,
+		.fwnode = child,
+		.data = &pdata,
+		.size_data = sizeof(pdata),
+	};
+	struct platform_device *pdev;
+	int ret;
+
+	pdev = platform_device_register_full(&pi);
+	if (IS_ERR(pdev))
+		return PTR_ERR(pdev);
+
+	ret = devm_add_action_or_reset(st->dev, axi_dac_child_remove, st);
+	if (ret)
+		return ret;
+
+	st->dac_pdev = pdev;
+
+	return 0;
+}
+
 static const struct iio_backend_ops axi_dac_generic_ops = {
 	.enable = axi_dac_enable,
 	.disable = axi_dac_disable,
@@ -874,6 +916,26 @@ static int axi_dac_probe(struct platform_device *pdev)
 		return dev_err_probe(&pdev->dev, ret,
 				     "failed to register iio backend\n");
 
+	if (st->info->bus_controller) {
+		device_for_each_child_node_scoped(&pdev->dev, child) {
+			int val;
+
+			/* Processing only reg 0 node */
+			ret = fwnode_property_read_u32(child, "reg", &val);
+			if (ret || val != 0)
+				continue;
+
+			ret = fwnode_property_read_u32(child, "io-backends",
+						       &val);
+			if (ret)
+				continue;
+
+			ret = axi_dac_create_platform_device(st, child);
+			if (ret)
+				continue;
+		}
+	}
+
 	dev_info(&pdev->dev, "AXI DAC IP core (%d.%.2d.%c) probed\n",
 		 ADI_AXI_PCORE_VER_MAJOR(ver),
 		 ADI_AXI_PCORE_VER_MINOR(ver),

-- 
2.45.0.rc1