iio: dac: adi-axi-dac: add registering of child fdt node

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.

Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20241028-wip-bl-ad3552r-axi-v0-iio-testing-v9-8-f6960b4f9719@kernel-space.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c
index c2cd8abc33427b09044c4cd5cea299a2965ca156..dd1919441b6dfd3eb9c74caa1a66302a1d878a82 100644 (file)
--- a/drivers/iio/dac/adi-axi-dac.c
+++ b/drivers/iio/dac/adi-axi-dac.c
@@ -29,6 +29,8 @@
 #include <linux/iio/buffer.h>
 #include <linux/iio/iio.h>
 
+#include "ad3552r-hs.h"
+
 /*
  * Register definitions:
  *   https://wiki.analog.com/resources/fpga/docs/axi_dac_ip#register_map
@@ -97,6 +99,7 @@ struct axi_dac_info {
        unsigned int version;
        const struct iio_backend_info *backend_info;
        bool has_dac_clk;
+       bool has_child_nodes;
 };
 
 struct axi_dac_state {
@@ -711,6 +714,36 @@ 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)
+{
+       platform_device_unregister(data);
+}
+
+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,
+               .bus_sample_data_clock_hz = st->dac_clk_rate,
+       };
+       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;
+
+       pdev = platform_device_register_full(&pi);
+       if (IS_ERR(pdev))
+               return PTR_ERR(pdev);
+
+       return devm_add_action_or_reset(st->dev, axi_dac_child_remove, pdev);
+}
+
 static const struct iio_backend_ops axi_dac_generic_ops = {
        .enable = axi_dac_enable,
        .disable = axi_dac_disable,
@@ -852,6 +885,28 @@ static int axi_dac_probe(struct platform_device *pdev)
                return dev_err_probe(&pdev->dev, ret,
                                     "failed to register iio backend\n");
 
+       device_for_each_child_node_scoped(&pdev->dev, child) {
+               int val;
+
+               if (!st->info->has_child_nodes)
+                       return dev_err_probe(&pdev->dev, -EINVAL,
+                                            "invalid fdt axi-dac compatible.");
+
+               /* Processing only reg 0 node */
+               ret = fwnode_property_read_u32(child, "reg", &val);
+               if (ret)
+                       return dev_err_probe(&pdev->dev, ret,
+                                               "invalid reg property.");
+               if (val != 0)
+                       return dev_err_probe(&pdev->dev, -EINVAL,
+                                               "invalid node address.");
+
+               ret = axi_dac_create_platform_device(st, child);
+               if (ret)
+                       return dev_err_probe(&pdev->dev, -EINVAL,
+                                               "cannot create device.");
+       }
+
        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),
@@ -869,6 +924,7 @@ static const struct axi_dac_info dac_ad3552r = {
        .version = ADI_AXI_PCORE_VER(9, 1, 'b'),
        .backend_info = &axi_ad3552r,
        .has_dac_clk = true,
+       .has_child_nodes = true,
 };
 
 static const struct of_device_id axi_dac_of_match[] = {