[PATCH 5/9] iio: adc: adi-axi-adc: Add platform children support

Guillaume Stols
2024-11-21T10:18:31Z

This is a preparation for the next commit adding support for register
read and write functions on AD7606.
Since sometimes a bus will be used, it has been agreed during ad3552's
driver implementation that the device's driver bus is the backend, whose
device node will be a child node.
To provide the special callbacks for setting the register, axi-adc needs
to pass them to the child device's driver through platform data.

Signed-off-by: Guillaume Stols <gstols@baylibre.com>
---
drivers/iio/adc/adi-axi-adc.c | 79 ++++++++++++++++++++++++++++++++++++++++---
1 file changed, 74 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
index 5c8c87eb36d1..704ebd6ea83e 100644
--- a/drivers/iio/adc/adi-axi-adc.c
+++ b/drivers/iio/adc/adi-axi-adc.c
@@ -80,7 +80,18 @@
ADI_AXI_REG_CHAN_CTRL_FMT_EN | \
ADI_AXI_REG_CHAN_CTRL_ENABLE)

+struct axi_adc_info {
+ unsigned int version;
+ const struct iio_backend_info *backend_info;
+ bool bus_controller;
+ const void *pdata;
+ unsigned int pdata_sz;
+};
+
struct adi_axi_adc_state {
+ /* Target ADC platform device */
+ struct platform_device *adc_pdev;
+ const struct axi_adc_info *info;
struct regmap *regmap;
struct device *dev;
/* lock to protect multiple accesses to the device registers */
@@ -325,6 +336,40 @@ static const struct regmap_config axi_adc_regmap_config = {
.reg_stride = 4,
};

+static void axi_adc_child_remove(void *data)
+{
+ struct adi_axi_adc_state *st = data;
+
+ platform_device_unregister(st->adc_pdev);
+}
+
+static int axi_adc_create_platform_device(struct adi_axi_adc_state *st,
+ struct fwnode_handle *child)
+{
+ struct platform_device_info pi = {
+ .parent = st->dev,
+ .name = fwnode_get_name(child),
+ .id = PLATFORM_DEVID_AUTO,
+ .fwnode = child,
+ .data = st->info->pdata,
+ .size_data = st->info->pdata_sz,
+ };
+ struct platform_device *pdev;
+ int ret;
+
+ pdev = platform_device_register_full(&pi);
+ if (IS_ERR(pdev))
+ return PTR_ERR(pdev);
+
+ st->adc_pdev = pdev;
+
+ ret = devm_add_action_or_reset(st->dev, axi_adc_child_remove, st);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
static const struct iio_backend_ops adi_axi_adc_ops = {
.enable = axi_adc_enable,
.disable = axi_adc_disable,
@@ -370,7 +415,9 @@ static int adi_axi_adc_probe(struct platform_device *pdev)
return dev_err_probe(&pdev->dev, PTR_ERR(st->regmap),
"failed to init register map\n");

- expected_ver = device_get_match_data(&pdev->dev);
+ st->info = device_get_match_data(&pdev->dev);
+
+ expected_ver = &st->info->version;
if (!expected_ver)
return -ENODEV;

@@ -408,6 +455,25 @@ static int adi_axi_adc_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_adc_create_platform_device(st, child);
+ if (ret)
+ continue;
+ }
+ }
+
dev_info(&pdev->dev, "AXI ADC IP core (%d.%.2d.%c) probed\n",
ADI_AXI_PCORE_VER_MAJOR(ver),
ADI_AXI_PCORE_VER_MINOR(ver),
@@ -416,12 +482,15 @@ static int adi_axi_adc_probe(struct platform_device *pdev)
return 0;
}

-static unsigned int adi_axi_adc_10_0_a_info = ADI_AXI_PCORE_VER(10, 0, 'a');
+static const struct axi_adc_info adc_generic = {
+ .version = ADI_AXI_PCORE_VER(10, 0, 'a'),
+ .backend_info = &adi_axi_adc_generic,
+};
+

-/* Match table for of_platform binding */
static const struct of_device_id adi_axi_adc_of_match[] = {
- { .compatible = "adi,axi-adc-10.0.a", .data = &adi_axi_adc_10_0_a_info },
- { /* end of list */ }
+ { .compatible = "adi,axi-adc-10.0.a", .data = &adc_generic },
+ { }
};
MODULE_DEVICE_TABLE(of, adi_axi_adc_of_match);

--
2.34.1