[PATCH v2 2/3] fsi: occ: Support probing the hwmon child device from dts node

Eddie James
2022-08-09T20:08:19Z

There is now a need for reading devicetree properties in the OCC
hwmon driver, which isn't current supported as the FSI driver just
instantiates a basic platform device. Add support for this use case
by checking for an "occ-hwmon" node and if present, creating an
OF device from it.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
drivers/fsi/fsi-occ.c | 41 ++++++++++++++++++++++++++++++++++-------
1 file changed, 34 insertions(+), 7 deletions(-)

diff --git a/drivers/fsi/fsi-occ.c b/drivers/fsi/fsi-occ.c
index 8f7f602b909d..abdd37d5507f 100644
--- a/drivers/fsi/fsi-occ.c
+++ b/drivers/fsi/fsi-occ.c
@@ -44,6 +44,7 @@ struct occ {
struct device *sbefifo;
char name[32];
int idx;
+ bool platform_hwmon;
u8 sequence_number;
void *buffer;
void *client_buffer;
@@ -598,7 +599,7 @@ int fsi_occ_submit(struct device *dev, const void *request, size_t req_len,
}
EXPORT_SYMBOL_GPL(fsi_occ_submit);

-static int occ_unregister_child(struct device *dev, void *data)
+static int occ_unregister_platform_child(struct device *dev, void *data)
{
struct platform_device *hwmon_dev = to_platform_device(dev);

@@ -607,12 +608,25 @@ static int occ_unregister_child(struct device *dev, void *data)
return 0;
}

+static int occ_unregister_of_child(struct device *dev, void *data)
+{
+ struct platform_device *hwmon_dev = to_platform_device(dev);
+
+ of_device_unregister(hwmon_dev);
+ if (dev->of_node)
+ of_node_clear_flag(dev->of_node, OF_POPULATED);
+
+ return 0;
+}
+
static int occ_probe(struct platform_device *pdev)
{
int rc;
u32 reg;
+ char child_name[32];
struct occ *occ;
- struct platform_device *hwmon_dev;
+ struct platform_device *hwmon_dev = NULL;
+ struct device_node *hwmon_node;
struct device *dev = &pdev->dev;
struct platform_device_info hwmon_dev_info = {
.parent = dev,
@@ -671,10 +685,20 @@ static int occ_probe(struct platform_device *pdev)
return rc;
}

- hwmon_dev_info.id = occ->idx;
- hwmon_dev = platform_device_register_full(&hwmon_dev_info);
- if (IS_ERR(hwmon_dev))
- dev_warn(dev, "failed to create hwmon device\n");
+ hwmon_node = of_get_child_by_name(dev->of_node, hwmon_dev_info.name);
+ if (hwmon_node) {
+ snprintf(child_name, sizeof(child_name), "%s.%d", hwmon_dev_info.name, occ->idx);
+ hwmon_dev = of_platform_device_create(hwmon_node, child_name, dev);
+ of_node_put(hwmon_node);
+ }
+
+ if (!hwmon_dev) {
+ occ->platform_hwmon = true;
+ hwmon_dev_info.id = occ->idx;
+ hwmon_dev = platform_device_register_full(&hwmon_dev_info);
+ if (IS_ERR(hwmon_dev))
+ dev_warn(dev, "failed to create hwmon device\n");
+ }

return 0;
}
@@ -690,7 +714,10 @@ static int occ_remove(struct platform_device *pdev)
occ->buffer = NULL;
mutex_unlock(&occ->occ_lock);

- device_for_each_child(&pdev->dev, NULL, occ_unregister_child);
+ if (occ->platform_hwmon)
+ device_for_each_child(&pdev->dev, NULL, occ_unregister_platform_child);
+ else
+ device_for_each_child(&pdev->dev, NULL, occ_unregister_of_child);

ida_simple_remove(&occ_ida, occ->idx);

--
2.31.1