[PATCH 18/28] dpll: zl3073x: Read optional pin properties from firmware

Ivan Vecera
2025-04-07T17:32:52Z

The firmware (DT, ACPI...) can specify properties for particular
pins. Input pins are stored in 'input-pins' sub-node and output
pins in 'output-pins'. Each pin is represented by separate node
in 'input-pins' or 'output-pins'.

The properties that are supported:
* reg - integer that specifies pin index
* label - string that is used by driver as board label
* type - string that indicates pin type

Reviewed-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
drivers/dpll/dpll_zl3073x.c | 102 ++++++++++++++++++++++++++++++++++--
1 file changed, 98 insertions(+), 4 deletions(-)

diff --git a/drivers/dpll/dpll_zl3073x.c b/drivers/dpll/dpll_zl3073x.c
index 3ff53a333a6e9..cf2cdd6dec263 100644
--- a/drivers/dpll/dpll_zl3073x.c
+++ b/drivers/dpll/dpll_zl3073x.c
@@ -73,10 +73,12 @@ ZL3073X_REG8_IDX_DEF(dpll_ref_prio, 0x652,
* struct zl3073x_dpll_pin_info - DPLL pin info
* @props: DPLL core pin properties
* @package_label: pin package label
+ * @fwnode: pin firmware node
*/
struct zl3073x_dpll_pin_info {
struct dpll_pin_properties props;
char package_label[8];
+ struct fwnode_handle *fwnode;
};

/**
@@ -482,6 +484,62 @@ static const struct dpll_device_ops zl3073x_dpll_device_ops = {
.mode_get = zl3073x_dpll_mode_get,
};

+/**
+ * zl3073x_dpll_pin_fwnode_get - get fwnode for given pin
+ * pin: pointer to pin structure
+ *
+ * The caller is responsible for calling fwnode_handle_put() on the returned
+ * fwnode pointer.
+ *
+ * Returns the firmware node for the given pin if it is present or
+ * NULL if it is missing.
+ */
+static struct fwnode_handle *
+zl3073x_dpll_pin_fwnode_get(struct zl3073x_dpll_pin *pin)
+{
+ struct zl3073x_dpll *zldpll = pin_to_dpll(pin);
+ struct fwnode_handle *pins_node, *pin_node;
+ const char *node_name;
+ u8 idx;
+
+ if (zl3073x_dpll_is_input_pin(pin))
+ node_name = "input-pins";
+ else
+ node_name = "output-pins";
+
+ /* Get node containing input or output pins */
+ pins_node = device_get_named_child_node(zldpll->mfd->dev, node_name);
+ if (!pins_node) {
+ dev_dbg(zldpll->mfd->dev, "'%s' sub-node is missing\n",
+ node_name);
+ return NULL;
+ }
+
+ /* Get pin HW index */
+ idx = zl3073x_dpll_pin_index_get(pin);
+
+ /* Enumerate pin nodes and find the requested one */
+ fwnode_for_each_child_node(pins_node, pin_node) {
+ u32 reg;
+
+ if (fwnode_property_read_u32(pin_node, "reg", &reg))
+ continue;
+
+ if (idx == reg)
+ break;
+ }
+
+ /* Release pin parent node */
+ fwnode_handle_put(pins_node);
+
+ dev_dbg(zldpll->mfd->dev, "Firmware node for %s%u%c %sfound\n",
+ zl3073x_dpll_is_input_pin(pin) ? "REF" : "OUT", idx / 2,
+ zl3073x_dpll_is_p_pin(pin) ? 'P' : 'N',
+ pin_node ? "" : "NOT ");
+
+ return pin_node;
+}
+
/**
* zl3073x_dpll_pin_info_package_label_set - generate package label for the pin
* @pin: pointer to pin
@@ -548,8 +606,10 @@ zl3073x_dpll_pin_info_package_label_set(struct zl3073x_dpll_pin *pin,
* zl3073x_dpll_pin_info_get - get pin info
* @pin: pin whose info is returned
*
- * The function allocates pin info structure, generates package label
- * string according pin type and its order number.
+ * The function looks for firmware node for the given pin if it is provided
+ * by the system firmware (DT or ACPI), allocates pin info structure,
+ * generates package label string according pin type and its order number
+ * and optionally fetches board label from the firmware node if it exists.
*
* Returns pointer to allocated pin info structure that has to be freed
* by @zl3073x_dpll_pin_info_put by the caller and in case of error
@@ -558,14 +618,16 @@ zl3073x_dpll_pin_info_package_label_set(struct zl3073x_dpll_pin *pin,
static struct zl3073x_dpll_pin_info *
zl3073x_dpll_pin_info_get(struct zl3073x_dpll_pin *pin)
{
+ struct zl3073x_dev *zldev = pin_to_dev(pin);
struct zl3073x_dpll_pin_info *pin_info;
+ const char *pin_type;

/* Allocate pin info structure */
pin_info = kzalloc(sizeof(*pin_info), GFP_KERNEL);
if (!pin_info)
return ERR_PTR(-ENOMEM);

- /* Set pin type */
+ /* Set default pin type */
if (zl3073x_dpll_is_input_pin(pin))
pin_info->props.type = DPLL_PIN_TYPE_EXT;
else
@@ -577,6 +639,34 @@ zl3073x_dpll_pin_info_get(struct zl3073x_dpll_pin *pin)
/* Generate package label for the given pin */
zl3073x_dpll_pin_info_package_label_set(pin, pin_info);

+ /* Get firmware node for the given pin */
+ pin_info->fwnode = zl3073x_dpll_pin_fwnode_get(pin);
+ if (!pin_info->fwnode)
+ /* Return if it does not exist */
+ return pin_info;
+
+ /* Look for label property and store the value as board label */
+ fwnode_property_read_string(pin_info->fwnode, "label",
+ &pin_info->props.board_label);
+
+ /* Look for pin type property and translate its value to DPLL
+ * pin type enum if it is present.
+ */
+ if (!fwnode_property_read_string(pin_info->fwnode, "type", &pin_type)) {
+ if (!strcmp(pin_type, "ext"))
+ pin_info->props.type = DPLL_PIN_TYPE_EXT;
+ else if (!strcmp(pin_type, "gnss"))
+ pin_info->props.type = DPLL_PIN_TYPE_GNSS;
+ else if (!strcmp(pin_type, "int"))
+ pin_info->props.type = DPLL_PIN_TYPE_INT_OSCILLATOR;
+ else if (!strcmp(pin_type, "synce"))
+ pin_info->props.type = DPLL_PIN_TYPE_SYNCE_ETH_PORT;
+ else
+ dev_warn(zldev->dev,
+ "Unknown or unsupported pin type '%s'\n",
+ pin_type);
+ }
+
return pin_info;
}

@@ -584,11 +674,15 @@ zl3073x_dpll_pin_info_get(struct zl3073x_dpll_pin *pin)
* zl3073x_dpll_pin_info_put - free pin info
* @pin_info: pin info to free
*
- * The function deallocates given pin info structure.
+ * The function deallocates given pin info structure and firmware node handle.
*/
static void
zl3073x_dpll_pin_info_put(struct zl3073x_dpll_pin_info *pin_info)
{
+ /* Put firmware handle if it is present */
+ if (pin_info->fwnode)
+ fwnode_handle_put(pin_info->fwnode);
+
/* Free the pin info structure itself */
kfree(pin_info);
}
--
2.48.1