For M.2 WLAN chips, there is no suitable DTS node to specify the
firmware-name property. In addition, assigning firmware for the
M.2 PCIe interface causes chips that do not use usecase specific
firmware to fail. Therefore, abandoning the approach of specifying
firmware in DTS. As an alternative, propose a static lookup table
mapping device compatible to firmware names. Currently, only WCN6855
HW2.1 requires this.

However, support for the firmware-name property is retained to keep
the ABI backwards compatible.

For details on usecase specific firmware, see:
https://lore.kernel.org/all/20250522013444.1301330-3-miaoqing.pan@oss.qualcomm.com/.

Tested-on: WCN6855 hw2.1 PCI WLAN.HSP.1.1-04685-QCAHSPSWPL_V1_V2_SILICONZ_IOE-1

Fixes: edbbc647c4f3 ("wifi: ath11k: support usercase-specific firmware overrides")
Signed-off-by: Miaoqing Pan <miaoqing.pan@oss.qualcomm.com>
---
 drivers/net/wireless/ath/ath11k/core.c | 36 ++++++++++++++++++++++++++
 drivers/net/wireless/ath/ath11k/core.h |  4 +++
 2 files changed, 40 insertions(+)

diff --git a/drivers/net/wireless/ath/ath11k/core.c b/drivers/net/wireless/ath/ath11k/core.c
index de84906d1b27..1cf7f4e601c3 100644
--- a/drivers/net/wireless/ath/ath11k/core.c
+++ b/drivers/net/wireless/ath/ath11k/core.c
@@ -1044,6 +1044,42 @@ static const struct dmi_system_id ath11k_pm_quirk_table[] = {
 	{}
 };
 
+static const struct __ath11k_core_usecase_firmware_table {
+	u32 hw_rev;
+	const char *compatible;
+	const char *firmware_name;
+} ath11k_core_usecase_firmware_table[] = {
+	{ ATH11K_HW_WCN6855_HW21, "qcom,lemans-evk", "nfa765"},
+	{ ATH11K_HW_WCN6855_HW21, "qcom,monaco-evk", "nfa765"},
+	{ ATH11K_HW_WCN6855_HW21, "qcom,hamoa-iot-evk", "nfa765"},
+	{ /* Sentinel */ }
+};
+
+const char *ath11k_core_get_usecase_firmware(struct ath11k_base *ab)
+{
+	struct device_node *root __free(device_node) = of_find_node_by_path("/");
+	const struct __ath11k_core_usecase_firmware_table *entry = NULL;
+	int i, count = of_property_count_strings(root, "compatible");
+	const char *compatible = NULL;
+
+	for (i = 0; i < count; i++) {
+		if (of_property_read_string_index(root, "compatible", i,
+						  &compatible) < 0)
+			continue;
+
+		entry = ath11k_core_usecase_firmware_table;
+		while (entry->compatible) {
+			if (ab->hw_rev == entry->hw_rev &&
+			    !strcmp(entry->compatible, compatible))
+				return entry->firmware_name;
+			entry++;
+		}
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(ath11k_core_get_usecase_firmware);
+
 void ath11k_fw_stats_pdevs_free(struct list_head *head)
 {
 	struct ath11k_fw_stats_pdev *i, *tmp;
diff --git a/drivers/net/wireless/ath/ath11k/core.h b/drivers/net/wireless/ath/ath11k/core.h
index 3f41e6569a78..a0d725923ef2 100644
--- a/drivers/net/wireless/ath/ath11k/core.h
+++ b/drivers/net/wireless/ath/ath11k/core.h
@@ -1292,6 +1292,7 @@ bool ath11k_core_coldboot_cal_support(struct ath11k_base *ab);
 
 const struct firmware *ath11k_core_firmware_request(struct ath11k_base *ab,
 						    const char *filename);
+const char *ath11k_core_get_usecase_firmware(struct ath11k_base *ab);
 
 static inline const char *ath11k_scan_state_str(enum ath11k_scan_state state)
 {
@@ -1346,6 +1347,9 @@ static inline void ath11k_core_create_firmware_path(struct ath11k_base *ab,
 
 	of_property_read_string(ab->dev->of_node, "firmware-name", &fw_name);
 
+	if (!fw_name)
+		fw_name = ath11k_core_get_usecase_firmware(ab);
+
 	if (fw_name && strncmp(filename, "board", 5))
 		snprintf(buf, buf_len, "%s/%s/%s/%s", ATH11K_FW_DIR,
 			 ab->hw_params.fw.dir, fw_name, filename);
-- 
2.34.1

The firmware-name property was originally introduced to allow end-users
and integrators to select use-case-specific firmware for the WCN6855.
However, specifying firmware for an M.2 WLAN module in the Device Tree
is not appropriate. Instead, this functionality will be handled within
the ath11k driver. Therefore, the firmware-name property is now
deprecated.

Signed-off-by: Miaoqing Pan <miaoqing.pan@oss.qualcomm.com>
---
 .../devicetree/bindings/net/wireless/qcom,ath11k-pci.yaml        | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/net/wireless/qcom,ath11k-pci.yaml b/Documentation/devicetree/bindings/net/wireless/qcom,ath11k-pci.yaml
index e34d42a30192..0162e365798b 100644
--- a/Documentation/devicetree/bindings/net/wireless/qcom,ath11k-pci.yaml
+++ b/Documentation/devicetree/bindings/net/wireless/qcom,ath11k-pci.yaml
@@ -37,6 +37,7 @@ properties:
 
   firmware-name:
     maxItems: 1
+    deprecated: true
     description:
       If present, a board or platform specific string used to lookup
       usecase-specific firmware files for the device.
-- 
2.34.1