mac80211: ath10k: search DT for BDF variant info

Board Data File (BDF) is loaded upon driver boot-up procedure. The right
board data file is identified on QCA4019 using bus, bmi-chip-id and
bmi-board-id.

The problem, however, can occur when the (default) board data file cannot
fulfill the vendor requirements and it is necessary to use a different
board data file.

This problem was solved for SMBIOS by adding a special SMBIOS type 0xF8.
Something similar has to be provided for systems without SMBIOS but with
device trees. No solution was specified by QCA and therefore a new one has
to be found for ath10k.

The device tree requires addition strings to define the variant name

    wifi@a000000 {
    	status = "okay";
    	qcom,ath10k-calibration-variant = "RT-AC58U";
    };

    wifi@a800000 {
    	status = "okay";
    	qcom,ath10k-calibration-variant = "RT-AC58U";
    };

This would create the boarddata identifiers for the board-2.bin search

 *  bus=ahb,bmi-chip-id=0,bmi-board-id=16,variant=RT-AC58U
 *  bus=ahb,bmi-chip-id=0,bmi-board-id=17,variant=RT-AC58U

Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>

package/kernel/mac80211/patches/937-ath10k-calibration-variant.patch

@@ -0,0 +1,106 @@
+From: Sven Eckelmann <sven.eckelmann@openmesh.com>
+Date: Fri, 10 Mar 2017 09:06:15 +0100
+Subject: ath10k: search DT for qcom,ath10k-calibration-variant
+
+Board Data File (BDF) is loaded upon driver boot-up procedure. The right
+board data file is identified on QCA4019 using bus, bmi-chip-id and
+bmi-board-id.
+
+The problem, however, can occur when the (default) board data file cannot
+fulfill the vendor requirements and it is necessary to use a different
+board data file.
+
+This problem was solved for SMBIOS by adding a special SMBIOS type 0xF8.
+Something similar has to be provided for systems without SMBIOS but with
+device trees. No solution was specified by QCA and therefore a new one has
+to be found for ath10k.
+
+The device tree requires addition strings to define the variant name
+
+    wifi@a000000 {
+    	status = "okay";
+    	qcom,ath10k-calibration-variant = "RT-AC58U";
+    };
+
+    wifi@a800000 {
+    	status = "okay";
+    	qcom,ath10k-calibration-variant = "RT-AC58U";
+    };
+
+This would create the boarddata identifiers for the board-2.bin search
+
+ *  bus=ahb,bmi-chip-id=0,bmi-board-id=16,variant=RT-AC58U
+ *  bus=ahb,bmi-chip-id=0,bmi-board-id=17,variant=RT-AC58U
+
+Signed-off-by: Sven Eckelmann <sven.eckelmann@openmesh.com>
+
+Origin: other, https://patchwork.kernel.org/patch/9615185/
+---
+
+--- a/drivers/net/wireless/ath/ath10k/core.c
++++ b/drivers/net/wireless/ath/ath10k/core.c
+@@ -860,6 +860,25 @@ static int ath10k_core_check_smbios(stru
+ 	return 0;
+ }
+ 
++static int ath10k_core_check_dt(struct ath10k *ar)
++{
++	struct device_node *node;
++	const char *variant = NULL;
++
++	node = ar->dev->of_node;
++	if (!node)
++		return -ENOENT;
++
++	of_property_read_string(node, "qcom,ath10k-calibration-variant",
++				&variant);
++	if (!variant)
++		return -ENODATA;
++
++	strscpy(ar->id.bdf_ext, variant, sizeof(ar->id.bdf_ext));
++
++	return 0;
++}
++
+ static int ath10k_download_and_run_otp(struct ath10k *ar)
+ {
+ 	u32 result, address = ar->hw_params.patch_load_addr;
+@@ -1231,19 +1250,19 @@ static int ath10k_core_create_board_name
+ 	/* strlen(',variant=') + strlen(ar->id.bdf_ext) */
+ 	char variant[9 + ATH10K_SMBIOS_BDF_EXT_STR_LENGTH] = { 0 };
+ 
++	if (ar->id.bdf_ext[0] != '\0')
++		scnprintf(variant, sizeof(variant), ",variant=%s",
++			  ar->id.bdf_ext);
++
+ 	if (ar->id.bmi_ids_valid) {
+ 		scnprintf(name, name_len,
+-			  "bus=%s,bmi-chip-id=%d,bmi-board-id=%d",
++			  "bus=%s,bmi-chip-id=%d,bmi-board-id=%d%s",
+ 			  ath10k_bus_str(ar->hif.bus),
+ 			  ar->id.bmi_chip_id,
+-			  ar->id.bmi_board_id);
++			  ar->id.bmi_board_id, variant);
+ 		goto out;
+ 	}
+ 
+-	if (ar->id.bdf_ext[0] != '\0')
+-		scnprintf(variant, sizeof(variant), ",variant=%s",
+-			  ar->id.bdf_ext);
+-
+ 	scnprintf(name, name_len,
+ 		  "bus=%s,vendor=%04x,device=%04x,subsystem-vendor=%04x,subsystem-device=%04x%s",
+ 		  ath10k_bus_str(ar->hif.bus),
+@@ -2343,7 +2362,11 @@ static int ath10k_core_probe_fw(struct a
+ 
+ 	ret = ath10k_core_check_smbios(ar);
+ 	if (ret)
+-		ath10k_dbg(ar, ATH10K_DBG_BOOT, "bdf variant name not set.\n");
++		ath10k_dbg(ar, ATH10K_DBG_BOOT, "SMBIOS bdf variant name not set.\n");
++
++	ret = ath10k_core_check_dt(ar);
++	if (ret)
++		ath10k_dbg(ar, ATH10K_DBG_BOOT, "DT bdf variant name not set.\n");
+ 
+ 	ret = ath10k_core_fetch_board_file(ar);
+ 	if (ret) {