[PATCH v4 2/2] ath11k: add read variant from SMBIOS for download board data

[Wen Gong <quic_wgong@xxxxxxxxxxx>]

This is to read variant from SMBIOS such as read from DT, the variant
string will be used to one part of string which used to search board
data from board-2.bin.

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-01720.1-QCAHSPSWPL_V1_V2_SILICONZ_LITE-1

Signed-off-by: Wen Gong <quic_wgong@xxxxxxxxxxx>
---
 drivers/net/wireless/ath/ath11k/core.c | 74 ++++++++++++++++++++++++++
 drivers/net/wireless/ath/ath11k/core.h | 11 ++++
 drivers/net/wireless/ath/ath11k/qmi.c  |  4 ++
 3 files changed, 89 insertions(+)

diff --git a/drivers/net/wireless/ath/ath11k/core.c b/drivers/net/wireless/ath/ath11k/core.c
index 17832b4c37bd..4d0e3b465da0 100644
--- a/drivers/net/wireless/ath/ath11k/core.c
+++ b/drivers/net/wireless/ath/ath11k/core.c
@@ -8,6 +8,9 @@
 #include <linux/remoteproc.h>
 #include <linux/firmware.h>
 #include <linux/of.h>
+#include <linux/dmi.h>
+#include <linux/ctype.h>
+
 #include "core.h"
 #include "dp_tx.h"
 #include "dp_rx.h"
@@ -437,6 +440,77 @@ int ath11k_core_resume(struct ath11k_base *ab)
 }
 EXPORT_SYMBOL(ath11k_core_resume);
 
+static void ath11k_core_check_bdfext(const struct dmi_header *hdr, void *data)
+{
+	struct ath11k_base *ab = data;
+	const char *bdf_ext;
+	const char *magic = ATH11K_SMBIOS_BDF_EXT_MAGIC;
+	u8 bdf_enabled;
+	int i;
+	size_t len;
+
+	if (ab->qmi.target.bdf_ext[0] != '\0')
+		return;
+
+	if (hdr->type != ATH11K_SMBIOS_BDF_EXT_TYPE)
+		return;
+
+	if (hdr->length != ATH11K_SMBIOS_BDF_EXT_LENGTH) {
+		ath11k_dbg(ab, ATH11K_DBG_BOOT,
+			   "wrong smbios bdf ext type length (%d).\n",
+			   hdr->length);
+		return;
+	}
+
+	bdf_enabled = *((u8 *)hdr + ATH11K_SMBIOS_BDF_EXT_OFFSET);
+	if (!bdf_enabled) {
+		ath11k_dbg(ab, ATH11K_DBG_BOOT, "bdf variant name not found.\n");
+		return;
+	}
+
+	/* Only one string exists (per spec) */
+	bdf_ext = (char *)hdr + hdr->length;
+
+	if (memcmp(bdf_ext, magic, strlen(magic)) != 0) {
+		ath11k_dbg(ab, ATH11K_DBG_BOOT,
+			   "bdf variant magic does not match.\n");
+		return;
+	}
+
+	len = strlen(bdf_ext);
+	for (i = 0; i < len; i++) {
+		if (!isascii(bdf_ext[i]) || !isprint(bdf_ext[i])) {
+			ath11k_dbg(ab, ATH11K_DBG_BOOT,
+				   "bdf variant name contains non ascii chars.\n");
+			return;
+		}
+	}
+
+	/* Copy extension name without magic prefix */
+	if (strscpy(ab->qmi.target.bdf_ext, bdf_ext + strlen(magic),
+		    sizeof(ab->qmi.target.bdf_ext)) < 0) {
+		ath11k_dbg(ab, ATH11K_DBG_BOOT,
+			   "bdf variant string is longer than the buffer can accommodate (variant: %s)\n",
+			    bdf_ext);
+		return;
+	}
+
+	ath11k_dbg(ab, ATH11K_DBG_BOOT,
+		   "found and validated bdf variant smbios_type 0x%x bdf %s\n",
+		   ATH11K_SMBIOS_BDF_EXT_TYPE, bdf_ext);
+}
+
+int ath11k_core_check_smbios(struct ath11k_base *ab)
+{
+	ab->qmi.target.bdf_ext[0] = '\0';
+	dmi_walk(ath11k_core_check_bdfext, ab);
+
+	if (ab->qmi.target.bdf_ext[0] == '\0')
+		return -ENODATA;
+
+	return 0;
+}
+
 int ath11k_core_check_dt(struct ath11k_base *ab)
 {
 	size_t max_len = sizeof(ab->qmi.target.bdf_ext);
diff --git a/drivers/net/wireless/ath/ath11k/core.h b/drivers/net/wireless/ath/ath11k/core.h
index 1d13e6124693..ac88874598c2 100644
--- a/drivers/net/wireless/ath/ath11k/core.h
+++ b/drivers/net/wireless/ath/ath11k/core.h
@@ -960,7 +960,18 @@ int ath11k_core_fetch_bdf(struct ath11k_base *ath11k,
 			  struct ath11k_board_data *bd);
 void ath11k_core_free_bdf(struct ath11k_base *ab, struct ath11k_board_data *bd);
 int ath11k_core_check_dt(struct ath11k_base *ath11k);
+/* SMBIOS type containing Board Data File Name Extension */
+#define ATH11K_SMBIOS_BDF_EXT_TYPE 0xF8
 
+/* SMBIOS type structure length (excluding strings-set) */
+#define ATH11K_SMBIOS_BDF_EXT_LENGTH 0x9
+
+/* Offset pointing to Board Data File Name Extension */
+#define ATH11K_SMBIOS_BDF_EXT_OFFSET 0x8
+
+/* The magic used by QCA spec */
+#define ATH11K_SMBIOS_BDF_EXT_MAGIC "BDF_"
+int ath11k_core_check_smbios(struct ath11k_base *ab);
 void ath11k_core_halt(struct ath11k *ar);
 int ath11k_core_resume(struct ath11k_base *ab);
 int ath11k_core_suspend(struct ath11k_base *ab);
diff --git a/drivers/net/wireless/ath/ath11k/qmi.c b/drivers/net/wireless/ath/ath11k/qmi.c
index 25eb22cbeaeb..700a9c137018 100644
--- a/drivers/net/wireless/ath/ath11k/qmi.c
+++ b/drivers/net/wireless/ath/ath11k/qmi.c
@@ -1991,6 +1991,10 @@ static int ath11k_qmi_request_target_cap(struct ath11k_base *ab)
 		    ab->qmi.target.fw_build_timestamp,
 		    ab->qmi.target.fw_build_id);
 
+	r = ath11k_core_check_smbios(ab);
+	if (r)
+		ath11k_dbg(ab, ATH11K_DBG_QMI, "SMBIOS bdf variant name not set.\n");
+
 	r = ath11k_core_check_dt(ab);
 	if (r)
 		ath11k_dbg(ab, ATH11K_DBG_QMI, "DT bdf variant name not set.\n");
-- 
2.31.1