[PATCH v3 4/4] wcn36xx: Add debugfs entry to read firmware feature strings

["Bryan O'Donoghue" <bryan.odonoghue@xxxxxxxxxx>]

Add in the ability to easily find the firmware feature bits reported in the
get feature exchange without having to compile-in debug prints.

root@linaro-alip:~# cat /sys/kernel/debug/ieee80211/phy0/wcn36xx/firmware_feat_caps
MCC
P2P
DOT11AC
SLM_SESSIONIZATION
DOT11AC_OPMODE
SAP32STA
TDLS
P2P_GO_NOA_DECOUPLE_INIT_SCAN
WLANACTIVE_OFFLOAD
BEACON_OFFLOAD
SCAN_OFFLOAD
BCN_MISS_OFFLOAD
STA_POWERSAVE
STA_ADVANCED_PWRSAVE
BCN_FILTER
RTT
RATECTRL
WOW
WLAN_ROAM_SCAN_OFFLOAD
SPECULATIVE_PS_POLL
IBSS_HEARTBEAT_OFFLOAD
WLAN_SCAN_OFFLOAD
WLAN_PERIODIC_TX_PTRN
ADVANCE_TDLS
BATCH_SCAN
FW_IN_TX_PATH
EXTENDED_NSOFFLOAD_SLOT
CH_SWITCH_V1
HT40_OBSS_SCAN
UPDATE_CHANNEL_LIST
WLAN_MCADDR_FLT
WLAN_CH144
TDLS_SCAN_COEXISTENCE
LINK_LAYER_STATS_MEAS
MU_MIMO
EXTENDED_SCAN
DYNAMIC_WMM_PS
MAC_SPOOFED_SCAN
FW_STATS
WPS_PRBRSP_TMPL
BCN_IE_FLT_DELTA

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
---
 drivers/net/wireless/ath/wcn36xx/debug.c | 39 ++++++++++++++++++++++++
 drivers/net/wireless/ath/wcn36xx/debug.h |  1 +
 2 files changed, 40 insertions(+)

diff --git a/drivers/net/wireless/ath/wcn36xx/debug.c b/drivers/net/wireless/ath/wcn36xx/debug.c
index 6af306ae41ad9..58b3c0501bfde 100644
--- a/drivers/net/wireless/ath/wcn36xx/debug.c
+++ b/drivers/net/wireless/ath/wcn36xx/debug.c
@@ -21,6 +21,7 @@
 #include "wcn36xx.h"
 #include "debug.h"
 #include "pmc.h"
+#include "firmware.h"
 
 #ifdef CONFIG_WCN36XX_DEBUGFS
 
@@ -136,6 +137,42 @@ static const struct file_operations fops_wcn36xx_dump = {
 	.write =       write_file_dump,
 };
 
+static ssize_t read_file_firmware_feature_caps(struct file *file,
+					       char __user *user_buf,
+					       size_t count, loff_t *ppos)
+{
+	struct wcn36xx *wcn = file->private_data;
+	size_t len = 0, buf_len = 2048;
+	char *buf;
+	int i;
+	int ret;
+
+	buf = kzalloc(buf_len, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	mutex_lock(&wcn->hal_mutex);
+	for (i = 0; i < MAX_FEATURE_SUPPORTED; i++) {
+		if (wcn36xx_firmware_get_feat_caps(wcn->fw_feat_caps, i)) {
+			len += scnprintf(buf + len, buf_len - len, "%s\n",
+					 wcn36xx_firmware_get_cap_name(i));
+		}
+		if (len >= buf_len)
+			break;
+	}
+	mutex_unlock(&wcn->hal_mutex);
+
+	ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
+	kfree(buf);
+
+	return ret;
+}
+
+static const struct file_operations fops_wcn36xx_firmware_feat_caps = {
+	.open = simple_open,
+	.read = read_file_firmware_feature_caps,
+};
+
 #define ADD_FILE(name, mode, fop, priv_data)		\
 	do {							\
 		struct dentry *d;				\
@@ -163,6 +200,8 @@ void wcn36xx_debugfs_init(struct wcn36xx *wcn)
 
 	ADD_FILE(bmps_switcher, 0600, &fops_wcn36xx_bmps, wcn);
 	ADD_FILE(dump, 0200, &fops_wcn36xx_dump, wcn);
+	ADD_FILE(firmware_feat_caps, 0200,
+		 &fops_wcn36xx_firmware_feat_caps, wcn);
 }
 
 void wcn36xx_debugfs_exit(struct wcn36xx *wcn)
diff --git a/drivers/net/wireless/ath/wcn36xx/debug.h b/drivers/net/wireless/ath/wcn36xx/debug.h
index 46307aa562d37..7116d96e0543d 100644
--- a/drivers/net/wireless/ath/wcn36xx/debug.h
+++ b/drivers/net/wireless/ath/wcn36xx/debug.h
@@ -31,6 +31,7 @@ struct wcn36xx_dfs_entry {
 	struct dentry *rootdir;
 	struct wcn36xx_dfs_file file_bmps_switcher;
 	struct wcn36xx_dfs_file file_dump;
+	struct wcn36xx_dfs_file file_firmware_feat_caps;
 };
 
 void wcn36xx_debugfs_init(struct wcn36xx *wcn);
-- 
2.36.1