mt76: mt7915: add support for tx-overrides

Allow setting fix rate on transmit without using full testmode
logic.

txpower, dynbw, retry count is not currently supported.
And, probably later need additional logic to not apply this
txo to non-data frames and to smaller frames, to allow
ARP and such to go through while also forcing test data frames
to arbitrary tx-rates (rates which very well may not be
received by peer.)

Signed-off-by: Ben Greear <greearb@candelatech.com>

drivers/net/wireless/mediatek/mt76/mt76.h

@@ -577,6 +577,7 @@ struct mt76_testmode_ops {
 
 struct mt76_testmode_data {
 	enum mt76_testmode_state state;
+	u8 txo_active; /* tx overrides are active */
 
 	u32 param_set[DIV_ROUND_UP(NUM_MT76_TM_ATTRS, 32)];
 	struct sk_buff *tx_skb;
@@ -591,6 +592,9 @@ struct mt76_testmode_data {
 	u8 tx_rate_ldpc;
 	u8 tx_rate_stbc;
 	u8 tx_ltf;
+	u8 txbw; /* specify TX bandwidth: 0 20Mhz, 1 40Mhz, 2 80Mhz, 3 160Mhz */
+	u8 tx_xmit_count; /* 0 means no-ack, 1 means one transmit, etc */
+	u8 tx_dynbw; /* 0:  dynamic bw disabled, 1: dynamic bw enabled */
 
 	u8 tx_antenna_mask;
 	u8 tx_spe_idx;

drivers/net/wireless/mediatek/mt76/mt7915/debugfs.c

@@ -190,6 +190,228 @@ mt7915_fw_util_wa_show(struct seq_file *file, void *data)
 
 DEFINE_SHOW_ATTRIBUTE(mt7915_fw_util_wa);
 
+struct mt7915_txo_worker_info {
+	char* buf;
+	int sofar;
+	int size;
+};
+
+static void mt7915_txo_worker(void *wi_data, struct ieee80211_sta *sta)
+{
+	struct mt7915_txo_worker_info *wi = wi_data;
+	struct mt7915_sta *msta = (struct mt7915_sta *)sta->drv_priv;
+	struct mt76_testmode_data *td = &msta->test;
+	struct ieee80211_vif *vif;
+	struct wireless_dev *wdev;
+
+	if (wi->sofar >= wi->size)
+		return; /* buffer is full */
+
+	vif = container_of((void *)msta->vif, struct ieee80211_vif, drv_priv);
+	wdev = ieee80211_vif_to_wdev(vif);
+
+	wi->sofar += scnprintf(wi->buf + wi->sofar, wi->size - wi->sofar,
+			       "vdev (%s) active=%d tpc=%d sgi=%d mcs=%d nss=%d"
+			       " pream=%d retries=%d dynbw=%d bw=%d\n",
+			       wdev->netdev->name,
+			       td->txo_active, td->tx_power[0],
+			       td->tx_rate_sgi, td->tx_rate_idx,
+			       td->tx_rate_nss, td->tx_rate_mode,
+			       td->tx_xmit_count, td->tx_dynbw,
+			       td->txbw);
+}
+
+static ssize_t mt7915_read_set_rate_override(struct file *file,
+					     char __user *user_buf,
+					     size_t count, loff_t *ppos)
+{
+	struct mt7915_dev *dev = file->private_data;
+        struct ieee80211_hw *hw = dev->mphy.hw;
+	char *buf2;
+	int size = 8000;
+	int rv, sofar;
+	struct mt7915_txo_worker_info wi;
+	const char buf[] =
+		"This allows specify specif tx rate parameters for all DATA"
+		" frames on a vdev\n"
+		"To set a value, you specify the dev-name and key-value pairs:\n"
+		"tpc=10 sgi=1 mcs=x nss=x pream=x retries=x dynbw=0|1 bw=x enable=0|1\n"
+		"pream: 0=cck, 1=ofdm, 2=HT, 3=VHT, 4=HE_SU\n"
+		"cck-mcs: 0=1Mbps, 1=2Mbps, 3=5.5Mbps, 3=11Mbps\n"
+		"ofdm-mcs: 0=6Mbps, 1=9Mbps, 2=12Mbps, 3=18Mbps, 4=24Mbps, 5=36Mbps,"
+		" 6=48Mbps, 7=54Mbps\n"
+		"tpc is not implemented currently, bw is 0-3 for 20-160\n"
+		" For example, wlan0:\n"
+		"echo \"wlan0 tpc=255 sgi=1 mcs=0 nss=1 pream=3 retries=1 dynbw=0 bw=0"
+		" active=1\" > ...mt76/set_rate_override\n";
+
+	buf2 = kzalloc(size, GFP_KERNEL);
+	if (!buf2)
+		return -ENOMEM;
+	strcpy(buf2, buf);
+	sofar = strlen(buf2);
+
+	wi.sofar = sofar;
+	wi.buf = buf2;
+	wi.size = size;
+
+	ieee80211_iterate_stations_atomic(hw, mt7915_txo_worker, &wi);
+
+	rv = simple_read_from_buffer(user_buf, count, ppos, buf2, wi.sofar);
+	kfree(buf2);
+	return rv;
+}
+
+/* Set the rates for specific types of traffic.
+ */
+static ssize_t mt7915_write_set_rate_override(struct file *file,
+					      const char __user *user_buf,
+					      size_t count, loff_t *ppos)
+{
+	struct mt7915_dev *dev = file->private_data;
+	struct mt7915_sta *msta;
+	struct ieee80211_vif *vif;
+	struct mt76_testmode_data *td = NULL;
+	struct wireless_dev *wdev;
+	struct mt76_wcid *wcid;
+	struct mt76_phy *mphy = &dev->mt76.phy;
+	char buf[180];
+	char tmp[20];
+	char *tok;
+	int ret, i, j;
+	unsigned int vdev_id = 0xFFFF;
+	char *bufptr = buf;
+	long rc;
+	char dev_name_match[IFNAMSIZ + 2];
+
+	memset(buf, 0, sizeof(buf));
+
+	simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, user_buf, count);
+
+	/* make sure that buf is null terminated */
+	buf[sizeof(buf) - 1] = 0;
+
+	/* drop the possible '\n' from the end */
+	if (buf[count - 1] == '\n')
+		buf[count - 1] = 0;
+
+	mutex_lock(&mphy->dev->mutex);
+
+	/* Ignore empty lines, 'echo' appends them sometimes at least. */
+	if (buf[0] == 0) {
+		ret = count;
+		goto exit;
+	}
+
+	/* String starts with vdev name, ie 'wlan0'  Find the proper vif that
+	 * matches the name.
+	 */
+	for (i = 0; i < ARRAY_SIZE(dev->mt76.wcid_mask); i++) {
+		u32 mask = dev->mt76.wcid_mask[i];
+		u32 phy_mask = dev->mt76.wcid_phy_mask[i];
+
+		if (!mask)
+			continue;
+
+		for (j = i * 32; mask; j++, mask >>= 1, phy_mask >>= 1) {
+			if (!(mask & 1))
+				continue;
+
+			wcid = rcu_dereference(dev->mt76.wcid[j]);
+			if (!wcid)
+				continue;
+
+			msta = container_of(wcid, struct mt7915_sta, wcid);
+
+			vif = container_of((void *)msta->vif, struct ieee80211_vif, drv_priv);
+
+			wdev = ieee80211_vif_to_wdev(vif);
+
+			if (!wdev)
+				continue;
+
+			snprintf(dev_name_match, sizeof(dev_name_match) - 1, "%s ",
+				 wdev->netdev->name);
+
+			if (strncmp(dev_name_match, buf, strlen(dev_name_match)) == 0) {
+				vdev_id = j;
+				td = &msta->test;
+				bufptr = buf + strlen(dev_name_match) - 1;
+				break;
+			}
+		}
+	}
+
+	if (vdev_id == 0xFFFF) {
+		if (strstr(buf, "active=0")) {
+			/* Ignore, we are disabling it anyway */
+			ret = count;
+			goto exit;
+		} else {
+			dev_info(dev->mt76.dev,
+				 "mt7915: set-rate-override, unknown netdev name: %s\n", buf);
+		}
+		ret = -EINVAL;
+		goto exit;
+	}
+
+#define MT7915_PARSE_LTOK(a, b)					\
+	do {								\
+		tok = strstr(bufptr, " " #a "=");			\
+		if (tok) {						\
+			char *tspace;					\
+			tok += 1; /* move past initial space */		\
+			strncpy(tmp, tok + strlen(#a "="), sizeof(tmp) - 1); \
+			tmp[sizeof(tmp) - 1] = 0;			\
+			tspace = strstr(tmp, " ");			\
+			if (tspace)					\
+				*tspace = 0;				\
+			if (kstrtol(tmp, 0, &rc) != 0)			\
+				dev_info(dev->mt76.dev,			\
+					 "mt7915: set-rate-override: " #a \
+					 "= could not be parsed, tmp: %s\n", \
+					 tmp);				\
+			else						\
+				td->b = rc;				\
+		}							\
+	} while (0)
+
+	/* TODO:  Allow configuring LTF? */
+	td->tx_ltf = 1; /* 0: HTLTF 3.2us, 1: HELTF, 6.4us, 2 HELTF 12,8us */
+
+	MT7915_PARSE_LTOK(tpc, tx_power[0]);
+	MT7915_PARSE_LTOK(sgi, tx_rate_sgi);
+	MT7915_PARSE_LTOK(mcs, tx_rate_idx);
+	MT7915_PARSE_LTOK(nss, tx_rate_nss);
+	MT7915_PARSE_LTOK(pream, tx_rate_mode);
+	MT7915_PARSE_LTOK(retries, tx_xmit_count);
+	MT7915_PARSE_LTOK(dynbw, tx_dynbw);
+	MT7915_PARSE_LTOK(bw, txbw);
+	MT7915_PARSE_LTOK(active, txo_active);
+
+	dev_info(dev->mt76.dev,
+		 "mt7915: set-rate-overrides, vdev %i(%s) active=%d tpc=%d sgi=%d mcs=%d"
+		 " nss=%d pream=%d retries=%d dynbw=%d bw=%d\n",
+		 vdev_id, dev_name_match,
+		 td->txo_active, td->tx_power[0], td->tx_rate_sgi, td->tx_rate_idx,
+		 td->tx_rate_nss, td->tx_rate_mode, td->tx_xmit_count, td->tx_dynbw,
+		 td->txbw);
+
+	ret = count;
+
+exit:
+	mutex_unlock(&mphy->dev->mutex);
+	return ret;
+}
+
+static const struct file_operations fops_set_rate_override = {
+	.read = mt7915_read_set_rate_override,
+	.write = mt7915_write_set_rate_override,
+	.open = simple_open,
+	.owner = THIS_MODULE,
+	.llseek = default_llseek,
+};
+
 static int
 mt7915_txs_for_no_skb_set(void *data, u64 val)
 {
@@ -577,6 +799,8 @@ int mt7915_init_debugfs(struct mt7915_phy *phy)
 		debugfs_create_file("radar_trigger", 0200, dir, dev,
 				    &fops_radar_trigger);
 	}
+	debugfs_create_file("set_rate_override", 0600, dir,
+			    dev, &fops_set_rate_override);
 
 	return 0;
 }