[PATCH v2 15/17] soc: fsl: cpm1: qmc: Handle timeslot entries at channel start() and stop()

[Herve Codina]

In order to support runtime timeslot route changes, enable the
channel timeslot entries at channel start() and disable them at
channel stop().

Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx>
Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
 drivers/soc/fsl/qe/qmc.c | 241 +++++++++++++++++++++++++++++++--------
 1 file changed, 195 insertions(+), 46 deletions(-)

diff --git a/drivers/soc/fsl/qe/qmc.c b/drivers/soc/fsl/qe/qmc.c
index e651b3bba1ca..bc72c1bc0ec4 100644
--- a/drivers/soc/fsl/qe/qmc.c
+++ b/drivers/soc/fsl/qe/qmc.c
@@ -177,6 +177,7 @@ struct qmc_chan {
 	struct qmc *qmc;
 	void __iomem *s_param;
 	enum qmc_mode mode;
+	spinlock_t	ts_lock; /* Protect timeslots */
 	u64	tx_ts_mask_avail;
 	u64	tx_ts_mask;
 	u64	rx_ts_mask_avail;
@@ -265,6 +266,7 @@ static void qmc_setbits32(void __iomem *addr, u32 set)
 int qmc_chan_get_info(struct qmc_chan *chan, struct qmc_chan_info *info)
 {
 	struct tsa_serial_info tsa_info;
+	unsigned long flags;
 	int ret;
 
 	/* Retrieve info from the TSA related serial */
@@ -272,6 +274,8 @@ int qmc_chan_get_info(struct qmc_chan *chan, struct qmc_chan_info *info)
 	if (ret)
 		return ret;
 
+	spin_lock_irqsave(&chan->ts_lock, flags);
+
 	info->mode = chan->mode;
 	info->rx_fs_rate = tsa_info.rx_fs_rate;
 	info->rx_bit_rate = tsa_info.rx_bit_rate;
@@ -280,6 +284,8 @@ int qmc_chan_get_info(struct qmc_chan *chan, struct qmc_chan_info *info)
 	info->tx_bit_rate = tsa_info.tx_bit_rate;
 	info->nb_rx_ts = hweight64(chan->rx_ts_mask);
 
+	spin_unlock_irqrestore(&chan->ts_lock, flags);
+
 	return 0;
 }
 EXPORT_SYMBOL(qmc_chan_get_info);
@@ -683,6 +689,40 @@ static int qmc_chan_setup_tsa_32tx(struct qmc_chan *chan, const struct tsa_seria
 	return 0;
 }
 
+static int qmc_chan_setup_tsa_tx(struct qmc_chan *chan, bool enable)
+{
+	struct tsa_serial_info info;
+	int ret;
+
+	/* Retrieve info from the TSA related serial */
+	ret = tsa_serial_get_info(chan->qmc->tsa_serial, &info);
+	if (ret)
+		return ret;
+
+	/* Setup entries */
+	if (chan->qmc->is_tsa_64rxtx)
+		return qmc_chan_setup_tsa_64rxtx(chan, &info, enable);
+
+	return qmc_chan_setup_tsa_32tx(chan, &info, enable);
+}
+
+static int qmc_chan_setup_tsa_rx(struct qmc_chan *chan, bool enable)
+{
+	struct tsa_serial_info info;
+	int ret;
+
+	/* Retrieve info from the TSA related serial */
+	ret = tsa_serial_get_info(chan->qmc->tsa_serial, &info);
+	if (ret)
+		return ret;
+
+	/* Setup entries */
+	if (chan->qmc->is_tsa_64rxtx)
+		return qmc_chan_setup_tsa_64rxtx(chan, &info, enable);
+
+	return qmc_chan_setup_tsa_32rx(chan, &info, enable);
+}
+
 static int qmc_chan_setup_tsa(struct qmc_chan *chan, bool enable)
 {
 	struct tsa_serial_info info;
@@ -719,6 +759,12 @@ static int qmc_chan_stop_rx(struct qmc_chan *chan)
 
 	spin_lock_irqsave(&chan->rx_lock, flags);
 
+	if (chan->is_rx_stopped) {
+		/* The channel is already stopped -> simply return ok */
+		ret = 0;
+		goto end;
+	}
+
 	/* Send STOP RECEIVE command */
 	ret = qmc_chan_command(chan, 0x0);
 	if (ret) {
@@ -729,6 +775,15 @@ static int qmc_chan_stop_rx(struct qmc_chan *chan)
 
 	chan->is_rx_stopped = true;
 
+	if (!chan->qmc->is_tsa_64rxtx || chan->is_tx_stopped) {
+		ret = qmc_chan_setup_tsa_rx(chan, false);
+		if (ret) {
+			dev_err(chan->qmc->dev, "chan %u: Disable tsa entries failed (%d)\n",
+				chan->id, ret);
+			goto end;
+		}
+	}
+
 end:
 	spin_unlock_irqrestore(&chan->rx_lock, flags);
 	return ret;
@@ -741,6 +796,12 @@ static int qmc_chan_stop_tx(struct qmc_chan *chan)
 
 	spin_lock_irqsave(&chan->tx_lock, flags);
 
+	if (chan->is_tx_stopped) {
+		/* The channel is already stopped -> simply return ok */
+		ret = 0;
+		goto end;
+	}
+
 	/* Send STOP TRANSMIT command */
 	ret = qmc_chan_command(chan, 0x1);
 	if (ret) {
@@ -751,37 +812,114 @@ static int qmc_chan_stop_tx(struct qmc_chan *chan)
 
 	chan->is_tx_stopped = true;
 
+	if (!chan->qmc->is_tsa_64rxtx || chan->is_rx_stopped) {
+		ret = qmc_chan_setup_tsa_tx(chan, false);
+		if (ret) {
+			dev_err(chan->qmc->dev, "chan %u: Disable tsa entries failed (%d)\n",
+				chan->id, ret);
+			goto end;
+		}
+	}
+
 end:
 	spin_unlock_irqrestore(&chan->tx_lock, flags);
 	return ret;
 }
 
+static int qmc_chan_start_rx(struct qmc_chan *chan);
+
 int qmc_chan_stop(struct qmc_chan *chan, int direction)
 {
-	int ret;
+	bool is_rx_rollback_needed = false;
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&chan->ts_lock, flags);
 
 	if (direction & QMC_CHAN_READ) {
+		is_rx_rollback_needed = !chan->is_rx_stopped;
 		ret = qmc_chan_stop_rx(chan);
 		if (ret)
-			return ret;
+			goto end;
 	}
 
 	if (direction & QMC_CHAN_WRITE) {
 		ret = qmc_chan_stop_tx(chan);
-		if (ret)
-			return ret;
+		if (ret) {
+			/* Restart rx if needed */
+			if (is_rx_rollback_needed)
+				qmc_chan_start_rx(chan);
+			goto end;
+		}
 	}
 
-	return 0;
+end:
+	spin_unlock_irqrestore(&chan->ts_lock, flags);
+	return ret;
 }
 EXPORT_SYMBOL(qmc_chan_stop);
 
-static void qmc_chan_start_rx(struct qmc_chan *chan)
+static int qmc_setup_chan_trnsync(struct qmc *qmc, struct qmc_chan *chan)
+{
+	struct tsa_serial_info info;
+	u16 first_rx, last_tx;
+	u16 trnsync;
+	int ret;
+
+	/* Retrieve info from the TSA related serial */
+	ret = tsa_serial_get_info(chan->qmc->tsa_serial, &info);
+	if (ret)
+		return ret;
+
+	/* Find the first Rx TS allocated to the channel */
+	first_rx = chan->rx_ts_mask ? __ffs64(chan->rx_ts_mask) + 1 : 0;
+
+	/* Find the last Tx TS allocated to the channel */
+	last_tx = fls64(chan->tx_ts_mask);
+
+	trnsync = 0;
+	if (info.nb_rx_ts)
+		trnsync |= QMC_SPE_TRNSYNC_RX((first_rx % info.nb_rx_ts) * 2);
+	if (info.nb_tx_ts)
+		trnsync |= QMC_SPE_TRNSYNC_TX((last_tx % info.nb_tx_ts) * 2);
+
+	qmc_write16(chan->s_param + QMC_SPE_TRNSYNC, trnsync);
+
+	dev_dbg(qmc->dev, "chan %u: trnsync=0x%04x, rx %u/%u 0x%llx, tx %u/%u 0x%llx\n",
+		chan->id, trnsync,
+		first_rx, info.nb_rx_ts, chan->rx_ts_mask,
+		last_tx, info.nb_tx_ts, chan->tx_ts_mask);
+
+	return 0;
+}
+
+static int qmc_chan_start_rx(struct qmc_chan *chan)
 {
 	unsigned long flags;
+	int ret;
 
 	spin_lock_irqsave(&chan->rx_lock, flags);
 
+	if (!chan->is_rx_stopped) {
+		/* The channel is already started -> simply return ok */
+		ret = 0;
+		goto end;
+	}
+
+	ret = qmc_chan_setup_tsa_rx(chan, true);
+	if (ret) {
+		dev_err(chan->qmc->dev, "chan %u: Enable tsa entries failed (%d)\n",
+			chan->id, ret);
+		goto end;
+	}
+
+	ret = qmc_setup_chan_trnsync(chan->qmc, chan);
+	if (ret) {
+		dev_err(chan->qmc->dev, "chan %u: setup TRNSYNC failed (%d)\n",
+			chan->id, ret);
+		goto end;
+	}
+
 	/* Restart the receiver */
 	if (chan->mode == QMC_TRANSPARENT)
 		qmc_write32(chan->s_param + QMC_SPE_ZDSTATE, 0x18000080);
@@ -792,15 +930,38 @@ static void qmc_chan_start_rx(struct qmc_chan *chan)
 
 	chan->is_rx_stopped = false;
 
+end:
 	spin_unlock_irqrestore(&chan->rx_lock, flags);
+	return ret;
 }
 
-static void qmc_chan_start_tx(struct qmc_chan *chan)
+static int qmc_chan_start_tx(struct qmc_chan *chan)
 {
 	unsigned long flags;
+	int ret;
 
 	spin_lock_irqsave(&chan->tx_lock, flags);
 
+	if (!chan->is_tx_stopped) {
+		/* The channel is already started -> simply return ok */
+		ret = 0;
+		goto end;
+	}
+
+	ret = qmc_chan_setup_tsa_tx(chan, true);
+	if (ret) {
+		dev_err(chan->qmc->dev, "chan %u: Enable tsa entries failed (%d)\n",
+			chan->id, ret);
+		goto end;
+	}
+
+	ret = qmc_setup_chan_trnsync(chan->qmc, chan);
+	if (ret) {
+		dev_err(chan->qmc->dev, "chan %u: setup TRNSYNC failed (%d)\n",
+			chan->id, ret);
+		goto end;
+	}
+
 	/*
 	 * Enable channel transmitter as it could be disabled if
 	 * qmc_chan_reset() was called.
@@ -812,18 +973,39 @@ static void qmc_chan_start_tx(struct qmc_chan *chan)
 
 	chan->is_tx_stopped = false;
 
+end:
 	spin_unlock_irqrestore(&chan->tx_lock, flags);
+	return ret;
 }
 
 int qmc_chan_start(struct qmc_chan *chan, int direction)
 {
-	if (direction & QMC_CHAN_READ)
-		qmc_chan_start_rx(chan);
+	bool is_rx_rollback_needed = false;
+	unsigned long flags;
+	int ret = 0;
 
-	if (direction & QMC_CHAN_WRITE)
-		qmc_chan_start_tx(chan);
+	spin_lock_irqsave(&chan->ts_lock, flags);
 
-	return 0;
+	if (direction & QMC_CHAN_READ) {
+		is_rx_rollback_needed = chan->is_rx_stopped;
+		ret = qmc_chan_start_rx(chan);
+		if (ret)
+			goto end;
+	}
+
+	if (direction & QMC_CHAN_WRITE) {
+		ret = qmc_chan_start_tx(chan);
+		if (ret) {
+			/* Restop rx if needed */
+			if (is_rx_rollback_needed)
+				qmc_chan_stop_rx(chan);
+			goto end;
+		}
+	}
+
+end:
+	spin_unlock_irqrestore(&chan->ts_lock, flags);
+	return ret;
 }
 EXPORT_SYMBOL(qmc_chan_start);
 
@@ -992,6 +1174,7 @@ static int qmc_of_parse_chans(struct qmc *qmc, struct device_node *np)
 		}
 
 		chan->id = chan_id;
+		spin_lock_init(&chan->ts_lock);
 		spin_lock_init(&chan->rx_lock);
 		spin_lock_init(&chan->tx_lock);
 
@@ -1129,40 +1312,6 @@ static int qmc_init_tsa(struct qmc *qmc)
 		qmc_init_tsa_32rx_32tx(qmc, &info);
 }
 
-static int qmc_setup_chan_trnsync(struct qmc *qmc, struct qmc_chan *chan)
-{
-	struct tsa_serial_info info;
-	u16 first_rx, last_tx;
-	u16 trnsync;
-	int ret;
-
-	/* Retrieve info from the TSA related serial */
-	ret = tsa_serial_get_info(chan->qmc->tsa_serial, &info);
-	if (ret)
-		return ret;
-
-	/* Find the first Rx TS allocated to the channel */
-	first_rx = chan->rx_ts_mask ? __ffs64(chan->rx_ts_mask) + 1 : 0;
-
-	/* Find the last Tx TS allocated to the channel */
-	last_tx = fls64(chan->tx_ts_mask);
-
-	trnsync = 0;
-	if (info.nb_rx_ts)
-		trnsync |= QMC_SPE_TRNSYNC_RX((first_rx % info.nb_rx_ts) * 2);
-	if (info.nb_tx_ts)
-		trnsync |= QMC_SPE_TRNSYNC_TX((last_tx % info.nb_tx_ts) * 2);
-
-	qmc_write16(chan->s_param + QMC_SPE_TRNSYNC, trnsync);
-
-	dev_dbg(qmc->dev, "chan %u: trnsync=0x%04x, rx %u/%u 0x%llx, tx %u/%u 0x%llx\n",
-		chan->id, trnsync,
-		first_rx, info.nb_rx_ts, chan->rx_ts_mask,
-		last_tx, info.nb_tx_ts, chan->tx_ts_mask);
-
-	return 0;
-}
-
 static int qmc_setup_chan(struct qmc *qmc, struct qmc_chan *chan)
 {
 	unsigned int i;
-- 
2.43.0