Re: [PATCH v2 16/28] soc: fsl: cpm1: qmc: Handle timeslot entries at channel start() and stop()

[Christophe Leroy <christophe.leroy@xxxxxxxxxx>]

Le 26/07/2023 à 17:02, Herve Codina a écrit :
> 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 | 175 ++++++++++++++++++++++++++++++++++++---
>   1 file changed, 163 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/soc/fsl/qe/qmc.c b/drivers/soc/fsl/qe/qmc.c
> index dc113463fbc7..258a34641551 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 inline 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 +812,82 @@ 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);
> +
> +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 +898,38 @@ 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 +941,39 @@ 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 +1142,7 @@ 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);
>