Commit 2cd54856 authored by Ansuel Smith's avatar Ansuel Smith Committed by David S. Miller
Browse files

net: dsa: qca8k: add support for phy read/write with mgmt Ethernet 



Use mgmt Ethernet also for phy read/write if availabale. Use a different
seq number to make sure we receive the correct packet.
On any error, we fallback to the legacy mdio read/write.

Signed-off-by: default avatarAnsuel Smith <ansuelsmth@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5c957c7c

drivers/net/dsa/qca8k.c

+216 −0
Original line number Diff line number Diff line
@@ -867,6 +867,199 @@ qca8k_port_set_status(struct qca8k_priv *priv, int port, int enable) 
		regmap_clear_bits(priv->regmap, QCA8K_REG_PORT_STATUS(port), mask);

}



static int

qca8k_phy_eth_busy_wait(struct qca8k_mgmt_eth_data *mgmt_eth_data,

			struct sk_buff *read_skb, u32 *val)

{

	struct sk_buff *skb = skb_copy(read_skb, GFP_KERNEL);

	bool ack;

	int ret;



	reinit_completion(&mgmt_eth_data->rw_done);



	/* Increment seq_num and set it in the copy pkt */

	mgmt_eth_data->seq++;

	qca8k_mdio_header_fill_seq_num(skb, mgmt_eth_data->seq);

	mgmt_eth_data->ack = false;



	dev_queue_xmit(skb);



	ret = wait_for_completion_timeout(&mgmt_eth_data->rw_done,

					  QCA8K_ETHERNET_TIMEOUT);



	ack = mgmt_eth_data->ack;



	if (ret <= 0)

		return -ETIMEDOUT;



	if (!ack)

		return -EINVAL;



	*val = mgmt_eth_data->data[0];



	return 0;

}



static int

qca8k_phy_eth_command(struct qca8k_priv *priv, bool read, int phy,

		      int regnum, u16 data)

{

	struct sk_buff *write_skb, *clear_skb, *read_skb;

	struct qca8k_mgmt_eth_data *mgmt_eth_data;

	u32 write_val, clear_val = 0, val;

	struct net_device *mgmt_master;

	int ret, ret1;

	bool ack;



	if (regnum >= QCA8K_MDIO_MASTER_MAX_REG)

		return -EINVAL;



	mgmt_eth_data = &priv->mgmt_eth_data;



	write_val = QCA8K_MDIO_MASTER_BUSY | QCA8K_MDIO_MASTER_EN |

		    QCA8K_MDIO_MASTER_PHY_ADDR(phy) |

		    QCA8K_MDIO_MASTER_REG_ADDR(regnum);



	if (read) {

		write_val |= QCA8K_MDIO_MASTER_READ;

	} else {

		write_val |= QCA8K_MDIO_MASTER_WRITE;

		write_val |= QCA8K_MDIO_MASTER_DATA(data);

	}



	/* Prealloc all the needed skb before the lock */

	write_skb = qca8k_alloc_mdio_header(MDIO_WRITE, QCA8K_MDIO_MASTER_CTRL,

					    &write_val, QCA8K_ETHERNET_PHY_PRIORITY);

	if (!write_skb)

		return -ENOMEM;



	clear_skb = qca8k_alloc_mdio_header(MDIO_WRITE, QCA8K_MDIO_MASTER_CTRL,

					    &clear_val, QCA8K_ETHERNET_PHY_PRIORITY);

	if (!write_skb) {

		ret = -ENOMEM;

		goto err_clear_skb;

	}



	read_skb = qca8k_alloc_mdio_header(MDIO_READ, QCA8K_MDIO_MASTER_CTRL,

					   &clear_val, QCA8K_ETHERNET_PHY_PRIORITY);

	if (!write_skb) {

		ret = -ENOMEM;

		goto err_read_skb;

	}



	/* Actually start the request:

	 * 1. Send mdio master packet

	 * 2. Busy Wait for mdio master command

	 * 3. Get the data if we are reading

	 * 4. Reset the mdio master (even with error)

	 */

	mutex_lock(&mgmt_eth_data->mutex);



	/* Check if mgmt_master is operational */

	mgmt_master = priv->mgmt_master;

	if (!mgmt_master) {

		mutex_unlock(&mgmt_eth_data->mutex);

		ret = -EINVAL;

		goto err_mgmt_master;

	}



	read_skb->dev = mgmt_master;

	clear_skb->dev = mgmt_master;

	write_skb->dev = mgmt_master;



	reinit_completion(&mgmt_eth_data->rw_done);



	/* Increment seq_num and set it in the write pkt */

	mgmt_eth_data->seq++;

	qca8k_mdio_header_fill_seq_num(write_skb, mgmt_eth_data->seq);

	mgmt_eth_data->ack = false;



	dev_queue_xmit(write_skb);



	ret = wait_for_completion_timeout(&mgmt_eth_data->rw_done,

					  QCA8K_ETHERNET_TIMEOUT);



	ack = mgmt_eth_data->ack;



	if (ret <= 0) {

		ret = -ETIMEDOUT;

		kfree_skb(read_skb);

		goto exit;

	}



	if (!ack) {

		ret = -EINVAL;

		kfree_skb(read_skb);

		goto exit;

	}



	ret = read_poll_timeout(qca8k_phy_eth_busy_wait, ret1,

				!(val & QCA8K_MDIO_MASTER_BUSY), 0,

				QCA8K_BUSY_WAIT_TIMEOUT * USEC_PER_MSEC, false,

				mgmt_eth_data, read_skb, &val);



	if (ret < 0 && ret1 < 0) {

		ret = ret1;

		goto exit;

	}



	if (read) {

		reinit_completion(&mgmt_eth_data->rw_done);



		/* Increment seq_num and set it in the read pkt */

		mgmt_eth_data->seq++;

		qca8k_mdio_header_fill_seq_num(read_skb, mgmt_eth_data->seq);

		mgmt_eth_data->ack = false;



		dev_queue_xmit(read_skb);



		ret = wait_for_completion_timeout(&mgmt_eth_data->rw_done,

						  QCA8K_ETHERNET_TIMEOUT);



		ack = mgmt_eth_data->ack;



		if (ret <= 0) {

			ret = -ETIMEDOUT;

			goto exit;

		}



		if (!ack) {

			ret = -EINVAL;

			goto exit;

		}



		ret = mgmt_eth_data->data[0] & QCA8K_MDIO_MASTER_DATA_MASK;

	} else {

		kfree_skb(read_skb);

	}

exit:

	reinit_completion(&mgmt_eth_data->rw_done);



	/* Increment seq_num and set it in the clear pkt */

	mgmt_eth_data->seq++;

	qca8k_mdio_header_fill_seq_num(clear_skb, mgmt_eth_data->seq);

	mgmt_eth_data->ack = false;



	dev_queue_xmit(clear_skb);



	wait_for_completion_timeout(&mgmt_eth_data->rw_done,

				    QCA8K_ETHERNET_TIMEOUT);



	mutex_unlock(&mgmt_eth_data->mutex);



	return ret;



	/* Error handling before lock */

err_mgmt_master:

	kfree_skb(read_skb);

err_read_skb:

	kfree_skb(clear_skb);

err_clear_skb:

	kfree_skb(write_skb);



	return ret;

}



static u32

qca8k_port_to_phy(int port)

{
@@ -989,6 +1182,12 @@ qca8k_internal_mdio_write(struct mii_bus *slave_bus, int phy, int regnum, u16 da 
{

	struct qca8k_priv *priv = slave_bus->priv;

	struct mii_bus *bus = priv->bus;

	int ret;



	/* Use mdio Ethernet when available, fallback to legacy one on error */

	ret = qca8k_phy_eth_command(priv, false, phy, regnum, data);

	if (!ret)

		return 0;



	return qca8k_mdio_write(bus, phy, regnum, data);

}
@@ -998,6 +1197,12 @@ qca8k_internal_mdio_read(struct mii_bus *slave_bus, int phy, int regnum) 
{

	struct qca8k_priv *priv = slave_bus->priv;

	struct mii_bus *bus = priv->bus;

	int ret;



	/* Use mdio Ethernet when available, fallback to legacy one on error */

	ret = qca8k_phy_eth_command(priv, true, phy, regnum, 0);

	if (ret >= 0)

		return ret;



	return qca8k_mdio_read(bus, phy, regnum);

}
@@ -1006,6 +1211,7 @@ static int 
qca8k_phy_write(struct dsa_switch *ds, int port, int regnum, u16 data)

{

	struct qca8k_priv *priv = ds->priv;

	int ret;



	/* Check if the legacy mapping should be used and the

	 * port is not correctly mapped to the right PHY in the
@@ -1014,6 +1220,11 @@ qca8k_phy_write(struct dsa_switch *ds, int port, int regnum, u16 data) 
	if (priv->legacy_phy_port_mapping)

		port = qca8k_port_to_phy(port) % PHY_MAX_ADDR;



	/* Use mdio Ethernet when available, fallback to legacy one on error */

	ret = qca8k_phy_eth_command(priv, false, port, regnum, 0);

	if (!ret)

		return ret;



	return qca8k_mdio_write(priv->bus, port, regnum, data);

}
@@ -1030,6 +1241,11 @@ qca8k_phy_read(struct dsa_switch *ds, int port, int regnum) 
	if (priv->legacy_phy_port_mapping)

		port = qca8k_port_to_phy(port) % PHY_MAX_ADDR;



	/* Use mdio Ethernet when available, fallback to legacy one on error */

	ret = qca8k_phy_eth_command(priv, true, port, regnum, 0);

	if (ret >= 0)

		return ret;



	ret = qca8k_mdio_read(priv->bus, port, regnum);



	if (ret < 0)

drivers/net/dsa/qca8k.h

+1 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/dsa/tag_qca.h>



#define QCA8K_ETHERNET_MDIO_PRIORITY			7

#define QCA8K_ETHERNET_PHY_PRIORITY			6

#define QCA8K_ETHERNET_TIMEOUT				100



#define QCA8K_NUM_PORTS					7