From 2cd5485663847d468dc207b3ff85fb1fab44d97f Mon Sep 17 00:00:00 2001 From: Ansuel Smith Date: Wed, 2 Feb 2022 01:03:31 +0100 Subject: [PATCH 12/16] 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: Ansuel Smith Signed-off-by: David S. Miller --- drivers/net/dsa/qca8k.c | 216 ++++++++++++++++++++++++++++++++++++++++ drivers/net/dsa/qca8k.h | 1 + 2 files changed, 217 insertions(+) --- a/drivers/net/dsa/qca8k.c +++ b/drivers/net/dsa/qca8k.c @@ -867,6 +867,199 @@ qca8k_port_set_status(struct qca8k_priv 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 { 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 { 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, i 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, in 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) --- a/drivers/net/dsa/qca8k.h +++ b/drivers/net/dsa/qca8k.h @@ -14,6 +14,7 @@ #include #define QCA8K_ETHERNET_MDIO_PRIORITY 7 +#define QCA8K_ETHERNET_PHY_PRIORITY 6 #define QCA8K_ETHERNET_TIMEOUT 100 #define QCA8K_NUM_PORTS 7