net: bcmgenet: add MDIO routines
authorFlorian Fainelli <f.fainelli@gmail.com>
Fri, 14 Feb 2014 00:08:48 +0000 (16:08 -0800)
committerDavid S. Miller <davem@davemloft.net>
Fri, 14 Feb 2014 05:27:58 +0000 (00:27 -0500)
This patch adds support for configuring the port multiplexer hardware
which resides in front of the GENET Ethernet MAC controller. This allows
us to support:

- internal PHYs (using drivers/net/phy/bcm7xxx.c)
- MoCA PHYs which are an entirely separate hardware block not covered
  here
- external PHYs and switches

Note that MoCA and switches are currently supported using the emulated
"fixed PHY" driver.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/broadcom/genet/bcmmii.c [new file with mode: 0644]

diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
new file mode 100644 (file)
index 0000000..4608673
--- /dev/null
@@ -0,0 +1,464 @@
+/*
+ * Broadcom GENET MDIO routines
+ *
+ * Copyright (c) 2014 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/wait.h>
+#include <linux/mii.h>
+#include <linux/ethtool.h>
+#include <linux/bitops.h>
+#include <linux/netdevice.h>
+#include <linux/platform_device.h>
+#include <linux/phy.h>
+#include <linux/phy_fixed.h>
+#include <linux/brcmphy.h>
+#include <linux/of.h>
+#include <linux/of_net.h>
+#include <linux/of_mdio.h>
+
+#include "bcmgenet.h"
+
+/* read a value from the MII */
+static int bcmgenet_mii_read(struct mii_bus *bus, int phy_id, int location)
+{
+       int ret;
+       struct net_device *dev = bus->priv;
+       struct bcmgenet_priv *priv = netdev_priv(dev);
+       u32 reg;
+
+       bcmgenet_umac_writel(priv, (MDIO_RD | (phy_id << MDIO_PMD_SHIFT) |
+                       (location << MDIO_REG_SHIFT)), UMAC_MDIO_CMD);
+       /* Start MDIO transaction*/
+       reg = bcmgenet_umac_readl(priv, UMAC_MDIO_CMD);
+       reg |= MDIO_START_BUSY;
+       bcmgenet_umac_writel(priv, reg, UMAC_MDIO_CMD);
+       wait_event_timeout(priv->wq,
+                       !(bcmgenet_umac_readl(priv, UMAC_MDIO_CMD)
+                               & MDIO_START_BUSY),
+                       HZ / 100);
+       ret = bcmgenet_umac_readl(priv, UMAC_MDIO_CMD);
+
+       if (ret & MDIO_READ_FAIL)
+               return -EIO;
+
+       return ret & 0xffff;
+}
+
+/* write a value to the MII */
+static int bcmgenet_mii_write(struct mii_bus *bus, int phy_id,
+                       int location, u16 val)
+{
+       struct net_device *dev = bus->priv;
+       struct bcmgenet_priv *priv = netdev_priv(dev);
+       u32 reg;
+
+       bcmgenet_umac_writel(priv, (MDIO_WR | (phy_id << MDIO_PMD_SHIFT) |
+                       (location << MDIO_REG_SHIFT) | (0xffff & val)),
+                       UMAC_MDIO_CMD);
+       reg = bcmgenet_umac_readl(priv, UMAC_MDIO_CMD);
+       reg |= MDIO_START_BUSY;
+       bcmgenet_umac_writel(priv, reg, UMAC_MDIO_CMD);
+       wait_event_timeout(priv->wq,
+                       !(bcmgenet_umac_readl(priv, UMAC_MDIO_CMD) &
+                               MDIO_START_BUSY),
+                       HZ / 100);
+
+       return 0;
+}
+
+/* setup netdev link state when PHY link status change and
+ * update UMAC and RGMII block when link up
+ */
+static void bcmgenet_mii_setup(struct net_device *dev)
+{
+       struct bcmgenet_priv *priv = netdev_priv(dev);
+       struct phy_device *phydev = priv->phydev;
+       u32 reg, cmd_bits = 0;
+       unsigned int status_changed = 0;
+
+       if (priv->old_link != phydev->link) {
+               status_changed = 1;
+               priv->old_link = phydev->link;
+       }
+
+       if (phydev->link) {
+               /* program UMAC and RGMII block based on established link
+                * speed, pause, and duplex.
+                * the speed set in umac->cmd tell RGMII block which clock
+                * 25MHz(100Mbps)/125MHz(1Gbps) to use for transmit.
+                * receive clock is provided by PHY.
+                */
+               reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL);
+               reg &= ~OOB_DISABLE;
+               reg |= RGMII_LINK;
+               bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL);
+
+               /* speed */
+               if (phydev->speed == SPEED_1000)
+                       cmd_bits = UMAC_SPEED_1000;
+               else if (phydev->speed == SPEED_100)
+                       cmd_bits = UMAC_SPEED_100;
+               else
+                       cmd_bits = UMAC_SPEED_10;
+               cmd_bits <<= CMD_SPEED_SHIFT;
+
+               if (priv->old_duplex != phydev->duplex) {
+                       status_changed = 1;
+                       priv->old_duplex = phydev->duplex;
+               }
+
+               /* duplex */
+               if (phydev->duplex != DUPLEX_FULL)
+                       cmd_bits |= CMD_HD_EN;
+
+               if (priv->old_pause != phydev->pause) {
+                       status_changed = 1;
+                       priv->old_pause = phydev->pause;
+               }
+
+               /* pause capability */
+               if (!phydev->pause)
+                       cmd_bits |= CMD_RX_PAUSE_IGNORE | CMD_TX_PAUSE_IGNORE;
+
+               reg = bcmgenet_umac_readl(priv, UMAC_CMD);
+               reg &= ~((CMD_SPEED_MASK << CMD_SPEED_SHIFT) |
+                              CMD_HD_EN |
+                              CMD_RX_PAUSE_IGNORE | CMD_TX_PAUSE_IGNORE);
+               reg |= cmd_bits;
+               bcmgenet_umac_writel(priv, reg, UMAC_CMD);
+       }
+
+       if (status_changed)
+               phy_print_status(phydev);
+}
+
+void bcmgenet_mii_reset(struct net_device *dev)
+{
+       struct bcmgenet_priv *priv = netdev_priv(dev);
+
+       if (priv->phydev) {
+               phy_init_hw(priv->phydev);
+               phy_start_aneg(priv->phydev);
+       }
+}
+
+static void bcmgenet_ephy_power_up(struct net_device *dev)
+{
+       struct bcmgenet_priv *priv = netdev_priv(dev);
+       u32 reg = 0;
+
+       /* EXT_GPHY_CTRL is only valid for GENETv4 and onward */
+       if (!GENET_IS_V4(priv))
+               return;
+
+       reg = bcmgenet_ext_readl(priv, EXT_GPHY_CTRL);
+       reg &= ~(EXT_CFG_IDDQ_BIAS | EXT_CFG_PWR_DOWN);
+       reg |= EXT_GPHY_RESET;
+       bcmgenet_ext_writel(priv, reg, EXT_GPHY_CTRL);
+       mdelay(2);
+
+       reg &= ~EXT_GPHY_RESET;
+       bcmgenet_ext_writel(priv, reg, EXT_GPHY_CTRL);
+       udelay(20);
+}
+
+static void bcmgenet_internal_phy_setup(struct net_device *dev)
+{
+       struct bcmgenet_priv *priv = netdev_priv(dev);
+       u32 reg;
+
+       /* Power up EPHY */
+       bcmgenet_ephy_power_up(dev);
+       /* enable APD */
+       reg = bcmgenet_ext_readl(priv, EXT_EXT_PWR_MGMT);
+       reg |= EXT_PWR_DN_EN_LD;
+       bcmgenet_ext_writel(priv, reg, EXT_EXT_PWR_MGMT);
+       bcmgenet_mii_reset(dev);
+}
+
+static void bcmgenet_moca_phy_setup(struct bcmgenet_priv *priv)
+{
+       u32 reg;
+
+       /* Speed settings are set in bcmgenet_mii_setup() */
+       reg = bcmgenet_sys_readl(priv, SYS_PORT_CTRL);
+       reg |= LED_ACT_SOURCE_MAC;
+       bcmgenet_sys_writel(priv, reg, SYS_PORT_CTRL);
+}
+
+int bcmgenet_mii_config(struct net_device *dev)
+{
+       struct bcmgenet_priv *priv = netdev_priv(dev);
+       struct phy_device *phydev = priv->phydev;
+       struct device *kdev = &priv->pdev->dev;
+       const char *phy_name = NULL;
+       u32 id_mode_dis = 0;
+       u32 port_ctrl;
+       u32 reg;
+
+       priv->ext_phy = !phy_is_internal(priv->phydev) &&
+                       (priv->phy_interface != PHY_INTERFACE_MODE_MOCA);
+
+       if (phy_is_internal(priv->phydev))
+               priv->phy_interface = PHY_INTERFACE_MODE_NA;
+
+       switch (priv->phy_interface) {
+       case PHY_INTERFACE_MODE_NA:
+       case PHY_INTERFACE_MODE_MOCA:
+               /* Irrespective of the actually configured PHY speed (100 or
+                * 1000) GENETv4 only has an internal GPHY so we will just end
+                * up masking the Gigabit features from what we support, not
+                * switching to the EPHY
+                */
+               if (GENET_IS_V4(priv))
+                       port_ctrl = PORT_MODE_INT_GPHY;
+               else
+                       port_ctrl = PORT_MODE_INT_EPHY;
+
+               bcmgenet_sys_writel(priv, port_ctrl, SYS_PORT_CTRL);
+
+               if (phy_is_internal(priv->phydev)) {
+                       phy_name = "internal PHY";
+                       bcmgenet_internal_phy_setup(dev);
+               } else if (priv->phy_interface == PHY_INTERFACE_MODE_MOCA) {
+                       phy_name = "MoCA";
+                       bcmgenet_moca_phy_setup(priv);
+               }
+               break;
+
+       case PHY_INTERFACE_MODE_MII:
+               phy_name = "external MII";
+               phydev->supported &= PHY_BASIC_FEATURES;
+               bcmgenet_sys_writel(priv,
+                               PORT_MODE_EXT_EPHY, SYS_PORT_CTRL);
+               break;
+
+       case PHY_INTERFACE_MODE_REVMII:
+               phy_name = "external RvMII";
+               /* of_mdiobus_register took care of reading the 'max-speed'
+                * PHY property for us, effectively limiting the PHY supported
+                * capabilities, use that knowledge to also configure the
+                * Reverse MII interface correctly.
+                */
+               if ((priv->phydev->supported & PHY_BASIC_FEATURES) ==
+                               PHY_BASIC_FEATURES)
+                       port_ctrl = PORT_MODE_EXT_RVMII_25;
+               else
+                       port_ctrl = PORT_MODE_EXT_RVMII_50;
+               bcmgenet_sys_writel(priv, port_ctrl, SYS_PORT_CTRL);
+               break;
+
+       case PHY_INTERFACE_MODE_RGMII:
+               /* RGMII_NO_ID: TXC transitions at the same time as TXD
+                *              (requires PCB or receiver-side delay)
+                * RGMII:       Add 2ns delay on TXC (90 degree shift)
+                *
+                * ID is implicitly disabled for 100Mbps (RG)MII operation.
+                */
+               id_mode_dis = BIT(16);
+               /* fall through */
+       case PHY_INTERFACE_MODE_RGMII_TXID:
+               if (id_mode_dis)
+                       phy_name = "external RGMII (no delay)";
+               else
+                       phy_name = "external RGMII (TX delay)";
+               reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL);
+               reg |= RGMII_MODE_EN | id_mode_dis;
+               bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL);
+               bcmgenet_sys_writel(priv,
+                               PORT_MODE_EXT_GPHY, SYS_PORT_CTRL);
+               break;
+       default:
+               dev_err(kdev, "unknown phy mode: %d\n", priv->phy_interface);
+               return -EINVAL;
+       }
+
+       dev_info(kdev, "configuring instance for %s\n", phy_name);
+
+       return 0;
+}
+
+static int bcmgenet_mii_probe(struct net_device *dev)
+{
+       struct bcmgenet_priv *priv = netdev_priv(dev);
+       struct phy_device *phydev;
+       unsigned int phy_flags;
+       int ret;
+
+       if (priv->phydev) {
+               pr_info("PHY already attached\n");
+               return 0;
+       }
+
+       if (priv->phy_dn)
+               phydev = of_phy_connect(dev, priv->phy_dn,
+                                       bcmgenet_mii_setup, 0,
+                                       priv->phy_interface);
+       else
+               phydev = of_phy_connect_fixed_link(dev,
+                                       bcmgenet_mii_setup,
+                                       priv->phy_interface);
+
+       if (!phydev) {
+               pr_err("could not attach to PHY\n");
+               return -ENODEV;
+       }
+
+       priv->old_link = -1;
+       priv->old_duplex = -1;
+       priv->old_pause = -1;
+       priv->phydev = phydev;
+
+       /* Configure port multiplexer based on what the probed PHY device since
+        * reading the 'max-speed' property determines the maximum supported
+        * PHY speed which is needed for bcmgenet_mii_config() to configure
+        * things appropriately.
+        */
+       ret = bcmgenet_mii_config(dev);
+       if (ret) {
+               phy_disconnect(priv->phydev);
+               return ret;
+       }
+
+       phy_flags = PHY_BRCM_100MBPS_WAR;
+
+       /* workarounds are only needed for 100Mpbs PHYs, and
+        * never on GENET V1 hardware
+        */
+       if ((phydev->supported & PHY_GBIT_FEATURES) || GENET_IS_V1(priv))
+               phy_flags = 0;
+
+       phydev->dev_flags |= phy_flags;
+       phydev->advertising = phydev->supported;
+
+       /* The internal PHY has its link interrupts routed to the
+        * Ethernet MAC ISRs
+        */
+       if (phy_is_internal(priv->phydev))
+               priv->mii_bus->irq[phydev->addr] = PHY_IGNORE_INTERRUPT;
+       else
+               priv->mii_bus->irq[phydev->addr] = PHY_POLL;
+
+       pr_info("attached PHY at address %d [%s]\n",
+                       phydev->addr, phydev->drv->name);
+
+       return 0;
+}
+
+static int bcmgenet_mii_alloc(struct bcmgenet_priv *priv)
+{
+       struct mii_bus *bus;
+
+       if (priv->mii_bus)
+               return 0;
+
+       priv->mii_bus = mdiobus_alloc();
+       if (!priv->mii_bus) {
+               pr_err("failed to allocate\n");
+               return -ENOMEM;
+       }
+
+       bus = priv->mii_bus;
+       bus->priv = priv->dev;
+       bus->name = "bcmgenet MII bus";
+       bus->parent = &priv->pdev->dev;
+       bus->read = bcmgenet_mii_read;
+       bus->write = bcmgenet_mii_write;
+       snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d",
+                       priv->pdev->name, priv->pdev->id);
+
+       bus->irq = kzalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
+       if (!bus->irq) {
+               mdiobus_free(priv->mii_bus);
+               return -ENOMEM;
+       }
+
+       return 0;
+}
+
+static int bcmgenet_mii_of_init(struct bcmgenet_priv *priv)
+{
+       struct device_node *dn = priv->pdev->dev.of_node;
+       struct device *kdev = &priv->pdev->dev;
+       struct device_node *mdio_dn;
+       char *compat;
+       int ret;
+
+       compat = kasprintf(GFP_KERNEL, "brcm,genet-mdio-v%d", priv->version);
+       if (!compat)
+               return -ENOMEM;
+
+       mdio_dn = of_find_compatible_node(dn, NULL, compat);
+       kfree(compat);
+       if (!mdio_dn) {
+               dev_err(kdev, "unable to find MDIO bus node\n");
+               return -ENODEV;
+       }
+
+       ret = of_mdiobus_register(priv->mii_bus, mdio_dn);
+       if (ret) {
+               dev_err(kdev, "failed to register MDIO bus\n");
+               return ret;
+       }
+
+       /* Fetch the PHY phandle */
+       priv->phy_dn = of_parse_phandle(dn, "phy-handle", 0);
+
+       /* Get the link mode */
+       priv->phy_interface = of_get_phy_mode(dn);
+
+       return 0;
+}
+
+int bcmgenet_mii_init(struct net_device *dev)
+{
+       struct bcmgenet_priv *priv = netdev_priv(dev);
+       int ret;
+
+       ret = bcmgenet_mii_alloc(priv);
+       if (ret)
+               return ret;
+
+       ret = bcmgenet_mii_of_init(priv);
+       if (ret)
+               goto out_free;
+
+       ret = bcmgenet_mii_probe(dev);
+       if (ret)
+               goto out;
+
+       return 0;
+
+out:
+       mdiobus_unregister(priv->mii_bus);
+out_free:
+       kfree(priv->mii_bus->irq);
+       mdiobus_free(priv->mii_bus);
+       return ret;
+}
+
+void bcmgenet_mii_exit(struct net_device *dev)
+{
+       struct bcmgenet_priv *priv = netdev_priv(dev);
+
+       mdiobus_unregister(priv->mii_bus);
+       kfree(priv->mii_bus->irq);
+       mdiobus_free(priv->mii_bus);
+}