[PATCH v2 1/3] fec_phy: add new PHY file
From: Apeksha Gupta
Date: Sun Dec 05 2021 - 23:56:27 EST
Added common file for PHY related functions. Files fec_phy.h
and fec_phy.c have PHY related API's. Now whenever required,
FEC driver is able to work with other PHY drivers. Hence by
these changes making the FEC driver more flexible.
Signed-off-by: Sachin Saxena <sachin.saxena@xxxxxxx>
Signed-off-by: Apeksha Gupta <apeksha.gupta@xxxxxxx>
---
drivers/net/ethernet/freescale/Makefile | 4 +-
drivers/net/ethernet/freescale/fec_phy.c | 376 +++++++++++++++++++++++
drivers/net/ethernet/freescale/fec_phy.h | 31 ++
3 files changed, 410 insertions(+), 1 deletion(-)
create mode 100644 drivers/net/ethernet/freescale/fec_phy.c
create mode 100644 drivers/net/ethernet/freescale/fec_phy.h
diff --git a/drivers/net/ethernet/freescale/Makefile b/drivers/net/ethernet/freescale/Makefile
index de7b31842233..61d417694e0e 100644
--- a/drivers/net/ethernet/freescale/Makefile
+++ b/drivers/net/ethernet/freescale/Makefile
@@ -3,8 +3,10 @@
# Makefile for the Freescale network device drivers.
#
+common-objs := fec_phy.o
+
obj-$(CONFIG_FEC) += fec.o
-fec-objs :=fec_main.o fec_ptp.o
+fec-objs :=fec_main.o fec_ptp.o $(common-objs)
obj-$(CONFIG_FEC_MPC52xx) += fec_mpc52xx.o
ifeq ($(CONFIG_FEC_MPC52xx_MDIO),y)
diff --git a/drivers/net/ethernet/freescale/fec_phy.c b/drivers/net/ethernet/freescale/fec_phy.c
new file mode 100644
index 000000000000..af64015f93c3
--- /dev/null
+++ b/drivers/net/ethernet/freescale/fec_phy.c
@@ -0,0 +1,376 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 1997 Dan Malek (dmalek@xxxxxxx)
+ * Copyright 2000 Ericsson Radio Systems AB.
+ * Copyright 2001-2005 Greg Ungerer (gerg@xxxxxxxxxxxx)
+ * Copyright 2004-2006 Macq Electronique SA.
+ * Copyright 2010-2011 Freescale Semiconductor, Inc.
+ * Copyright 2021 NXP
+ */
+
+#include <linux/pm_runtime.h>
+#include <linux/netdevice.h>
+#include <linux/clk.h>
+#include <linux/mdio.h>
+#include <linux/phy.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#include <linux/of_mdio.h>
+#include <linux/of_net.h>
+
+#include "fec.h"
+#include "fec_phy.h"
+
+static int mii_cnt;
+
+#ifdef CONFIG_OF
+int fec_reset_phy(struct platform_device *pdev)
+{
+ int err, phy_reset;
+ bool active_high = false;
+ int msec = 1, phy_post_delay = 0;
+ struct device_node *np = pdev->dev.of_node;
+
+ if (!np)
+ return 0;
+
+ err = of_property_read_u32(np, "phy-reset-duration", &msec);
+ /* A sane reset duration should not be longer than 1s */
+ if (!err && msec > 1000)
+ msec = 1;
+
+ phy_reset = of_get_named_gpio(np, "phy-reset-gpios", 0);
+ if (phy_reset == -EPROBE_DEFER)
+ return phy_reset;
+ else if (!gpio_is_valid(phy_reset))
+ return 0;
+
+ err = of_property_read_u32(np, "phy-reset-post-delay", &phy_post_delay);
+ /* valid reset duration should be less than 1s */
+ if (!err && phy_post_delay > 1000)
+ return -EINVAL;
+
+ active_high = of_property_read_bool(np, "phy-reset-active-high");
+
+ err = devm_gpio_request_one(&pdev->dev, phy_reset,
+ active_high ? GPIOF_OUT_INIT_HIGH :
+ GPIOF_OUT_INIT_LOW, "phy-reset");
+ if (err) {
+ dev_err(&pdev->dev, "failed to get phy-reset-gpios: %d\n", err);
+ return err;
+ }
+
+ if (msec > 20)
+ msleep(msec);
+ else
+ usleep_range(msec * 1000, msec * 1000 + 1000);
+
+ gpio_set_value_cansleep(phy_reset, !active_high);
+
+ if (!phy_post_delay)
+ return 0;
+
+ if (phy_post_delay > 20)
+ msleep(phy_post_delay);
+ else
+ usleep_range(phy_post_delay * 1000,
+ phy_post_delay * 1000 + 1000);
+
+ return 0;
+}
+#else /* CONFIG_OF */
+int fec_reset_phy(struct platform_device *pdev)
+{
+ /* In case of platform probe, the reset has been done
+ * by machine code.
+ */
+ return 0;
+}
+#endif /* CONFIG_OF */
+
+void fec_enet_phy_reset_after_clk_enable(struct net_device *ndev)
+{
+ struct fec_enet_private *fep = netdev_priv(ndev);
+ struct phy_device *phy_dev = ndev->phydev;
+
+ if (phy_dev) {
+ phy_reset_after_clk_enable(phy_dev);
+ } else if (fep->phy_node) {
+ /* If the PHY still is not bound to the MAC, but there is
+ * OF PHY node and a matching PHY device instance already,
+ * use the OF PHY node to obtain the PHY device instance,
+ * and then use that PHY device instance when triggering
+ * the PHY reset.
+ */
+ phy_dev = of_phy_find_device(fep->phy_node);
+ phy_reset_after_clk_enable(phy_dev);
+ put_device(&phy_dev->mdio.dev);
+ }
+}
+
+int fec_enet_mdio_wait(struct fec_enet_private *fep)
+{
+ uint ievent;
+ int ret;
+
+ ret = readl_poll_timeout_atomic(fep->hwp + FEC_IEVENT, ievent,
+ ievent & FEC_ENET_MII, 2, 30000);
+
+ if (!ret)
+ writel(FEC_ENET_MII, fep->hwp + FEC_IEVENT);
+
+ return ret;
+}
+
+int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
+{
+ struct fec_enet_private *fep = bus->priv;
+ struct device *dev = &fep->pdev->dev;
+ int ret = 0, frame_start, frame_addr, frame_op;
+ bool is_c45 = !!(regnum & MII_ADDR_C45);
+
+ ret = pm_runtime_resume_and_get(dev);
+ if (ret < 0)
+ return ret;
+
+ if (is_c45) {
+ frame_start = FEC_MMFR_ST_C45;
+
+ /* write address */
+ frame_addr = (regnum >> 16);
+ writel(frame_start | FEC_MMFR_OP_ADDR_WRITE |
+ FEC_MMFR_PA(mii_id) | FEC_MMFR_RA(frame_addr) |
+ FEC_MMFR_TA | (regnum & 0xFFFF),
+ fep->hwp + FEC_MII_DATA);
+
+ /* wait for end of transfer */
+ ret = fec_enet_mdio_wait(fep);
+ if (ret) {
+ netdev_err(fep->netdev, "MDIO address write timeout\n");
+ goto out;
+ }
+
+ frame_op = FEC_MMFR_OP_READ_C45;
+
+ } else {
+ /* C22 read */
+ frame_op = FEC_MMFR_OP_READ;
+ frame_start = FEC_MMFR_ST;
+ frame_addr = regnum;
+ }
+
+ /* start a read op */
+ writel(frame_start | frame_op |
+ FEC_MMFR_PA(mii_id) | FEC_MMFR_RA(frame_addr) |
+ FEC_MMFR_TA, fep->hwp + FEC_MII_DATA);
+
+ /* wait for end of transfer */
+ ret = fec_enet_mdio_wait(fep);
+ if (ret) {
+ netdev_err(fep->netdev, "MDIO read timeout\n");
+ goto out;
+ }
+
+ ret = FEC_MMFR_DATA(readl(fep->hwp + FEC_MII_DATA));
+
+out:
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+
+ return ret;
+}
+
+int fec_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
+ u16 value)
+{
+ struct fec_enet_private *fep = bus->priv;
+ struct device *dev = &fep->pdev->dev;
+ int ret, frame_start, frame_addr;
+ bool is_c45 = !!(regnum & MII_ADDR_C45);
+
+ ret = pm_runtime_resume_and_get(dev);
+ if (ret < 0)
+ return ret;
+
+ if (is_c45) {
+ frame_start = FEC_MMFR_ST_C45;
+
+ /* write address */
+ frame_addr = (regnum >> 16);
+ writel(frame_start | FEC_MMFR_OP_ADDR_WRITE |
+ FEC_MMFR_PA(mii_id) | FEC_MMFR_RA(frame_addr) |
+ FEC_MMFR_TA | (regnum & 0xFFFF),
+ fep->hwp + FEC_MII_DATA);
+
+ /* wait for end of transfer */
+ ret = fec_enet_mdio_wait(fep);
+ if (ret) {
+ netdev_err(fep->netdev, "MDIO address write timeout\n");
+ goto out;
+ }
+ } else {
+ /* C22 write */
+ frame_start = FEC_MMFR_ST;
+ frame_addr = regnum;
+ }
+
+ /* start a write op */
+ writel(frame_start | FEC_MMFR_OP_WRITE |
+ FEC_MMFR_PA(mii_id) | FEC_MMFR_RA(frame_addr) |
+ FEC_MMFR_TA | FEC_MMFR_DATA(value),
+ fep->hwp + FEC_MII_DATA);
+
+ /* wait for end of transfer */
+ ret = fec_enet_mdio_wait(fep);
+ if (ret)
+ netdev_err(fep->netdev, "MDIO write timeout\n");
+
+out:
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+
+ return ret;
+}
+
+int fec_enet_mii_init(struct platform_device *pdev)
+{
+ static struct mii_bus *fec0_mii_bus;
+ struct net_device *ndev = platform_get_drvdata(pdev);
+ struct fec_enet_private *fep = netdev_priv(ndev);
+ bool suppress_preamble = false;
+ struct device_node *node;
+ int err = -ENXIO;
+ u32 mii_speed, holdtime;
+ u32 bus_freq;
+
+ /* The i.MX28 dual fec interfaces are not equal.
+ * Here are the differences:
+ *
+ * - fec0 supports MII & RMII modes while fec1 only supports RMII
+ * - fec0 acts as the 1588 time master while fec1 is slave
+ * - external phys can only be configured by fec0
+ *
+ * That is to say fec1 can not work independently. It only works
+ * when fec0 is working. The reason behind this design is that the
+ * second interface is added primarily for Switch mode.
+ *
+ * Because of the last point above, both phys are attached on fec0
+ * mdio interface in board design, and need to be configured by
+ * fec0 mii_bus.
+ */
+ if ((fep->quirks & FEC_QUIRK_SINGLE_MDIO) && fep->dev_id > 0) {
+ /* fec1 uses fec0 mii_bus */
+ if (mii_cnt && fec0_mii_bus) {
+ fep->mii_bus = fec0_mii_bus;
+ mii_cnt++;
+ return 0;
+ }
+ return -ENOENT;
+ }
+
+ bus_freq = 2500000; /* 2.5MHz by default */
+ node = of_get_child_by_name(pdev->dev.of_node, "mdio");
+ if (node) {
+ of_property_read_u32(node, "clock-frequency", &bus_freq);
+ suppress_preamble = of_property_read_bool(node,
+ "suppress-preamble");
+ }
+
+ /* Set MII speed (= clk_get_rate() / 2 * phy_speed)
+ *
+ * The formula for FEC MDC is 'ref_freq / (MII_SPEED x 2)' while
+ * for ENET-MAC is 'ref_freq / ((MII_SPEED + 1) x 2)'. The i.MX28
+ * Reference Manual has an error on this, and gets fixed on i.MX6Q
+ * document.
+ */
+ mii_speed = DIV_ROUND_UP(clk_get_rate(fep->clk_ipg), bus_freq * 2);
+ if (fep->quirks & FEC_QUIRK_ENET_MAC)
+ mii_speed--;
+ if (mii_speed > 63) {
+ dev_err(&pdev->dev,
+ "fec clock (%lu) too fast to get right mii speed\n",
+ clk_get_rate(fep->clk_ipg));
+ err = -EINVAL;
+ goto err_out;
+ }
+
+ /* The i.MX28 and i.MX6 types have another filed in the MSCR (aka
+ * MII_SPEED) register that defines the MDIO output hold time. Earlier
+ * versions are RAZ there, so just ignore the difference and write the
+ * register always.
+ * The minimal hold time according to IEE802.3 (clause 22) is 10 ns.
+ * HOLDTIME + 1 is the number of clk cycles the fec is holding the
+ * output.
+ * The HOLDTIME bitfield takes values between 0 and 7 (inclusive).
+ * Given that ceil(clkrate / 5000000) <= 64, the calculation for
+ * holdtime cannot result in a value greater than 3.
+ */
+ holdtime = DIV_ROUND_UP(clk_get_rate(fep->clk_ipg), 100000000) - 1;
+
+ fep->phy_speed = mii_speed << 1 | holdtime << 8;
+
+ if (suppress_preamble)
+ fep->phy_speed |= BIT(7);
+
+ if (fep->quirks & FEC_QUIRK_CLEAR_SETUP_MII) {
+ /* Clear MMFR to avoid to generate MII event by writing MSCR.
+ * MII event generation condition:
+ * - writing MSCR:
+ * - mmfr[31:0]_not_zero & mscr[7:0]_is_zero &
+ * mscr_reg_data_in[7:0] != 0
+ * - writing MMFR:
+ * - mscr[7:0]_not_zero
+ */
+ writel(0, fep->hwp + FEC_MII_DATA);
+ }
+
+ writel(fep->phy_speed, fep->hwp + FEC_MII_SPEED);
+
+ /* Clear any pending transaction complete indication */
+ writel(FEC_ENET_MII, fep->hwp + FEC_IEVENT);
+
+ fep->mii_bus = mdiobus_alloc();
+ if (!fep->mii_bus) {
+ err = -ENOMEM;
+ goto err_out;
+ }
+
+ fep->mii_bus->name = "fec_enet_mii_bus";
+ fep->mii_bus->read = fec_enet_mdio_read;
+ fep->mii_bus->write = fec_enet_mdio_write;
+ snprintf(fep->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",
+ pdev->name, fep->dev_id + 1);
+ fep->mii_bus->priv = fep;
+ fep->mii_bus->parent = &pdev->dev;
+
+ err = of_mdiobus_register(fep->mii_bus, node);
+ if (err)
+ goto err_out_free_mdiobus;
+ of_node_put(node);
+
+ mii_cnt++;
+
+ /* save fec0 mii_bus */
+ if (fep->quirks & FEC_QUIRK_SINGLE_MDIO)
+ fec0_mii_bus = fep->mii_bus;
+
+ return 0;
+
+err_out_free_mdiobus:
+ mdiobus_free(fep->mii_bus);
+err_out:
+ of_node_put(node);
+ return err;
+}
+
+void fec_enet_mii_remove(struct fec_enet_private *fep)
+{
+ if (--mii_cnt == 0) {
+ mdiobus_unregister(fep->mii_bus);
+ mdiobus_free(fep->mii_bus);
+ }
+}
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("NXP");
+MODULE_DESCRIPTION("i.MX FEC PHY");
diff --git a/drivers/net/ethernet/freescale/fec_phy.h b/drivers/net/ethernet/freescale/fec_phy.h
new file mode 100644
index 000000000000..085316e9425d
--- /dev/null
+++ b/drivers/net/ethernet/freescale/fec_phy.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+/* Copyright 1997 Dan Malek (dmalek@xxxxxxx)
+ * Copyright 2000 Ericsson Radio Systems AB.
+ * Copyright 2001-2005 Greg Ungerer (gerg@xxxxxxxxxxxx)
+ * Copyright 2004-2006 Macq Electronique SA.
+ * Copyright 2010-2011 Freescale Semiconductor, Inc.
+ * Copyright 2021 NXP
+ */
+
+/* FEC MII MMFR bits definition */
+#define FEC_MMFR_ST BIT(30)
+#define FEC_MMFR_ST_C45 (0)
+#define FEC_MMFR_OP_READ (2 << 28)
+#define FEC_MMFR_OP_READ_C45 (3 << 28)
+#define FEC_MMFR_OP_WRITE BIT(28)
+#define FEC_MMFR_OP_ADDR_WRITE (0)
+#define FEC_MMFR_PA(v) (((v) & 0x1f) << 23)
+#define FEC_MMFR_RA(v) (((v) & 0x1f) << 18)
+#define FEC_MMFR_TA (2 << 16)
+#define FEC_MMFR_DATA(v) ((v) & 0xffff)
+
+#define FEC_MDIO_PM_TIMEOUT 100 /* ms */
+
+int fec_reset_phy(struct platform_device *pdev);
+void fec_enet_phy_reset_after_clk_enable(struct net_device *ndev);
+int fec_enet_mdio_wait(struct fec_enet_private *fep);
+int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum);
+int fec_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum, u16 value);
+int fec_enet_mii_init(struct platform_device *pdev);
+void fec_enet_mii_remove(struct fec_enet_private *fep);
--
2.17.1