[PATCH v3 net-next 3/3] net: dsa: ocelot: felix: utilize shared mscc-miim driver for indirect MDIO access

From: Colin Foster
Date: Sun Nov 28 2021 - 21:00:29 EST

Switch to a shared MDIO access implementation by way of the mdio-mscc-miim
driver.

Signed-off-by: Colin Foster <colin.foster@xxxxxxxxxxxxxxxx>
Tested-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
---
drivers/net/dsa/ocelot/Kconfig | 1 +
drivers/net/dsa/ocelot/seville_vsc9953.c | 102 ++---------------------
drivers/net/mdio/mdio-mscc-miim.c | 38 ++++++---
include/linux/mdio/mdio-mscc-miim.h | 19 +++++
4 files changed, 56 insertions(+), 104 deletions(-)
create mode 100644 include/linux/mdio/mdio-mscc-miim.h

diff --git a/drivers/net/dsa/ocelot/Kconfig b/drivers/net/dsa/ocelot/Kconfig
index 9948544ba1c4..220b0b027b55 100644
--- a/drivers/net/dsa/ocelot/Kconfig
+++ b/drivers/net/dsa/ocelot/Kconfig
@@ -21,6 +21,7 @@ config NET_DSA_MSCC_SEVILLE
depends on NET_VENDOR_MICROSEMI
depends on HAS_IOMEM
depends on PTP_1588_CLOCK_OPTIONAL
+ select MDIO_MSCC_MIIM
select MSCC_OCELOT_SWITCH_LIB
select NET_DSA_TAG_OCELOT_8021Q
select NET_DSA_TAG_OCELOT
diff --git a/drivers/net/dsa/ocelot/seville_vsc9953.c b/drivers/net/dsa/ocelot/seville_vsc9953.c
index db124922c374..b9be889016ce 100644
--- a/drivers/net/dsa/ocelot/seville_vsc9953.c
+++ b/drivers/net/dsa/ocelot/seville_vsc9953.c
@@ -6,19 +6,14 @@
#include <soc/mscc/ocelot_vcap.h>
#include <soc/mscc/ocelot_sys.h>
#include <soc/mscc/ocelot.h>
+#include <linux/mdio/mdio-mscc-miim.h>
+#include <linux/of_mdio.h>
#include <linux/of_platform.h>
#include <linux/pcs-lynx.h>
#include <linux/dsa/ocelot.h>
#include <linux/iopoll.h>
-#include <linux/of_mdio.h>
#include "felix.h"

-#define MSCC_MIIM_CMD_OPR_WRITE BIT(1)
-#define MSCC_MIIM_CMD_OPR_READ BIT(2)
-#define MSCC_MIIM_CMD_WRDATA_SHIFT 4
-#define MSCC_MIIM_CMD_REGAD_SHIFT 20
-#define MSCC_MIIM_CMD_PHYAD_SHIFT 25
-#define MSCC_MIIM_CMD_VLD BIT(31)
#define VSC9953_VCAP_POLICER_BASE 11
#define VSC9953_VCAP_POLICER_MAX 31
#define VSC9953_VCAP_POLICER_BASE2 120
@@ -862,7 +857,6 @@ static struct vcap_props vsc9953_vcap_props[] = {
#define VSC9953_INIT_TIMEOUT 50000
#define VSC9953_GCB_RST_SLEEP 100
#define VSC9953_SYS_RAMINIT_SLEEP 80
-#define VCS9953_MII_TIMEOUT 10000

static int vsc9953_gcb_soft_rst_status(struct ocelot *ocelot)
{
@@ -882,82 +876,6 @@ static int vsc9953_sys_ram_init_status(struct ocelot *ocelot)
return val;
}

-static int vsc9953_gcb_miim_pending_status(struct ocelot *ocelot)
-{
- int val;
-
- ocelot_field_read(ocelot, GCB_MIIM_MII_STATUS_PENDING, &val);
-
- return val;
-}
-
-static int vsc9953_gcb_miim_busy_status(struct ocelot *ocelot)
-{
- int val;
-
- ocelot_field_read(ocelot, GCB_MIIM_MII_STATUS_BUSY, &val);
-
- return val;
-}
-
-static int vsc9953_mdio_write(struct mii_bus *bus, int phy_id, int regnum,
- u16 value)
-{
- struct ocelot *ocelot = bus->priv;
- int err, cmd, val;
-
- /* Wait while MIIM controller becomes idle */
- err = readx_poll_timeout(vsc9953_gcb_miim_pending_status, ocelot,
- val, !val, 10, VCS9953_MII_TIMEOUT);
- if (err) {
- dev_err(ocelot->dev, "MDIO write: pending timeout\n");
- goto out;
- }
-
- cmd = MSCC_MIIM_CMD_VLD | (phy_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
- (regnum << MSCC_MIIM_CMD_REGAD_SHIFT) |
- (value << MSCC_MIIM_CMD_WRDATA_SHIFT) |
- MSCC_MIIM_CMD_OPR_WRITE;
-
- ocelot_write(ocelot, cmd, GCB_MIIM_MII_CMD);
-
-out:
- return err;
-}
-
-static int vsc9953_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
-{
- struct ocelot *ocelot = bus->priv;
- int err, cmd, val;
-
- /* Wait until MIIM controller becomes idle */
- err = readx_poll_timeout(vsc9953_gcb_miim_pending_status, ocelot,
- val, !val, 10, VCS9953_MII_TIMEOUT);
- if (err) {
- dev_err(ocelot->dev, "MDIO read: pending timeout\n");
- goto out;
- }
-
- /* Write the MIIM COMMAND register */
- cmd = MSCC_MIIM_CMD_VLD | (phy_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
- (regnum << MSCC_MIIM_CMD_REGAD_SHIFT) | MSCC_MIIM_CMD_OPR_READ;
-
- ocelot_write(ocelot, cmd, GCB_MIIM_MII_CMD);
-
- /* Wait while read operation via the MIIM controller is in progress */
- err = readx_poll_timeout(vsc9953_gcb_miim_busy_status, ocelot,
- val, !val, 10, VCS9953_MII_TIMEOUT);
- if (err) {
- dev_err(ocelot->dev, "MDIO read: busy timeout\n");
- goto out;
- }
-
- val = ocelot_read(ocelot, GCB_MIIM_MII_DATA);
-
- err = val & 0xFFFF;
-out:
- return err;
-}

/* CORE_ENA is in SYS:SYSTEM:RESET_CFG
* MEM_INIT is in SYS:SYSTEM:RESET_CFG
@@ -1101,16 +1019,14 @@ static int vsc9953_mdio_bus_alloc(struct ocelot *ocelot)
return -ENOMEM;
}

- bus = devm_mdiobus_alloc(dev);
- if (!bus)
- return -ENOMEM;
+ rc = mscc_miim_setup(dev, &bus, "VSC9953 internal MDIO bus",
+ ocelot->targets[GCB],
+ ocelot->map[GCB][GCB_MIIM_MII_STATUS & REG_MASK]);

- bus->name = "VSC9953 internal MDIO bus";
- bus->read = vsc9953_mdio_read;
- bus->write = vsc9953_mdio_write;
- bus->parent = dev;
- bus->priv = ocelot;
- snprintf(bus->id, MII_BUS_ID_SIZE, "%s-imdio", dev_name(dev));
+ if (rc) {
+ dev_err(dev, "failed to setup MDIO bus\n");
+ return rc;
+ }

/* Needed in order to initialize the bus mutex lock */
rc = of_mdiobus_register(bus, NULL);
diff --git a/drivers/net/mdio/mdio-mscc-miim.c b/drivers/net/mdio/mdio-mscc-miim.c
index e016b32ad208..2d420c9d7520 100644
--- a/drivers/net/mdio/mdio-mscc-miim.c
+++ b/drivers/net/mdio/mdio-mscc-miim.c
@@ -10,6 +10,7 @@
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
+#include <linux/mdio/mdio-mscc-miim.h>
#include <linux/module.h>
#include <linux/of_mdio.h>
#include <linux/phy.h>
@@ -37,7 +38,9 @@

struct mscc_miim_dev {
struct regmap *regs;
+ int mii_status_offset;
struct regmap *phy_regs;
+ int phy_reset_offset;
};

/* When high resolution timers aren't built-in: we can't use usleep_range() as
@@ -56,7 +59,8 @@ static int mscc_miim_status(struct mii_bus *bus)
struct mscc_miim_dev *miim = bus->priv;
int val, ret;

- ret = regmap_read(miim->regs, MSCC_MIIM_REG_STATUS, &val);
+ ret = regmap_read(miim->regs,
+ MSCC_MIIM_REG_STATUS + miim->mii_status_offset, &val);
if (ret < 0) {
WARN_ONCE(1, "mscc miim status read error %d\n", ret);
return ret;
@@ -93,7 +97,9 @@ static int mscc_miim_read(struct mii_bus *bus, int mii_id, int regnum)
if (ret)
goto out;

- ret = regmap_write(miim->regs, MSCC_MIIM_REG_CMD, MSCC_MIIM_CMD_VLD |
+ ret = regmap_write(miim->regs,
+ MSCC_MIIM_REG_CMD + miim->mii_status_offset,
+ MSCC_MIIM_CMD_VLD |
(mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
(regnum << MSCC_MIIM_CMD_REGAD_SHIFT) |
MSCC_MIIM_CMD_OPR_READ);
@@ -107,8 +113,8 @@ static int mscc_miim_read(struct mii_bus *bus, int mii_id, int regnum)
if (ret)
goto out;

- ret = regmap_read(miim->regs, MSCC_MIIM_REG_DATA, &val);
-
+ ret = regmap_read(miim->regs,
+ MSCC_MIIM_REG_DATA + miim->mii_status_offset, &val);
if (ret < 0) {
WARN_ONCE(1, "mscc miim read data reg error %d\n", ret);
goto out;
@@ -134,7 +140,9 @@ static int mscc_miim_write(struct mii_bus *bus, int mii_id,
if (ret < 0)
goto out;

- ret = regmap_write(miim->regs, MSCC_MIIM_REG_CMD, MSCC_MIIM_CMD_VLD |
+ ret = regmap_write(miim->regs,
+ MSCC_MIIM_REG_CMD + miim->mii_status_offset,
+ MSCC_MIIM_CMD_VLD |
(mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
(regnum << MSCC_MIIM_CMD_REGAD_SHIFT) |
(value << MSCC_MIIM_CMD_WRDATA_SHIFT) |
@@ -149,16 +157,19 @@ static int mscc_miim_write(struct mii_bus *bus, int mii_id,
static int mscc_miim_reset(struct mii_bus *bus)
{
struct mscc_miim_dev *miim = bus->priv;
+ int offset = miim->phy_reset_offset;
int ret;

if (miim->phy_regs) {
- ret = regmap_write(miim->phy_regs, MSCC_PHY_REG_PHY_CFG, 0);
+ ret = regmap_write(miim->phy_regs,
+ MSCC_PHY_REG_PHY_CFG + offset, 0);
if (ret < 0) {
WARN_ONCE(1, "mscc reset set error %d\n", ret);
return ret;
}

- ret = regmap_write(miim->phy_regs, MSCC_PHY_REG_PHY_CFG, 0x1ff);
+ ret = regmap_write(miim->phy_regs,
+ MSCC_PHY_REG_PHY_CFG + offset, 0x1ff);
if (ret < 0) {
WARN_ONCE(1, "mscc reset clear error %d\n", ret);
return ret;
@@ -176,8 +187,8 @@ static const struct regmap_config mscc_miim_regmap_config = {
.reg_stride = 4,
};

-static int mscc_miim_setup(struct device *dev, struct mii_bus **pbus,
- struct regmap *mii_regmap)
+int mscc_miim_setup(struct device *dev, struct mii_bus **pbus, const char *name,
+ struct regmap *mii_regmap, int status_offset)
{
struct mscc_miim_dev *miim;
struct mii_bus *bus;
@@ -186,7 +197,7 @@ static int mscc_miim_setup(struct device *dev, struct mii_bus **pbus,
if (!bus)
return -ENOMEM;

- bus->name = "mscc_miim";
+ bus->name = name;
bus->read = mscc_miim_read;
bus->write = mscc_miim_write;
bus->reset = mscc_miim_reset;
@@ -198,9 +209,13 @@ static int mscc_miim_setup(struct device *dev, struct mii_bus **pbus,
*pbus = bus;

miim->regs = mii_regmap;
+ miim->mii_status_offset = status_offset;
+
+ *pbus = bus;

return 0;
}
+EXPORT_SYMBOL(mscc_miim_setup);

static int mscc_miim_probe(struct platform_device *pdev)
{
@@ -237,7 +252,7 @@ static int mscc_miim_probe(struct platform_device *pdev)
return PTR_ERR(phy_regmap);
}

- ret = mscc_miim_setup(&pdev->dev, &bus, mii_regmap);
+ ret = mscc_miim_setup(&pdev->dev, &bus, "mscc_miim", mii_regmap, 0);
if (ret < 0) {
dev_err(&pdev->dev, "Unable to setup the MDIO bus\n");
return ret;
@@ -245,6 +260,7 @@ static int mscc_miim_probe(struct platform_device *pdev)

miim = bus->priv;
miim->phy_regs = phy_regmap;
+ miim->phy_reset_offset = 0;

ret = of_mdiobus_register(bus, pdev->dev.of_node);
if (ret < 0) {
diff --git a/include/linux/mdio/mdio-mscc-miim.h b/include/linux/mdio/mdio-mscc-miim.h
new file mode 100644
index 000000000000..5b4ed2c3cbb9
--- /dev/null
+++ b/include/linux/mdio/mdio-mscc-miim.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */
+/*
+ * Driver for the MDIO interface of Microsemi network switches.
+ *
+ * Author: Colin Foster <colin.foster@xxxxxxxxxxxxxxxx>
+ * Copyright (C) 2021 Innovative Advantage
+ */
+#ifndef MDIO_MSCC_MIIM_H
+#define MDIO_MSCC_MIIM_H
+
+#include <linux/device.h>
+#include <linux/phy.h>
+#include <linux/regmap.h>
+
+int mscc_miim_setup(struct device *device, struct mii_bus **bus,
+ const char *name, struct regmap *mii_regmap,
+ int status_offset);
+
+#endif
--
2.25.1