Merge branch 'seville-shared-mdio'

Colin Foster says:

====================
update seville to use shared MDIO driver

This patch set exposes and utilizes the shared MDIO bus in
drivers/net/mdio/msio-mscc-miim.c

v3:
    * Fix errors using uninitilized "dev" inside the probe function.
    * Remove phy_regmap from the setup function, since it currently
    isn't used
    * Remove GCB_PHY_PHY_CFG definition from ocelot.h - it isn't used
    yet...

v2:
    * Error handling (thanks Andrew Lunn)
    * Fix logic errors calling mscc_miim_setup during patch 1/3 (thanks
    Jakub Kicinski)
    * Remove unnecessary felix_mdio file (thanks Vladimir Oltean)
    * Pass NULL to mscc_miim_setup instead of GCB_PHY_PHY_CFG, since the
    phy reset isn't handled at that point of the Seville driver (patch
    3/3)
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 168 insertions, 136 deletions

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 899b98193b4a..b9be889016ce 100644
--- a/drivers/net/dsa/ocelot/seville_vsc9953.c
+++ b/drivers/net/dsa/ocelot/seville_vsc9953.c
@@ -6,18 +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 "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
@@ -861,7 +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)
 {
@@ -881,82 +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
@@ -1100,19 +1019,17 @@ 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 = mdiobus_register(bus);
+	rc = of_mdiobus_register(bus, NULL);
 	if (rc < 0) {
 		dev_err(dev, "failed to register MDIO bus\n");
 		return rc;
diff --git a/drivers/net/mdio/mdio-mscc-miim.c b/drivers/net/mdio/mdio-mscc-miim.c
index 17f98f609ec8..2d420c9d7520 100644
--- a/drivers/net/mdio/mdio-mscc-miim.c
+++ b/drivers/net/mdio/mdio-mscc-miim.c
@@ -10,10 +10,12 @@
 #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>
 #include <linux/platform_device.h>
+#include <linux/regmap.h>
 
 #define MSCC_MIIM_REG_STATUS		0x0
 #define		MSCC_MIIM_STATUS_STAT_PENDING	BIT(2)
@@ -35,37 +37,52 @@
 #define MSCC_PHY_REG_PHY_STATUS	0x4
 
 struct mscc_miim_dev {
-	void __iomem *regs;
-	void __iomem *phy_regs;
+	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
  * we would sleep way too long. Use udelay() instead.
  */
-#define mscc_readl_poll_timeout(addr, val, cond, delay_us, timeout_us)	\
-({									\
-	if (!IS_ENABLED(CONFIG_HIGH_RES_TIMERS))			\
-		readl_poll_timeout_atomic(addr, val, cond, delay_us,	\
-					  timeout_us);			\
-	readl_poll_timeout(addr, val, cond, delay_us, timeout_us);	\
+#define mscc_readx_poll_timeout(op, addr, val, cond, delay_us, timeout_us)\
+({									  \
+	if (!IS_ENABLED(CONFIG_HIGH_RES_TIMERS))			  \
+		readx_poll_timeout_atomic(op, addr, val, cond, delay_us,  \
+					  timeout_us);			  \
+	readx_poll_timeout(op, addr, val, cond, delay_us, timeout_us);	  \
 })
 
-static int mscc_miim_wait_ready(struct mii_bus *bus)
+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 + miim->mii_status_offset, &val);
+	if (ret < 0) {
+		WARN_ONCE(1, "mscc miim status read error %d\n", ret);
+		return ret;
+	}
+
+	return val;
+}
+
+static int mscc_miim_wait_ready(struct mii_bus *bus)
+{
 	u32 val;
 
-	return mscc_readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val,
+	return mscc_readx_poll_timeout(mscc_miim_status, bus, val,
 				       !(val & MSCC_MIIM_STATUS_STAT_BUSY), 50,
 				       10000);
 }
 
 static int mscc_miim_wait_pending(struct mii_bus *bus)
 {
-	struct mscc_miim_dev *miim = bus->priv;
 	u32 val;
 
-	return mscc_readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val,
+	return mscc_readx_poll_timeout(mscc_miim_status, bus, val,
 				       !(val & MSCC_MIIM_STATUS_STAT_PENDING),
 				       50, 10000);
 }
@@ -80,15 +97,29 @@ static int mscc_miim_read(struct mii_bus *bus, int mii_id, int regnum)
 	if (ret)
 		goto out;
 
-	writel(MSCC_MIIM_CMD_VLD | (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
-	       (regnum << MSCC_MIIM_CMD_REGAD_SHIFT) | MSCC_MIIM_CMD_OPR_READ,
-	       miim->regs + MSCC_MIIM_REG_CMD);
+	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);
+
+	if (ret < 0) {
+		WARN_ONCE(1, "mscc miim write cmd reg error %d\n", ret);
+		goto out;
+	}
 
 	ret = mscc_miim_wait_ready(bus);
 	if (ret)
 		goto out;
 
-	val = readl(miim->regs + MSCC_MIIM_REG_DATA);
+	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;
+	}
+
 	if (val & MSCC_MIIM_DATA_ERROR) {
 		ret = -EIO;
 		goto out;
@@ -109,12 +140,16 @@ static int mscc_miim_write(struct mii_bus *bus, int mii_id,
 	if (ret < 0)
 		goto out;
 
-	writel(MSCC_MIIM_CMD_VLD | (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
-	       (regnum << MSCC_MIIM_CMD_REGAD_SHIFT) |
-	       (value << MSCC_MIIM_CMD_WRDATA_SHIFT) |
-	       MSCC_MIIM_CMD_OPR_WRITE,
-	       miim->regs + MSCC_MIIM_REG_CMD);
+	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) |
+			   MSCC_MIIM_CMD_OPR_WRITE);
 
+	if (ret < 0)
+		WARN_ONCE(1, "mscc miim write error %d\n", ret);
 out:
 	return ret;
 }
@@ -122,51 +157,111 @@ out:
 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) {
-		writel(0, miim->phy_regs + MSCC_PHY_REG_PHY_CFG);
-		writel(0x1ff, miim->phy_regs + MSCC_PHY_REG_PHY_CFG);
+		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 + offset, 0x1ff);
+		if (ret < 0) {
+			WARN_ONCE(1, "mscc reset clear error %d\n", ret);
+			return ret;
+		}
+
 		mdelay(500);
 	}
 
 	return 0;
 }
 
-static int mscc_miim_probe(struct platform_device *pdev)
+static const struct regmap_config mscc_miim_regmap_config = {
+	.reg_bits	= 32,
+	.val_bits	= 32,
+	.reg_stride	= 4,
+};
+
+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 *dev;
-	struct resource *res;
+	struct mscc_miim_dev *miim;
 	struct mii_bus *bus;
-	int ret;
 
-	bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*dev));
+	bus = devm_mdiobus_alloc_size(dev, sizeof(*miim));
 	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;
-	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
-	bus->parent = &pdev->dev;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(dev));
+	bus->parent = dev;
+
+	miim = bus->priv;
+
+	*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)
+{
+	struct regmap *mii_regmap, *phy_regmap;
+	void __iomem *regs, *phy_regs;
+	struct mscc_miim_dev *miim;
+	struct mii_bus *bus;
+	int ret;
 
-	dev = bus->priv;
-	dev->regs = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
-	if (IS_ERR(dev->regs)) {
+	regs = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
+	if (IS_ERR(regs)) {
 		dev_err(&pdev->dev, "Unable to map MIIM registers\n");
-		return PTR_ERR(dev->regs);
+		return PTR_ERR(regs);
 	}
 
-	/* This resource is optional */
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-	if (res) {
-		dev->phy_regs = devm_ioremap_resource(&pdev->dev, res);
-		if (IS_ERR(dev->phy_regs)) {
-			dev_err(&pdev->dev, "Unable to map internal phy registers\n");
-			return PTR_ERR(dev->phy_regs);
-		}
+	mii_regmap = devm_regmap_init_mmio(&pdev->dev, regs,
+					   &mscc_miim_regmap_config);
+
+	if (IS_ERR(mii_regmap)) {
+		dev_err(&pdev->dev, "Unable to create MIIM regmap\n");
+		return PTR_ERR(mii_regmap);
 	}
 
+	phy_regs = devm_platform_ioremap_resource(pdev, 1);
+	if (IS_ERR(phy_regs)) {
+		dev_err(&pdev->dev, "Unable to map internal phy registers\n");
+		return PTR_ERR(phy_regs);
+	}
+
+	phy_regmap = devm_regmap_init_mmio(&pdev->dev, phy_regs,
+					   &mscc_miim_regmap_config);
+	if (IS_ERR(phy_regmap)) {
+		dev_err(&pdev->dev, "Unable to create phy register regmap\n");
+		return PTR_ERR(phy_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;
+	}
+
+	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) {
 		dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
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@in-advantage.com>
+ * 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