Merge branch 'sfp-infra'

Russell King says:

====================
Initial SFP support patches

Please review and merge this initial patch set, which is part of a
larger set previously posted adding SFP support to phy and mvneta.

This initial set are focused on cleaning up and reorganising the
fixed-phy code to allow the core software-phy code to be re-used.

These are based on net-next.
====================

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

5 files changed, 222 insertions, 126 deletions

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 8dac88abbc39..f96829415ce6 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -12,6 +12,9 @@ menuconfig PHYLIB
 
 if PHYLIB
 
+config SWPHY
+	bool
+
 comment "MII PHY device drivers"
 
 config AQUANTIA_PHY
@@ -159,6 +162,7 @@ config MICROCHIP_PHY
 config FIXED_PHY
 	tristate "Driver for MDIO Bus/PHY emulation with fixed speed/link PHYs"
 	depends on PHYLIB
+	select SWPHY
 	---help---
 	  Adds the platform "fixed" MDIO Bus to cover the boards that use
 	  PHYs that are not connected to the real MDIO bus.
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 4170642a2035..7158274327d0 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -1,6 +1,7 @@
 # Makefile for Linux PHY drivers
 
-libphy-objs			:= phy.o phy_device.o mdio_bus.o mdio_device.o
+libphy-y			:= phy.o phy_device.o mdio_bus.o mdio_device.o
+libphy-$(CONFIG_SWPHY)		+= swphy.o
 
 obj-$(CONFIG_PHYLIB)		+= libphy.o
 obj-$(CONFIG_AQUANTIA_PHY)	+= aquantia.o
diff --git a/drivers/net/phy/fixed_phy.c b/drivers/net/phy/fixed_phy.c
index 2d2e4339f0df..b376ada83598 100644
--- a/drivers/net/phy/fixed_phy.c
+++ b/drivers/net/phy/fixed_phy.c
@@ -23,8 +23,9 @@
 #include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/gpio.h>
+#include <linux/seqlock.h>
 
-#define MII_REGS_NUM 29
+#include "swphy.h"
 
 struct fixed_mdio_bus {
 	struct mii_bus *mii_bus;
@@ -33,8 +34,8 @@ struct fixed_mdio_bus {
 
 struct fixed_phy {
 	int addr;
-	u16 regs[MII_REGS_NUM];
 	struct phy_device *phydev;
+	seqcount_t seqcount;
 	struct fixed_phy_status status;
 	int (*link_update)(struct net_device *, struct fixed_phy_status *);
 	struct list_head node;
@@ -46,103 +47,10 @@ static struct fixed_mdio_bus platform_fmb = {
 	.phys = LIST_HEAD_INIT(platform_fmb.phys),
 };
 
-static int fixed_phy_update_regs(struct fixed_phy *fp)
+static void fixed_phy_update(struct fixed_phy *fp)
 {
-	u16 bmsr = BMSR_ANEGCAPABLE;
-	u16 bmcr = 0;
-	u16 lpagb = 0;
-	u16 lpa = 0;
-
 	if (gpio_is_valid(fp->link_gpio))
 		fp->status.link = !!gpio_get_value_cansleep(fp->link_gpio);
-
-	if (fp->status.duplex) {
-		switch (fp->status.speed) {
-		case 1000:
-			bmsr |= BMSR_ESTATEN;
-			break;
-		case 100:
-			bmsr |= BMSR_100FULL;
-			break;
-		case 10:
-			bmsr |= BMSR_10FULL;
-			break;
-		default:
-			break;
-		}
-	} else {
-		switch (fp->status.speed) {
-		case 1000:
-			bmsr |= BMSR_ESTATEN;
-			break;
-		case 100:
-			bmsr |= BMSR_100HALF;
-			break;
-		case 10:
-			bmsr |= BMSR_10HALF;
-			break;
-		default:
-			break;
-		}
-	}
-
-	if (fp->status.link) {
-		bmsr |= BMSR_LSTATUS | BMSR_ANEGCOMPLETE;
-
-		if (fp->status.duplex) {
-			bmcr |= BMCR_FULLDPLX;
-
-			switch (fp->status.speed) {
-			case 1000:
-				bmcr |= BMCR_SPEED1000;
-				lpagb |= LPA_1000FULL;
-				break;
-			case 100:
-				bmcr |= BMCR_SPEED100;
-				lpa |= LPA_100FULL;
-				break;
-			case 10:
-				lpa |= LPA_10FULL;
-				break;
-			default:
-				pr_warn("fixed phy: unknown speed\n");
-				return -EINVAL;
-			}
-		} else {
-			switch (fp->status.speed) {
-			case 1000:
-				bmcr |= BMCR_SPEED1000;
-				lpagb |= LPA_1000HALF;
-				break;
-			case 100:
-				bmcr |= BMCR_SPEED100;
-				lpa |= LPA_100HALF;
-				break;
-			case 10:
-				lpa |= LPA_10HALF;
-				break;
-			default:
-				pr_warn("fixed phy: unknown speed\n");
-			return -EINVAL;
-			}
-		}
-
-		if (fp->status.pause)
-			lpa |= LPA_PAUSE_CAP;
-
-		if (fp->status.asym_pause)
-			lpa |= LPA_PAUSE_ASYM;
-	}
-
-	fp->regs[MII_PHYSID1] = 0;
-	fp->regs[MII_PHYSID2] = 0;
-
-	fp->regs[MII_BMSR] = bmsr;
-	fp->regs[MII_BMCR] = bmcr;
-	fp->regs[MII_LPA] = lpa;
-	fp->regs[MII_STAT1000] = lpagb;
-
-	return 0;
 }
 
 static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
@@ -150,29 +58,23 @@ static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
 	struct fixed_mdio_bus *fmb = bus->priv;
 	struct fixed_phy *fp;
 
-	if (reg_num >= MII_REGS_NUM)
-		return -1;
-
-	/* We do not support emulating Clause 45 over Clause 22 register reads
-	 * return an error instead of bogus data.
-	 */
-	switch (reg_num) {
-	case MII_MMD_CTRL:
-	case MII_MMD_DATA:
-		return -1;
-	default:
-		break;
-	}
-
 	list_for_each_entry(fp, &fmb->phys, node) {
 		if (fp->addr == phy_addr) {
-			/* Issue callback if user registered it. */
-			if (fp->link_update) {
-				fp->link_update(fp->phydev->attached_dev,
-						&fp->status);
-				fixed_phy_update_regs(fp);
-			}
-			return fp->regs[reg_num];
+			struct fixed_phy_status state;
+			int s;
+
+			do {
+				s = read_seqcount_begin(&fp->seqcount);
+				/* Issue callback if user registered it. */
+				if (fp->link_update) {
+					fp->link_update(fp->phydev->attached_dev,
+							&fp->status);
+					fixed_phy_update(fp);
+				}
+				state = fp->status;
+			} while (read_seqcount_retry(&fp->seqcount, s));
+
+			return swphy_read_reg(reg_num, &state);
 		}
 	}
 
@@ -224,6 +126,7 @@ int fixed_phy_update_state(struct phy_device *phydev,
 
 	list_for_each_entry(fp, &fmb->phys, node) {
 		if (fp->addr == phydev->mdio.addr) {
+			write_seqcount_begin(&fp->seqcount);
 #define _UPD(x) if (changed->x) \
 	fp->status.x = status->x
 			_UPD(link);
@@ -232,7 +135,8 @@ int fixed_phy_update_state(struct phy_device *phydev,
 			_UPD(pause);
 			_UPD(asym_pause);
 #undef _UPD
-			fixed_phy_update_regs(fp);
+			fixed_phy_update(fp);
+			write_seqcount_end(&fp->seqcount);
 			return 0;
 		}
 	}
@@ -249,11 +153,15 @@ int fixed_phy_add(unsigned int irq, int phy_addr,
 	struct fixed_mdio_bus *fmb = &platform_fmb;
 	struct fixed_phy *fp;
 
+	ret = swphy_validate_state(status);
+	if (ret < 0)
+		return ret;
+
 	fp = kzalloc(sizeof(*fp), GFP_KERNEL);
 	if (!fp)
 		return -ENOMEM;
 
-	memset(fp->regs, 0xFF,  sizeof(fp->regs[0]) * MII_REGS_NUM);
+	seqcount_init(&fp->seqcount);
 
 	if (irq != PHY_POLL)
 		fmb->mii_bus->irq[phy_addr] = irq;
@@ -269,17 +177,12 @@ int fixed_phy_add(unsigned int irq, int phy_addr,
 			goto err_regs;
 	}
 
-	ret = fixed_phy_update_regs(fp);
-	if (ret)
-		goto err_gpio;
+	fixed_phy_update(fp);
 
 	list_add_tail(&fp->node, &fmb->phys);
 
 	return 0;
 
-err_gpio:
-	if (gpio_is_valid(fp->link_gpio))
-		gpio_free(fp->link_gpio);
 err_regs:
 	kfree(fp);
 	return ret;
diff --git a/drivers/net/phy/swphy.c b/drivers/net/phy/swphy.c
new file mode 100644
index 000000000000..34f58f2349e9
--- /dev/null
+++ b/drivers/net/phy/swphy.c
@@ -0,0 +1,179 @@
+/*
+ * Software PHY emulation
+ *
+ * Code taken from fixed_phy.c by Russell King <rmk+kernel@arm.linux.org.uk>
+ *
+ * Author: Vitaly Bordug <vbordug@ru.mvista.com>
+ *         Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * Copyright (c) 2006-2007 MontaVista Software, Inc.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+#include <linux/export.h>
+#include <linux/mii.h>
+#include <linux/phy.h>
+#include <linux/phy_fixed.h>
+
+#include "swphy.h"
+
+#define MII_REGS_NUM 29
+
+struct swmii_regs {
+	u16 bmcr;
+	u16 bmsr;
+	u16 lpa;
+	u16 lpagb;
+};
+
+enum {
+	SWMII_SPEED_10 = 0,
+	SWMII_SPEED_100,
+	SWMII_SPEED_1000,
+	SWMII_DUPLEX_HALF = 0,
+	SWMII_DUPLEX_FULL,
+};
+
+/*
+ * These two tables get bitwise-anded together to produce the final result.
+ * This means the speed table must contain both duplex settings, and the
+ * duplex table must contain all speed settings.
+ */
+static const struct swmii_regs speed[] = {
+	[SWMII_SPEED_10] = {
+		.bmcr  = BMCR_FULLDPLX,
+		.lpa   = LPA_10FULL | LPA_10HALF,
+	},
+	[SWMII_SPEED_100] = {
+		.bmcr  = BMCR_FULLDPLX | BMCR_SPEED100,
+		.bmsr  = BMSR_100FULL | BMSR_100HALF,
+		.lpa   = LPA_100FULL | LPA_100HALF,
+	},
+	[SWMII_SPEED_1000] = {
+		.bmcr  = BMCR_FULLDPLX | BMCR_SPEED1000,
+		.bmsr  = BMSR_ESTATEN,
+		.lpagb = LPA_1000FULL | LPA_1000HALF,
+	},
+};
+
+static const struct swmii_regs duplex[] = {
+	[SWMII_DUPLEX_HALF] = {
+		.bmcr  = ~BMCR_FULLDPLX,
+		.bmsr  = BMSR_ESTATEN | BMSR_100HALF,
+		.lpa   = LPA_10HALF | LPA_100HALF,
+		.lpagb = LPA_1000HALF,
+	},
+	[SWMII_DUPLEX_FULL] = {
+		.bmcr  = ~0,
+		.bmsr  = BMSR_ESTATEN | BMSR_100FULL,
+		.lpa   = LPA_10FULL | LPA_100FULL,
+		.lpagb = LPA_1000FULL,
+	},
+};
+
+static int swphy_decode_speed(int speed)
+{
+	switch (speed) {
+	case 1000:
+		return SWMII_SPEED_1000;
+	case 100:
+		return SWMII_SPEED_100;
+	case 10:
+		return SWMII_SPEED_10;
+	default:
+		return -EINVAL;
+	}
+}
+
+/**
+ * swphy_validate_state - validate the software phy status
+ * @state: software phy status
+ *
+ * This checks that we can represent the state stored in @state can be
+ * represented in the emulated MII registers.  Returns 0 if it can,
+ * otherwise returns -EINVAL.
+ */
+int swphy_validate_state(const struct fixed_phy_status *state)
+{
+	int err;
+
+	if (state->link) {
+		err = swphy_decode_speed(state->speed);
+		if (err < 0) {
+			pr_warn("swphy: unknown speed\n");
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(swphy_validate_state);
+
+/**
+ * swphy_read_reg - return a MII register from the fixed phy state
+ * @reg: MII register
+ * @state: fixed phy status
+ *
+ * Return the MII @reg register generated from the fixed phy state @state.
+ */
+int swphy_read_reg(int reg, const struct fixed_phy_status *state)
+{
+	int speed_index, duplex_index;
+	u16 bmsr = BMSR_ANEGCAPABLE;
+	u16 bmcr = 0;
+	u16 lpagb = 0;
+	u16 lpa = 0;
+
+	if (reg > MII_REGS_NUM)
+		return -1;
+
+	speed_index = swphy_decode_speed(state->speed);
+	if (WARN_ON(speed_index < 0))
+		return 0;
+
+	duplex_index = state->duplex ? SWMII_DUPLEX_FULL : SWMII_DUPLEX_HALF;
+
+	bmsr |= speed[speed_index].bmsr & duplex[duplex_index].bmsr;
+
+	if (state->link) {
+		bmsr |= BMSR_LSTATUS | BMSR_ANEGCOMPLETE;
+
+		bmcr  |= speed[speed_index].bmcr  & duplex[duplex_index].bmcr;
+		lpa   |= speed[speed_index].lpa   & duplex[duplex_index].lpa;
+		lpagb |= speed[speed_index].lpagb & duplex[duplex_index].lpagb;
+
+		if (state->pause)
+			lpa |= LPA_PAUSE_CAP;
+
+		if (state->asym_pause)
+			lpa |= LPA_PAUSE_ASYM;
+	}
+
+	switch (reg) {
+	case MII_BMCR:
+		return bmcr;
+	case MII_BMSR:
+		return bmsr;
+	case MII_PHYSID1:
+	case MII_PHYSID2:
+		return 0;
+	case MII_LPA:
+		return lpa;
+	case MII_STAT1000:
+		return lpagb;
+
+	/*
+	 * We do not support emulating Clause 45 over Clause 22 register
+	 * reads.  Return an error instead of bogus data.
+	 */
+	case MII_MMD_CTRL:
+	case MII_MMD_DATA:
+		return -1;
+
+	default:
+		return 0xffff;
+	}
+}
+EXPORT_SYMBOL_GPL(swphy_read_reg);
diff --git a/drivers/net/phy/swphy.h b/drivers/net/phy/swphy.h
new file mode 100644
index 000000000000..2f09ac324e18
--- /dev/null
+++ b/drivers/net/phy/swphy.h
@@ -0,0 +1,9 @@
+#ifndef SWPHY_H
+#define SWPHY_H
+
+struct fixed_phy_status;
+
+int swphy_validate_state(const struct fixed_phy_status *state);
+int swphy_read_reg(int reg, const struct fixed_phy_status *state);
+
+#endif