phy: generate swphy registers on the fly

Generate software phy registers as and when requested, rather than
duplicating the state in fixed_phy.  This allows us to eliminate
the duplicate storage of of the same data, which is only different
in format.

As fixed_phy_update_regs() no longer updates register state, rename
it to fixed_phy_update().

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/fixed_phy.c

@@ -26,8 +26,6 @@
 
 #include "swphy.h"
 
-#define MII_REGS_NUM 29
-
 struct fixed_mdio_bus {
 	struct mii_bus *mii_bus;
 	struct list_head phys;
@@ -35,7 +33,6 @@ struct fixed_mdio_bus {
 
 struct fixed_phy {
 	int addr;
-	u16 regs[MII_REGS_NUM];
 	struct phy_device *phydev;
 	struct fixed_phy_status status;
 	int (*link_update)(struct net_device *, struct fixed_phy_status *);
@@ -48,12 +45,10 @@ static struct fixed_mdio_bus platform_fmb = {
 	.phys = LIST_HEAD_INIT(platform_fmb.phys),
 };
 
-static void fixed_phy_update_regs(struct fixed_phy *fp)
+static void fixed_phy_update(struct fixed_phy *fp)
 {
 	if (gpio_is_valid(fp->link_gpio))
 		fp->status.link = !!gpio_get_value_cansleep(fp->link_gpio);
-
-	swphy_update_regs(fp->regs, &fp->status);
 }
 
 static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
@@ -61,29 +56,15 @@ 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);
+				fixed_phy_update(fp);
 			}
-			return fp->regs[reg_num];
+			return swphy_read_reg(reg_num, &fp->status);
 		}
 	}
 
@@ -143,7 +124,7 @@ 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);
 			return 0;
 		}
 	}
@@ -168,8 +149,6 @@ int fixed_phy_add(unsigned int irq, int phy_addr,
 	if (!fp)
 		return -ENOMEM;
 
-	memset(fp->regs, 0xFF,  sizeof(fp->regs[0]) * MII_REGS_NUM);
-
 	if (irq != PHY_POLL)
 		fmb->mii_bus->irq[phy_addr] = irq;
 
@@ -184,7 +163,7 @@ int fixed_phy_add(unsigned int irq, int phy_addr,
 			goto err_regs;
 	}
 
-	fixed_phy_update_regs(fp);
+	fixed_phy_update(fp);
 
 	list_add_tail(&fp->node, &fmb->phys);
 

drivers/net/phy/swphy.c

@@ -20,6 +20,8 @@
 
 #include "swphy.h"
 
+#define MII_REGS_NUM 29
+
 struct swmii_regs {
 	u16 bmcr;
 	u16 bmsr;
@@ -110,14 +112,13 @@ int swphy_validate_state(const struct fixed_phy_status *state)
 EXPORT_SYMBOL_GPL(swphy_validate_state);
 
 /**
- * swphy_update_regs - update MII register array with fixed phy state
- * @regs: array of 32 registers to update
+ * swphy_read_reg - return a MII register from the fixed phy state
+ * @reg: MII register
  * @state: fixed phy status
  *
- * Update the array of MII registers with the fixed phy link, speed,
- * duplex and pause mode settings.
+ * Return the MII @reg register generated from the fixed phy state @state.
  */
-void swphy_update_regs(u16 *regs, const struct fixed_phy_status *state)
+int swphy_read_reg(int reg, const struct fixed_phy_status *state)
 {
 	int speed_index, duplex_index;
 	u16 bmsr = BMSR_ANEGCAPABLE;
@@ -125,9 +126,12 @@ void swphy_update_regs(u16 *regs, const struct fixed_phy_status *state)
 	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;
+		return 0;
 
 	duplex_index = state->duplex ? SWMII_DUPLEX_FULL : SWMII_DUPLEX_HALF;
 
@@ -147,12 +151,29 @@ void swphy_update_regs(u16 *regs, const struct fixed_phy_status *state)
 			lpa |= LPA_PAUSE_ASYM;
 	}
 
-	regs[MII_PHYSID1] = 0;
-	regs[MII_PHYSID2] = 0;
+	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;
 
-	regs[MII_BMSR] = bmsr;
-	regs[MII_BMCR] = bmcr;
-	regs[MII_LPA] = lpa;
-	regs[MII_STAT1000] = 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_update_regs);
+EXPORT_SYMBOL_GPL(swphy_read_reg);

drivers/net/phy/swphy.h

@@ -4,6 +4,6 @@
 struct fixed_phy_status;
 
 int swphy_validate_state(const struct fixed_phy_status *state);
-void swphy_update_regs(u16 *regs, const struct fixed_phy_status *state);
+int swphy_read_reg(int reg, const struct fixed_phy_status *state);
 
 #endif