phy: mdio-octeon: Refactor into two files/modules

A follow-on patch uses PCI probing to find the Thunder MDIO hardware.
In preparation for this, split out the common code into a new file
mdio-cavium.c, which will be used by both the existing OCTEON driver,
and the new Thunder PCI based driver.

As part of the refactoring simplify the struct cavium_mdiobus by
removing fields that are only ever used in the probe function and can
just as well be local variables.

Use readq/writeq in preference to readq_relaxed/writeq_relaxed as the
relaxed form was an optimization for an early chip revision, and the
MDIO drivers are not performance bottlenecks that need optimization in
the first place.

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 149 insertions, 0 deletions

diff --git a/drivers/net/phy/mdio-cavium.c b/drivers/net/phy/mdio-cavium.c
new file mode 100644
index 000000000000..e796ee121eac
--- /dev/null
+++ b/drivers/net/phy/mdio-cavium.c
@@ -0,0 +1,149 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2009-2016 Cavium, Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/phy.h>
+#include <linux/io.h>
+
+#include "mdio-cavium.h"
+
+static void cavium_mdiobus_set_mode(struct cavium_mdiobus *p,
+				    enum cavium_mdiobus_mode m)
+{
+	union cvmx_smix_clk smi_clk;
+
+	if (m == p->mode)
+		return;
+
+	smi_clk.u64 = oct_mdio_readq(p->register_base + SMI_CLK);
+	smi_clk.s.mode = (m == C45) ? 1 : 0;
+	smi_clk.s.preamble = 1;
+	oct_mdio_writeq(smi_clk.u64, p->register_base + SMI_CLK);
+	p->mode = m;
+}
+
+static int cavium_mdiobus_c45_addr(struct cavium_mdiobus *p,
+				   int phy_id, int regnum)
+{
+	union cvmx_smix_cmd smi_cmd;
+	union cvmx_smix_wr_dat smi_wr;
+	int timeout = 1000;
+
+	cavium_mdiobus_set_mode(p, C45);
+
+	smi_wr.u64 = 0;
+	smi_wr.s.dat = regnum & 0xffff;
+	oct_mdio_writeq(smi_wr.u64, p->register_base + SMI_WR_DAT);
+
+	regnum = (regnum >> 16) & 0x1f;
+
+	smi_cmd.u64 = 0;
+	smi_cmd.s.phy_op = 0; /* MDIO_CLAUSE_45_ADDRESS */
+	smi_cmd.s.phy_adr = phy_id;
+	smi_cmd.s.reg_adr = regnum;
+	oct_mdio_writeq(smi_cmd.u64, p->register_base + SMI_CMD);
+
+	do {
+		/* Wait 1000 clocks so we don't saturate the RSL bus
+		 * doing reads.
+		 */
+		__delay(1000);
+		smi_wr.u64 = oct_mdio_readq(p->register_base + SMI_WR_DAT);
+	} while (smi_wr.s.pending && --timeout);
+
+	if (timeout <= 0)
+		return -EIO;
+	return 0;
+}
+
+int cavium_mdiobus_read(struct mii_bus *bus, int phy_id, int regnum)
+{
+	struct cavium_mdiobus *p = bus->priv;
+	union cvmx_smix_cmd smi_cmd;
+	union cvmx_smix_rd_dat smi_rd;
+	unsigned int op = 1; /* MDIO_CLAUSE_22_READ */
+	int timeout = 1000;
+
+	if (regnum & MII_ADDR_C45) {
+		int r = cavium_mdiobus_c45_addr(p, phy_id, regnum);
+
+		if (r < 0)
+			return r;
+
+		regnum = (regnum >> 16) & 0x1f;
+		op = 3; /* MDIO_CLAUSE_45_READ */
+	} else {
+		cavium_mdiobus_set_mode(p, C22);
+	}
+
+	smi_cmd.u64 = 0;
+	smi_cmd.s.phy_op = op;
+	smi_cmd.s.phy_adr = phy_id;
+	smi_cmd.s.reg_adr = regnum;
+	oct_mdio_writeq(smi_cmd.u64, p->register_base + SMI_CMD);
+
+	do {
+		/* Wait 1000 clocks so we don't saturate the RSL bus
+		 * doing reads.
+		 */
+		__delay(1000);
+		smi_rd.u64 = oct_mdio_readq(p->register_base + SMI_RD_DAT);
+	} while (smi_rd.s.pending && --timeout);
+
+	if (smi_rd.s.val)
+		return smi_rd.s.dat;
+	else
+		return -EIO;
+}
+EXPORT_SYMBOL(cavium_mdiobus_read);
+
+int cavium_mdiobus_write(struct mii_bus *bus, int phy_id, int regnum, u16 val)
+{
+	struct cavium_mdiobus *p = bus->priv;
+	union cvmx_smix_cmd smi_cmd;
+	union cvmx_smix_wr_dat smi_wr;
+	unsigned int op = 0; /* MDIO_CLAUSE_22_WRITE */
+	int timeout = 1000;
+
+	if (regnum & MII_ADDR_C45) {
+		int r = cavium_mdiobus_c45_addr(p, phy_id, regnum);
+
+		if (r < 0)
+			return r;
+
+		regnum = (regnum >> 16) & 0x1f;
+		op = 1; /* MDIO_CLAUSE_45_WRITE */
+	} else {
+		cavium_mdiobus_set_mode(p, C22);
+	}
+
+	smi_wr.u64 = 0;
+	smi_wr.s.dat = val;
+	oct_mdio_writeq(smi_wr.u64, p->register_base + SMI_WR_DAT);
+
+	smi_cmd.u64 = 0;
+	smi_cmd.s.phy_op = op;
+	smi_cmd.s.phy_adr = phy_id;
+	smi_cmd.s.reg_adr = regnum;
+	oct_mdio_writeq(smi_cmd.u64, p->register_base + SMI_CMD);
+
+	do {
+		/* Wait 1000 clocks so we don't saturate the RSL bus
+		 * doing reads.
+		 */
+		__delay(1000);
+		smi_wr.u64 = oct_mdio_readq(p->register_base + SMI_WR_DAT);
+	} while (smi_wr.s.pending && --timeout);
+
+	if (timeout <= 0)
+		return -EIO;
+
+	return 0;
+}
+EXPORT_SYMBOL(cavium_mdiobus_write);