drivers: net: phy: xgene: Add MDIO driver

BugLink: https://launchpad.net/bugs/1632739

Currently, SGMII based 1G rely on the hardware registers for link state
and sometimes it's not reliable.  To get most accurate link state, this
interface has to use the MDIO bus to poll the PHY.

In X-Gene SoC, MDIO bus is shared across RGMII and SGMII based 1G
interfaces, so adding this driver to manage MDIO bus.  This driver
registers the mdio bus and registers the PHYs connected to it.
Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Tested-by: Fushen Chen <fchen@apm.com>
Tested-by: Toan Le <toanle@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(backported from commit 43b3cf66 yakkety)
Signed-off-by: Craig Magina <craig.magina@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>

drivers/net/phy/Kconfig

@@ -270,6 +270,12 @@ config MDIO_BCM_IPROC
 	  This module provides a driver for the MDIO busses found in the
 	  Broadcom iProc SoC's.
 
+config MDIO_XGENE
+	tristate "APM X-Gene SoC MDIO bus controller"
+	help
+	  This module provides a driver for the MDIO busses found in the
+	  APM X-Gene SoC's.
+
 endif # PHYLIB
 
 config MICREL_KS8995MA

drivers/net/phy/Makefile

@@ -44,3 +44,4 @@ obj-$(CONFIG_MDIO_MOXART)	+= mdio-moxart.o
 obj-$(CONFIG_MDIO_BCM_UNIMAC)	+= mdio-bcm-unimac.o
 obj-$(CONFIG_MICROCHIP_PHY)	+= microchip.o
 obj-$(CONFIG_MDIO_BCM_IPROC)	+= mdio-bcm-iproc.o
+obj-$(CONFIG_MDIO_XGENE)	+= mdio-xgene.o

drivers/net/phy/mdio-xgene.h

+/* Applied Micro X-Gene SoC MDIO Driver
+ *
+ * Copyright (c) 2016, Applied Micro Circuits Corporation
+ * Author: Iyappan Subramanian <isubramanian@apm.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __MDIO_XGENE_H__
+#define __MDIO_XGENE_H__
+
+#define BLOCK_XG_MDIO_CSR_OFFSET	0x5000
+#define BLOCK_DIAG_CSR_OFFSET		0xd000
+#define XGENET_CONFIG_REG_ADDR		0x20
+
+#define MAC_ADDR_REG_OFFSET		0x00
+#define MAC_COMMAND_REG_OFFSET		0x04
+#define MAC_WRITE_REG_OFFSET		0x08
+#define MAC_READ_REG_OFFSET		0x0c
+#define MAC_COMMAND_DONE_REG_OFFSET	0x10
+
+#define CLKEN_OFFSET			0x08
+#define SRST_OFFSET			0x00
+
+#define MENET_CFG_MEM_RAM_SHUTDOWN_ADDR	0x70
+#define MENET_BLOCK_MEM_RDY_ADDR	0x74
+
+#define MAC_CONFIG_1_ADDR		0x00
+#define MII_MGMT_COMMAND_ADDR		0x24
+#define MII_MGMT_ADDRESS_ADDR		0x28
+#define MII_MGMT_CONTROL_ADDR		0x2c
+#define MII_MGMT_STATUS_ADDR		0x30
+#define MII_MGMT_INDICATORS_ADDR	0x34
+#define SOFT_RESET			BIT(31)
+
+#define MII_MGMT_CONFIG_ADDR            0x20
+#define MII_MGMT_COMMAND_ADDR           0x24
+#define MII_MGMT_ADDRESS_ADDR           0x28
+#define MII_MGMT_CONTROL_ADDR           0x2c
+#define MII_MGMT_STATUS_ADDR            0x30
+#define MII_MGMT_INDICATORS_ADDR        0x34
+
+#define MIIM_COMMAND_ADDR               0x20
+#define MIIM_FIELD_ADDR                 0x24
+#define MIIM_CONFIGURATION_ADDR         0x28
+#define MIIM_LINKFAILVECTOR_ADDR        0x2c
+#define MIIM_INDICATOR_ADDR             0x30
+#define MIIMRD_FIELD_ADDR               0x34
+
+#define MDIO_CSR_OFFSET			0x5000
+
+#define REG_ADDR_POS			0
+#define REG_ADDR_LEN			5
+#define PHY_ADDR_POS			8
+#define PHY_ADDR_LEN			5
+
+#define HSTMIIMWRDAT_POS		0
+#define HSTMIIMWRDAT_LEN		16
+#define HSTPHYADX_POS			23
+#define HSTPHYADX_LEN			5
+#define HSTREGADX_POS			18
+#define HSTREGADX_LEN			5
+#define HSTLDCMD			BIT(3)
+#define HSTMIIMCMD_POS			0
+#define HSTMIIMCMD_LEN			3
+
+#define BUSY_MASK			BIT(0)
+#define READ_CYCLE_MASK			BIT(0)
+
+enum xgene_enet_cmd {
+	XGENE_ENET_WR_CMD = BIT(31),
+	XGENE_ENET_RD_CMD = BIT(30)
+};
+
+enum {
+	MIIM_CMD_IDLE,
+	MIIM_CMD_LEGACY_WRITE,
+	MIIM_CMD_LEGACY_READ,
+};
+
+enum xgene_mdio_id {
+	XGENE_MDIO_RGMII = 1,
+	XGENE_MDIO_XFI
+};
+
+struct xgene_mdio_pdata {
+	struct clk *clk;
+	struct device *dev;
+	void __iomem *mac_csr_addr;
+	void __iomem *diag_csr_addr;
+	void __iomem *mdio_csr_addr;
+	struct mii_bus *mdio_bus;
+	int mdio_id;
+};
+
+/* Set the specified value into a bit-field defined by its starting position
+ * and length within a single u64.
+ */
+static inline u64 xgene_enet_set_field_value(int pos, int len, u64 val)
+{
+	return (val & ((1ULL << len) - 1)) << pos;
+}
+
+#define SET_VAL(field, val) \
+		xgene_enet_set_field_value(field ## _POS, field ## _LEN, val)
+
+#define SET_BIT(field) \
+		xgene_enet_set_field_value(field ## _POS, 1, 1)
+
+/* Get the value from a bit-field defined by its starting position
+ * and length within the specified u64.
+ */
+static inline u64 xgene_enet_get_field_value(int pos, int len, u64 src)
+{
+	return (src >> pos) & ((1ULL << len) - 1);
+}
+
+#define GET_VAL(field, src) \
+		xgene_enet_get_field_value(field ## _POS, field ## _LEN, src)
+
+#define GET_BIT(field, src) \
+		xgene_enet_get_field_value(field ## _POS, 1, src)
+
+static const struct of_device_id xgene_mdio_of_match[];
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id xgene_mdio_acpi_match[];
+#endif
+int xgene_mdio_rgmii_read(struct mii_bus *bus, int phy_id, int reg);
+int xgene_mdio_rgmii_write(struct mii_bus *bus, int phy_id, int reg, u16 data);
+struct phy_device *xgene_enet_phy_register(struct mii_bus *bus, int phy_addr);
+
+#endif  /* __MDIO_XGENE_H__ */