1 files changed, 74 insertions, 0 deletions
diff --git a/drivers/net/mscc_eswitch/mscc_miim.c b/drivers/net/mscc_eswitch/mscc_miim.c
new file mode 100644
index 00000000000..419dcc1dd6c
--- /dev/null
+++ b/drivers/net/mscc_eswitch/mscc_miim.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Copyright (c) 2018 Microsemi Corporation
+ */
+
+#include <miiphy.h>
+#include <wait_bit.h>
+#include "mscc_miim.h"
+
+#define MIIM_STATUS			0x0
+#define		MIIM_STAT_BUSY			BIT(3)
+#define MIIM_CMD			0x8
+#define		MIIM_CMD_SCAN		BIT(0)
+#define		MIIM_CMD_OPR_WRITE	BIT(1)
+#define		MIIM_CMD_OPR_READ	BIT(2)
+#define		MIIM_CMD_SINGLE_SCAN	BIT(3)
+#define		MIIM_CMD_WRDATA(x)	((x) << 4)
+#define		MIIM_CMD_REGAD(x)	((x) << 20)
+#define		MIIM_CMD_PHYAD(x)	((x) << 25)
+#define		MIIM_CMD_VLD		BIT(31)
+#define MIIM_DATA			0xC
+#define		MIIM_DATA_ERROR		(0x2 << 16)
+
+static int mscc_miim_wait_ready(struct mscc_miim_dev *miim)
+{
+	return wait_for_bit_le32(miim->regs + MIIM_STATUS, MIIM_STAT_BUSY,
+				 false, 250, false);
+}
+
+int mscc_miim_read(struct mii_dev *bus, int addr, int devad, int reg)
+{
+	struct mscc_miim_dev *miim = (struct mscc_miim_dev *)bus->priv;
+	u32 val;
+	int ret;
+
+	ret = mscc_miim_wait_ready(miim);
+	if (ret)
+		goto out;
+
+	writel(MIIM_CMD_VLD | MIIM_CMD_PHYAD(addr) |
+	       MIIM_CMD_REGAD(reg) | MIIM_CMD_OPR_READ,
+	       miim->regs + MIIM_CMD);
+
+	ret = mscc_miim_wait_ready(miim);
+	if (ret)
+		goto out;
+
+	val = readl(miim->regs + MIIM_DATA);
+	if (val & MIIM_DATA_ERROR) {
+		ret = -EIO;
+		goto out;
+	}
+
+	ret = val & 0xFFFF;
+ out:
+	return ret;
+}
+
+int mscc_miim_write(struct mii_dev *bus, int addr, int devad, int reg,
+		    u16 val)
+{
+	struct mscc_miim_dev *miim = (struct mscc_miim_dev *)bus->priv;
+	int ret;
+
+	ret = mscc_miim_wait_ready(miim);
+	if (ret < 0)
+		goto out;
+
+	writel(MIIM_CMD_VLD | MIIM_CMD_PHYAD(addr) |
+	       MIIM_CMD_REGAD(reg) | MIIM_CMD_WRDATA(val) |
+	       MIIM_CMD_OPR_WRITE, miim->regs + MIIM_CMD);
+ out:
+	return ret;
+}