dsa: add DSA switch driver for Microchip KSZ9477

The KSZ9477 is a fully integrated layer 2, managed, 7 ports GigE switch
with numerous advanced features. 5 ports incorporate 10/100/1000 Mbps PHYs.
The other 2 ports have interfaces that can be configured as SGMII, RGMII, MII
or RMII. Either of these may connect directly to a host processor or
to an external PHY. The SGMII port may interface to a fiber optic transceiver.

This driver currently supports vlan, fdb, mdb & mirror dsa switch operations.

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Woojung Huh <Woojung.Huh@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 216 insertions, 0 deletions

diff --git a/drivers/net/dsa/microchip/ksz_spi.c b/drivers/net/dsa/microchip/ksz_spi.c
new file mode 100644
index 000000000000..c51946983bed
--- /dev/null
+++ b/drivers/net/dsa/microchip/ksz_spi.c
@@ -0,0 +1,216 @@
+/*
+ * Microchip KSZ series register access through SPI
+ *
+ * Copyright (C) 2017
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <asm/unaligned.h>
+
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+
+#include "ksz_priv.h"
+
+/* SPI frame opcodes */
+#define KS_SPIOP_RD			3
+#define KS_SPIOP_WR			2
+
+#define SPI_ADDR_SHIFT			24
+#define SPI_ADDR_MASK			(BIT(SPI_ADDR_SHIFT) - 1)
+#define SPI_TURNAROUND_SHIFT		5
+
+static int ksz_spi_read_reg(struct spi_device *spi, u32 reg, u8 *val,
+			    unsigned int len)
+{
+	u32 txbuf;
+	int ret;
+
+	txbuf = reg & SPI_ADDR_MASK;
+	txbuf |= KS_SPIOP_RD << SPI_ADDR_SHIFT;
+	txbuf <<= SPI_TURNAROUND_SHIFT;
+	txbuf = cpu_to_be32(txbuf);
+
+	ret = spi_write_then_read(spi, &txbuf, 4, val, len);
+	return ret;
+}
+
+static int ksz_spi_read(struct ksz_device *dev, u32 reg, u8 *data,
+			unsigned int len)
+{
+	struct spi_device *spi = dev->priv;
+
+	return ksz_spi_read_reg(spi, reg, data, len);
+}
+
+static int ksz_spi_read8(struct ksz_device *dev, u32 reg, u8 *val)
+{
+	return ksz_spi_read(dev, reg, val, 1);
+}
+
+static int ksz_spi_read16(struct ksz_device *dev, u32 reg, u16 *val)
+{
+	int ret = ksz_spi_read(dev, reg, (u8 *)val, 2);
+
+	if (!ret)
+		*val = be16_to_cpu(*val);
+
+	return ret;
+}
+
+static int ksz_spi_read24(struct ksz_device *dev, u32 reg, u32 *val)
+{
+	int ret;
+
+	*val = 0;
+	ret = ksz_spi_read(dev, reg, (u8 *)val, 3);
+	if (!ret) {
+		*val = be32_to_cpu(*val);
+		/* convert to 24bit */
+		*val >>= 8;
+	}
+
+	return ret;
+}
+
+static int ksz_spi_read32(struct ksz_device *dev, u32 reg, u32 *val)
+{
+	int ret = ksz_spi_read(dev, reg, (u8 *)val, 4);
+
+	if (!ret)
+		*val = be32_to_cpu(*val);
+
+	return ret;
+}
+
+static int ksz_spi_write_reg(struct spi_device *spi, u32 reg, u8 *val,
+			     unsigned int len)
+{
+	u32 txbuf;
+	u8 data[12];
+	int i;
+
+	txbuf = reg & SPI_ADDR_MASK;
+	txbuf |= (KS_SPIOP_WR << SPI_ADDR_SHIFT);
+	txbuf <<= SPI_TURNAROUND_SHIFT;
+	txbuf = cpu_to_be32(txbuf);
+
+	data[0] = txbuf & 0xFF;
+	data[1] = (txbuf & 0xFF00) >> 8;
+	data[2] = (txbuf & 0xFF0000) >> 16;
+	data[3] = (txbuf & 0xFF000000) >> 24;
+	for (i = 0; i < len; i++)
+		data[i + 4] = val[i];
+
+	return spi_write(spi, &data, 4 + len);
+}
+
+static int ksz_spi_write8(struct ksz_device *dev, u32 reg, u8 value)
+{
+	struct spi_device *spi = dev->priv;
+
+	return ksz_spi_write_reg(spi, reg, &value, 1);
+}
+
+static int ksz_spi_write16(struct ksz_device *dev, u32 reg, u16 value)
+{
+	struct spi_device *spi = dev->priv;
+
+	value = cpu_to_be16(value);
+	return ksz_spi_write_reg(spi, reg, (u8 *)&value, 2);
+}
+
+static int ksz_spi_write24(struct ksz_device *dev, u32 reg, u32 value)
+{
+	struct spi_device *spi = dev->priv;
+
+	/* make it to big endian 24bit from MSB */
+	value <<= 8;
+	value = cpu_to_be32(value);
+	return ksz_spi_write_reg(spi, reg, (u8 *)&value, 3);
+}
+
+static int ksz_spi_write32(struct ksz_device *dev, u32 reg, u32 value)
+{
+	struct spi_device *spi = dev->priv;
+
+	value = cpu_to_be32(value);
+	return ksz_spi_write_reg(spi, reg, (u8 *)&value, 4);
+}
+
+static const struct ksz_io_ops ksz_spi_ops = {
+	.read8 = ksz_spi_read8,
+	.read16 = ksz_spi_read16,
+	.read24 = ksz_spi_read24,
+	.read32 = ksz_spi_read32,
+	.write8 = ksz_spi_write8,
+	.write16 = ksz_spi_write16,
+	.write24 = ksz_spi_write24,
+	.write32 = ksz_spi_write32,
+};
+
+static int ksz_spi_probe(struct spi_device *spi)
+{
+	struct ksz_device *dev;
+	int ret;
+
+	dev = ksz_switch_alloc(&spi->dev, &ksz_spi_ops, spi);
+	if (!dev)
+		return -ENOMEM;
+
+	if (spi->dev.platform_data)
+		dev->pdata = spi->dev.platform_data;
+
+	ret = ksz_switch_register(dev);
+	if (ret)
+		return ret;
+
+	spi_set_drvdata(spi, dev);
+
+	return 0;
+}
+
+static int ksz_spi_remove(struct spi_device *spi)
+{
+	struct ksz_device *dev = spi_get_drvdata(spi);
+
+	if (dev)
+		ksz_switch_remove(dev);
+
+	return 0;
+}
+
+static const struct of_device_id ksz_dt_ids[] = {
+	{ .compatible = "microchip,ksz9477" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ksz_dt_ids);
+
+static struct spi_driver ksz_spi_driver = {
+	.driver = {
+		.name	= "ksz9477-switch",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(ksz_dt_ids),
+	},
+	.probe	= ksz_spi_probe,
+	.remove	= ksz_spi_remove,
+};
+
+module_spi_driver(ksz_spi_driver);
+
+MODULE_AUTHOR("Woojung Huh <Woojung.Huh@microchip.com>");
+MODULE_DESCRIPTION("Microchip KSZ Series Switch SPI access Driver");
+MODULE_LICENSE("GPL");