net: dsa: ksz: Add Microchip KSZ8795 DSA driver

Add Microchip KSZ8795 DSA driver.

Signed-off-by: Tristram Ha <Tristram.Ha@microchip.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: David S. Miller <davem@davemloft.net>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Tristram Ha <Tristram.Ha@microchip.com>
Cc: Vivien Didelot <vivien.didelot@gmail.com>
Cc: Woojung Huh <woojung.huh@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/microchip/Kconfig

@@ -16,3 +16,20 @@ config NET_DSA_MICROCHIP_KSZ9477_SPI
 	select REGMAP_SPI
 	help
 	  Select to enable support for registering switches configured through SPI.
+
+menuconfig NET_DSA_MICROCHIP_KSZ8795
+	tristate "Microchip KSZ8795 series switch support"
+	depends on NET_DSA
+	select NET_DSA_MICROCHIP_KSZ_COMMON
+	help
+	  This driver adds support for Microchip KSZ8795 switch chips.
+
+config NET_DSA_MICROCHIP_KSZ8795_SPI
+	tristate "KSZ8795 series SPI connected switch driver"
+	depends on NET_DSA_MICROCHIP_KSZ8795 && SPI
+	select REGMAP_SPI
+	help
+	  This driver accesses KSZ8795 chip through SPI.
+
+	  It is required to use the KSZ8795 switch driver as the only access
+	  is through SPI.

drivers/net/dsa/microchip/Makefile

@@ -2,3 +2,5 @@
 obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ_COMMON)	+= ksz_common.o
 obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ9477)		+= ksz9477.o
 obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ9477_SPI)	+= ksz9477_spi.o
+obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ8795)		+= ksz8795.o
+obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ8795_SPI)	+= ksz8795_spi.o

drivers/net/dsa/microchip/ksz8795_spi.c

@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Microchip KSZ8795 series register access through SPI
+ *
+ * Copyright (C) 2017 Microchip Technology Inc.
+ *	Tristram Ha <Tristram.Ha@microchip.com>
+ */
+
+#include <asm/unaligned.h>
+
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+#include "ksz_priv.h"
+#include "ksz_common.h"
+
+#define SPI_ADDR_SHIFT			12
+#define SPI_ADDR_ALIGN			3
+#define SPI_TURNAROUND_SHIFT		1
+
+KSZ_REGMAP_TABLE(ksz8795, 16, SPI_ADDR_SHIFT,
+		 SPI_TURNAROUND_SHIFT, SPI_ADDR_ALIGN);
+
+static int ksz8795_spi_probe(struct spi_device *spi)
+{
+	struct ksz_device *dev;
+	int i, ret;
+
+	dev = ksz_switch_alloc(&spi->dev, spi);
+	if (!dev)
+		return -ENOMEM;
+
+	for (i = 0; i < ARRAY_SIZE(ksz8795_regmap_config); i++) {
+		dev->regmap[i] = devm_regmap_init_spi(spi,
+						      &ksz8795_regmap_config
+						      [i]);
+		if (IS_ERR(dev->regmap[i])) {
+			ret = PTR_ERR(dev->regmap[i]);
+			dev_err(&spi->dev,
+				"Failed to initialize regmap%i: %d\n",
+				ksz8795_regmap_config[i].val_bits, ret);
+			return ret;
+		}
+	}
+
+	if (spi->dev.platform_data)
+		dev->pdata = spi->dev.platform_data;
+
+	ret = ksz8795_switch_register(dev);
+
+	/* Main DSA driver may not be started yet. */
+	if (ret)
+		return ret;
+
+	spi_set_drvdata(spi, dev);
+
+	return 0;
+}
+
+static int ksz8795_spi_remove(struct spi_device *spi)
+{
+	struct ksz_device *dev = spi_get_drvdata(spi);
+
+	if (dev)
+		ksz_switch_remove(dev);
+
+	return 0;
+}
+
+static void ksz8795_spi_shutdown(struct spi_device *spi)
+{
+	struct ksz_device *dev = spi_get_drvdata(spi);
+
+	if (dev && dev->dev_ops->shutdown)
+		dev->dev_ops->shutdown(dev);
+}
+
+static const struct of_device_id ksz8795_dt_ids[] = {
+	{ .compatible = "microchip,ksz8765" },
+	{ .compatible = "microchip,ksz8794" },
+	{ .compatible = "microchip,ksz8795" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ksz8795_dt_ids);
+
+static struct spi_driver ksz8795_spi_driver = {
+	.driver = {
+		.name	= "ksz8795-switch",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(ksz8795_dt_ids),
+	},
+	.probe	= ksz8795_spi_probe,
+	.remove	= ksz8795_spi_remove,
+	.shutdown = ksz8795_spi_shutdown,
+};
+
+module_spi_driver(ksz8795_spi_driver);
+
+MODULE_AUTHOR("Tristram Ha <Tristram.Ha@microchip.com>");
+MODULE_DESCRIPTION("Microchip KSZ8795 Series Switch SPI Driver");
+MODULE_LICENSE("GPL");

drivers/net/dsa/microchip/ksz_common.c

@@ -373,7 +373,8 @@ int ksz_enable_port(struct dsa_switch *ds, int port, struct phy_device *phy)
 
 	/* setup slave port */
 	dev->dev_ops->port_setup(dev, port, false);
-	dev->dev_ops->phy_setup(dev, port, phy);
+	if (dev->dev_ops->phy_setup)
+		dev->dev_ops->phy_setup(dev, port, phy);
 
 	/* port_stp_state_set() will be called after to enable the port so
 	 * there is no need to do anything.

drivers/net/dsa/microchip/ksz_common.h

@@ -68,6 +68,22 @@ static inline int ksz_read32(struct ksz_device *dev, u32 reg, u32 *val)
 	return ret;
 }
 
+static inline int ksz_read64(struct ksz_device *dev, u32 reg, u64 *val)
+{
+	u32 value[2];
+	int ret;
+
+	ret = regmap_bulk_read(dev->regmap[2], reg, value, 2);
+	if (!ret) {
+		/* Ick! ToDo: Add 64bit R/W to regmap on 32bit systems */
+		value[0] = swab32(value[0]);
+		value[1] = swab32(value[1]);
+		*val = swab64((u64)*value);
+	}
+
+	return ret;
+}
+
 static inline int ksz_write8(struct ksz_device *dev, u32 reg, u8 value)
 {
 	return regmap_write(dev->regmap[0], reg, value);
@@ -83,6 +99,18 @@ static inline int ksz_write32(struct ksz_device *dev, u32 reg, u32 value)
 	return regmap_write(dev->regmap[2], reg, value);
 }
 
+static inline int ksz_write64(struct ksz_device *dev, u32 reg, u64 value)
+{
+	u32 val[2];
+
+	/* Ick! ToDo: Add 64bit R/W to regmap on 32bit systems */
+	value = swab64(value);
+	val[0] = swab32(value & 0xffffffffULL);
+	val[1] = swab32(value >> 32ULL);
+
+	return regmap_bulk_write(dev->regmap[2], reg, val, 2);
+}
+
 static inline void ksz_pread8(struct ksz_device *dev, int port, int offset,
 			      u8 *data)
 {

drivers/net/dsa/microchip/ksz_priv.h

@@ -150,6 +150,7 @@ int ksz_switch_register(struct ksz_device *dev,
 			const struct ksz_dev_ops *ops);
 void ksz_switch_remove(struct ksz_device *dev);
 
+int ksz8795_switch_register(struct ksz_device *dev);
 int ksz9477_switch_register(struct ksz_device *dev);
 
 #endif