[Patch net-next v13 07/13] net: dsa: microchip: add LAN937x SPI driver

[Arun Ramadoss <arun.ramadoss@microchip.com>]

This patch add the SPI driver for the LAN937x switches. It uses the
lan937x_main.c and lan937x_dev.c functions.

Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
---
 drivers/net/dsa/microchip/Makefile      |   1 +
 drivers/net/dsa/microchip/ksz_common.h  |   1 +
 drivers/net/dsa/microchip/lan937x_dev.c |   7 +
 drivers/net/dsa/microchip/lan937x_spi.c | 236 ++++++++++++++++++++++++
 4 files changed, 245 insertions(+)
 create mode 100644 drivers/net/dsa/microchip/lan937x_spi.c

diff --git a/drivers/net/dsa/microchip/Makefile b/drivers/net/dsa/microchip/Makefile
index d32ff38dc240..28d8eb62a795 100644
--- a/drivers/net/dsa/microchip/Makefile
+++ b/drivers/net/dsa/microchip/Makefile
@@ -10,3 +10,4 @@ obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ8863_SMI)	+= ksz8863_smi.o
 obj-$(CONFIG_NET_DSA_MICROCHIP_LAN937X)		+= lan937x.o
 lan937x-objs := lan937x_dev.o
 lan937x-objs += lan937x_main.o
+lan937x-objs += lan937x_spi.o
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index 5671f580948d..fd9e0705d2d2 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -151,6 +151,7 @@ void ksz_switch_remove(struct ksz_device *dev);
 int ksz8_switch_register(struct ksz_device *dev);
 int ksz9477_switch_register(struct ksz_device *dev);
 int lan937x_switch_register(struct ksz_device *dev);
+int lan937x_check_device_id(struct ksz_device *dev);
 
 void ksz_update_port_member(struct ksz_device *dev, int port);
 void ksz_init_mib_timer(struct ksz_device *dev);
diff --git a/drivers/net/dsa/microchip/lan937x_dev.c b/drivers/net/dsa/microchip/lan937x_dev.c
index 3f1797cc1d16..f430a8711775 100644
--- a/drivers/net/dsa/microchip/lan937x_dev.c
+++ b/drivers/net/dsa/microchip/lan937x_dev.c
@@ -386,8 +386,15 @@ static int lan937x_mdio_register(struct ksz_device *dev)
 
 static int lan937x_switch_init(struct ksz_device *dev)
 {
+	int ret;
+
 	dev->ds->ops = &lan937x_switch_ops;
 
+	/* Check device tree */
+	ret = lan937x_check_device_id(dev);
+	if (ret < 0)
+		return ret;
+
 	dev->port_mask = (1 << dev->port_cnt) - 1;
 
 	dev->ports = devm_kzalloc(dev->dev,
diff --git a/drivers/net/dsa/microchip/lan937x_spi.c b/drivers/net/dsa/microchip/lan937x_spi.c
new file mode 100644
index 000000000000..a50dfcf27aff
--- /dev/null
+++ b/drivers/net/dsa/microchip/lan937x_spi.c
@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Microchip LAN937X switch driver register access through SPI
+ * Copyright (C) 2019-2021 Microchip Technology Inc.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+#include <linux/of_device.h>
+
+#include "ksz_common.h"
+
+#define SPI_ADDR_SHIFT 24
+#define SPI_ADDR_ALIGN 3
+#define SPI_TURNAROUND_SHIFT 5
+
+KSZ_REGMAP_TABLE(lan937x, 32, SPI_ADDR_SHIFT, SPI_TURNAROUND_SHIFT,
+		 SPI_ADDR_ALIGN);
+
+struct lan937x_chip_data {
+	u32 chip_id;
+	const char *dev_name;
+	int num_vlans;
+	int num_alus;
+	int num_statics;
+	int cpu_ports;
+	int port_cnt;
+};
+
+static const struct of_device_id lan937x_dt_ids[];
+
+static const struct lan937x_chip_data lan937x_switch_chips[] = {
+	{
+		.chip_id = 0x00937010,
+		.dev_name = "LAN9370",
+		.num_vlans = 4096,
+		.num_alus = 1024,
+		.num_statics = 256,
+		/* can be configured as cpu port */
+		.cpu_ports = 0x10,
+		/* total port count */
+		.port_cnt = 5,
+	},
+	{
+		.chip_id = 0x00937110,
+		.dev_name = "LAN9371",
+		.num_vlans = 4096,
+		.num_alus = 1024,
+		.num_statics = 256,
+		/* can be configured as cpu port */
+		.cpu_ports = 0x30,
+		/* total port count */
+		.port_cnt = 6,
+	},
+	{
+		.chip_id = 0x00937210,
+		.dev_name = "LAN9372",
+		.num_vlans = 4096,
+		.num_alus = 1024,
+		.num_statics = 256,
+		/* can be configured as cpu port */
+		.cpu_ports = 0x30,
+		/* total port count */
+		.port_cnt = 8,
+	},
+	{
+		.chip_id = 0x00937310,
+		.dev_name = "LAN9373",
+		.num_vlans = 4096,
+		.num_alus = 1024,
+		.num_statics = 256,
+		/* can be configured as cpu port */
+		.cpu_ports = 0x38,
+		/* total port count */
+		.port_cnt = 5,
+	},
+	{
+		.chip_id = 0x00937410,
+		.dev_name = "LAN9374",
+		.num_vlans = 4096,
+		.num_alus = 1024,
+		.num_statics = 256,
+		/* can be configured as cpu port */
+		.cpu_ports = 0x30,
+		/* total port count */
+		.port_cnt = 8,
+	},
+};
+
+static int lan937x_spi_probe(struct spi_device *spi)
+{
+	struct regmap_config rc;
+	struct ksz_device *dev;
+	int i, ret;
+
+	dev = ksz_switch_alloc(&spi->dev, spi);
+	if (!dev)
+		return -ENOMEM;
+
+	for (i = 0; i < ARRAY_SIZE(lan937x_regmap_config); i++) {
+		rc = lan937x_regmap_config[i];
+		rc.lock_arg = &dev->regmap_mutex;
+		dev->regmap[i] = devm_regmap_init_spi(spi, &rc);
+
+		if (IS_ERR(dev->regmap[i])) {
+			ret = PTR_ERR(dev->regmap[i]);
+			dev_err(&spi->dev,
+				"Failed to initialize regmap%i: %d\n",
+				lan937x_regmap_config[i].val_bits, ret);
+			return ret;
+		}
+	}
+
+	if (spi->dev.platform_data)
+		dev->pdata = spi->dev.platform_data;
+
+	ret = lan937x_switch_register(dev);
+	/* Main DSA driver may not be started yet. */
+	if (ret)
+		return ret;
+
+	spi_set_drvdata(spi, dev);
+
+	return 0;
+}
+
+int lan937x_check_device_id(struct ksz_device *dev)
+{
+	const struct lan937x_chip_data *dt_chip_data;
+	const struct of_device_id *match;
+	int i;
+
+	dt_chip_data = of_device_get_match_data(dev->dev);
+
+	if (!dt_chip_data)
+		return -EINVAL;
+
+	for (match = lan937x_dt_ids; match->compatible[0]; match++) {
+		const struct lan937x_chip_data *chip_data = match->data;
+
+		/* Check for chip id */
+		if (chip_data->chip_id != dev->chip_id)
+			continue;
+
+		/* Check for Device Tree and Chip ID */
+		if (dt_chip_data->chip_id != dev->chip_id) {
+			dev_err(dev->dev,
+				"Device tree specifies chip %s but found %s, please fix it!\n",
+				dt_chip_data->dev_name, chip_data->dev_name);
+			return -ENODEV;
+		}
+
+		break;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(lan937x_switch_chips); i++) {
+		const struct lan937x_chip_data *chip = &lan937x_switch_chips[i];
+
+		if (dev->chip_id == chip->chip_id) {
+			dev->name = chip->dev_name;
+			dev->num_vlans = chip->num_vlans;
+			dev->num_alus = chip->num_alus;
+			dev->num_statics = chip->num_statics;
+			dev->port_cnt = chip->port_cnt;
+			dev->cpu_ports = chip->cpu_ports;
+			break;
+		}
+	}
+
+	/* no switch found */
+	if (!dev->port_cnt)
+		return -ENODEV;
+
+	return 0;
+}
+EXPORT_SYMBOL(lan937x_check_device_id);
+
+static void lan937x_spi_remove(struct spi_device *spi)
+{
+	struct ksz_device *dev = spi_get_drvdata(spi);
+
+	if (dev)
+		ksz_switch_remove(dev);
+
+	spi_set_drvdata(spi, NULL);
+}
+
+static void lan937x_spi_shutdown(struct spi_device *spi)
+{
+	struct ksz_device *dev = spi_get_drvdata(spi);
+
+	if (dev)
+		dsa_switch_shutdown(dev->ds);
+
+	spi_set_drvdata(spi, NULL);
+}
+
+static const struct of_device_id lan937x_dt_ids[] = {
+	{ .compatible = "microchip,lan9370", .data = &lan937x_switch_chips[0] },
+	{ .compatible = "microchip,lan9371", .data = &lan937x_switch_chips[1] },
+	{ .compatible = "microchip,lan9372", .data = &lan937x_switch_chips[2] },
+	{ .compatible = "microchip,lan9373", .data = &lan937x_switch_chips[3] },
+	{ .compatible = "microchip,lan9374", .data = &lan937x_switch_chips[4] },
+	{},
+};
+MODULE_DEVICE_TABLE(of, lan937x_dt_ids);
+
+static const struct spi_device_id lan937x_spi_ids[] = {
+	{ .name = "lan9370" },
+	{ .name = "lan9371" },
+	{ .name = "lan9372" },
+	{ .name = "lan9373" },
+	{ .name = "lan9374" },
+	{},
+};
+MODULE_DEVICE_TABLE(spi, lan937x_spi_ids);
+
+static struct spi_driver lan937x_spi_driver = {
+	.driver = {
+		.name	= "lan937x-switch",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(lan937x_dt_ids),
+	},
+	.probe	= lan937x_spi_probe,
+	.remove	= lan937x_spi_remove,
+	.shutdown = lan937x_spi_shutdown,
+	.id_table = lan937x_spi_ids,
+};
+
+module_spi_driver(lan937x_spi_driver);
+
+MODULE_ALIAS("spi:lan937x");
+
+MODULE_AUTHOR("Prasanna Vengateshan Varadharajan <Prasanna.Vengateshan@microchip.com>");
+MODULE_DESCRIPTION("Microchip LAN937x Series Switch SPI access Driver");
+MODULE_LICENSE("GPL");
-- 
2.33.0