[PATCH v3 4/4] net: dsa: LAN9303: add MDIO managed mode support

From: Juergen Borleis
Date: Wed Apr 12 2017 - 10:02:44 EST


When the LAN9303 device is in MDIO manged mode, all register accesses must
be done via MDIO.

Please note: this code is compile time tested only due to the absence of such
configured hardware. It is based on a patch from Stefan Roese from 2014.

Signed-off-by: Juergen Borleis <jbe@xxxxxxxxxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
CC: devicetree@xxxxxxxxxxxxxxx
CC: robh+dt@xxxxxxxxxx
CC: mark.rutland@xxxxxxx
---
.../devicetree/bindings/net/dsa/lan9303.txt | 45 ++++++-
drivers/net/dsa/Kconfig | 8 ++
drivers/net/dsa/Makefile | 1 +
drivers/net/dsa/lan9303_mdio.c | 144 +++++++++++++++++++++
4 files changed, 197 insertions(+), 1 deletion(-)
create mode 100644 drivers/net/dsa/lan9303_mdio.c

diff --git a/Documentation/devicetree/bindings/net/dsa/lan9303.txt b/Documentation/devicetree/bindings/net/dsa/lan9303.txt
index 2edc2561467a7..04f2965a44676 100644
--- a/Documentation/devicetree/bindings/net/dsa/lan9303.txt
+++ b/Documentation/devicetree/bindings/net/dsa/lan9303.txt
@@ -3,7 +3,10 @@ SMSC/MicroChip LAN9303 three port ethernet switch

Required properties:

-- compatible: should be "smsc,lan9303-i2c"
+- compatible: should be
+ - "smsc,lan9303-i2c" for I2C managed mode
+ or
+ - "smsc,lan9303-mdio" for mdio managed mode

Optional properties:

@@ -60,3 +63,43 @@ I2C managed mode:
};
};
};
+
+MDIO managed mode:
+
+ master: masterdevice@X {
+ status = "okay";
+ phy-handle = <&switch>;
+
+ mdio {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ switch: switch-phy@0 {
+ compatible = "smsc,lan9303-mdio";
+ reg = <0>;
+ reset-gpios = <&gpio7 6 GPIO_ACTIVE_LOW>;
+ reset-duration = <100>;
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0 {
+ reg = <0>;
+ label = "cpu";
+ ethernet = <&master>;
+ };
+
+ port@1 { /* external port 1 */
+ reg = <1>;
+ label = "lan1;
+ };
+
+ port@2 { /* external port 2 */
+ reg = <2>;
+ label = "lan2";
+ };
+ };
+ };
+ };
+ };
diff --git a/drivers/net/dsa/Kconfig b/drivers/net/dsa/Kconfig
index 83887c68ef7a3..e52b298853474 100644
--- a/drivers/net/dsa/Kconfig
+++ b/drivers/net/dsa/Kconfig
@@ -67,4 +67,12 @@ config NET_DSA_SMSC_LAN9303_I2C
Enable access functions if the SMSC/Microchip LAN9303 is configured
for I2C managed mode.

+config NET_DSA_SMSC_LAN9303_MDIO
+ bool "MDIO managed mode"
+ depends on NET_DSA_SMSC_LAN9303
+ depends on OF_MDIO
+ ---help---
+ Enable access functions if the SMSC/Microchip LAN9303 is configured
+ for MDIO managed mode.
+
endmenu
diff --git a/drivers/net/dsa/Makefile b/drivers/net/dsa/Makefile
index e626aeba8525e..e782d9648bc8c 100644
--- a/drivers/net/dsa/Makefile
+++ b/drivers/net/dsa/Makefile
@@ -1,5 +1,6 @@
lan9303-objs-y := lan9303-core.o
lan9303-objs-$(CONFIG_NET_DSA_SMSC_LAN9303_I2C) += lan9303_i2c.o
+lan9303-objs-$(CONFIG_NET_DSA_SMSC_LAN9303_MDIO) += lan9303_mdio.o

obj-$(CONFIG_NET_DSA_MV88E6060) += mv88e6060.o
obj-$(CONFIG_NET_DSA_BCM_SF2) += bcm-sf2.o
diff --git a/drivers/net/dsa/lan9303_mdio.c b/drivers/net/dsa/lan9303_mdio.c
new file mode 100644
index 0000000000000..87c5cfa946a92
--- /dev/null
+++ b/drivers/net/dsa/lan9303_mdio.c
@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2017 Pengutronix, Juergen Borleis <kernel@xxxxxxxxxxxxxx>
+ *
+ * Partially based on a patch from
+ * Copyright (c) 2014 Stefan Roese <sr@xxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2, as published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mdio.h>
+#include <linux/phy.h>
+#include <linux/of.h>
+
+#include "lan9303.h"
+
+/* Generate phy-addr and -reg from the input address */
+#define PHY_ADDR(x) ((((x) >> 6) + 0x10) & 0x1f)
+#define PHY_REG(x) (((x) >> 1) & 0x1f)
+
+struct lan9303_mdio {
+ struct mdio_device *device;
+ struct lan9303 chip;
+};
+
+static void lan9303_mdio_real_write(struct mdio_device *mdio, int reg, u16 val)
+{
+ mdio->bus->write(mdio->bus, PHY_ADDR(reg), PHY_REG(reg), val);
+}
+
+static int lan9303_mdio_write(void *ctx, uint32_t reg, uint32_t val)
+{
+ struct lan9303_mdio *sw_dev = (struct lan9303_mdio *)ctx;
+
+ mutex_lock(&sw_dev->device->bus->mdio_lock);
+ lan9303_mdio_real_write(sw_dev->device, reg, val & 0xffff);
+ lan9303_mdio_real_write(sw_dev->device, reg + 2, (val >> 16) & 0xffff);
+ mutex_unlock(&sw_dev->device->bus->mdio_lock);
+
+ return 0;
+}
+
+static u16 lan9303_mdio_real_read(struct mdio_device *mdio, int reg)
+{
+ return mdio->bus->read(mdio->bus, PHY_ADDR(reg), PHY_REG(reg));
+}
+
+static int lan9303_mdio_read(void *ctx, uint32_t reg, uint32_t *val)
+{
+ struct lan9303_mdio *sw_dev = (struct lan9303_mdio *)ctx;
+
+ mutex_lock(&sw_dev->device->bus->mdio_lock);
+ *val = lan9303_mdio_real_read(sw_dev->device, reg);
+ *val |= (lan9303_mdio_real_read(sw_dev->device, reg + 2) << 16);
+ mutex_unlock(&sw_dev->device->bus->mdio_lock);
+
+ return 0;
+}
+
+static const struct regmap_config lan9303_mdio_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 32,
+ .reg_stride = 1,
+ .can_multi_write = true,
+ .max_register = 0x0ff, /* address bits 0..1 are not used */
+ .reg_format_endian = REGMAP_ENDIAN_LITTLE,
+
+ .volatile_table = &lan9303_register_set,
+ .wr_table = &lan9303_register_set,
+ .rd_table = &lan9303_register_set,
+
+ .reg_read = lan9303_mdio_read,
+ .reg_write = lan9303_mdio_write,
+
+ .cache_type = REGCACHE_NONE,
+};
+
+static int lan9303_mdio_probe(struct mdio_device *mdiodev)
+{
+ struct lan9303_mdio *sw_dev;
+ int ret;
+
+ sw_dev = devm_kzalloc(&mdiodev->dev, sizeof(struct lan9303_mdio),
+ GFP_KERNEL);
+ if (!sw_dev)
+ return -ENOMEM;
+
+ sw_dev->chip.regmap = devm_regmap_init(&mdiodev->dev, NULL, sw_dev,
+ &lan9303_mdio_regmap_config);
+ if (IS_ERR(sw_dev->chip.regmap)) {
+ ret = PTR_ERR(sw_dev->chip.regmap);
+ dev_err(&mdiodev->dev, "regmap init failed: %d\n", ret);
+ return ret;
+ }
+
+ /* link forward and backward */
+ sw_dev->device = mdiodev;
+ dev_set_drvdata(&mdiodev->dev, sw_dev);
+ sw_dev->chip.dev = &mdiodev->dev;
+
+ ret = lan9303_probe(&sw_dev->chip, mdiodev->dev.of_node);
+ if (ret != 0)
+ return ret;
+
+ dev_info(&mdiodev->dev, "LAN9303 MDIO driver loaded successfully\n");
+
+ return 0;
+}
+
+static void lan9303_mdio_remove(struct mdio_device *mdiodev)
+{
+ struct lan9303_mdio *sw_dev = dev_get_drvdata(&mdiodev->dev);
+
+ if (!sw_dev)
+ return;
+
+ lan9303_remove(&sw_dev->chip);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static const struct of_device_id lan9303_mdio_of_match[] = {
+ { .compatible = "smsc,lan9303-mdio" },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, lan9303_mdio_of_match);
+
+static struct mdio_driver lan9303_mdio_driver = {
+ .mdiodrv.driver = {
+ .name = "LAN9303_MDIO",
+ .of_match_table = of_match_ptr(lan9303_mdio_of_match),
+ },
+ .probe = lan9303_mdio_probe,
+ .remove = lan9303_mdio_remove,
+};
+mdio_module_driver(lan9303_mdio_driver);
--
2.11.0