net: Add MDIO bus driver for the Allwinner EMAC

This patch adds a separate driver for the MDIO interface of the
Allwinner ethernet controllers.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/devicetree/bindings/net/allwinner,sun4i-mdio.txt b/Documentation/devicetree/bindings/net/allwinner,sun4i-mdio.txt
new file mode 100644 (file)
index 0000000..00b9f9a
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/allwinner,sun4i-mdio.txt
@@ -0,0 +1,26 @@
+* Allwinner A10 MDIO Ethernet Controller interface
+
+Required properties:
+- compatible: should be "allwinner,sun4i-mdio".
+- reg: address and length of the register set for the device.
+
+Optional properties:
+- phy-supply: phandle to a regulator if the PHY needs one
+
+Example at the SoC level:
+mdio@01c0b080 {
+       compatible = "allwinner,sun4i-mdio";
+       reg = <0x01c0b080 0x14>;
+       #address-cells = <1>;
+       #size-cells = <0>;
+};
+
+And at the board level:
+
+mdio@01c0b080 {
+       phy-supply = <&reg_emac_3v3>;
+
+       phy0: ethernet-phy@0 {
+               reg = <0>;
+       };
+};

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 1e11f2b..3a316b3 100644 (file)
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -144,6 +144,16 @@ config MDIO_OCTEON
 
          If in doubt, say Y.
 
+config MDIO_SUN4I
+       tristate "Allwinner sun4i MDIO interface support"
+       depends on ARCH_SUNXI
+       select REGULATOR
+       select REGULATOR_FIXED_VOLTAGE
+       help
+         This driver supports the MDIO interface found in the network
+         interface units of the Allwinner SoC that have an EMAC (A10,
+         A12, A10s, etc.)
+
 config MDIO_BUS_MUX
        tristate
        depends on OF_MDIO

diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 9645e38..23a2ab2 100644 (file)
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -30,3 +30,4 @@ obj-$(CONFIG_AMD_PHY)         += amd.o
 obj-$(CONFIG_MDIO_BUS_MUX)     += mdio-mux.o
 obj-$(CONFIG_MDIO_BUS_MUX_GPIO)        += mdio-mux-gpio.o
 obj-$(CONFIG_MDIO_BUS_MUX_MMIOREG) += mdio-mux-mmioreg.o
+obj-$(CONFIG_MDIO_SUN4I)       += mdio-sun4i.o

diff --git a/drivers/net/phy/mdio-sun4i.c b/drivers/net/phy/mdio-sun4i.c
new file mode 100644 (file)
index 0000000..61d3f4e
--- /dev/null
+++ b/drivers/net/phy/mdio-sun4i.c
@@ -0,0 +1,194 @@
+/*
+ * Allwinner EMAC MDIO interface driver
+ *
+ * Copyright 2012-2013 Stefan Roese <sr@denx.de>
+ * Copyright 2013 Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * Based on the Linux driver provided by Allwinner:
+ * Copyright (C) 1997  Sten Wang
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_address.h>
+#include <linux/of_mdio.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+
+#define EMAC_MAC_MCMD_REG      (0x00)
+#define EMAC_MAC_MADR_REG      (0x04)
+#define EMAC_MAC_MWTD_REG      (0x08)
+#define EMAC_MAC_MRDD_REG      (0x0c)
+#define EMAC_MAC_MIND_REG      (0x10)
+#define EMAC_MAC_SSRR_REG      (0x14)
+
+#define MDIO_TIMEOUT           (msecs_to_jiffies(100))
+
+struct sun4i_mdio_data {
+       void __iomem            *membase;
+       struct regulator        *regulator;
+};
+
+static int sun4i_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
+{
+       struct sun4i_mdio_data *data = bus->priv;
+       unsigned long start_jiffies;
+       int value;
+
+       /* issue the phy address and reg */
+       writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
+       /* pull up the phy io line */
+       writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
+
+       /* Wait read complete */
+       start_jiffies = jiffies;
+       while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
+               if (time_after(start_jiffies,
+                              start_jiffies + MDIO_TIMEOUT))
+                       return -ETIMEDOUT;
+               msleep(1);
+       }
+
+       /* push down the phy io line */
+       writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
+       /* and read data */
+       value = readl(data->membase + EMAC_MAC_MRDD_REG);
+
+       return value;
+}
+
+static int sun4i_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
+                           u16 value)
+{
+       struct sun4i_mdio_data *data = bus->priv;
+       unsigned long start_jiffies;
+
+       /* issue the phy address and reg */
+       writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
+       /* pull up the phy io line */
+       writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
+
+       /* Wait read complete */
+       start_jiffies = jiffies;
+       while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
+               if (time_after(start_jiffies,
+                              start_jiffies + MDIO_TIMEOUT))
+                       return -ETIMEDOUT;
+               msleep(1);
+       }
+
+       /* push down the phy io line */
+       writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
+       /* and write data */
+       writel(value, data->membase + EMAC_MAC_MWTD_REG);
+
+       return 0;
+}
+
+static int sun4i_mdio_reset(struct mii_bus *bus)
+{
+       return 0;
+}
+
+static int sun4i_mdio_probe(struct platform_device *pdev)
+{
+       struct device_node *np = pdev->dev.of_node;
+       struct mii_bus *bus;
+       struct sun4i_mdio_data *data;
+       int ret, i;
+
+       bus = mdiobus_alloc_size(sizeof(*data));
+       if (!bus)
+               return -ENOMEM;
+
+       bus->name = "sun4i_mii_bus";
+       bus->read = &sun4i_mdio_read;
+       bus->write = &sun4i_mdio_write;
+       bus->reset = &sun4i_mdio_reset;
+       snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
+       bus->parent = &pdev->dev;
+
+       bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
+       if (!bus->irq) {
+               ret = -ENOMEM;
+               goto err_out_free_mdiobus;
+       }
+
+       for (i = 0; i < PHY_MAX_ADDR; i++)
+               bus->irq[i] = PHY_POLL;
+
+       data = bus->priv;
+       data->membase = of_iomap(np, 0);
+       if (!data->membase) {
+               ret = -ENOMEM;
+               goto err_out_free_mdio_irq;
+       }
+
+       data->regulator = devm_regulator_get(&pdev->dev, "phy");
+       if (IS_ERR(data->regulator)) {
+               if (PTR_ERR(data->regulator) == -EPROBE_DEFER)
+                       return -EPROBE_DEFER;
+
+               dev_info(&pdev->dev, "no regulator found\n");
+       } else {
+               ret = regulator_enable(data->regulator);
+               if (ret)
+                       goto err_out_free_mdio_irq;
+       }
+
+       ret = of_mdiobus_register(bus, np);
+       if (ret < 0)
+               goto err_out_disable_regulator;
+
+       platform_set_drvdata(pdev, bus);
+
+       return 0;
+
+err_out_disable_regulator:
+       regulator_disable(data->regulator);
+err_out_free_mdio_irq:
+       kfree(bus->irq);
+err_out_free_mdiobus:
+       mdiobus_free(bus);
+       return ret;
+}
+
+static int sun4i_mdio_remove(struct platform_device *pdev)
+{
+       struct mii_bus *bus = platform_get_drvdata(pdev);
+
+       mdiobus_unregister(bus);
+       kfree(bus->irq);
+       mdiobus_free(bus);
+
+       return 0;
+}
+
+static const struct of_device_id sun4i_mdio_dt_ids[] = {
+       { .compatible = "allwinner,sun4i-mdio" },
+       { }
+};
+MODULE_DEVICE_TABLE(of, sun4i_mdio_dt_ids);
+
+static struct platform_driver sun4i_mdio_driver = {
+       .probe = sun4i_mdio_probe,
+       .remove = sun4i_mdio_remove,
+       .driver = {
+               .name = "sun4i-mdio",
+               .of_match_table = sun4i_mdio_dt_ids,
+       },
+};
+
+module_platform_driver(sun4i_mdio_driver);
+
+MODULE_DESCRIPTION("Allwinner EMAC MDIO interface driver");
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
+MODULE_LICENSE("GPL");