1 files changed, 142 insertions, 0 deletions
diff --git a/drivers/net/phy/mdio-mux-gpio.c b/drivers/net/phy/mdio-mux-gpio.c
new file mode 100644
index 000000000000..e0cc4ef33dee
--- /dev/null
+++ b/drivers/net/phy/mdio-mux-gpio.c
@@ -0,0 +1,142 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2011, 2012 Cavium, Inc.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/device.h>
+#include <linux/of_mdio.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/phy.h>
+#include <linux/mdio-mux.h>
+#include <linux/of_gpio.h>
+
+#define DRV_VERSION "1.0"
+#define DRV_DESCRIPTION "GPIO controlled MDIO bus multiplexer driver"
+
+#define MDIO_MUX_GPIO_MAX_BITS 8
+
+struct mdio_mux_gpio_state {
+	int gpio[MDIO_MUX_GPIO_MAX_BITS];
+	unsigned int num_gpios;
+	void *mux_handle;
+};
+
+static int mdio_mux_gpio_switch_fn(int current_child, int desired_child,
+				   void *data)
+{
+	int change;
+	unsigned int n;
+	struct mdio_mux_gpio_state *s = data;
+
+	if (current_child == desired_child)
+		return 0;
+
+	change = current_child == -1 ? -1 : current_child ^ desired_child;
+
+	for (n = 0; n < s->num_gpios; n++) {
+		if (change & 1)
+			gpio_set_value_cansleep(s->gpio[n],
+						(desired_child & 1) != 0);
+		change >>= 1;
+		desired_child >>= 1;
+	}
+
+	return 0;
+}
+
+static int __devinit mdio_mux_gpio_probe(struct platform_device *pdev)
+{
+	enum of_gpio_flags f;
+	struct mdio_mux_gpio_state *s;
+	unsigned int num_gpios;
+	unsigned int n;
+	int r;
+
+	if (!pdev->dev.of_node)
+		return -ENODEV;
+
+	num_gpios = of_gpio_count(pdev->dev.of_node);
+	if (num_gpios == 0 || num_gpios > MDIO_MUX_GPIO_MAX_BITS)
+		return -ENODEV;
+
+	s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
+	if (!s)
+		return -ENOMEM;
+
+	s->num_gpios = num_gpios;
+
+	for (n = 0; n < num_gpios; ) {
+		int gpio = of_get_gpio_flags(pdev->dev.of_node, n, &f);
+		if (gpio < 0) {
+			r = (gpio == -ENODEV) ? -EPROBE_DEFER : gpio;
+			goto err;
+		}
+		s->gpio[n] = gpio;
+
+		n++;
+
+		r = gpio_request(gpio, "mdio_mux_gpio");
+		if (r)
+			goto err;
+
+		r = gpio_direction_output(gpio, 0);
+		if (r)
+			goto err;
+	}
+
+	r = mdio_mux_init(&pdev->dev,
+			  mdio_mux_gpio_switch_fn, &s->mux_handle, s);
+
+	if (r == 0) {
+		pdev->dev.platform_data = s;
+		return 0;
+	}
+err:
+	while (n) {
+		n--;
+		gpio_free(s->gpio[n]);
+	}
+	devm_kfree(&pdev->dev, s);
+	return r;
+}
+
+static int __devexit mdio_mux_gpio_remove(struct platform_device *pdev)
+{
+	struct mdio_mux_gpio_state *s = pdev->dev.platform_data;
+	mdio_mux_uninit(s->mux_handle);
+	return 0;
+}
+
+static struct of_device_id mdio_mux_gpio_match[] = {
+	{
+		.compatible = "mdio-mux-gpio",
+	},
+	{
+		/* Legacy compatible property. */
+		.compatible = "cavium,mdio-mux-sn74cbtlv3253",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, mdio_mux_gpio_match);
+
+static struct platform_driver mdio_mux_gpio_driver = {
+	.driver = {
+		.name		= "mdio-mux-gpio",
+		.owner		= THIS_MODULE,
+		.of_match_table = mdio_mux_gpio_match,
+	},
+	.probe		= mdio_mux_gpio_probe,
+	.remove		= __devexit_p(mdio_mux_gpio_remove),
+};
+
+module_platform_driver(mdio_mux_gpio_driver);
+
+MODULE_DESCRIPTION(DRV_DESCRIPTION);
+MODULE_VERSION(DRV_VERSION);
+MODULE_AUTHOR("David Daney");
+MODULE_LICENSE("GPL");