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");