2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 2011, 2012 Cavium, Inc.
9 #include <linux/platform_device.h>
10 #include <linux/device.h>
11 #include <linux/of_mdio.h>
12 #include <linux/module.h>
13 #include <linux/phy.h>
14 #include <linux/mdio-mux.h>
15 #include <linux/of_gpio.h>
17 #define DRV_VERSION "1.0"
18 #define DRV_DESCRIPTION "GPIO controlled MDIO bus multiplexer driver"
20 #define MDIO_MUX_GPIO_MAX_BITS 8
22 struct mdio_mux_gpio_state {
23 int gpio[MDIO_MUX_GPIO_MAX_BITS];
24 unsigned int num_gpios;
28 static int mdio_mux_gpio_switch_fn(int current_child, int desired_child,
33 struct mdio_mux_gpio_state *s = data;
35 if (current_child == desired_child)
38 change = current_child == -1 ? -1 : current_child ^ desired_child;
40 for (n = 0; n < s->num_gpios; n++) {
42 gpio_set_value_cansleep(s->gpio[n],
43 (desired_child & 1) != 0);
51 static int mdio_mux_gpio_probe(struct platform_device *pdev)
54 struct mdio_mux_gpio_state *s;
59 if (!pdev->dev.of_node)
62 num_gpios = of_gpio_count(pdev->dev.of_node);
63 if (num_gpios <= 0 || num_gpios > MDIO_MUX_GPIO_MAX_BITS)
66 s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
70 s->num_gpios = num_gpios;
72 for (n = 0; n < num_gpios; ) {
73 int gpio = of_get_gpio_flags(pdev->dev.of_node, n, &f);
75 r = (gpio == -ENODEV) ? -EPROBE_DEFER : gpio;
82 r = gpio_request(gpio, "mdio_mux_gpio");
86 r = gpio_direction_output(gpio, 0);
91 r = mdio_mux_init(&pdev->dev,
92 mdio_mux_gpio_switch_fn, &s->mux_handle, s);
95 pdev->dev.platform_data = s;
101 gpio_free(s->gpio[n]);
106 static int mdio_mux_gpio_remove(struct platform_device *pdev)
108 struct mdio_mux_gpio_state *s = dev_get_platdata(&pdev->dev);
109 mdio_mux_uninit(s->mux_handle);
113 static struct of_device_id mdio_mux_gpio_match[] = {
115 .compatible = "mdio-mux-gpio",
118 /* Legacy compatible property. */
119 .compatible = "cavium,mdio-mux-sn74cbtlv3253",
123 MODULE_DEVICE_TABLE(of, mdio_mux_gpio_match);
125 static struct platform_driver mdio_mux_gpio_driver = {
127 .name = "mdio-mux-gpio",
128 .owner = THIS_MODULE,
129 .of_match_table = mdio_mux_gpio_match,
131 .probe = mdio_mux_gpio_probe,
132 .remove = mdio_mux_gpio_remove,
135 module_platform_driver(mdio_mux_gpio_driver);
137 MODULE_DESCRIPTION(DRV_DESCRIPTION);
138 MODULE_VERSION(DRV_VERSION);
139 MODULE_AUTHOR("David Daney");
140 MODULE_LICENSE("GPL");