1 /*
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
4 * for more details.
5 *
6 * Copyright (C) 2011, 2012 Cavium, Inc.
7 */
8
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/gpio/consumer.h>
16
17 #define DRV_VERSION "1.1"
18 #define DRV_DESCRIPTION "GPIO controlled MDIO bus multiplexer driver"
19
20 struct mdio_mux_gpio_state {
21 struct gpio_descs *gpios;
22 void *mux_handle;
23 int values[];
24 };
25
mdio_mux_gpio_switch_fn(int current_child,int desired_child,void * data)26 static int mdio_mux_gpio_switch_fn(int current_child, int desired_child,
27 void *data)
28 {
29 struct mdio_mux_gpio_state *s = data;
30 unsigned int n;
31
32 if (current_child == desired_child)
33 return 0;
34
35 for (n = 0; n < s->gpios->ndescs; n++)
36 s->values[n] = (desired_child >> n) & 1;
37
38 gpiod_set_array_value_cansleep(s->gpios->ndescs, s->gpios->desc,
39 s->values);
40
41 return 0;
42 }
43
mdio_mux_gpio_probe(struct platform_device * pdev)44 static int mdio_mux_gpio_probe(struct platform_device *pdev)
45 {
46 struct mdio_mux_gpio_state *s;
47 struct gpio_descs *gpios;
48 int r;
49
50 gpios = gpiod_get_array(&pdev->dev, NULL, GPIOD_OUT_LOW);
51 if (IS_ERR(gpios))
52 return PTR_ERR(gpios);
53
54 s = devm_kzalloc(&pdev->dev, struct_size(s, values, gpios->ndescs),
55 GFP_KERNEL);
56 if (!s) {
57 gpiod_put_array(gpios);
58 return -ENOMEM;
59 }
60
61 s->gpios = gpios;
62
63 r = mdio_mux_init(&pdev->dev, pdev->dev.of_node,
64 mdio_mux_gpio_switch_fn, &s->mux_handle, s, NULL);
65
66 if (r != 0) {
67 gpiod_put_array(s->gpios);
68 return r;
69 }
70
71 pdev->dev.platform_data = s;
72 return 0;
73 }
74
mdio_mux_gpio_remove(struct platform_device * pdev)75 static int mdio_mux_gpio_remove(struct platform_device *pdev)
76 {
77 struct mdio_mux_gpio_state *s = dev_get_platdata(&pdev->dev);
78 mdio_mux_uninit(s->mux_handle);
79 gpiod_put_array(s->gpios);
80 return 0;
81 }
82
83 static const struct of_device_id mdio_mux_gpio_match[] = {
84 {
85 .compatible = "mdio-mux-gpio",
86 },
87 {
88 /* Legacy compatible property. */
89 .compatible = "cavium,mdio-mux-sn74cbtlv3253",
90 },
91 {},
92 };
93 MODULE_DEVICE_TABLE(of, mdio_mux_gpio_match);
94
95 static struct platform_driver mdio_mux_gpio_driver = {
96 .driver = {
97 .name = "mdio-mux-gpio",
98 .of_match_table = mdio_mux_gpio_match,
99 },
100 .probe = mdio_mux_gpio_probe,
101 .remove = mdio_mux_gpio_remove,
102 };
103
104 module_platform_driver(mdio_mux_gpio_driver);
105
106 MODULE_DESCRIPTION(DRV_DESCRIPTION);
107 MODULE_VERSION(DRV_VERSION);
108 MODULE_AUTHOR("David Daney");
109 MODULE_LICENSE("GPL");
110
