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 };
24
mdio_mux_gpio_switch_fn(int current_child,int desired_child,void * data)25 static int mdio_mux_gpio_switch_fn(int current_child, int desired_child,
26 void *data)
27 {
28 struct mdio_mux_gpio_state *s = data;
29 int values[s->gpios->ndescs];
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 values[n] = (desired_child >> n) & 1;
37
38 gpiod_set_array_value_cansleep(s->gpios->ndescs, s->gpios->desc,
39 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 int r;
48
49 s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
50 if (!s)
51 return -ENOMEM;
52
53 s->gpios = gpiod_get_array(&pdev->dev, NULL, GPIOD_OUT_LOW);
54 if (IS_ERR(s->gpios))
55 return PTR_ERR(s->gpios);
56
57 r = mdio_mux_init(&pdev->dev,
58 mdio_mux_gpio_switch_fn, &s->mux_handle, s, NULL);
59
60 if (r != 0) {
61 gpiod_put_array(s->gpios);
62 return r;
63 }
64
65 pdev->dev.platform_data = s;
66 return 0;
67 }
68
mdio_mux_gpio_remove(struct platform_device * pdev)69 static int mdio_mux_gpio_remove(struct platform_device *pdev)
70 {
71 struct mdio_mux_gpio_state *s = dev_get_platdata(&pdev->dev);
72 mdio_mux_uninit(s->mux_handle);
73 gpiod_put_array(s->gpios);
74 return 0;
75 }
76
77 static const struct of_device_id mdio_mux_gpio_match[] = {
78 {
79 .compatible = "mdio-mux-gpio",
80 },
81 {
82 /* Legacy compatible property. */
83 .compatible = "cavium,mdio-mux-sn74cbtlv3253",
84 },
85 {},
86 };
87 MODULE_DEVICE_TABLE(of, mdio_mux_gpio_match);
88
89 static struct platform_driver mdio_mux_gpio_driver = {
90 .driver = {
91 .name = "mdio-mux-gpio",
92 .of_match_table = mdio_mux_gpio_match,
93 },
94 .probe = mdio_mux_gpio_probe,
95 .remove = mdio_mux_gpio_remove,
96 };
97
98 module_platform_driver(mdio_mux_gpio_driver);
99
100 MODULE_DESCRIPTION(DRV_DESCRIPTION);
101 MODULE_VERSION(DRV_VERSION);
102 MODULE_AUTHOR("David Daney");
103 MODULE_LICENSE("GPL");
104