1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2011, 2012 Cavium, Inc.
4 */
5
6 #include <linux/device.h>
7 #include <linux/gpio/consumer.h>
8 #include <linux/mdio-mux.h>
9 #include <linux/module.h>
10 #include <linux/of_mdio.h>
11 #include <linux/phy.h>
12 #include <linux/platform_device.h>
13
14 #define DRV_VERSION "1.1"
15 #define DRV_DESCRIPTION "GPIO controlled MDIO bus multiplexer driver"
16
17 struct mdio_mux_gpio_state {
18 struct gpio_descs *gpios;
19 void *mux_handle;
20 };
21
mdio_mux_gpio_switch_fn(int current_child,int desired_child,void * data)22 static int mdio_mux_gpio_switch_fn(int current_child, int desired_child,
23 void *data)
24 {
25 struct mdio_mux_gpio_state *s = data;
26 DECLARE_BITMAP(values, BITS_PER_TYPE(desired_child));
27
28 if (current_child == desired_child)
29 return 0;
30
31 values[0] = desired_child;
32
33 gpiod_set_array_value_cansleep(s->gpios->ndescs, s->gpios->desc,
34 s->gpios->info, values);
35
36 return 0;
37 }
38
mdio_mux_gpio_probe(struct platform_device * pdev)39 static int mdio_mux_gpio_probe(struct platform_device *pdev)
40 {
41 struct mdio_mux_gpio_state *s;
42 struct gpio_descs *gpios;
43 int r;
44
45 gpios = devm_gpiod_get_array(&pdev->dev, NULL, GPIOD_OUT_LOW);
46 if (IS_ERR(gpios))
47 return PTR_ERR(gpios);
48
49 s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
50 if (!s)
51 return -ENOMEM;
52
53 s->gpios = gpios;
54
55 r = mdio_mux_init(&pdev->dev, pdev->dev.of_node,
56 mdio_mux_gpio_switch_fn, &s->mux_handle, s, NULL);
57
58 if (r != 0)
59 return r;
60
61 pdev->dev.platform_data = s;
62 return 0;
63 }
64
mdio_mux_gpio_remove(struct platform_device * pdev)65 static int mdio_mux_gpio_remove(struct platform_device *pdev)
66 {
67 struct mdio_mux_gpio_state *s = dev_get_platdata(&pdev->dev);
68 mdio_mux_uninit(s->mux_handle);
69 return 0;
70 }
71
72 static const struct of_device_id mdio_mux_gpio_match[] = {
73 {
74 .compatible = "mdio-mux-gpio",
75 },
76 {
77 /* Legacy compatible property. */
78 .compatible = "cavium,mdio-mux-sn74cbtlv3253",
79 },
80 {},
81 };
82 MODULE_DEVICE_TABLE(of, mdio_mux_gpio_match);
83
84 static struct platform_driver mdio_mux_gpio_driver = {
85 .driver = {
86 .name = "mdio-mux-gpio",
87 .of_match_table = mdio_mux_gpio_match,
88 },
89 .probe = mdio_mux_gpio_probe,
90 .remove = mdio_mux_gpio_remove,
91 };
92
93 module_platform_driver(mdio_mux_gpio_driver);
94
95 MODULE_DESCRIPTION(DRV_DESCRIPTION);
96 MODULE_VERSION(DRV_VERSION);
97 MODULE_AUTHOR("David Daney");
98 MODULE_LICENSE("GPL v2");
99