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/init.h>
14 #include <linux/phy.h>
15 #include <linux/mdio-mux.h>
16 #include <linux/of_gpio.h>
18 #define DRV_VERSION "1.0"
19 #define DRV_DESCRIPTION "GPIO controlled MDIO bus multiplexer driver"
21 #define MDIO_MUX_GPIO_MAX_BITS 8
23 struct mdio_mux_gpio_state
{
24 int gpio
[MDIO_MUX_GPIO_MAX_BITS
];
25 unsigned int num_gpios
;
29 static int mdio_mux_gpio_switch_fn(int current_child
, int desired_child
,
34 struct mdio_mux_gpio_state
*s
= data
;
36 if (current_child
== desired_child
)
39 change
= current_child
== -1 ? -1 : current_child
^ desired_child
;
41 for (n
= 0; n
< s
->num_gpios
; n
++) {
43 gpio_set_value_cansleep(s
->gpio
[n
],
44 (desired_child
& 1) != 0);
52 static int mdio_mux_gpio_probe(struct platform_device
*pdev
)
55 struct mdio_mux_gpio_state
*s
;
60 if (!pdev
->dev
.of_node
)
63 num_gpios
= of_gpio_count(pdev
->dev
.of_node
);
64 if (num_gpios
<= 0 || num_gpios
> MDIO_MUX_GPIO_MAX_BITS
)
67 s
= devm_kzalloc(&pdev
->dev
, sizeof(*s
), GFP_KERNEL
);
71 s
->num_gpios
= num_gpios
;
73 for (n
= 0; n
< num_gpios
; ) {
74 int gpio
= of_get_gpio_flags(pdev
->dev
.of_node
, n
, &f
);
76 r
= (gpio
== -ENODEV
) ? -EPROBE_DEFER
: gpio
;
83 r
= gpio_request(gpio
, "mdio_mux_gpio");
87 r
= gpio_direction_output(gpio
, 0);
92 r
= mdio_mux_init(&pdev
->dev
,
93 mdio_mux_gpio_switch_fn
, &s
->mux_handle
, s
);
96 pdev
->dev
.platform_data
= s
;
102 gpio_free(s
->gpio
[n
]);
107 static int mdio_mux_gpio_remove(struct platform_device
*pdev
)
109 struct mdio_mux_gpio_state
*s
= dev_get_platdata(&pdev
->dev
);
110 mdio_mux_uninit(s
->mux_handle
);
114 static struct of_device_id mdio_mux_gpio_match
[] = {
116 .compatible
= "mdio-mux-gpio",
119 /* Legacy compatible property. */
120 .compatible
= "cavium,mdio-mux-sn74cbtlv3253",
124 MODULE_DEVICE_TABLE(of
, mdio_mux_gpio_match
);
126 static struct platform_driver mdio_mux_gpio_driver
= {
128 .name
= "mdio-mux-gpio",
129 .owner
= THIS_MODULE
,
130 .of_match_table
= mdio_mux_gpio_match
,
132 .probe
= mdio_mux_gpio_probe
,
133 .remove
= mdio_mux_gpio_remove
,
136 module_platform_driver(mdio_mux_gpio_driver
);
138 MODULE_DESCRIPTION(DRV_DESCRIPTION
);
139 MODULE_VERSION(DRV_VERSION
);
140 MODULE_AUTHOR("David Daney");
141 MODULE_LICENSE("GPL");