Commit | Line | Data |
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740a6a17 SB |
1 | /* |
2 | * Driver for SMSC USB4604 USB HSIC 4-port 2.0 hub controller driver | |
3 | * Based on usb3503 driver | |
4 | * | |
5 | * Copyright (c) 2012-2013 Dongjin Kim (tobetter@gmail.com) | |
6 | * Copyright (c) 2016 Linaro Ltd. | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2 of the License, or | |
11 | * (at your option) any later version. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | */ | |
18 | ||
19 | #include <linux/i2c.h> | |
20 | #include <linux/delay.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/gpio/consumer.h> | |
24 | ||
25 | enum usb4604_mode { | |
26 | USB4604_MODE_UNKNOWN, | |
27 | USB4604_MODE_HUB, | |
28 | USB4604_MODE_STANDBY, | |
29 | }; | |
30 | ||
31 | struct usb4604 { | |
32 | enum usb4604_mode mode; | |
33 | struct device *dev; | |
34 | struct gpio_desc *gpio_reset; | |
35 | }; | |
36 | ||
37 | static void usb4604_reset(struct usb4604 *hub, int state) | |
38 | { | |
39 | gpiod_set_value_cansleep(hub->gpio_reset, state); | |
40 | ||
41 | /* Wait for i2c logic to come up */ | |
42 | if (state) | |
43 | msleep(250); | |
44 | } | |
45 | ||
46 | static int usb4604_connect(struct usb4604 *hub) | |
47 | { | |
48 | struct device *dev = hub->dev; | |
49 | struct i2c_client *client = to_i2c_client(dev); | |
50 | int err; | |
51 | u8 connect_cmd[] = { 0xaa, 0x55, 0x00 }; | |
52 | ||
53 | usb4604_reset(hub, 1); | |
54 | ||
55 | err = i2c_master_send(client, connect_cmd, ARRAY_SIZE(connect_cmd)); | |
56 | if (err < 0) { | |
57 | usb4604_reset(hub, 0); | |
58 | return err; | |
59 | } | |
60 | ||
61 | hub->mode = USB4604_MODE_HUB; | |
62 | dev_dbg(dev, "switched to HUB mode\n"); | |
63 | ||
64 | return 0; | |
65 | } | |
66 | ||
67 | static int usb4604_switch_mode(struct usb4604 *hub, enum usb4604_mode mode) | |
68 | { | |
69 | struct device *dev = hub->dev; | |
70 | int err = 0; | |
71 | ||
72 | switch (mode) { | |
73 | case USB4604_MODE_HUB: | |
74 | err = usb4604_connect(hub); | |
75 | break; | |
76 | ||
77 | case USB4604_MODE_STANDBY: | |
78 | usb4604_reset(hub, 0); | |
79 | dev_dbg(dev, "switched to STANDBY mode\n"); | |
80 | break; | |
81 | ||
82 | default: | |
83 | dev_err(dev, "unknown mode is requested\n"); | |
84 | err = -EINVAL; | |
85 | break; | |
86 | } | |
87 | ||
88 | return err; | |
89 | } | |
90 | ||
91 | static int usb4604_probe(struct usb4604 *hub) | |
92 | { | |
93 | struct device *dev = hub->dev; | |
94 | struct device_node *np = dev->of_node; | |
95 | struct gpio_desc *gpio; | |
96 | u32 mode = USB4604_MODE_HUB; | |
97 | ||
98 | gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); | |
99 | if (IS_ERR(gpio)) | |
100 | return PTR_ERR(gpio); | |
101 | hub->gpio_reset = gpio; | |
102 | ||
103 | if (of_property_read_u32(np, "initial-mode", &hub->mode)) | |
104 | hub->mode = mode; | |
105 | ||
106 | return usb4604_switch_mode(hub, hub->mode); | |
107 | } | |
108 | ||
109 | static int usb4604_i2c_probe(struct i2c_client *i2c, | |
110 | const struct i2c_device_id *id) | |
111 | { | |
112 | struct usb4604 *hub; | |
113 | ||
114 | hub = devm_kzalloc(&i2c->dev, sizeof(*hub), GFP_KERNEL); | |
115 | if (!hub) | |
116 | return -ENOMEM; | |
117 | ||
118 | i2c_set_clientdata(i2c, hub); | |
119 | hub->dev = &i2c->dev; | |
120 | ||
121 | return usb4604_probe(hub); | |
122 | } | |
123 | ||
124 | #ifdef CONFIG_PM_SLEEP | |
125 | static int usb4604_i2c_suspend(struct device *dev) | |
126 | { | |
127 | struct i2c_client *client = to_i2c_client(dev); | |
128 | struct usb4604 *hub = i2c_get_clientdata(client); | |
129 | ||
130 | usb4604_switch_mode(hub, USB4604_MODE_STANDBY); | |
131 | ||
132 | return 0; | |
133 | } | |
134 | ||
135 | static int usb4604_i2c_resume(struct device *dev) | |
136 | { | |
137 | struct i2c_client *client = to_i2c_client(dev); | |
138 | struct usb4604 *hub = i2c_get_clientdata(client); | |
139 | ||
140 | usb4604_switch_mode(hub, hub->mode); | |
141 | ||
142 | return 0; | |
143 | } | |
144 | #endif | |
145 | ||
146 | static SIMPLE_DEV_PM_OPS(usb4604_i2c_pm_ops, usb4604_i2c_suspend, | |
147 | usb4604_i2c_resume); | |
148 | ||
149 | static const struct i2c_device_id usb4604_id[] = { | |
150 | { "usb4604", 0 }, | |
151 | { } | |
152 | }; | |
153 | MODULE_DEVICE_TABLE(i2c, usb4604_id); | |
154 | ||
155 | #ifdef CONFIG_OF | |
156 | static const struct of_device_id usb4604_of_match[] = { | |
157 | { .compatible = "smsc,usb4604" }, | |
158 | {} | |
159 | }; | |
160 | MODULE_DEVICE_TABLE(of, usb4604_of_match); | |
161 | #endif | |
162 | ||
163 | static struct i2c_driver usb4604_i2c_driver = { | |
164 | .driver = { | |
165 | .name = "usb4604", | |
166 | .pm = &usb4604_i2c_pm_ops, | |
167 | .of_match_table = of_match_ptr(usb4604_of_match), | |
168 | }, | |
169 | .probe = usb4604_i2c_probe, | |
170 | .id_table = usb4604_id, | |
171 | }; | |
172 | module_i2c_driver(usb4604_i2c_driver); | |
173 | ||
174 | MODULE_DESCRIPTION("USB4604 USB HUB driver"); | |
175 | MODULE_LICENSE("GPL v2"); |