projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 5fd54ace | 1 | // SPDX-License-Identifier: GPL-2.0+ |
| 740a6a17 SB |
2 | /* |
| 3 | * Driver for SMSC USB4604 USB HSIC 4-port 2.0 hub controller driver | |
| 4 | * Based on usb3503 driver | |
| 5 | * | |
| 6 | * Copyright (c) 2012-2013 Dongjin Kim (tobetter@gmail.com) | |
| 7 | * Copyright (c) 2016 Linaro Ltd. | |
| 740a6a17 SB |
8 | */ |
| 9 | ||
| 10 | #include <linux/i2c.h> | |
| 11 | #include <linux/delay.h> | |
| 12 | #include <linux/slab.h> | |
| 13 | #include <linux/module.h> | |
| 14 | #include <linux/gpio/consumer.h> | |
| 15 | ||
| 16 | enum usb4604_mode { | |
| 17 | USB4604_MODE_UNKNOWN, | |
| 18 | USB4604_MODE_HUB, | |
| 19 | USB4604_MODE_STANDBY, | |
| 20 | }; | |
| 21 | ||
| 22 | struct usb4604 { | |
| 23 | enum usb4604_mode mode; | |
| 24 | struct device *dev; | |
| 25 | struct gpio_desc *gpio_reset; | |
| 26 | }; | |
| 27 | ||
| 28 | static void usb4604_reset(struct usb4604 *hub, int state) | |
| 29 | { | |
| 30 | gpiod_set_value_cansleep(hub->gpio_reset, state); | |
| 31 | ||
| 32 | /* Wait for i2c logic to come up */ | |
| 33 | if (state) | |
| 34 | msleep(250); | |
| 35 | } | |
| 36 | ||
| 37 | static int usb4604_connect(struct usb4604 *hub) | |
| 38 | { | |
| 39 | struct device *dev = hub->dev; | |
| 40 | struct i2c_client *client = to_i2c_client(dev); | |
| 41 | int err; | |
| 42 | u8 connect_cmd[] = { 0xaa, 0x55, 0x00 }; | |
| 43 | ||
| 44 | usb4604_reset(hub, 1); | |
| 45 | ||
| 46 | err = i2c_master_send(client, connect_cmd, ARRAY_SIZE(connect_cmd)); | |
| 47 | if (err < 0) { | |
| 48 | usb4604_reset(hub, 0); | |
| 49 | return err; | |
| 50 | } | |
| 51 | ||
| 52 | hub->mode = USB4604_MODE_HUB; | |
| 53 | dev_dbg(dev, "switched to HUB mode\n"); | |
| 54 | ||
| 55 | return 0; | |
| 56 | } | |
| 57 | ||
| 58 | static int usb4604_switch_mode(struct usb4604 *hub, enum usb4604_mode mode) | |
| 59 | { | |
| 60 | struct device *dev = hub->dev; | |
| 61 | int err = 0; | |
| 62 | ||
| 63 | switch (mode) { | |
| 64 | case USB4604_MODE_HUB: | |
| 65 | err = usb4604_connect(hub); | |
| 66 | break; | |
| 67 | ||
| 68 | case USB4604_MODE_STANDBY: | |
| 69 | usb4604_reset(hub, 0); | |
| 70 | dev_dbg(dev, "switched to STANDBY mode\n"); | |
| 71 | break; | |
| 72 | ||
| 73 | default: | |
| 74 | dev_err(dev, "unknown mode is requested\n"); | |
| 75 | err = -EINVAL; | |
| 76 | break; | |
| 77 | } | |
| 78 | ||
| 79 | return err; | |
| 80 | } | |
| 81 | ||
| 82 | static int usb4604_probe(struct usb4604 *hub) | |
| 83 | { | |
| 84 | struct device *dev = hub->dev; | |
| 85 | struct device_node *np = dev->of_node; | |
| 86 | struct gpio_desc *gpio; | |
| 87 | u32 mode = USB4604_MODE_HUB; | |
| 88 | ||
| 89 | gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); | |
| 90 | if (IS_ERR(gpio)) | |
| 91 | return PTR_ERR(gpio); | |
| 92 | hub->gpio_reset = gpio; | |
| 93 | ||
| 94 | if (of_property_read_u32(np, "initial-mode", &hub->mode)) | |
| 95 | hub->mode = mode; | |
| 96 | ||
| 97 | return usb4604_switch_mode(hub, hub->mode); | |
| 98 | } | |
| 99 | ||
| 100 | static int usb4604_i2c_probe(struct i2c_client *i2c, | |
| 101 | const struct i2c_device_id *id) | |
| 102 | { | |
| 103 | struct usb4604 *hub; | |
| 104 | ||
| 105 | hub = devm_kzalloc(&i2c->dev, sizeof(*hub), GFP_KERNEL); | |
| 106 | if (!hub) | |
| 107 | return -ENOMEM; | |
| 108 | ||
| 109 | i2c_set_clientdata(i2c, hub); | |
| 110 | hub->dev = &i2c->dev; | |
| 111 | ||
| 112 | return usb4604_probe(hub); | |
| 113 | } | |
| 114 | ||
| 115 | #ifdef CONFIG_PM_SLEEP | |
| 116 | static int usb4604_i2c_suspend(struct device *dev) | |
| 117 | { | |
| 118 | struct i2c_client *client = to_i2c_client(dev); | |
| 119 | struct usb4604 *hub = i2c_get_clientdata(client); | |
| 120 | ||
| 121 | usb4604_switch_mode(hub, USB4604_MODE_STANDBY); | |
| 122 | ||
| 123 | return 0; | |
| 124 | } | |
| 125 | ||
| 126 | static int usb4604_i2c_resume(struct device *dev) | |
| 127 | { | |
| 128 | struct i2c_client *client = to_i2c_client(dev); | |
| 129 | struct usb4604 *hub = i2c_get_clientdata(client); | |
| 130 | ||
| 131 | usb4604_switch_mode(hub, hub->mode); | |
| 132 | ||
| 133 | return 0; | |
| 134 | } | |
| 135 | #endif | |
| 136 | ||
| 137 | static SIMPLE_DEV_PM_OPS(usb4604_i2c_pm_ops, usb4604_i2c_suspend, | |
| 138 | usb4604_i2c_resume); | |
| 139 | ||
| 140 | static const struct i2c_device_id usb4604_id[] = { | |
| 141 | { "usb4604", 0 }, | |
| 142 | { } | |
| 143 | }; | |
| 144 | MODULE_DEVICE_TABLE(i2c, usb4604_id); | |
| 145 | ||
| 146 | #ifdef CONFIG_OF | |
| 147 | static const struct of_device_id usb4604_of_match[] = { | |
| 148 | { .compatible = "smsc,usb4604" }, | |
| 149 | {} | |
| 150 | }; | |
| 151 | MODULE_DEVICE_TABLE(of, usb4604_of_match); | |
| 152 | #endif | |
| 153 | ||
| 154 | static struct i2c_driver usb4604_i2c_driver = { | |
| 155 | .driver = { | |
| 156 | .name = "usb4604", | |
| 157 | .pm = &usb4604_i2c_pm_ops, | |
| 158 | .of_match_table = of_match_ptr(usb4604_of_match), | |
| 159 | }, | |
| 160 | .probe = usb4604_i2c_probe, | |
| 161 | .id_table = usb4604_id, | |
| 162 | }; | |
| 163 | module_i2c_driver(usb4604_i2c_driver); | |
| 164 | ||
| 165 | MODULE_DESCRIPTION("USB4604 USB HUB driver"); | |
| 166 | MODULE_LICENSE("GPL v2"); |