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13#include <linux/kernel.h>
14#include <linux/tty.h>
15#include <linux/slab.h>
16#include <linux/tty_driver.h>
17#include <linux/tty_flip.h>
18#include <linux/module.h>
19#include <linux/usb.h>
20#include <linux/usb/serial.h>
21#include <linux/uaccess.h>
22
23static const struct usb_device_id id_table[] = {
24 { USB_DEVICE(0x05e0, 0x0600) },
25 { },
26};
27MODULE_DEVICE_TABLE(usb, id_table);
28
29struct symbol_private {
30 spinlock_t lock;
31 bool throttled;
32 bool actually_throttled;
33};
34
35static void symbol_int_callback(struct urb *urb)
36{
37 struct usb_serial_port *port = urb->context;
38 struct symbol_private *priv = usb_get_serial_port_data(port);
39 unsigned char *data = urb->transfer_buffer;
40 int status = urb->status;
41 int result;
42 int data_length;
43
44 switch (status) {
45 case 0:
46
47 break;
48 case -ECONNRESET:
49 case -ENOENT:
50 case -ESHUTDOWN:
51
52 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
53 __func__, status);
54 return;
55 default:
56 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
57 __func__, status);
58 goto exit;
59 }
60
61 usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
62
63
64
65
66
67
68 if (urb->actual_length > 1) {
69 data_length = data[0];
70 if (data_length > (urb->actual_length - 1))
71 data_length = urb->actual_length - 1;
72 tty_insert_flip_string(&port->port, &data[1], data_length);
73 tty_flip_buffer_push(&port->port);
74 } else {
75 dev_dbg(&port->dev, "%s - short packet\n", __func__);
76 }
77
78exit:
79 spin_lock(&priv->lock);
80
81
82 if (!priv->throttled) {
83 result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
84 if (result)
85 dev_err(&port->dev,
86 "%s - failed resubmitting read urb, error %d\n",
87 __func__, result);
88 } else
89 priv->actually_throttled = true;
90 spin_unlock(&priv->lock);
91}
92
93static int symbol_open(struct tty_struct *tty, struct usb_serial_port *port)
94{
95 struct symbol_private *priv = usb_get_serial_port_data(port);
96 unsigned long flags;
97 int result = 0;
98
99 spin_lock_irqsave(&priv->lock, flags);
100 priv->throttled = false;
101 priv->actually_throttled = false;
102 spin_unlock_irqrestore(&priv->lock, flags);
103
104
105 result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
106 if (result)
107 dev_err(&port->dev,
108 "%s - failed resubmitting read urb, error %d\n",
109 __func__, result);
110 return result;
111}
112
113static void symbol_close(struct usb_serial_port *port)
114{
115 usb_kill_urb(port->interrupt_in_urb);
116}
117
118static void symbol_throttle(struct tty_struct *tty)
119{
120 struct usb_serial_port *port = tty->driver_data;
121 struct symbol_private *priv = usb_get_serial_port_data(port);
122
123 spin_lock_irq(&priv->lock);
124 priv->throttled = true;
125 spin_unlock_irq(&priv->lock);
126}
127
128static void symbol_unthrottle(struct tty_struct *tty)
129{
130 struct usb_serial_port *port = tty->driver_data;
131 struct symbol_private *priv = usb_get_serial_port_data(port);
132 int result;
133 bool was_throttled;
134
135 spin_lock_irq(&priv->lock);
136 priv->throttled = false;
137 was_throttled = priv->actually_throttled;
138 priv->actually_throttled = false;
139 spin_unlock_irq(&priv->lock);
140
141 if (was_throttled) {
142 result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
143 if (result)
144 dev_err(&port->dev,
145 "%s - failed submitting read urb, error %d\n",
146 __func__, result);
147 }
148}
149
150static int symbol_startup(struct usb_serial *serial)
151{
152 if (!serial->num_interrupt_in) {
153 dev_err(&serial->dev->dev, "no interrupt-in endpoint\n");
154 return -ENODEV;
155 }
156
157 return 0;
158}
159
160static int symbol_port_probe(struct usb_serial_port *port)
161{
162 struct symbol_private *priv;
163
164 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
165 if (!priv)
166 return -ENOMEM;
167
168 spin_lock_init(&priv->lock);
169
170 usb_set_serial_port_data(port, priv);
171
172 return 0;
173}
174
175static int symbol_port_remove(struct usb_serial_port *port)
176{
177 struct symbol_private *priv = usb_get_serial_port_data(port);
178
179 kfree(priv);
180
181 return 0;
182}
183
184static struct usb_serial_driver symbol_device = {
185 .driver = {
186 .owner = THIS_MODULE,
187 .name = "symbol",
188 },
189 .id_table = id_table,
190 .num_ports = 1,
191 .attach = symbol_startup,
192 .port_probe = symbol_port_probe,
193 .port_remove = symbol_port_remove,
194 .open = symbol_open,
195 .close = symbol_close,
196 .throttle = symbol_throttle,
197 .unthrottle = symbol_unthrottle,
198 .read_int_callback = symbol_int_callback,
199};
200
201static struct usb_serial_driver * const serial_drivers[] = {
202 &symbol_device, NULL
203};
204
205module_usb_serial_driver(serial_drivers, id_table);
206
207MODULE_LICENSE("GPL");
208
