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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 if (urb->actual_length > 1) {
64 data_length = urb->actual_length - 1;
65
66
67
68
69
70
71
72
73
74 tty_insert_flip_string(&port->port, &data[1], data_length);
75 tty_flip_buffer_push(&port->port);
76 } else {
77 dev_dbg(&port->dev, "%s - short packet\n", __func__);
78 }
79
80exit:
81 spin_lock(&priv->lock);
82
83
84 if (!priv->throttled) {
85 result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
86 if (result)
87 dev_err(&port->dev,
88 "%s - failed resubmitting read urb, error %d\n",
89 __func__, result);
90 } else
91 priv->actually_throttled = true;
92 spin_unlock(&priv->lock);
93}
94
95static int symbol_open(struct tty_struct *tty, struct usb_serial_port *port)
96{
97 struct symbol_private *priv = usb_get_serial_data(port->serial);
98 unsigned long flags;
99 int result = 0;
100
101 spin_lock_irqsave(&priv->lock, flags);
102 priv->throttled = false;
103 priv->actually_throttled = false;
104 spin_unlock_irqrestore(&priv->lock, flags);
105
106
107 result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
108 if (result)
109 dev_err(&port->dev,
110 "%s - failed resubmitting read urb, error %d\n",
111 __func__, result);
112 return result;
113}
114
115static void symbol_close(struct usb_serial_port *port)
116{
117 usb_kill_urb(port->interrupt_in_urb);
118}
119
120static void symbol_throttle(struct tty_struct *tty)
121{
122 struct usb_serial_port *port = tty->driver_data;
123 struct symbol_private *priv = usb_get_serial_data(port->serial);
124
125 spin_lock_irq(&priv->lock);
126 priv->throttled = true;
127 spin_unlock_irq(&priv->lock);
128}
129
130static void symbol_unthrottle(struct tty_struct *tty)
131{
132 struct usb_serial_port *port = tty->driver_data;
133 struct symbol_private *priv = usb_get_serial_data(port->serial);
134 int result;
135 bool was_throttled;
136
137 spin_lock_irq(&priv->lock);
138 priv->throttled = false;
139 was_throttled = priv->actually_throttled;
140 priv->actually_throttled = false;
141 spin_unlock_irq(&priv->lock);
142
143 if (was_throttled) {
144 result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
145 if (result)
146 dev_err(&port->dev,
147 "%s - failed submitting read urb, error %d\n",
148 __func__, result);
149 }
150}
151
152static int symbol_startup(struct usb_serial *serial)
153{
154 if (!serial->num_interrupt_in) {
155 dev_err(&serial->dev->dev, "no interrupt-in endpoint\n");
156 return -ENODEV;
157 }
158
159 return 0;
160}
161
162static int symbol_port_probe(struct usb_serial_port *port)
163{
164 struct symbol_private *priv;
165
166 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
167 if (!priv)
168 return -ENOMEM;
169
170 spin_lock_init(&priv->lock);
171
172 usb_set_serial_port_data(port, priv);
173
174 return 0;
175}
176
177static int symbol_port_remove(struct usb_serial_port *port)
178{
179 struct symbol_private *priv = usb_get_serial_port_data(port);
180
181 kfree(priv);
182
183 return 0;
184}
185
186static struct usb_serial_driver symbol_device = {
187 .driver = {
188 .owner = THIS_MODULE,
189 .name = "symbol",
190 },
191 .id_table = id_table,
192 .num_ports = 1,
193 .attach = symbol_startup,
194 .port_probe = symbol_port_probe,
195 .port_remove = symbol_port_remove,
196 .open = symbol_open,
197 .close = symbol_close,
198 .throttle = symbol_throttle,
199 .unthrottle = symbol_unthrottle,
200 .read_int_callback = symbol_int_callback,
201};
202
203static struct usb_serial_driver * const serial_drivers[] = {
204 &symbol_device, NULL
205};
206
207module_usb_serial_driver(serial_drivers, id_table);
208
209MODULE_LICENSE("GPL");
210