f81232.c revision 92a19f9cec9a80ad93c06e115822deb729e2c6ad 
1/*
2 * Fintek F81232 USB to serial adaptor driver
3 *
4 * Copyright (C) 2012 Greg Kroah-Hartman (gregkh@linuxfoundation.org)
5 * Copyright (C) 2012 Linux Foundation
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published by
9 * the Free Software Foundation.
10 *
11 */
12
13#include <linux/kernel.h>
14#include <linux/errno.h>
15#include <linux/init.h>
16#include <linux/slab.h>
17#include <linux/tty.h>
18#include <linux/tty_driver.h>
19#include <linux/tty_flip.h>
20#include <linux/serial.h>
21#include <linux/module.h>
22#include <linux/moduleparam.h>
23#include <linux/spinlock.h>
24#include <linux/uaccess.h>
25#include <linux/usb.h>
26#include <linux/usb/serial.h>
27
28static const struct usb_device_id id_table[] = {
29	{ USB_DEVICE(0x1934, 0x0706) },
30	{ }					/* Terminating entry */
31};
32MODULE_DEVICE_TABLE(usb, id_table);
33
34#define CONTROL_DTR			0x01
35#define CONTROL_RTS			0x02
36
37#define UART_STATE			0x08
38#define UART_STATE_TRANSIENT_MASK	0x74
39#define UART_DCD			0x01
40#define UART_DSR			0x02
41#define UART_BREAK_ERROR		0x04
42#define UART_RING			0x08
43#define UART_FRAME_ERROR		0x10
44#define UART_PARITY_ERROR		0x20
45#define UART_OVERRUN_ERROR		0x40
46#define UART_CTS			0x80
47
48struct f81232_private {
49	spinlock_t lock;
50	wait_queue_head_t delta_msr_wait;
51	u8 line_control;
52	u8 line_status;
53};
54
55static void f81232_update_line_status(struct usb_serial_port *port,
56				      unsigned char *data,
57				      unsigned int actual_length)
58{
59}
60
61static void f81232_read_int_callback(struct urb *urb)
62{
63	struct usb_serial_port *port =  urb->context;
64	unsigned char *data = urb->transfer_buffer;
65	unsigned int actual_length = urb->actual_length;
66	int status = urb->status;
67	int retval;
68
69	switch (status) {
70	case 0:
71		/* success */
72		break;
73	case -ECONNRESET:
74	case -ENOENT:
75	case -ESHUTDOWN:
76		/* this urb is terminated, clean up */
77		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
78			__func__, status);
79		return;
80	default:
81		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
82			__func__, status);
83		goto exit;
84	}
85
86	usb_serial_debug_data(&port->dev, __func__,
87			      urb->actual_length, urb->transfer_buffer);
88
89	f81232_update_line_status(port, data, actual_length);
90
91exit:
92	retval = usb_submit_urb(urb, GFP_ATOMIC);
93	if (retval)
94		dev_err(&urb->dev->dev,
95			"%s - usb_submit_urb failed with result %d\n",
96			__func__, retval);
97}
98
99static void f81232_process_read_urb(struct urb *urb)
100{
101	struct usb_serial_port *port = urb->context;
102	struct f81232_private *priv = usb_get_serial_port_data(port);
103	struct tty_struct *tty;
104	unsigned char *data = urb->transfer_buffer;
105	char tty_flag = TTY_NORMAL;
106	unsigned long flags;
107	u8 line_status;
108	int i;
109
110	/* update line status */
111	spin_lock_irqsave(&priv->lock, flags);
112	line_status = priv->line_status;
113	priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
114	spin_unlock_irqrestore(&priv->lock, flags);
115	wake_up_interruptible(&priv->delta_msr_wait);
116
117	if (!urb->actual_length)
118		return;
119
120	tty = tty_port_tty_get(&port->port);
121	if (!tty)
122		return;
123
124	/* break takes precedence over parity, */
125	/* which takes precedence over framing errors */
126	if (line_status & UART_BREAK_ERROR)
127		tty_flag = TTY_BREAK;
128	else if (line_status & UART_PARITY_ERROR)
129		tty_flag = TTY_PARITY;
130	else if (line_status & UART_FRAME_ERROR)
131		tty_flag = TTY_FRAME;
132	dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__, tty_flag);
133
134	/* overrun is special, not associated with a char */
135	if (line_status & UART_OVERRUN_ERROR)
136		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
137
138	if (port->port.console && port->sysrq) {
139		for (i = 0; i < urb->actual_length; ++i)
140			if (!usb_serial_handle_sysrq_char(port, data[i]))
141				tty_insert_flip_char(&port->port, data[i],
142						tty_flag);
143	} else {
144		tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
145							urb->actual_length);
146	}
147
148	tty_flip_buffer_push(tty);
149	tty_kref_put(tty);
150}
151
152static int set_control_lines(struct usb_device *dev, u8 value)
153{
154	/* FIXME - Stubbed out for now */
155	return 0;
156}
157
158static void f81232_break_ctl(struct tty_struct *tty, int break_state)
159{
160	/* FIXME - Stubbed out for now */
161
162	/*
163	 * break_state = -1 to turn on break, and 0 to turn off break
164	 * see drivers/char/tty_io.c to see it used.
165	 * last_set_data_urb_value NEVER has the break bit set in it.
166	 */
167}
168
169static void f81232_set_termios(struct tty_struct *tty,
170		struct usb_serial_port *port, struct ktermios *old_termios)
171{
172	/* FIXME - Stubbed out for now */
173
174	/* Don't change anything if nothing has changed */
175	if (!tty_termios_hw_change(&tty->termios, old_termios))
176		return;
177
178	/* Do the real work here... */
179	tty_termios_copy_hw(&tty->termios, old_termios);
180}
181
182static int f81232_tiocmget(struct tty_struct *tty)
183{
184	/* FIXME - Stubbed out for now */
185	return 0;
186}
187
188static int f81232_tiocmset(struct tty_struct *tty,
189			unsigned int set, unsigned int clear)
190{
191	/* FIXME - Stubbed out for now */
192	return 0;
193}
194
195static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
196{
197	struct ktermios tmp_termios;
198	int result;
199
200	/* Setup termios */
201	if (tty)
202		f81232_set_termios(tty, port, &tmp_termios);
203
204	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
205	if (result) {
206		dev_err(&port->dev, "%s - failed submitting interrupt urb,"
207			" error %d\n", __func__, result);
208		return result;
209	}
210
211	result = usb_serial_generic_open(tty, port);
212	if (result) {
213		usb_kill_urb(port->interrupt_in_urb);
214		return result;
215	}
216
217	port->port.drain_delay = 256;
218	return 0;
219}
220
221static void f81232_close(struct usb_serial_port *port)
222{
223	usb_serial_generic_close(port);
224	usb_kill_urb(port->interrupt_in_urb);
225}
226
227static void f81232_dtr_rts(struct usb_serial_port *port, int on)
228{
229	struct f81232_private *priv = usb_get_serial_port_data(port);
230	unsigned long flags;
231	u8 control;
232
233	spin_lock_irqsave(&priv->lock, flags);
234	/* Change DTR and RTS */
235	if (on)
236		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
237	else
238		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
239	control = priv->line_control;
240	spin_unlock_irqrestore(&priv->lock, flags);
241	set_control_lines(port->serial->dev, control);
242}
243
244static int f81232_carrier_raised(struct usb_serial_port *port)
245{
246	struct f81232_private *priv = usb_get_serial_port_data(port);
247	if (priv->line_status & UART_DCD)
248		return 1;
249	return 0;
250}
251
252static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
253{
254	struct f81232_private *priv = usb_get_serial_port_data(port);
255	unsigned long flags;
256	unsigned int prevstatus;
257	unsigned int status;
258	unsigned int changed;
259
260	spin_lock_irqsave(&priv->lock, flags);
261	prevstatus = priv->line_status;
262	spin_unlock_irqrestore(&priv->lock, flags);
263
264	while (1) {
265		interruptible_sleep_on(&priv->delta_msr_wait);
266		/* see if a signal did it */
267		if (signal_pending(current))
268			return -ERESTARTSYS;
269
270		spin_lock_irqsave(&priv->lock, flags);
271		status = priv->line_status;
272		spin_unlock_irqrestore(&priv->lock, flags);
273
274		changed = prevstatus ^ status;
275
276		if (((arg & TIOCM_RNG) && (changed & UART_RING)) ||
277		    ((arg & TIOCM_DSR) && (changed & UART_DSR)) ||
278		    ((arg & TIOCM_CD)  && (changed & UART_DCD)) ||
279		    ((arg & TIOCM_CTS) && (changed & UART_CTS))) {
280			return 0;
281		}
282		prevstatus = status;
283	}
284	/* NOTREACHED */
285	return 0;
286}
287
288static int f81232_ioctl(struct tty_struct *tty,
289			unsigned int cmd, unsigned long arg)
290{
291	struct serial_struct ser;
292	struct usb_serial_port *port = tty->driver_data;
293
294	dev_dbg(&port->dev, "%s (%d) cmd = 0x%04x\n", __func__,
295		port->number, cmd);
296
297	switch (cmd) {
298	case TIOCGSERIAL:
299		memset(&ser, 0, sizeof ser);
300		ser.type = PORT_16654;
301		ser.line = port->serial->minor;
302		ser.port = port->number;
303		ser.baud_base = 460800;
304
305		if (copy_to_user((void __user *)arg, &ser, sizeof ser))
306			return -EFAULT;
307
308		return 0;
309
310	case TIOCMIWAIT:
311		dev_dbg(&port->dev, "%s (%d) TIOCMIWAIT\n", __func__,
312			port->number);
313		return wait_modem_info(port, arg);
314	default:
315		dev_dbg(&port->dev, "%s not supported = 0x%04x\n",
316			__func__, cmd);
317		break;
318	}
319	return -ENOIOCTLCMD;
320}
321
322static int f81232_port_probe(struct usb_serial_port *port)
323{
324	struct f81232_private *priv;
325
326	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
327	if (!priv)
328		return -ENOMEM;
329
330	spin_lock_init(&priv->lock);
331	init_waitqueue_head(&priv->delta_msr_wait);
332
333	usb_set_serial_port_data(port, priv);
334
335	return 0;
336}
337
338static int f81232_port_remove(struct usb_serial_port *port)
339{
340	struct f81232_private *priv;
341
342	priv = usb_get_serial_port_data(port);
343	kfree(priv);
344
345	return 0;
346}
347
348static struct usb_serial_driver f81232_device = {
349	.driver = {
350		.owner =	THIS_MODULE,
351		.name =		"f81232",
352	},
353	.id_table =		id_table,
354	.num_ports =		1,
355	.bulk_in_size =		256,
356	.bulk_out_size =	256,
357	.open =			f81232_open,
358	.close =		f81232_close,
359	.dtr_rts = 		f81232_dtr_rts,
360	.carrier_raised =	f81232_carrier_raised,
361	.ioctl =		f81232_ioctl,
362	.break_ctl =		f81232_break_ctl,
363	.set_termios =		f81232_set_termios,
364	.tiocmget =		f81232_tiocmget,
365	.tiocmset =		f81232_tiocmset,
366	.process_read_urb =	f81232_process_read_urb,
367	.read_int_callback =	f81232_read_int_callback,
368	.port_probe =		f81232_port_probe,
369	.port_remove =		f81232_port_remove,
370};
371
372static struct usb_serial_driver * const serial_drivers[] = {
373	&f81232_device,
374	NULL,
375};
376
377module_usb_serial_driver(serial_drivers, id_table);
378
379MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
380MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org");
381MODULE_LICENSE("GPL v2");
382