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