xref: /openbmc/linux/drivers/usb/serial/f81232.c (revision c819e2cf)
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 
27 static const struct usb_device_id id_table[] = {
28 	{ USB_DEVICE(0x1934, 0x0706) },
29 	{ }					/* Terminating entry */
30 };
31 MODULE_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 
47 struct f81232_private {
48 	spinlock_t lock;
49 	u8 line_control;
50 	u8 line_status;
51 };
52 
53 static 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 
66 static 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 
96 exit:
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 
104 static 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 
150 static int set_control_lines(struct usb_device *dev, u8 value)
151 {
152 	/* FIXME - Stubbed out for now */
153 	return 0;
154 }
155 
156 static 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 
167 static 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 
181 static int f81232_tiocmget(struct tty_struct *tty)
182 {
183 	/* FIXME - Stubbed out for now */
184 	return 0;
185 }
186 
187 static 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 
194 static 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 
218 static 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 
224 static 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 
241 static 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 
249 static 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 
273 static 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 
290 static 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 
300 static 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 
325 static struct usb_serial_driver * const serial_drivers[] = {
326 	&f81232_device,
327 	NULL,
328 };
329 
330 module_usb_serial_driver(serial_drivers, id_table);
331 
332 MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
333 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org");
334 MODULE_LICENSE("GPL v2");
335