xref: /linux/drivers/usb/serial/upd78f0730.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  * Renesas Electronics uPD78F0730 USB to serial converter driver
3  *
4  * Copyright (C) 2014,2016 Maksim Salau <maksim.salau@gmail.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2
8  * as published by the Free Software Foundation.
9  *
10  * Protocol of the adaptor is described in the application note U19660EJ1V0AN00
11  * μPD78F0730 8-bit Single-Chip Microcontroller
12  * USB-to-Serial Conversion Software
13  * <https://www.renesas.com/en-eu/doc/DocumentServer/026/U19660EJ1V0AN00.pdf>
14  *
15  * The adaptor functionality is limited to the following:
16  * - data bits: 7 or 8
17  * - stop bits: 1 or 2
18  * - parity: even, odd or none
19  * - flow control: none
20  * - baud rates: 0, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 153600
21  * - signals: DTR, RTS and BREAK
22  */
23 
24 #include <linux/module.h>
25 #include <linux/slab.h>
26 #include <linux/tty.h>
27 #include <linux/usb.h>
28 #include <linux/usb/serial.h>
29 
30 #define DRIVER_DESC "Renesas uPD78F0730 USB to serial converter driver"
31 
32 #define DRIVER_AUTHOR "Maksim Salau <maksim.salau@gmail.com>"
33 
34 static const struct usb_device_id id_table[] = {
35 	{ USB_DEVICE(0x0409, 0x0063) }, /* V850ESJX3-STICK */
36 	{ USB_DEVICE(0x045B, 0x0212) }, /* YRPBRL78G13, YRPBRL78G14 */
37 	{ USB_DEVICE(0x064B, 0x7825) }, /* Analog Devices EVAL-ADXL362Z-DB */
38 	{}
39 };
40 
41 MODULE_DEVICE_TABLE(usb, id_table);
42 
43 /*
44  * Each adaptor is associated with a private structure, that holds the current
45  * state of control signals (DTR, RTS and BREAK).
46  */
47 struct upd78f0730_port_private {
48 	struct mutex	lock;		/* mutex to protect line_signals */
49 	u8		line_signals;
50 };
51 
52 /* Op-codes of control commands */
53 #define UPD78F0730_CMD_LINE_CONTROL	0x00
54 #define UPD78F0730_CMD_SET_DTR_RTS	0x01
55 #define UPD78F0730_CMD_SET_XON_XOFF_CHR	0x02
56 #define UPD78F0730_CMD_OPEN_CLOSE	0x03
57 #define UPD78F0730_CMD_SET_ERR_CHR	0x04
58 
59 /* Data sizes in UPD78F0730_CMD_LINE_CONTROL command */
60 #define UPD78F0730_DATA_SIZE_7_BITS	0x00
61 #define UPD78F0730_DATA_SIZE_8_BITS	0x01
62 #define UPD78F0730_DATA_SIZE_MASK	0x01
63 
64 /* Stop-bit modes in UPD78F0730_CMD_LINE_CONTROL command */
65 #define UPD78F0730_STOP_BIT_1_BIT	0x00
66 #define UPD78F0730_STOP_BIT_2_BIT	0x02
67 #define UPD78F0730_STOP_BIT_MASK	0x02
68 
69 /* Parity modes in UPD78F0730_CMD_LINE_CONTROL command */
70 #define UPD78F0730_PARITY_NONE	0x00
71 #define UPD78F0730_PARITY_EVEN	0x04
72 #define UPD78F0730_PARITY_ODD	0x08
73 #define UPD78F0730_PARITY_MASK	0x0C
74 
75 /* Flow control modes in UPD78F0730_CMD_LINE_CONTROL command */
76 #define UPD78F0730_FLOW_CONTROL_NONE	0x00
77 #define UPD78F0730_FLOW_CONTROL_HW	0x10
78 #define UPD78F0730_FLOW_CONTROL_SW	0x20
79 #define UPD78F0730_FLOW_CONTROL_MASK	0x30
80 
81 /* Control signal bits in UPD78F0730_CMD_SET_DTR_RTS command */
82 #define UPD78F0730_RTS		0x01
83 #define UPD78F0730_DTR		0x02
84 #define UPD78F0730_BREAK	0x04
85 
86 /* Port modes in UPD78F0730_CMD_OPEN_CLOSE command */
87 #define UPD78F0730_PORT_CLOSE	0x00
88 #define UPD78F0730_PORT_OPEN	0x01
89 
90 /* Error character substitution modes in UPD78F0730_CMD_SET_ERR_CHR command */
91 #define UPD78F0730_ERR_CHR_DISABLED	0x00
92 #define UPD78F0730_ERR_CHR_ENABLED	0x01
93 
94 /*
95  * Declaration of command structures
96  */
97 
98 /* UPD78F0730_CMD_LINE_CONTROL command */
99 struct upd78f0730_line_control {
100 	u8	opcode;
101 	__le32	baud_rate;
102 	u8	params;
103 } __packed;
104 
105 /* UPD78F0730_CMD_SET_DTR_RTS command */
106 struct upd78f0730_set_dtr_rts {
107 	u8 opcode;
108 	u8 params;
109 };
110 
111 /* UPD78F0730_CMD_SET_XON_OFF_CHR command */
112 struct upd78f0730_set_xon_xoff_chr {
113 	u8 opcode;
114 	u8 xon;
115 	u8 xoff;
116 };
117 
118 /* UPD78F0730_CMD_OPEN_CLOSE command */
119 struct upd78f0730_open_close {
120 	u8 opcode;
121 	u8 state;
122 };
123 
124 /* UPD78F0730_CMD_SET_ERR_CHR command */
125 struct upd78f0730_set_err_chr {
126 	u8 opcode;
127 	u8 state;
128 	u8 err_char;
129 };
130 
131 static int upd78f0730_send_ctl(struct usb_serial_port *port,
132 			const void *data, int size)
133 {
134 	struct usb_device *usbdev = port->serial->dev;
135 	void *buf;
136 	int res;
137 
138 	if (size <= 0 || !data)
139 		return -EINVAL;
140 
141 	buf = kmemdup(data, size, GFP_KERNEL);
142 	if (!buf)
143 		return -ENOMEM;
144 
145 	res = usb_control_msg(usbdev, usb_sndctrlpipe(usbdev, 0), 0x00,
146 			USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
147 			0x0000, 0x0000, buf, size, USB_CTRL_SET_TIMEOUT);
148 
149 	kfree(buf);
150 
151 	if (res != size) {
152 		struct device *dev = &port->dev;
153 
154 		dev_err(dev, "failed to send control request %02x: %d\n",
155 			*(u8 *)data, res);
156 		/* The maximum expected length of a transfer is 6 bytes */
157 		if (res >= 0)
158 			res = -EIO;
159 
160 		return res;
161 	}
162 
163 	return 0;
164 }
165 
166 static int upd78f0730_port_probe(struct usb_serial_port *port)
167 {
168 	struct upd78f0730_port_private *private;
169 
170 	private = kzalloc(sizeof(*private), GFP_KERNEL);
171 	if (!private)
172 		return -ENOMEM;
173 
174 	mutex_init(&private->lock);
175 	usb_set_serial_port_data(port, private);
176 
177 	return 0;
178 }
179 
180 static int upd78f0730_port_remove(struct usb_serial_port *port)
181 {
182 	struct upd78f0730_port_private *private;
183 
184 	private = usb_get_serial_port_data(port);
185 	mutex_destroy(&private->lock);
186 	kfree(private);
187 
188 	return 0;
189 }
190 
191 static int upd78f0730_tiocmget(struct tty_struct *tty)
192 {
193 	struct device *dev = tty->dev;
194 	struct upd78f0730_port_private *private;
195 	struct usb_serial_port *port = tty->driver_data;
196 	int signals;
197 	int res;
198 
199 	private = usb_get_serial_port_data(port);
200 
201 	mutex_lock(&private->lock);
202 	signals = private->line_signals;
203 	mutex_unlock(&private->lock);
204 
205 	res = ((signals & UPD78F0730_DTR) ? TIOCM_DTR : 0) |
206 		((signals & UPD78F0730_RTS) ? TIOCM_RTS : 0);
207 
208 	dev_dbg(dev, "%s - res = %x\n", __func__, res);
209 
210 	return res;
211 }
212 
213 static int upd78f0730_tiocmset(struct tty_struct *tty,
214 			unsigned int set, unsigned int clear)
215 {
216 	struct device *dev = tty->dev;
217 	struct usb_serial_port *port = tty->driver_data;
218 	struct upd78f0730_port_private *private;
219 	struct upd78f0730_set_dtr_rts request;
220 	int res;
221 
222 	private = usb_get_serial_port_data(port);
223 
224 	mutex_lock(&private->lock);
225 	if (set & TIOCM_DTR) {
226 		private->line_signals |= UPD78F0730_DTR;
227 		dev_dbg(dev, "%s - set DTR\n", __func__);
228 	}
229 	if (set & TIOCM_RTS) {
230 		private->line_signals |= UPD78F0730_RTS;
231 		dev_dbg(dev, "%s - set RTS\n", __func__);
232 	}
233 	if (clear & TIOCM_DTR) {
234 		private->line_signals &= ~UPD78F0730_DTR;
235 		dev_dbg(dev, "%s - clear DTR\n", __func__);
236 	}
237 	if (clear & TIOCM_RTS) {
238 		private->line_signals &= ~UPD78F0730_RTS;
239 		dev_dbg(dev, "%s - clear RTS\n", __func__);
240 	}
241 	request.opcode = UPD78F0730_CMD_SET_DTR_RTS;
242 	request.params = private->line_signals;
243 
244 	res = upd78f0730_send_ctl(port, &request, sizeof(request));
245 	mutex_unlock(&private->lock);
246 
247 	return res;
248 }
249 
250 static void upd78f0730_break_ctl(struct tty_struct *tty, int break_state)
251 {
252 	struct device *dev = tty->dev;
253 	struct upd78f0730_port_private *private;
254 	struct usb_serial_port *port = tty->driver_data;
255 	struct upd78f0730_set_dtr_rts request;
256 
257 	private = usb_get_serial_port_data(port);
258 
259 	mutex_lock(&private->lock);
260 	if (break_state) {
261 		private->line_signals |= UPD78F0730_BREAK;
262 		dev_dbg(dev, "%s - set BREAK\n", __func__);
263 	} else {
264 		private->line_signals &= ~UPD78F0730_BREAK;
265 		dev_dbg(dev, "%s - clear BREAK\n", __func__);
266 	}
267 	request.opcode = UPD78F0730_CMD_SET_DTR_RTS;
268 	request.params = private->line_signals;
269 
270 	upd78f0730_send_ctl(port, &request, sizeof(request));
271 	mutex_unlock(&private->lock);
272 }
273 
274 static void upd78f0730_dtr_rts(struct usb_serial_port *port, int on)
275 {
276 	struct tty_struct *tty = port->port.tty;
277 	unsigned int set = 0;
278 	unsigned int clear = 0;
279 
280 	if (on)
281 		set = TIOCM_DTR | TIOCM_RTS;
282 	else
283 		clear = TIOCM_DTR | TIOCM_RTS;
284 
285 	upd78f0730_tiocmset(tty, set, clear);
286 }
287 
288 static speed_t upd78f0730_get_baud_rate(struct tty_struct *tty)
289 {
290 	const speed_t baud_rate = tty_get_baud_rate(tty);
291 	const speed_t supported[] = {
292 		0, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 153600
293 	};
294 	int i;
295 
296 	for (i = ARRAY_SIZE(supported) - 1; i >= 0; i--) {
297 		if (baud_rate == supported[i])
298 			return baud_rate;
299 	}
300 
301 	/* If the baud rate is not supported, switch to the default one */
302 	tty_encode_baud_rate(tty, 9600, 9600);
303 
304 	return tty_get_baud_rate(tty);
305 }
306 
307 static void upd78f0730_set_termios(struct tty_struct *tty,
308 				struct usb_serial_port *port,
309 				struct ktermios *old_termios)
310 {
311 	struct device *dev = &port->dev;
312 	struct upd78f0730_line_control request;
313 	speed_t baud_rate;
314 
315 	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
316 		return;
317 
318 	if (C_BAUD(tty) == B0)
319 		upd78f0730_dtr_rts(port, 0);
320 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
321 		upd78f0730_dtr_rts(port, 1);
322 
323 	baud_rate = upd78f0730_get_baud_rate(tty);
324 	request.opcode = UPD78F0730_CMD_LINE_CONTROL;
325 	request.baud_rate = cpu_to_le32(baud_rate);
326 	request.params = 0;
327 	dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud_rate);
328 
329 	switch (C_CSIZE(tty)) {
330 	case CS7:
331 		request.params |= UPD78F0730_DATA_SIZE_7_BITS;
332 		dev_dbg(dev, "%s - 7 data bits\n", __func__);
333 		break;
334 	default:
335 		tty->termios.c_cflag &= ~CSIZE;
336 		tty->termios.c_cflag |= CS8;
337 		dev_warn(dev, "data size is not supported, using 8 bits\n");
338 		/* fall through */
339 	case CS8:
340 		request.params |= UPD78F0730_DATA_SIZE_8_BITS;
341 		dev_dbg(dev, "%s - 8 data bits\n", __func__);
342 		break;
343 	}
344 
345 	if (C_PARENB(tty)) {
346 		if (C_PARODD(tty)) {
347 			request.params |= UPD78F0730_PARITY_ODD;
348 			dev_dbg(dev, "%s - odd parity\n", __func__);
349 		} else {
350 			request.params |= UPD78F0730_PARITY_EVEN;
351 			dev_dbg(dev, "%s - even parity\n", __func__);
352 		}
353 
354 		if (C_CMSPAR(tty)) {
355 			tty->termios.c_cflag &= ~CMSPAR;
356 			dev_warn(dev, "MARK/SPACE parity is not supported\n");
357 		}
358 	} else {
359 		request.params |= UPD78F0730_PARITY_NONE;
360 		dev_dbg(dev, "%s - no parity\n", __func__);
361 	}
362 
363 	if (C_CSTOPB(tty)) {
364 		request.params |= UPD78F0730_STOP_BIT_2_BIT;
365 		dev_dbg(dev, "%s - 2 stop bits\n", __func__);
366 	} else {
367 		request.params |= UPD78F0730_STOP_BIT_1_BIT;
368 		dev_dbg(dev, "%s - 1 stop bit\n", __func__);
369 	}
370 
371 	if (C_CRTSCTS(tty)) {
372 		tty->termios.c_cflag &= ~CRTSCTS;
373 		dev_warn(dev, "RTSCTS flow control is not supported\n");
374 	}
375 	if (I_IXOFF(tty) || I_IXON(tty)) {
376 		tty->termios.c_iflag &= ~(IXOFF | IXON);
377 		dev_warn(dev, "XON/XOFF flow control is not supported\n");
378 	}
379 	request.params |= UPD78F0730_FLOW_CONTROL_NONE;
380 	dev_dbg(dev, "%s - no flow control\n", __func__);
381 
382 	upd78f0730_send_ctl(port, &request, sizeof(request));
383 }
384 
385 static int upd78f0730_open(struct tty_struct *tty, struct usb_serial_port *port)
386 {
387 	struct upd78f0730_open_close request = {
388 		.opcode = UPD78F0730_CMD_OPEN_CLOSE,
389 		.state = UPD78F0730_PORT_OPEN
390 	};
391 	int res;
392 
393 	res = upd78f0730_send_ctl(port, &request, sizeof(request));
394 	if (res)
395 		return res;
396 
397 	if (tty)
398 		upd78f0730_set_termios(tty, port, NULL);
399 
400 	return usb_serial_generic_open(tty, port);
401 }
402 
403 static void upd78f0730_close(struct usb_serial_port *port)
404 {
405 	struct upd78f0730_open_close request = {
406 		.opcode = UPD78F0730_CMD_OPEN_CLOSE,
407 		.state = UPD78F0730_PORT_CLOSE
408 	};
409 
410 	usb_serial_generic_close(port);
411 	upd78f0730_send_ctl(port, &request, sizeof(request));
412 }
413 
414 static struct usb_serial_driver upd78f0730_device = {
415 	.driver	 = {
416 		.owner	= THIS_MODULE,
417 		.name	= "upd78f0730",
418 	},
419 	.id_table	= id_table,
420 	.num_ports	= 1,
421 	.port_probe	= upd78f0730_port_probe,
422 	.port_remove	= upd78f0730_port_remove,
423 	.open		= upd78f0730_open,
424 	.close		= upd78f0730_close,
425 	.set_termios	= upd78f0730_set_termios,
426 	.tiocmget	= upd78f0730_tiocmget,
427 	.tiocmset	= upd78f0730_tiocmset,
428 	.dtr_rts	= upd78f0730_dtr_rts,
429 	.break_ctl	= upd78f0730_break_ctl,
430 };
431 
432 static struct usb_serial_driver * const serial_drivers[] = {
433 	&upd78f0730_device,
434 	NULL
435 };
436 
437 module_usb_serial_driver(serial_drivers, id_table);
438 
439 MODULE_DESCRIPTION(DRIVER_DESC);
440 MODULE_AUTHOR(DRIVER_AUTHOR);
441 MODULE_LICENSE("GPL v2");
442