xref: /openbmc/linux/drivers/usb/serial/upd78f0730.c (revision e2c75e76)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Renesas Electronics uPD78F0730 USB to serial converter driver
4  *
5  * Copyright (C) 2014,2016 Maksim Salau <maksim.salau@gmail.com>
6  *
7  * Protocol of the adaptor is described in the application note U19660EJ1V0AN00
8  * μPD78F0730 8-bit Single-Chip Microcontroller
9  * USB-to-Serial Conversion Software
10  * <https://www.renesas.com/en-eu/doc/DocumentServer/026/U19660EJ1V0AN00.pdf>
11  *
12  * The adaptor functionality is limited to the following:
13  * - data bits: 7 or 8
14  * - stop bits: 1 or 2
15  * - parity: even, odd or none
16  * - flow control: none
17  * - baud rates: 0, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 153600
18  * - signals: DTR, RTS and BREAK
19  */
20 
21 #include <linux/module.h>
22 #include <linux/slab.h>
23 #include <linux/tty.h>
24 #include <linux/usb.h>
25 #include <linux/usb/serial.h>
26 
27 #define DRIVER_DESC "Renesas uPD78F0730 USB to serial converter driver"
28 
29 #define DRIVER_AUTHOR "Maksim Salau <maksim.salau@gmail.com>"
30 
31 static const struct usb_device_id id_table[] = {
32 	{ USB_DEVICE(0x0409, 0x0063) }, /* V850ESJX3-STICK */
33 	{ USB_DEVICE(0x045B, 0x0212) }, /* YRPBRL78G13, YRPBRL78G14 */
34 	{ USB_DEVICE(0x064B, 0x7825) }, /* Analog Devices EVAL-ADXL362Z-DB */
35 	{}
36 };
37 
38 MODULE_DEVICE_TABLE(usb, id_table);
39 
40 /*
41  * Each adaptor is associated with a private structure, that holds the current
42  * state of control signals (DTR, RTS and BREAK).
43  */
44 struct upd78f0730_port_private {
45 	struct mutex	lock;		/* mutex to protect line_signals */
46 	u8		line_signals;
47 };
48 
49 /* Op-codes of control commands */
50 #define UPD78F0730_CMD_LINE_CONTROL	0x00
51 #define UPD78F0730_CMD_SET_DTR_RTS	0x01
52 #define UPD78F0730_CMD_SET_XON_XOFF_CHR	0x02
53 #define UPD78F0730_CMD_OPEN_CLOSE	0x03
54 #define UPD78F0730_CMD_SET_ERR_CHR	0x04
55 
56 /* Data sizes in UPD78F0730_CMD_LINE_CONTROL command */
57 #define UPD78F0730_DATA_SIZE_7_BITS	0x00
58 #define UPD78F0730_DATA_SIZE_8_BITS	0x01
59 #define UPD78F0730_DATA_SIZE_MASK	0x01
60 
61 /* Stop-bit modes in UPD78F0730_CMD_LINE_CONTROL command */
62 #define UPD78F0730_STOP_BIT_1_BIT	0x00
63 #define UPD78F0730_STOP_BIT_2_BIT	0x02
64 #define UPD78F0730_STOP_BIT_MASK	0x02
65 
66 /* Parity modes in UPD78F0730_CMD_LINE_CONTROL command */
67 #define UPD78F0730_PARITY_NONE	0x00
68 #define UPD78F0730_PARITY_EVEN	0x04
69 #define UPD78F0730_PARITY_ODD	0x08
70 #define UPD78F0730_PARITY_MASK	0x0C
71 
72 /* Flow control modes in UPD78F0730_CMD_LINE_CONTROL command */
73 #define UPD78F0730_FLOW_CONTROL_NONE	0x00
74 #define UPD78F0730_FLOW_CONTROL_HW	0x10
75 #define UPD78F0730_FLOW_CONTROL_SW	0x20
76 #define UPD78F0730_FLOW_CONTROL_MASK	0x30
77 
78 /* Control signal bits in UPD78F0730_CMD_SET_DTR_RTS command */
79 #define UPD78F0730_RTS		0x01
80 #define UPD78F0730_DTR		0x02
81 #define UPD78F0730_BREAK	0x04
82 
83 /* Port modes in UPD78F0730_CMD_OPEN_CLOSE command */
84 #define UPD78F0730_PORT_CLOSE	0x00
85 #define UPD78F0730_PORT_OPEN	0x01
86 
87 /* Error character substitution modes in UPD78F0730_CMD_SET_ERR_CHR command */
88 #define UPD78F0730_ERR_CHR_DISABLED	0x00
89 #define UPD78F0730_ERR_CHR_ENABLED	0x01
90 
91 /*
92  * Declaration of command structures
93  */
94 
95 /* UPD78F0730_CMD_LINE_CONTROL command */
96 struct upd78f0730_line_control {
97 	u8	opcode;
98 	__le32	baud_rate;
99 	u8	params;
100 } __packed;
101 
102 /* UPD78F0730_CMD_SET_DTR_RTS command */
103 struct upd78f0730_set_dtr_rts {
104 	u8 opcode;
105 	u8 params;
106 };
107 
108 /* UPD78F0730_CMD_SET_XON_OFF_CHR command */
109 struct upd78f0730_set_xon_xoff_chr {
110 	u8 opcode;
111 	u8 xon;
112 	u8 xoff;
113 };
114 
115 /* UPD78F0730_CMD_OPEN_CLOSE command */
116 struct upd78f0730_open_close {
117 	u8 opcode;
118 	u8 state;
119 };
120 
121 /* UPD78F0730_CMD_SET_ERR_CHR command */
122 struct upd78f0730_set_err_chr {
123 	u8 opcode;
124 	u8 state;
125 	u8 err_char;
126 };
127 
128 static int upd78f0730_send_ctl(struct usb_serial_port *port,
129 			const void *data, int size)
130 {
131 	struct usb_device *usbdev = port->serial->dev;
132 	void *buf;
133 	int res;
134 
135 	if (size <= 0 || !data)
136 		return -EINVAL;
137 
138 	buf = kmemdup(data, size, GFP_KERNEL);
139 	if (!buf)
140 		return -ENOMEM;
141 
142 	res = usb_control_msg(usbdev, usb_sndctrlpipe(usbdev, 0), 0x00,
143 			USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
144 			0x0000, 0x0000, buf, size, USB_CTRL_SET_TIMEOUT);
145 
146 	kfree(buf);
147 
148 	if (res != size) {
149 		struct device *dev = &port->dev;
150 
151 		dev_err(dev, "failed to send control request %02x: %d\n",
152 			*(u8 *)data, res);
153 		/* The maximum expected length of a transfer is 6 bytes */
154 		if (res >= 0)
155 			res = -EIO;
156 
157 		return res;
158 	}
159 
160 	return 0;
161 }
162 
163 static int upd78f0730_port_probe(struct usb_serial_port *port)
164 {
165 	struct upd78f0730_port_private *private;
166 
167 	private = kzalloc(sizeof(*private), GFP_KERNEL);
168 	if (!private)
169 		return -ENOMEM;
170 
171 	mutex_init(&private->lock);
172 	usb_set_serial_port_data(port, private);
173 
174 	return 0;
175 }
176 
177 static int upd78f0730_port_remove(struct usb_serial_port *port)
178 {
179 	struct upd78f0730_port_private *private;
180 
181 	private = usb_get_serial_port_data(port);
182 	mutex_destroy(&private->lock);
183 	kfree(private);
184 
185 	return 0;
186 }
187 
188 static int upd78f0730_tiocmget(struct tty_struct *tty)
189 {
190 	struct device *dev = tty->dev;
191 	struct upd78f0730_port_private *private;
192 	struct usb_serial_port *port = tty->driver_data;
193 	int signals;
194 	int res;
195 
196 	private = usb_get_serial_port_data(port);
197 
198 	mutex_lock(&private->lock);
199 	signals = private->line_signals;
200 	mutex_unlock(&private->lock);
201 
202 	res = ((signals & UPD78F0730_DTR) ? TIOCM_DTR : 0) |
203 		((signals & UPD78F0730_RTS) ? TIOCM_RTS : 0);
204 
205 	dev_dbg(dev, "%s - res = %x\n", __func__, res);
206 
207 	return res;
208 }
209 
210 static int upd78f0730_tiocmset(struct tty_struct *tty,
211 			unsigned int set, unsigned int clear)
212 {
213 	struct device *dev = tty->dev;
214 	struct usb_serial_port *port = tty->driver_data;
215 	struct upd78f0730_port_private *private;
216 	struct upd78f0730_set_dtr_rts request;
217 	int res;
218 
219 	private = usb_get_serial_port_data(port);
220 
221 	mutex_lock(&private->lock);
222 	if (set & TIOCM_DTR) {
223 		private->line_signals |= UPD78F0730_DTR;
224 		dev_dbg(dev, "%s - set DTR\n", __func__);
225 	}
226 	if (set & TIOCM_RTS) {
227 		private->line_signals |= UPD78F0730_RTS;
228 		dev_dbg(dev, "%s - set RTS\n", __func__);
229 	}
230 	if (clear & TIOCM_DTR) {
231 		private->line_signals &= ~UPD78F0730_DTR;
232 		dev_dbg(dev, "%s - clear DTR\n", __func__);
233 	}
234 	if (clear & TIOCM_RTS) {
235 		private->line_signals &= ~UPD78F0730_RTS;
236 		dev_dbg(dev, "%s - clear RTS\n", __func__);
237 	}
238 	request.opcode = UPD78F0730_CMD_SET_DTR_RTS;
239 	request.params = private->line_signals;
240 
241 	res = upd78f0730_send_ctl(port, &request, sizeof(request));
242 	mutex_unlock(&private->lock);
243 
244 	return res;
245 }
246 
247 static void upd78f0730_break_ctl(struct tty_struct *tty, int break_state)
248 {
249 	struct device *dev = tty->dev;
250 	struct upd78f0730_port_private *private;
251 	struct usb_serial_port *port = tty->driver_data;
252 	struct upd78f0730_set_dtr_rts request;
253 
254 	private = usb_get_serial_port_data(port);
255 
256 	mutex_lock(&private->lock);
257 	if (break_state) {
258 		private->line_signals |= UPD78F0730_BREAK;
259 		dev_dbg(dev, "%s - set BREAK\n", __func__);
260 	} else {
261 		private->line_signals &= ~UPD78F0730_BREAK;
262 		dev_dbg(dev, "%s - clear BREAK\n", __func__);
263 	}
264 	request.opcode = UPD78F0730_CMD_SET_DTR_RTS;
265 	request.params = private->line_signals;
266 
267 	upd78f0730_send_ctl(port, &request, sizeof(request));
268 	mutex_unlock(&private->lock);
269 }
270 
271 static void upd78f0730_dtr_rts(struct usb_serial_port *port, int on)
272 {
273 	struct tty_struct *tty = port->port.tty;
274 	unsigned int set = 0;
275 	unsigned int clear = 0;
276 
277 	if (on)
278 		set = TIOCM_DTR | TIOCM_RTS;
279 	else
280 		clear = TIOCM_DTR | TIOCM_RTS;
281 
282 	upd78f0730_tiocmset(tty, set, clear);
283 }
284 
285 static speed_t upd78f0730_get_baud_rate(struct tty_struct *tty)
286 {
287 	const speed_t baud_rate = tty_get_baud_rate(tty);
288 	static const speed_t supported[] = {
289 		0, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 153600
290 	};
291 	int i;
292 
293 	for (i = ARRAY_SIZE(supported) - 1; i >= 0; i--) {
294 		if (baud_rate == supported[i])
295 			return baud_rate;
296 	}
297 
298 	/* If the baud rate is not supported, switch to the default one */
299 	tty_encode_baud_rate(tty, 9600, 9600);
300 
301 	return tty_get_baud_rate(tty);
302 }
303 
304 static void upd78f0730_set_termios(struct tty_struct *tty,
305 				struct usb_serial_port *port,
306 				struct ktermios *old_termios)
307 {
308 	struct device *dev = &port->dev;
309 	struct upd78f0730_line_control request;
310 	speed_t baud_rate;
311 
312 	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
313 		return;
314 
315 	if (C_BAUD(tty) == B0)
316 		upd78f0730_dtr_rts(port, 0);
317 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
318 		upd78f0730_dtr_rts(port, 1);
319 
320 	baud_rate = upd78f0730_get_baud_rate(tty);
321 	request.opcode = UPD78F0730_CMD_LINE_CONTROL;
322 	request.baud_rate = cpu_to_le32(baud_rate);
323 	request.params = 0;
324 	dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud_rate);
325 
326 	switch (C_CSIZE(tty)) {
327 	case CS7:
328 		request.params |= UPD78F0730_DATA_SIZE_7_BITS;
329 		dev_dbg(dev, "%s - 7 data bits\n", __func__);
330 		break;
331 	default:
332 		tty->termios.c_cflag &= ~CSIZE;
333 		tty->termios.c_cflag |= CS8;
334 		dev_warn(dev, "data size is not supported, using 8 bits\n");
335 		/* fall through */
336 	case CS8:
337 		request.params |= UPD78F0730_DATA_SIZE_8_BITS;
338 		dev_dbg(dev, "%s - 8 data bits\n", __func__);
339 		break;
340 	}
341 
342 	if (C_PARENB(tty)) {
343 		if (C_PARODD(tty)) {
344 			request.params |= UPD78F0730_PARITY_ODD;
345 			dev_dbg(dev, "%s - odd parity\n", __func__);
346 		} else {
347 			request.params |= UPD78F0730_PARITY_EVEN;
348 			dev_dbg(dev, "%s - even parity\n", __func__);
349 		}
350 
351 		if (C_CMSPAR(tty)) {
352 			tty->termios.c_cflag &= ~CMSPAR;
353 			dev_warn(dev, "MARK/SPACE parity is not supported\n");
354 		}
355 	} else {
356 		request.params |= UPD78F0730_PARITY_NONE;
357 		dev_dbg(dev, "%s - no parity\n", __func__);
358 	}
359 
360 	if (C_CSTOPB(tty)) {
361 		request.params |= UPD78F0730_STOP_BIT_2_BIT;
362 		dev_dbg(dev, "%s - 2 stop bits\n", __func__);
363 	} else {
364 		request.params |= UPD78F0730_STOP_BIT_1_BIT;
365 		dev_dbg(dev, "%s - 1 stop bit\n", __func__);
366 	}
367 
368 	if (C_CRTSCTS(tty)) {
369 		tty->termios.c_cflag &= ~CRTSCTS;
370 		dev_warn(dev, "RTSCTS flow control is not supported\n");
371 	}
372 	if (I_IXOFF(tty) || I_IXON(tty)) {
373 		tty->termios.c_iflag &= ~(IXOFF | IXON);
374 		dev_warn(dev, "XON/XOFF flow control is not supported\n");
375 	}
376 	request.params |= UPD78F0730_FLOW_CONTROL_NONE;
377 	dev_dbg(dev, "%s - no flow control\n", __func__);
378 
379 	upd78f0730_send_ctl(port, &request, sizeof(request));
380 }
381 
382 static int upd78f0730_open(struct tty_struct *tty, struct usb_serial_port *port)
383 {
384 	static const struct upd78f0730_open_close request = {
385 		.opcode = UPD78F0730_CMD_OPEN_CLOSE,
386 		.state = UPD78F0730_PORT_OPEN
387 	};
388 	int res;
389 
390 	res = upd78f0730_send_ctl(port, &request, sizeof(request));
391 	if (res)
392 		return res;
393 
394 	if (tty)
395 		upd78f0730_set_termios(tty, port, NULL);
396 
397 	return usb_serial_generic_open(tty, port);
398 }
399 
400 static void upd78f0730_close(struct usb_serial_port *port)
401 {
402 	static const struct upd78f0730_open_close request = {
403 		.opcode = UPD78F0730_CMD_OPEN_CLOSE,
404 		.state = UPD78F0730_PORT_CLOSE
405 	};
406 
407 	usb_serial_generic_close(port);
408 	upd78f0730_send_ctl(port, &request, sizeof(request));
409 }
410 
411 static struct usb_serial_driver upd78f0730_device = {
412 	.driver	 = {
413 		.owner	= THIS_MODULE,
414 		.name	= "upd78f0730",
415 	},
416 	.id_table	= id_table,
417 	.num_ports	= 1,
418 	.port_probe	= upd78f0730_port_probe,
419 	.port_remove	= upd78f0730_port_remove,
420 	.open		= upd78f0730_open,
421 	.close		= upd78f0730_close,
422 	.set_termios	= upd78f0730_set_termios,
423 	.tiocmget	= upd78f0730_tiocmget,
424 	.tiocmset	= upd78f0730_tiocmset,
425 	.dtr_rts	= upd78f0730_dtr_rts,
426 	.break_ctl	= upd78f0730_break_ctl,
427 };
428 
429 static struct usb_serial_driver * const serial_drivers[] = {
430 	&upd78f0730_device,
431 	NULL
432 };
433 
434 module_usb_serial_driver(serial_drivers, id_table);
435 
436 MODULE_DESCRIPTION(DRIVER_DESC);
437 MODULE_AUTHOR(DRIVER_AUTHOR);
438 MODULE_LICENSE("GPL v2");
439