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  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
 31static 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
 38MODULE_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 */
 44struct 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 */
 96struct upd78f0730_line_control {
 97	u8	opcode;
 98	__le32	baud_rate;
 99	u8	params;
100} __packed;
101
102/* UPD78F0730_CMD_SET_DTR_RTS command */
103struct upd78f0730_set_dtr_rts {
104	u8 opcode;
105	u8 params;
106};
107
108/* UPD78F0730_CMD_SET_XON_OFF_CHR command */
109struct upd78f0730_set_xon_xoff_chr {
110	u8 opcode;
111	u8 xon;
112	u8 xoff;
113};
114
115/* UPD78F0730_CMD_OPEN_CLOSE command */
116struct upd78f0730_open_close {
117	u8 opcode;
118	u8 state;
119};
120
121/* UPD78F0730_CMD_SET_ERR_CHR command */
122struct upd78f0730_set_err_chr {
123	u8 opcode;
124	u8 state;
125	u8 err_char;
126};
127
128static 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 < 0) {
149		struct device *dev = &port->dev;
150
151		dev_err(dev, "failed to send control request %02x: %d\n",
152			*(u8 *)data, res);
153
154		return res;
155	}
156
157	return 0;
158}
159
160static int upd78f0730_port_probe(struct usb_serial_port *port)
161{
162	struct upd78f0730_port_private *private;
163
164	private = kzalloc(sizeof(*private), GFP_KERNEL);
165	if (!private)
166		return -ENOMEM;
167
168	mutex_init(&private->lock);
169	usb_set_serial_port_data(port, private);
170
171	return 0;
172}
173
174static void upd78f0730_port_remove(struct usb_serial_port *port)
175{
176	struct upd78f0730_port_private *private;
177
178	private = usb_get_serial_port_data(port);
179	mutex_destroy(&private->lock);
180	kfree(private);
181}
182
183static int upd78f0730_tiocmget(struct tty_struct *tty)
184{
185	struct upd78f0730_port_private *private;
186	struct usb_serial_port *port = tty->driver_data;
187	int signals;
188	int res;
189
190	private = usb_get_serial_port_data(port);
191
192	mutex_lock(&private->lock);
193	signals = private->line_signals;
194	mutex_unlock(&private->lock);
195
196	res = ((signals & UPD78F0730_DTR) ? TIOCM_DTR : 0) |
197		((signals & UPD78F0730_RTS) ? TIOCM_RTS : 0);
198
199	dev_dbg(&port->dev, "%s - res = %x\n", __func__, res);
200
201	return res;
202}
203
204static int upd78f0730_tiocmset(struct tty_struct *tty,
205			unsigned int set, unsigned int clear)
206{
207	struct usb_serial_port *port = tty->driver_data;
208	struct upd78f0730_port_private *private;
209	struct upd78f0730_set_dtr_rts request;
210	struct device *dev = &port->dev;
211	int res;
212
213	private = usb_get_serial_port_data(port);
214
215	mutex_lock(&private->lock);
216	if (set & TIOCM_DTR) {
217		private->line_signals |= UPD78F0730_DTR;
218		dev_dbg(dev, "%s - set DTR\n", __func__);
219	}
220	if (set & TIOCM_RTS) {
221		private->line_signals |= UPD78F0730_RTS;
222		dev_dbg(dev, "%s - set RTS\n", __func__);
223	}
224	if (clear & TIOCM_DTR) {
225		private->line_signals &= ~UPD78F0730_DTR;
226		dev_dbg(dev, "%s - clear DTR\n", __func__);
227	}
228	if (clear & TIOCM_RTS) {
229		private->line_signals &= ~UPD78F0730_RTS;
230		dev_dbg(dev, "%s - clear RTS\n", __func__);
231	}
232	request.opcode = UPD78F0730_CMD_SET_DTR_RTS;
233	request.params = private->line_signals;
234
235	res = upd78f0730_send_ctl(port, &request, sizeof(request));
236	mutex_unlock(&private->lock);
237
238	return res;
239}
240
241static void upd78f0730_break_ctl(struct tty_struct *tty, int break_state)
242{
243	struct upd78f0730_port_private *private;
244	struct usb_serial_port *port = tty->driver_data;
245	struct upd78f0730_set_dtr_rts request;
246	struct device *dev = &port->dev;
247
248	private = usb_get_serial_port_data(port);
249
250	mutex_lock(&private->lock);
251	if (break_state) {
252		private->line_signals |= UPD78F0730_BREAK;
253		dev_dbg(dev, "%s - set BREAK\n", __func__);
254	} else {
255		private->line_signals &= ~UPD78F0730_BREAK;
256		dev_dbg(dev, "%s - clear BREAK\n", __func__);
257	}
258	request.opcode = UPD78F0730_CMD_SET_DTR_RTS;
259	request.params = private->line_signals;
260
261	upd78f0730_send_ctl(port, &request, sizeof(request));
262	mutex_unlock(&private->lock);
263}
264
265static void upd78f0730_dtr_rts(struct usb_serial_port *port, int on)
266{
267	struct tty_struct *tty = port->port.tty;
268	unsigned int set = 0;
269	unsigned int clear = 0;
270
271	if (on)
272		set = TIOCM_DTR | TIOCM_RTS;
273	else
274		clear = TIOCM_DTR | TIOCM_RTS;
275
276	upd78f0730_tiocmset(tty, set, clear);
277}
278
279static speed_t upd78f0730_get_baud_rate(struct tty_struct *tty)
280{
281	const speed_t baud_rate = tty_get_baud_rate(tty);
282	static const speed_t supported[] = {
283		0, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 153600
284	};
285	int i;
286
287	for (i = ARRAY_SIZE(supported) - 1; i >= 0; i--) {
288		if (baud_rate == supported[i])
289			return baud_rate;
290	}
291
292	/* If the baud rate is not supported, switch to the default one */
293	tty_encode_baud_rate(tty, 9600, 9600);
294
295	return tty_get_baud_rate(tty);
296}
297
298static void upd78f0730_set_termios(struct tty_struct *tty,
299				   struct usb_serial_port *port,
300				   const struct ktermios *old_termios)
301{
302	struct device *dev = &port->dev;
303	struct upd78f0730_line_control request;
304	speed_t baud_rate;
305
306	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
307		return;
308
309	if (C_BAUD(tty) == B0)
310		upd78f0730_dtr_rts(port, 0);
311	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
312		upd78f0730_dtr_rts(port, 1);
313
314	baud_rate = upd78f0730_get_baud_rate(tty);
315	request.opcode = UPD78F0730_CMD_LINE_CONTROL;
316	request.baud_rate = cpu_to_le32(baud_rate);
317	request.params = 0;
318	dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud_rate);
319
320	switch (C_CSIZE(tty)) {
321	case CS7:
322		request.params |= UPD78F0730_DATA_SIZE_7_BITS;
323		dev_dbg(dev, "%s - 7 data bits\n", __func__);
324		break;
325	default:
326		tty->termios.c_cflag &= ~CSIZE;
327		tty->termios.c_cflag |= CS8;
328		dev_warn(dev, "data size is not supported, using 8 bits\n");
329		fallthrough;
330	case CS8:
331		request.params |= UPD78F0730_DATA_SIZE_8_BITS;
332		dev_dbg(dev, "%s - 8 data bits\n", __func__);
333		break;
334	}
335
336	if (C_PARENB(tty)) {
337		if (C_PARODD(tty)) {
338			request.params |= UPD78F0730_PARITY_ODD;
339			dev_dbg(dev, "%s - odd parity\n", __func__);
340		} else {
341			request.params |= UPD78F0730_PARITY_EVEN;
342			dev_dbg(dev, "%s - even parity\n", __func__);
343		}
344
345		if (C_CMSPAR(tty)) {
346			tty->termios.c_cflag &= ~CMSPAR;
347			dev_warn(dev, "MARK/SPACE parity is not supported\n");
348		}
349	} else {
350		request.params |= UPD78F0730_PARITY_NONE;
351		dev_dbg(dev, "%s - no parity\n", __func__);
352	}
353
354	if (C_CSTOPB(tty)) {
355		request.params |= UPD78F0730_STOP_BIT_2_BIT;
356		dev_dbg(dev, "%s - 2 stop bits\n", __func__);
357	} else {
358		request.params |= UPD78F0730_STOP_BIT_1_BIT;
359		dev_dbg(dev, "%s - 1 stop bit\n", __func__);
360	}
361
362	if (C_CRTSCTS(tty)) {
363		tty->termios.c_cflag &= ~CRTSCTS;
364		dev_warn(dev, "RTSCTS flow control is not supported\n");
365	}
366	if (I_IXOFF(tty) || I_IXON(tty)) {
367		tty->termios.c_iflag &= ~(IXOFF | IXON);
368		dev_warn(dev, "XON/XOFF flow control is not supported\n");
369	}
370	request.params |= UPD78F0730_FLOW_CONTROL_NONE;
371	dev_dbg(dev, "%s - no flow control\n", __func__);
372
373	upd78f0730_send_ctl(port, &request, sizeof(request));
374}
375
376static int upd78f0730_open(struct tty_struct *tty, struct usb_serial_port *port)
377{
378	static const struct upd78f0730_open_close request = {
379		.opcode = UPD78F0730_CMD_OPEN_CLOSE,
380		.state = UPD78F0730_PORT_OPEN
381	};
382	int res;
383
384	res = upd78f0730_send_ctl(port, &request, sizeof(request));
385	if (res)
386		return res;
387
388	if (tty)
389		upd78f0730_set_termios(tty, port, NULL);
390
391	return usb_serial_generic_open(tty, port);
392}
393
394static void upd78f0730_close(struct usb_serial_port *port)
395{
396	static const struct upd78f0730_open_close request = {
397		.opcode = UPD78F0730_CMD_OPEN_CLOSE,
398		.state = UPD78F0730_PORT_CLOSE
399	};
400
401	usb_serial_generic_close(port);
402	upd78f0730_send_ctl(port, &request, sizeof(request));
403}
404
405static struct usb_serial_driver upd78f0730_device = {
406	.driver	 = {
407		.owner	= THIS_MODULE,
408		.name	= "upd78f0730",
409	},
410	.id_table	= id_table,
411	.num_ports	= 1,
412	.port_probe	= upd78f0730_port_probe,
413	.port_remove	= upd78f0730_port_remove,
414	.open		= upd78f0730_open,
415	.close		= upd78f0730_close,
416	.set_termios	= upd78f0730_set_termios,
417	.tiocmget	= upd78f0730_tiocmget,
418	.tiocmset	= upd78f0730_tiocmset,
419	.dtr_rts	= upd78f0730_dtr_rts,
420	.break_ctl	= upd78f0730_break_ctl,
421};
422
423static struct usb_serial_driver * const serial_drivers[] = {
424	&upd78f0730_device,
425	NULL
426};
427
428module_usb_serial_driver(serial_drivers, id_table);
429
430MODULE_DESCRIPTION(DRIVER_DESC);
431MODULE_AUTHOR(DRIVER_AUTHOR);
432MODULE_LICENSE("GPL v2");