Commit ea534e0b authored by Maksim Salau's avatar Maksim Salau Committed by Johan Hovold
Browse files

USB: serial: add uPD78F0730 USB to Serial Adaptor Driver 



The adaptor can be found on development boards for 78k, RL78 and V850
microcontrollers produced by Renesas Electronics Corporation.

This is not a full-featured USB to serial converter, however it allows
basic communication and simple control which is enough for programming of
on-board flash and debugging through a debug monitor.

uPD78F0730 is a USB-enabled microcontroller with USB-to-UART conversion
implemented in firmware.

This chip is also present in some debugging adaptors which use it for
USB-to-SPI conversion as well. The present driver doesn't cover SPI,
only USB-to-UART conversion is supported.

Signed-off-by: default avatarMaksim Salau <maksim.salau@gmail.com>
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
parent 51211a3d

drivers/usb/serial/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -713,6 +713,15 @@ config USB_SERIAL_QT2 
	  To compile this driver as a module, choose M here: the

	  module will be called quatech-serial.



config USB_SERIAL_UPD78F0730

	tristate "USB Renesas uPD78F0730 Single Port Serial Driver"

	help

	  Say Y here if you want to use the Renesas uPD78F0730

	  serial driver.



	  To compile this driver as a module, choose M here: the

	  module will be called upd78f0730.



config USB_SERIAL_DEBUG

	tristate "USB Debugging Device"

	help

drivers/usb/serial/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ obj-$(CONFIG_USB_SERIAL_SSU100) += ssu100.o 
obj-$(CONFIG_USB_SERIAL_SYMBOL)			+= symbolserial.o

obj-$(CONFIG_USB_SERIAL_WWAN)			+= usb_wwan.o

obj-$(CONFIG_USB_SERIAL_TI)			+= ti_usb_3410_5052.o

obj-$(CONFIG_USB_SERIAL_UPD78F0730)		+= upd78f0730.o

obj-$(CONFIG_USB_SERIAL_VISOR)			+= visor.o

obj-$(CONFIG_USB_SERIAL_WISHBONE)		+= wishbone-serial.o

obj-$(CONFIG_USB_SERIAL_WHITEHEAT)		+= whiteheat.o

drivers/usb/serial/upd78f0730.c

0 → 100644
+440 −0
Original line number Diff line number Diff line 
/*

 * Renesas Electronics uPD78F0730 USB to serial converter driver

 *

 * Copyright (C) 2014,2016 Maksim Salau <maksim.salau@gmail.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2

 * as published by the Free Software Foundation.

 *

 * Protocol of the adaptor is described in the application note U19660EJ1V0AN00

 * μPD78F0730 8-bit Single-Chip Microcontroller

 * USB-to-Serial Conversion Software

 * <https://www.renesas.com/en-eu/doc/DocumentServer/026/U19660EJ1V0AN00.pdf>

 *

 * The adaptor functionality is limited to the following:

 * - data bits: 7 or 8

 * - stop bits: 1 or 2

 * - parity: even, odd or none

 * - flow control: none

 * - baud rates: 0, 2400, 4800, 9600, 19200, 38400, 57600, 115200

 * - signals: DTR, RTS and BREAK

 */



#include <linux/module.h>

#include <linux/slab.h>

#include <linux/tty.h>

#include <linux/usb.h>

#include <linux/usb/serial.h>



#define DRIVER_DESC "Renesas uPD78F0730 USB to serial converter driver"



#define DRIVER_AUTHOR "Maksim Salau <maksim.salau@gmail.com>"



static const struct usb_device_id id_table[] = {

	{ USB_DEVICE(0x045B, 0x0212) }, /* YRPBRL78G13, YRPBRL78G14 */

	{ USB_DEVICE(0x0409, 0x0063) }, /* V850ESJX3-STICK */

	{}

};



MODULE_DEVICE_TABLE(usb, id_table);



/*

 * Each adaptor is associated with a private structure, that holds the current

 * state of control signals (DTR, RTS and BREAK).

 */

struct upd78f0730_port_private {

	struct mutex	lock;		/* mutex to protect line_signals */

	u8		line_signals;

};



/* Op-codes of control commands */

#define UPD78F0730_CMD_LINE_CONTROL	0x00

#define UPD78F0730_CMD_SET_DTR_RTS	0x01

#define UPD78F0730_CMD_SET_XON_XOFF_CHR	0x02

#define UPD78F0730_CMD_OPEN_CLOSE	0x03

#define UPD78F0730_CMD_SET_ERR_CHR	0x04



/* Data sizes in UPD78F0730_CMD_LINE_CONTROL command */

#define UPD78F0730_DATA_SIZE_7_BITS	0x00

#define UPD78F0730_DATA_SIZE_8_BITS	0x01

#define UPD78F0730_DATA_SIZE_MASK	0x01



/* Stop-bit modes in UPD78F0730_CMD_LINE_CONTROL command */

#define UPD78F0730_STOP_BIT_1_BIT	0x00

#define UPD78F0730_STOP_BIT_2_BIT	0x02

#define UPD78F0730_STOP_BIT_MASK	0x02



/* Parity modes in UPD78F0730_CMD_LINE_CONTROL command */

#define UPD78F0730_PARITY_NONE	0x00

#define UPD78F0730_PARITY_EVEN	0x04

#define UPD78F0730_PARITY_ODD	0x08

#define UPD78F0730_PARITY_MASK	0x0C



/* Flow control modes in UPD78F0730_CMD_LINE_CONTROL command */

#define UPD78F0730_FLOW_CONTROL_NONE	0x00

#define UPD78F0730_FLOW_CONTROL_HW	0x10

#define UPD78F0730_FLOW_CONTROL_SW	0x20

#define UPD78F0730_FLOW_CONTROL_MASK	0x30



/* Control signal bits in UPD78F0730_CMD_SET_DTR_RTS command */

#define UPD78F0730_RTS		0x01

#define UPD78F0730_DTR		0x02

#define UPD78F0730_BREAK	0x04



/* Port modes in UPD78F0730_CMD_OPEN_CLOSE command */

#define UPD78F0730_PORT_CLOSE	0x00

#define UPD78F0730_PORT_OPEN	0x01



/* Error character substitution modes in UPD78F0730_CMD_SET_ERR_CHR command */

#define UPD78F0730_ERR_CHR_DISABLED	0x00

#define UPD78F0730_ERR_CHR_ENABLED	0x01



/*

 * Declaration of command structures

 */



/* UPD78F0730_CMD_LINE_CONTROL command */

struct upd78f0730_line_control {

	u8	opcode;

	__le32	baud_rate;

	u8	params;

} __packed;



/* UPD78F0730_CMD_SET_DTR_RTS command */

struct upd78f0730_set_dtr_rts {

	u8 opcode;

	u8 params;

};



/* UPD78F0730_CMD_SET_XON_OFF_CHR command */

struct upd78f0730_set_xon_xoff_chr {

	u8 opcode;

	u8 xon;

	u8 xoff;

};



/* UPD78F0730_CMD_OPEN_CLOSE command */

struct upd78f0730_open_close {

	u8 opcode;

	u8 state;

};



/* UPD78F0730_CMD_SET_ERR_CHR command */

struct upd78f0730_set_err_chr {

	u8 opcode;

	u8 state;

	u8 err_char;

};



static int upd78f0730_send_ctl(struct usb_serial_port *port,

			const void *data, int size)

{

	struct usb_device *usbdev = port->serial->dev;

	void *buf;

	int res;



	if (size <= 0 || !data)

		return -EINVAL;



	buf = kmemdup(data, size, GFP_KERNEL);

	if (!buf)

		return -ENOMEM;



	res = usb_control_msg(usbdev, usb_sndctrlpipe(usbdev, 0), 0x00,

			USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,

			0x0000, 0x0000, buf, size, USB_CTRL_SET_TIMEOUT);



	kfree(buf);



	if (res != size) {

		struct device *dev = &port->dev;



		dev_err(dev, "failed to send control request %02x: %d\n",

			*(u8 *)data, res);

		/* The maximum expected length of a transfer is 6 bytes */

		if (res >= 0)

			res = -EIO;



		return res;

	}



	return 0;

}



static int upd78f0730_port_probe(struct usb_serial_port *port)

{

	struct upd78f0730_port_private *private;



	private = kzalloc(sizeof(*private), GFP_KERNEL);

	if (!private)

		return -ENOMEM;



	mutex_init(&private->lock);

	usb_set_serial_port_data(port, private);



	return 0;

}



static int upd78f0730_port_remove(struct usb_serial_port *port)

{

	struct upd78f0730_port_private *private;



	private = usb_get_serial_port_data(port);

	mutex_destroy(&private->lock);

	kfree(private);



	return 0;

}



static int upd78f0730_tiocmget(struct tty_struct *tty)

{

	struct device *dev = tty->dev;

	struct upd78f0730_port_private *private;

	struct usb_serial_port *port = tty->driver_data;

	int signals;

	int res;



	private = usb_get_serial_port_data(port);



	mutex_lock(&private->lock);

	signals = private->line_signals;

	mutex_unlock(&private->lock);



	res = ((signals & UPD78F0730_DTR) ? TIOCM_DTR : 0) |

		((signals & UPD78F0730_RTS) ? TIOCM_RTS : 0);



	dev_dbg(dev, "%s - res = %x\n", __func__, res);



	return res;

}



static int upd78f0730_tiocmset(struct tty_struct *tty,

			unsigned int set, unsigned int clear)

{

	struct device *dev = tty->dev;

	struct usb_serial_port *port = tty->driver_data;

	struct upd78f0730_port_private *private;

	struct upd78f0730_set_dtr_rts request;

	int res;



	private = usb_get_serial_port_data(port);



	mutex_lock(&private->lock);

	if (set & TIOCM_DTR) {

		private->line_signals |= UPD78F0730_DTR;

		dev_dbg(dev, "%s - set DTR\n", __func__);

	}

	if (set & TIOCM_RTS) {

		private->line_signals |= UPD78F0730_RTS;

		dev_dbg(dev, "%s - set RTS\n", __func__);

	}

	if (clear & TIOCM_DTR) {

		private->line_signals &= ~UPD78F0730_DTR;

		dev_dbg(dev, "%s - clear DTR\n", __func__);

	}

	if (clear & TIOCM_RTS) {

		private->line_signals &= ~UPD78F0730_RTS;

		dev_dbg(dev, "%s - clear RTS\n", __func__);

	}

	request.opcode = UPD78F0730_CMD_SET_DTR_RTS;

	request.params = private->line_signals;



	res = upd78f0730_send_ctl(port, &request, sizeof(request));

	mutex_unlock(&private->lock);



	return res;

}



static void upd78f0730_break_ctl(struct tty_struct *tty, int break_state)

{

	struct device *dev = tty->dev;

	struct upd78f0730_port_private *private;

	struct usb_serial_port *port = tty->driver_data;

	struct upd78f0730_set_dtr_rts request;



	private = usb_get_serial_port_data(port);



	mutex_lock(&private->lock);

	if (break_state) {

		private->line_signals |= UPD78F0730_BREAK;

		dev_dbg(dev, "%s - set BREAK\n", __func__);

	} else {

		private->line_signals &= ~UPD78F0730_BREAK;

		dev_dbg(dev, "%s - clear BREAK\n", __func__);

	}

	request.opcode = UPD78F0730_CMD_SET_DTR_RTS;

	request.params = private->line_signals;



	upd78f0730_send_ctl(port, &request, sizeof(request));

	mutex_unlock(&private->lock);

}



static void upd78f0730_dtr_rts(struct usb_serial_port *port, int on)

{

	struct tty_struct *tty = port->port.tty;

	unsigned int set = 0;

	unsigned int clear = 0;



	if (on)

		set = TIOCM_DTR | TIOCM_RTS;

	else

		clear = TIOCM_DTR | TIOCM_RTS;



	upd78f0730_tiocmset(tty, set, clear);

}



static speed_t upd78f0730_get_baud_rate(struct tty_struct *tty)

{

	const speed_t baud_rate = tty_get_baud_rate(tty);

	const speed_t supported[] = {

		0, 2400, 4800, 9600, 19200, 38400, 57600, 115200

	};

	int i;



	for (i = ARRAY_SIZE(supported) - 1; i >= 0; i--) {

		if (baud_rate == supported[i])

			return baud_rate;

	}



	/* If the baud rate is not supported, switch to the default one */

	tty_encode_baud_rate(tty, 9600, 9600);



	return tty_get_baud_rate(tty);

}



static void upd78f0730_set_termios(struct tty_struct *tty,

				struct usb_serial_port *port,

				struct ktermios *old_termios)

{

	struct device *dev = &port->dev;

	struct upd78f0730_line_control request;

	speed_t baud_rate;



	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))

		return;



	if (C_BAUD(tty) == B0)

		upd78f0730_dtr_rts(port, 0);

	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)

		upd78f0730_dtr_rts(port, 1);



	baud_rate = upd78f0730_get_baud_rate(tty);

	request.opcode = UPD78F0730_CMD_LINE_CONTROL;

	request.baud_rate = cpu_to_le32(baud_rate);

	request.params = 0;

	dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud_rate);



	switch (C_CSIZE(tty)) {

	case CS7:

		request.params |= UPD78F0730_DATA_SIZE_7_BITS;

		dev_dbg(dev, "%s - 7 data bits\n", __func__);

		break;

	default:

		tty->termios.c_cflag &= ~CSIZE;

		tty->termios.c_cflag |= CS8;

		dev_warn(dev, "data size is not supported, using 8 bits\n");

		/* fall through */

	case CS8:

		request.params |= UPD78F0730_DATA_SIZE_8_BITS;

		dev_dbg(dev, "%s - 8 data bits\n", __func__);

		break;

	}



	if (C_PARENB(tty)) {

		if (C_PARODD(tty)) {

			request.params |= UPD78F0730_PARITY_ODD;

			dev_dbg(dev, "%s - odd parity\n", __func__);

		} else {

			request.params |= UPD78F0730_PARITY_EVEN;

			dev_dbg(dev, "%s - even parity\n", __func__);

		}



		if (C_CMSPAR(tty)) {

			tty->termios.c_cflag &= ~CMSPAR;

			dev_warn(dev, "MARK/SPACE parity is not supported\n");

		}

	} else {

		request.params |= UPD78F0730_PARITY_NONE;

		dev_dbg(dev, "%s - no parity\n", __func__);

	}



	if (C_CSTOPB(tty)) {

		request.params |= UPD78F0730_STOP_BIT_2_BIT;

		dev_dbg(dev, "%s - 2 stop bits\n", __func__);

	} else {

		request.params |= UPD78F0730_STOP_BIT_1_BIT;

		dev_dbg(dev, "%s - 1 stop bit\n", __func__);

	}



	if (C_CRTSCTS(tty)) {

		tty->termios.c_cflag &= ~CRTSCTS;

		dev_warn(dev, "RTSCTS flow control is not supported\n");

	}

	if (I_IXOFF(tty) || I_IXON(tty)) {

		tty->termios.c_iflag &= ~(IXOFF | IXON);

		dev_warn(dev, "XON/XOFF flow control is not supported\n");

	}

	request.params |= UPD78F0730_FLOW_CONTROL_NONE;

	dev_dbg(dev, "%s - no flow control\n", __func__);



	upd78f0730_send_ctl(port, &request, sizeof(request));

}



static int upd78f0730_open(struct tty_struct *tty, struct usb_serial_port *port)

{

	struct upd78f0730_open_close request = {

		.opcode = UPD78F0730_CMD_OPEN_CLOSE,

		.state = UPD78F0730_PORT_OPEN

	};

	int res;



	res = upd78f0730_send_ctl(port, &request, sizeof(request));

	if (res)

		return res;



	if (tty)

		upd78f0730_set_termios(tty, port, NULL);



	return usb_serial_generic_open(tty, port);

}



static void upd78f0730_close(struct usb_serial_port *port)

{

	struct upd78f0730_open_close request = {

		.opcode = UPD78F0730_CMD_OPEN_CLOSE,

		.state = UPD78F0730_PORT_CLOSE

	};



	usb_serial_generic_close(port);

	upd78f0730_send_ctl(port, &request, sizeof(request));

}



static struct usb_serial_driver upd78f0730_device = {

	.driver	 = {

		.owner	= THIS_MODULE,

		.name	= "upd78f0730",

	},

	.id_table	= id_table,

	.num_ports	= 1,

	.port_probe	= upd78f0730_port_probe,

	.port_remove	= upd78f0730_port_remove,

	.open		= upd78f0730_open,

	.close		= upd78f0730_close,

	.set_termios	= upd78f0730_set_termios,

	.tiocmget	= upd78f0730_tiocmget,

	.tiocmset	= upd78f0730_tiocmset,

	.dtr_rts	= upd78f0730_dtr_rts,

	.break_ctl	= upd78f0730_break_ctl,

};



static struct usb_serial_driver * const serial_drivers[] = {

	&upd78f0730_device,

	NULL

};



module_usb_serial_driver(serial_drivers, id_table);



MODULE_DESCRIPTION(DRIVER_DESC);

MODULE_AUTHOR(DRIVER_AUTHOR);

MODULE_LICENSE("GPL v2");

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