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: Maksim Salau <maksim.salau@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
diff --git a/drivers/usb/serial/upd78f0730.c b/drivers/usb/serial/upd78f0730.c
new file mode 100644
index 0000000..55b9a18
--- /dev/null
+++ b/drivers/usb/serial/upd78f0730.c
@@ -0,0 +1,440 @@
+/*
+ * 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");
