USB: serial: add uPD78F0730 USB to Serial Adaptor Driver
authorMaksim Salau <maksim.salau@gmail.com>
Wed, 25 Jan 2017 20:40:40 +0000 (23:40 +0300)
committerJohan Hovold <johan@kernel.org>
Thu, 26 Jan 2017 09:18:17 +0000 (10:18 +0100)
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>
drivers/usb/serial/Kconfig
drivers/usb/serial/Makefile
drivers/usb/serial/upd78f0730.c [new file with mode: 0644]

index d9bc8dafe000c84732e19c4a7530ab150c1f23fc..a8d5f2e4878dcaee2fe50470d22028ba8c6a3506 100644 (file)
@@ -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
index 9e43b7b002eba7dc7c98c81919e0889f4be8b877..5a21a82390e1326fa4883a48f68db361efb3995b 100644 (file)
@@ -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
diff --git a/drivers/usb/serial/upd78f0730.c b/drivers/usb/serial/upd78f0730.c
new file mode 100644 (file)
index 0000000..55b9a18
--- /dev/null
@@ -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");