usb:serial:f81534 add F81532/534 driver

This driver is for Fintek F81532/F81534 USB to Serial Ports IC.

Features:
1. F81534 is 1-to-4 & F81532 is 1-to-2 serial ports IC
2. Support Baudrate from B50 to B1500000 (excluding B1000000).
3. The RTS signal can be transformed their behavior with configuration by default ioctl TIOCGRS485/TIOCSRS485 (for RS232/RS485/RS422 with transceiver)

If the driver setting with SER_RS485_ENABLED, the RTS signal will high with not in TX and low with in TX.

If the driver setting with SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND, the RTS signal will low with not in TX and high with in TX.

4. There are 4x3 output-only ic pins to control transceiver mode. It's can be controlled via gpiolib. We could found the gpio number from /sys/class/tty/ttyUSB[x]/device/gpiochap[yyy] where x is F81532/534 serial port and yyy is gpiochip number.

After we found chip number, we can export 3 gpios(M2/M1/M0) per serial port by
echo yyy > /sys/class/gpio/export
echo yyy+1 > /sys/class/gpio/export
echo yyy+2 > /sys/class/gpio/export

then we can control it with

      echo [M0 value] > /sys/class/gpio/gpio[yyy]/value
      echo [M1 value] > /sys/class/gpio/gpio[yyy+1]/value
      echo [M2 value] > /sys/class/gpio/gpio[yyy+2]/value

which M0/M1/M2 as your desired value, value is only 0 or 1.

When configure complete, It's a must to free all gpio by
echo yyy > /sys/class/gpio/unexport
echo yyy+1 > /sys/class/gpio/unexport
echo yyy+2 > /sys/class/gpio/unexport

The driver will "save" gpio configure after we release all gpio of a serial port.

For examples to change mode & gpio with F81532/534 Evalaution Board.

F81532 EVB

      port0: F81437 (RS232 only)
      port1: F81439 (RS232/RS485/RS422 ... etc.)

F81534 EVB
port0/1: F81437 (RS232 only) port2/3: F81439 (RS232/RS485/RS422 ... etc.)

1. RS232 Mode (Default IC Mode)
1. Set struct serial_rs485 flags "without" SER_RS485_ENABLED (control F81532/534 RTS control)
2. Set M2/M1/M0 as 0/0/1
(control F81532/534 output pin to control transceiver mode)

2. RS485 Mode (RTS Low when TX Mode)
1. Set struct serial_rs485 flags with SER_RS485_ENABLED
2. Set M2/M1/M0 as 0/1/0

3. RS485 Mode (RTS High when TX Mode)
1. Set struct serial_rs485 flags with SER_RS485_ENABLED and SER_RS485_RTS_ON_SEND
2. Set M2/M1/M0 as 0/1/1

4. RS422 Mode
1. The RTS mode is dont care.
2. Set M2/M1/M0 as 0/0/0

Please reference https://bitbucket.org/hpeter/fintek-general/src/
with f81534/tools to get set_gpio.c & set_mode.c. Please use it carefully.

Changelog
v4
1. clearify f81534_process_read_urb() with f81534_process_per_serial_block(). (referenced from mxuport.c)
2. We limited f81534_write() max tx kfifo with 124Bytes. Original subsystem is designed for auto tranmiting fifo data if available. But we must wait for tx_empty for next tx data (H/W design).

With this kfifo size limit, we can use generic subsystem api with f81534_write(). When usb_serial_generic_write_start() called after first write URB complete, the fifo will no data. The generic subsystem of write will go to idle state. Until we received TX_EMPTY and release write spinlock, the fifo will fill max 124Bytes by following f81534_write().

v3
1. Migrate read, write and some routine from custom code to usbserial subsystem callback function.
2. Use more defines to replece magic numbers to make it meaningful
3. Make more comments as document in source code.

v2
1. v1 version submit to staging tree, but Greg KH advised me to cleanup source code & re-submit it to correct subsystem
2. Remove all custom ioctl commands

---
 drivers/usb/serial/Kconfig  |   10 +
 drivers/usb/serial/Makefile |    1 +
 drivers/usb/serial/f81534.c | 3315 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 3326 insertions(+)
 create mode 100644 drivers/usb/serial/f81534.c

index 56ecb8b..0642864 100644
@@ -255,6 +255,16 @@ config USB_SERIAL_F81232
 	  To compile this driver as a module, choose M here: the
 	  module will be called f81232.
 
+config USB_SERIAL_F8153X
+	tristate "USB Fintek F81532/534 Multi-Ports Serial Driver"
+	help
+	  Say Y here if you want to use the Fintek F81532/534 Multi-Ports
+	  usb to serial adapter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called f81534.
+
+
 config USB_SERIAL_GARMIN
        tristate "USB Garmin GPS driver"
        help

index 349d9df..9e43b7b 100644
@@ -23,6 +23,7 @@ obj-$(CONFIG_USB_SERIAL_EDGEPORT)		+= io_edgeport.o
 obj-$(CONFIG_USB_SERIAL_EDGEPORT_TI)		+= io_ti.o
 obj-$(CONFIG_USB_SERIAL_EMPEG)			+= empeg.o
 obj-$(CONFIG_USB_SERIAL_F81232)			+= f81232.o
+obj-$(CONFIG_USB_SERIAL_F8153X)			+= f81534.o
 obj-$(CONFIG_USB_SERIAL_FTDI_SIO)		+= ftdi_sio.o
 obj-$(CONFIG_USB_SERIAL_GARMIN)			+= garmin_gps.o
 obj-$(CONFIG_USB_SERIAL_IPAQ)			+= ipaq.o

1.9.1

Part of the diff is not shown here. View the raw message.

Just a few nits, I'm afraid.

and add an empty line here, things look neater.

Hi Paul & Johan

Paul Bolle 於 2015/7/15 下午 04:36 寫道:

Thanks Paul for point this out.

And sorry for Johan. It's seems to make a new patch V5. I'll merge some minor fix with newer patch.

With Best Regards,
Peter Hung

No problem, I'll wait for v5.

Thanks,
Johan