diff options
| -rw-r--r-- | drivers/usb/serial/ark3116.c | 188 |
1 files changed, 182 insertions, 6 deletions
diff --git a/drivers/usb/serial/ark3116.c b/drivers/usb/serial/ark3116.c index 131e61adaaf7..5c947410c857 100644 --- a/drivers/usb/serial/ark3116.c +++ b/drivers/usb/serial/ark3116.c @@ -1,4 +1,6 @@ /* + * Copyright (C) 2009 by Bart Hartgers (bart.hartgers+ark3116@gmail.com) + * Original version: * Copyright (C) 2006 * Simon Schulz (ark3116_driver <at> auctionant.de) * @@ -6,10 +8,13 @@ * - implements a driver for the arkmicro ark3116 chipset (vendor=0x6547, * productid=0x0232) (used in a datacable called KQ-U8A) * - * - based on code by krisfx -> thanks !! - * (see http://www.linuxquestions.org/questions/showthread.php?p=2184457#post2184457) + * Supports full modem status lines, break, hardware flow control. Does not + * support software flow control, since I do not know how to enable it in hw. * - * - based on logs created by usbsnoopy + * This driver is a essentially new implementation. I initially dug + * into the old ark3116.c driver and suddenly realized the ark3116 is + * a 16450 with a USB interface glued to it. See comments at the + * bottom of this file. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the @@ -19,15 +24,31 @@ #include <linux/kernel.h> #include <linux/init.h> +#include <linux/ioctl.h> #include <linux/tty.h> +#include <linux/tty_flip.h> #include <linux/module.h> #include <linux/usb.h> #include <linux/usb/serial.h> #include <linux/serial.h> +#include <linux/serial_reg.h> #include <linux/uaccess.h> - +#include <linux/mutex.h> +#include <linux/spinlock.h> static int debug; +/* + * Version information + */ + +#define DRIVER_VERSION "v0.5" +#define DRIVER_AUTHOR "Bart Hartgers <bart.hartgers+ark3116@gmail.com>" +#define DRIVER_DESC "USB ARK3116 serial/IrDA driver" +#define DRIVER_DEV_DESC "ARK3116 RS232/IrDA" +#define DRIVER_NAME "ark3116" + +/* usb timeout of 1 second */ +#define ARK_TIMEOUT (1*HZ) static struct usb_device_id id_table [] = { { USB_DEVICE(0x6547, 0x0232) }, @@ -45,6 +66,53 @@ static int is_irda(struct usb_serial *serial) return 0; } +struct ark3116_private { + wait_queue_head_t delta_msr_wait; + struct async_icount icount; + int irda; /* 1 for irda device */ + + /* protects hw register updates */ + struct mutex hw_lock; + + int quot; /* baudrate divisor */ + __u32 lcr; /* line control register value */ + __u32 hcr; /* handshake control register (0x8) + * value */ + __u32 mcr; /* modem contol register value */ + + /* protects the status values below */ + spinlock_t status_lock; + __u32 msr; /* modem status register value */ + __u32 lsr; /* line status register value */ +}; + +static int ark3116_write_reg(struct usb_serial *serial, + unsigned reg, __u8 val) +{ + int result; + /* 0xfe 0x40 are magic values taken from original driver */ + result = usb_control_msg(serial->dev, + usb_sndctrlpipe(serial->dev, 0), + 0xfe, 0x40, val, reg, + NULL, 0, ARK_TIMEOUT); + return result; +} + +static int ark3116_read_reg(struct usb_serial *serial, + unsigned reg, unsigned char *buf) +{ + int result; + /* 0xfe 0xc0 are magic values taken from original driver */ + result = usb_control_msg(serial->dev, + usb_rcvctrlpipe(serial->dev, 0), + 0xfe, 0xc0, 0, reg, + buf, 1, ARK_TIMEOUT); + if (result < 0) + return result; + else + return buf[0]; +} + static inline void ARK3116_SND(struct usb_serial *serial, int seq, __u8 request, __u8 requesttype, __u16 value, __u16 index) @@ -465,7 +533,12 @@ static int __init ark3116_init(void) if (retval) return retval; retval = usb_register(&ark3116_driver); - if (retval) + if (retval == 0) { + printk(KERN_INFO "%s:" + DRIVER_VERSION ":" + DRIVER_DESC "\n", + KBUILD_MODNAME); + } else usb_serial_deregister(&ark3116_device); return retval; } @@ -480,6 +553,109 @@ module_init(ark3116_init); module_exit(ark3116_exit); MODULE_LICENSE("GPL"); +MODULE_AUTHOR(DRIVER_AUTHOR); +MODULE_DESCRIPTION(DRIVER_DESC); + module_param(debug, bool, S_IRUGO | S_IWUSR); -MODULE_PARM_DESC(debug, "Debug enabled or not"); +MODULE_PARM_DESC(debug, "Enable debug"); +/* + * The following describes what I learned from studying the old + * ark3116.c driver, disassembling the windows driver, and some lucky + * guesses. Since I do not have any datasheet or other + * documentation, inaccuracies are almost guaranteed. + * + * Some specs for the ARK3116 can be found here: + * http://web.archive.org/web/20060318000438/ + * www.arkmicro.com/en/products/view.php?id=10 + * On that page, 2 GPIO pins are mentioned: I assume these are the + * OUT1 and OUT2 pins of the UART, so I added support for those + * through the MCR. Since the pins are not available on my hardware, + * I could not verify this. + * Also, it states there is "on-chip hardware flow control". I have + * discovered how to enable that. Unfortunately, I do not know how to + * enable XON/XOFF (software) flow control, which would need support + * from the chip as well to work. Because of the wording on the web + * page there is a real possibility the chip simply does not support + * software flow control. + * + * I got my ark3116 as part of a mobile phone adapter cable. On the + * PCB, the following numbered contacts are present: + * + * 1:- +5V + * 2:o DTR + * 3:i RX + * 4:i DCD + * 5:o RTS + * 6:o TX + * 7:i RI + * 8:i DSR + * 10:- 0V + * 11:i CTS + * + * On my chip, all signals seem to be 3.3V, but 5V tolerant. But that + * may be different for the one you have ;-). + * + * The windows driver limits the registers to 0-F, so I assume there + * are actually 16 present on the device. + * + * On an UART interrupt, 4 bytes of data come in on the interrupt + * endpoint. The bytes are 0xe8 IIR LSR MSR. + * + * The baudrate seems to be generated from the 12MHz crystal, using + * 4-times subsampling. So quot=12e6/(4*baud). Also see description + * of register E. + * + * Registers 0-7: + * These seem to be the same as for a regular 16450. The FCR is set + * to UART_FCR_DMA_SELECT (0x8), I guess to enable transfers between + * the UART and the USB bridge/DMA engine. + * + * Register 8: + * By trial and error, I found out that bit 0 enables hardware CTS, + * stopping TX when CTS is +5V. Bit 1 does the same for RTS, making + * RTS +5V when the 3116 cannot transfer the data to the USB bus + * (verified by disabling the reading URB). Note that as far as I can + * tell, the windows driver does NOT use this, so there might be some + * hardware bug or something. + * + * According to a patch provided here + * (http://lkml.org/lkml/2009/7/26/56), the ARK3116 can also be used + * as an IrDA dongle. Since I do not have such a thing, I could not + * investigate that aspect. However, I can speculate ;-). + * + * - IrDA encodes data differently than RS232. Most likely, one of + * the bits in registers 9..E enables the IR ENDEC (encoder/decoder). + * - Depending on the IR transceiver, the input and output need to be + * inverted, so there are probably bits for that as well. + * - IrDA is half-duplex, so there should be a bit for selecting that. + * + * This still leaves at least two registers unaccounted for. Perhaps + * The chip can do XON/XOFF or CRC in HW? + * + * Register 9: + * Set to 0x00 for IrDA, when the baudrate is initialised. + * + * Register A: + * Set to 0x01 for IrDA, at init. + * + * Register B: + * Set to 0x01 for IrDA, 0x00 for RS232, at init. + * + * Register C: + * Set to 00 for IrDA, at init. + * + * Register D: + * Set to 0x41 for IrDA, at init. + * + * Register E: + * Somekind of baudrate override. The windows driver seems to set + * this to 0x00 for normal baudrates, 0x01 for 460800, 0x02 for 921600. + * Since 460800 and 921600 cannot be obtained by dividing 3MHz by an integer, + * it could be somekind of subdivisor thingy. + * However,it does not seem to do anything: selecting 921600 (divisor 3, + * reg E=2), still gets 1 MHz. I also checked if registers 9, C or F would + * work, but they don't. + * + * Register F: unknown + */ |
