[PATCH] kernel 2.5.8-pre2, tipar: parallel link cable driver for TI graphing calculators

Romain LIEVIN
2002-04-06T08:41:31Z

Hi Linus,

I sent you a patch for 2.5.8-pre1 kernel. I resubmit it for 2.5.8-pre2.

This is a new driver which uses parport for handling a parallel link cable
designed to connect a Texas Instruments graphing calculators to a
computer/workstation.

This driver has been submitted to lkml and has been approved by Alan Cox.

Regards, Romain.

==============================[ cut here ]==============================
--- linux.orig/MAINTAINERS Sat Apr 6 10:27:43 2002
+++ linux/MAINTAINERS Sat Apr 6 10:29:27 2002
@@ -1507,6 +1507,11 @@
M: jb@technologeek.org
S: Maintained

+TI PARALLEL LINK CABLE DRIVER
+P: Romain Lievin
+M: roms@lpg.ticalc.org
+S: Maintained
+
TLAN NETWORK DRIVER
P: Torben Mathiasen
M: torben.mathiasen@compaq.com
--- linux.orig/drivers/char/Config.help Mon Mar 18 21:37:13 2002
+++ linux/drivers/char/Config.help Sat Apr 6 10:29:54 2002
@@ -595,6 +595,27 @@

If unsure, say N.

+CONFIG_TIPAR
+ If you own a Texas Instruments graphing calculator and use a
+ parallel link cable, then you might be interested in this driver.
+
+ If you enable this driver, you will be able to communicate with
+ your calculator through a set of device nodes under /dev. The
+ main advantage of this driver is that you don't have to be root
+ to use this precise link cable (depending on the permissions on
+ the device nodes, though).
+
+ This code is also available as a module ( = code which can be
+ inserted in and removed from the running kernel whenever you want).
+ The module will be called tipar.o. If you want to compile it as a
+ module, say M here and read Documentation/modules.txt.
+
+ If you don't know what a parallel link cable is or what a Texas
+ Instruments graphing calculator is, then you probably don't need this
+ driver.
+
+ If unsure, say N.
+
CONFIG_BUSMOUSE
Say Y here if your machine has a bus mouse as opposed to a serial
mouse. Most people have a regular serial MouseSystem or
--- linux.orig/drivers/char/Config.in Mon Mar 18 21:37:08 2002
+++ linux/drivers/char/Config.in Sat Apr 6 10:30:21 2002
@@ -103,6 +103,7 @@
bool ' Support for console on line printer' CONFIG_LP_CONSOLE
fi
dep_tristate 'Support for user-space parallel port device drivers' CONFIG_PPDEV $CONFIG_PARPORT
+ dep_tristate 'Texas Instruments parallel link cable support' CONFIG_TIPAR $CONFIG_PARPORT
fi

source drivers/i2c/Config.in
--- linux.orig/drivers/char/Makefile Sat Apr 6 10:31:06 2002
+++ linux/drivers/char/Makefile Sat Apr 6 10:31:22 2002
@@ -208,6 +208,7 @@
obj-$(CONFIG_DZ) += dz.o
obj-$(CONFIG_NWBUTTON) += nwbutton.o
obj-$(CONFIG_NWFLASH) += nwflash.o
+obj-$(CONFIG_TIPAR) += tipar.o

# Only one watchdog can succeed. We probe the hardware watchdog
# drivers first, then the softdog driver. This means if your hardware
--- linux.orig/drivers/char/tipar.c Sat Apr 6 10:32:06 2002
+++ linux/drivers/char/tipar.c Sat Apr 6 10:31:41 2002
@@ -0,0 +1,519 @@
+/* Hey EMACS -*- linux-c -*-
+ *
+ * tipar - low level driver for handling a parallel link cable designed
+ * for Texas Instruments graphing calculators (http://lpg.ticalc.org).
+ *
+ * Copyright (C) 2000-2002, Romain Lievin <roms@lpg.ticalc.org>
+ * under the terms of the GNU General Public License.
+ *
+ * Various fixes & clean-up from the Linux Kernel Mailing List
+ * (Alan Cox, Richard B. Johnson, Christoph Hellwig).
+ */
+
+/* This driver should, in theory, work with any parallel port that has an
+ * appropriate low-level driver; all I/O is done through the parport
+ * abstraction layer.
+ *
+ * If this driver is built into the kernel, you can configure it using the
+ * kernel command-line. For example:
+ *
+ * tipar=timeout,delay (set timeout and delay)
+ *
+ * If the driver is loaded as a module, similar functionality is available
+ * using module parameters. The equivalent of the above commands would be:
+ *
+ * # insmod tipar timeout=15 delay=10
+ */
+
+/* COMPATIBILITY WITH OLD KERNELS
+ *
+ * Usually, parallel cables were bound to ports at
+ * particular I/O addresses, as follows:
+ *
+ * tipar0 0x378
+ * tipar1 0x278
+ * tipar2 0x3bc
+ *
+ *
+ * This driver, by default, binds tipar devices according to parport and
+ * the minor number.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/fcntl.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+#include <linux/ioport.h>
+#include <asm/io.h>
+#include <asm/bitops.h>
+#include <linux/devfs_fs_kernel.h> /* DevFs support */
+#include <linux/parport.h> /* Our code depend on parport */
+
+/*
+ * TI definitions
+ */
+#include "ticable.h" //#include <linux/ticable.h>
+
+/*
+ * Version Information
+ */
+#define DRIVER_VERSION "1.15"
+#define DRIVER_AUTHOR "Romain Lievin <roms@lpg.ticalc.org>"
+#define DRIVER_DESC "Device driver for TI/PC parallel link cables"
+#define DRIVER_LICENSE "GPL"
+
+#define VERSION(ver,rel,seq) (((ver)<<16) | ((rel)<<8) | (seq))
+#if LINUX_VERSION_CODE < VERSION(2,5,0)
+# define minor(x) MINOR(x)
+# define need_resched() (current->need_resched)
+#endif
+
+/* ----- global variables --------------------------------------------- */
+
+struct tipar_struct {
+ struct pardevice *dev; /* Parport device entry */
+};
+
+#define PP_NO 3
+static struct tipar_struct table[PP_NO];
+
+static int delay = IO_DELAY; /* inter-bit delay in microseconds */
+static int timeout = TIMAXTIME; /* timeout in tenth of seconds */
+
+static devfs_handle_t devfs_handle;
+static unsigned int tp_count; /* tipar count */
+static unsigned long opened; /* opened devices */
+
+/* --- macros for parport access -------------------------------------- */
+
+#define r_dtr(x) (parport_read_data(table[(x)].dev->port))
+#define r_str(x) (parport_read_status(table[(x)].dev->port))
+#define w_ctr(x,y) (parport_write_control(table[(x)].dev->port, (y)))
+#define w_dtr(x,y) (parport_write_data(table[(x)].dev->port, (y)))
+
+/* --- setting states on the D-bus with the right timing: ------------- */
+
+static inline void outbyte(int value, int minor)
+{
+ w_dtr(minor, value);
+}
+
+static inline int inbyte(int minor)
+{
+ return (r_str(minor));
+}
+
+static inline void init_ti_parallel(int minor)
+{
+ outbyte(3, minor);
+}
+
+/* ----- global defines ----------------------------------------------- */
+
+#define START(x) { x=jiffies+HZ/(timeout/10); }
+#define WAIT(x) { \
+ if (time_before((x), jiffies)) return -1; \
+ if (need_resched()) schedule(); }
+
+/* ----- D-bus bit-banging functions ---------------------------------- */
+
+/* D-bus protocol (45kbit/s max):
+ 1 0 0
+ _______ ______|______ __________|________ __________
+Red : ________ | ____ | ____
+ _ ____________|________ ______|__________ _____
+White: ________ | ______ | _______
+*/
+
+/* Try to transmit a byte on the specified port (-1 if error). */
+static int put_ti_parallel(int minor, unsigned char data)
+{
+ int bit;
+ unsigned long max;
+
+ for (bit=0; bit<8; bit++) {
+ if (data & 1) {
+ outbyte(2, minor);
+ START(max);
+ do {
+ WAIT(max);
+ } while (inbyte(minor) & 0x10);
+
+ outbyte(3, minor);
+ START(max);
+ do {
+ WAIT(max);
+ } while (!(inbyte(minor) & 0x10));
+ } else {
+ outbyte(1, minor);
+ START(max);
+ do {
+ WAIT(max);
+ } while (inbyte(minor) & 0x20);
+
+ outbyte(3, minor);
+ START(max);
+ do {
+ WAIT(max);
+ } while (!(inbyte(minor) & 0x20));
+ }
+
+ data >>= 1;
+ udelay(delay);
+
+ if(need_resched())
+ schedule();
+ }
+
+ return 0;
+}
+
+/* Receive a byte on the specified port or -1 if error. */
+static int get_ti_parallel(int minor)
+{
+ int bit;
+ unsigned char v, data=0;
+ unsigned long max;
+
+ for (bit=0; bit<8; bit++) {
+ START(max);
+ do {
+ WAIT(max);
+ } while ((v=inbyte(minor) & 0x30) == 0x30);
+
+ if (v == 0x10) {
+ data=(data>>1) | 0x80;
+ outbyte(1, minor);
+ START(max);
+ do {
+ WAIT(max);
+ } while (!(inbyte(minor) & 0x20));
+ outbyte(3, minor);
+ } else {
+ data=data>>1;
+ outbyte(2, minor);
+ START(max);
+ do {
+ WAIT(max);
+ } while (!(inbyte(minor) & 0x10));
+ outbyte(3, minor);
+ }
+
+ udelay(delay);
+ if(need_resched())
+ schedule();
+ }
+
+ return (int)data;
+}
+
+/* Try to detect a parallel link cable on the specified port */
+static int probe_ti_parallel(int minor)
+{
+ int i;
+ int seq[]={ 0x00, 0x20, 0x10, 0x30 };
+
+ for(i=3; i>=0; i--) {
+ outbyte(3, minor);
+ outbyte(i, minor);
+ udelay(delay);
+ /*printk(KERN_DEBUG "Probing -> %i: 0x%02x 0x%02x\n", i, data & 0x30, seq[i]);*/
+ if ( (inbyte(minor) & 0x30) != seq[i]) {
+ outbyte(3, minor);
+ return -1;
+ }
+ }
+ outbyte(3, minor);
+ return 0;
+}
+
+/* ----- kernel module functions--------------------------------------- */
+
+static int tipar_open(struct inode *inode, struct file *file)
+{
+ unsigned int minor = minor(inode->i_rdev) - TIPAR_MINOR;
+
+ if (minor > tp_count-1)
+ return -ENXIO;
+
+ if(test_and_set_bit(minor, &opened))
+ return -EBUSY;
+
+ parport_claim_or_block (table[minor].dev);
+ init_ti_parallel (minor);
+ parport_release (table[minor].dev);
+
+ return 0;
+}
+
+static int tipar_close(struct inode *inode, struct file *file)
+{
+ unsigned int minor = minor(inode->i_rdev) - TIPAR_MINOR;
+
+ if (minor > tp_count-1)
+ return -ENXIO;
+
+ clear_bit(minor, &opened);
+
+ return 0;
+}
+
+static ssize_t tipar_write(struct file *file,
+ const char *buf, size_t count, loff_t *ppos)
+{
+ unsigned int minor=minor(file->f_dentry->d_inode->i_rdev)-TIPAR_MINOR;
+ ssize_t n;
+
+ parport_claim_or_block (table[minor].dev);
+
+ for(n=0; n<count; n++) {
+ unsigned char b;
+
+ if (get_user(b, buf + n)) {
+ n = -EFAULT;
+ goto out;
+ }
+
+ if (put_ti_parallel(minor, b) == -1) {
+ init_ti_parallel(minor);
+ n = -ETIMEDOUT;
+ goto out;
+ }
+ }
+ out:
+ parport_release (table[minor].dev);
+ return n;
+}
+
+static ssize_t tipar_read(struct file *file, char *buf,
+ size_t count, loff_t *ppos)
+{
+ int b=0;
+ unsigned int minor=minor(file->f_dentry->d_inode->i_rdev)-TIPAR_MINOR;
+ ssize_t retval = 0;
+ ssize_t n = 0;
+
+ if (count == 0)
+ return 0;
+
+ if (ppos != &file->f_pos)
+ return -ESPIPE;
+
+ parport_claim_or_block(table[minor].dev);
+
+ while(n < count) {
+ b = get_ti_parallel(minor);
+ if (b == -1) {
+ init_ti_parallel(minor);
+ retval = -ETIMEDOUT;
+ goto out;
+ }
+ else {
+ if(put_user(b, ((unsigned char *)buf)+n)) {
+ retval = -EFAULT;
+ break;
+ } else retval = n;
+ }
+
+ /* Non-blocking mode: try again ! */
+ if (file->f_flags & O_NONBLOCK) {
+ retval = -EAGAIN;
+ goto out;
+ }
+
+ /* Signal pending, try again ! */
+ if (signal_pending(current)) {
+ retval = -ERESTARTSYS;
+ goto out;
+ }
+
+ n++;
+ if(need_resched())
+ schedule();
+ }
+
+ out:
+ parport_release(table[minor].dev);
+ return retval;
+}
+
+static int tipar_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int retval = 0;
+
+ switch (cmd) {
+ case IOCTL_TIPAR_DELAY:
+ get_user(delay, &arg);
+ break;
+ case IOCTL_TIPAR_TIMEOUT:
+ get_user(timeout, &arg);
+ break;
+ default:
+ retval = -ENOTTY;
+ break;
+ }
+
+ return retval;
+}
+
+/* ----- kernel module registering ------------------------------------ */
+
+static struct file_operations tipar_fops = {
+ owner: THIS_MODULE,
+ llseek: no_llseek,
+ read: tipar_read,
+ write: tipar_write,
+ ioctl: tipar_ioctl,
+ open: tipar_open,
+ release: tipar_close,
+};
+
+/* --- initialisation code ------------------------------------- */
+
+#ifndef MODULE
+/* You must set these - there is no sane way to probe for this cable.
+ * You can use 'tipar=timeout,delay' to set these now. */
+static int __init tipar_setup (char *str)
+{
+ int ints[2];
+
+ str = get_options (str, ARRAY_SIZE(ints), ints);
+
+ if (ints[0] > 0) {
+ timeout = ints[1];
+ if (ints[0] > 1) {
+ delay = ints[2];
+ }
+ }
+
+ return 1;
+}
+#endif
+
+/*
+ * Register our module into parport.
+ * Pass also 2 callbacks functions to parport: a pre-emptive function and an
+ * interrupt handler function (unused).
+ * Display a message such "tipar0: using parport0 (polling)".
+ */
+static int tipar_register(int nr, struct parport *port)
+{
+ char name[8];
+
+ /* Register our module into parport */
+ table[nr].dev = parport_register_device(port, "tipar",
+ NULL, NULL, NULL, 0,
+ (void *) &table[nr]);
+
+ if (table[nr].dev == NULL)
+ return 1;
+
+ /* Use devfs, tree: /dev/ticables/par/[0..2] */
+ sprintf(name, "%d", nr);
+ printk("tipar: registering to devfs : major = %d, minor = %d, node = %s\n", TISER_MAJOR, (TIPAR_MINOR + nr), name);
+ devfs_register(devfs_handle, name,
+ DEVFS_FL_DEFAULT, TIPAR_MAJOR, TIPAR_MINOR + nr,
+ S_IFCHR | S_IRUGO | S_IWUGO,
+ &tipar_fops, NULL);
+
+ /* Display informations */
+ printk(KERN_INFO "tipar%d: using %s (%s).\n", nr, port->name,
+ (port->irq == PARPORT_IRQ_NONE) ? "polling" : "interrupt-driven");
+
+ if (probe_ti_parallel(nr) != -1)
+ printk("tipar%d: link cable found !\n", nr);
+ else
+ printk("tipar%d: link cable not found.\n", nr);
+
+ return 0;
+}
+
+static void tipar_attach (struct parport *port)
+{
+ if (tp_count == PP_NO) {
+ printk("tipar: ignoring parallel port (max. %d)\n",
+ PP_NO);
+ return;
+ }
+
+ if (!tipar_register(tp_count, port))
+ tp_count++;
+}
+
+static void tipar_detach (struct parport *port)
+{
+ /* Nothing to do */
+}
+
+static struct parport_driver tipar_driver = {
+ "tipar",
+ tipar_attach,
+ tipar_detach,
+ NULL
+};
+
+int __init tipar_init_module(void)
+{
+ printk("tipar: parallel link cable driver, version %s\n", DRIVER_VERSION);
+
+ if (devfs_register_chrdev (TIPAR_MAJOR, "tipar", &tipar_fops)) {
+ printk("tipar: unable to get major %d\n", TIPAR_MAJOR);
+ return -EIO;
+ }
+
+ /* Use devfs with tree: /dev/ticables/par/[0..2] */
+ devfs_handle = devfs_mk_dir (NULL, "ticables/par", NULL);
+
+ if (parport_register_driver (&tipar_driver)) {
+ printk ("tipar: unable to register with parport\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+void __exit tipar_cleanup_module(void)
+{
+ unsigned int i;
+
+ /* Unregistering module */
+ parport_unregister_driver (&tipar_driver);
+
+ devfs_unregister (devfs_handle);
+ devfs_unregister_chrdev(TIPAR_MAJOR, "tipar");
+
+ for (i = 0; i < PP_NO; i++) {
+ if (table[i].dev == NULL)
+ continue;
+ parport_unregister_device(table[i].dev);
+ }
+
+ printk("tipar: module unloaded !\n");
+}
+
+/* --------------------------------------------------------------------- */
+
+__setup("tipar=", tipar_setup);
+module_init(tipar_init_module);
+module_exit(tipar_cleanup_module);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE(DRIVER_LICENSE);
+
+EXPORT_NO_SYMBOLS;
+
+MODULE_PARM(timeout, "i");
+MODULE_PARM_DESC(timeout, "Timeout (default=1.5 seconds)");
+MODULE_PARM(delay, "i");
+MODULE_PARM_DESC(delay, "Inter-bit delay (default=10 microseconds)");