From: Alexander Barton Date: Mon, 5 Jan 2009 01:30:31 +0000 (+0100) Subject: Parallel Port PIN driver for Linux 2.6: ppin X-Git-Url: https://arthur.barton.de/gitweb/?p=ppin.git;a=commitdiff_plain;h=f89a89c19c4960ca6762971328a30014366e881e Parallel Port PIN driver for Linux 2.6: ppin This kernel module will register the /dev/ppin (10, 151) device which controls up to eight PINs through the first parallel port. Controlling the PINs is as easy as 'echo Num State >/dev/ppin', where Num is 0 to 7 and State is one of 'on', 'off'. For example: "echo 3 on >/dev/ppin" switches the 3rd PIN on. You can read the status of the PINs with 'cat /dev/ppin'. 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 Free Software Foundation; either version 2 of the License, or (at your option) any later version. Authors: Alexander Barton, (for Linux 2.6, 2009) This work is heavily(!) based on the "devled" driver written by Konstantinos Natsakis, for Linux 2.2/2.4. Please note that documentation is mostly lacking at the moment -- use the source, luke ;-) --- f89a89c19c4960ca6762971328a30014366e881e diff --git a/COPYING b/COPYING new file mode 100644 index 0000000..d511905 --- /dev/null +++ b/COPYING @@ -0,0 +1,339 @@ + GNU GENERAL PUBLIC LICENSE + Version 2, June 1991 + + Copyright (C) 1989, 1991 Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The licenses for most software are designed to take away your +freedom to share and change it. By contrast, the GNU General Public +License is intended to guarantee your freedom to share and change free +software--to make sure the software is free for all its users. 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If this is what you want to do, use the GNU Lesser General +Public License instead of this License. diff --git a/ChangeLog b/ChangeLog new file mode 100644 index 0000000..e69de29 diff --git a/INSTALL b/INSTALL new file mode 100644 index 0000000..e69de29 diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..8de0ca8 --- /dev/null +++ b/Makefile @@ -0,0 +1,23 @@ +ifeq ($(KERNELRELEASE),) + +# normal Makefile + +KERNELDIR := /lib/modules/`uname -r`/build + +all: + $(MAKE) -C $(KERNELDIR) M=`pwd` CONFIG_PPIN=m modules + +modules_install: + $(MAKE) -C $(KERNELDIR) M=`pwd` modules_install + +clean: + $(MAKE) -C $(KERNELDIR) M=`pwd` clean + rm -f modules.order + +else + +# kbuild part of makefile + +obj-$(CONFIG_PPIN) := ppin.o + +endif diff --git a/README b/README new file mode 100644 index 0000000..e69de29 diff --git a/ppin.c b/ppin.c new file mode 100644 index 0000000..9fc504d --- /dev/null +++ b/ppin.c @@ -0,0 +1,225 @@ +/* + * Parallel Port PIN driver for Linux 2.6: ppin + * + * This kernel module will register the /dev/ppin (10, 151) + * device which controls up to eight PINs through the first + * parallel port. + * + * Controlling the PINs is as easy as 'echo Num State >/dev/ppin', + * where Num is 0 to 7 and State is one of 'on', 'off'. + * For example: "echo 3 on >/dev/ppin" switches the 3rd PIN on. + * + * You can read the status of the PINs with 'cat /dev/ppin'. + * + * 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 Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Authors: Alexander Barton, (for Linux 2.6, 2009) + * + * This work is heavily(!) based on the "devled" driver written by + * Konstantinos Natsakis, for Linux 2.2/2.4. + */ + +#include +#include +#include +#include + +#define PPIN_NAME "ppin" +#define PPIN_VERSION "0.1" + +#define PPIN_DEV "ppin" +#define PPIN_MAJOR MISC_MAJOR +#define PPIN_MINOR 151 + +#define ON_COMMAND "on" +#define OFF_COMMAND "off" + +static char pin_state = 0; +static int buffer_empty = 0; +static int ppin_open_cnt = 0; +static int available_ports = 0; +static struct pardevice *parport_pins = 0; + +MODULE_AUTHOR("Alexander Barton, alex@barton.de"); +MODULE_DESCRIPTION("Driver for controlling the state of parallel port PINs"); +MODULE_LICENSE("GPL"); + +static void +ppin_attach(struct parport *port) +{ + if (available_ports == 0) { + parport_pins = + parport_register_device(port, PPIN_DEV, NULL, NULL, + NULL, 0, 0); + + if (parport_pins == 0) + printk(KERN_ERR + "Could not associate " PPIN_DEV " device with parallel port #%d\n", + available_ports + 1); + else + printk(KERN_INFO + "Associated " PPIN_DEV " device with parallel port #%d\n", + available_ports + 1); + } + + available_ports++; +} + +static void +ppin_detach(struct parport *port) +{ + if (available_ports == 1) + parport_pins = 0; + + available_ports--; +} + +static struct parport_driver ppin_driver = { + PPIN_NAME, + ppin_attach, + ppin_detach, + NULL +}; + +static ssize_t +ppin_read(struct file *file, char *buf, size_t count, loff_t * ppos) +{ + int i; + char *tmp = buf; + char status[79]; + + if (buffer_empty) + return 0; + + sprintf(&status[0], + "PIN #: 0 1 2 3 4 5 6 7\n" + "State: %s %s %s %s %s %s %s %s\n", + pin_state & (1 << 0) ? " on" : "off", + pin_state & (1 << 1) ? " on" : "off", + pin_state & (1 << 2) ? " on" : "off", + pin_state & (1 << 3) ? " on" : "off", + pin_state & (1 << 4) ? " on" : "off", + pin_state & (1 << 5) ? " on" : "off", + pin_state & (1 << 6) ? " on" : "off", + pin_state & (1 << 7) ? " on" : "off"); + + for (i = 0; count-- > 0 && i < 78; ++i, ++tmp) + put_user(status[i], tmp); + + if (tmp - buf > 77) + buffer_empty = 1; + + return (tmp - buf); +} + +static ssize_t +ppin_write(struct file *file, const char *buf, size_t count, loff_t * ppos) +{ + int i; + char *tmp_1, *tmp_2; + + i = simple_strtol(buf, &tmp_2, 0); + + if (i < 0 || i > 7) { + printk(KERN_WARNING "" PPIN_DEV ": No such PIN: %d\n", i); + return count; + } + tmp_2++; + + tmp_1 = strstr(tmp_2, OFF_COMMAND); + if (tmp_1 != NULL) + pin_state &= ~(1 << i); + else { + tmp_1 = strstr(tmp_2, ON_COMMAND); + if (tmp_1 != NULL) + pin_state |= (1 << i); + } + + if (!tmp_1) { + printk(KERN_WARNING "" PPIN_DEV": No such state\n"); + return count; + } + + if (parport_claim_or_block(parport_pins) < 0) { + printk(KERN_ERR + "Could not claim the " PPIN_DEV " parallel port device\n"); + return 0; + } + + parport_write_data(parport_pins->port, pin_state); + + parport_release(parport_pins); + return count; +} + +static int +ppin_open(struct inode *inode, struct file *file) +{ + if (ppin_open_cnt) + return -EBUSY; + else + ppin_open_cnt = 1; + + buffer_empty = 0; + return 0; +} + +static int +ppin_release(struct inode *inode, struct file *file) +{ + ppin_open_cnt = 0; + return 0; +} + +static struct file_operations ppin_fops = { + owner:THIS_MODULE, + read:ppin_read, + write:ppin_write, + open:ppin_open, + release:ppin_release, +}; + +static struct miscdevice ppin_dev = { + PPIN_MINOR, + PPIN_DEV, + &ppin_fops +}; + +int __init +ppin_init(void) +{ + if (parport_register_driver(&ppin_driver) != 0) { + printk(KERN_ERR "Could not register the " PPIN_DEV " driver.\n"); + return -EIO; + } + + if (misc_register(&ppin_dev) != 0) { + printk(KERN_ERR + "Could not register the misc device " PPIN_DEV " (%d, %d)\n", + PPIN_MAJOR, PPIN_MINOR); + return -EIO; + } + + printk(KERN_INFO "" PPIN_NAME " driver v%s loaded\n", PPIN_VERSION); + return 0; +} + +static void __exit +ppin_cleanup(void) +{ + if (misc_deregister(&ppin_dev) != 0) + printk(KERN_ERR + "Cound not deregister the misc device " PPIN_DEV " (%d, %d)\n", + PPIN_MAJOR, PPIN_MINOR); + + parport_unregister_device(parport_pins); + parport_unregister_driver(&ppin_driver); + + printk(KERN_INFO "" PPIN_NAME " driver v%s unloaded\n", PPIN_VERSION); +} + +module_init(ppin_init); +module_exit(ppin_cleanup);