n_tracerouter and n_tracesink ldisc additions.

The n_tracerouter and n_tracesink line discpline drivers use the Linux tty line discpline framework to route trace data coming from a tty port (say UART for example) to the trace sink line discipline driver and to another tty port(say USB). Those these two line discipline drivers can be used together, independently from pti.c, they are part of the original implementation solution of the MIPI P1149.7, compact JTAG, PTI solution for Intel mobile platforms starting with the Medfield platform. Signed-off-by: J Freyensee <james_p_freyensee@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

n_tracerouter and n_tracesink ldisc additions.
The n_tracerouter and n_tracesink line discpline drivers use the Linux tty line discpline framework to route trace data coming from a tty port (say UART for example) to the trace sink line discipline driver and to another tty port(say USB). Those these two line discipline drivers can be used together, independently from pti.c, they are part of the original implementation solution of the MIPI P1149.7, compact JTAG, PTI solution for Intel mobile platforms starting with the Medfield platform. Signed-off-by: J Freyensee <james_p_freyensee@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
J Freyensee · Greg Kroah-Hartman
1 parent 0b61d2acb1
Showing 6 changed files with 552 additions and 0 deletions Side-by-side Diff
drivers/tty/Kconfig
drivers/tty/Makefile
drivers/tty/n_tracerouter.c
drivers/tty/n_tracesink.c
drivers/tty/n_tracesink.h
include/linux/tty.h
@@ -318,4 +318,36 @@
 	help
 	  This line discipline provides support for the GSM MUX protocol and
 	  presents the mux as a set of 61 individual tty devices.
+
+config TRACE_ROUTER
+	tristate "Trace data router for MIPI P1149.7 cJTAG standard"
+	depends on TRACE_SINK
+	default n
+	help
+	  The trace router uses the Linux tty line discipline framework to
+	  route trace data coming from a tty port (say UART for example) to
+	  the trace sink line discipline driver and to another tty port (say
+	  USB). This is part of a solution for the MIPI P1149.7, compact JTAG,
+	  standard, which is for debugging mobile devices. The PTI driver in
+	  drivers/misc/pti.c defines the majority of this MIPI solution.
+
+	  You should select this driver if the target kernel is meant for
+	  a mobile device containing a modem.  Then you will need to select
+	  "Trace data sink for MIPI P1149.7 cJTAG standard" line discipline
+	  driver.
+
+config TRACE_SINK
+	tristate "Trace data sink for MIPI P1149.7 cJTAG standard"
+	default n
+	help
+	  The trace sink uses the Linux line discipline framework to receive
+	  trace data coming from the trace router line discipline driver
+	  to a user-defined tty port target, like USB.
+	  This is to provide a way to extract modem trace data on
+	  devices that do not have a PTI HW module, or just need modem
+	  trace data to come out of a different HW output port.
+	  This is part of a solution for the P1149.7, compact JTAG, standard.
+
+	  If you select this option, you need to select
+	  "Trace data router for MIPI P1149.7 cJTAG standard".
@@ -6,6 +6,8 @@
 obj-$(CONFIG_MAGIC_SYSRQ)	+= sysrq.o
 obj-$(CONFIG_N_HDLC)		+= n_hdlc.o
 obj-$(CONFIG_N_GSM)		+= n_gsm.o
+obj-$(CONFIG_TRACE_ROUTER)	+= n_tracerouter.o
+obj-$(CONFIG_TRACE_SINK)	+= n_tracesink.o
 obj-$(CONFIG_R3964)		+= n_r3964.o
  
 obj-y				+= vt/
+/*
+ *  n_tracerouter.c - Trace data router through tty space
+ *
+ *  Copyright (C) Intel 2011
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  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.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * This trace router uses the Linux line discipline framework to route
+ * trace data coming from a HW Modem to a PTI (Parallel Trace Module) port.
+ * The solution is not specific to a HW modem and this line disciple can
+ * be used to route any stream of data in kernel space.
+ * This is part of a solution for the P1149.7, compact JTAG, standard.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/ioctl.h>
+#include <linux/tty.h>
+#include <linux/tty_ldisc.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <asm-generic/bug.h>
+#include "n_tracesink.h"
+
+/*
+ * Other ldisc drivers use 65536 which basically means,
+ * 'I can always accept 64k' and flow control is off.
+ * This number is deemed appropriate for this driver.
+ */
+#define RECEIVE_ROOM	65536
+#define DRIVERNAME	"n_tracerouter"
+
+/*
+ * struct to hold private configuration data for this ldisc.
+ * opencalled is used to hold if this ldisc has been opened.
+ * kref_tty holds the tty reference the ldisc sits on top of.
+ */
+struct tracerouter_data {
+	u8 opencalled;
+	struct tty_struct *kref_tty;
+};
+static struct tracerouter_data *tr_data;
+
+/* lock for when tty reference is being used */
+static DEFINE_MUTEX(routelock);
+
+/**
+ * n_tracerouter_open() - Called when a tty is opened by a SW entity.
+ * @tty: terminal device to the ldisc.
+ *
+ * Return:
+ *      0 for success.
+ *
+ * Caveats: This should only be opened one time per SW entity.
+ */
+static int n_tracerouter_open(struct tty_struct *tty)
+{
+	int retval = -EEXIST;
+
+	mutex_lock(&routelock);
+	if (tr_data->opencalled == 0) {
+
+		tr_data->kref_tty = tty_kref_get(tty);
+		if (tr_data->kref_tty == NULL) {
+			retval = -EFAULT;
+		} else {
+			tr_data->opencalled = 1;
+			tty->disc_data      = tr_data;
+			tty->receive_room   = RECEIVE_ROOM;
+			tty_driver_flush_buffer(tty);
+			retval = 0;
+		}
+	}
+	mutex_unlock(&routelock);
+	return retval;
+}
+
+/**
+ * n_tracerouter_close() - close connection
+ * @tty: terminal device to the ldisc.
+ *
+ * Called when a software entity wants to close a connection.
+ */
+static void n_tracerouter_close(struct tty_struct *tty)
+{
+	struct tracerouter_data *tptr = tty->disc_data;
+
+	mutex_lock(&routelock);
+	WARN_ON(tptr->kref_tty != tr_data->kref_tty);
+	tty_driver_flush_buffer(tty);
+	tty_kref_put(tr_data->kref_tty);
+	tr_data->kref_tty = NULL;
+	tr_data->opencalled = 0;
+	tty->disc_data = NULL;
+	mutex_unlock(&routelock);
+}
+
+/**
+ * n_tracerouter_read() - read request from user space
+ * @tty:  terminal device passed into the ldisc.
+ * @file: pointer to open file object.
+ * @buf:  pointer to the data buffer that gets eventually returned.
+ * @nr:   number of bytes of the data buffer that is returned.
+ *
+ * function that allows read() functionality in userspace. By default if this
+ * is not implemented it returns -EIO. This module is functioning like a
+ * router via n_tracerouter_receivebuf(), and there is no real requirement
+ * to implement this function. However, an error return value other than
+ * -EIO should be used just to show that there was an intent not to have
+ * this function implemented.  Return value based on read() man pages.
+ *
+ * Return:
+ *	 -EINVAL
+ */
+static ssize_t n_tracerouter_read(struct tty_struct *tty, struct file *file,
+				  unsigned char __user *buf, size_t nr) {
+	return -EINVAL;
+}
+
+/**
+ * n_tracerouter_write() - Function that allows write() in userspace.
+ * @tty:  terminal device passed into the ldisc.
+ * @file: pointer to open file object.
+ * @buf:  pointer to the data buffer that gets eventually returned.
+ * @nr:   number of bytes of the data buffer that is returned.
+ *
+ * By default if this is not implemented, it returns -EIO.
+ * This should not be implemented, ever, because
+ * 1. this driver is functioning like a router via
+ *    n_tracerouter_receivebuf()
+ * 2. No writes to HW will ever go through this line discpline driver.
+ * However, an error return value other than -EIO should be used
+ * just to show that there was an intent not to have this function
+ * implemented.  Return value based on write() man pages.
+ *
+ * Return:
+ *	-EINVAL
+ */
+static ssize_t n_tracerouter_write(struct tty_struct *tty, struct file *file,
+				   const unsigned char *buf, size_t nr) {
+	return -EINVAL;
+}
+
+/**
+ * n_tracerouter_receivebuf() - Routing function for driver.
+ * @tty: terminal device passed into the ldisc.  It's assumed
+ *       tty will never be NULL.
+ * @cp:  buffer, block of characters to be eventually read by
+ *       someone, somewhere (user read() call or some kernel function).
+ * @fp:  flag buffer.
+ * @count: number of characters (aka, bytes) in cp.
+ *
+ * This function takes the input buffer, cp, and passes it to
+ * an external API function for processing.
+ */
+static void n_tracerouter_receivebuf(struct tty_struct *tty,
+					const unsigned char *cp,
+					char *fp, int count)
+{
+	mutex_lock(&routelock);
+	n_tracesink_datadrain((u8 *) cp, count);
+	mutex_unlock(&routelock);
+}
+
+/*
+ * Flush buffer is not impelemented as the ldisc has no internal buffering
+ * so the tty_driver_flush_buffer() is sufficient for this driver's needs.
+ */
+
+static struct tty_ldisc_ops tty_ptirouter_ldisc = {
+	.owner		= THIS_MODULE,
+	.magic		= TTY_LDISC_MAGIC,
+	.name		= DRIVERNAME,
+	.open		= n_tracerouter_open,
+	.close		= n_tracerouter_close,
+	.read		= n_tracerouter_read,
+	.write		= n_tracerouter_write,
+	.receive_buf	= n_tracerouter_receivebuf
+};
+
+/**
+ * n_tracerouter_init -	module initialisation
+ *
+ * Registers this module as a line discipline driver.
+ *
+ * Return:
+ *	0 for success, any other value error.
+ */
+static int __init n_tracerouter_init(void)
+{
+	int retval;
+
+	tr_data = kzalloc(sizeof(struct tracerouter_data), GFP_KERNEL);
+	if (tr_data == NULL)
+		return -ENOMEM;
+
+
+	/* Note N_TRACEROUTER is defined in linux/tty.h */
+	retval = tty_register_ldisc(N_TRACEROUTER, &tty_ptirouter_ldisc);
+	if (retval < 0) {
+		pr_err("%s: Registration failed: %d\n", __func__, retval);
+		kfree(tr_data);
+	}
+	return retval;
+}
+
+/**
+ * n_tracerouter_exit -	module unload
+ *
+ * Removes this module as a line discipline driver.
+ */
+static void __exit n_tracerouter_exit(void)
+{
+	int retval = tty_unregister_ldisc(N_TRACEROUTER);
+
+	if (retval < 0)
+		pr_err("%s: Unregistration failed: %d\n", __func__,  retval);
+	else
+		kfree(tr_data);
+}
+
+module_init(n_tracerouter_init);
+module_exit(n_tracerouter_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jay Freyensee");
+MODULE_ALIAS_LDISC(N_TRACEROUTER);
+MODULE_DESCRIPTION("Trace router ldisc driver");
+/*
+ *  n_tracesink.c - Trace data router and sink path through tty space.
+ *
+ *  Copyright (C) Intel 2011
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  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.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * The trace sink uses the Linux line discipline framework to receive
+ * trace data coming from the PTI source line discipline driver
+ * to a user-desired tty port, like USB.
+ * This is to provide a way to extract modem trace data on
+ * devices that do not have a PTI HW module, or just need modem
+ * trace data to come out of a different HW output port.
+ * This is part of a solution for the P1149.7, compact JTAG, standard.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/ioctl.h>
+#include <linux/tty.h>
+#include <linux/tty_ldisc.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <asm-generic/bug.h>
+#include "n_tracesink.h"
+
+/*
+ * Other ldisc drivers use 65536 which basically means,
+ * 'I can always accept 64k' and flow control is off.
+ * This number is deemed appropriate for this driver.
+ */
+#define RECEIVE_ROOM	65536
+#define DRIVERNAME	"n_tracesink"
+
+/*
+ * there is a quirk with this ldisc is he can write data
+ * to a tty from anyone calling his kernel API, which
+ * meets customer requirements in the drivers/misc/pti.c
+ * project.  So he needs to know when he can and cannot write when
+ * the API is called. In theory, the API can be called
+ * after an init() but before a successful open() which
+ * would crash the system if tty is not checked.
+ */
+static struct tty_struct *this_tty;
+static DEFINE_MUTEX(writelock);
+
+/**
+ * n_tracesink_open() - Called when a tty is opened by a SW entity.
+ * @tty: terminal device to the ldisc.
+ *
+ * Return:
+ *      0 for success,
+ *      -EFAULT = couldn't get a tty kref n_tracesink will sit
+ *       on top of
+ *      -EEXIST = open() called successfully once and it cannot
+ *      be called again.
+ *
+ * Caveats: open() should only be successful the first time a
+ * SW entity calls it.
+ */
+static int n_tracesink_open(struct tty_struct *tty)
+{
+	int retval = -EEXIST;
+
+	mutex_lock(&writelock);
+	if (this_tty == NULL) {
+		this_tty = tty_kref_get(tty);
+		if (this_tty == NULL) {
+			retval = -EFAULT;
+		} else {
+			tty->disc_data = this_tty;
+			tty_driver_flush_buffer(tty);
+			retval = 0;
+		}
+	}
+	mutex_unlock(&writelock);
+
+	return retval;
+}
+
+/**
+ * n_tracesink_close() - close connection
+ * @tty: terminal device to the ldisc.
+ *
+ * Called when a software entity wants to close a connection.
+ */
+static void n_tracesink_close(struct tty_struct *tty)
+{
+	mutex_lock(&writelock);
+	tty_driver_flush_buffer(tty);
+	tty_kref_put(this_tty);
+	this_tty = NULL;
+	tty->disc_data = NULL;
+	mutex_unlock(&writelock);
+}
+
+/**
+ * n_tracesink_read() - read request from user space
+ * @tty:  terminal device passed into the ldisc.
+ * @file: pointer to open file object.
+ * @buf:  pointer to the data buffer that gets eventually returned.
+ * @nr:   number of bytes of the data buffer that is returned.
+ *
+ * function that allows read() functionality in userspace. By default if this
+ * is not implemented it returns -EIO. This module is functioning like a
+ * router via n_tracesink_receivebuf(), and there is no real requirement
+ * to implement this function. However, an error return value other than
+ * -EIO should be used just to show that there was an intent not to have
+ * this function implemented.  Return value based on read() man pages.
+ *
+ * Return:
+ *	 -EINVAL
+ */
+static ssize_t n_tracesink_read(struct tty_struct *tty, struct file *file,
+				unsigned char __user *buf, size_t nr) {
+	return -EINVAL;
+}
+
+/**
+ * n_tracesink_write() - Function that allows write() in userspace.
+ * @tty:  terminal device passed into the ldisc.
+ * @file: pointer to open file object.
+ * @buf:  pointer to the data buffer that gets eventually returned.
+ * @nr:   number of bytes of the data buffer that is returned.
+ *
+ * By default if this is not implemented, it returns -EIO.
+ * This should not be implemented, ever, because
+ * 1. this driver is functioning like a router via
+ *    n_tracesink_receivebuf()
+ * 2. No writes to HW will ever go through this line discpline driver.
+ * However, an error return value other than -EIO should be used
+ * just to show that there was an intent not to have this function
+ * implemented.  Return value based on write() man pages.
+ *
+ * Return:
+ *	-EINVAL
+ */
+static ssize_t n_tracesink_write(struct tty_struct *tty, struct file *file,
+				 const unsigned char *buf, size_t nr) {
+	return -EINVAL;
+}
+
+/**
+ * n_tracesink_datadrain() - Kernel API function used to route
+ *			     trace debugging data to user-defined
+ *			     port like USB.
+ *
+ * @buf:   Trace debuging data buffer to write to tty target
+ *         port. Null value will return with no write occurring.
+ * @count: Size of buf. Value of 0 or a negative number will
+ *         return with no write occuring.
+ *
+ * Caveat: If this line discipline does not set the tty it sits
+ * on top of via an open() call, this API function will not
+ * call the tty's write() call because it will have no pointer
+ * to call the write().
+ */
+void n_tracesink_datadrain(u8 *buf, int count)
+{
+	mutex_lock(&writelock);
+
+	if ((buf != NULL) && (count > 0) && (this_tty != NULL))
+		this_tty->ops->write(this_tty, buf, count);
+
+	mutex_unlock(&writelock);
+}
+EXPORT_SYMBOL_GPL(n_tracesink_datadrain);
+
+/*
+ * Flush buffer is not impelemented as the ldisc has no internal buffering
+ * so the tty_driver_flush_buffer() is sufficient for this driver's needs.
+ */
+
+/*
+ * tty_ldisc function operations for this driver.
+ */
+static struct tty_ldisc_ops tty_n_tracesink = {
+	.owner		= THIS_MODULE,
+	.magic		= TTY_LDISC_MAGIC,
+	.name		= DRIVERNAME,
+	.open		= n_tracesink_open,
+	.close		= n_tracesink_close,
+	.read		= n_tracesink_read,
+	.write		= n_tracesink_write
+};
+
+/**
+ * n_tracesink_init-	module initialisation
+ *
+ * Registers this module as a line discipline driver.
+ *
+ * Return:
+ *	0 for success, any other value error.
+ */
+static int __init n_tracesink_init(void)
+{
+	/* Note N_TRACESINK is defined in linux/tty.h */
+	int retval = tty_register_ldisc(N_TRACESINK, &tty_n_tracesink);
+
+	if (retval < 0)
+		pr_err("%s: Registration failed: %d\n", __func__, retval);
+
+	return retval;
+}
+
+/**
+ * n_tracesink_exit -	module unload
+ *
+ * Removes this module as a line discipline driver.
+ */
+static void __exit n_tracesink_exit(void)
+{
+	int retval = tty_unregister_ldisc(N_TRACESINK);
+
+	if (retval < 0)
+		pr_err("%s: Unregistration failed: %d\n", __func__,  retval);
+}
+
+module_init(n_tracesink_init);
+module_exit(n_tracesink_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jay Freyensee");
+MODULE_ALIAS_LDISC(N_TRACESINK);
+MODULE_DESCRIPTION("Trace sink ldisc driver");
+/*
+ *  n_tracesink.h - Kernel driver API to route trace data in kernel space.
+ *
+ *  Copyright (C) Intel 2011
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  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.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * The PTI (Parallel Trace Interface) driver directs trace data routed from
+ * various parts in the system out through the Intel Penwell PTI port and
+ * out of the mobile device for analysis with a debugging tool
+ * (Lauterbach, Fido). This is part of a solution for the MIPI P1149.7,
+ * compact JTAG, standard.
+ *
+ * This header file is used by n_tracerouter to be able to send the
+ * data of it's tty port to the tty port this module sits.  This
+ * mechanism can also be used independent of the PTI module.
+ *
+ */
+
+#ifndef N_TRACESINK_H_
+#define N_TRACESINK_H_
+
+void n_tracesink_datadrain(u8 *buf, int count);
+
+#endif
@@ -50,6 +50,8 @@
 #define N_CAIF		20      /* CAIF protocol for talking to modems */
 #define N_GSM0710	21	/* GSM 0710 Mux */
 #define N_TI_WL		22	/* for TI's WL BT, FM, GPS combo chips */
+#define N_TRACESINK	23	/* Trace data routing for MIPI P1149.7 */
+#define N_TRACEROUTER	24	/* Trace data routing for MIPI P1149.7 */
  
 /*
  * This character is the same as _POSIX_VDISABLE: it cannot be used as
...	...	@@ -318,4 +318,36 @@
318	318	help
319	319	This line discipline provides support for the GSM MUX protocol and
320	320	presents the mux as a set of 61 individual tty devices.
	321	+
	322	+config TRACE_ROUTER
	323	+ tristate "Trace data router for MIPI P1149.7 cJTAG standard"
	324	+ depends on TRACE_SINK
	325	+ default n
	326	+ help
	327	+ The trace router uses the Linux tty line discipline framework to
	328	+ route trace data coming from a tty port (say UART for example) to
	329	+ the trace sink line discipline driver and to another tty port (say
	330	+ USB). This is part of a solution for the MIPI P1149.7, compact JTAG,
	331	+ standard, which is for debugging mobile devices. The PTI driver in
	332	+ drivers/misc/pti.c defines the majority of this MIPI solution.
	333	+
	334	+ You should select this driver if the target kernel is meant for
	335	+ a mobile device containing a modem. Then you will need to select
	336	+ "Trace data sink for MIPI P1149.7 cJTAG standard" line discipline
	337	+ driver.
	338	+
	339	+config TRACE_SINK
	340	+ tristate "Trace data sink for MIPI P1149.7 cJTAG standard"
	341	+ default n
	342	+ help
	343	+ The trace sink uses the Linux line discipline framework to receive
	344	+ trace data coming from the trace router line discipline driver
	345	+ to a user-defined tty port target, like USB.
	346	+ This is to provide a way to extract modem trace data on
	347	+ devices that do not have a PTI HW module, or just need modem
	348	+ trace data to come out of a different HW output port.
	349	+ This is part of a solution for the P1149.7, compact JTAG, standard.
	350	+
	351	+ If you select this option, you need to select
	352	+ "Trace data router for MIPI P1149.7 cJTAG standard".
...	...	@@ -6,6 +6,8 @@
6	6	obj-$(CONFIG_MAGIC_SYSRQ) += sysrq.o
7	7	obj-$(CONFIG_N_HDLC) += n_hdlc.o
8	8	obj-$(CONFIG_N_GSM) += n_gsm.o
	9	+obj-$(CONFIG_TRACE_ROUTER) += n_tracerouter.o
	10	+obj-$(CONFIG_TRACE_SINK) += n_tracesink.o
9	11	obj-$(CONFIG_R3964) += n_r3964.o
10	12
11	13	obj-y += vt/
	1	+/*
	2	+ * n_tracerouter.c - Trace data router through tty space
	3	+ *
	4	+ * Copyright (C) Intel 2011
	5	+ *
	6	+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	7	+ *
	8	+ * This program is free software; you can redistribute it and/or modify
	9	+ * it under the terms of the GNU General Public License version 2
	10	+ * as published by the Free Software Foundation.
	11	+ *
	12	+ * This program is distributed in the hope that it will be useful,
	13	+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	+ * GNU General Public License for more details.
	16	+ *
	17	+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	18	+ *
	19	+ * This trace router uses the Linux line discipline framework to route
	20	+ * trace data coming from a HW Modem to a PTI (Parallel Trace Module) port.
	21	+ * The solution is not specific to a HW modem and this line disciple can
	22	+ * be used to route any stream of data in kernel space.
	23	+ * This is part of a solution for the P1149.7, compact JTAG, standard.
	24	+ */
	25	+
	26	+#include <linux/init.h>
	27	+#include <linux/kernel.h>
	28	+#include <linux/module.h>
	29	+#include <linux/types.h>
	30	+#include <linux/ioctl.h>
	31	+#include <linux/tty.h>
	32	+#include <linux/tty_ldisc.h>
	33	+#include <linux/errno.h>
	34	+#include <linux/string.h>
	35	+#include <linux/mutex.h>
	36	+#include <linux/slab.h>
	37	+#include <asm-generic/bug.h>
	38	+#include "n_tracesink.h"
	39	+
	40	+/*
	41	+ * Other ldisc drivers use 65536 which basically means,
	42	+ * 'I can always accept 64k' and flow control is off.
	43	+ * This number is deemed appropriate for this driver.
	44	+ */
	45	+#define RECEIVE_ROOM 65536
	46	+#define DRIVERNAME "n_tracerouter"
	47	+
	48	+/*
	49	+ * struct to hold private configuration data for this ldisc.
	50	+ * opencalled is used to hold if this ldisc has been opened.
	51	+ * kref_tty holds the tty reference the ldisc sits on top of.
	52	+ */
	53	+struct tracerouter_data {
	54	+ u8 opencalled;
	55	+ struct tty_struct *kref_tty;
	56	+};
	57	+static struct tracerouter_data *tr_data;
	58	+
	59	+/* lock for when tty reference is being used */
	60	+static DEFINE_MUTEX(routelock);
	61	+
	62	+/**
	63	+ * n_tracerouter_open() - Called when a tty is opened by a SW entity.
	64	+ * @tty: terminal device to the ldisc.
	65	+ *
	66	+ * Return:
	67	+ * 0 for success.
	68	+ *
	69	+ * Caveats: This should only be opened one time per SW entity.
	70	+ */
	71	+static int n_tracerouter_open(struct tty_struct *tty)
	72	+{
	73	+ int retval = -EEXIST;
	74	+
	75	+ mutex_lock(&routelock);
	76	+ if (tr_data->opencalled == 0) {
	77	+
	78	+ tr_data->kref_tty = tty_kref_get(tty);
	79	+ if (tr_data->kref_tty == NULL) {
	80	+ retval = -EFAULT;
	81	+ } else {
	82	+ tr_data->opencalled = 1;
	83	+ tty->disc_data = tr_data;
	84	+ tty->receive_room = RECEIVE_ROOM;
	85	+ tty_driver_flush_buffer(tty);
	86	+ retval = 0;
	87	+ }
	88	+ }
	89	+ mutex_unlock(&routelock);
	90	+ return retval;
	91	+}
	92	+
	93	+/**
	94	+ * n_tracerouter_close() - close connection
	95	+ * @tty: terminal device to the ldisc.
	96	+ *
	97	+ * Called when a software entity wants to close a connection.
	98	+ */
	99	+static void n_tracerouter_close(struct tty_struct *tty)
	100	+{
	101	+ struct tracerouter_data *tptr = tty->disc_data;
	102	+
	103	+ mutex_lock(&routelock);
	104	+ WARN_ON(tptr->kref_tty != tr_data->kref_tty);
	105	+ tty_driver_flush_buffer(tty);
	106	+ tty_kref_put(tr_data->kref_tty);
	107	+ tr_data->kref_tty = NULL;
	108	+ tr_data->opencalled = 0;
	109	+ tty->disc_data = NULL;
	110	+ mutex_unlock(&routelock);
	111	+}
	112	+
	113	+/**
	114	+ * n_tracerouter_read() - read request from user space
	115	+ * @tty: terminal device passed into the ldisc.
	116	+ * @file: pointer to open file object.
	117	+ * @buf: pointer to the data buffer that gets eventually returned.
	118	+ * @nr: number of bytes of the data buffer that is returned.
	119	+ *
	120	+ * function that allows read() functionality in userspace. By default if this
	121	+ * is not implemented it returns -EIO. This module is functioning like a
	122	+ * router via n_tracerouter_receivebuf(), and there is no real requirement
	123	+ * to implement this function. However, an error return value other than
	124	+ * -EIO should be used just to show that there was an intent not to have
	125	+ * this function implemented. Return value based on read() man pages.
	126	+ *
	127	+ * Return:
	128	+ * -EINVAL
	129	+ */
	130	+static ssize_t n_tracerouter_read(struct tty_struct tty, struct file file,
	131	+ unsigned char __user *buf, size_t nr) {
	132	+ return -EINVAL;
	133	+}
	134	+
	135	+/**
	136	+ * n_tracerouter_write() - Function that allows write() in userspace.
	137	+ * @tty: terminal device passed into the ldisc.
	138	+ * @file: pointer to open file object.
	139	+ * @buf: pointer to the data buffer that gets eventually returned.
	140	+ * @nr: number of bytes of the data buffer that is returned.
	141	+ *
	142	+ * By default if this is not implemented, it returns -EIO.
	143	+ * This should not be implemented, ever, because
	144	+ * 1. this driver is functioning like a router via
	145	+ * n_tracerouter_receivebuf()
	146	+ * 2. No writes to HW will ever go through this line discpline driver.
	147	+ * However, an error return value other than -EIO should be used
	148	+ * just to show that there was an intent not to have this function
	149	+ * implemented. Return value based on write() man pages.
	150	+ *
	151	+ * Return:
	152	+ * -EINVAL
	153	+ */
	154	+static ssize_t n_tracerouter_write(struct tty_struct tty, struct file file,
	155	+ const unsigned char *buf, size_t nr) {
	156	+ return -EINVAL;
	157	+}
	158	+
	159	+/**
	160	+ * n_tracerouter_receivebuf() - Routing function for driver.
	161	+ * @tty: terminal device passed into the ldisc. It's assumed
	162	+ * tty will never be NULL.
	163	+ * @cp: buffer, block of characters to be eventually read by
	164	+ * someone, somewhere (user read() call or some kernel function).
	165	+ * @fp: flag buffer.
	166	+ * @count: number of characters (aka, bytes) in cp.
	167	+ *
	168	+ * This function takes the input buffer, cp, and passes it to
	169	+ * an external API function for processing.
	170	+ */
	171	+static void n_tracerouter_receivebuf(struct tty_struct *tty,
	172	+ const unsigned char *cp,
	173	+ char *fp, int count)
	174	+{
	175	+ mutex_lock(&routelock);
	176	+ n_tracesink_datadrain((u8 *) cp, count);
	177	+ mutex_unlock(&routelock);
	178	+}
	179	+
	180	+/*
	181	+ * Flush buffer is not impelemented as the ldisc has no internal buffering
	182	+ * so the tty_driver_flush_buffer() is sufficient for this driver's needs.
	183	+ */
	184	+
	185	+static struct tty_ldisc_ops tty_ptirouter_ldisc = {
	186	+ .owner = THIS_MODULE,
	187	+ .magic = TTY_LDISC_MAGIC,
	188	+ .name = DRIVERNAME,
	189	+ .open = n_tracerouter_open,
	190	+ .close = n_tracerouter_close,
	191	+ .read = n_tracerouter_read,
	192	+ .write = n_tracerouter_write,
	193	+ .receive_buf = n_tracerouter_receivebuf
	194	+};
	195	+
	196	+/**
	197	+ * n_tracerouter_init - module initialisation
	198	+ *
	199	+ * Registers this module as a line discipline driver.
	200	+ *
	201	+ * Return:
	202	+ * 0 for success, any other value error.
	203	+ */
	204	+static int __init n_tracerouter_init(void)
	205	+{
	206	+ int retval;
	207	+
	208	+ tr_data = kzalloc(sizeof(struct tracerouter_data), GFP_KERNEL);
	209	+ if (tr_data == NULL)
	210	+ return -ENOMEM;
	211	+
	212	+
	213	+ /* Note N_TRACEROUTER is defined in linux/tty.h */
	214	+ retval = tty_register_ldisc(N_TRACEROUTER, &tty_ptirouter_ldisc);
	215	+ if (retval < 0) {
	216	+ pr_err("%s: Registration failed: %d\n", __func__, retval);
	217	+ kfree(tr_data);
	218	+ }
	219	+ return retval;
	220	+}
	221	+
	222	+/**
	223	+ * n_tracerouter_exit - module unload
	224	+ *
	225	+ * Removes this module as a line discipline driver.
	226	+ */
	227	+static void __exit n_tracerouter_exit(void)
	228	+{
	229	+ int retval = tty_unregister_ldisc(N_TRACEROUTER);
	230	+
	231	+ if (retval < 0)
	232	+ pr_err("%s: Unregistration failed: %d\n", __func__, retval);
	233	+ else
	234	+ kfree(tr_data);
	235	+}
	236	+
	237	+module_init(n_tracerouter_init);
	238	+module_exit(n_tracerouter_exit);
	239	+
	240	+MODULE_LICENSE("GPL");
	241	+MODULE_AUTHOR("Jay Freyensee");
	242	+MODULE_ALIAS_LDISC(N_TRACEROUTER);
	243	+MODULE_DESCRIPTION("Trace router ldisc driver");
	1	+/*
	2	+ * n_tracesink.c - Trace data router and sink path through tty space.
	3	+ *
	4	+ * Copyright (C) Intel 2011
	5	+ *
	6	+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	7	+ *
	8	+ * This program is free software; you can redistribute it and/or modify
	9	+ * it under the terms of the GNU General Public License version 2
	10	+ * as published by the Free Software Foundation.
	11	+ *
	12	+ * This program is distributed in the hope that it will be useful,
	13	+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	+ * GNU General Public License for more details.
	16	+ *
	17	+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	18	+ *
	19	+ * The trace sink uses the Linux line discipline framework to receive
	20	+ * trace data coming from the PTI source line discipline driver
	21	+ * to a user-desired tty port, like USB.
	22	+ * This is to provide a way to extract modem trace data on
	23	+ * devices that do not have a PTI HW module, or just need modem
	24	+ * trace data to come out of a different HW output port.
	25	+ * This is part of a solution for the P1149.7, compact JTAG, standard.
	26	+ */
	27	+
	28	+#include <linux/init.h>
	29	+#include <linux/kernel.h>
	30	+#include <linux/module.h>
	31	+#include <linux/types.h>
	32	+#include <linux/ioctl.h>
	33	+#include <linux/tty.h>
	34	+#include <linux/tty_ldisc.h>
	35	+#include <linux/errno.h>
	36	+#include <linux/string.h>
	37	+#include <asm-generic/bug.h>
	38	+#include "n_tracesink.h"
	39	+
	40	+/*
	41	+ * Other ldisc drivers use 65536 which basically means,
	42	+ * 'I can always accept 64k' and flow control is off.
	43	+ * This number is deemed appropriate for this driver.
	44	+ */
	45	+#define RECEIVE_ROOM 65536
	46	+#define DRIVERNAME "n_tracesink"
	47	+
	48	+/*
	49	+ * there is a quirk with this ldisc is he can write data
	50	+ * to a tty from anyone calling his kernel API, which
	51	+ * meets customer requirements in the drivers/misc/pti.c
	52	+ * project. So he needs to know when he can and cannot write when
	53	+ * the API is called. In theory, the API can be called
	54	+ * after an init() but before a successful open() which
	55	+ * would crash the system if tty is not checked.
	56	+ */
	57	+static struct tty_struct *this_tty;
	58	+static DEFINE_MUTEX(writelock);
	59	+
	60	+/**
	61	+ * n_tracesink_open() - Called when a tty is opened by a SW entity.
	62	+ * @tty: terminal device to the ldisc.
	63	+ *
	64	+ * Return:
	65	+ * 0 for success,
	66	+ * -EFAULT = couldn't get a tty kref n_tracesink will sit
	67	+ * on top of
	68	+ * -EEXIST = open() called successfully once and it cannot
	69	+ * be called again.
	70	+ *
	71	+ * Caveats: open() should only be successful the first time a
	72	+ * SW entity calls it.
	73	+ */
	74	+static int n_tracesink_open(struct tty_struct *tty)
	75	+{
	76	+ int retval = -EEXIST;
	77	+
	78	+ mutex_lock(&writelock);
	79	+ if (this_tty == NULL) {
	80	+ this_tty = tty_kref_get(tty);
	81	+ if (this_tty == NULL) {
	82	+ retval = -EFAULT;
	83	+ } else {
	84	+ tty->disc_data = this_tty;
	85	+ tty_driver_flush_buffer(tty);
	86	+ retval = 0;
	87	+ }
	88	+ }
	89	+ mutex_unlock(&writelock);
	90	+
	91	+ return retval;
	92	+}
	93	+
	94	+/**
	95	+ * n_tracesink_close() - close connection
	96	+ * @tty: terminal device to the ldisc.
	97	+ *
	98	+ * Called when a software entity wants to close a connection.
	99	+ */
	100	+static void n_tracesink_close(struct tty_struct *tty)
	101	+{
	102	+ mutex_lock(&writelock);
	103	+ tty_driver_flush_buffer(tty);
	104	+ tty_kref_put(this_tty);
	105	+ this_tty = NULL;
	106	+ tty->disc_data = NULL;
	107	+ mutex_unlock(&writelock);
	108	+}
	109	+
	110	+/**
	111	+ * n_tracesink_read() - read request from user space
	112	+ * @tty: terminal device passed into the ldisc.
	113	+ * @file: pointer to open file object.
	114	+ * @buf: pointer to the data buffer that gets eventually returned.
	115	+ * @nr: number of bytes of the data buffer that is returned.
	116	+ *
	117	+ * function that allows read() functionality in userspace. By default if this
	118	+ * is not implemented it returns -EIO. This module is functioning like a
	119	+ * router via n_tracesink_receivebuf(), and there is no real requirement
	120	+ * to implement this function. However, an error return value other than
	121	+ * -EIO should be used just to show that there was an intent not to have
	122	+ * this function implemented. Return value based on read() man pages.
	123	+ *
	124	+ * Return:
	125	+ * -EINVAL
	126	+ */
	127	+static ssize_t n_tracesink_read(struct tty_struct tty, struct file file,
	128	+ unsigned char __user *buf, size_t nr) {
	129	+ return -EINVAL;
	130	+}
	131	+
	132	+/**
	133	+ * n_tracesink_write() - Function that allows write() in userspace.
	134	+ * @tty: terminal device passed into the ldisc.
	135	+ * @file: pointer to open file object.
	136	+ * @buf: pointer to the data buffer that gets eventually returned.
	137	+ * @nr: number of bytes of the data buffer that is returned.
	138	+ *
	139	+ * By default if this is not implemented, it returns -EIO.
	140	+ * This should not be implemented, ever, because
	141	+ * 1. this driver is functioning like a router via
	142	+ * n_tracesink_receivebuf()
	143	+ * 2. No writes to HW will ever go through this line discpline driver.
	144	+ * However, an error return value other than -EIO should be used
	145	+ * just to show that there was an intent not to have this function
	146	+ * implemented. Return value based on write() man pages.
	147	+ *
	148	+ * Return:
	149	+ * -EINVAL
	150	+ */
	151	+static ssize_t n_tracesink_write(struct tty_struct tty, struct file file,
	152	+ const unsigned char *buf, size_t nr) {
	153	+ return -EINVAL;
	154	+}
	155	+
	156	+/**
	157	+ * n_tracesink_datadrain() - Kernel API function used to route
	158	+ * trace debugging data to user-defined
	159	+ * port like USB.
	160	+ *
	161	+ * @buf: Trace debuging data buffer to write to tty target
	162	+ * port. Null value will return with no write occurring.
	163	+ * @count: Size of buf. Value of 0 or a negative number will
	164	+ * return with no write occuring.
	165	+ *
	166	+ * Caveat: If this line discipline does not set the tty it sits
	167	+ * on top of via an open() call, this API function will not
	168	+ * call the tty's write() call because it will have no pointer
	169	+ * to call the write().
	170	+ */
	171	+void n_tracesink_datadrain(u8 *buf, int count)
	172	+{
	173	+ mutex_lock(&writelock);
	174	+
	175	+ if ((buf != NULL) && (count > 0) && (this_tty != NULL))
	176	+ this_tty->ops->write(this_tty, buf, count);
	177	+
	178	+ mutex_unlock(&writelock);
	179	+}
	180	+EXPORT_SYMBOL_GPL(n_tracesink_datadrain);
	181	+
	182	+/*
	183	+ * Flush buffer is not impelemented as the ldisc has no internal buffering
	184	+ * so the tty_driver_flush_buffer() is sufficient for this driver's needs.
	185	+ */
	186	+
	187	+/*
	188	+ * tty_ldisc function operations for this driver.
	189	+ */
	190	+static struct tty_ldisc_ops tty_n_tracesink = {
	191	+ .owner = THIS_MODULE,
	192	+ .magic = TTY_LDISC_MAGIC,
	193	+ .name = DRIVERNAME,
	194	+ .open = n_tracesink_open,
	195	+ .close = n_tracesink_close,
	196	+ .read = n_tracesink_read,
	197	+ .write = n_tracesink_write
	198	+};
	199	+
	200	+/**
	201	+ * n_tracesink_init- module initialisation
	202	+ *
	203	+ * Registers this module as a line discipline driver.
	204	+ *
	205	+ * Return:
	206	+ * 0 for success, any other value error.
	207	+ */
	208	+static int __init n_tracesink_init(void)
	209	+{
	210	+ /* Note N_TRACESINK is defined in linux/tty.h */
	211	+ int retval = tty_register_ldisc(N_TRACESINK, &tty_n_tracesink);
	212	+
	213	+ if (retval < 0)
	214	+ pr_err("%s: Registration failed: %d\n", __func__, retval);
	215	+
	216	+ return retval;
	217	+}
	218	+
	219	+/**
	220	+ * n_tracesink_exit - module unload
	221	+ *
	222	+ * Removes this module as a line discipline driver.
	223	+ */
	224	+static void __exit n_tracesink_exit(void)
	225	+{
	226	+ int retval = tty_unregister_ldisc(N_TRACESINK);
	227	+
	228	+ if (retval < 0)
	229	+ pr_err("%s: Unregistration failed: %d\n", __func__, retval);
	230	+}
	231	+
	232	+module_init(n_tracesink_init);
	233	+module_exit(n_tracesink_exit);
	234	+
	235	+MODULE_LICENSE("GPL");
	236	+MODULE_AUTHOR("Jay Freyensee");
	237	+MODULE_ALIAS_LDISC(N_TRACESINK);
	238	+MODULE_DESCRIPTION("Trace sink ldisc driver");
	1	+/*
	2	+ * n_tracesink.h - Kernel driver API to route trace data in kernel space.
	3	+ *
	4	+ * Copyright (C) Intel 2011
	5	+ *
	6	+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	7	+ *
	8	+ * This program is free software; you can redistribute it and/or modify
	9	+ * it under the terms of the GNU General Public License version 2
	10	+ * as published by the Free Software Foundation.
	11	+ *
	12	+ * This program is distributed in the hope that it will be useful,
	13	+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	+ * GNU General Public License for more details.
	16	+ *
	17	+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	18	+ *
	19	+ * The PTI (Parallel Trace Interface) driver directs trace data routed from
	20	+ * various parts in the system out through the Intel Penwell PTI port and
	21	+ * out of the mobile device for analysis with a debugging tool
	22	+ * (Lauterbach, Fido). This is part of a solution for the MIPI P1149.7,
	23	+ * compact JTAG, standard.
	24	+ *
	25	+ * This header file is used by n_tracerouter to be able to send the
	26	+ * data of it's tty port to the tty port this module sits. This
	27	+ * mechanism can also be used independent of the PTI module.
	28	+ *
	29	+ */
	30	+
	31	+#ifndef N_TRACESINK_H_
	32	+#define N_TRACESINK_H_
	33	+
	34	+void n_tracesink_datadrain(u8 *buf, int count);
	35	+
	36	+#endif
...	...	@@ -50,6 +50,8 @@
50	50	#define N_CAIF 20 /* CAIF protocol for talking to modems */
51	51	#define N_GSM0710 21 /* GSM 0710 Mux */
52	52	#define N_TI_WL 22 /* for TI's WL BT, FM, GPS combo chips */
	53	+#define N_TRACESINK 23 /* Trace data routing for MIPI P1149.7 */
	54	+#define N_TRACEROUTER 24 /* Trace data routing for MIPI P1149.7 */
53	55
54	56	/*
55	57	* This character is the same as _POSIX_VDISABLE: it cannot be used as