[PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[james_p_freyensee]

From: J Freyensee <james_p_freyensee@linux.intel.com>

The PTI (Parallel Trace Interface) driver directs
trace data routed from various parts in the system out
through an Intel Penwell PTI port and out of the mobile
device for analysis with a debugging tool (Lauterbach or Fido).
Though n_tracesink and n_tracerouter line discipline drivers
are used to extract modem tracing data to the PTI driver
and other parts of an Intel mobile solution, the PTI driver
can be used independent of n_tracesink and n_tracerouter.

You should select this driver if the target kernel is meant for
an Intel Atom (non-netbook) mobile device containing a MIPI
P1149.7 standard implementation.

Signed-off-by: J Freyensee <james_p_freyensee@linux.intel.com>
---
 drivers/misc/Kconfig  |   12 +
 drivers/misc/Makefile |    1 +
 drivers/misc/pti.c    |  898 +++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/pti.h   |   39 +++
 4 files changed, 950 insertions(+), 0 deletions(-)
 create mode 100644 drivers/misc/pti.c
 create mode 100644 include/linux/pti.h

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 4e007c6..95baff1 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -144,6 +144,18 @@ config PHANTOM
 	  If you choose to build module, its name will be phantom. If unsure,
 	  say N here.
 
+config INTEL_MID_PTI
+        tristate "Parallel Trace Interface for MIPI P1149.7 cJTAG standard"
+        help
+          The PTI (Parallel Trace Interface) driver directs
+          trace data routed from various parts in the system out
+          through an Intel Penwell PTI port and out of the mobile
+          device for analysis with a debugging tool (Lauterbach or Fido).
+
+          You should select this driver if the target kernel is meant for
+          an Intel Atom (non-netbook) mobile device containing a MIPI
+          P1149.7 standard implementation.
+
 config SGI_IOC4
 	tristate "SGI IOC4 Base IO support"
 	depends on PCI
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index f546860..662aa3c 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_IBM_ASM)		+= ibmasm/
 obj-$(CONFIG_AD525X_DPOT)	+= ad525x_dpot.o
 obj-$(CONFIG_AD525X_DPOT_I2C)	+= ad525x_dpot-i2c.o
 obj-$(CONFIG_AD525X_DPOT_SPI)	+= ad525x_dpot-spi.o
+0bj-$(CONFIG_INTEL_MID_PTI)	+= pti.o
 obj-$(CONFIG_ATMEL_PWM)		+= atmel_pwm.o
 obj-$(CONFIG_ATMEL_SSC)		+= atmel-ssc.o
 obj-$(CONFIG_ATMEL_TCLIB)	+= atmel_tclib.o
diff --git a/drivers/misc/pti.c b/drivers/misc/pti.c
new file mode 100644
index 0000000..f3a2980
--- /dev/null
+++ b/drivers/misc/pti.c
@@ -0,0 +1,898 @@
+/*
+ *  pti.c - PTI driver for cJTAG data extration
+ *
+ *  Copyright (C) Intel 2010
+ *
+ * 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.
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/console.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/pci.h>
+#include <linux/mutex.h>
+#include <linux/miscdevice.h>
+#include <linux/pti.h>
+
+#define DRIVERNAME		"pti"
+#define PCINAME			"pciPTI"
+#define TTYNAME			"ttyPTI"
+#define CHARNAME		"pti"
+#define PTITTY_MINOR_START	0
+#define PTITTY_MINOR_NUM	2
+#define MAX_APP_IDS		16   /* 128 channel ids / u8 bit size */
+#define MAX_OS_IDS		16   /* 128 channel ids / u8 bit size */
+#define MAX_MODEM_IDS		16   /* 128 channel ids / u8 bit size */
+#define MODEM_BASE_ID		71   /* modem master ID address    */
+#define CONTROL_ID		72   /* control master ID address  */
+#define CONSOLE_ID		73   /* console master ID address  */
+#define OS_BASE_ID		74   /* base OS master ID address  */
+#define APP_BASE_ID		80   /* base App master ID address */
+#define CONTROL_FRAME_LEN	32   /* PTI control frame maximum size */
+#define USER_COPY_SIZE		8192 /* 8Kb buffer for user space copy */
+#define APERTURE_14		0x3800000 /* offset to first OS write addr */
+#define APERTURE_LEN		0x400000  /* address length */
+
+struct pti_tty {
+	struct pti_masterchannel *mc;
+};
+
+struct pti_dev {
+	struct tty_port port;
+	unsigned long pti_addr;
+	unsigned long aperture_base;
+	void __iomem *pti_ioaddr;
+	u8 ia_app[MAX_APP_IDS];
+	u8 ia_os[MAX_OS_IDS];
+	u8 ia_modem[MAX_MODEM_IDS];
+};
+
+/*
+   This protects access to ia_app, ia_os, and ia_modem,
+   which keeps track of channels allocated in
+   an aperture write id.
+*/
+static DEFINE_MUTEX(alloclock);
+
+static struct pci_device_id pci_ids[] __devinitconst = {
+		{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x82B) },
+		{0}
+};
+
+static struct tty_driver *pti_tty_driver;
+
+static struct pti_dev *drv_data;
+
+static unsigned int pti_console_channel;
+static unsigned int pti_control_channel;
+
+#define DTS 0x30		/* offset for last dword of a PTI message */
+
+/**
+ *  pti_write_to_aperture() - THE private write function to PTI HW.
+ *  @mc: The 'aperture'. It's part of a write address that holds
+ *       a master and channel ID.
+ *  @buf: Data being written to the HW that will ultimately be seen
+ *        in a debugging tool (Fido, Lauterbach).
+ *  @len: Size of buffer.
+ *
+ *  Since each aperture is specified by a unique
+ *  master/channel ID, no two processes will be writing
+ *  to the same aperture at the same time so no lock is required. The
+ *  PTI-Output agent will send these out in the order that they arrived, and
+ *  thus, it will intermix these messages. The debug tool can then later
+ *  regroup the appropriate message segments together reconstituting each
+ *  message.
+ */
+static void pti_write_to_aperture(struct pti_masterchannel *mc,
+				  u8 *buf,
+				  int len)
+{
+	int dwordcnt, final, i;
+	u32 ptiword;
+	u8 *p;
+	u32 __iomem *aperture;
+
+	p = buf;
+
+	/*
+	   calculate the aperture offset from the base using the master and
+	   channel id's.
+	*/
+	aperture = drv_data->pti_ioaddr + (mc->master << 15)
+		+ (mc->channel << 8);
+
+	dwordcnt = len >> 2;
+	final = len - (dwordcnt << 2);		/* final = trailing bytes */
+	if (final == 0 && dwordcnt != 0) {	/* always have a final dword */
+		final += 4;
+		dwordcnt--;
+	}
+
+	for (i = 0; i < dwordcnt; i++) {
+		ptiword = be32_to_cpu(*(u32 *)p);
+		p += 4;
+		iowrite32(ptiword, aperture);
+	}
+
+	aperture += DTS;		/* adding DTS signals that is EOM */
+
+	ptiword = 0;
+	for (i = 0; i < final; i++)
+		ptiword |= *p++ << (24-(8*i));
+
+	iowrite32(ptiword, aperture);
+	return;
+}
+
+/**
+ *  pti_control_frame_built_and_sent() - control frame build and send function.
+ *  @mc: The master / channel structure on which the function built a control
+ *  frame.
+ *
+ *  To be able to post process the PTI contents on host side, a control frame
+ *  is added before sending any PTI content. So the host side knows on
+ *  each PTI frame the name of the thread using a dedicated master / channel.
+ *  This function builds this frame and sends it to a master ID CONTROL_ID.
+ *  The overhead is only 32 bytes since the driver only writes to HW
+ *  in 32 byte chunks.
+ */
+
+static void pti_control_frame_built_and_sent(struct pti_masterchannel *mc)
+{
+	struct pti_masterchannel mccontrol = {.master = CONTROL_ID,
+					      .channel = 0};
+	const char *control_format = "%3d %3d %s";
+
+	char comm[sizeof(current->comm) + 1];
+	u8 control_frame[CONTROL_FRAME_LEN];
+
+	if (!in_interrupt())
+		get_task_comm(comm, current);
+	else
+		strcpy(comm, "Interrupt");
+
+	/* Ensure our buffer is zero terminated */
+	comm[sizeof(current->comm)] = 0;
+
+	mccontrol.channel = pti_control_channel;
+	pti_control_channel = (pti_control_channel + 1) & 0x7f;
+
+	snprintf(control_frame, CONTROL_FRAME_LEN, control_format, mc->master,
+		mc->channel, comm);
+	pti_write_to_aperture(&mccontrol, control_frame, strlen(control_frame));
+}
+
+/**
+ *  pti_write_full_frame_to_aperture() - high level function to write to PTI
+ *  @mc: The 'aperture'. It's part of a write address that holds
+ *       a master and channel ID.
+ *  @buf: Data being written to the HW that will ultimately be seen
+ *        in a debugging tool (Fido, Lauterbach).
+ *  @len: Size of buffer.
+ *
+ *  All threads sending data (either console, user space application, ...)
+ *  are calling the high level function to write to PTI meaning that it is
+ *  possible to add a control frame before sending the content.
+ */
+static void pti_write_full_frame_to_aperture(struct pti_masterchannel *mc,
+						const unsigned char *buf,
+						int len)
+{
+	pti_control_frame_built_and_sent(mc);
+	pti_write_to_aperture(mc, (u8 *)buf, len);
+}
+
+
+/**
+ * getID(): Allocate a master and channel ID.
+ *
+ * @IDarray:
+ * @max_IDS: The max amount of available write IDs to use.
+ * @baseID:  The starting SW channel ID, based on the Intel
+ *           PTI arch.
+ *
+ * @return: pti_masterchannel struct containing master, channel ID address,
+ * or 0 for error.
+ *
+ * Each bit in the arrays ia_app and ia_os correspond to a master and
+ * channel id. The bit is one if the id is taken and 0 if free. For
+ * every master there are 128 channel id's.
+ */
+static struct pti_masterchannel *getID(u8 *IDarray, int max_IDS, int baseID)
+{
+	struct pti_masterchannel *mc;
+	int i, j, mask;
+
+	mc = kmalloc(sizeof(struct pti_masterchannel), GFP_KERNEL);
+	if (mc == NULL)
+		return NULL;
+
+	/* look for a byte with a free bit */
+	for (i = 0; i < max_IDS; i++)
+		if (IDarray[i] != 0xff)
+			break;
+	if (i == max_IDS) {
+		kfree(mc);
+		return NULL;
+	}
+	/* find the bit in the 128 possible channel opportunities */
+	mask = 0x80;
+	for (j = 0; j < 8; j++) {
+		if ((IDarray[i] & mask) == 0)
+			break;
+		mask >>= 1;
+	}
+
+	/* grab it */
+	IDarray[i] |= mask;
+	mc->master  = baseID;
+	mc->channel = ((i & 0xf)<<3) + j;
+	/* write new master Id / channel Id allocation to channel control */
+	pti_control_frame_built_and_sent(mc);
+	return mc;
+}
+
+/*
+	The following three functions:
+	pti_request_mastercahannel(), mipi_release_masterchannel()
+	and pti_writedata() are an API for other kernel drivers to
+	access PTI.
+*/
+
+/**
+ * pti_request_masterchannel() - Kernel API function used to allocate
+ *                                a master, channel ID address to write to
+ *                                PTI HW.
+ * @type: 0- request Application  master, channel aperture ID write address.
+ *        1- request OS master, channel aperture ID write address.
+ *        2- request Modem master, channel aperture ID write
+ *           address.
+ *        Other values, error.
+ * @return: pti_masterchannel struct or 0 for error.
+ *
+ */
+struct pti_masterchannel *pti_request_masterchannel(u8 type)
+{
+	struct pti_masterchannel *mc;
+
+	mutex_lock(&alloclock);
+
+	switch (type) {
+
+	case 0:
+		mc = getID(drv_data->ia_app, MAX_APP_IDS, APP_BASE_ID);
+		break;
+
+	case 1:
+		mc = getID(drv_data->ia_os, MAX_OS_IDS, OS_BASE_ID);
+		break;
+
+	case 2:
+		mc = getID(drv_data->ia_modem, MAX_MODEM_IDS, MODEM_BASE_ID);
+		break;
+	default:
+		mc = NULL;
+	}
+
+	mutex_unlock(&alloclock);
+	return mc;
+}
+EXPORT_SYMBOL_GPL(pti_request_masterchannel);
+
+/**
+ * pti_release_masterchannel() - Kernel API function used to release
+ *                                a master, channel ID address
+ *                                used to write to PTI HW.
+ * @mc: master, channel apeture ID address to be released.
+ *
+ */
+void pti_release_masterchannel(struct pti_masterchannel *mc)
+{
+	u8 master, channel, i;
+
+	mutex_lock(&alloclock);
+
+	if (mc) {
+		master = mc->master;
+		channel = mc->channel;
+
+		if (master == APP_BASE_ID) {
+			i = channel >> 3;
+			drv_data->ia_app[i] &=  ~(0x80>>(channel & 0x7));
+		} else if (master == OS_BASE_ID) {
+			i = channel >> 3;
+			drv_data->ia_os[i] &= ~(0x80>>(channel & 0x7));
+		} else {
+			i = channel >> 3;
+			drv_data->ia_modem[i] &= ~(0x80>>(channel & 0x7));
+		}
+
+		kfree(mc);
+	}
+
+	mutex_unlock(&alloclock);
+}
+EXPORT_SYMBOL_GPL(pti_release_masterchannel);
+
+/**
+ * pti_writedata() - Kernel API function used to write trace
+ *                   debugging data to PTI HW.
+ *
+ * @mc:    Master, channel aperture ID address to write to.
+ *         Null value will return with no write occurring.
+ * @buf:   Trace debuging data to write to the PTI HW.
+ *         Null value will return with no write occurring.
+ * @count: Size of buf. Value of 0 or a negative number will
+ *         retrn with no write occuring.
+ */
+void pti_writedata(struct pti_masterchannel *mc, u8 *buf, int count)
+{
+	/*
+	   since this function is exported, this is treated like an
+	   API function, thus, all parameters should
+	   be checked for validity.
+	*/
+	if ((mc != NULL) && (buf != NULL) && (count > 0))
+		pti_write_to_aperture(mc, buf, count);
+	return;
+}
+EXPORT_SYMBOL_GPL(pti_writedata);
+
+static void __devexit pti_pci_remove(struct pci_dev *pdev)
+{
+	struct pti_dev *drv_data;
+
+	drv_data = pci_get_drvdata(pdev);
+	if (drv_data != NULL) {
+		pci_iounmap(pdev, drv_data->pti_ioaddr);
+		pci_set_drvdata(pdev, NULL);
+		kfree(drv_data);
+		pci_release_region(pdev, 1);
+		pci_disable_device(pdev);
+	}
+}
+
+/*
+   for the tty_driver_*() basic function descriptions, see tty_driver.h.
+   Specific header comments made for PTI-related specifics.
+*/
+
+/**
+ * pti_tty_driver_open()- Open an Application master, channel aperture
+ * ID to the PTI device via tty device.
+ *
+ * @param tty: tty interface.
+ * @param filp: filp interface pased to tty_port_open() call.
+ *
+ * @return int : Success = 0, otherwise fail.
+ *
+ * The main purpose of using the tty device interface is for
+ * each tty port to have a unique PTI write aperture.  In an
+ * example use case, ttyPTI0 gets syslogd and an APP aperture
+ * ID and ttyPTI1 is where the n_tracesink ldisc hooks to route
+ * modem messages into PTI.  Modem trace data does not have to
+ * go to ttyPTI1, but ttyPTI0 and ttyPTI1 do need to be distinct
+ * master IDs.  These messages go through the PTI HW and out of
+ * the handheld platform and to the Fido/Lauterbach device.
+ */
+static int pti_tty_driver_open(struct tty_struct *tty, struct file *filp)
+{
+	int ret = 0;
+
+	/*
+	   we actually want to allocate a new channel per open, per
+	   system arch.  HW gives more than plenty channels for a single
+	   system task to have its own channel to write trace data. This
+	   also removes a locking requirement for the actual write
+	   procedure.
+	*/
+	ret = tty_port_open(&drv_data->port, tty, filp);
+
+	return ret;
+}
+
+/**
+ * pti_tty_driver_close()- close tty device and release Application
+ * master, channel aperture ID to the PTI device via tty device.
+ *
+ * @param tty: tty interface.
+ * @param filp: filp interface pased to tty_port_close() call.
+ *
+ * The main purpose of using the tty device interface is to route
+ * syslog daemon messages to the PTI HW and out of the handheld platform
+ * and to the Fido/Lauterbach device.
+ */
+static void pti_tty_driver_close(struct tty_struct *tty, struct file *filp)
+{
+	tty_port_close(&drv_data->port, tty, filp);
+
+	return;
+}
+
+static int pti_tty_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	int idx = tty->index;
+	struct pti_tty *pti_tty_data;
+	struct pti_masterchannel *mc;
+	int ret = tty_init_termios(tty);
+
+	if (ret == 0) {
+		tty_driver_kref_get(driver);
+		tty->count++;
+		driver->ttys[idx] = tty;
+
+		pti_tty_data = kmalloc(sizeof(struct pti_tty), GFP_KERNEL);
+		if (pti_tty_data == NULL)
+			return -ENOMEM;
+
+		tty->driver_data = pti_tty_data;
+
+		if (idx == PTITTY_MINOR_START)
+			mc = pti_request_masterchannel(0);
+		else
+			mc = pti_request_masterchannel(2);
+
+		if (mc == NULL)
+			return -ENXIO;
+
+		pti_tty_data->mc = mc;
+	}
+
+	return ret;
+}
+
+static void pti_tty_cleanup(struct tty_struct *tty)
+{
+	struct pti_tty *pti_tty_data;
+	struct pti_masterchannel *mc;
+
+	pti_tty_data = tty->driver_data;
+
+	if (pti_tty_data != NULL) {
+		mc = pti_tty_data->mc;
+		pti_release_masterchannel(mc);
+		pti_tty_data->mc = NULL;
+	}
+
+	if (pti_tty_data != NULL)
+		kfree(pti_tty_data);
+
+	tty->driver_data = NULL;
+}
+
+/**
+ * pti_tty_driver_write():  Write trace debugging data through the char
+ * interface to the PTI HW.  Part of the misc device implementation.
+ *
+ * @param filp: Contains private data which is used to obtain
+ *              master, channel write ID.
+ * @param data: trace data to be written.
+ * @param len:  # of byte to write.
+ * @return int : # of bytes written, or error.
+ */
+static int pti_tty_driver_write(struct tty_struct *tty,
+	const unsigned char *buf, int len)
+{
+	struct pti_masterchannel *mc;
+	struct pti_tty *pti_tty_data;
+
+	pti_tty_data = tty->driver_data;
+	mc = pti_tty_data->mc;
+	pti_write_to_aperture(mc, (u8 *)buf, len);
+
+	return len;
+}
+
+static int pti_tty_write_room(struct tty_struct *tty)
+{
+	return 2048;
+}
+
+/**
+ * pti_char_open()- Open an Application master, channel aperture
+ * ID to the PTI device. Part of the misc device implementation.
+ *
+ * @param inode: not used.
+ * @param filp: Output- will have a masterchannel struct set containing
+ * the allocated application PTI aperture write address.
+ *
+ * @return int : Success = 0, otherwise fail.  As of right now,
+ *         it is not sure what needs to really be initialized
+ *         for open(), so it always returns 0.
+ */
+static int pti_char_open(struct inode *inode, struct file *filp)
+{
+	struct pti_masterchannel *mc;
+
+	mc = pti_request_masterchannel(0);
+	if (mc == NULL)
+		return -ENOMEM;
+	filp->private_data = mc;
+	return 0;
+}
+
+/**
+ * pti_char_release()-  Close a char channel to the PTI device. Part
+ * of the misc device implementation.
+ *
+ * @param inode: Not used in this implementaiton.
+ * @param filp: Contains private_data that contains the master, channel
+ * ID to be released by the PTI device.
+ *
+ * @return int : Success = 0
+ */
+static int pti_char_release(struct inode *inode, struct file *filp)
+{
+	pti_release_masterchannel(filp->private_data);
+	return 0;
+}
+
+/**
+ * pti_char_write():  Write trace debugging data through the char
+ * interface to the PTI HW.  Part of the misc device implementation.
+ *
+ * @param filp: Contains private data which is used to obtain
+ *              master, channel write ID.
+ * @param data: trace data to be written.
+ * @param len:  # of byte to write.
+ * @param ppose: Not used in this function implementation.
+ * @return int : # of bytes written, or error.
+ *
+ * Notes: From side discussions with Alan Cox and experimenting
+ * with PTI debug HW like Nokia's Fido box and Lauterbach
+ * devices, 8192 byte write buffer used by USER_COPY_SIZE was
+ * deemed an appropriate size for this type of usage with
+ * debugging HW.
+ */
+static ssize_t pti_char_write(struct file *filp, const char __user *data,
+			      size_t len, loff_t *ppose)
+{
+	struct pti_masterchannel *mc;
+	void *kbuf;
+	const char __user *tmp;
+	size_t size = USER_COPY_SIZE, n = 0;
+
+	tmp = data;
+	mc = filp->private_data;
+
+	kbuf = kmalloc(size, GFP_KERNEL);
+	if (kbuf == NULL)  {
+		pr_err("%s(%d): buf allocation failed\n",
+			__func__, __LINE__);
+		return 0;
+	}
+
+	do {
+		if (len - n > USER_COPY_SIZE)
+			size = USER_COPY_SIZE;
+		else
+			size = len - n;
+
+		if (copy_from_user(kbuf, tmp, size)) {
+			kfree(kbuf);
+			return n ? n : -EFAULT;
+		}
+
+		pti_write_to_aperture(mc, kbuf, size);
+		n  += size;
+		tmp += size;
+
+	} while (len > n);
+
+	kfree(kbuf);
+	kbuf = NULL;
+
+	return len;
+}
+
+static const struct tty_operations pti_tty_driver_ops = {
+	.open		= pti_tty_driver_open,
+	.close		= pti_tty_driver_close,
+	.write		= pti_tty_driver_write,
+	.write_room	= pti_tty_write_room,
+	.install	= pti_tty_install,
+	.cleanup	= pti_tty_cleanup
+};
+
+static const struct file_operations pti_char_driver_ops = {
+	.owner		= THIS_MODULE,
+	.write		= pti_char_write,
+	.open		= pti_char_open,
+	.release	= pti_char_release,
+};
+
+static struct miscdevice pti_char_driver = {
+	.minor		= MISC_DYNAMIC_MINOR,
+	.name		= CHARNAME,
+	.fops		= &pti_char_driver_ops
+};
+
+static void pti_console_write(struct console *c, const char *buf, unsigned len)
+{
+	static struct pti_masterchannel mc = {.master  = CONSOLE_ID,
+					      .channel = 0};
+
+	mc.channel = pti_console_channel;
+	pti_console_channel = (pti_console_channel + 1) & 0x7f;
+
+	pti_write_full_frame_to_aperture(&mc, buf, len);
+}
+
+static struct tty_driver *pti_console_device(struct console *c, int *index)
+{
+	*index = c->index;
+	return pti_tty_driver;
+}
+
+static int pti_console_setup(struct console *c, char *opts)
+{
+	pti_console_channel = 0;
+	pti_control_channel = 0;
+	return 0;
+}
+
+/* pti_console struct, used to capture OS printk()'s and shift
+ * out to the PTI device for debugging.  This cannot be
+ * enabled upon boot because of the possibility of eating
+ * any serial console printk's (race condition discovered).
+ * The console should be enabled upon when the tty port is
+ * used for the first time.  Since the primary purpose for
+ * the tty port is to hook up syslog to it, the tty port
+ * will be open for a really long time.
+ */
+static struct console pti_console = {
+	.name		= TTYNAME,
+	.write		= pti_console_write,
+	.device		= pti_console_device,
+	.setup		= pti_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= 0,
+};
+
+/**
+ * pti_port_activate(): Used to start/initialize any items upon
+ * first opening of tty_port().
+ *
+ * @param port- The tty port number of the PTI device.
+ * @param tty-  The tty struct associated with this device.
+ *
+ * @return int - Always returns 0.
+ *
+ * Notes: The primary purpose of the PTI tty port 0 is to hook
+ * the syslog daemon to it; thus this port will be open for a
+ * very long time.
+ */
+static int pti_port_activate(struct tty_port *port, struct tty_struct *tty)
+{
+	if (port->tty->index == PTITTY_MINOR_START)
+		console_start(&pti_console);
+	return 0;
+}
+
+/**
+ * pti_port_shutdown(): Used to stop/shutdown any items upon the
+ * last tty port close.
+ *
+ * @param port- The tty port number of the PTI device.
+ *
+ * Notes: The primary purpose of the PTI tty port 0 is to hook
+ * the syslog daemon to it; thus this port will be open for a
+ * very long time.
+ */
+static void pti_port_shutdown(struct tty_port *port)
+{
+	if (port->tty->index == PTITTY_MINOR_START)
+		console_stop(&pti_console);
+}
+
+static const struct tty_port_operations tty_port_ops = {
+	.activate = pti_port_activate,
+	.shutdown = pti_port_shutdown,
+};
+
+/*
+   Note the _probe() call sets everything up and ties the char and tty
+   to successfully detecting the PTI device on the pci bus.
+*/
+
+static int __devinit pti_pci_probe(struct pci_dev *pdev,
+		const struct pci_device_id *ent)
+{
+	int retval = -EINVAL;
+	int pci_bar = 1;
+
+	dev_dbg(&pdev->dev, "%s %s(%d): PTI PCI ID %04x:%04x\n", __FILE__,
+			__func__, __LINE__, pdev->vendor, pdev->device);
+
+	retval = misc_register(&pti_char_driver);
+	if (retval) {
+		pr_err("%s(%d): CHAR registration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+		return retval;
+	}
+
+	retval = pci_enable_device(pdev);
+	if (retval != 0) {
+		dev_err(&pdev->dev,
+			"%s: pci_enable_device() returned error %d\n",
+			__func__, retval);
+		return retval;
+	}
+
+	drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
+
+	if (drv_data == NULL) {
+		retval = -ENOMEM;
+		dev_err(&pdev->dev,
+			"%s(%d): kmalloc() returned NULL memory.\n",
+			__func__, __LINE__);
+		return retval;
+	}
+	drv_data->pti_addr = pci_resource_start(pdev, pci_bar);
+
+	retval = pci_request_region(pdev, pci_bar, dev_name(&pdev->dev));
+	if (retval != 0) {
+		dev_err(&pdev->dev,
+			"%s(%d): pci_request_region() returned error %d\n",
+			__func__, __LINE__, retval);
+		kfree(drv_data);
+		return retval;
+	}
+	drv_data->aperture_base = drv_data->pti_addr+APERTURE_14;
+	drv_data->pti_ioaddr =
+		ioremap_nocache((u32)drv_data->aperture_base,
+		APERTURE_LEN);
+	if (!drv_data->pti_ioaddr) {
+		pci_release_region(pdev, pci_bar);
+		retval = -ENOMEM;
+		kfree(drv_data);
+		return retval;
+	}
+
+	pci_set_drvdata(pdev, drv_data);
+
+	tty_port_init(&drv_data->port);
+	drv_data->port.ops = &tty_port_ops;
+
+	tty_register_device(pti_tty_driver, 0, &pdev->dev);
+	tty_register_device(pti_tty_driver, 1, &pdev->dev);
+
+	register_console(&pti_console);
+
+	return retval;
+}
+
+static struct pci_driver pti_pci_driver = {
+	.name		= PCINAME,
+	.id_table	= pci_ids,
+	.probe		= pti_pci_probe,
+	.remove		= pti_pci_remove,
+};
+
+/**
+ *
+ * pti_init():
+ *
+ * @return int __init: 0 for success, any other value error.
+ *
+ */
+static int __init pti_init(void)
+{
+	int retval = -EINVAL;
+
+	/* First register module as tty device */
+
+	pti_tty_driver = alloc_tty_driver(1);
+	if (pti_tty_driver == NULL) {
+		pr_err("%s(%d): Memory allocation failed for ptiTTY driver\n",
+			__func__, __LINE__);
+		return -ENOMEM;
+	}
+
+	pti_tty_driver->owner			= THIS_MODULE;
+	pti_tty_driver->magic			= TTY_DRIVER_MAGIC;
+	pti_tty_driver->driver_name		= DRIVERNAME;
+	pti_tty_driver->name			= TTYNAME;
+	pti_tty_driver->major			= 0;
+	pti_tty_driver->minor_start		= PTITTY_MINOR_START;
+	pti_tty_driver->minor_num		= PTITTY_MINOR_NUM;
+	pti_tty_driver->num			= PTITTY_MINOR_NUM;
+	pti_tty_driver->type			= TTY_DRIVER_TYPE_SYSTEM;
+	pti_tty_driver->subtype			= SYSTEM_TYPE_SYSCONS;
+	pti_tty_driver->flags			= TTY_DRIVER_REAL_RAW |
+						  TTY_DRIVER_DYNAMIC_DEV;
+	pti_tty_driver->init_termios		= tty_std_termios;
+
+	tty_set_operations(pti_tty_driver, &pti_tty_driver_ops);
+
+	retval = tty_register_driver(pti_tty_driver);
+	if (retval) {
+		pr_err("%s(%d): TTY registration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+
+		pti_tty_driver = NULL;
+		return retval;
+	}
+
+	retval = pci_register_driver(&pti_pci_driver);
+
+	if (retval) {
+		pr_err("%s(%d): PCI registration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+
+		tty_unregister_driver(pti_tty_driver);
+		pr_err("%s(%d): Unregistering TTY part of pti driver\n",
+			__func__, __LINE__);
+		pti_tty_driver = NULL;
+		return retval;
+	}
+
+	return retval;
+}
+
+/**
+ * pti_exit(): Unregisters this module as a tty and pci driver.
+ */
+static void __exit pti_exit(void)
+{
+	int retval;
+
+	tty_unregister_device(pti_tty_driver, 0);
+	tty_unregister_device(pti_tty_driver, 1);
+
+	retval = tty_unregister_driver(pti_tty_driver);
+	if (retval) {
+		pr_err("%s(%d): TTY unregistration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+	}
+
+	pci_unregister_driver(&pti_pci_driver);
+
+	retval = misc_deregister(&pti_char_driver);
+	if (retval) {
+		pr_err("%s(%d): CHAR unregistration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+	}
+
+	unregister_console(&pti_console);
+	return;
+}
+
+module_init(pti_init);
+module_exit(pti_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Ken Mills, Jay Freyensee");
+MODULE_DESCRIPTION("PTI Driver");
+
diff --git a/include/linux/pti.h b/include/linux/pti.h
new file mode 100644
index 0000000..94d05bc
--- /dev/null
+++ b/include/linux/pti.h
@@ -0,0 +1,39 @@
+/*
+ *  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 will allow other parts of the OS to use the
+ * interface to write out it's contents for debugging a mobile system.
+ */
+
+#ifndef PTI_H_
+#define PTI_H_
+
+/* basic structure used as a write address to the PTI HW */
+struct pti_masterchannel {
+	u8 master;
+	u8 channel;
+};
+
+/* the following functions are defined in misc/pti.c */
+void pti_writedata(struct pti_masterchannel *mc, u8 *buf, int count);
+struct pti_masterchannel *pti_request_masterchannel(u8 type);
+void pti_release_masterchannel(struct pti_masterchannel *mc);
+
+#endif /*PTI_H_*/
-- 
1.7.2.3

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[Randy Dunlap]

On Tue, 19 Apr 2011 15:58:08 -0700 james_p_freyensee@linux.intel.com wrote:


> diff --git a/drivers/misc/pti.c b/drivers/misc/pti.c
> new file mode 100644
> index 0000000..f3a2980
> --- /dev/null
> +++ b/drivers/misc/pti.c
> @@ -0,0 +1,898 @@
> +/*
> + *  pti.c - PTI driver for cJTAG data extration
> + *
> + *  Copyright (C) Intel 2010
> + *
> + * 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.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/sched.h>
> +#include <linux/interrupt.h>
> +#include <linux/console.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/tty.h>
> +#include <linux/tty_driver.h>
> +#include <linux/pci.h>
> +#include <linux/mutex.h>
> +#include <linux/miscdevice.h>
> +#include <linux/pti.h>
> +
> +#define DRIVERNAME		"pti"
> +#define PCINAME			"pciPTI"
> +#define TTYNAME			"ttyPTI"
> +#define CHARNAME		"pti"
> +#define PTITTY_MINOR_START	0
> +#define PTITTY_MINOR_NUM	2
> +#define MAX_APP_IDS		16   /* 128 channel ids / u8 bit size */
> +#define MAX_OS_IDS		16   /* 128 channel ids / u8 bit size */
> +#define MAX_MODEM_IDS		16   /* 128 channel ids / u8 bit size */
> +#define MODEM_BASE_ID		71   /* modem master ID address    */
> +#define CONTROL_ID		72   /* control master ID address  */
> +#define CONSOLE_ID		73   /* console master ID address  */
> +#define OS_BASE_ID		74   /* base OS master ID address  */
> +#define APP_BASE_ID		80   /* base App master ID address */
> +#define CONTROL_FRAME_LEN	32   /* PTI control frame maximum size */
> +#define USER_COPY_SIZE		8192 /* 8Kb buffer for user space copy */
> +#define APERTURE_14		0x3800000 /* offset to first OS write addr */
> +#define APERTURE_LEN		0x400000  /* address length */
> +
> +struct pti_tty {
> +	struct pti_masterchannel *mc;
> +};
> +
> +struct pti_dev {
> +	struct tty_port port;
> +	unsigned long pti_addr;
> +	unsigned long aperture_base;
> +	void __iomem *pti_ioaddr;
> +	u8 ia_app[MAX_APP_IDS];
> +	u8 ia_os[MAX_OS_IDS];
> +	u8 ia_modem[MAX_MODEM_IDS];
> +};
> +
> +/*
> +   This protects access to ia_app, ia_os, and ia_modem,
> +   which keeps track of channels allocated in
> +   an aperture write id.
> +*/

Use normal multi-line comment format:

/*
 * line1
 * line2
 */

> +static DEFINE_MUTEX(alloclock);
> +
> +static struct pci_device_id pci_ids[] __devinitconst = {
> +		{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x82B) },
> +		{0}
> +};
> +
> +static struct tty_driver *pti_tty_driver;
> +
> +static struct pti_dev *drv_data;
> +
> +static unsigned int pti_console_channel;
> +static unsigned int pti_control_channel;
> +
> +#define DTS 0x30		/* offset for last dword of a PTI message */
> +
> +/**
> + *  pti_write_to_aperture() - THE private write function to PTI HW.

THE ?

> + *  @mc: The 'aperture'. It's part of a write address that holds
> + *       a master and channel ID.
> + *  @buf: Data being written to the HW that will ultimately be seen
> + *        in a debugging tool (Fido, Lauterbach).
> + *  @len: Size of buffer.
> + *
> + *  Since each aperture is specified by a unique
> + *  master/channel ID, no two processes will be writing
> + *  to the same aperture at the same time so no lock is required. The
> + *  PTI-Output agent will send these out in the order that they arrived, and
> + *  thus, it will intermix these messages. The debug tool can then later
> + *  regroup the appropriate message segments together reconstituting each
> + *  message.
> + */
> +static void pti_write_to_aperture(struct pti_masterchannel *mc,
> +				  u8 *buf,
> +				  int len)
> +{
> +	int dwordcnt, final, i;
> +	u32 ptiword;
> +	u8 *p;
> +	u32 __iomem *aperture;
> +
> +	p = buf;
> +
> +	/*
> +	   calculate the aperture offset from the base using the master and
> +	   channel id's.
> +	*/

comment style (see Documentation/CodingStyle, section 8)


> +	aperture = drv_data->pti_ioaddr + (mc->master << 15)
> +		+ (mc->channel << 8);
> +
> +	dwordcnt = len >> 2;
> +	final = len - (dwordcnt << 2);		/* final = trailing bytes */
> +	if (final == 0 && dwordcnt != 0) {	/* always have a final dword */
> +		final += 4;
> +		dwordcnt--;
> +	}
> +
> +	for (i = 0; i < dwordcnt; i++) {
> +		ptiword = be32_to_cpu(*(u32 *)p);
> +		p += 4;
> +		iowrite32(ptiword, aperture);
> +	}
> +
> +	aperture += DTS;		/* adding DTS signals that is EOM */
> +
> +	ptiword = 0;
> +	for (i = 0; i < final; i++)
> +		ptiword |= *p++ << (24-(8*i));
> +
> +	iowrite32(ptiword, aperture);
> +	return;
> +}
> +
> +/**
> + *  pti_control_frame_built_and_sent() - control frame build and send function.
> + *  @mc: The master / channel structure on which the function built a control
> + *  frame.
> + *
> + *  To be able to post process the PTI contents on host side, a control frame
> + *  is added before sending any PTI content. So the host side knows on
> + *  each PTI frame the name of the thread using a dedicated master / channel.
> + *  This function builds this frame and sends it to a master ID CONTROL_ID.
> + *  The overhead is only 32 bytes since the driver only writes to HW
> + *  in 32 byte chunks.
> + */
> +
> +static void pti_control_frame_built_and_sent(struct pti_masterchannel *mc)
> +{
> +	struct pti_masterchannel mccontrol = {.master = CONTROL_ID,
> +					      .channel = 0};
> +	const char *control_format = "%3d %3d %s";
> +
> +	char comm[sizeof(current->comm) + 1];
> +	u8 control_frame[CONTROL_FRAME_LEN];
> +
> +	if (!in_interrupt())
> +		get_task_comm(comm, current);
> +	else
> +		strcpy(comm, "Interrupt");
> +
> +	/* Ensure our buffer is zero terminated */
> +	comm[sizeof(current->comm)] = 0;
> +
> +	mccontrol.channel = pti_control_channel;
> +	pti_control_channel = (pti_control_channel + 1) & 0x7f;
> +
> +	snprintf(control_frame, CONTROL_FRAME_LEN, control_format, mc->master,
> +		mc->channel, comm);
> +	pti_write_to_aperture(&mccontrol, control_frame, strlen(control_frame));
> +}
> +
> +/**
> + *  pti_write_full_frame_to_aperture() - high level function to write to PTI
> + *  @mc: The 'aperture'. It's part of a write address that holds
> + *       a master and channel ID.
> + *  @buf: Data being written to the HW that will ultimately be seen
> + *        in a debugging tool (Fido, Lauterbach).
> + *  @len: Size of buffer.
> + *
> + *  All threads sending data (either console, user space application, ...)
> + *  are calling the high level function to write to PTI meaning that it is
> + *  possible to add a control frame before sending the content.
> + */
> +static void pti_write_full_frame_to_aperture(struct pti_masterchannel *mc,
> +						const unsigned char *buf,
> +						int len)
> +{
> +	pti_control_frame_built_and_sent(mc);
> +	pti_write_to_aperture(mc, (u8 *)buf, len);
> +}
> +
> +
> +/**
> + * getID(): Allocate a master and channel ID.

 * getID() - Allocate a master and channel ID

> + *
> + * @IDarray:

needs explanatory text

> + * @max_IDS: The max amount of available write IDs to use.
> + * @baseID:  The starting SW channel ID, based on the Intel
> + *           PTI arch.
> + *
> + * @return: pti_masterchannel struct containing master, channel ID address,

No '@' on "return".


> + * or 0 for error.
> + *
> + * Each bit in the arrays ia_app and ia_os correspond to a master and
> + * channel id. The bit is one if the id is taken and 0 if free. For
> + * every master there are 128 channel id's.
> + */
> +static struct pti_masterchannel *getID(u8 *IDarray, int max_IDS, int baseID)
> +{
> +	struct pti_masterchannel *mc;
> +	int i, j, mask;
> +
> +	mc = kmalloc(sizeof(struct pti_masterchannel), GFP_KERNEL);
> +	if (mc == NULL)
> +		return NULL;
> +
> +	/* look for a byte with a free bit */
> +	for (i = 0; i < max_IDS; i++)
> +		if (IDarray[i] != 0xff)
> +			break;
> +	if (i == max_IDS) {
> +		kfree(mc);
> +		return NULL;
> +	}
> +	/* find the bit in the 128 possible channel opportunities */
> +	mask = 0x80;
> +	for (j = 0; j < 8; j++) {
> +		if ((IDarray[i] & mask) == 0)
> +			break;
> +		mask >>= 1;
> +	}
> +
> +	/* grab it */
> +	IDarray[i] |= mask;
> +	mc->master  = baseID;
> +	mc->channel = ((i & 0xf)<<3) + j;
> +	/* write new master Id / channel Id allocation to channel control */
> +	pti_control_frame_built_and_sent(mc);
> +	return mc;
> +}
> +
> +/*
> +	The following three functions:
> +	pti_request_mastercahannel(), mipi_release_masterchannel()
> +	and pti_writedata() are an API for other kernel drivers to
> +	access PTI.
> +*/

multi-line comment style.

> +
> +/**
> + * pti_request_masterchannel() - Kernel API function used to allocate
> + *                                a master, channel ID address to write to
> + *                                PTI HW.
> + * @type: 0- request Application  master, channel aperture ID write address.
> + *        1- request OS master, channel aperture ID write address.
> + *        2- request Modem master, channel aperture ID write
> + *           address.
> + *        Other values, error.
> + * @return: pti_masterchannel struct or 0 for error.

No '@' on "return".

> + *
> + */
> +struct pti_masterchannel *pti_request_masterchannel(u8 type)
> +{
> +	struct pti_masterchannel *mc;
> +
> +	mutex_lock(&alloclock);
> +
> +	switch (type) {
> +
> +	case 0:
> +		mc = getID(drv_data->ia_app, MAX_APP_IDS, APP_BASE_ID);
> +		break;
> +
> +	case 1:
> +		mc = getID(drv_data->ia_os, MAX_OS_IDS, OS_BASE_ID);
> +		break;
> +
> +	case 2:
> +		mc = getID(drv_data->ia_modem, MAX_MODEM_IDS, MODEM_BASE_ID);
> +		break;
> +	default:
> +		mc = NULL;
> +	}
> +
> +	mutex_unlock(&alloclock);
> +	return mc;
> +}
> +EXPORT_SYMBOL_GPL(pti_request_masterchannel);
> +
> +/**
> + * pti_release_masterchannel() - Kernel API function used to release
> + *                                a master, channel ID address
> + *                                used to write to PTI HW.
> + * @mc: master, channel apeture ID address to be released.
> + *
> + */
> +void pti_release_masterchannel(struct pti_masterchannel *mc)
> +{
> +	u8 master, channel, i;
> +
> +	mutex_lock(&alloclock);
> +
> +	if (mc) {
> +		master = mc->master;
> +		channel = mc->channel;
> +
> +		if (master == APP_BASE_ID) {
> +			i = channel >> 3;
> +			drv_data->ia_app[i] &=  ~(0x80>>(channel & 0x7));
> +		} else if (master == OS_BASE_ID) {
> +			i = channel >> 3;
> +			drv_data->ia_os[i] &= ~(0x80>>(channel & 0x7));
> +		} else {
> +			i = channel >> 3;
> +			drv_data->ia_modem[i] &= ~(0x80>>(channel & 0x7));
> +		}
> +
> +		kfree(mc);
> +	}
> +
> +	mutex_unlock(&alloclock);
> +}
> +EXPORT_SYMBOL_GPL(pti_release_masterchannel);
> +
> +/**
> + * pti_writedata() - Kernel API function used to write trace
> + *                   debugging data to PTI HW.
> + *
> + * @mc:    Master, channel aperture ID address to write to.
> + *         Null value will return with no write occurring.
> + * @buf:   Trace debuging data to write to the PTI HW.
> + *         Null value will return with no write occurring.
> + * @count: Size of buf. Value of 0 or a negative number will
> + *         retrn with no write occuring.

	      return with no write occurring.

or maybe the @count/@len parameters should be size_t so that they cannot
be negative.

> + */
> +void pti_writedata(struct pti_masterchannel *mc, u8 *buf, int count)
> +{
> +	/*
> +	   since this function is exported, this is treated like an
> +	   API function, thus, all parameters should
> +	   be checked for validity.
> +	*/

comment style.

> +	if ((mc != NULL) && (buf != NULL) && (count > 0))
> +		pti_write_to_aperture(mc, buf, count);
> +	return;
> +}
> +EXPORT_SYMBOL_GPL(pti_writedata);
> +
> +static void __devexit pti_pci_remove(struct pci_dev *pdev)
> +{
> +	struct pti_dev *drv_data;
> +
> +	drv_data = pci_get_drvdata(pdev);
> +	if (drv_data != NULL) {
> +		pci_iounmap(pdev, drv_data->pti_ioaddr);
> +		pci_set_drvdata(pdev, NULL);
> +		kfree(drv_data);
> +		pci_release_region(pdev, 1);
> +		pci_disable_device(pdev);
> +	}
> +}
> +
> +/*
> +   for the tty_driver_*() basic function descriptions, see tty_driver.h.
> +   Specific header comments made for PTI-related specifics.
> +*/

comment style.

> +
> +/**
> + * pti_tty_driver_open()- Open an Application master, channel aperture
> + * ID to the PTI device via tty device.
> + *
> + * @param tty: tty interface.
> + * @param filp: filp interface pased to tty_port_open() call.

drop "param".  Just use:

 * @tty: <text>
 * @filp: <text>

> + *
> + * @return int : Success = 0, otherwise fail.

No '@' on "return".


> + *
> + * The main purpose of using the tty device interface is for
> + * each tty port to have a unique PTI write aperture.  In an
> + * example use case, ttyPTI0 gets syslogd and an APP aperture
> + * ID and ttyPTI1 is where the n_tracesink ldisc hooks to route
> + * modem messages into PTI.  Modem trace data does not have to
> + * go to ttyPTI1, but ttyPTI0 and ttyPTI1 do need to be distinct
> + * master IDs.  These messages go through the PTI HW and out of
> + * the handheld platform and to the Fido/Lauterbach device.
> + */
> +static int pti_tty_driver_open(struct tty_struct *tty, struct file *filp)
> +{
> +	int ret = 0;
> +
> +	/*
> +	   we actually want to allocate a new channel per open, per
> +	   system arch.  HW gives more than plenty channels for a single
> +	   system task to have its own channel to write trace data. This
> +	   also removes a locking requirement for the actual write
> +	   procedure.
> +	*/

comment style.

> +	ret = tty_port_open(&drv_data->port, tty, filp);
> +
> +	return ret;
> +}
> +
> +/**
> + * pti_tty_driver_close()- close tty device and release Application
> + * master, channel aperture ID to the PTI device via tty device.
> + *
> + * @param tty: tty interface.
> + * @param filp: filp interface pased to tty_port_close() call.

Incorrect kernel-doc notation.  See Documentation/kernel-doc-nano-HOWTO.txt.

> + *
> + * The main purpose of using the tty device interface is to route
> + * syslog daemon messages to the PTI HW and out of the handheld platform
> + * and to the Fido/Lauterbach device.
> + */
> +static void pti_tty_driver_close(struct tty_struct *tty, struct file *filp)
> +{
> +	tty_port_close(&drv_data->port, tty, filp);
> +
> +	return;
> +}
> +
> +static int pti_tty_install(struct tty_driver *driver, struct tty_struct *tty)
> +{
> +	int idx = tty->index;
> +	struct pti_tty *pti_tty_data;
> +	struct pti_masterchannel *mc;
> +	int ret = tty_init_termios(tty);
> +
> +	if (ret == 0) {
> +		tty_driver_kref_get(driver);
> +		tty->count++;
> +		driver->ttys[idx] = tty;
> +
> +		pti_tty_data = kmalloc(sizeof(struct pti_tty), GFP_KERNEL);
> +		if (pti_tty_data == NULL)
> +			return -ENOMEM;
> +
> +		tty->driver_data = pti_tty_data;
> +
> +		if (idx == PTITTY_MINOR_START)
> +			mc = pti_request_masterchannel(0);
> +		else
> +			mc = pti_request_masterchannel(2);
> +
> +		if (mc == NULL)
> +			return -ENXIO;
> +
> +		pti_tty_data->mc = mc;
> +	}
> +
> +	return ret;
> +}
> +
> +static void pti_tty_cleanup(struct tty_struct *tty)
> +{
> +	struct pti_tty *pti_tty_data;
> +	struct pti_masterchannel *mc;
> +
> +	pti_tty_data = tty->driver_data;
> +
> +	if (pti_tty_data != NULL) {
> +		mc = pti_tty_data->mc;
> +		pti_release_masterchannel(mc);
> +		pti_tty_data->mc = NULL;
> +	}
> +
> +	if (pti_tty_data != NULL)
> +		kfree(pti_tty_data);
> +
> +	tty->driver_data = NULL;
> +}
> +
> +/**
> + * pti_tty_driver_write():  Write trace debugging data through the char

 * pti_tty_driver_write() - <text>

> + * interface to the PTI HW.  Part of the misc device implementation.
> + *
> + * @param filp: Contains private data which is used to obtain
> + *              master, channel write ID.
> + * @param data: trace data to be written.
> + * @param len:  # of byte to write.
> + * @return int : # of bytes written, or error.

Fix kernel-doc notation.  again.  :(

> + */
> +static int pti_tty_driver_write(struct tty_struct *tty,
> +	const unsigned char *buf, int len)
> +{
> +	struct pti_masterchannel *mc;
> +	struct pti_tty *pti_tty_data;
> +
> +	pti_tty_data = tty->driver_data;
> +	mc = pti_tty_data->mc;
> +	pti_write_to_aperture(mc, (u8 *)buf, len);
> +
> +	return len;
> +}
> +
> +static int pti_tty_write_room(struct tty_struct *tty)
> +{
> +	return 2048;
> +}
> +
> +/**
> + * pti_char_open()- Open an Application master, channel aperture
> + * ID to the PTI device. Part of the misc device implementation.
> + *
> + * @param inode: not used.
> + * @param filp: Output- will have a masterchannel struct set containing
> + * the allocated application PTI aperture write address.
> + *
> + * @return int : Success = 0, otherwise fail.  As of right now,
> + *         it is not sure what needs to really be initialized
> + *         for open(), so it always returns 0.

Fix kernel-doc notation.

> + */
> +static int pti_char_open(struct inode *inode, struct file *filp)
> +{
> +	struct pti_masterchannel *mc;
> +
> +	mc = pti_request_masterchannel(0);
> +	if (mc == NULL)
> +		return -ENOMEM;
> +	filp->private_data = mc;
> +	return 0;
> +}
> +
> +/**
> + * pti_char_release()-  Close a char channel to the PTI device. Part
> + * of the misc device implementation.
> + *
> + * @param inode: Not used in this implementaiton.
> + * @param filp: Contains private_data that contains the master, channel
> + * ID to be released by the PTI device.
> + *
> + * @return int : Success = 0

fix kernel-doc notation.

> + */
> +static int pti_char_release(struct inode *inode, struct file *filp)
> +{
> +	pti_release_masterchannel(filp->private_data);
> +	return 0;
> +}
> +
> +/**
> + * pti_char_write():  Write trace debugging data through the char

use '-' instead of ':'

> + * interface to the PTI HW.  Part of the misc device implementation.
> + *
> + * @param filp: Contains private data which is used to obtain
> + *              master, channel write ID.
> + * @param data: trace data to be written.
> + * @param len:  # of byte to write.
> + * @param ppose: Not used in this function implementation.
> + * @return int : # of bytes written, or error.

Fix kernel-doc notation.

> + *
> + * Notes: From side discussions with Alan Cox and experimenting
> + * with PTI debug HW like Nokia's Fido box and Lauterbach
> + * devices, 8192 byte write buffer used by USER_COPY_SIZE was
> + * deemed an appropriate size for this type of usage with
> + * debugging HW.
> + */
> +static ssize_t pti_char_write(struct file *filp, const char __user *data,
> +			      size_t len, loff_t *ppose)
> +{
> +	struct pti_masterchannel *mc;
> +	void *kbuf;
> +	const char __user *tmp;
> +	size_t size = USER_COPY_SIZE, n = 0;
> +
> +	tmp = data;
> +	mc = filp->private_data;
> +
> +	kbuf = kmalloc(size, GFP_KERNEL);
> +	if (kbuf == NULL)  {
> +		pr_err("%s(%d): buf allocation failed\n",
> +			__func__, __LINE__);
> +		return 0;
> +	}
> +
> +	do {
> +		if (len - n > USER_COPY_SIZE)
> +			size = USER_COPY_SIZE;
> +		else
> +			size = len - n;
> +
> +		if (copy_from_user(kbuf, tmp, size)) {
> +			kfree(kbuf);
> +			return n ? n : -EFAULT;
> +		}
> +
> +		pti_write_to_aperture(mc, kbuf, size);
> +		n  += size;
> +		tmp += size;
> +
> +	} while (len > n);
> +
> +	kfree(kbuf);
> +	kbuf = NULL;
> +
> +	return len;
> +}
> +
> +static const struct tty_operations pti_tty_driver_ops = {
> +	.open		= pti_tty_driver_open,
> +	.close		= pti_tty_driver_close,
> +	.write		= pti_tty_driver_write,
> +	.write_room	= pti_tty_write_room,
> +	.install	= pti_tty_install,
> +	.cleanup	= pti_tty_cleanup
> +};
> +
> +static const struct file_operations pti_char_driver_ops = {
> +	.owner		= THIS_MODULE,
> +	.write		= pti_char_write,
> +	.open		= pti_char_open,
> +	.release	= pti_char_release,
> +};
> +
> +static struct miscdevice pti_char_driver = {
> +	.minor		= MISC_DYNAMIC_MINOR,
> +	.name		= CHARNAME,
> +	.fops		= &pti_char_driver_ops
> +};
> +
> +static void pti_console_write(struct console *c, const char *buf, unsigned len)
> +{
> +	static struct pti_masterchannel mc = {.master  = CONSOLE_ID,
> +					      .channel = 0};
> +
> +	mc.channel = pti_console_channel;
> +	pti_console_channel = (pti_console_channel + 1) & 0x7f;
> +
> +	pti_write_full_frame_to_aperture(&mc, buf, len);
> +}
> +
> +static struct tty_driver *pti_console_device(struct console *c, int *index)
> +{
> +	*index = c->index;
> +	return pti_tty_driver;
> +}
> +
> +static int pti_console_setup(struct console *c, char *opts)
> +{
> +	pti_console_channel = 0;
> +	pti_control_channel = 0;
> +	return 0;
> +}
> +
> +/* pti_console struct, used to capture OS printk()'s and shift
> + * out to the PTI device for debugging.  This cannot be
> + * enabled upon boot because of the possibility of eating
> + * any serial console printk's (race condition discovered).
> + * The console should be enabled upon when the tty port is
> + * used for the first time.  Since the primary purpose for
> + * the tty port is to hook up syslog to it, the tty port
> + * will be open for a really long time.
> + */

fix long comment style.

> +static struct console pti_console = {
> +	.name		= TTYNAME,
> +	.write		= pti_console_write,
> +	.device		= pti_console_device,
> +	.setup		= pti_console_setup,
> +	.flags		= CON_PRINTBUFFER,
> +	.index		= 0,
> +};
> +
> +/**
> + * pti_port_activate(): Used to start/initialize any items upon

use '-' instead of ':'

> + * first opening of tty_port().
> + *
> + * @param port- The tty port number of the PTI device.
> + * @param tty-  The tty struct associated with this device.
> + *
> + * @return int - Always returns 0.

fix kernel-doc notation.

> + *
> + * Notes: The primary purpose of the PTI tty port 0 is to hook
> + * the syslog daemon to it; thus this port will be open for a
> + * very long time.
> + */
> +static int pti_port_activate(struct tty_port *port, struct tty_struct *tty)
> +{
> +	if (port->tty->index == PTITTY_MINOR_START)
> +		console_start(&pti_console);
> +	return 0;
> +}
> +
> +/**
> + * pti_port_shutdown(): Used to stop/shutdown any items upon the

use - instead of :

> + * last tty port close.
> + *
> + * @param port- The tty port number of the PTI device.

fix kernel-doc notation.

> + *
> + * Notes: The primary purpose of the PTI tty port 0 is to hook
> + * the syslog daemon to it; thus this port will be open for a
> + * very long time.
> + */
> +static void pti_port_shutdown(struct tty_port *port)
> +{
> +	if (port->tty->index == PTITTY_MINOR_START)
> +		console_stop(&pti_console);
> +}
> +
> +static const struct tty_port_operations tty_port_ops = {
> +	.activate = pti_port_activate,
> +	.shutdown = pti_port_shutdown,
> +};
> +
> +/*
> +   Note the _probe() call sets everything up and ties the char and tty
> +   to successfully detecting the PTI device on the pci bus.
> +*/

fix long comment style.

> +
> +static int __devinit pti_pci_probe(struct pci_dev *pdev,
> +		const struct pci_device_id *ent)
> +{
> +	int retval = -EINVAL;
> +	int pci_bar = 1;
> +
> +	dev_dbg(&pdev->dev, "%s %s(%d): PTI PCI ID %04x:%04x\n", __FILE__,
> +			__func__, __LINE__, pdev->vendor, pdev->device);
> +
> +	retval = misc_register(&pti_char_driver);
> +	if (retval) {
> +		pr_err("%s(%d): CHAR registration failed of pti driver\n",
> +			__func__, __LINE__);
> +		pr_err("%s(%d): Error value returned: %d\n",
> +			__func__, __LINE__, retval);
> +		return retval;
> +	}
> +
> +	retval = pci_enable_device(pdev);
> +	if (retval != 0) {
> +		dev_err(&pdev->dev,
> +			"%s: pci_enable_device() returned error %d\n",
> +			__func__, retval);
> +		return retval;
> +	}
> +
> +	drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
> +
> +	if (drv_data == NULL) {
> +		retval = -ENOMEM;
> +		dev_err(&pdev->dev,
> +			"%s(%d): kmalloc() returned NULL memory.\n",
> +			__func__, __LINE__);
> +		return retval;
> +	}
> +	drv_data->pti_addr = pci_resource_start(pdev, pci_bar);
> +
> +	retval = pci_request_region(pdev, pci_bar, dev_name(&pdev->dev));
> +	if (retval != 0) {
> +		dev_err(&pdev->dev,
> +			"%s(%d): pci_request_region() returned error %d\n",
> +			__func__, __LINE__, retval);
> +		kfree(drv_data);
> +		return retval;
> +	}
> +	drv_data->aperture_base = drv_data->pti_addr+APERTURE_14;
> +	drv_data->pti_ioaddr =
> +		ioremap_nocache((u32)drv_data->aperture_base,
> +		APERTURE_LEN);
> +	if (!drv_data->pti_ioaddr) {
> +		pci_release_region(pdev, pci_bar);
> +		retval = -ENOMEM;
> +		kfree(drv_data);
> +		return retval;
> +	}
> +
> +	pci_set_drvdata(pdev, drv_data);
> +
> +	tty_port_init(&drv_data->port);
> +	drv_data->port.ops = &tty_port_ops;
> +
> +	tty_register_device(pti_tty_driver, 0, &pdev->dev);
> +	tty_register_device(pti_tty_driver, 1, &pdev->dev);
> +
> +	register_console(&pti_console);
> +
> +	return retval;
> +}
> +
> +static struct pci_driver pti_pci_driver = {
> +	.name		= PCINAME,
> +	.id_table	= pci_ids,
> +	.probe		= pti_pci_probe,
> +	.remove		= pti_pci_remove,
> +};
> +
> +/**
> + *
> + * pti_init():

Needs short function summary on line above.

> + *
> + * @return int __init: 0 for success, any other value error.

fix kernel-doc notation.

> + *
> + */
> +static int __init pti_init(void)
> +{
> +	int retval = -EINVAL;
> +
> +	/* First register module as tty device */
> +
> +	pti_tty_driver = alloc_tty_driver(1);
> +	if (pti_tty_driver == NULL) {
> +		pr_err("%s(%d): Memory allocation failed for ptiTTY driver\n",
> +			__func__, __LINE__);
> +		return -ENOMEM;
> +	}
> +
> +	pti_tty_driver->owner			= THIS_MODULE;
> +	pti_tty_driver->magic			= TTY_DRIVER_MAGIC;
> +	pti_tty_driver->driver_name		= DRIVERNAME;
> +	pti_tty_driver->name			= TTYNAME;
> +	pti_tty_driver->major			= 0;
> +	pti_tty_driver->minor_start		= PTITTY_MINOR_START;
> +	pti_tty_driver->minor_num		= PTITTY_MINOR_NUM;
> +	pti_tty_driver->num			= PTITTY_MINOR_NUM;
> +	pti_tty_driver->type			= TTY_DRIVER_TYPE_SYSTEM;
> +	pti_tty_driver->subtype			= SYSTEM_TYPE_SYSCONS;
> +	pti_tty_driver->flags			= TTY_DRIVER_REAL_RAW |
> +						  TTY_DRIVER_DYNAMIC_DEV;
> +	pti_tty_driver->init_termios		= tty_std_termios;
> +
> +	tty_set_operations(pti_tty_driver, &pti_tty_driver_ops);
> +
> +	retval = tty_register_driver(pti_tty_driver);
> +	if (retval) {
> +		pr_err("%s(%d): TTY registration failed of pti driver\n",
> +			__func__, __LINE__);
> +		pr_err("%s(%d): Error value returned: %d\n",
> +			__func__, __LINE__, retval);
> +
> +		pti_tty_driver = NULL;
> +		return retval;
> +	}
> +
> +	retval = pci_register_driver(&pti_pci_driver);
> +
> +	if (retval) {
> +		pr_err("%s(%d): PCI registration failed of pti driver\n",
> +			__func__, __LINE__);
> +		pr_err("%s(%d): Error value returned: %d\n",
> +			__func__, __LINE__, retval);
> +
> +		tty_unregister_driver(pti_tty_driver);
> +		pr_err("%s(%d): Unregistering TTY part of pti driver\n",
> +			__func__, __LINE__);
> +		pti_tty_driver = NULL;
> +		return retval;
> +	}
> +
> +	return retval;
> +}
> +
> +/**
> + * pti_exit(): Unregisters this module as a tty and pci driver.

use - instead of :

> + */
> +static void __exit pti_exit(void)
> +{
> +	int retval;
> +
> +	tty_unregister_device(pti_tty_driver, 0);
> +	tty_unregister_device(pti_tty_driver, 1);
> +
> +	retval = tty_unregister_driver(pti_tty_driver);
> +	if (retval) {
> +		pr_err("%s(%d): TTY unregistration failed of pti driver\n",
> +			__func__, __LINE__);
> +		pr_err("%s(%d): Error value returned: %d\n",
> +			__func__, __LINE__, retval);
> +	}
> +
> +	pci_unregister_driver(&pti_pci_driver);
> +
> +	retval = misc_deregister(&pti_char_driver);
> +	if (retval) {
> +		pr_err("%s(%d): CHAR unregistration failed of pti driver\n",
> +			__func__, __LINE__);
> +		pr_err("%s(%d): Error value returned: %d\n",
> +			__func__, __LINE__, retval);
> +	}
> +
> +	unregister_console(&pti_console);
> +	return;
> +}
> +
> +module_init(pti_init);
> +module_exit(pti_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Ken Mills, Jay Freyensee");
> +MODULE_DESCRIPTION("PTI Driver");


---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[David Rientjes]

On Tue, 19 Apr 2011, james_p_freyensee@linux.intel.com wrote:

> +static void pti_control_frame_built_and_sent(struct pti_masterchannel *mc)
> +{
> +	struct pti_masterchannel mccontrol = {.master = CONTROL_ID,
> +					      .channel = 0};
> +	const char *control_format = "%3d %3d %s";
> +
> +	char comm[sizeof(current->comm) + 1];
> +	u8 control_frame[CONTROL_FRAME_LEN];
> +
> +	if (!in_interrupt())
> +		get_task_comm(comm, current);
> +	else
> +		strcpy(comm, "Interrupt");
> +
> +	/* Ensure our buffer is zero terminated */
> +	comm[sizeof(current->comm)] = 0;
> +

You definitely need to use get_task_comm() here, but that means you can't 
allocate char comm[] on the stack with anything but TASK_COMM_LEN, which 
is small enough that it shouldn't be an issue.  Otherwise there's nothing 
protecting sizeof(current->comm) from changing without holding 
task_lock(current).

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[Alan Cox]

> is small enough that it shouldn't be an issue.  Otherwise there's nothing 
> protecting sizeof(current->comm) from changing without holding 
> task_lock(current).

The C language definition for one - sizeof() is a constant at compile time

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[J Freyensee]

On Wed, 2011-04-20 at 10:46 +0100, Alan Cox wrote:
> > is small enough that it shouldn't be an issue.  Otherwise there's nothing 
> > protecting sizeof(current->comm) from changing without holding 
> > task_lock(current).
> 
> The C language definition for one - sizeof() is a constant at compile time

K, thanks, I'll look at re-working these couple lines of code.

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[J Freyensee]

On Tue, 2011-04-19 at 16:15 -0700, Randy Dunlap wrote:

A couple more comments below.

> On Tue, 19 Apr 2011 15:58:08 -0700 james_p_freyensee@linux.intel.com wrote:
> 
> 
> > diff --git a/drivers/misc/pti.c b/drivers/misc/pti.c
> > new file mode 100644
> > index 0000000..f3a2980
> > --- /dev/null
> > +++ b/drivers/misc/pti.c
> > @@ -0,0 +1,898 @@
> > +/*
> > + *  pti.c - PTI driver for cJTAG data extration
> > + *
> > + *  Copyright (C) Intel 2010
> > + *
> > + * 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.
> > + */
> > +
> > +#include <linux/init.h>
> > +#include <linux/sched.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/console.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/tty.h>
> > +#include <linux/tty_driver.h>
> > +#include <linux/pci.h>
> > +#include <linux/mutex.h>
> > +#include <linux/miscdevice.h>
> > +#include <linux/pti.h>
> > +
> > +#define DRIVERNAME		"pti"
> > +#define PCINAME			"pciPTI"
> > +#define TTYNAME			"ttyPTI"
> > +#define CHARNAME		"pti"
> > +#define PTITTY_MINOR_START	0
> > +#define PTITTY_MINOR_NUM	2
> > +#define MAX_APP_IDS		16   /* 128 channel ids / u8 bit size */
> > +#define MAX_OS_IDS		16   /* 128 channel ids / u8 bit size */
> > +#define MAX_MODEM_IDS		16   /* 128 channel ids / u8 bit size */
> > +#define MODEM_BASE_ID		71   /* modem master ID address    */
> > +#define CONTROL_ID		72   /* control master ID address  */
> > +#define CONSOLE_ID		73   /* console master ID address  */
> > +#define OS_BASE_ID		74   /* base OS master ID address  */
> > +#define APP_BASE_ID		80   /* base App master ID address */
> > +#define CONTROL_FRAME_LEN	32   /* PTI control frame maximum size */
> > +#define USER_COPY_SIZE		8192 /* 8Kb buffer for user space copy */
> > +#define APERTURE_14		0x3800000 /* offset to first OS write addr */
> > +#define APERTURE_LEN		0x400000  /* address length */
> > +
> > +struct pti_tty {
> > +	struct pti_masterchannel *mc;
> > +};
> > +
> > +struct pti_dev {
> > +	struct tty_port port;
> > +	unsigned long pti_addr;
> > +	unsigned long aperture_base;
> > +	void __iomem *pti_ioaddr;
> > +	u8 ia_app[MAX_APP_IDS];
> > +	u8 ia_os[MAX_OS_IDS];
> > +	u8 ia_modem[MAX_MODEM_IDS];
> > +};
> > +
> > +/*
> > +   This protects access to ia_app, ia_os, and ia_modem,
> > +   which keeps track of channels allocated in
> > +   an aperture write id.
> > +*/
> 
> Use normal multi-line comment format:
> 
> /*
>  * line1
>  * line2
>  */
> 
> > +static DEFINE_MUTEX(alloclock);
> > +
> > +static struct pci_device_id pci_ids[] __devinitconst = {
> > +		{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x82B) },
> > +		{0}
> > +};
> > +
> > +static struct tty_driver *pti_tty_driver;
> > +
> > +static struct pti_dev *drv_data;
> > +
> > +static unsigned int pti_console_channel;
> > +static unsigned int pti_control_channel;
> > +
> > +#define DTS 0x30		/* offset for last dword of a PTI message */
> > +
> > +/**
> > + *  pti_write_to_aperture() - THE private write function to PTI HW.
> 
> THE ?
> 
> > + *  @mc: The 'aperture'. It's part of a write address that holds
> > + *       a master and channel ID.
> > + *  @buf: Data being written to the HW that will ultimately be seen
> > + *        in a debugging tool (Fido, Lauterbach).
> > + *  @len: Size of buffer.
> > + *
> > + *  Since each aperture is specified by a unique
> > + *  master/channel ID, no two processes will be writing
> > + *  to the same aperture at the same time so no lock is required. The
> > + *  PTI-Output agent will send these out in the order that they arrived, and
> > + *  thus, it will intermix these messages. The debug tool can then later
> > + *  regroup the appropriate message segments together reconstituting each
> > + *  message.
> > + */
> > +static void pti_write_to_aperture(struct pti_masterchannel *mc,
> > +				  u8 *buf,
> > +				  int len)
> > +{
> > +	int dwordcnt, final, i;
> > +	u32 ptiword;
> > +	u8 *p;
> > +	u32 __iomem *aperture;
> > +
> > +	p = buf;
> > +
> > +	/*
> > +	   calculate the aperture offset from the base using the master and
> > +	   channel id's.
> > +	*/
> 
> comment style (see Documentation/CodingStyle, section 8)
> 
> 
> > +	aperture = drv_data->pti_ioaddr + (mc->master << 15)
> > +		+ (mc->channel << 8);
> > +
> > +	dwordcnt = len >> 2;
> > +	final = len - (dwordcnt << 2);		/* final = trailing bytes */
> > +	if (final == 0 && dwordcnt != 0) {	/* always have a final dword */
> > +		final += 4;
> > +		dwordcnt--;
> > +	}
> > +
> > +	for (i = 0; i < dwordcnt; i++) {
> > +		ptiword = be32_to_cpu(*(u32 *)p);
> > +		p += 4;
> > +		iowrite32(ptiword, aperture);
> > +	}
> > +
> > +	aperture += DTS;		/* adding DTS signals that is EOM */
> > +
> > +	ptiword = 0;
> > +	for (i = 0; i < final; i++)
> > +		ptiword |= *p++ << (24-(8*i));
> > +
> > +	iowrite32(ptiword, aperture);
> > +	return;
> > +}
> > +
> > +/**
> > + *  pti_control_frame_built_and_sent() - control frame build and send function.
> > + *  @mc: The master / channel structure on which the function built a control
> > + *  frame.
> > + *
> > + *  To be able to post process the PTI contents on host side, a control frame
> > + *  is added before sending any PTI content. So the host side knows on
> > + *  each PTI frame the name of the thread using a dedicated master / channel.
> > + *  This function builds this frame and sends it to a master ID CONTROL_ID.
> > + *  The overhead is only 32 bytes since the driver only writes to HW
> > + *  in 32 byte chunks.
> > + */
> > +
> > +static void pti_control_frame_built_and_sent(struct pti_masterchannel *mc)
> > +{
> > +	struct pti_masterchannel mccontrol = {.master = CONTROL_ID,
> > +					      .channel = 0};
> > +	const char *control_format = "%3d %3d %s";
> > +
> > +	char comm[sizeof(current->comm) + 1];
> > +	u8 control_frame[CONTROL_FRAME_LEN];
> > +
> > +	if (!in_interrupt())
> > +		get_task_comm(comm, current);
> > +	else
> > +		strcpy(comm, "Interrupt");
> > +
> > +	/* Ensure our buffer is zero terminated */
> > +	comm[sizeof(current->comm)] = 0;
> > +
> > +	mccontrol.channel = pti_control_channel;
> > +	pti_control_channel = (pti_control_channel + 1) & 0x7f;
> > +
> > +	snprintf(control_frame, CONTROL_FRAME_LEN, control_format, mc->master,
> > +		mc->channel, comm);
> > +	pti_write_to_aperture(&mccontrol, control_frame, strlen(control_frame));
> > +}
> > +
> > +/**
> > + *  pti_write_full_frame_to_aperture() - high level function to write to PTI
> > + *  @mc: The 'aperture'. It's part of a write address that holds
> > + *       a master and channel ID.
> > + *  @buf: Data being written to the HW that will ultimately be seen
> > + *        in a debugging tool (Fido, Lauterbach).
> > + *  @len: Size of buffer.
> > + *
> > + *  All threads sending data (either console, user space application, ...)
> > + *  are calling the high level function to write to PTI meaning that it is
> > + *  possible to add a control frame before sending the content.
> > + */
> > +static void pti_write_full_frame_to_aperture(struct pti_masterchannel *mc,
> > +						const unsigned char *buf,
> > +						int len)
> > +{
> > +	pti_control_frame_built_and_sent(mc);
> > +	pti_write_to_aperture(mc, (u8 *)buf, len);
> > +}
> > +
> > +
> > +/**
> > + * getID(): Allocate a master and channel ID.
> 
>  * getID() - Allocate a master and channel ID
> 
> > + *
> > + * @IDarray:
> 
> needs explanatory text
> 
> > + * @max_IDS: The max amount of available write IDs to use.
> > + * @baseID:  The starting SW channel ID, based on the Intel
> > + *           PTI arch.
> > + *
> > + * @return: pti_masterchannel struct containing master, channel ID address,
> 
> No '@' on "return".

Why no '@' on 'return' when just by doing a 'grep -Ri "@return" drivers/
| wc -l' I count 369 examples of '@return' being used already in the
kernel?  It looks like an acceptable format to me.

> 
> 
> > + * or 0 for error.
> > + *
> > + * Each bit in the arrays ia_app and ia_os correspond to a master and
> > + * channel id. The bit is one if the id is taken and 0 if free. For
> > + * every master there are 128 channel id's.
> > + */
> > +static struct pti_masterchannel *getID(u8 *IDarray, int max_IDS, int baseID)
> > +{
> > +	struct pti_masterchannel *mc;
> > +	int i, j, mask;
> > +
> > +	mc = kmalloc(sizeof(struct pti_masterchannel), GFP_KERNEL);
> > +	if (mc == NULL)
> > +		return NULL;
> > +
> > +	/* look for a byte with a free bit */
> > +	for (i = 0; i < max_IDS; i++)
> > +		if (IDarray[i] != 0xff)
> > +			break;
> > +	if (i == max_IDS) {
> > +		kfree(mc);
> > +		return NULL;
> > +	}
> > +	/* find the bit in the 128 possible channel opportunities */
> > +	mask = 0x80;
> > +	for (j = 0; j < 8; j++) {
> > +		if ((IDarray[i] & mask) == 0)
> > +			break;
> > +		mask >>= 1;
> > +	}
> > +
> > +	/* grab it */
> > +	IDarray[i] |= mask;
> > +	mc->master  = baseID;
> > +	mc->channel = ((i & 0xf)<<3) + j;
> > +	/* write new master Id / channel Id allocation to channel control */
> > +	pti_control_frame_built_and_sent(mc);
> > +	return mc;
> > +}
> > +
> > +/*
> > +	The following three functions:
> > +	pti_request_mastercahannel(), mipi_release_masterchannel()
> > +	and pti_writedata() are an API for other kernel drivers to
> > +	access PTI.
> > +*/
> 
> multi-line comment style.
> 
> > +
> > +/**
> > + * pti_request_masterchannel() - Kernel API function used to allocate
> > + *                                a master, channel ID address to write to
> > + *                                PTI HW.
> > + * @type: 0- request Application  master, channel aperture ID write address.
> > + *        1- request OS master, channel aperture ID write address.
> > + *        2- request Modem master, channel aperture ID write
> > + *           address.
> > + *        Other values, error.
> > + * @return: pti_masterchannel struct or 0 for error.
> 
> No '@' on "return".

Same reason here.

> 
> > + *
> > + */
> > +struct pti_masterchannel *pti_request_masterchannel(u8 type)
> > +{
> > +	struct pti_masterchannel *mc;
> > +
> > +	mutex_lock(&alloclock);
> > +
> > +	switch (type) {
> > +
> > +	case 0:
> > +		mc = getID(drv_data->ia_app, MAX_APP_IDS, APP_BASE_ID);
> > +		break;
> > +
> > +	case 1:
> > +		mc = getID(drv_data->ia_os, MAX_OS_IDS, OS_BASE_ID);
> > +		break;
> > +
> > +	case 2:
> > +		mc = getID(drv_data->ia_modem, MAX_MODEM_IDS, MODEM_BASE_ID);
> > +		break;
> > +	default:
> > +		mc = NULL;
> > +	}
> > +
> > +	mutex_unlock(&alloclock);
> > +	return mc;
> > +}
> > +EXPORT_SYMBOL_GPL(pti_request_masterchannel);
> > +
> > +/**
> > + * pti_release_masterchannel() - Kernel API function used to release
> > + *                                a master, channel ID address
> > + *                                used to write to PTI HW.
> > + * @mc: master, channel apeture ID address to be released.
> > + *
> > + */
> > +void pti_release_masterchannel(struct pti_masterchannel *mc)
> > +{
> > +	u8 master, channel, i;
> > +
> > +	mutex_lock(&alloclock);
> > +
> > +	if (mc) {
> > +		master = mc->master;
> > +		channel = mc->channel;
> > +
> > +		if (master == APP_BASE_ID) {
> > +			i = channel >> 3;
> > +			drv_data->ia_app[i] &=  ~(0x80>>(channel & 0x7));
> > +		} else if (master == OS_BASE_ID) {
> > +			i = channel >> 3;
> > +			drv_data->ia_os[i] &= ~(0x80>>(channel & 0x7));
> > +		} else {
> > +			i = channel >> 3;
> > +			drv_data->ia_modem[i] &= ~(0x80>>(channel & 0x7));
> > +		}
> > +
> > +		kfree(mc);
> > +	}
> > +
> > +	mutex_unlock(&alloclock);
> > +}
> > +EXPORT_SYMBOL_GPL(pti_release_masterchannel);
> > +
> > +/**
> > + * pti_writedata() - Kernel API function used to write trace
> > + *                   debugging data to PTI HW.
> > + *
> > + * @mc:    Master, channel aperture ID address to write to.
> > + *         Null value will return with no write occurring.
> > + * @buf:   Trace debuging data to write to the PTI HW.
> > + *         Null value will return with no write occurring.
> > + * @count: Size of buf. Value of 0 or a negative number will
> > + *         retrn with no write occuring.
> 
> 	      return with no write occurring.
> 
> or maybe the @count/@len parameters should be size_t so that they cannot
> be negative.

I'll think about this one, because I thought the check was appropriate
and I'd rather force the user to understand how to use this call
correctly rather than automatically correct for something they may or
may not have intended.

> 
> > + */
> > +void pti_writedata(struct pti_masterchannel *mc, u8 *buf, int count)
> > +{
> > +	/*
> > +	   since this function is exported, this is treated like an
> > +	   API function, thus, all parameters should
> > +	   be checked for validity.
> > +	*/
> 
> comment style.
> 
> > +	if ((mc != NULL) && (buf != NULL) && (count > 0))
> > +		pti_write_to_aperture(mc, buf, count);
> > +	return;
> > +}
> > +EXPORT_SYMBOL_GPL(pti_writedata);
> > +
> > +static void __devexit pti_pci_remove(struct pci_dev *pdev)
> > +{
> > +	struct pti_dev *drv_data;
> > +
> > +	drv_data = pci_get_drvdata(pdev);
> > +	if (drv_data != NULL) {
> > +		pci_iounmap(pdev, drv_data->pti_ioaddr);
> > +		pci_set_drvdata(pdev, NULL);
> > +		kfree(drv_data);
> > +		pci_release_region(pdev, 1);
> > +		pci_disable_device(pdev);
> > +	}
> > +}
> > +
> > +/*
> > +   for the tty_driver_*() basic function descriptions, see tty_driver.h.
> > +   Specific header comments made for PTI-related specifics.
> > +*/
> 
> comment style.
> 
> > +
> > +/**
> > + * pti_tty_driver_open()- Open an Application master, channel aperture
> > + * ID to the PTI device via tty device.
> > + *
> > + * @param tty: tty interface.
> > + * @param filp: filp interface pased to tty_port_open() call.
> 
> drop "param".  Just use:
> 
>  * @tty: <text>
>  * @filp: <text>

Okay.

> 
> > + *
> > + * @return int : Success = 0, otherwise fail.
> 
> No '@' on "return".

Same explanation as above.

> 
> 
> > + *
> > + * The main purpose of using the tty device interface is for
> > + * each tty port to have a unique PTI write aperture.  In an
> > + * example use case, ttyPTI0 gets syslogd and an APP aperture
> > + * ID and ttyPTI1 is where the n_tracesink ldisc hooks to route
> > + * modem messages into PTI.  Modem trace data does not have to
> > + * go to ttyPTI1, but ttyPTI0 and ttyPTI1 do need to be distinct
> > + * master IDs.  These messages go through the PTI HW and out of
> > + * the handheld platform and to the Fido/Lauterbach device.
> > + */
> > +static int pti_tty_driver_open(struct tty_struct *tty, struct file *filp)
> > +{
> > +	int ret = 0;
> > +
> > +	/*
> > +	   we actually want to allocate a new channel per open, per
> > +	   system arch.  HW gives more than plenty channels for a single
> > +	   system task to have its own channel to write trace data. This
> > +	   also removes a locking requirement for the actual write
> > +	   procedure.
> > +	*/
> 
> comment style.
> 
> > +	ret = tty_port_open(&drv_data->port, tty, filp);
> > +
> > +	return ret;
> > +}
> > +
> > +/**
> > + * pti_tty_driver_close()- close tty device and release Application
> > + * master, channel aperture ID to the PTI device via tty device.
> > + *
> > + * @param tty: tty interface.
> > + * @param filp: filp interface pased to tty_port_close() call.
> 
> Incorrect kernel-doc notation.  See Documentation/kernel-doc-nano-HOWTO.txt.
> 
> > + *
> > + * The main purpose of using the tty device interface is to route
> > + * syslog daemon messages to the PTI HW and out of the handheld platform
> > + * and to the Fido/Lauterbach device.
> > + */
> > +static void pti_tty_driver_close(struct tty_struct *tty, struct file *filp)
> > +{
> > +	tty_port_close(&drv_data->port, tty, filp);
> > +
> > +	return;
> > +}
> > +
> > +static int pti_tty_install(struct tty_driver *driver, struct tty_struct *tty)
> > +{
> > +	int idx = tty->index;
> > +	struct pti_tty *pti_tty_data;
> > +	struct pti_masterchannel *mc;
> > +	int ret = tty_init_termios(tty);
> > +
> > +	if (ret == 0) {
> > +		tty_driver_kref_get(driver);
> > +		tty->count++;
> > +		driver->ttys[idx] = tty;
> > +
> > +		pti_tty_data = kmalloc(sizeof(struct pti_tty), GFP_KERNEL);
> > +		if (pti_tty_data == NULL)
> > +			return -ENOMEM;
> > +
> > +		tty->driver_data = pti_tty_data;
> > +
> > +		if (idx == PTITTY_MINOR_START)
> > +			mc = pti_request_masterchannel(0);
> > +		else
> > +			mc = pti_request_masterchannel(2);
> > +
> > +		if (mc == NULL)
> > +			return -ENXIO;
> > +
> > +		pti_tty_data->mc = mc;
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +static void pti_tty_cleanup(struct tty_struct *tty)
> > +{
> > +	struct pti_tty *pti_tty_data;
> > +	struct pti_masterchannel *mc;
> > +
> > +	pti_tty_data = tty->driver_data;
> > +
> > +	if (pti_tty_data != NULL) {
> > +		mc = pti_tty_data->mc;
> > +		pti_release_masterchannel(mc);
> > +		pti_tty_data->mc = NULL;
> > +	}
> > +
> > +	if (pti_tty_data != NULL)
> > +		kfree(pti_tty_data);
> > +
> > +	tty->driver_data = NULL;
> > +}
> > +
> > +/**
> > + * pti_tty_driver_write():  Write trace debugging data through the char
> 
>  * pti_tty_driver_write() - <text>
> 
> > + * interface to the PTI HW.  Part of the misc device implementation.
> > + *
> > + * @param filp: Contains private data which is used to obtain
> > + *              master, channel write ID.
> > + * @param data: trace data to be written.
> > + * @param len:  # of byte to write.
> > + * @return int : # of bytes written, or error.
> 
> Fix kernel-doc notation.  again.  :(
> 
> > + */
> > +static int pti_tty_driver_write(struct tty_struct *tty,
> > +	const unsigned char *buf, int len)
> > +{
> > +	struct pti_masterchannel *mc;
> > +	struct pti_tty *pti_tty_data;
> > +
> > +	pti_tty_data = tty->driver_data;
> > +	mc = pti_tty_data->mc;
> > +	pti_write_to_aperture(mc, (u8 *)buf, len);
> > +
> > +	return len;
> > +}
> > +
> > +static int pti_tty_write_room(struct tty_struct *tty)
> > +{
> > +	return 2048;
> > +}
> > +
> > +/**
> > + * pti_char_open()- Open an Application master, channel aperture
> > + * ID to the PTI device. Part of the misc device implementation.
> > + *
> > + * @param inode: not used.
> > + * @param filp: Output- will have a masterchannel struct set containing
> > + * the allocated application PTI aperture write address.
> > + *
> > + * @return int : Success = 0, otherwise fail.  As of right now,
> > + *         it is not sure what needs to really be initialized
> > + *         for open(), so it always returns 0.
> 
> Fix kernel-doc notation.
> 
> > + */
> > +static int pti_char_open(struct inode *inode, struct file *filp)
> > +{
> > +	struct pti_masterchannel *mc;
> > +
> > +	mc = pti_request_masterchannel(0);
> > +	if (mc == NULL)
> > +		return -ENOMEM;
> > +	filp->private_data = mc;
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pti_char_release()-  Close a char channel to the PTI device. Part
> > + * of the misc device implementation.
> > + *
> > + * @param inode: Not used in this implementaiton.
> > + * @param filp: Contains private_data that contains the master, channel
> > + * ID to be released by the PTI device.
> > + *
> > + * @return int : Success = 0
> 
> fix kernel-doc notation.
> 
> > + */
> > +static int pti_char_release(struct inode *inode, struct file *filp)
> > +{
> > +	pti_release_masterchannel(filp->private_data);
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pti_char_write():  Write trace debugging data through the char
> 
> use '-' instead of ':'
> 
> > + * interface to the PTI HW.  Part of the misc device implementation.
> > + *
> > + * @param filp: Contains private data which is used to obtain
> > + *              master, channel write ID.
> > + * @param data: trace data to be written.
> > + * @param len:  # of byte to write.
> > + * @param ppose: Not used in this function implementation.
> > + * @return int : # of bytes written, or error.
> 
> Fix kernel-doc notation.
> 
> > + *
> > + * Notes: From side discussions with Alan Cox and experimenting
> > + * with PTI debug HW like Nokia's Fido box and Lauterbach
> > + * devices, 8192 byte write buffer used by USER_COPY_SIZE was
> > + * deemed an appropriate size for this type of usage with
> > + * debugging HW.
> > + */
> > +static ssize_t pti_char_write(struct file *filp, const char __user *data,
> > +			      size_t len, loff_t *ppose)
> > +{
> > +	struct pti_masterchannel *mc;
> > +	void *kbuf;
> > +	const char __user *tmp;
> > +	size_t size = USER_COPY_SIZE, n = 0;
> > +
> > +	tmp = data;
> > +	mc = filp->private_data;
> > +
> > +	kbuf = kmalloc(size, GFP_KERNEL);
> > +	if (kbuf == NULL)  {
> > +		pr_err("%s(%d): buf allocation failed\n",
> > +			__func__, __LINE__);
> > +		return 0;
> > +	}
> > +
> > +	do {
> > +		if (len - n > USER_COPY_SIZE)
> > +			size = USER_COPY_SIZE;
> > +		else
> > +			size = len - n;
> > +
> > +		if (copy_from_user(kbuf, tmp, size)) {
> > +			kfree(kbuf);
> > +			return n ? n : -EFAULT;
> > +		}
> > +
> > +		pti_write_to_aperture(mc, kbuf, size);
> > +		n  += size;
> > +		tmp += size;
> > +
> > +	} while (len > n);
> > +
> > +	kfree(kbuf);
> > +	kbuf = NULL;
> > +
> > +	return len;
> > +}
> > +
> > +static const struct tty_operations pti_tty_driver_ops = {
> > +	.open		= pti_tty_driver_open,
> > +	.close		= pti_tty_driver_close,
> > +	.write		= pti_tty_driver_write,
> > +	.write_room	= pti_tty_write_room,
> > +	.install	= pti_tty_install,
> > +	.cleanup	= pti_tty_cleanup
> > +};
> > +
> > +static const struct file_operations pti_char_driver_ops = {
> > +	.owner		= THIS_MODULE,
> > +	.write		= pti_char_write,
> > +	.open		= pti_char_open,
> > +	.release	= pti_char_release,
> > +};
> > +
> > +static struct miscdevice pti_char_driver = {
> > +	.minor		= MISC_DYNAMIC_MINOR,
> > +	.name		= CHARNAME,
> > +	.fops		= &pti_char_driver_ops
> > +};
> > +
> > +static void pti_console_write(struct console *c, const char *buf, unsigned len)
> > +{
> > +	static struct pti_masterchannel mc = {.master  = CONSOLE_ID,
> > +					      .channel = 0};
> > +
> > +	mc.channel = pti_console_channel;
> > +	pti_console_channel = (pti_console_channel + 1) & 0x7f;
> > +
> > +	pti_write_full_frame_to_aperture(&mc, buf, len);
> > +}
> > +
> > +static struct tty_driver *pti_console_device(struct console *c, int *index)
> > +{
> > +	*index = c->index;
> > +	return pti_tty_driver;
> > +}
> > +
> > +static int pti_console_setup(struct console *c, char *opts)
> > +{
> > +	pti_console_channel = 0;
> > +	pti_control_channel = 0;
> > +	return 0;
> > +}
> > +
> > +/* pti_console struct, used to capture OS printk()'s and shift
> > + * out to the PTI device for debugging.  This cannot be
> > + * enabled upon boot because of the possibility of eating
> > + * any serial console printk's (race condition discovered).
> > + * The console should be enabled upon when the tty port is
> > + * used for the first time.  Since the primary purpose for
> > + * the tty port is to hook up syslog to it, the tty port
> > + * will be open for a really long time.
> > + */
> 
> fix long comment style.
> 
> > +static struct console pti_console = {
> > +	.name		= TTYNAME,
> > +	.write		= pti_console_write,
> > +	.device		= pti_console_device,
> > +	.setup		= pti_console_setup,
> > +	.flags		= CON_PRINTBUFFER,
> > +	.index		= 0,
> > +};
> > +
> > +/**
> > + * pti_port_activate(): Used to start/initialize any items upon
> 
> use '-' instead of ':'
> 
> > + * first opening of tty_port().
> > + *
> > + * @param port- The tty port number of the PTI device.
> > + * @param tty-  The tty struct associated with this device.
> > + *
> > + * @return int - Always returns 0.
> 
> fix kernel-doc notation.
> 
> > + *
> > + * Notes: The primary purpose of the PTI tty port 0 is to hook
> > + * the syslog daemon to it; thus this port will be open for a
> > + * very long time.
> > + */
> > +static int pti_port_activate(struct tty_port *port, struct tty_struct *tty)
> > +{
> > +	if (port->tty->index == PTITTY_MINOR_START)
> > +		console_start(&pti_console);
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pti_port_shutdown(): Used to stop/shutdown any items upon the
> 
> use - instead of :
> 
> > + * last tty port close.
> > + *
> > + * @param port- The tty port number of the PTI device.
> 
> fix kernel-doc notation.
> 
> > + *
> > + * Notes: The primary purpose of the PTI tty port 0 is to hook
> > + * the syslog daemon to it; thus this port will be open for a
> > + * very long time.
> > + */
> > +static void pti_port_shutdown(struct tty_port *port)
> > +{
> > +	if (port->tty->index == PTITTY_MINOR_START)
> > +		console_stop(&pti_console);
> > +}
> > +
> > +static const struct tty_port_operations tty_port_ops = {
> > +	.activate = pti_port_activate,
> > +	.shutdown = pti_port_shutdown,
> > +};
> > +
> > +/*
> > +   Note the _probe() call sets everything up and ties the char and tty
> > +   to successfully detecting the PTI device on the pci bus.
> > +*/
> 
> fix long comment style.
> 
> > +
> > +static int __devinit pti_pci_probe(struct pci_dev *pdev,
> > +		const struct pci_device_id *ent)
> > +{
> > +	int retval = -EINVAL;
> > +	int pci_bar = 1;
> > +
> > +	dev_dbg(&pdev->dev, "%s %s(%d): PTI PCI ID %04x:%04x\n", __FILE__,
> > +			__func__, __LINE__, pdev->vendor, pdev->device);
> > +
> > +	retval = misc_register(&pti_char_driver);
> > +	if (retval) {
> > +		pr_err("%s(%d): CHAR registration failed of pti driver\n",
> > +			__func__, __LINE__);
> > +		pr_err("%s(%d): Error value returned: %d\n",
> > +			__func__, __LINE__, retval);
> > +		return retval;
> > +	}
> > +
> > +	retval = pci_enable_device(pdev);
> > +	if (retval != 0) {
> > +		dev_err(&pdev->dev,
> > +			"%s: pci_enable_device() returned error %d\n",
> > +			__func__, retval);
> > +		return retval;
> > +	}
> > +
> > +	drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
> > +
> > +	if (drv_data == NULL) {
> > +		retval = -ENOMEM;
> > +		dev_err(&pdev->dev,
> > +			"%s(%d): kmalloc() returned NULL memory.\n",
> > +			__func__, __LINE__);
> > +		return retval;
> > +	}
> > +	drv_data->pti_addr = pci_resource_start(pdev, pci_bar);
> > +
> > +	retval = pci_request_region(pdev, pci_bar, dev_name(&pdev->dev));
> > +	if (retval != 0) {
> > +		dev_err(&pdev->dev,
> > +			"%s(%d): pci_request_region() returned error %d\n",
> > +			__func__, __LINE__, retval);
> > +		kfree(drv_data);
> > +		return retval;
> > +	}
> > +	drv_data->aperture_base = drv_data->pti_addr+APERTURE_14;
> > +	drv_data->pti_ioaddr =
> > +		ioremap_nocache((u32)drv_data->aperture_base,
> > +		APERTURE_LEN);
> > +	if (!drv_data->pti_ioaddr) {
> > +		pci_release_region(pdev, pci_bar);
> > +		retval = -ENOMEM;
> > +		kfree(drv_data);
> > +		return retval;
> > +	}
> > +
> > +	pci_set_drvdata(pdev, drv_data);
> > +
> > +	tty_port_init(&drv_data->port);
> > +	drv_data->port.ops = &tty_port_ops;
> > +
> > +	tty_register_device(pti_tty_driver, 0, &pdev->dev);
> > +	tty_register_device(pti_tty_driver, 1, &pdev->dev);
> > +
> > +	register_console(&pti_console);
> > +
> > +	return retval;
> > +}
> > +
> > +static struct pci_driver pti_pci_driver = {
> > +	.name		= PCINAME,
> > +	.id_table	= pci_ids,
> > +	.probe		= pti_pci_probe,
> > +	.remove		= pti_pci_remove,
> > +};
> > +
> > +/**
> > + *
> > + * pti_init():
> 
> Needs short function summary on line above.
> 
> > + *
> > + * @return int __init: 0 for success, any other value error.
> 
> fix kernel-doc notation.
> 
> > + *
> > + */
> > +static int __init pti_init(void)
> > +{
> > +	int retval = -EINVAL;
> > +
> > +	/* First register module as tty device */
> > +
> > +	pti_tty_driver = alloc_tty_driver(1);
> > +	if (pti_tty_driver == NULL) {
> > +		pr_err("%s(%d): Memory allocation failed for ptiTTY driver\n",
> > +			__func__, __LINE__);
> > +		return -ENOMEM;
> > +	}
> > +
> > +	pti_tty_driver->owner			= THIS_MODULE;
> > +	pti_tty_driver->magic			= TTY_DRIVER_MAGIC;
> > +	pti_tty_driver->driver_name		= DRIVERNAME;
> > +	pti_tty_driver->name			= TTYNAME;
> > +	pti_tty_driver->major			= 0;
> > +	pti_tty_driver->minor_start		= PTITTY_MINOR_START;
> > +	pti_tty_driver->minor_num		= PTITTY_MINOR_NUM;
> > +	pti_tty_driver->num			= PTITTY_MINOR_NUM;
> > +	pti_tty_driver->type			= TTY_DRIVER_TYPE_SYSTEM;
> > +	pti_tty_driver->subtype			= SYSTEM_TYPE_SYSCONS;
> > +	pti_tty_driver->flags			= TTY_DRIVER_REAL_RAW |
> > +						  TTY_DRIVER_DYNAMIC_DEV;
> > +	pti_tty_driver->init_termios		= tty_std_termios;
> > +
> > +	tty_set_operations(pti_tty_driver, &pti_tty_driver_ops);
> > +
> > +	retval = tty_register_driver(pti_tty_driver);
> > +	if (retval) {
> > +		pr_err("%s(%d): TTY registration failed of pti driver\n",
> > +			__func__, __LINE__);
> > +		pr_err("%s(%d): Error value returned: %d\n",
> > +			__func__, __LINE__, retval);
> > +
> > +		pti_tty_driver = NULL;
> > +		return retval;
> > +	}
> > +
> > +	retval = pci_register_driver(&pti_pci_driver);
> > +
> > +	if (retval) {
> > +		pr_err("%s(%d): PCI registration failed of pti driver\n",
> > +			__func__, __LINE__);
> > +		pr_err("%s(%d): Error value returned: %d\n",
> > +			__func__, __LINE__, retval);
> > +
> > +		tty_unregister_driver(pti_tty_driver);
> > +		pr_err("%s(%d): Unregistering TTY part of pti driver\n",
> > +			__func__, __LINE__);
> > +		pti_tty_driver = NULL;
> > +		return retval;
> > +	}
> > +
> > +	return retval;
> > +}
> > +
> > +/**
> > + * pti_exit(): Unregisters this module as a tty and pci driver.
> 
> use - instead of :
> 
> > + */
> > +static void __exit pti_exit(void)
> > +{
> > +	int retval;
> > +
> > +	tty_unregister_device(pti_tty_driver, 0);
> > +	tty_unregister_device(pti_tty_driver, 1);
> > +
> > +	retval = tty_unregister_driver(pti_tty_driver);
> > +	if (retval) {
> > +		pr_err("%s(%d): TTY unregistration failed of pti driver\n",
> > +			__func__, __LINE__);
> > +		pr_err("%s(%d): Error value returned: %d\n",
> > +			__func__, __LINE__, retval);
> > +	}
> > +
> > +	pci_unregister_driver(&pti_pci_driver);
> > +
> > +	retval = misc_deregister(&pti_char_driver);
> > +	if (retval) {
> > +		pr_err("%s(%d): CHAR unregistration failed of pti driver\n",
> > +			__func__, __LINE__);
> > +		pr_err("%s(%d): Error value returned: %d\n",
> > +			__func__, __LINE__, retval);
> > +	}
> > +
> > +	unregister_console(&pti_console);
> > +	return;
> > +}
> > +
> > +module_init(pti_init);
> > +module_exit(pti_exit);
> > +
> > +MODULE_LICENSE("GPL");
> > +MODULE_AUTHOR("Ken Mills, Jay Freyensee");
> > +MODULE_DESCRIPTION("PTI Driver");
> 
> 
> ---
> ~Randy
> *** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[Randy Dunlap]

On Wed, 20 Apr 2011 16:05:00 -0700 J Freyensee wrote:

> On Tue, 2011-04-19 at 16:15 -0700, Randy Dunlap wrote:
> 
> A couple more comments below.
> 
> > On Tue, 19 Apr 2011 15:58:08 -0700 james_p_freyensee@linux.intel.com wrote:


> > > + * @max_IDS: The max amount of available write IDs to use.
> > > + * @baseID:  The starting SW channel ID, based on the Intel
> > > + *           PTI arch.
> > > + *
> > > + * @return: pti_masterchannel struct containing master, channel ID address,
> > 
> > No '@' on "return".
> 
> Why no '@' on 'return' when just by doing a 'grep -Ri "@return" drivers/
> | wc -l' I count 369 examples of '@return' being used already in the
> kernel?  It looks like an acceptable format to me.

It's not.  See Documentation/kernel-doc-nano-HOWTO.txt.
'@' goes on function parameters (or struct members).
Not on return values.  Those other places should be fixed, but
it's just not a high priority thing to do.


> > > + * or 0 for error.
> > > + *
> > > + * Each bit in the arrays ia_app and ia_os correspond to a master and
> > > + * channel id. The bit is one if the id is taken and 0 if free. For
> > > + * every master there are 128 channel id's.
> > > + */
> > > +static struct pti_masterchannel *getID(u8 *IDarray, int max_IDS, int baseID)
> > > +{


> > > +/**
> > > + * pti_request_masterchannel() - Kernel API function used to allocate
> > > + *                                a master, channel ID address to write to
> > > + *                                PTI HW.
> > > + * @type: 0- request Application  master, channel aperture ID write address.
> > > + *        1- request OS master, channel aperture ID write address.
> > > + *        2- request Modem master, channel aperture ID write
> > > + *           address.
> > > + *        Other values, error.
> > > + * @return: pti_masterchannel struct or 0 for error.
> > 
> > No '@' on "return".
> 
> Same reason here.

Same answer here.



> > > + *
> > > + * @return int : Success = 0, otherwise fail.
> > 
> > No '@' on "return".
> 
> Same explanation as above.

Same reply also.



---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[J Freyensee]

On Wed, 2011-04-20 at 16:10 -0700, Randy Dunlap wrote:
> On Wed, 20 Apr 2011 16:05:00 -0700 J Freyensee wrote:
> 
> > On Tue, 2011-04-19 at 16:15 -0700, Randy Dunlap wrote:
> > 
> > A couple more comments below.
> > 
> > > On Tue, 19 Apr 2011 15:58:08 -0700 james_p_freyensee@linux.intel.com wrote:
> 
> 
> > > > + * @max_IDS: The max amount of available write IDs to use.
> > > > + * @baseID:  The starting SW channel ID, based on the Intel
> > > > + *           PTI arch.
> > > > + *
> > > > + * @return: pti_masterchannel struct containing master, channel ID address,
> > > 
> > > No '@' on "return".
> > 
> > Why no '@' on 'return' when just by doing a 'grep -Ri "@return" drivers/
> > | wc -l' I count 369 examples of '@return' being used already in the
> > kernel?  It looks like an acceptable format to me.
> 
> It's not.  See Documentation/kernel-doc-nano-HOWTO.txt.
> '@' goes on function parameters (or struct members).
> Not on return values.  Those other places should be fixed, but
> it's just not a high priority thing to do.
> 

How should I document return values of functions?  I would like them
documented somehow.

kernel-doc-nano-HOWTO.txt does not say other than give examples of what
I don't want to do and to 'Take a look around the source tree for
examples'.  

So one example I found that documents return values does not seem to
follow kernel-doc-nano-HOWTO.txt:

(acpi/acpica/dsutils.c)
 /*******************************************************************************
 *
 * FUNCTION:    acpi_ds_clear_implicit_return
 *
 * PARAMETERS:  walk_state          - Current State
 *
 * RETURN:      None.
 *

then another driver, net/wireless/libertas/tx.c, does exactly what I do
that I'm being advised against (minus the 's' at the end of 'return'):

/**
 *  @brief This function sends to the host the last transmitted packet,
 *  filling the radiotap headers with transmission information.
 *
 *  @param priv     A pointer to struct lbs_private structure
 *  @param status   A 32 bit value containing transmission status.
 *
 *  @returns void
 */



> 
> > > > + * or 0 for error.
> > > > + *
> > > > + * Each bit in the arrays ia_app and ia_os correspond to a master and
> > > > + * channel id. The bit is one if the id is taken and 0 if free. For
> > > > + * every master there are 128 channel id's.
> > > > + */
> > > > +static struct pti_masterchannel *getID(u8 *IDarray, int max_IDS, int baseID)
> > > > +{
> 
> 
> > > > +/**
> > > > + * pti_request_masterchannel() - Kernel API function used to allocate
> > > > + *                                a master, channel ID address to write to
> > > > + *                                PTI HW.
> > > > + * @type: 0- request Application  master, channel aperture ID write address.
> > > > + *        1- request OS master, channel aperture ID write address.
> > > > + *        2- request Modem master, channel aperture ID write
> > > > + *           address.
> > > > + *        Other values, error.
> > > > + * @return: pti_masterchannel struct or 0 for error.
> > > 
> > > No '@' on "return".
> > 
> > Same reason here.
> 
> Same answer here.
> 
> 
> 
> > > > + *
> > > > + * @return int : Success = 0, otherwise fail.
> > > 
> > > No '@' on "return".
> > 
> > Same explanation as above.
> 
> Same reply also.
> 
> 
> 
> ---
> ~Randy
> *** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[Randy Dunlap]

On Thu, 21 Apr 2011 14:06:39 -0700 J Freyensee wrote:

> On Wed, 2011-04-20 at 16:10 -0700, Randy Dunlap wrote:
> > On Wed, 20 Apr 2011 16:05:00 -0700 J Freyensee wrote:
> > 
> > > On Tue, 2011-04-19 at 16:15 -0700, Randy Dunlap wrote:
> > > 
> > > A couple more comments below.
> > > 
> > > > On Tue, 19 Apr 2011 15:58:08 -0700 james_p_freyensee@linux.intel.com wrote:
> > 
> > 
> > > > > + * @max_IDS: The max amount of available write IDs to use.
> > > > > + * @baseID:  The starting SW channel ID, based on the Intel
> > > > > + *           PTI arch.
> > > > > + *
> > > > > + * @return: pti_masterchannel struct containing master, channel ID address,
> > > > 
> > > > No '@' on "return".
> > > 
> > > Why no '@' on 'return' when just by doing a 'grep -Ri "@return" drivers/
> > > | wc -l' I count 369 examples of '@return' being used already in the
> > > kernel?  It looks like an acceptable format to me.
> > 
> > It's not.  See Documentation/kernel-doc-nano-HOWTO.txt.
> > '@' goes on function parameters (or struct members).
> > Not on return values.  Those other places should be fixed, but
> > it's just not a high priority thing to do.
> > 
> 
> How should I document return values of functions?  I would like them
> documented somehow.

Agreed.

Just use something like:

 * Returns:
 *	0 for success
 *	error code < 0 for errors


> kernel-doc-nano-HOWTO.txt does not say other than give examples of what
> I don't want to do and to 'Take a look around the source tree for
> examples'.  
> 
> So one example I found that documents return values does not seem to
> follow kernel-doc-nano-HOWTO.txt:
> 
> (acpi/acpica/dsutils.c)
>  /*******************************************************************************
>  *
>  * FUNCTION:    acpi_ds_clear_implicit_return
>  *
>  * PARAMETERS:  walk_state          - Current State
>  *
>  * RETURN:      None.
>  *

Yes, I know that there are several that don't do so.
And at least in this case, they have a reason:  acpica is portable code,
not specific to Linux.


> then another driver, net/wireless/libertas/tx.c, does exactly what I do
> that I'm being advised against (minus the 's' at the end of 'return'):
> 
> /**
>  *  @brief This function sends to the host the last transmitted packet,
>  *  filling the radiotap headers with transmission information.
>  *
>  *  @param priv     A pointer to struct lbs_private structure
>  *  @param status   A 32 bit value containing transmission status.
>  *
>  *  @returns void
>  */

I'll be glad to send them email about this.  Thanks for noticing.


> > > > > + * or 0 for error.
> > > > > + *
> > > > > + * Each bit in the arrays ia_app and ia_os correspond to a master and
> > > > > + * channel id. The bit is one if the id is taken and 0 if free. For
> > > > > + * every master there are 128 channel id's.
> > > > > + */
> > > > > +static struct pti_masterchannel *getID(u8 *IDarray, int max_IDS, int baseID)
> > > > > +{
> > 
> > 
> > > > > +/**
> > > > > + * pti_request_masterchannel() - Kernel API function used to allocate
> > > > > + *                                a master, channel ID address to write to
> > > > > + *                                PTI HW.
> > > > > + * @type: 0- request Application  master, channel aperture ID write address.
> > > > > + *        1- request OS master, channel aperture ID write address.
> > > > > + *        2- request Modem master, channel aperture ID write
> > > > > + *           address.
> > > > > + *        Other values, error.
> > > > > + * @return: pti_masterchannel struct or 0 for error.
> > > > 
> > > > No '@' on "return".
> > > 
> > > Same reason here.
> > 
> > Same answer here.
> > 
> > 
> > 
> > > > > + *
> > > > > + * @return int : Success = 0, otherwise fail.
> > > > 
> > > > No '@' on "return".
> > > 
> > > Same explanation as above.
> > 
> > Same reply also.


---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[J Freyensee]

On Tue, 2011-04-19 at 18:25 -0700, David Rientjes wrote:
> On Tue, 19 Apr 2011, james_p_freyensee@linux.intel.com wrote:
> 
> > +static void pti_control_frame_built_and_sent(struct pti_masterchannel *mc)
> > +{
> > +	struct pti_masterchannel mccontrol = {.master = CONTROL_ID,
> > +					      .channel = 0};
> > +	const char *control_format = "%3d %3d %s";
> > +
> > +	char comm[sizeof(current->comm) + 1];
> > +	u8 control_frame[CONTROL_FRAME_LEN];
> > +
> > +	if (!in_interrupt())
> > +		get_task_comm(comm, current);
> > +	else
> > +		strcpy(comm, "Interrupt");
> > +
> > +	/* Ensure our buffer is zero terminated */
> > +	comm[sizeof(current->comm)] = 0;
> > +
> 
> You definitely need to use get_task_comm() here, but that means you can't 
> allocate char comm[] on the stack with anything but TASK_COMM_LEN, which 
> is small enough that it shouldn't be an issue.  Otherwise there's nothing 
> protecting sizeof(current->comm) from changing without holding 
> task_lock(current).

I'm going to look at utilizing get_task_comm() more in this function,
but I think I am okay even if I miss one, as I am just doing a read from
it.  What is written in set_task_comm() states that threads may read
from current->comm without holding the task_lock().  The name could be
incomplete, which would be non-ideal (but acceptable), but it's supposed
to be safe from non-terminating string reads.

And it seems like the fix for

> + comm[sizeof(current->comm)] = 0;

can just be comm[TASK_COMM_LEN].

[PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[james_p_freyensee]

From: J Freyensee <james_p_freyensee@linux.intel.com>

The PTI (Parallel Trace Interface) driver directs
trace data routed from various parts in the system out
through an Intel Penwell PTI port and out of the mobile
device for analysis with a debugging tool (Lauterbach or Fido).
Though n_tracesink and n_tracerouter line discipline drivers
are used to extract modem tracing data to the PTI driver
and other parts of an Intel mobile solution, the PTI driver
can be used independent of n_tracesink and n_tracerouter.

You should select this driver if the target kernel is meant for
an Intel Atom (non-netbook) mobile device containing a MIPI
P1149.7 standard implementation.

Signed-off-by: J Freyensee <james_p_freyensee@linux.intel.com>
---
 drivers/misc/Kconfig  |   13 +
 drivers/misc/Makefile |    1 +
 drivers/misc/pti.c    |  980 +++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/pti.h   |   42 +++
 4 files changed, 1036 insertions(+), 0 deletions(-)
 create mode 100644 drivers/misc/pti.c
 create mode 100644 include/linux/pti.h

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 4e007c6..e87babd 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -144,6 +144,19 @@ config PHANTOM
 	  If you choose to build module, its name will be phantom. If unsure,
 	  say N here.
 
+config INTEL_MID_PTI
+	tristate "Parallel Trace Interface for MIPI P1149.7 cJTAG standard"
+	default n
+	help
+	  The PTI (Parallel Trace Interface) driver directs
+	  trace data routed from various parts in the system out
+	  through an Intel Penwell PTI port and out of the mobile
+	  device for analysis with a debugging tool (Lauterbach or Fido).
+
+	  You should select this driver if the target kernel is meant for
+	  an Intel Atom (non-netbook) mobile device containing a MIPI
+	  P1149.7 standard implementation.
+
 config SGI_IOC4
 	tristate "SGI IOC4 Base IO support"
 	depends on PCI
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index f546860..662aa3c 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_IBM_ASM)		+= ibmasm/
 obj-$(CONFIG_AD525X_DPOT)	+= ad525x_dpot.o
 obj-$(CONFIG_AD525X_DPOT_I2C)	+= ad525x_dpot-i2c.o
 obj-$(CONFIG_AD525X_DPOT_SPI)	+= ad525x_dpot-spi.o
+0bj-$(CONFIG_INTEL_MID_PTI)	+= pti.o
 obj-$(CONFIG_ATMEL_PWM)		+= atmel_pwm.o
 obj-$(CONFIG_ATMEL_SSC)		+= atmel-ssc.o
 obj-$(CONFIG_ATMEL_TCLIB)	+= atmel_tclib.o
diff --git a/drivers/misc/pti.c b/drivers/misc/pti.c
new file mode 100644
index 0000000..bb6f925
--- /dev/null
+++ b/drivers/misc/pti.c
@@ -0,0 +1,980 @@
+/*
+ *  pti.c - PTI driver for cJTAG data extration
+ *
+ *  Copyright (C) Intel 2010
+ *
+ * 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.
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/console.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/pci.h>
+#include <linux/mutex.h>
+#include <linux/miscdevice.h>
+#include <linux/pti.h>
+
+#define DRIVERNAME		"pti"
+#define PCINAME			"pciPTI"
+#define TTYNAME			"ttyPTI"
+#define CHARNAME		"pti"
+#define PTITTY_MINOR_START	0
+#define PTITTY_MINOR_NUM	2
+#define MAX_APP_IDS		16   /* 128 channel ids / u8 bit size */
+#define MAX_OS_IDS		16   /* 128 channel ids / u8 bit size */
+#define MAX_MODEM_IDS		16   /* 128 channel ids / u8 bit size */
+#define MODEM_BASE_ID		71   /* modem master ID address    */
+#define CONTROL_ID		72   /* control master ID address  */
+#define CONSOLE_ID		73   /* console master ID address  */
+#define OS_BASE_ID		74   /* base OS master ID address  */
+#define APP_BASE_ID		80   /* base App master ID address */
+#define CONTROL_FRAME_LEN	32   /* PTI control frame maximum size */
+#define USER_COPY_SIZE		8192 /* 8Kb buffer for user space copy */
+#define APERTURE_14		0x3800000 /* offset to first OS write addr */
+#define APERTURE_LEN		0x400000  /* address length */
+
+struct pti_tty {
+	struct pti_masterchannel *mc;
+};
+
+struct pti_dev {
+	struct tty_port port;
+	unsigned long pti_addr;
+	unsigned long aperture_base;
+	void __iomem *pti_ioaddr;
+	u8 ia_app[MAX_APP_IDS];
+	u8 ia_os[MAX_OS_IDS];
+	u8 ia_modem[MAX_MODEM_IDS];
+};
+
+/*
+ * This protects access to ia_app, ia_os, and ia_modem,
+ * which keeps track of channels allocated in
+ * an aperture write id.
+ */
+static DEFINE_MUTEX(alloclock);
+
+static struct pci_device_id pci_ids[] __devinitconst = {
+		{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x82B)},
+		{0}
+};
+
+static struct tty_driver *pti_tty_driver;
+static struct pti_dev *drv_data;
+
+static unsigned int pti_console_channel;
+static unsigned int pti_control_channel;
+
+/**
+ *  pti_write_to_aperture()- The private write function to PTI HW.
+ *
+ *  @mc: The 'aperture'. It's part of a write address that holds
+ *       a master and channel ID.
+ *  @buf: Data being written to the HW that will ultimately be seen
+ *        in a debugging tool (Fido, Lauterbach).
+ *  @len: Size of buffer.
+ *
+ *  Since each aperture is specified by a unique
+ *  master/channel ID, no two processes will be writing
+ *  to the same aperture at the same time so no lock is required. The
+ *  PTI-Output agent will send these out in the order that they arrived, and
+ *  thus, it will intermix these messages. The debug tool can then later
+ *  regroup the appropriate message segments together reconstituting each
+ *  message.
+ */
+static void pti_write_to_aperture(struct pti_masterchannel *mc,
+				  u8 *buf,
+				  int len)
+{
+	int dwordcnt;
+	int final;
+	int i;
+	u32 ptiword;
+	u32 __iomem *aperture;
+	u8 *p = buf;
+
+	/*
+	 * calculate the aperture offset from the base using the master and
+	 * channel id's.
+	 */
+	aperture = drv_data->pti_ioaddr + (mc->master << 15)
+		+ (mc->channel << 8);
+
+	dwordcnt = len >> 2;
+	final = len - (dwordcnt << 2);	    /* final = trailing bytes    */
+	if (final == 0 && dwordcnt != 0) {  /* always need a final dword */
+		final += 4;
+		dwordcnt--;
+	}
+
+	for (i = 0; i < dwordcnt; i++) {
+		ptiword = be32_to_cpu(*(u32 *)p);
+		p += 4;
+		iowrite32(ptiword, aperture);
+	}
+
+	aperture += PTI_LASTDWORD_DTS;	/* adding DTS signals that is EOM */
+
+	ptiword = 0;
+	for (i = 0; i < final; i++)
+		ptiword |= *p++ << (24-(8*i));
+
+	iowrite32(ptiword, aperture);
+	return;
+}
+
+/**
+ *  pti_control_frame_built_and_sent()- control frame build and send function.
+ *
+ *  @mc: The master / channel structure on which the function
+ *       built a control frame.
+ *
+ *  To be able to post process the PTI contents on host side, a control frame
+ *  is added before sending any PTI content. So the host side knows on
+ *  each PTI frame the name of the thread using a dedicated master / channel.
+ *  The thread name is retrieved from the 'current' global variable.
+ *  This function builds this frame and sends it to a master ID CONTROL_ID.
+ *  The overhead is only 32 bytes since the driver only writes to HW
+ *  in 32 byte chunks.
+ */
+
+static void pti_control_frame_built_and_sent(struct pti_masterchannel *mc)
+{
+	struct pti_masterchannel mccontrol = {.master = CONTROL_ID,
+					      .channel = 0};
+	const char *control_format = "%3d %3d %s";
+	u8 control_frame[CONTROL_FRAME_LEN];
+
+	/*
+	 * Since we access the comm member in current's task_struct,
+	 * we only need to be as large as what 'comm' in that
+	 * structure is.
+	 */
+	char comm[TASK_COMM_LEN];
+
+	if (!in_interrupt())
+		get_task_comm(comm, current);
+	else
+		strncpy(comm, "Interrupt", TASK_COMM_LEN);
+
+	/* Absolutely ensure our buffer is zero terminated. */
+	comm[TASK_COMM_LEN-1] = 0;
+
+	mccontrol.channel = pti_control_channel;
+	pti_control_channel = (pti_control_channel + 1) & 0x7f;
+
+	snprintf(control_frame, CONTROL_FRAME_LEN, control_format, mc->master,
+		mc->channel, comm);
+	pti_write_to_aperture(&mccontrol, control_frame, strlen(control_frame));
+}
+
+/**
+ *  pti_write_full_frame_to_aperture()- high level function to
+ *					write to PTI.
+ *
+ *  @mc:  The 'aperture'. It's part of a write address that holds
+ *        a master and channel ID.
+ *  @buf: Data being written to the HW that will ultimately be seen
+ *        in a debugging tool (Fido, Lauterbach).
+ *  @len: Size of buffer.
+ *
+ *  All threads sending data (either console, user space application, ...)
+ *  are calling the high level function to write to PTI meaning that it is
+ *  possible to add a control frame before sending the content.
+ */
+static void pti_write_full_frame_to_aperture(struct pti_masterchannel *mc,
+						const unsigned char *buf,
+						int len)
+{
+	pti_control_frame_built_and_sent(mc);
+	pti_write_to_aperture(mc, (u8 *)buf, len);
+}
+
+/**
+ * get_id()- Allocate a master and channel ID.
+ *
+ * @id_array: an array of bits representing what channel
+ *            id's are allocated for writing.
+ * @max_ids:  The max amount of available write IDs to use.
+ * @base_id:  The starting SW channel ID, based on the Intel
+ *            PTI arch.
+ *
+ * Returns:
+ *	pti_masterchannel struct with master, channel ID address
+ *	0 for error
+ *
+ * Each bit in the arrays ia_app and ia_os correspond to a master and
+ * channel id. The bit is one if the id is taken and 0 if free. For
+ * every master there are 128 channel id's.
+ */
+static struct pti_masterchannel *get_id(u8 *id_array, int max_ids, int base_id)
+{
+	struct pti_masterchannel *mc;
+	int i, j, mask;
+
+	mc = kmalloc(sizeof(struct pti_masterchannel), GFP_KERNEL);
+	if (mc == NULL)
+		return NULL;
+
+	/* look for a byte with a free bit */
+	for (i = 0; i < max_ids; i++)
+		if (id_array[i] != 0xff)
+			break;
+	if (i == max_ids) {
+		kfree(mc);
+		return NULL;
+	}
+	/* find the bit in the 128 possible channel opportunities */
+	mask = 0x80;
+	for (j = 0; j < 8; j++) {
+		if ((id_array[i] & mask) == 0)
+			break;
+		mask >>= 1;
+	}
+
+	/* grab it */
+	id_array[i] |= mask;
+	mc->master  = base_id;
+	mc->channel = ((i & 0xf)<<3) + j;
+	/* write new master Id / channel Id allocation to channel control */
+	pti_control_frame_built_and_sent(mc);
+	return mc;
+}
+
+/*
+ * The following three functions:
+ * pti_request_mastercahannel(), mipi_release_masterchannel()
+ * and pti_writedata() are an API for other kernel drivers to
+ * access PTI.
+ */
+
+/**
+ * pti_request_masterchannel()- Kernel API function used to allocate
+ *				a master, channel ID address
+ *				to write to PTI HW.
+ *
+ * @type: 0- request Application  master, channel aperture ID write address.
+ *        1- request OS master, channel aperture ID write
+ *           address.
+ *        2- request Modem master, channel aperture ID
+ *           write address.
+ *        Other values, error.
+ *
+ * Returns:
+ *	pti_masterchannel struct
+ *	0 for error
+ */
+struct pti_masterchannel *pti_request_masterchannel(u8 type)
+{
+	struct pti_masterchannel *mc;
+
+	mutex_lock(&alloclock);
+
+	switch (type) {
+
+	case 0:
+		mc = get_id(drv_data->ia_app, MAX_APP_IDS, APP_BASE_ID);
+		break;
+
+	case 1:
+		mc = get_id(drv_data->ia_os, MAX_OS_IDS, OS_BASE_ID);
+		break;
+
+	case 2:
+		mc = get_id(drv_data->ia_modem, MAX_MODEM_IDS, MODEM_BASE_ID);
+		break;
+	default:
+		mc = NULL;
+	}
+
+	mutex_unlock(&alloclock);
+	return mc;
+}
+EXPORT_SYMBOL_GPL(pti_request_masterchannel);
+
+/**
+ * pti_release_masterchannel()- Kernel API function used to release
+ *				a master, channel ID address
+ *				used to write to PTI HW.
+ *
+ * @mc: master, channel apeture ID address to be released.
+ */
+void pti_release_masterchannel(struct pti_masterchannel *mc)
+{
+	u8 master, channel, i;
+
+	mutex_lock(&alloclock);
+
+	if (mc) {
+		master = mc->master;
+		channel = mc->channel;
+
+		if (master == APP_BASE_ID) {
+			i = channel >> 3;
+			drv_data->ia_app[i] &=  ~(0x80>>(channel & 0x7));
+		} else if (master == OS_BASE_ID) {
+			i = channel >> 3;
+			drv_data->ia_os[i] &= ~(0x80>>(channel & 0x7));
+		} else {
+			i = channel >> 3;
+			drv_data->ia_modem[i] &= ~(0x80>>(channel & 0x7));
+		}
+
+		kfree(mc);
+	}
+
+	mutex_unlock(&alloclock);
+}
+EXPORT_SYMBOL_GPL(pti_release_masterchannel);
+
+/**
+ * pti_writedata()- Kernel API function used to write trace
+ *                  debugging data to PTI HW.
+ *
+ * @mc:    Master, channel aperture ID address to write to.
+ *         Null value will return with no write occurring.
+ * @buf:   Trace debuging data to write to the PTI HW.
+ *         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.
+ */
+void pti_writedata(struct pti_masterchannel *mc, u8 *buf, int count)
+{
+	/*
+	 * since this function is exported, this is treated like an
+	 * API function, thus, all parameters should
+	 * be checked for validity.
+	 */
+	if ((mc != NULL) && (buf != NULL) && (count > 0))
+		pti_write_to_aperture(mc, buf, count);
+	return;
+}
+EXPORT_SYMBOL_GPL(pti_writedata);
+
+/**
+ * pti_pci_remove()- Driver exit method to remove PTI from
+ *		   PCI bus.
+ * @pdev: variable containing pci info of PTI.
+ */
+static void __devexit pti_pci_remove(struct pci_dev *pdev)
+{
+	struct pti_dev *drv_data;
+
+	drv_data = pci_get_drvdata(pdev);
+	if (drv_data != NULL) {
+		pci_iounmap(pdev, drv_data->pti_ioaddr);
+		pci_set_drvdata(pdev, NULL);
+		kfree(drv_data);
+		pci_release_region(pdev, 1);
+		pci_disable_device(pdev);
+	}
+}
+
+/*
+ * for the tty_driver_*() basic function descriptions, see tty_driver.h.
+ * Specific header comments made for PTI-related specifics.
+ */
+
+/**
+ * pti_tty_driver_open()- Open an Application master, channel aperture
+ * ID to the PTI device via tty device.
+ *
+ * @tty: tty interface.
+ * @filp: filp interface pased to tty_port_open() call.
+ *
+ * Returns:
+ *	int, 0 for success
+ *	otherwise, fail value
+ *
+ * The main purpose of using the tty device interface is for
+ * each tty port to have a unique PTI write aperture.  In an
+ * example use case, ttyPTI0 gets syslogd and an APP aperture
+ * ID and ttyPTI1 is where the n_tracesink ldisc hooks to route
+ * modem messages into PTI.  Modem trace data does not have to
+ * go to ttyPTI1, but ttyPTI0 and ttyPTI1 do need to be distinct
+ * master IDs.  These messages go through the PTI HW and out of
+ * the handheld platform and to the Fido/Lauterbach device.
+ */
+static int pti_tty_driver_open(struct tty_struct *tty, struct file *filp)
+{
+	/*
+	 * we actually want to allocate a new channel per open, per
+	 * system arch.  HW gives more than plenty channels for a single
+	 * system task to have its own channel to write trace data. This
+	 * also removes a locking requirement for the actual write
+	 * procedure.
+	 */
+	return tty_port_open(&drv_data->port, tty, filp);
+}
+
+/**
+ * pti_tty_driver_close()- close tty device and release Application
+ * master, channel aperture ID to the PTI device via tty device.
+ *
+ * @tty: tty interface.
+ * @filp: filp interface pased to tty_port_close() call.
+ *
+ * The main purpose of using the tty device interface is to route
+ * syslog daemon messages to the PTI HW and out of the handheld platform
+ * and to the Fido/Lauterbach device.
+ */
+static void pti_tty_driver_close(struct tty_struct *tty, struct file *filp)
+{
+	tty_port_close(&drv_data->port, tty, filp);
+}
+
+/**
+ * pti_tty_intstall()- Used to set up specific master-channels
+ *		       to tty ports for organizational purposes when
+ *		       tracing viewed from debuging tools.
+ *
+ * @driver: tty driver information.
+ * @tty: tty struct containing pti information.
+ *
+ * Returns:
+ *	0 for success
+ *	otherwise, error
+ */
+static int pti_tty_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	int idx = tty->index;
+	struct pti_tty *pti_tty_data;
+	int ret = tty_init_termios(tty);
+
+	if (ret == 0) {
+		tty_driver_kref_get(driver);
+		tty->count++;
+		driver->ttys[idx] = tty;
+
+		pti_tty_data = kmalloc(sizeof(struct pti_tty), GFP_KERNEL);
+		if (pti_tty_data == NULL)
+			return -ENOMEM;
+
+		if (idx == PTITTY_MINOR_START)
+			pti_tty_data->mc = pti_request_masterchannel(0);
+		else
+			pti_tty_data->mc = pti_request_masterchannel(2);
+
+		if (pti_tty_data->mc == NULL)
+			return -ENXIO;
+		tty->driver_data = pti_tty_data;
+	}
+
+	return ret;
+}
+
+/**
+ * pti_tty_cleanup()- Used to de-allocate master-channel resources
+ *		      tied to tty's of this driver.
+ *
+ * @tty: tty struct containing pti information.
+ */
+static void pti_tty_cleanup(struct tty_struct *tty)
+{
+	struct pti_tty *pti_tty_data = tty->driver_data;
+	if (pti_tty_data == NULL)
+		return;
+	pti_release_masterchannel(pti_tty_data->mc);
+	kfree(tty->driver_data);
+	tty->driver_data = NULL;
+}
+
+/**
+ * pti_tty_driver_write()-  Write trace debugging data through the char
+ * interface to the PTI HW.  Part of the misc device implementation.
+ *
+ * @filp: Contains private data which is used to obtain
+ *        master, channel write ID.
+ * @data: trace data to be written.
+ * @len:  # of byte to write.
+ *
+ * Returns:
+ *	int, # of bytes written
+ *	otherwise, error
+ */
+static int pti_tty_driver_write(struct tty_struct *tty,
+	const unsigned char *buf, int len)
+{
+	struct pti_tty *pti_tty_data = tty->driver_data;
+	if ((pti_tty_data != NULL) && (pti_tty_data->mc != NULL)) {
+		pti_write_to_aperture(pti_tty_data->mc, (u8 *)buf, len);
+		return len;
+	}
+	/*
+	 * we can't write to the pti hardware if the private driver_data
+	 * and the mc address is not there.
+	 */
+	else
+		return -EFAULT;
+}
+
+/**
+ * pti_tty_write_room()- Always returns 2048.
+ *
+ * @tty: contains tty info of the pti driver.
+ */
+static int pti_tty_write_room(struct tty_struct *tty)
+{
+	return 2048;
+}
+
+/**
+ * pti_char_open()- Open an Application master, channel aperture
+ * ID to the PTI device. Part of the misc device implementation.
+ *
+ * @inode: not used.
+ * @filp:  Output- will have a masterchannel struct set containing
+ *                 the allocated application PTI aperture write address.
+ *
+ * Returns:
+ *	int, 0 for success
+ *	otherwise, a fail value
+ */
+static int pti_char_open(struct inode *inode, struct file *filp)
+{
+	struct pti_masterchannel *mc;
+
+	/*
+	 * We really do want to fail immediately if
+	 * pti_request_masterchannel() fails,
+	 * before assigning the value to filp->private_data.
+	 * Slightly easier to debug if this driver needs debugging.
+	 */
+	mc = pti_request_masterchannel(0);
+	if (mc == NULL)
+		return -ENOMEM;
+	filp->private_data = mc;
+	return 0;
+}
+
+/**
+ * pti_char_release()-  Close a char channel to the PTI device. Part
+ * of the misc device implementation.
+ *
+ * @inode: Not used in this implementaiton.
+ * @filp:  Contains private_data that contains the master, channel
+ *         ID to be released by the PTI device.
+ *
+ * Returns:
+ *	always 0
+ */
+static int pti_char_release(struct inode *inode, struct file *filp)
+{
+	pti_release_masterchannel(filp->private_data);
+	kfree(filp->private_data);
+	return 0;
+}
+
+/**
+ * pti_char_write()-  Write trace debugging data through the char
+ * interface to the PTI HW.  Part of the misc device implementation.
+ *
+ * @filp:  Contains private data which is used to obtain
+ *         master, channel write ID.
+ * @data:  trace data to be written.
+ * @len:   # of byte to write.
+ * @ppose: Not used in this function implementation.
+ *
+ * Returns:
+ *	int, # of bytes written
+ *	otherwise, error value
+ *
+ * Notes: From side discussions with Alan Cox and experimenting
+ * with PTI debug HW like Nokia's Fido box and Lauterbach
+ * devices, 8192 byte write buffer used by USER_COPY_SIZE was
+ * deemed an appropriate size for this type of usage with
+ * debugging HW.
+ */
+static ssize_t pti_char_write(struct file *filp, const char __user *data,
+			      size_t len, loff_t *ppose)
+{
+	struct pti_masterchannel *mc;
+	void *kbuf;
+	const char __user *tmp;
+	size_t size = USER_COPY_SIZE;
+	size_t n = 0;
+
+	tmp = data;
+	mc = filp->private_data;
+
+	kbuf = kmalloc(size, GFP_KERNEL);
+	if (kbuf == NULL)  {
+		pr_err("%s(%d): buf allocation failed\n",
+			__func__, __LINE__);
+		return -ENOMEM;
+	}
+
+	do {
+		if (len - n > USER_COPY_SIZE)
+			size = USER_COPY_SIZE;
+		else
+			size = len - n;
+
+		if (copy_from_user(kbuf, tmp, size)) {
+			kfree(kbuf);
+			return n ? n : -EFAULT;
+		}
+
+		pti_write_to_aperture(mc, kbuf, size);
+		n  += size;
+		tmp += size;
+
+	} while (len > n);
+
+	kfree(kbuf);
+	return len;
+}
+
+static const struct tty_operations pti_tty_driver_ops = {
+	.open		= pti_tty_driver_open,
+	.close		= pti_tty_driver_close,
+	.write		= pti_tty_driver_write,
+	.write_room	= pti_tty_write_room,
+	.install	= pti_tty_install,
+	.cleanup	= pti_tty_cleanup
+};
+
+static const struct file_operations pti_char_driver_ops = {
+	.owner		= THIS_MODULE,
+	.write		= pti_char_write,
+	.open		= pti_char_open,
+	.release	= pti_char_release,
+};
+
+static struct miscdevice pti_char_driver = {
+	.minor		= MISC_DYNAMIC_MINOR,
+	.name		= CHARNAME,
+	.fops		= &pti_char_driver_ops
+};
+
+/**
+ * pti_console_write()-  Write to the console that has been acquired.
+ *
+ * @c:   Not used in this implementaiton.
+ * @buf: Data to be written.
+ * @len: Length of buf.
+ */
+static void pti_console_write(struct console *c, const char *buf, unsigned len)
+{
+	static struct pti_masterchannel mc = {.master  = CONSOLE_ID,
+					      .channel = 0};
+
+	mc.channel = pti_console_channel;
+	pti_console_channel = (pti_console_channel + 1) & 0x7f;
+
+	pti_write_full_frame_to_aperture(&mc, buf, len);
+}
+
+/**
+ * pti_console_device()-  Return the driver tty structure and set the
+ *			  associated index implementation.
+ *
+ * @c:     Console device of the driver.
+ * @index: index associated with c.
+ *
+ * Returns:
+ *	always value of pti_tty_driver structure when this function
+ *	is called.
+ */
+static struct tty_driver *pti_console_device(struct console *c, int *index)
+{
+	*index = c->index;
+	return pti_tty_driver;
+}
+
+/**
+ * pti_console_setup()-  Initialize console variables used by the driver.
+ *
+ * @c:     Not used.
+ * @opts:  Not used.
+ *
+ * Returns:
+ *	always 0.
+ */
+static int pti_console_setup(struct console *c, char *opts)
+{
+	pti_console_channel = 0;
+	pti_control_channel = 0;
+	return 0;
+}
+
+/*
+ * pti_console struct, used to capture OS printk()'s and shift
+ * out to the PTI device for debugging.  This cannot be
+ * enabled upon boot because of the possibility of eating
+ * any serial console printk's (race condition discovered).
+ * The console should be enabled upon when the tty port is
+ * used for the first time.  Since the primary purpose for
+ * the tty port is to hook up syslog to it, the tty port
+ * will be open for a really long time.
+ */
+static struct console pti_console = {
+	.name		= TTYNAME,
+	.write		= pti_console_write,
+	.device		= pti_console_device,
+	.setup		= pti_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= 0,
+};
+
+/**
+ * pti_port_activate()- Used to start/initialize any items upon
+ * first opening of tty_port().
+ *
+ * @port- The tty port number of the PTI device.
+ * @tty-  The tty struct associated with this device.
+ *
+ * Returns:
+ *	always returns 0
+ *
+ * Notes: The primary purpose of the PTI tty port 0 is to hook
+ * the syslog daemon to it; thus this port will be open for a
+ * very long time.
+ */
+static int pti_port_activate(struct tty_port *port, struct tty_struct *tty)
+{
+	if (port->tty->index == PTITTY_MINOR_START)
+		console_start(&pti_console);
+	return 0;
+}
+
+/**
+ * pti_port_shutdown()- Used to stop/shutdown any items upon the
+ * last tty port close.
+ *
+ * @port- The tty port number of the PTI device.
+ *
+ * Notes: The primary purpose of the PTI tty port 0 is to hook
+ * the syslog daemon to it; thus this port will be open for a
+ * very long time.
+ */
+static void pti_port_shutdown(struct tty_port *port)
+{
+	if (port->tty->index == PTITTY_MINOR_START)
+		console_stop(&pti_console);
+}
+
+static const struct tty_port_operations tty_port_ops = {
+	.activate = pti_port_activate,
+	.shutdown = pti_port_shutdown,
+};
+
+/*
+ * Note the _probe() call sets everything up and ties the char and tty
+ * to successfully detecting the PTI device on the pci bus.
+ */
+
+/**
+ * pti_pci_probe()- Used to detect pti on the pci bus and set
+ *		    things up in the driver.
+ *
+ * @pdev- pci_dev struct values for pti.
+ * @ent-  pci_device_id struct for pti driver.
+ *
+ * Returns:
+ *	0 for success
+ *	otherwise, error
+ */
+static int __devinit pti_pci_probe(struct pci_dev *pdev,
+		const struct pci_device_id *ent)
+{
+	int retval = -EINVAL;
+	int pci_bar = 1;
+
+	dev_dbg(&pdev->dev, "%s %s(%d): PTI PCI ID %04x:%04x\n", __FILE__,
+			__func__, __LINE__, pdev->vendor, pdev->device);
+
+	retval = misc_register(&pti_char_driver);
+	if (retval) {
+		pr_err("%s(%d): CHAR registration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+		return retval;
+	}
+
+	retval = pci_enable_device(pdev);
+	if (retval != 0) {
+		dev_err(&pdev->dev,
+			"%s: pci_enable_device() returned error %d\n",
+			__func__, retval);
+		return retval;
+	}
+
+	drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
+
+	if (drv_data == NULL) {
+		retval = -ENOMEM;
+		dev_err(&pdev->dev,
+			"%s(%d): kmalloc() returned NULL memory.\n",
+			__func__, __LINE__);
+		return retval;
+	}
+	drv_data->pti_addr = pci_resource_start(pdev, pci_bar);
+
+	retval = pci_request_region(pdev, pci_bar, dev_name(&pdev->dev));
+	if (retval != 0) {
+		dev_err(&pdev->dev,
+			"%s(%d): pci_request_region() returned error %d\n",
+			__func__, __LINE__, retval);
+		kfree(drv_data);
+		return retval;
+	}
+	drv_data->aperture_base = drv_data->pti_addr+APERTURE_14;
+	drv_data->pti_ioaddr =
+		ioremap_nocache((u32)drv_data->aperture_base,
+		APERTURE_LEN);
+	if (!drv_data->pti_ioaddr) {
+		pci_release_region(pdev, pci_bar);
+		retval = -ENOMEM;
+		kfree(drv_data);
+		return retval;
+	}
+
+	pci_set_drvdata(pdev, drv_data);
+
+	tty_port_init(&drv_data->port);
+	drv_data->port.ops = &tty_port_ops;
+
+	tty_register_device(pti_tty_driver, 0, &pdev->dev);
+	tty_register_device(pti_tty_driver, 1, &pdev->dev);
+
+	register_console(&pti_console);
+
+	return retval;
+}
+
+static struct pci_driver pti_pci_driver = {
+	.name		= PCINAME,
+	.id_table	= pci_ids,
+	.probe		= pti_pci_probe,
+	.remove		= pti_pci_remove,
+};
+
+/**
+ *
+ * pti_init()- Overall entry/init call to the pti driver.
+ *             It starts the registration process with the kernel.
+ *
+ * Returns:
+ *	int __init, 0 for success
+ *	otherwise value is an error
+ *
+ */
+static int __init pti_init(void)
+{
+	int retval = -EINVAL;
+
+	/* First register module as tty device */
+
+	pti_tty_driver = alloc_tty_driver(1);
+	if (pti_tty_driver == NULL) {
+		pr_err("%s(%d): Memory allocation failed for ptiTTY driver\n",
+			__func__, __LINE__);
+		return -ENOMEM;
+	}
+
+	pti_tty_driver->owner			= THIS_MODULE;
+	pti_tty_driver->magic			= TTY_DRIVER_MAGIC;
+	pti_tty_driver->driver_name		= DRIVERNAME;
+	pti_tty_driver->name			= TTYNAME;
+	pti_tty_driver->major			= 0;
+	pti_tty_driver->minor_start		= PTITTY_MINOR_START;
+	pti_tty_driver->minor_num		= PTITTY_MINOR_NUM;
+	pti_tty_driver->num			= PTITTY_MINOR_NUM;
+	pti_tty_driver->type			= TTY_DRIVER_TYPE_SYSTEM;
+	pti_tty_driver->subtype			= SYSTEM_TYPE_SYSCONS;
+	pti_tty_driver->flags			= TTY_DRIVER_REAL_RAW |
+						  TTY_DRIVER_DYNAMIC_DEV;
+	pti_tty_driver->init_termios		= tty_std_termios;
+
+	tty_set_operations(pti_tty_driver, &pti_tty_driver_ops);
+
+	retval = tty_register_driver(pti_tty_driver);
+	if (retval) {
+		pr_err("%s(%d): TTY registration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+
+		pti_tty_driver = NULL;
+		return retval;
+	}
+
+	retval = pci_register_driver(&pti_pci_driver);
+
+	if (retval) {
+		pr_err("%s(%d): PCI registration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+
+		tty_unregister_driver(pti_tty_driver);
+		pr_err("%s(%d): Unregistering TTY part of pti driver\n",
+			__func__, __LINE__);
+		pti_tty_driver = NULL;
+		return retval;
+	}
+
+	return retval;
+}
+
+/**
+ * pti_exit()- Unregisters this module as a tty and pci driver.
+ */
+static void __exit pti_exit(void)
+{
+	int retval;
+
+	tty_unregister_device(pti_tty_driver, 0);
+	tty_unregister_device(pti_tty_driver, 1);
+
+	retval = tty_unregister_driver(pti_tty_driver);
+	if (retval) {
+		pr_err("%s(%d): TTY unregistration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+	}
+
+	pci_unregister_driver(&pti_pci_driver);
+
+	retval = misc_deregister(&pti_char_driver);
+	if (retval) {
+		pr_err("%s(%d): CHAR unregistration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+	}
+
+	unregister_console(&pti_console);
+	return;
+}
+
+module_init(pti_init);
+module_exit(pti_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Ken Mills, Jay Freyensee");
+MODULE_DESCRIPTION("PTI Driver");
+
diff --git a/include/linux/pti.h b/include/linux/pti.h
new file mode 100644
index 0000000..81af667
--- /dev/null
+++ b/include/linux/pti.h
@@ -0,0 +1,42 @@
+/*
+ *  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 will allow other parts of the OS to use the
+ * interface to write out it's contents for debugging a mobile system.
+ */
+
+#ifndef PTI_H_
+#define PTI_H_
+
+/* offset for last dword of any PTI message. Part of MIPI P1149.7 */
+#define PTI_LASTDWORD_DTS	0x30
+
+/* basic structure used as a write address to the PTI HW */
+struct pti_masterchannel {
+	u8 master;
+	u8 channel;
+};
+
+/* the following functions are defined in misc/pti.c */
+void pti_writedata(struct pti_masterchannel *mc, u8 *buf, int count);
+struct pti_masterchannel *pti_request_masterchannel(u8 type);
+void pti_release_masterchannel(struct pti_masterchannel *mc);
+
+#endif /*PTI_H_*/
-- 
1.7.2.3

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[J Freyensee]

> > 
> > static void pti_tty_cleanup(struct tty_struct *tty)
> > {
> >      if (!tty->driver_data)
> >              return;
> >      pti_release_masterchannel(tty->driver_data->mc);
> >      kfree(tty->driver_data);
> > }
> > 
> 
> I think I answered this already; I like the suggestion and will tweak.
> 
> > ...
> > > +static int pti_tty_driver_write(struct tty_struct *tty,
> > > +	const unsigned char *buf, int len)
> > > +{
> > > +	struct pti_masterchannel *mc;
> > > +	struct pti_tty *pti_tty_data;
> > > +
> > > +	pti_tty_data = tty->driver_data;
> > > +	mc = pti_tty_data->mc;
> > > +	pti_write_to_aperture(mc, (u8 *)buf, len);
> > > +
> > > +	return len;
> > > +}
> > 
> > I'd like to suggest this as an alternative:
> > 
> > static int pti_tty_driver_write(struct tty_struct *tty,
> >      const unsigned char *buf, int len)
> > {
> >      pti_write_to_aperture(tty->driver_data->mc, (u8 *)buf, len);
> >      return len;
> > }
> > 
> > 
> 
> If there is no objections I will do it.  What I've coded is the observed
> coding style I've seen, if for no other reason that to shorten up the
> number of '->' used in accessing a member of driver_data.  But this
> doesn't look so bad/ugly.
> 

Ok, so now I remember why this suggestion isn't good and I am going to
have to go back to what I had before.  Some picky compilers do not like
for you to do operations on (void *) variables, other than a beginning
assign statement to a variable with an actual type.    

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[Jesper Juhl]

On Thu, 5 May 2011, J Freyensee wrote:

> On Sun, 2011-04-24 at 02:55 +0200, Jesper Juhl wrote:
...
> > 
> >  kbuff is a local variable. What's the point in assigning NULL to it just 
> > before you return? Just get rid of that silly assignment.
> 
> I err on the side of paranoia and default to attempting to use good
> programming practices and rather receiving comments like this, than the
> alternative where I should have assigned something to NULL/0 and I
> introduce a security flaw in the driver/kernel.
> 

That is all well and good, but assigning to a local variable just before 
it goes out of scope is utterly pointless. Nothing can access the variable 
afterwards, so it's value is completely irrelevant at that point.

-- 
Jesper Juhl <jj@chaosbits.net>       http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
Plain text mails only, please.

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[Jesper Juhl]

On Thu, 5 May 2011, J Freyensee wrote:

[...]
> 
> I'm no means an expert in the kernel, but I assume kfree() is like C
> free(), that it's a nop if it receives a NULL value?
> 

Yes. kfree(NULL) is a nop, so you can avoid the conditional branch.

-- 
Jesper Juhl <jj@chaosbits.net>       http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
Plain text mails only, please.

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[J Freyensee]

On Sun, 2011-04-24 at 02:55 +0200, Jesper Juhl wrote:
> On Fri, 22 Apr 2011, james_p_freyensee@linux.intel.com wrote:
> 
> > From: J Freyensee <james_p_freyensee@linux.intel.com>
> > 
> > The PTI (Parallel Trace Interface) driver directs
> > trace data routed from various parts in the system out
> > through an Intel Penwell PTI port and out of the mobile
> > device for analysis with a debugging tool (Lauterbach or Fido).
> > Though n_tracesink and n_tracerouter line discipline drivers
> > are used to extract modem tracing data to the PTI driver
> > and other parts of an Intel mobile solution, the PTI driver
> > can be used independent of n_tracesink and n_tracerouter.
> > 
> > You should select this driver if the target kernel is meant for
> > an Intel Atom (non-netbook) mobile device containing a MIPI
> > P1149.7 standard implementation.
> > 
> > Signed-off-by: J Freyensee <james_p_freyensee@linux.intel.com>
> 
> A few comments below.
> 
> ...
> > +#define DRIVERNAME		"pti"
> > +#define PCINAME			"pciPTI"
> > +#define TTYNAME			"ttyPTI"
> > +#define CHARNAME		"pti"
> > +#define PTITTY_MINOR_START	0
> > +#define PTITTY_MINOR_NUM	2
> > +#define MAX_APP_IDS		16   /* 128 channel ids / u8 bit size */
> > +#define MAX_OS_IDS		16   /* 128 channel ids / u8 bit size */
> > +#define MAX_MODEM_IDS		16   /* 128 channel ids / u8 bit size */
> > +#define MODEM_BASE_ID		71   /* modem master ID address    */
> ...
> 
> Would be nice if the values of these defines would line up nicely.
> 
> 
> ...
> > +static struct pci_device_id pci_ids[] __devinitconst = {
> > +		{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x82B) },
> > +		{0}
> ...
> 
> Why are there spaces after the opening { and before the closing } for the 
> first entry, but not the second. Looks like you need to pick a 
> consistent style.
> 
> 
> > + *  regroup the appropriate message segments together reconstituting each
> > + *  message.
> > + */
> > +static void pti_write_to_aperture(struct pti_masterchannel *mc,
> > +				  u8 *buf,
> > +				  int len)
> > +{
> > +	int dwordcnt, final, i;
> > +	u32 ptiword;
> > +	u8 *p;
> > +	u32 __iomem *aperture;
> > +
> > +	p = buf;
> ...
> 
> Perhaps save a few lines by doing
> 
> static void pti_write_to_aperture(struct pti_masterchannel *mc,
>                                u8 *buf,
>                                int len)
> {
>      int dwordcnt, final, i;
>      u32 ptiword;
>      u32 __iomem *aperture;
>      u8 *p = buf;
> 
> 

I can make the tweak.

> ...
> > +void pti_writedata(struct pti_masterchannel *mc, u8 *buf, int count)
> > +{
> > +	/*
> > +	 * since this function is exported, this is treated like an
> > +	 * API function, thus, all parameters should
> > +	 * be checked for validity.
> > +	 */
> > +	if ((mc != NULL) && (buf != NULL) && (count > 0))
> > +		pti_write_to_aperture(mc, buf, count);
> > +	return;
> ...
> 
> Pointless return; statement.
> 
> 
> ...
> > +static void __devexit pti_pci_remove(struct pci_dev *pdev)
> > +{
> > +	struct pti_dev *drv_data;
> > +
> > +	drv_data = pci_get_drvdata(pdev);
> > +	if (drv_data != NULL) {
> 
> Perhaps
> 
> static void __devexit pti_pci_remove(struct pci_dev *pdev)
> {
>      struct pti_dev *drv_data = pci_get_drvdata(pdev);
>      
>      if (drv_data) {
> 
> 

I'd rather keep my way.  Just easier to read and more self-explanatory.
I realize everyone on this list are expert programmers, but I tend to
default to code that is dead-simple to read and understand.

> ...
> > +static int pti_tty_driver_open(struct tty_struct *tty, struct file *filp)
> > +{
> > +	int ret = 0;
> > +
> > +	/*
> > +	 * we actually want to allocate a new channel per open, per
> > +	 * system arch.  HW gives more than plenty channels for a single
> > +	 * system task to have its own channel to write trace data. This
> > +	 * also removes a locking requirement for the actual write
> > +	 * procedure.
> > +	 */
> > +	ret = tty_port_open(&drv_data->port, tty, filp);
> > +
> > +	return ret;
> > +}
> ...
> 
> Why not get rid of the pointless 'ret' variable and simplify this down to
> 
> static int pti_tty_driver_open(struct tty_struct *tty, struct file *filp)
> {     
>      /*
>       * we actually want to allocate a new channel per open, per
>       * system arch.  HW gives more than plenty channels for a single
>       * system task to have its own channel to write trace data. This
>       * also removes a locking requirement for the actual write
>       * procedure.
>       */
>      return tty_port_open(&drv_data->port, tty, filp);
> }
> 
> ??
> 

Sure, I can change it.

> 
> ...
> > +static void pti_tty_driver_close(struct tty_struct *tty, struct file *filp)
> > +{
> > +	tty_port_close(&drv_data->port, tty, filp);
> > +
> > +	return;
> > +}
> 
> Just kill that superfluous return statement.
> 
> 
Dido here too.

> ...
> > +static void pti_tty_cleanup(struct tty_struct *tty)
> > +{
> > +	struct pti_tty *pti_tty_data;
> > +	struct pti_masterchannel *mc;
> > +
> > +	pti_tty_data = tty->driver_data;
> > +
> > +	if (pti_tty_data != NULL) {
> > +		mc = pti_tty_data->mc;
> > +		pti_release_masterchannel(mc);
> > +		pti_tty_data->mc = NULL;
> > +	}
> > +
> > +	if (pti_tty_data != NULL)
> > +		kfree(pti_tty_data);
> > +
> > +	tty->driver_data = NULL;
> > +}
> 
> How about this instead?
> 
> static void pti_tty_cleanup(struct tty_struct *tty)
> {
>      if (!tty->driver_data)
>              return;
>      pti_release_masterchannel(tty->driver_data->mc);
>      kfree(tty->driver_data);
> }
> 

I think I answered this already; I like the suggestion and will tweak.

> ...
> > +static int pti_tty_driver_write(struct tty_struct *tty,
> > +	const unsigned char *buf, int len)
> > +{
> > +	struct pti_masterchannel *mc;
> > +	struct pti_tty *pti_tty_data;
> > +
> > +	pti_tty_data = tty->driver_data;
> > +	mc = pti_tty_data->mc;
> > +	pti_write_to_aperture(mc, (u8 *)buf, len);
> > +
> > +	return len;
> > +}
> 
> I'd like to suggest this as an alternative:
> 
> static int pti_tty_driver_write(struct tty_struct *tty,
>      const unsigned char *buf, int len)
> {
>      pti_write_to_aperture(tty->driver_data->mc, (u8 *)buf, len);
>      return len;
> }
> 
> 

If there is no objections I will do it.  What I've coded is the observed
coding style I've seen, if for no other reason that to shorten up the
number of '->' used in accessing a member of driver_data.  But this
doesn't look so bad/ugly.

> ..
> > +static int pti_char_open(struct inode *inode, struct file *filp)
> > +{
> > +	struct pti_masterchannel *mc;
> > +
> > +	mc = pti_request_masterchannel(0);
> > +	if (mc == NULL)
> > +		return -ENOMEM;
> > +	filp->private_data = mc;
> > +	return 0;
> > +}
> 
> Ok, so I admit that I haven't looked to check if it's actually important 
> that filp->private_data does not get overwritten if 
> pti_request_masterchannel() returns NULL, but if we assume that it is not 
> important, then this would be an improvement IMHO:
> 
> static int pti_char_open(struct inode *inode, struct file *filp)
> {
>      filp->private_data = pti_request_masterchannel(0);
>      if (!filp->private_data)
>              return -ENOMEM; 
>      return 0;
> }
> 
> 

I'll play with this with a debugging tool, but I may want to leave the
code the way I have it.

> ...
> > +
> > +/**
> > + * pti_char_release()-  Close a char channel to the PTI device. Part
> > + * of the misc device implementation.
> > + *
> > + * @inode: Not used in this implementaiton.
> > + * @filp:  Contains private_data that contains the master, channel
> > + *         ID to be released by the PTI device.
> > + *
> > + * Returns:
> > + *	always 0
> 
> Why not void then?

Because the prototype for struct file_definitions calls for returning an
int value.

> 
> 
> > +	pti_release_masterchannel(filp->private_data);
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pti_char_write()-  Write trace debugging data through the char
> > + * interface to the PTI HW.  Part of the misc device implementation.
> > + *
> > + * @filp:  Contains private data which is used to obtain
> > + *         master, channel write ID.
> > + * @data:  trace data to be written.
> > + * @len:   # of byte to write.
> > + * @ppose: Not used in this function implementation.
> > + *
> > + * Returns:
> > + *	int, # of bytes written
> > + *	otherwise, error value
> > + *
> > + * Notes: From side discussions with Alan Cox and experimenting
> > + * with PTI debug HW like Nokia's Fido box and Lauterbach
> > + * devices, 8192 byte write buffer used by USER_COPY_SIZE was
> > + * deemed an appropriate size for this type of usage with
> > + * debugging HW.
> > + */
> > +static ssize_t pti_char_write(struct file *filp, const char __user *data,
> > +			      size_t len, loff_t *ppose)
> > +{
> > +	struct pti_masterchannel *mc;
> > +	void *kbuf;
> > +	const char __user *tmp;
> > +	size_t size = USER_COPY_SIZE, n = 0;
> 
> It would be nice to declare these two variables on two sepperate lines 
> IMO.

K, I can fix.

> 
> > +
> > +	tmp = data;
> > +	mc = filp->private_data;
> > +
> > +	kbuf = kmalloc(size, GFP_KERNEL);
> > +	if (kbuf == NULL)  {
> > +		pr_err("%s(%d): buf allocation failed\n",
> > +			__func__, __LINE__);
> > +		return 0;
> 
> Shouldn't you be returning -ENOMEM here?
> 
> > +	}
> > +
> > +	do {
> > +		if (len - n > USER_COPY_SIZE)
> > +			size = USER_COPY_SIZE;
> > +		else
> > +			size = len - n;
> > +
> > +		if (copy_from_user(kbuf, tmp, size)) {
> > +			kfree(kbuf);
> > +			return n ? n : -EFAULT;
> > +		}
> > +
> > +		pti_write_to_aperture(mc, kbuf, size);
> > +		n  += size;
> > +		tmp += size;
> > +
> > +	} while (len > n);
> > +
> > +	kfree(kbuf);
> > +	kbuf = NULL;
> > +
> 
>  kbuff is a local variable. What's the point in assigning NULL to it just 
> before you return? Just get rid of that silly assignment.

I err on the side of paranoia and default to attempting to use good
programming practices and rather receiving comments like this, than the
alternative where I should have assigned something to NULL/0 and I
introduce a security flaw in the driver/kernel.

> 
> 
> ...
> > + * pti_char_release()-  Close a char channel to the PTI device. Part
> > + * of the misc device implementation.
> > + *
> > + * @inode: Not used in this implementaiton.
> > + * @filp:  Contains private_data that contains the master, channel
> > + *         ID to be released by the PTI device.
> > + *
> > + * Returns:
> > + *	always 0
> 
> So why not void?

Same reason; struct file_operations calls for the function prototype
returning an int.

> 
> ...
> > + * pti_console_setup()-  Initialize console variables used by the driver.
> > + *
> > + * @c:     Not used.
> > + * @opts:  Not used.
> > + *
> > + * Returns:
> > + *	always 0.
> 
> Why not void?

Same reason; the kernel driver prototype function calls for an int
return value.

> 
> 
> ...
> > + * pti_port_activate()- Used to start/initialize any items upon
> > + * first opening of tty_port().
> > + *
> > + * @port- The tty port number of the PTI device.
> > + * @tty-  The tty struct associated with this device.
> > + *
> > + * Returns:
> > + *	always returns 0
> 
> Shouldn't it just return void then?

Same reason as above.

> 
> 

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[J Freyensee]

On Sun, 2011-04-24 at 03:08 +0200, Jesper Juhl wrote:
> On Sun, 24 Apr 2011, Jesper Juhl wrote:
> 
> > On Fri, 22 Apr 2011, james_p_freyensee@linux.intel.com wrote:
> > 
> ...
> > > +static void pti_tty_cleanup(struct tty_struct *tty)
> > > +{
> > > +	struct pti_tty *pti_tty_data;
> > > +	struct pti_masterchannel *mc;
> > > +
> > > +	pti_tty_data = tty->driver_data;
> > > +
> > > +	if (pti_tty_data != NULL) {
> > > +		mc = pti_tty_data->mc;
> > > +		pti_release_masterchannel(mc);
> > > +		pti_tty_data->mc = NULL;
> > > +	}
> > > +
> > > +	if (pti_tty_data != NULL)
> > > +		kfree(pti_tty_data);
> > > +
> > > +	tty->driver_data = NULL;
> > > +}
> > 
> > How about this instead?
> > 
> > static void pti_tty_cleanup(struct tty_struct *tty)
> > {
> >      if (!tty->driver_data)
> >              return;
> >      pti_release_masterchannel(tty->driver_data->mc);

I like this suggestion.  I'll incorporate this.  

> >      kfree(tty->driver_data);

I'm no means an expert in the kernel, but I assume kfree() is like C
free(), that it's a nop if it receives a NULL value?

> > }
> > 
> I meant to say :
> 
> static void pti_tty_cleanup(struct tty_struct *tty)
> {
>      if (!tty->driver_data)
>              return;
>      pti_release_masterchannel(tty->driver_data->mc);
>      kfree(tty->driver_data);
>      tty->driver_data = NULL
> }   
> 
> 

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[Jesper Juhl]

On Sun, 24 Apr 2011, Jesper Juhl wrote:

> On Fri, 22 Apr 2011, james_p_freyensee@linux.intel.com wrote:
> 
...
> > +static void pti_tty_cleanup(struct tty_struct *tty)
> > +{
> > +	struct pti_tty *pti_tty_data;
> > +	struct pti_masterchannel *mc;
> > +
> > +	pti_tty_data = tty->driver_data;
> > +
> > +	if (pti_tty_data != NULL) {
> > +		mc = pti_tty_data->mc;
> > +		pti_release_masterchannel(mc);
> > +		pti_tty_data->mc = NULL;
> > +	}
> > +
> > +	if (pti_tty_data != NULL)
> > +		kfree(pti_tty_data);
> > +
> > +	tty->driver_data = NULL;
> > +}
> 
> How about this instead?
> 
> static void pti_tty_cleanup(struct tty_struct *tty)
> {
>      if (!tty->driver_data)
>              return;
>      pti_release_masterchannel(tty->driver_data->mc);
>      kfree(tty->driver_data);
> }
> 
I meant to say :

static void pti_tty_cleanup(struct tty_struct *tty)
{
     if (!tty->driver_data)
             return;
     pti_release_masterchannel(tty->driver_data->mc);
     kfree(tty->driver_data);
     tty->driver_data = NULL
}   


-- 
Jesper Juhl <jj@chaosbits.net>       http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
Plain text mails only, please.

Re: [PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[Jesper Juhl]

On Fri, 22 Apr 2011, james_p_freyensee@linux.intel.com wrote:

> From: J Freyensee <james_p_freyensee@linux.intel.com>
> 
> The PTI (Parallel Trace Interface) driver directs
> trace data routed from various parts in the system out
> through an Intel Penwell PTI port and out of the mobile
> device for analysis with a debugging tool (Lauterbach or Fido).
> Though n_tracesink and n_tracerouter line discipline drivers
> are used to extract modem tracing data to the PTI driver
> and other parts of an Intel mobile solution, the PTI driver
> can be used independent of n_tracesink and n_tracerouter.
> 
> You should select this driver if the target kernel is meant for
> an Intel Atom (non-netbook) mobile device containing a MIPI
> P1149.7 standard implementation.
> 
> Signed-off-by: J Freyensee <james_p_freyensee@linux.intel.com>

A few comments below.

...
> +#define DRIVERNAME		"pti"
> +#define PCINAME			"pciPTI"
> +#define TTYNAME			"ttyPTI"
> +#define CHARNAME		"pti"
> +#define PTITTY_MINOR_START	0
> +#define PTITTY_MINOR_NUM	2
> +#define MAX_APP_IDS		16   /* 128 channel ids / u8 bit size */
> +#define MAX_OS_IDS		16   /* 128 channel ids / u8 bit size */
> +#define MAX_MODEM_IDS		16   /* 128 channel ids / u8 bit size */
> +#define MODEM_BASE_ID		71   /* modem master ID address    */
...

Would be nice if the values of these defines would line up nicely.


...
> +static struct pci_device_id pci_ids[] __devinitconst = {
> +		{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x82B) },
> +		{0}
...

Why are there spaces after the opening { and before the closing } for the 
first entry, but not the second. Looks like you need to pick a 
consistent style.


> + *  regroup the appropriate message segments together reconstituting each
> + *  message.
> + */
> +static void pti_write_to_aperture(struct pti_masterchannel *mc,
> +				  u8 *buf,
> +				  int len)
> +{
> +	int dwordcnt, final, i;
> +	u32 ptiword;
> +	u8 *p;
> +	u32 __iomem *aperture;
> +
> +	p = buf;
...

Perhaps save a few lines by doing

static void pti_write_to_aperture(struct pti_masterchannel *mc,
                               u8 *buf,
                               int len)
{
     int dwordcnt, final, i;
     u32 ptiword;
     u32 __iomem *aperture;
     u8 *p = buf;


...
> +void pti_writedata(struct pti_masterchannel *mc, u8 *buf, int count)
> +{
> +	/*
> +	 * since this function is exported, this is treated like an
> +	 * API function, thus, all parameters should
> +	 * be checked for validity.
> +	 */
> +	if ((mc != NULL) && (buf != NULL) && (count > 0))
> +		pti_write_to_aperture(mc, buf, count);
> +	return;
...

Pointless return; statement.


...
> +static void __devexit pti_pci_remove(struct pci_dev *pdev)
> +{
> +	struct pti_dev *drv_data;
> +
> +	drv_data = pci_get_drvdata(pdev);
> +	if (drv_data != NULL) {

Perhaps

static void __devexit pti_pci_remove(struct pci_dev *pdev)
{
     struct pti_dev *drv_data = pci_get_drvdata(pdev);
     
     if (drv_data) {


...
> +static int pti_tty_driver_open(struct tty_struct *tty, struct file *filp)
> +{
> +	int ret = 0;
> +
> +	/*
> +	 * we actually want to allocate a new channel per open, per
> +	 * system arch.  HW gives more than plenty channels for a single
> +	 * system task to have its own channel to write trace data. This
> +	 * also removes a locking requirement for the actual write
> +	 * procedure.
> +	 */
> +	ret = tty_port_open(&drv_data->port, tty, filp);
> +
> +	return ret;
> +}
...

Why not get rid of the pointless 'ret' variable and simplify this down to

static int pti_tty_driver_open(struct tty_struct *tty, struct file *filp)
{     
     /*
      * we actually want to allocate a new channel per open, per
      * system arch.  HW gives more than plenty channels for a single
      * system task to have its own channel to write trace data. This
      * also removes a locking requirement for the actual write
      * procedure.
      */
     return tty_port_open(&drv_data->port, tty, filp);
}

??


...
> +static void pti_tty_driver_close(struct tty_struct *tty, struct file *filp)
> +{
> +	tty_port_close(&drv_data->port, tty, filp);
> +
> +	return;
> +}

Just kill that superfluous return statement.


...
> +static void pti_tty_cleanup(struct tty_struct *tty)
> +{
> +	struct pti_tty *pti_tty_data;
> +	struct pti_masterchannel *mc;
> +
> +	pti_tty_data = tty->driver_data;
> +
> +	if (pti_tty_data != NULL) {
> +		mc = pti_tty_data->mc;
> +		pti_release_masterchannel(mc);
> +		pti_tty_data->mc = NULL;
> +	}
> +
> +	if (pti_tty_data != NULL)
> +		kfree(pti_tty_data);
> +
> +	tty->driver_data = NULL;
> +}

How about this instead?

static void pti_tty_cleanup(struct tty_struct *tty)
{
     if (!tty->driver_data)
             return;
     pti_release_masterchannel(tty->driver_data->mc);
     kfree(tty->driver_data);
}

...
> +static int pti_tty_driver_write(struct tty_struct *tty,
> +	const unsigned char *buf, int len)
> +{
> +	struct pti_masterchannel *mc;
> +	struct pti_tty *pti_tty_data;
> +
> +	pti_tty_data = tty->driver_data;
> +	mc = pti_tty_data->mc;
> +	pti_write_to_aperture(mc, (u8 *)buf, len);
> +
> +	return len;
> +}

I'd like to suggest this as an alternative:

static int pti_tty_driver_write(struct tty_struct *tty,
     const unsigned char *buf, int len)
{
     pti_write_to_aperture(tty->driver_data->mc, (u8 *)buf, len);
     return len;
}


..
> +static int pti_char_open(struct inode *inode, struct file *filp)
> +{
> +	struct pti_masterchannel *mc;
> +
> +	mc = pti_request_masterchannel(0);
> +	if (mc == NULL)
> +		return -ENOMEM;
> +	filp->private_data = mc;
> +	return 0;
> +}

Ok, so I admit that I haven't looked to check if it's actually important 
that filp->private_data does not get overwritten if 
pti_request_masterchannel() returns NULL, but if we assume that it is not 
important, then this would be an improvement IMHO:

static int pti_char_open(struct inode *inode, struct file *filp)
{
     filp->private_data = pti_request_masterchannel(0);
     if (!filp->private_data)
             return -ENOMEM; 
     return 0;
}


...
> +
> +/**
> + * pti_char_release()-  Close a char channel to the PTI device. Part
> + * of the misc device implementation.
> + *
> + * @inode: Not used in this implementaiton.
> + * @filp:  Contains private_data that contains the master, channel
> + *         ID to be released by the PTI device.
> + *
> + * Returns:
> + *	always 0

Why not void then?


> +	pti_release_masterchannel(filp->private_data);
> +	return 0;
> +}
> +
> +/**
> + * pti_char_write()-  Write trace debugging data through the char
> + * interface to the PTI HW.  Part of the misc device implementation.
> + *
> + * @filp:  Contains private data which is used to obtain
> + *         master, channel write ID.
> + * @data:  trace data to be written.
> + * @len:   # of byte to write.
> + * @ppose: Not used in this function implementation.
> + *
> + * Returns:
> + *	int, # of bytes written
> + *	otherwise, error value
> + *
> + * Notes: From side discussions with Alan Cox and experimenting
> + * with PTI debug HW like Nokia's Fido box and Lauterbach
> + * devices, 8192 byte write buffer used by USER_COPY_SIZE was
> + * deemed an appropriate size for this type of usage with
> + * debugging HW.
> + */
> +static ssize_t pti_char_write(struct file *filp, const char __user *data,
> +			      size_t len, loff_t *ppose)
> +{
> +	struct pti_masterchannel *mc;
> +	void *kbuf;
> +	const char __user *tmp;
> +	size_t size = USER_COPY_SIZE, n = 0;

It would be nice to declare these two variables on two sepperate lines 
IMO.

> +
> +	tmp = data;
> +	mc = filp->private_data;
> +
> +	kbuf = kmalloc(size, GFP_KERNEL);
> +	if (kbuf == NULL)  {
> +		pr_err("%s(%d): buf allocation failed\n",
> +			__func__, __LINE__);
> +		return 0;

Shouldn't you be returning -ENOMEM here?

> +	}
> +
> +	do {
> +		if (len - n > USER_COPY_SIZE)
> +			size = USER_COPY_SIZE;
> +		else
> +			size = len - n;
> +
> +		if (copy_from_user(kbuf, tmp, size)) {
> +			kfree(kbuf);
> +			return n ? n : -EFAULT;
> +		}
> +
> +		pti_write_to_aperture(mc, kbuf, size);
> +		n  += size;
> +		tmp += size;
> +
> +	} while (len > n);
> +
> +	kfree(kbuf);
> +	kbuf = NULL;
> +

 kbuff is a local variable. What's the point in assigning NULL to it just 
before you return? Just get rid of that silly assignment.


...
> + * pti_char_release()-  Close a char channel to the PTI device. Part
> + * of the misc device implementation.
> + *
> + * @inode: Not used in this implementaiton.
> + * @filp:  Contains private_data that contains the master, channel
> + *         ID to be released by the PTI device.
> + *
> + * Returns:
> + *	always 0

So why not void?

...
> + * pti_console_setup()-  Initialize console variables used by the driver.
> + *
> + * @c:     Not used.
> + * @opts:  Not used.
> + *
> + * Returns:
> + *	always 0.

Why not void?


...
> + * pti_port_activate()- Used to start/initialize any items upon
> + * first opening of tty_port().
> + *
> + * @port- The tty port number of the PTI device.
> + * @tty-  The tty struct associated with this device.
> + *
> + * Returns:
> + *	always returns 0

Shouldn't it just return void then?


-- 
Jesper Juhl <jj@chaosbits.net>       http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
Plain text mails only, please.

[PATCH 3/4] Intel PTI implementaiton of MIPI 1149.7.

[james_p_freyensee]

From: J Freyensee <james_p_freyensee@linux.intel.com>

The PTI (Parallel Trace Interface) driver directs
trace data routed from various parts in the system out
through an Intel Penwell PTI port and out of the mobile
device for analysis with a debugging tool (Lauterbach or Fido).
Though n_tracesink and n_tracerouter line discipline drivers
are used to extract modem tracing data to the PTI driver
and other parts of an Intel mobile solution, the PTI driver
can be used independent of n_tracesink and n_tracerouter.

You should select this driver if the target kernel is meant for
an Intel Atom (non-netbook) mobile device containing a MIPI
P1149.7 standard implementation.

Signed-off-by: J Freyensee <james_p_freyensee@linux.intel.com>
---
 drivers/misc/Kconfig  |   13 +
 drivers/misc/Makefile |    1 +
 drivers/misc/pti.c    |  994 +++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/pti.h   |   42 ++
 4 files changed, 1050 insertions(+), 0 deletions(-)
 create mode 100644 drivers/misc/pti.c
 create mode 100644 include/linux/pti.h

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 4e007c6..e87babd 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -144,6 +144,19 @@ config PHANTOM
 	  If you choose to build module, its name will be phantom. If unsure,
 	  say N here.
 
+config INTEL_MID_PTI
+	tristate "Parallel Trace Interface for MIPI P1149.7 cJTAG standard"
+	default n
+	help
+	  The PTI (Parallel Trace Interface) driver directs
+	  trace data routed from various parts in the system out
+	  through an Intel Penwell PTI port and out of the mobile
+	  device for analysis with a debugging tool (Lauterbach or Fido).
+
+	  You should select this driver if the target kernel is meant for
+	  an Intel Atom (non-netbook) mobile device containing a MIPI
+	  P1149.7 standard implementation.
+
 config SGI_IOC4
 	tristate "SGI IOC4 Base IO support"
 	depends on PCI
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index f546860..662aa3c 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_IBM_ASM)		+= ibmasm/
 obj-$(CONFIG_AD525X_DPOT)	+= ad525x_dpot.o
 obj-$(CONFIG_AD525X_DPOT_I2C)	+= ad525x_dpot-i2c.o
 obj-$(CONFIG_AD525X_DPOT_SPI)	+= ad525x_dpot-spi.o
+0bj-$(CONFIG_INTEL_MID_PTI)	+= pti.o
 obj-$(CONFIG_ATMEL_PWM)		+= atmel_pwm.o
 obj-$(CONFIG_ATMEL_SSC)		+= atmel-ssc.o
 obj-$(CONFIG_ATMEL_TCLIB)	+= atmel_tclib.o
diff --git a/drivers/misc/pti.c b/drivers/misc/pti.c
new file mode 100644
index 0000000..061c3a2
--- /dev/null
+++ b/drivers/misc/pti.c
@@ -0,0 +1,994 @@
+/*
+ *  pti.c - PTI driver for cJTAG data extration
+ *
+ *  Copyright (C) Intel 2010
+ *
+ * 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.
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/console.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/pci.h>
+#include <linux/mutex.h>
+#include <linux/miscdevice.h>
+#include <linux/pti.h>
+
+#define DRIVERNAME		"pti"
+#define PCINAME			"pciPTI"
+#define TTYNAME			"ttyPTI"
+#define CHARNAME		"pti"
+#define PTITTY_MINOR_START	0
+#define PTITTY_MINOR_NUM	2
+#define MAX_APP_IDS		16   /* 128 channel ids / u8 bit size */
+#define MAX_OS_IDS		16   /* 128 channel ids / u8 bit size */
+#define MAX_MODEM_IDS		16   /* 128 channel ids / u8 bit size */
+#define MODEM_BASE_ID		71   /* modem master ID address    */
+#define CONTROL_ID		72   /* control master ID address  */
+#define CONSOLE_ID		73   /* console master ID address  */
+#define OS_BASE_ID		74   /* base OS master ID address  */
+#define APP_BASE_ID		80   /* base App master ID address */
+#define CONTROL_FRAME_LEN	32   /* PTI control frame maximum size */
+#define USER_COPY_SIZE		8192 /* 8Kb buffer for user space copy */
+#define APERTURE_14		0x3800000 /* offset to first OS write addr */
+#define APERTURE_LEN		0x400000  /* address length */
+
+struct pti_tty {
+	struct pti_masterchannel *mc;
+};
+
+struct pti_dev {
+	struct tty_port port;
+	unsigned long pti_addr;
+	unsigned long aperture_base;
+	void __iomem *pti_ioaddr;
+	u8 ia_app[MAX_APP_IDS];
+	u8 ia_os[MAX_OS_IDS];
+	u8 ia_modem[MAX_MODEM_IDS];
+};
+
+/*
+ * This protects access to ia_app, ia_os, and ia_modem,
+ * which keeps track of channels allocated in
+ * an aperture write id.
+ */
+static DEFINE_MUTEX(alloclock);
+
+static struct pci_device_id pci_ids[] __devinitconst = {
+		{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x82B) },
+		{0}
+};
+
+static struct tty_driver *pti_tty_driver;
+static struct pti_dev *drv_data;
+
+static unsigned int pti_console_channel;
+static unsigned int pti_control_channel;
+
+/**
+ *  pti_write_to_aperture()- The private write function to PTI HW.
+ *
+ *  @mc: The 'aperture'. It's part of a write address that holds
+ *       a master and channel ID.
+ *  @buf: Data being written to the HW that will ultimately be seen
+ *        in a debugging tool (Fido, Lauterbach).
+ *  @len: Size of buffer.
+ *
+ *  Since each aperture is specified by a unique
+ *  master/channel ID, no two processes will be writing
+ *  to the same aperture at the same time so no lock is required. The
+ *  PTI-Output agent will send these out in the order that they arrived, and
+ *  thus, it will intermix these messages. The debug tool can then later
+ *  regroup the appropriate message segments together reconstituting each
+ *  message.
+ */
+static void pti_write_to_aperture(struct pti_masterchannel *mc,
+				  u8 *buf,
+				  int len)
+{
+	int dwordcnt, final, i;
+	u32 ptiword;
+	u8 *p;
+	u32 __iomem *aperture;
+
+	p = buf;
+
+	/*
+	 * calculate the aperture offset from the base using the master and
+	 * channel id's.
+	 */
+	aperture = drv_data->pti_ioaddr + (mc->master << 15)
+		+ (mc->channel << 8);
+
+	dwordcnt = len >> 2;
+	final = len - (dwordcnt << 2);	    /* final = trailing bytes    */
+	if (final == 0 && dwordcnt != 0) {  /* always need a final dword */
+		final += 4;
+		dwordcnt--;
+	}
+
+	for (i = 0; i < dwordcnt; i++) {
+		ptiword = be32_to_cpu(*(u32 *)p);
+		p += 4;
+		iowrite32(ptiword, aperture);
+	}
+
+	aperture += PTI_LASTDWORD_DTS;	/* adding DTS signals that is EOM */
+
+	ptiword = 0;
+	for (i = 0; i < final; i++)
+		ptiword |= *p++ << (24-(8*i));
+
+	iowrite32(ptiword, aperture);
+	return;
+}
+
+/**
+ *  pti_control_frame_built_and_sent()- control frame build and send function.
+ *
+ *  @mc: The master / channel structure on which the function
+ *       built a control frame.
+ *
+ *  To be able to post process the PTI contents on host side, a control frame
+ *  is added before sending any PTI content. So the host side knows on
+ *  each PTI frame the name of the thread using a dedicated master / channel.
+ *  The thread name is retrieved from the 'current' global variable.
+ *  This function builds this frame and sends it to a master ID CONTROL_ID.
+ *  The overhead is only 32 bytes since the driver only writes to HW
+ *  in 32 byte chunks.
+ */
+
+static void pti_control_frame_built_and_sent(struct pti_masterchannel *mc)
+{
+	struct pti_masterchannel mccontrol = {.master = CONTROL_ID,
+					      .channel = 0};
+	const char *control_format = "%3d %3d %s";
+	u8 control_frame[CONTROL_FRAME_LEN];
+
+	/*
+	 * Since we access the comm member in current's task_struct,
+	 * we only need to be as large as what 'comm' in that
+	 * structure is.
+	 */
+	char comm[TASK_COMM_LEN];
+
+	if (!in_interrupt())
+		get_task_comm(comm, current);
+	else
+		strncpy(comm, "Interrupt", TASK_COMM_LEN);
+
+	/* Absolutely ensure our buffer is zero terminated. */
+	comm[TASK_COMM_LEN-1] = 0;
+
+	mccontrol.channel = pti_control_channel;
+	pti_control_channel = (pti_control_channel + 1) & 0x7f;
+
+	snprintf(control_frame, CONTROL_FRAME_LEN, control_format, mc->master,
+		mc->channel, comm);
+	pti_write_to_aperture(&mccontrol, control_frame, strlen(control_frame));
+}
+
+/**
+ *  pti_write_full_frame_to_aperture()- high level function to
+ *					write to PTI.
+ *
+ *  @mc:  The 'aperture'. It's part of a write address that holds
+ *        a master and channel ID.
+ *  @buf: Data being written to the HW that will ultimately be seen
+ *        in a debugging tool (Fido, Lauterbach).
+ *  @len: Size of buffer.
+ *
+ *  All threads sending data (either console, user space application, ...)
+ *  are calling the high level function to write to PTI meaning that it is
+ *  possible to add a control frame before sending the content.
+ */
+static void pti_write_full_frame_to_aperture(struct pti_masterchannel *mc,
+						const unsigned char *buf,
+						int len)
+{
+	pti_control_frame_built_and_sent(mc);
+	pti_write_to_aperture(mc, (u8 *)buf, len);
+}
+
+/**
+ * get_id()- Allocate a master and channel ID.
+ *
+ * @id_array: an array of bits representing what channel
+ *            id's are allocated for writing.
+ * @max_ids:  The max amount of available write IDs to use.
+ * @base_id:  The starting SW channel ID, based on the Intel
+ *            PTI arch.
+ *
+ * Returns:
+ *	pti_masterchannel struct with master, channel ID address
+ *	0 for error
+ *
+ * Each bit in the arrays ia_app and ia_os correspond to a master and
+ * channel id. The bit is one if the id is taken and 0 if free. For
+ * every master there are 128 channel id's.
+ */
+static struct pti_masterchannel *get_id(u8 *id_array, int max_ids, int base_id)
+{
+	struct pti_masterchannel *mc;
+	int i, j, mask;
+
+	mc = kmalloc(sizeof(struct pti_masterchannel), GFP_KERNEL);
+	if (mc == NULL)
+		return NULL;
+
+	/* look for a byte with a free bit */
+	for (i = 0; i < max_ids; i++)
+		if (id_array[i] != 0xff)
+			break;
+	if (i == max_ids) {
+		kfree(mc);
+		return NULL;
+	}
+	/* find the bit in the 128 possible channel opportunities */
+	mask = 0x80;
+	for (j = 0; j < 8; j++) {
+		if ((id_array[i] & mask) == 0)
+			break;
+		mask >>= 1;
+	}
+
+	/* grab it */
+	id_array[i] |= mask;
+	mc->master  = base_id;
+	mc->channel = ((i & 0xf)<<3) + j;
+	/* write new master Id / channel Id allocation to channel control */
+	pti_control_frame_built_and_sent(mc);
+	return mc;
+}
+
+/*
+ * The following three functions:
+ * pti_request_mastercahannel(), mipi_release_masterchannel()
+ * and pti_writedata() are an API for other kernel drivers to
+ * access PTI.
+ */
+
+/**
+ * pti_request_masterchannel()- Kernel API function used to allocate
+ *				a master, channel ID address
+ *				to write to PTI HW.
+ *
+ * @type: 0- request Application  master, channel aperture ID write address.
+ *        1- request OS master, channel aperture ID write
+ *           address.
+ *        2- request Modem master, channel aperture ID
+ *           write address.
+ *        Other values, error.
+ *
+ * Returns:
+ *	pti_masterchannel struct
+ *	0 for error
+ */
+struct pti_masterchannel *pti_request_masterchannel(u8 type)
+{
+	struct pti_masterchannel *mc;
+
+	mutex_lock(&alloclock);
+
+	switch (type) {
+
+	case 0:
+		mc = get_id(drv_data->ia_app, MAX_APP_IDS, APP_BASE_ID);
+		break;
+
+	case 1:
+		mc = get_id(drv_data->ia_os, MAX_OS_IDS, OS_BASE_ID);
+		break;
+
+	case 2:
+		mc = get_id(drv_data->ia_modem, MAX_MODEM_IDS, MODEM_BASE_ID);
+		break;
+	default:
+		mc = NULL;
+	}
+
+	mutex_unlock(&alloclock);
+	return mc;
+}
+EXPORT_SYMBOL_GPL(pti_request_masterchannel);
+
+/**
+ * pti_release_masterchannel()- Kernel API function used to release
+ *				a master, channel ID address
+ *				used to write to PTI HW.
+ *
+ * @mc: master, channel apeture ID address to be released.
+ */
+void pti_release_masterchannel(struct pti_masterchannel *mc)
+{
+	u8 master, channel, i;
+
+	mutex_lock(&alloclock);
+
+	if (mc) {
+		master = mc->master;
+		channel = mc->channel;
+
+		if (master == APP_BASE_ID) {
+			i = channel >> 3;
+			drv_data->ia_app[i] &=  ~(0x80>>(channel & 0x7));
+		} else if (master == OS_BASE_ID) {
+			i = channel >> 3;
+			drv_data->ia_os[i] &= ~(0x80>>(channel & 0x7));
+		} else {
+			i = channel >> 3;
+			drv_data->ia_modem[i] &= ~(0x80>>(channel & 0x7));
+		}
+
+		kfree(mc);
+	}
+
+	mutex_unlock(&alloclock);
+}
+EXPORT_SYMBOL_GPL(pti_release_masterchannel);
+
+/**
+ * pti_writedata()- Kernel API function used to write trace
+ *                  debugging data to PTI HW.
+ *
+ * @mc:    Master, channel aperture ID address to write to.
+ *         Null value will return with no write occurring.
+ * @buf:   Trace debuging data to write to the PTI HW.
+ *         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.
+ */
+void pti_writedata(struct pti_masterchannel *mc, u8 *buf, int count)
+{
+	/*
+	 * since this function is exported, this is treated like an
+	 * API function, thus, all parameters should
+	 * be checked for validity.
+	 */
+	if ((mc != NULL) && (buf != NULL) && (count > 0))
+		pti_write_to_aperture(mc, buf, count);
+	return;
+}
+EXPORT_SYMBOL_GPL(pti_writedata);
+
+/**
+ * pti_pci_remove()- Driver exit method to remove PTI from
+ *		   PCI bus.
+ * @pdev: variable containing pci info of PTI.
+ */
+static void __devexit pti_pci_remove(struct pci_dev *pdev)
+{
+	struct pti_dev *drv_data;
+
+	drv_data = pci_get_drvdata(pdev);
+	if (drv_data != NULL) {
+		pci_iounmap(pdev, drv_data->pti_ioaddr);
+		pci_set_drvdata(pdev, NULL);
+		kfree(drv_data);
+		pci_release_region(pdev, 1);
+		pci_disable_device(pdev);
+	}
+}
+
+/*
+ * for the tty_driver_*() basic function descriptions, see tty_driver.h.
+ * Specific header comments made for PTI-related specifics.
+ */
+
+/**
+ * pti_tty_driver_open()- Open an Application master, channel aperture
+ * ID to the PTI device via tty device.
+ *
+ * @tty: tty interface.
+ * @filp: filp interface pased to tty_port_open() call.
+ *
+ * Returns:
+ *	int, 0 for success
+ *	otherwise, fail value
+ *
+ * The main purpose of using the tty device interface is for
+ * each tty port to have a unique PTI write aperture.  In an
+ * example use case, ttyPTI0 gets syslogd and an APP aperture
+ * ID and ttyPTI1 is where the n_tracesink ldisc hooks to route
+ * modem messages into PTI.  Modem trace data does not have to
+ * go to ttyPTI1, but ttyPTI0 and ttyPTI1 do need to be distinct
+ * master IDs.  These messages go through the PTI HW and out of
+ * the handheld platform and to the Fido/Lauterbach device.
+ */
+static int pti_tty_driver_open(struct tty_struct *tty, struct file *filp)
+{
+	int ret = 0;
+
+	/*
+	 * we actually want to allocate a new channel per open, per
+	 * system arch.  HW gives more than plenty channels for a single
+	 * system task to have its own channel to write trace data. This
+	 * also removes a locking requirement for the actual write
+	 * procedure.
+	 */
+	ret = tty_port_open(&drv_data->port, tty, filp);
+
+	return ret;
+}
+
+/**
+ * pti_tty_driver_close()- close tty device and release Application
+ * master, channel aperture ID to the PTI device via tty device.
+ *
+ * @tty: tty interface.
+ * @filp: filp interface pased to tty_port_close() call.
+ *
+ * The main purpose of using the tty device interface is to route
+ * syslog daemon messages to the PTI HW and out of the handheld platform
+ * and to the Fido/Lauterbach device.
+ */
+static void pti_tty_driver_close(struct tty_struct *tty, struct file *filp)
+{
+	tty_port_close(&drv_data->port, tty, filp);
+
+	return;
+}
+
+/**
+ * pti_tty_intstall()- Used to set up specific master-channels
+ *		       to tty ports for organizational purposes when
+ *		       tracing viewed from debuging tools.
+ *
+ * @driver: tty driver information.
+ * @tty: tty struct containing pti information.
+ *
+ * Returns:
+ *	0 for success
+ *	otherwise, error
+ */
+static int pti_tty_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	int idx = tty->index;
+	struct pti_tty *pti_tty_data;
+	struct pti_masterchannel *mc;
+	int ret = tty_init_termios(tty);
+
+	if (ret == 0) {
+		tty_driver_kref_get(driver);
+		tty->count++;
+		driver->ttys[idx] = tty;
+
+		pti_tty_data = kmalloc(sizeof(struct pti_tty), GFP_KERNEL);
+		if (pti_tty_data == NULL)
+			return -ENOMEM;
+
+		tty->driver_data = pti_tty_data;
+
+		if (idx == PTITTY_MINOR_START)
+			mc = pti_request_masterchannel(0);
+		else
+			mc = pti_request_masterchannel(2);
+
+		if (mc == NULL)
+			return -ENXIO;
+
+		pti_tty_data->mc = mc;
+	}
+
+	return ret;
+}
+
+/**
+ * pti_tty_cleanup()- Used to de-allocate master-channel resources
+ *		      tied to tty's of this driver.
+ *
+ * @tty: tty struct containing pti information.
+ */
+static void pti_tty_cleanup(struct tty_struct *tty)
+{
+	struct pti_tty *pti_tty_data;
+	struct pti_masterchannel *mc;
+
+	pti_tty_data = tty->driver_data;
+
+	if (pti_tty_data != NULL) {
+		mc = pti_tty_data->mc;
+		pti_release_masterchannel(mc);
+		pti_tty_data->mc = NULL;
+	}
+
+	if (pti_tty_data != NULL)
+		kfree(pti_tty_data);
+
+	tty->driver_data = NULL;
+}
+
+/**
+ * pti_tty_driver_write()-  Write trace debugging data through the char
+ * interface to the PTI HW.  Part of the misc device implementation.
+ *
+ * @filp: Contains private data which is used to obtain
+ *        master, channel write ID.
+ * @data: trace data to be written.
+ * @len:  # of byte to write.
+ *
+ * Returns:
+ *	int, # of bytes written
+ *	otherwise, error
+ */
+static int pti_tty_driver_write(struct tty_struct *tty,
+	const unsigned char *buf, int len)
+{
+	struct pti_masterchannel *mc;
+	struct pti_tty *pti_tty_data;
+
+	pti_tty_data = tty->driver_data;
+	mc = pti_tty_data->mc;
+	pti_write_to_aperture(mc, (u8 *)buf, len);
+
+	return len;
+}
+
+/**
+ * pti_tty_write_room()- Always returns 2048.
+ *
+ * @tty: contains tty info of the pti driver.
+ */
+static int pti_tty_write_room(struct tty_struct *tty)
+{
+	return 2048;
+}
+
+/**
+ * pti_char_open()- Open an Application master, channel aperture
+ * ID to the PTI device. Part of the misc device implementation.
+ *
+ * @inode: not used.
+ * @filp:  Output- will have a masterchannel struct set containing
+ *                 the allocated application PTI aperture write address.
+ *
+ * Returns:
+ *	int, 0 for success
+ *	otherwise, a fail value
+ */
+static int pti_char_open(struct inode *inode, struct file *filp)
+{
+	struct pti_masterchannel *mc;
+
+	mc = pti_request_masterchannel(0);
+	if (mc == NULL)
+		return -ENOMEM;
+	filp->private_data = mc;
+	return 0;
+}
+
+/**
+ * pti_char_release()-  Close a char channel to the PTI device. Part
+ * of the misc device implementation.
+ *
+ * @inode: Not used in this implementaiton.
+ * @filp:  Contains private_data that contains the master, channel
+ *         ID to be released by the PTI device.
+ *
+ * Returns:
+ *	always 0
+ */
+static int pti_char_release(struct inode *inode, struct file *filp)
+{
+	pti_release_masterchannel(filp->private_data);
+	return 0;
+}
+
+/**
+ * pti_char_write()-  Write trace debugging data through the char
+ * interface to the PTI HW.  Part of the misc device implementation.
+ *
+ * @filp:  Contains private data which is used to obtain
+ *         master, channel write ID.
+ * @data:  trace data to be written.
+ * @len:   # of byte to write.
+ * @ppose: Not used in this function implementation.
+ *
+ * Returns:
+ *	int, # of bytes written
+ *	otherwise, error value
+ *
+ * Notes: From side discussions with Alan Cox and experimenting
+ * with PTI debug HW like Nokia's Fido box and Lauterbach
+ * devices, 8192 byte write buffer used by USER_COPY_SIZE was
+ * deemed an appropriate size for this type of usage with
+ * debugging HW.
+ */
+static ssize_t pti_char_write(struct file *filp, const char __user *data,
+			      size_t len, loff_t *ppose)
+{
+	struct pti_masterchannel *mc;
+	void *kbuf;
+	const char __user *tmp;
+	size_t size = USER_COPY_SIZE, n = 0;
+
+	tmp = data;
+	mc = filp->private_data;
+
+	kbuf = kmalloc(size, GFP_KERNEL);
+	if (kbuf == NULL)  {
+		pr_err("%s(%d): buf allocation failed\n",
+			__func__, __LINE__);
+		return 0;
+	}
+
+	do {
+		if (len - n > USER_COPY_SIZE)
+			size = USER_COPY_SIZE;
+		else
+			size = len - n;
+
+		if (copy_from_user(kbuf, tmp, size)) {
+			kfree(kbuf);
+			return n ? n : -EFAULT;
+		}
+
+		pti_write_to_aperture(mc, kbuf, size);
+		n  += size;
+		tmp += size;
+
+	} while (len > n);
+
+	kfree(kbuf);
+	kbuf = NULL;
+
+	return len;
+}
+
+static const struct tty_operations pti_tty_driver_ops = {
+	.open		= pti_tty_driver_open,
+	.close		= pti_tty_driver_close,
+	.write		= pti_tty_driver_write,
+	.write_room	= pti_tty_write_room,
+	.install	= pti_tty_install,
+	.cleanup	= pti_tty_cleanup
+};
+
+static const struct file_operations pti_char_driver_ops = {
+	.owner		= THIS_MODULE,
+	.write		= pti_char_write,
+	.open		= pti_char_open,
+	.release	= pti_char_release,
+};
+
+static struct miscdevice pti_char_driver = {
+	.minor		= MISC_DYNAMIC_MINOR,
+	.name		= CHARNAME,
+	.fops		= &pti_char_driver_ops
+};
+
+/**
+ * pti_char_release()-  Close a char channel to the PTI device. Part
+ * of the misc device implementation.
+ *
+ * @inode: Not used in this implementaiton.
+ * @filp:  Contains private_data that contains the master, channel
+ *         ID to be released by the PTI device.
+ *
+ * Returns:
+ *	always 0
+ */
+static void pti_console_write(struct console *c, const char *buf, unsigned len)
+{
+	static struct pti_masterchannel mc = {.master  = CONSOLE_ID,
+					      .channel = 0};
+
+	mc.channel = pti_console_channel;
+	pti_console_channel = (pti_console_channel + 1) & 0x7f;
+
+	pti_write_full_frame_to_aperture(&mc, buf, len);
+}
+
+/**
+ * pti_console_device()-  Return the driver tty structure and set the
+ *			  associated index implementation.
+ *
+ * @c:     Console device of the driver.
+ * @index: index associated with c.
+ *
+ * Returns:
+ *	always value of pti_tty_driver structure when this function
+ *	is called.
+ */
+static struct tty_driver *pti_console_device(struct console *c, int *index)
+{
+	*index = c->index;
+	return pti_tty_driver;
+}
+
+/**
+ * pti_console_setup()-  Initialize console variables used by the driver.
+ *
+ * @c:     Not used.
+ * @opts:  Not used.
+ *
+ * Returns:
+ *	always 0.
+ */
+static int pti_console_setup(struct console *c, char *opts)
+{
+	pti_console_channel = 0;
+	pti_control_channel = 0;
+	return 0;
+}
+
+/*
+ * pti_console struct, used to capture OS printk()'s and shift
+ * out to the PTI device for debugging.  This cannot be
+ * enabled upon boot because of the possibility of eating
+ * any serial console printk's (race condition discovered).
+ * The console should be enabled upon when the tty port is
+ * used for the first time.  Since the primary purpose for
+ * the tty port is to hook up syslog to it, the tty port
+ * will be open for a really long time.
+ */
+static struct console pti_console = {
+	.name		= TTYNAME,
+	.write		= pti_console_write,
+	.device		= pti_console_device,
+	.setup		= pti_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= 0,
+};
+
+/**
+ * pti_port_activate()- Used to start/initialize any items upon
+ * first opening of tty_port().
+ *
+ * @port- The tty port number of the PTI device.
+ * @tty-  The tty struct associated with this device.
+ *
+ * Returns:
+ *	always returns 0
+ *
+ * Notes: The primary purpose of the PTI tty port 0 is to hook
+ * the syslog daemon to it; thus this port will be open for a
+ * very long time.
+ */
+static int pti_port_activate(struct tty_port *port, struct tty_struct *tty)
+{
+	if (port->tty->index == PTITTY_MINOR_START)
+		console_start(&pti_console);
+	return 0;
+}
+
+/**
+ * pti_port_shutdown()- Used to stop/shutdown any items upon the
+ * last tty port close.
+ *
+ * @port- The tty port number of the PTI device.
+ *
+ * Notes: The primary purpose of the PTI tty port 0 is to hook
+ * the syslog daemon to it; thus this port will be open for a
+ * very long time.
+ */
+static void pti_port_shutdown(struct tty_port *port)
+{
+	if (port->tty->index == PTITTY_MINOR_START)
+		console_stop(&pti_console);
+}
+
+static const struct tty_port_operations tty_port_ops = {
+	.activate = pti_port_activate,
+	.shutdown = pti_port_shutdown,
+};
+
+/*
+ * Note the _probe() call sets everything up and ties the char and tty
+ * to successfully detecting the PTI device on the pci bus.
+ */
+
+/**
+ * pti_pci_probe()- Used to detect pti on the pci bus and set
+ *		    things up in the driver.
+ *
+ * @pdev- pci_dev struct values for pti.
+ * @ent-  pci_device_id struct for pti driver.
+ *
+ * Returns:
+ *	0 for success
+ *	otherwise, error
+ */
+static int __devinit pti_pci_probe(struct pci_dev *pdev,
+		const struct pci_device_id *ent)
+{
+	int retval = -EINVAL;
+	int pci_bar = 1;
+
+	dev_dbg(&pdev->dev, "%s %s(%d): PTI PCI ID %04x:%04x\n", __FILE__,
+			__func__, __LINE__, pdev->vendor, pdev->device);
+
+	retval = misc_register(&pti_char_driver);
+	if (retval) {
+		pr_err("%s(%d): CHAR registration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+		return retval;
+	}
+
+	retval = pci_enable_device(pdev);
+	if (retval != 0) {
+		dev_err(&pdev->dev,
+			"%s: pci_enable_device() returned error %d\n",
+			__func__, retval);
+		return retval;
+	}
+
+	drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
+
+	if (drv_data == NULL) {
+		retval = -ENOMEM;
+		dev_err(&pdev->dev,
+			"%s(%d): kmalloc() returned NULL memory.\n",
+			__func__, __LINE__);
+		return retval;
+	}
+	drv_data->pti_addr = pci_resource_start(pdev, pci_bar);
+
+	retval = pci_request_region(pdev, pci_bar, dev_name(&pdev->dev));
+	if (retval != 0) {
+		dev_err(&pdev->dev,
+			"%s(%d): pci_request_region() returned error %d\n",
+			__func__, __LINE__, retval);
+		kfree(drv_data);
+		return retval;
+	}
+	drv_data->aperture_base = drv_data->pti_addr+APERTURE_14;
+	drv_data->pti_ioaddr =
+		ioremap_nocache((u32)drv_data->aperture_base,
+		APERTURE_LEN);
+	if (!drv_data->pti_ioaddr) {
+		pci_release_region(pdev, pci_bar);
+		retval = -ENOMEM;
+		kfree(drv_data);
+		return retval;
+	}
+
+	pci_set_drvdata(pdev, drv_data);
+
+	tty_port_init(&drv_data->port);
+	drv_data->port.ops = &tty_port_ops;
+
+	tty_register_device(pti_tty_driver, 0, &pdev->dev);
+	tty_register_device(pti_tty_driver, 1, &pdev->dev);
+
+	register_console(&pti_console);
+
+	return retval;
+}
+
+static struct pci_driver pti_pci_driver = {
+	.name		= PCINAME,
+	.id_table	= pci_ids,
+	.probe		= pti_pci_probe,
+	.remove		= pti_pci_remove,
+};
+
+/**
+ *
+ * pti_init()- Overall entry/init call to the pti driver.
+ *             It starts the registration process with the kernel.
+ *
+ * Returns:
+ *	int __init, 0 for success
+ *	otherwise value is an error
+ *
+ */
+static int __init pti_init(void)
+{
+	int retval = -EINVAL;
+
+	/* First register module as tty device */
+
+	pti_tty_driver = alloc_tty_driver(1);
+	if (pti_tty_driver == NULL) {
+		pr_err("%s(%d): Memory allocation failed for ptiTTY driver\n",
+			__func__, __LINE__);
+		return -ENOMEM;
+	}
+
+	pti_tty_driver->owner			= THIS_MODULE;
+	pti_tty_driver->magic			= TTY_DRIVER_MAGIC;
+	pti_tty_driver->driver_name		= DRIVERNAME;
+	pti_tty_driver->name			= TTYNAME;
+	pti_tty_driver->major			= 0;
+	pti_tty_driver->minor_start		= PTITTY_MINOR_START;
+	pti_tty_driver->minor_num		= PTITTY_MINOR_NUM;
+	pti_tty_driver->num			= PTITTY_MINOR_NUM;
+	pti_tty_driver->type			= TTY_DRIVER_TYPE_SYSTEM;
+	pti_tty_driver->subtype			= SYSTEM_TYPE_SYSCONS;
+	pti_tty_driver->flags			= TTY_DRIVER_REAL_RAW |
+						  TTY_DRIVER_DYNAMIC_DEV;
+	pti_tty_driver->init_termios		= tty_std_termios;
+
+	tty_set_operations(pti_tty_driver, &pti_tty_driver_ops);
+
+	retval = tty_register_driver(pti_tty_driver);
+	if (retval) {
+		pr_err("%s(%d): TTY registration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+
+		pti_tty_driver = NULL;
+		return retval;
+	}
+
+	retval = pci_register_driver(&pti_pci_driver);
+
+	if (retval) {
+		pr_err("%s(%d): PCI registration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+
+		tty_unregister_driver(pti_tty_driver);
+		pr_err("%s(%d): Unregistering TTY part of pti driver\n",
+			__func__, __LINE__);
+		pti_tty_driver = NULL;
+		return retval;
+	}
+
+	return retval;
+}
+
+/**
+ * pti_exit()- Unregisters this module as a tty and pci driver.
+ */
+static void __exit pti_exit(void)
+{
+	int retval;
+
+	tty_unregister_device(pti_tty_driver, 0);
+	tty_unregister_device(pti_tty_driver, 1);
+
+	retval = tty_unregister_driver(pti_tty_driver);
+	if (retval) {
+		pr_err("%s(%d): TTY unregistration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+	}
+
+	pci_unregister_driver(&pti_pci_driver);
+
+	retval = misc_deregister(&pti_char_driver);
+	if (retval) {
+		pr_err("%s(%d): CHAR unregistration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+	}
+
+	unregister_console(&pti_console);
+	return;
+}
+
+module_init(pti_init);
+module_exit(pti_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Ken Mills, Jay Freyensee");
+MODULE_DESCRIPTION("PTI Driver");
+
diff --git a/include/linux/pti.h b/include/linux/pti.h
new file mode 100644
index 0000000..81af667
--- /dev/null
+++ b/include/linux/pti.h
@@ -0,0 +1,42 @@
+/*
+ *  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 will allow other parts of the OS to use the
+ * interface to write out it's contents for debugging a mobile system.
+ */
+
+#ifndef PTI_H_
+#define PTI_H_
+
+/* offset for last dword of any PTI message. Part of MIPI P1149.7 */
+#define PTI_LASTDWORD_DTS	0x30
+
+/* basic structure used as a write address to the PTI HW */
+struct pti_masterchannel {
+	u8 master;
+	u8 channel;
+};
+
+/* the following functions are defined in misc/pti.c */
+void pti_writedata(struct pti_masterchannel *mc, u8 *buf, int count);
+struct pti_masterchannel *pti_request_masterchannel(u8 type);
+void pti_release_masterchannel(struct pti_masterchannel *mc);
+
+#endif /*PTI_H_*/
-- 
1.7.2.3