These patches implement a modification of the USBTMC protocol to allow
operation with Rigol equipment. Rigol requires that a single TMC request
to receive any buffer size and bulk requests to get the data. The
original algorithm sends a TMC request for each subset of the data (a
single USB transaction). The modification is only active for Rigol
equipment, vendor and product set is contained in the array usbtmc_id_quirk.
The patches are tested with Rigol equipment but need more validation
with other equipment. The last patch implement an ioctl to dynamically
toggle the algorithm allowing udev to change the behavior without
recompiling the driver.
>From 87c5741be97d98a8f7424d3d35e1dbf758289b7b Mon Sep 17 00:00:00 2001
From: Alexandre Peixoto Ferreira <alexandref75@xxxxxxxxx>
Date: Sun, 14 Apr 2013 20:21:31 -0500
Subject: [PATCH 1/2] Allow usbtmc_read to interface with Rigol version of
USBTMC but preserve the original operating behavior for other equipments
Signed-off-by: Alexandre Peixoto Ferreira <alexandref75@xxxxxxxxx>
---
drivers/usb/class/usbtmc.c | 273 +++++++++++++++++++++++++++++++++------------
1 file changed, 199 insertions(+), 74 deletions(-)
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 70d69d0..e013e7c 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -31,6 +31,8 @@
#include <linux/usb/tmc.h>
+#define RIGOL 1
+#define USBTMC_HEADER_SIZE 12
#define USBTMC_MINOR_BASE 176
/*
@@ -84,6 +86,8 @@ struct usbtmc_device_data {
u8 bTag_last_write; /* needed for abort */
u8 bTag_last_read; /* needed for abort */
+ u8 rigol_quirk;
+
/* attributes from the USB TMC spec for this device */
u8 TermChar;
bool TermCharEnabled;
@@ -97,6 +101,16 @@ struct usbtmc_device_data {
};
#define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
+struct usbtmc_ID_rigol_quirk {
+ __u16 idVendor;
+ __u16 idProduct;
+};
+
+static const struct usbtmc_ID_rigol_quirk usbtmc_id_quirk[] = {
+ { 0x1ab1, 0x0588 },
+ { 0, 0 }
+};
+
/* Forward declarations */
static struct usb_driver usbtmc_driver;
@@ -361,6 +375,59 @@ exit:
return rv;
}
+/*
+ * Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-IN endpoint.
+ * @transfer_size: number of bytes to request from the device.
+ *
+ * See the USBTMC specification, Table 4.
+ *
+ * Also updates bTag_last_write.
+ */
+static int send_request_dev_dep_msg_in(struct usbtmc_device_data *data, size_t transfer_size)
+{
+ int retval;
+ u8 buffer[USBTMC_HEADER_SIZE];
+ int actual;
+
+ /* Setup IO buffer for REQUEST_DEV_DEP_MSG_IN message
+ * Refer to class specs for details
+ */
+ buffer[0] = 2;
+ buffer[1] = data->bTag;
+ buffer[2] = ~(data->bTag);
+ buffer[3] = 0; /* Reserved */
+ buffer[4] = (transfer_size) & 255;
+ buffer[5] = ((transfer_size) >> 8) & 255;
+ buffer[6] = ((transfer_size) >> 16) & 255;
+ buffer[7] = ((transfer_size) >> 24) & 255;
+ buffer[8] = data->TermCharEnabled * 2;
+ /* Use term character? */
+ buffer[9] = data->TermChar;
+ buffer[10] = 0; /* Reserved */
+ buffer[11] = 0; /* Reserved */
+
+ /* Send bulk URB */
+ retval = usb_bulk_msg(data->usb_dev,
+ usb_sndbulkpipe(data->usb_dev,
+ data->bulk_out),
+ buffer, USBTMC_HEADER_SIZE, &actual, USBTMC_TIMEOUT);
+
+ /* Store bTag (in case we need to abort) */
+ data->bTag_last_write = data->bTag;
+
+ /* Increment bTag -- and increment again if zero */
+ data->bTag++;
+ if (!data->bTag)
+ (data->bTag)++;
+
+ if (retval < 0) {
+ dev_err(&data->intf->dev, "usb_bulk_msg in send_request_dev_dep_msg_in() returned %d\n", retval);
+ return retval;
+ }
+
+ return 0;
+}
+
static ssize_t usbtmc_read(struct file *filp, char __user *buf,
size_t count, loff_t *f_pos)
{
@@ -388,52 +455,39 @@ static ssize_t usbtmc_read(struct file *filp, char __user *buf,
goto exit;
}
- remaining = count;
- done = 0;
-
- while (remaining > 0) {
- if (remaining > USBTMC_SIZE_IOBUFFER - 12 - 3)
- this_part = USBTMC_SIZE_IOBUFFER - 12 - 3;
- else
- this_part = remaining;
-
- /* Setup IO buffer for DEV_DEP_MSG_IN message
- * Refer to class specs for details
- */
- buffer[0] = 2;
- buffer[1] = data->bTag;
- buffer[2] = ~(data->bTag);
- buffer[3] = 0; /* Reserved */
- buffer[4] = (this_part) & 255;
- buffer[5] = ((this_part) >> 8) & 255;
- buffer[6] = ((this_part) >> 16) & 255;
- buffer[7] = ((this_part) >> 24) & 255;
- buffer[8] = data->TermCharEnabled * 2;
- /* Use term character? */
- buffer[9] = data->TermChar;
- buffer[10] = 0; /* Reserved */
- buffer[11] = 0; /* Reserved */
-
- /* Send bulk URB */
- retval = usb_bulk_msg(data->usb_dev,
- usb_sndbulkpipe(data->usb_dev,
- data->bulk_out),
- buffer, 12, &actual, USBTMC_TIMEOUT);
-
- /* Store bTag (in case we need to abort) */
- data->bTag_last_write = data->bTag;
+ if (data->rigol_quirk) {
+ dev_dbg(dev, "usb_bulk_msg_in: count(%zu)\n", count);
- /* Increment bTag -- and increment again if zero */
- data->bTag++;
- if (!data->bTag)
- (data->bTag)++;
+ retval = send_request_dev_dep_msg_in(data, count);
if (retval < 0) {
- dev_err(dev, "usb_bulk_msg returned %d\n", retval);
if (data->auto_abort)
usbtmc_ioctl_abort_bulk_out(data);
goto exit;
}
+ }
+
+ /* Loop until we have fetched everything we requested */
+ remaining = count;
+ this_part = remaining;
+ done = 0;
+
+ while (remaining > 0) {
+ if (!(data->rigol_quirk)) {
+ dev_dbg(dev, "usb_bulk_msg_in: remaining(%zu), count(%zu)\n", remaining, count);
+
+ if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3)
+ this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3;
+ else
+ this_part = remaining;
+
+ retval = send_request_dev_dep_msg_in(data, this_part);
+ if (retval < 0) {
+ if (data->auto_abort)
+ usbtmc_ioctl_abort_bulk_out(data);
+ goto exit;
+ }
+ }
/* Send bulk URB */
retval = usb_bulk_msg(data->usb_dev,
@@ -442,51 +496,108 @@ static ssize_t usbtmc_read(struct file *filp, char __user *buf,
buffer, USBTMC_SIZE_IOBUFFER, &actual,
USBTMC_TIMEOUT);
+ dev_dbg(dev, "usb_bulk_msg: retval(%u), done(%zu), remaining(%zu), actual(%d)\n", retval, done, remaining, actual);
+
/* Store bTag (in case we need to abort) */
data->bTag_last_read = data->bTag;
if (retval < 0) {
- dev_err(dev, "Unable to read data, error %d\n", retval);
+ dev_dbg(dev, "Unable to read data, error %d\n", retval);
if (data->auto_abort)
usbtmc_ioctl_abort_bulk_in(data);
goto exit;
}
- /* How many characters did the instrument send? */
- n_characters = buffer[4] +
- (buffer[5] << 8) +
- (buffer[6] << 16) +
- (buffer[7] << 24);
+ /* Parse header in first packet */
+ if ((done == 0) || (!(data->rigol_quirk))) {
+ /* Sanity checks for the header */
+ if (actual < USBTMC_HEADER_SIZE) {
+ dev_err(dev, "Device sent too small first packet: %u < %u\n", actual, USBTMC_HEADER_SIZE);
+ if (data->auto_abort)
+ usbtmc_ioctl_abort_bulk_in(data);
+ goto exit;
+ }
- /* Ensure the instrument doesn't lie about it */
- if(n_characters > actual - 12) {
- dev_err(dev, "Device lies about message size: %u > %d\n", n_characters, actual - 12);
- n_characters = actual - 12;
- }
+ if (buffer[0] != 2) {
+ dev_err(dev, "Device sent reply with wrong MsgID: %u != 2\n", buffer[0]);
+ if (data->auto_abort)
+ usbtmc_ioctl_abort_bulk_in(data);
+ goto exit;
+ }
- /* Ensure the instrument doesn't send more back than requested */
- if(n_characters > this_part) {
- dev_err(dev, "Device returns more than requested: %zu > %zu\n", done + n_characters, done + this_part);
- n_characters = this_part;
- }
+ if (buffer[1] != data->bTag_last_write) {
+ dev_err(dev, "Device sent reply with wrong bTag: %u != %u\n", buffer[1], data->bTag_last_write);
+ if (data->auto_abort)
+ usbtmc_ioctl_abort_bulk_in(data);
+ goto exit;
+ }
- /* Bound amount of data received by amount of data requested */
- if (n_characters > this_part)
- n_characters = this_part;
+ n_characters = buffer[4] +
+ (buffer[5] << 8) +
+ (buffer[6] << 16) +
+ (buffer[7] << 24);
- /* Copy buffer to user space */
- if (copy_to_user(buf + done, &buffer[12], n_characters)) {
- /* There must have been an addressing problem */
- retval = -EFAULT;
- goto exit;
+ if (n_characters > this_part) {
+ dev_err(dev, "Device wants to return more data than requested: %u > %zu\n", n_characters, count);
+ if (data->auto_abort)
+ usbtmc_ioctl_abort_bulk_in(data);
+ goto exit;
+ }
+
+ /* Remove the USBTMC header */
+ actual -= USBTMC_HEADER_SIZE;
+
+ /* Check if the message is smaller than requested */
+ if (data->rigol_quirk) {
+ if (remaining > n_characters)
+ remaining = n_characters;
+ /* Remove padding if it exists */
+ if (actual > remaining)
+ actual = remaining;
+ }
+ else {
+ if (this_part > n_characters)
+ this_part = n_characters;
+ /* Remove padding if it exists */
+ if (actual > this_part)
+ actual = this_part;
+ }
+
+ dev_dbg(dev, "Bulk-IN header: N_characters(%u), bTransAttr(%u)\n", n_characters, buffer[8]);
+
+ remaining -= actual;
+
+ /* Terminate if end-of-message bit received from device */
+ if ((buffer[8] & 0x01) && (actual >= n_characters))
+ remaining = 0;
+
+ dev_dbg(dev, "Bulk-IN header: remaining(%zu), buf(%p), buffer(%p) done(%zu)\n", remaining,buf,buffer,done);
+
+
+ /* Copy buffer to user space */
+ if (copy_to_user(buf + done, &buffer[USBTMC_HEADER_SIZE], actual)) {
+ /* There must have been an addressing problem */
+ retval = -EFAULT;
+ goto exit;
+ }
+ done += actual;
}
+ else {
+ if (actual > remaining)
+ actual = remaining;
+
+ remaining -= actual;
+
+ dev_dbg(dev, "Bulk-IN header cont: actual(%u), done(%zu), remaining(%zu), buf(%p), buffer(%p)\n", actual, done, remaining,buf,buffer);
- done += n_characters;
- /* Terminate if end-of-message bit received from device */
- if ((buffer[8] & 0x01) && (actual >= n_characters + 12))
- remaining = 0;
- else
- remaining -= n_characters;
+ /* Copy buffer to user space */
+ if (copy_to_user(buf + done, buffer, actual)) {
+ /* There must have been an addressing problem */
+ retval = -EFAULT;
+ goto exit;
+ }
+ done += actual;
+ }
}
/* Update file position value */
@@ -527,8 +638,8 @@ static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
done = 0;
while (remaining > 0) {
- if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
- this_part = USBTMC_SIZE_IOBUFFER - 12;
+ if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE) {
+ this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE;
buffer[8] = 0;
} else {
this_part = remaining;
@@ -549,13 +660,13 @@ static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
buffer[10] = 0; /* Reserved */
buffer[11] = 0; /* Reserved */
- if (copy_from_user(&buffer[12], buf + done, this_part)) {
+ if (copy_from_user(&buffer[USBTMC_HEADER_SIZE], buf + done, this_part)) {
retval = -EFAULT;
goto exit;
}
- n_bytes = roundup(12 + this_part, 4);
- memset(buffer + 12 + this_part, 0, n_bytes - (12 + this_part));
+ n_bytes = roundup(USBTMC_HEADER_SIZE + this_part, 4);
+ memset(buffer + USBTMC_HEADER_SIZE + this_part, 0, n_bytes - (USBTMC_HEADER_SIZE + this_part));
do {
retval = usb_bulk_msg(data->usb_dev,
@@ -1021,6 +1132,20 @@ static int usbtmc_probe(struct usb_interface *intf,
mutex_init(&data->io_mutex);
data->zombie = 0;
+ /* Determine if it is a Rigol or not */
+ data->rigol_quirk = 0;
+ dev_dbg(&intf->dev, "Trying to find if device Vendor 0x%04X Product 0x%04X has the RIGOL quirk\n",
+ data->usb_dev->descriptor.idVendor,
+ data->usb_dev->descriptor.idProduct);
+ for(n = 0; usbtmc_id_quirk[n].idVendor > 0; n++) {
+ if ((usbtmc_id_quirk[n].idVendor == data->usb_dev->descriptor.idVendor) &&
+ (usbtmc_id_quirk[n].idProduct == data->usb_dev->descriptor.idProduct)) {
+ dev_dbg(&intf->dev, "Setting this device as having the RIGOL quirk\n");
+ data->rigol_quirk = 1;
+ break;
+ }
+ }
+
/* Initialize USBTMC bTag and other fields */
data->bTag = 1;
data->TermCharEnabled = 0;
--
1.8.2.1
>From ed1e6f9426bd289775e0d4a7c700c6a13318364d Mon Sep 17 00:00:00 2001
From: Alexandre Peixoto Ferreira <alexandref75@xxxxxxxxx>
Date: Sun, 14 Apr 2013 20:24:15 -0500
Subject: [PATCH 2/2] Add IOCTL otion in USBTMC to change from Rigol mode to
traditional and vice-versa
Signed-off-by: Alexandre Peixoto Ferreira <alexandref75@xxxxxxxxx>
---
drivers/usb/class/usbtmc.c | 25 +++++++++++++++++++++++++
include/uapi/linux/usb/tmc.h | 1 +
2 files changed, 26 insertions(+)
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index e013e7c..c7ace5f 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -154,6 +154,28 @@ static int usbtmc_release(struct inode *inode, struct file *file)
return 0;
}
+static int usbtmc_ioctl_rigol_quirk(struct usbtmc_device_data *data,unsigned long arg)
+{
+ struct device *dev;
+
+ dev = &data->intf->dev;
+
+ switch(arg) {
+ case 0 : /* RESET RIGOL QUIRK MODE IF SET */
+ data->rigol_quirk = 0;
+ return 0;
+ case 1 : /* RESET RIGOL QUIRK MODE IF SET */
+ data->rigol_quirk = 1;
+ return 0;
+ case 2 : /* Check it it is set */
+ if (data->rigol_quirk)
+ return 0;
+ else
+ return -EINVAL;
+ }
+ return 0;
+}
+
static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
{
u8 *buffer;
@@ -1083,6 +1105,9 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case USBTMC_IOCTL_ABORT_BULK_IN:
retval = usbtmc_ioctl_abort_bulk_in(data);
break;
+ case USBTMC_IOCTL_RIGOL_QUIRK:
+ retval = usbtmc_ioctl_rigol_quirk(data,arg);
+ break;
}
skip_io_on_zombie:
diff --git a/include/uapi/linux/usb/tmc.h b/include/uapi/linux/usb/tmc.h
index c045ae1..1787460 100644
--- a/include/uapi/linux/usb/tmc.h
+++ b/include/uapi/linux/usb/tmc.h
@@ -39,5 +39,6 @@
#define USBTMC_IOCTL_ABORT_BULK_IN _IO(USBTMC_IOC_NR, 4)
#define USBTMC_IOCTL_CLEAR_OUT_HALT _IO(USBTMC_IOC_NR, 6)
#define USBTMC_IOCTL_CLEAR_IN_HALT _IO(USBTMC_IOC_NR, 7)
+#define USBTMC_IOCTL_RIGOL_QUIRK _IO(USBTMC_IOC_NR, 8)
#endif
--
1.8.2.1
