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authorJacob Feder <jacobsfeder@gmail.com>2018-07-22 21:27:37 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-07-24 14:14:13 +0200
commit4a965c5f89decd636129cddc47e5f2c61e8f13e6 (patch)
tree865033e3702811c95989d03adbe89bfd831cf093 /drivers
parent670c6365c91e345582bf905e946ed35fb684891e (diff)
staging: add driver for Xilinx AXI-Stream FIFO v4.1 IP core
This IP core has read and write AXI-Stream FIFOs, the contents of which can be accessed from the AXI4 memory-mapped interface. This is useful for transferring data from a processor into the FPGA fabric. The driver creates a character device that can be read/written to with standard open/read/write/close. See Xilinx PG080 document for IP details. https://www.xilinx.com/support/documentation/ip_documentation/axi_fifo_mm_s/v4_1/pg080-axi-fifo-mm-s.pdf The driver currently supports only store-forward mode with a 32-bit AXI4 Lite interface. DOES NOT support: - cut-through mode - AXI4 (non-lite) Signed-off-by: Jacob Feder <jacobsfeder@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/staging/Kconfig2
-rw-r--r--drivers/staging/Makefile1
-rw-r--r--drivers/staging/axis-fifo/Kconfig9
-rw-r--r--drivers/staging/axis-fifo/Makefile1
-rw-r--r--drivers/staging/axis-fifo/README0
-rw-r--r--drivers/staging/axis-fifo/axis-fifo.c1108
-rw-r--r--drivers/staging/axis-fifo/axis-fifo.txt89
7 files changed, 1210 insertions, 0 deletions
diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index 3fa39109bd75..17fd9b455ec6 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -124,4 +124,6 @@ source "drivers/staging/mt7621-dts/Kconfig"
source "drivers/staging/gasket/Kconfig"
+source "drivers/staging/axis-fifo/Kconfig"
+
endif # STAGING
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index 7a0ff10f5ebb..231698f2da7d 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -53,3 +53,4 @@ obj-$(CONFIG_SOC_MT7621) += mt7621-mmc/
obj-$(CONFIG_SOC_MT7621) += mt7621-eth/
obj-$(CONFIG_SOC_MT7621) += mt7621-dts/
obj-$(CONFIG_STAGING_GASKET_FRAMEWORK) += gasket/
+obj-$(CONFIG_XIL_AXIS_FIFO) += axis-fifo/
diff --git a/drivers/staging/axis-fifo/Kconfig b/drivers/staging/axis-fifo/Kconfig
new file mode 100644
index 000000000000..687537203d9c
--- /dev/null
+++ b/drivers/staging/axis-fifo/Kconfig
@@ -0,0 +1,9 @@
+#
+# "Xilinx AXI-Stream FIFO IP core driver"
+#
+config XIL_AXIS_FIFO
+ tristate "Xilinx AXI-Stream FIFO IP core driver"
+ default n
+ help
+ This adds support for the Xilinx AXI-Stream
+ FIFO IP core driver.
diff --git a/drivers/staging/axis-fifo/Makefile b/drivers/staging/axis-fifo/Makefile
new file mode 100644
index 000000000000..fe62cd1ac5de
--- /dev/null
+++ b/drivers/staging/axis-fifo/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_XIL_AXIS_FIFO) += axis-fifo.o
diff --git a/drivers/staging/axis-fifo/README b/drivers/staging/axis-fifo/README
new file mode 100644
index 000000000000..e69de29bb2d1
--- /dev/null
+++ b/drivers/staging/axis-fifo/README
diff --git a/drivers/staging/axis-fifo/axis-fifo.c b/drivers/staging/axis-fifo/axis-fifo.c
new file mode 100644
index 000000000000..2a73302620ec
--- /dev/null
+++ b/drivers/staging/axis-fifo/axis-fifo.c
@@ -0,0 +1,1108 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx AXIS FIFO: interface to the Xilinx AXI-Stream FIFO IP core
+ *
+ * Copyright (C) 2018 Jacob Feder
+ *
+ * Authors: Jacob Feder <jacobsfeder@gmail.com>
+ *
+ * See Xilinx PG080 document for IP details
+ */
+
+/* ----------------------------
+ * includes
+ * ----------------------------
+ */
+
+#include <linux/kernel.h>
+#include <linux/wait.h>
+#include <linux/spinlock_types.h>
+#include <linux/device.h>
+#include <linux/cdev.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/moduleparam.h>
+#include <linux/interrupt.h>
+#include <linux/param.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/cdev.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/jiffies.h>
+
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+
+/* ----------------------------
+ * driver parameters
+ * ----------------------------
+ */
+
+#define DRIVER_NAME "axis_fifo"
+
+#define READ_BUF_SIZE 128U /* read buffer length in words */
+#define WRITE_BUF_SIZE 128U /* write buffer length in words */
+
+/* ----------------------------
+ * IP register offsets
+ * ----------------------------
+ */
+
+#define XLLF_ISR_OFFSET 0x00000000 /* Interrupt Status */
+#define XLLF_IER_OFFSET 0x00000004 /* Interrupt Enable */
+
+#define XLLF_TDFR_OFFSET 0x00000008 /* Transmit Reset */
+#define XLLF_TDFV_OFFSET 0x0000000c /* Transmit Vacancy */
+#define XLLF_TDFD_OFFSET 0x00000010 /* Transmit Data */
+#define XLLF_TLR_OFFSET 0x00000014 /* Transmit Length */
+
+#define XLLF_RDFR_OFFSET 0x00000018 /* Receive Reset */
+#define XLLF_RDFO_OFFSET 0x0000001c /* Receive Occupancy */
+#define XLLF_RDFD_OFFSET 0x00000020 /* Receive Data */
+#define XLLF_RLR_OFFSET 0x00000024 /* Receive Length */
+#define XLLF_SRR_OFFSET 0x00000028 /* Local Link Reset */
+#define XLLF_TDR_OFFSET 0x0000002C /* Transmit Destination */
+#define XLLF_RDR_OFFSET 0x00000030 /* Receive Destination */
+
+/* ----------------------------
+ * reset register masks
+ * ----------------------------
+ */
+
+#define XLLF_RDFR_RESET_MASK 0x000000a5 /* receive reset value */
+#define XLLF_TDFR_RESET_MASK 0x000000a5 /* Transmit reset value */
+#define XLLF_SRR_RESET_MASK 0x000000a5 /* Local Link reset value */
+
+/* ----------------------------
+ * interrupt masks
+ * ----------------------------
+ */
+
+#define XLLF_INT_RPURE_MASK 0x80000000 /* Receive under-read */
+#define XLLF_INT_RPORE_MASK 0x40000000 /* Receive over-read */
+#define XLLF_INT_RPUE_MASK 0x20000000 /* Receive underrun (empty) */
+#define XLLF_INT_TPOE_MASK 0x10000000 /* Transmit overrun */
+#define XLLF_INT_TC_MASK 0x08000000 /* Transmit complete */
+#define XLLF_INT_RC_MASK 0x04000000 /* Receive complete */
+#define XLLF_INT_TSE_MASK 0x02000000 /* Transmit length mismatch */
+#define XLLF_INT_TRC_MASK 0x01000000 /* Transmit reset complete */
+#define XLLF_INT_RRC_MASK 0x00800000 /* Receive reset complete */
+#define XLLF_INT_TFPF_MASK 0x00400000 /* Tx FIFO Programmable Full */
+#define XLLF_INT_TFPE_MASK 0x00200000 /* Tx FIFO Programmable Empty */
+#define XLLF_INT_RFPF_MASK 0x00100000 /* Rx FIFO Programmable Full */
+#define XLLF_INT_RFPE_MASK 0x00080000 /* Rx FIFO Programmable Empty */
+#define XLLF_INT_ALL_MASK 0xfff80000 /* All the ints */
+#define XLLF_INT_ERROR_MASK 0xf2000000 /* Error status ints */
+#define XLLF_INT_RXERROR_MASK 0xe0000000 /* Receive Error status ints */
+#define XLLF_INT_TXERROR_MASK 0x12000000 /* Transmit Error status ints */
+
+/* ----------------------------
+ * globals
+ * ----------------------------
+ */
+
+static struct class *axis_fifo_driver_class; /* char device class */
+
+static int read_timeout = 1000; /* ms to wait before read() times out */
+static int write_timeout = 1000; /* ms to wait before write() times out */
+
+/* ----------------------------
+ * module command-line arguments
+ * ----------------------------
+ */
+
+module_param(read_timeout, int, 0444);
+MODULE_PARM_DESC(read_timeout, "ms to wait before blocking read() timing out; set to -1 for no timeout");
+module_param(write_timeout, int, 0444);
+MODULE_PARM_DESC(write_timeout, "ms to wait before blocking write() timing out; set to -1 for no timeout");
+
+/* ----------------------------
+ * types
+ * ----------------------------
+ */
+
+struct axis_fifo {
+ int irq; /* interrupt */
+ struct resource *mem; /* physical memory */
+ void __iomem *base_addr; /* kernel space memory */
+
+ unsigned int rx_fifo_depth; /* max words in the receive fifo */
+ unsigned int tx_fifo_depth; /* max words in the transmit fifo */
+ int has_rx_fifo; /* whether the IP has the rx fifo enabled */
+ int has_tx_fifo; /* whether the IP has the tx fifo enabled */
+
+ wait_queue_head_t read_queue; /* wait queue for asynchronos read */
+ spinlock_t read_queue_lock; /* lock for reading waitqueue */
+ wait_queue_head_t write_queue; /* wait queue for asynchronos write */
+ spinlock_t write_queue_lock; /* lock for writing waitqueue */
+ unsigned int write_flags; /* write file flags */
+ unsigned int read_flags; /* read file flags */
+
+ struct device *dt_device; /* device created from the device tree */
+ struct device *device; /* device associated with char_device */
+ dev_t devt; /* our char device number */
+ struct cdev char_device; /* our char device */
+};
+
+/* ----------------------------
+ * sysfs entries
+ * ----------------------------
+ */
+
+static ssize_t sysfs_write(struct device *dev, const char *buf,
+ size_t count, unsigned int addr_offset)
+{
+ struct axis_fifo *fifo = dev_get_drvdata(dev);
+ unsigned long tmp;
+ int rc;
+
+ rc = kstrtoul(buf, 0, &tmp);
+ if (rc < 0)
+ return rc;
+
+ iowrite32(tmp, fifo->base_addr + addr_offset);
+
+ return count;
+}
+
+static ssize_t sysfs_read(struct device *dev, char *buf,
+ unsigned int addr_offset)
+{
+ struct axis_fifo *fifo = dev_get_drvdata(dev);
+ unsigned int read_val;
+ unsigned int len;
+ char tmp[32];
+
+ read_val = ioread32(fifo->base_addr + addr_offset);
+ len = snprintf(tmp, sizeof(tmp), "0x%x\n", read_val);
+ memcpy(buf, tmp, len);
+
+ return len;
+}
+
+static ssize_t isr_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return sysfs_write(dev, buf, count, XLLF_ISR_OFFSET);
+}
+
+static ssize_t isr_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sysfs_read(dev, buf, XLLF_ISR_OFFSET);
+}
+
+static DEVICE_ATTR_RW(isr);
+
+static ssize_t ier_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return sysfs_write(dev, buf, count, XLLF_IER_OFFSET);
+}
+
+static ssize_t ier_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sysfs_read(dev, buf, XLLF_IER_OFFSET);
+}
+
+static DEVICE_ATTR_RW(ier);
+
+static ssize_t tdfr_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return sysfs_write(dev, buf, count, XLLF_TDFR_OFFSET);
+}
+
+static DEVICE_ATTR_WO(tdfr);
+
+static ssize_t tdfv_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sysfs_read(dev, buf, XLLF_TDFV_OFFSET);
+}
+
+static DEVICE_ATTR_RO(tdfv);
+
+static ssize_t tdfd_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return sysfs_write(dev, buf, count, XLLF_TDFD_OFFSET);
+}
+
+static DEVICE_ATTR_WO(tdfd);
+
+static ssize_t tlr_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return sysfs_write(dev, buf, count, XLLF_TLR_OFFSET);
+}
+
+static DEVICE_ATTR_WO(tlr);
+
+static ssize_t rdfr_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return sysfs_write(dev, buf, count, XLLF_RDFR_OFFSET);
+}
+
+static DEVICE_ATTR_WO(rdfr);
+
+static ssize_t rdfo_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sysfs_read(dev, buf, XLLF_RDFO_OFFSET);
+}
+
+static DEVICE_ATTR_RO(rdfo);
+
+static ssize_t rdfd_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sysfs_read(dev, buf, XLLF_RDFD_OFFSET);
+}
+
+static DEVICE_ATTR_RO(rdfd);
+
+static ssize_t rlr_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sysfs_read(dev, buf, XLLF_RLR_OFFSET);
+}
+
+static DEVICE_ATTR_RO(rlr);
+
+static ssize_t srr_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return sysfs_write(dev, buf, count, XLLF_SRR_OFFSET);
+}
+
+static DEVICE_ATTR_WO(srr);
+
+static ssize_t tdr_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return sysfs_write(dev, buf, count, XLLF_TDR_OFFSET);
+}
+
+static DEVICE_ATTR_WO(tdr);
+
+static ssize_t rdr_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sysfs_read(dev, buf, XLLF_RDR_OFFSET);
+}
+
+static DEVICE_ATTR_RO(rdr);
+
+static struct attribute *axis_fifo_attrs[] = {
+ &dev_attr_isr.attr,
+ &dev_attr_ier.attr,
+ &dev_attr_tdfr.attr,
+ &dev_attr_tdfv.attr,
+ &dev_attr_tdfd.attr,
+ &dev_attr_tlr.attr,
+ &dev_attr_rdfr.attr,
+ &dev_attr_rdfo.attr,
+ &dev_attr_rdfd.attr,
+ &dev_attr_rlr.attr,
+ &dev_attr_srr.attr,
+ &dev_attr_tdr.attr,
+ &dev_attr_rdr.attr,
+ NULL,
+};
+
+static const struct attribute_group axis_fifo_attrs_group = {
+ .name = "ip_registers",
+ .attrs = axis_fifo_attrs,
+};
+
+/* ----------------------------
+ * implementation
+ * ----------------------------
+ */
+
+static void reset_ip_core(struct axis_fifo *fifo)
+{
+ iowrite32(XLLF_SRR_RESET_MASK, fifo->base_addr + XLLF_SRR_OFFSET);
+ iowrite32(XLLF_TDFR_RESET_MASK, fifo->base_addr + XLLF_TDFR_OFFSET);
+ iowrite32(XLLF_RDFR_RESET_MASK, fifo->base_addr + XLLF_RDFR_OFFSET);
+ iowrite32(XLLF_INT_TC_MASK | XLLF_INT_RC_MASK | XLLF_INT_RPURE_MASK |
+ XLLF_INT_RPORE_MASK | XLLF_INT_RPUE_MASK |
+ XLLF_INT_TPOE_MASK | XLLF_INT_TSE_MASK,
+ fifo->base_addr + XLLF_IER_OFFSET);
+ iowrite32(XLLF_INT_ALL_MASK, fifo->base_addr + XLLF_ISR_OFFSET);
+}
+
+/* reads a single packet from the fifo as dictated by the tlast signal */
+static ssize_t axis_fifo_read(struct file *f, char __user *buf,
+ size_t len, loff_t *off)
+{
+ struct axis_fifo *fifo = (struct axis_fifo *)f->private_data;
+ size_t bytes_available;
+ unsigned int words_available;
+ unsigned int copied;
+ unsigned int copy;
+ unsigned int i;
+ int ret;
+ u32 tmp_buf[READ_BUF_SIZE];
+
+ if (fifo->read_flags & O_NONBLOCK) {
+ /* opened in non-blocking mode
+ * return if there are no packets available
+ */
+ if (!ioread32(fifo->base_addr + XLLF_RDFO_OFFSET))
+ return -EAGAIN;
+ } else {
+ /* opened in blocking mode
+ * wait for a packet available interrupt (or timeout)
+ * if nothing is currently available
+ */
+ spin_lock_irq(&fifo->read_queue_lock);
+ ret = wait_event_interruptible_lock_irq_timeout(
+ fifo->read_queue,
+ ioread32(fifo->base_addr + XLLF_RDFO_OFFSET),
+ fifo->read_queue_lock,
+ (read_timeout >= 0) ? msecs_to_jiffies(read_timeout) :
+ MAX_SCHEDULE_TIMEOUT);
+ spin_unlock_irq(&fifo->read_queue_lock);
+
+ if (ret == 0) {
+ /* timeout occurred */
+ dev_dbg(fifo->dt_device, "read timeout");
+ return -EAGAIN;
+ } else if (ret == -ERESTARTSYS) {
+ /* signal received */
+ return -ERESTARTSYS;
+ } else if (ret < 0) {
+ dev_err(fifo->dt_device, "wait_event_interruptible_timeout() error in read (ret=%i)\n",
+ ret);
+ return ret;
+ }
+ }
+
+ bytes_available = ioread32(fifo->base_addr + XLLF_RLR_OFFSET);
+ if (!bytes_available) {
+ dev_err(fifo->dt_device, "received a packet of length 0 - fifo core will be reset\n");
+ reset_ip_core(fifo);
+ return -EIO;
+ }
+
+ if (bytes_available > len) {
+ dev_err(fifo->dt_device, "user read buffer too small (available bytes=%zu user buffer bytes=%zu) - fifo core will be reset\n",
+ bytes_available, len);
+ reset_ip_core(fifo);
+ return -EINVAL;
+ }
+
+ if (bytes_available % sizeof(u32)) {
+ /* this probably can't happen unless IP
+ * registers were previously mishandled
+ */
+ dev_err(fifo->dt_device, "received a packet that isn't word-aligned - fifo core will be reset\n");
+ reset_ip_core(fifo);
+ return -EIO;
+ }
+
+ words_available = bytes_available / sizeof(u32);
+
+ /* read data into an intermediate buffer, copying the contents
+ * to userspace when the buffer is full
+ */
+ copied = 0;
+ while (words_available > 0) {
+ copy = min(words_available, READ_BUF_SIZE);
+
+ for (i = 0; i < copy; i++) {
+ tmp_buf[i] = ioread32(fifo->base_addr +
+ XLLF_RDFD_OFFSET);
+ }
+
+ if (copy_to_user(buf + copied * sizeof(u32), tmp_buf,
+ copy * sizeof(u32))) {
+ reset_ip_core(fifo);
+ return -EFAULT;
+ }
+
+ copied += copy;
+ words_available -= copy;
+ }
+
+ return bytes_available;
+}
+
+static ssize_t axis_fifo_write(struct file *f, const char __user *buf,
+ size_t len, loff_t *off)
+{
+ struct axis_fifo *fifo = (struct axis_fifo *)f->private_data;
+ unsigned int words_to_write;
+ unsigned int copied;
+ unsigned int copy;
+ unsigned int i;
+ int ret;
+ u32 tmp_buf[WRITE_BUF_SIZE];
+
+ if (len % sizeof(u32)) {
+ dev_err(fifo->dt_device,
+ "tried to send a packet that isn't word-aligned\n");
+ return -EINVAL;
+ }
+
+ words_to_write = len / sizeof(u32);
+
+ if (!words_to_write) {
+ dev_err(fifo->dt_device,
+ "tried to send a packet of length 0\n");
+ return -EINVAL;
+ }
+
+ if (words_to_write > fifo->tx_fifo_depth) {
+ dev_err(fifo->dt_device, "tried to write more words [%u] than slots in the fifo buffer [%u]\n",
+ words_to_write, fifo->tx_fifo_depth);
+ return -EINVAL;
+ }
+
+ if (fifo->write_flags & O_NONBLOCK) {
+ /* opened in non-blocking mode
+ * return if there is not enough room available in the fifo
+ */
+ if (words_to_write > ioread32(fifo->base_addr +
+ XLLF_TDFV_OFFSET)) {
+ return -EAGAIN;
+ }
+ } else {
+ /* opened in blocking mode */
+
+ /* wait for an interrupt (or timeout) if there isn't
+ * currently enough room in the fifo
+ */
+ spin_lock_irq(&fifo->write_queue_lock);
+ ret = wait_event_interruptible_lock_irq_timeout(
+ fifo->write_queue,
+ ioread32(fifo->base_addr + XLLF_TDFV_OFFSET)
+ >= words_to_write,
+ fifo->write_queue_lock,
+ (write_timeout >= 0) ? msecs_to_jiffies(write_timeout) :
+ MAX_SCHEDULE_TIMEOUT);
+ spin_unlock_irq(&fifo->write_queue_lock);
+
+ if (ret == 0) {
+ /* timeout occurred */
+ dev_dbg(fifo->dt_device, "write timeout\n");
+ return -EAGAIN;
+ } else if (ret == -ERESTARTSYS) {
+ /* signal received */
+ return -ERESTARTSYS;
+ } else if (ret < 0) {
+ /* unknown error */
+ dev_err(fifo->dt_device,
+ "wait_event_interruptible_timeout() error in write (ret=%i)\n",
+ ret);
+ return ret;
+ }
+ }
+
+ /* write data from an intermediate buffer into the fifo IP, refilling
+ * the buffer with userspace data as needed
+ */
+ copied = 0;
+ while (words_to_write > 0) {
+ copy = min(words_to_write, WRITE_BUF_SIZE);
+
+ if (copy_from_user(tmp_buf, buf + copied * sizeof(u32),
+ copy * sizeof(u32))) {
+ reset_ip_core(fifo);
+ return -EFAULT;
+ }
+
+ for (i = 0; i < copy; i++)
+ iowrite32(tmp_buf[i], fifo->base_addr +
+ XLLF_TDFD_OFFSET);
+
+ copied += copy;
+ words_to_write -= copy;
+ }
+
+ /* write packet size to fifo */
+ iowrite32(copied * sizeof(u32), fifo->base_addr + XLLF_TLR_OFFSET);
+
+ return (ssize_t)copied * sizeof(u32);
+}
+
+static irqreturn_t axis_fifo_irq(int irq, void *dw)
+{
+ struct axis_fifo *fifo = (struct axis_fifo *)dw;
+ unsigned int pending_interrupts;
+
+ do {
+ pending_interrupts = ioread32(fifo->base_addr +
+ XLLF_IER_OFFSET) &
+ ioread32(fifo->base_addr
+ + XLLF_ISR_OFFSET);
+ if (pending_interrupts & XLLF_INT_RC_MASK) {
+ /* packet received */
+
+ /* wake the reader process if it is waiting */
+ wake_up(&fifo->read_queue);
+
+ /* clear interrupt */
+ iowrite32(XLLF_INT_RC_MASK & XLLF_INT_ALL_MASK,
+ fifo->base_addr + XLLF_ISR_OFFSET);
+ } else if (pending_interrupts & XLLF_INT_TC_MASK) {
+ /* packet sent */
+
+ /* wake the writer process if it is waiting */
+ wake_up(&fifo->write_queue);
+
+ iowrite32(XLLF_INT_TC_MASK & XLLF_INT_ALL_MASK,
+ fifo->base_addr + XLLF_ISR_OFFSET);
+ } else if (pending_interrupts & XLLF_INT_TFPF_MASK) {
+ /* transmit fifo programmable full */
+
+ iowrite32(XLLF_INT_TFPF_MASK & XLLF_INT_ALL_MASK,
+ fifo->base_addr + XLLF_ISR_OFFSET);
+ } else if (pending_interrupts & XLLF_INT_TFPE_MASK) {
+ /* transmit fifo programmable empty */
+
+ iowrite32(XLLF_INT_TFPE_MASK & XLLF_INT_ALL_MASK,
+ fifo->base_addr + XLLF_ISR_OFFSET);
+ } else if (pending_interrupts & XLLF_INT_RFPF_MASK) {
+ /* receive fifo programmable full */
+
+ iowrite32(XLLF_INT_RFPF_MASK & XLLF_INT_ALL_MASK,
+ fifo->base_addr + XLLF_ISR_OFFSET);
+ } else if (pending_interrupts & XLLF_INT_RFPE_MASK) {
+ /* receive fifo programmable empty */
+
+ iowrite32(XLLF_INT_RFPE_MASK & XLLF_INT_ALL_MASK,
+ fifo->base_addr + XLLF_ISR_OFFSET);
+ } else if (pending_interrupts & XLLF_INT_TRC_MASK) {
+ /* transmit reset complete interrupt */
+
+ iowrite32(XLLF_INT_TRC_MASK & XLLF_INT_ALL_MASK,
+ fifo->base_addr + XLLF_ISR_OFFSET);
+ } else if (pending_interrupts & XLLF_INT_RRC_MASK) {
+ /* receive reset complete interrupt */
+
+ iowrite32(XLLF_INT_RRC_MASK & XLLF_INT_ALL_MASK,
+ fifo->base_addr + XLLF_ISR_OFFSET);
+ } else if (pending_interrupts & XLLF_INT_RPURE_MASK) {
+ /* receive fifo under-read error interrupt */
+ dev_err(fifo->dt_device,
+ "receive under-read interrupt\n");
+
+ iowrite32(XLLF_INT_RPURE_MASK & XLLF_INT_ALL_MASK,
+ fifo->base_addr + XLLF_ISR_OFFSET);
+ } else if (pending_interrupts & XLLF_INT_RPORE_MASK) {
+ /* receive over-read error interrupt */
+ dev_err(fifo->dt_device,
+ "receive over-read interrupt\n");
+
+ iowrite32(XLLF_INT_RPORE_MASK & XLLF_INT_ALL_MASK,
+ fifo->base_addr + XLLF_ISR_OFFSET);
+ } else if (pending_interrupts & XLLF_INT_RPUE_MASK) {
+ /* receive underrun error interrupt */
+ dev_err(fifo->dt_device,
+ "receive underrun error interrupt\n");
+
+ iowrite32(XLLF_INT_RPUE_MASK & XLLF_INT_ALL_MASK,
+ fifo->base_addr + XLLF_ISR_OFFSET);
+ } else if (pending_interrupts & XLLF_INT_TPOE_MASK) {
+ /* transmit overrun error interrupt */
+ dev_err(fifo->dt_device,
+ "transmit overrun error interrupt\n");
+
+ iowrite32(XLLF_INT_TPOE_MASK & XLLF_INT_ALL_MASK,
+ fifo->base_addr + XLLF_ISR_OFFSET);
+ } else if (pending_interrupts & XLLF_INT_TSE_MASK) {
+ /* transmit length mismatch error interrupt */
+ dev_err(fifo->dt_device,
+ "transmit length mismatch error interrupt\n");
+
+ iowrite32(XLLF_INT_TSE_MASK & XLLF_INT_ALL_MASK,
+ fifo->base_addr + XLLF_ISR_OFFSET);
+ } else if (pending_interrupts) {
+ /* unknown interrupt type */
+ dev_err(fifo->dt_device,
+ "unknown interrupt(s) 0x%x\n",
+ pending_interrupts);
+
+ iowrite32(XLLF_INT_ALL_MASK,
+ fifo->base_addr + XLLF_ISR_OFFSET);
+ }
+ } while (pending_interrupts);
+
+ return IRQ_HANDLED;
+}
+
+static int axis_fifo_open(struct inode *inod, struct file *f)
+{
+ struct axis_fifo *fifo = (struct axis_fifo *)container_of(inod->i_cdev,
+ struct axis_fifo, char_device);
+ f->private_data = fifo;
+
+ if (((f->f_flags & O_ACCMODE) == O_WRONLY) ||
+ ((f->f_flags & O_ACCMODE) == O_RDWR)) {
+ if (fifo->has_tx_fifo) {
+ fifo->write_flags = f->f_flags;
+ } else {
+ dev_err(fifo->dt_device, "tried to open device for write but the transmit fifo is disabled\n");
+ return -EPERM;
+ }
+ }
+
+ if (((f->f_flags & O_ACCMODE) == O_RDONLY) ||
+ ((f->f_flags & O_ACCMODE) == O_RDWR)) {
+ if (fifo->has_rx_fifo) {
+ fifo->read_flags = f->f_flags;
+ } else {
+ dev_err(fifo->dt_device, "tried to open device for read but the receive fifo is disabled\n");
+ return -EPERM;
+ }
+ }
+
+ return 0;
+}
+
+static int axis_fifo_close(struct inode *inod, struct file *f)
+{
+ f->private_data = NULL;
+
+ return 0;
+}
+
+static const struct file_operations fops = {
+ .owner = THIS_MODULE,
+ .open = axis_fifo_open,
+ .release = axis_fifo_close,
+ .read = axis_fifo_read,
+ .write = axis_fifo_write
+};
+
+/* read named property from the device tree */
+static int get_dts_property(struct axis_fifo *fifo,
+ char *name, unsigned int *var)
+{
+ int rc;
+
+ rc = of_property_read_u32(fifo->dt_device->of_node, name, var);
+ if (rc) {
+ dev_err(fifo->dt_device, "couldn't read IP dts property '%s'",
+ name);
+ return rc;
+ }
+ dev_dbg(fifo->dt_device, "dts property '%s' = %u\n",
+ name, *var);
+
+ return 0;
+}
+
+static int axis_fifo_probe(struct platform_device *pdev)
+{
+ struct resource *r_irq; /* interrupt resources */
+ struct resource *r_mem; /* IO mem resources */
+ struct device *dev = &pdev->dev; /* OS device (from device tree) */
+ struct axis_fifo *fifo = NULL;
+
+ char device_name[32];
+
+ int rc = 0; /* error return value */
+
+ /* IP properties from device tree */
+ unsigned int rxd_tdata_width;
+ unsigned int txc_tdata_width;
+ unsigned int txd_tdata_width;
+ unsigned int tdest_width;
+ unsigned int tid_width;
+ unsigned int tuser_width;
+ unsigned int data_interface_type;
+ unsigned int has_tdest;
+ unsigned int has_tid;
+ unsigned int has_tkeep;
+ unsigned int has_tstrb;
+ unsigned int has_tuser;
+ unsigned int rx_fifo_depth;
+ unsigned int rx_programmable_empty_threshold;
+ unsigned int rx_programmable_full_threshold;
+ unsigned int axi_id_width;
+ unsigned int axi4_data_width;
+ unsigned int select_xpm;
+ unsigned int tx_fifo_depth;
+ unsigned int tx_programmable_empty_threshold;
+ unsigned int tx_programmable_full_threshold;
+ unsigned int use_rx_cut_through;
+ unsigned int use_rx_data;
+ unsigned int use_tx_control;
+ unsigned int use_tx_cut_through;
+ unsigned int use_tx_data;
+
+ /* ----------------------------
+ * init wrapper device
+ * ----------------------------
+ */
+
+ /* allocate device wrapper memory */
+ fifo = devm_kmalloc(dev, sizeof(*fifo), GFP_KERNEL);
+ if (!fifo)
+ return -ENOMEM;
+
+ dev_set_drvdata(dev, fifo);
+ fifo->dt_device = dev;
+
+ init_waitqueue_head(&fifo->read_queue);
+ init_waitqueue_head(&fifo->write_queue);
+
+ spin_lock_init(&fifo->read_queue_lock);
+ spin_lock_init(&fifo->write_queue_lock);
+
+ /* ----------------------------
+ * init device memory space
+ * ----------------------------
+ */
+
+ /* get iospace for the device */
+ r_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!r_mem) {
+ dev_err(fifo->dt_device, "invalid address\n");
+ rc = -ENODEV;
+ goto err_initial;
+ }
+
+ fifo->mem = r_mem;
+
+ /* request physical memory */
+ if (!request_mem_region(fifo->mem->start, resource_size(fifo->mem),
+ DRIVER_NAME)) {
+ dev_err(fifo->dt_device,
+ "couldn't lock memory region at 0x%pa\n",
+ &fifo->mem->start);
+ rc = -EBUSY;
+ goto err_initial;
+ }
+ dev_dbg(fifo->dt_device, "got memory location [0x%pa - 0x%pa]\n",
+ &fifo->mem->start, &fifo->mem->end);
+
+ /* map physical memory to kernel virtual address space */
+ fifo->base_addr = ioremap(fifo->mem->start, resource_size(fifo->mem));
+ if (!fifo->base_addr) {
+ dev_err(fifo->dt_device, "couldn't map physical memory\n");
+ rc = -ENOMEM;
+ goto err_mem;
+ }
+ dev_dbg(fifo->dt_device, "remapped memory to 0x%p\n", fifo->base_addr);
+
+ /* create unique device name */
+ snprintf(device_name, sizeof(device_name), "%s_%pa",
+ DRIVER_NAME, &fifo->mem->start);
+
+ dev_dbg(fifo->dt_device, "device name [%s]\n", device_name);
+
+ /* ----------------------------
+ * init IP
+ * ----------------------------
+ */
+
+ /* retrieve device tree properties */
+ rc = get_dts_property(fifo, "xlnx,axi-str-rxd-tdata-width",
+ &rxd_tdata_width);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,axi-str-txc-tdata-width",
+ &txc_tdata_width);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,axi-str-txd-tdata-width",
+ &txd_tdata_width);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,axis-tdest-width", &tdest_width);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,axis-tid-width", &tid_width);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,axis-tuser-width", &tuser_width);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,data-interface-type",
+ &data_interface_type);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,has-axis-tdest", &has_tdest);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,has-axis-tid", &has_tid);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,has-axis-tkeep", &has_tkeep);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,has-axis-tstrb", &has_tstrb);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,has-axis-tuser", &has_tuser);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,rx-fifo-depth", &rx_fifo_depth);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,rx-fifo-pe-threshold",
+ &rx_programmable_empty_threshold);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,rx-fifo-pf-threshold",
+ &rx_programmable_full_threshold);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,s-axi-id-width", &axi_id_width);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,s-axi4-data-width", &axi4_data_width);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,select-xpm", &select_xpm);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,tx-fifo-depth", &tx_fifo_depth);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,tx-fifo-pe-threshold",
+ &tx_programmable_empty_threshold);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,tx-fifo-pf-threshold",
+ &tx_programmable_full_threshold);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,use-rx-cut-through",
+ &use_rx_cut_through);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,use-rx-data", &use_rx_data);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,use-tx-ctrl", &use_tx_control);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,use-tx-cut-through",
+ &use_tx_cut_through);
+ if (rc)
+ goto err_unmap;
+ rc = get_dts_property(fifo, "xlnx,use-tx-data", &use_tx_data);
+ if (rc)
+ goto err_unmap;
+
+ /* check validity of device tree properties */
+ if (rxd_tdata_width != 32) {
+ dev_err(fifo->dt_device,
+ "rxd_tdata_width width [%u] unsupported\n",
+ rxd_tdata_width);
+ rc = -EIO;
+ goto err_unmap;
+ }
+ if (txd_tdata_width != 32) {
+ dev_err(fifo->dt_device,
+ "txd_tdata_width width [%u] unsupported\n",
+ txd_tdata_width);
+ rc = -EIO;
+ goto err_unmap;
+ }
+ if (has_tdest) {
+ dev_err(fifo->dt_device, "tdest not supported\n");
+ rc = -EIO;
+ goto err_unmap;
+ }
+ if (has_tid) {
+ dev_err(fifo->dt_device, "tid not supported\n");
+ rc = -EIO;
+ goto err_unmap;
+ }
+ if (has_tkeep) {
+ dev_err(fifo->dt_device, "tkeep not supported\n");
+ rc = -EIO;
+ goto err_unmap;
+ }
+ if (has_tstrb) {
+ dev_err(fifo->dt_device, "tstrb not supported\n");
+ rc = -EIO;
+ goto err_unmap;
+ }
+ if (has_tuser) {
+ dev_err(fifo->dt_device, "tuser not supported\n");
+ rc = -EIO;
+ goto err_unmap;
+ }
+ if (use_rx_cut_through) {
+ dev_err(fifo->dt_device, "rx cut-through not supported\n");
+ rc = -EIO;
+ goto err_unmap;
+ }
+ if (use_tx_cut_through) {
+ dev_err(fifo->dt_device, "tx cut-through not supported\n");
+ rc = -EIO;
+ goto err_unmap;
+ }
+ if (use_tx_control) {
+ dev_err(fifo->dt_device, "tx control not supported\n");
+ rc = -EIO;
+ goto err_unmap;
+ }
+
+ /* TODO
+ * these exist in the device tree but it's unclear what they do
+ * - select-xpm
+ * - data-interface-type
+ */
+
+ /* set device wrapper properties based on IP config */
+ fifo->rx_fifo_depth = rx_fifo_depth;
+ /* IP sets TDFV to fifo depth - 4 so we will do the same */
+ fifo->tx_fifo_depth = tx_fifo_depth - 4;
+ fifo->has_rx_fifo = use_rx_data;
+ fifo->has_tx_fifo = use_tx_data;
+
+ reset_ip_core(fifo);
+
+ /* ----------------------------
+ * init device interrupts
+ * ----------------------------
+ */
+
+ /* get IRQ resource */
+ r_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (!r_irq) {
+ dev_err(fifo->dt_device, "no IRQ found for 0x%pa\n",
+ &fifo->mem->start);
+ rc = -EIO;
+ goto err_unmap;
+ }
+
+ /* request IRQ */
+ fifo->irq = r_irq->start;
+ rc = request_irq(fifo->irq, &axis_fifo_irq, 0, DRIVER_NAME, fifo);
+ if (rc) {
+ dev_err(fifo->dt_device, "couldn't allocate interrupt %i\n",
+ fifo->irq);
+ goto err_unmap;
+ }
+
+ /* ----------------------------
+ * init char device
+ * ----------------------------
+ */
+
+ /* allocate device number */
+ rc = alloc_chrdev_region(&fifo->devt, 0, 1, DRIVER_NAME);
+ if (rc < 0)
+ goto err_irq;
+ dev_dbg(fifo->dt_device, "allocated device number major %i minor %i\n",
+ MAJOR(fifo->devt), MINOR(fifo->devt));
+
+ /* create driver file */
+ fifo->device = device_create(axis_fifo_driver_class, NULL, fifo->devt,
+ NULL, device_name);
+ if (!fifo->device) {
+ dev_err(fifo->dt_device,
+ "couldn't create driver file\n");
+ rc = -ENOMEM;
+ goto err_chrdev_region;
+ }
+ dev_set_drvdata(fifo->device, fifo);
+
+ /* create character device */
+ cdev_init(&fifo->char_device, &fops);
+ rc = cdev_add(&fifo->char_device, fifo->devt, 1);
+ if (rc < 0) {
+ dev_err(fifo->dt_device, "couldn't create character device\n");
+ goto err_dev;
+ }
+
+ /* create sysfs entries */
+ rc = sysfs_create_group(&fifo->device->kobj, &axis_fifo_attrs_group);
+ if (rc < 0) {
+ dev_err(fifo->dt_device, "couldn't register sysfs group\n");
+ goto err_cdev;
+ }
+
+ dev_info(fifo->dt_device, "axis-fifo created at %pa mapped to 0x%pa, irq=%i, major=%i, minor=%i\n",
+ &fifo->mem->start, &fifo->base_addr, fifo->irq,
+ MAJOR(fifo->devt), MINOR(fifo->devt));
+
+ return 0;
+
+err_cdev:
+ cdev_del(&fifo->char_device);
+err_dev:
+ device_destroy(axis_fifo_driver_class, fifo->devt);
+err_chrdev_region:
+ unregister_chrdev_region(fifo->devt, 1);
+err_irq:
+ free_irq(fifo->irq, fifo);
+err_unmap:
+ iounmap(fifo->base_addr);
+err_mem:
+ release_mem_region(fifo->mem->start, resource_size(fifo->mem));
+err_initial:
+ dev_set_drvdata(dev, NULL);
+ return rc;
+}
+
+static int axis_fifo_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct axis_fifo *fifo = dev_get_drvdata(dev);
+
+ sysfs_remove_group(&fifo->device->kobj, &axis_fifo_attrs_group);
+ cdev_del(&fifo->char_device);
+ dev_set_drvdata(fifo->device, NULL);
+ device_destroy(axis_fifo_driver_class, fifo->devt);
+ unregister_chrdev_region(fifo->devt, 1);
+ free_irq(fifo->irq, fifo);
+ iounmap(fifo->base_addr);
+ release_mem_region(fifo->mem->start, resource_size(fifo->mem));
+ dev_set_drvdata(dev, NULL);
+ return 0;
+}
+
+static const struct of_device_id axis_fifo_of_match[] = {
+ { .compatible = "xlnx,axi-fifo-mm-s-4.1", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, axis_fifo_of_match);
+
+static struct platform_driver axis_fifo_driver = {
+ .driver = {
+ .name = DRIVER_NAME,
+ .owner = THIS_MODULE,
+ .of_match_table = axis_fifo_of_match,
+ },
+ .probe = axis_fifo_probe,
+ .remove = axis_fifo_remove,
+};
+
+static int __init axis_fifo_init(void)
+{
+ pr_info("axis-fifo driver loaded with parameters read_timeout = %i, write_timeout = %i\n",
+ read_timeout, write_timeout);
+ axis_fifo_driver_class = class_create(THIS_MODULE, DRIVER_NAME);
+ return platform_driver_register(&axis_fifo_driver);
+}
+
+module_init(axis_fifo_init);
+
+static void __exit axis_fifo_exit(void)
+{
+ platform_driver_unregister(&axis_fifo_driver);
+ class_destroy(axis_fifo_driver_class);
+}
+
+module_exit(axis_fifo_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jacob Feder <jacobsfeder@gmail.com>");
+MODULE_DESCRIPTION("Xilinx AXI-Stream FIFO v4.1 IP core driver");
diff --git a/drivers/staging/axis-fifo/axis-fifo.txt b/drivers/staging/axis-fifo/axis-fifo.txt
new file mode 100644
index 000000000000..85d88c010e72
--- /dev/null
+++ b/drivers/staging/axis-fifo/axis-fifo.txt
@@ -0,0 +1,89 @@
+Xilinx AXI-Stream FIFO v4.1 IP core
+
+This IP core has read and write AXI-Stream FIFOs, the contents of which can
+be accessed from the AXI4 memory-mapped interface. This is useful for
+transferring data from a processor into the FPGA fabric. The driver creates
+a character device that can be read/written to with standard
+open/read/write/close.
+
+See Xilinx PG080 document for IP details.
+
+Currently supports only store-forward mode with a 32-bit
+AXI4-Lite interface. DOES NOT support:
+ - cut-through mode
+ - AXI4 (non-lite)
+
+Required properties:
+- compatible: Should be "xlnx,axi-fifo-mm-s-4.1"
+- interrupt-names: Should be "interrupt"
+- interrupt-parent: Should be <&intc>
+- interrupts: Should contain interrupts lines.
+- reg: Should contain registers location and length.
+- xlnx,axi-str-rxd-protocol: Should be "XIL_AXI_STREAM_ETH_DATA"
+- xlnx,axi-str-rxd-tdata-width: Should be <0x20>
+- xlnx,axi-str-txc-protocol: Should be "XIL_AXI_STREAM_ETH_CTRL"
+- xlnx,axi-str-txc-tdata-width: Should be <0x20>
+- xlnx,axi-str-txd-protocol: Should be "XIL_AXI_STREAM_ETH_DATA"
+- xlnx,axi-str-txd-tdata-width: Should be <0x20>
+- xlnx,axis-tdest-width: AXI-Stream TDEST width
+- xlnx,axis-tid-width: AXI-Stream TID width
+- xlnx,axis-tuser-width: AXI-Stream TUSER width
+- xlnx,data-interface-type: Should be <0x0>
+- xlnx,has-axis-tdest: Should be <0x0> (this feature isn't supported)
+- xlnx,has-axis-tid: Should be <0x0> (this feature isn't supported)
+- xlnx,has-axis-tkeep: Should be <0x0> (this feature isn't supported)
+- xlnx,has-axis-tstrb: Should be <0x0> (this feature isn't supported)
+- xlnx,has-axis-tuser: Should be <0x0> (this feature isn't supported)
+- xlnx,rx-fifo-depth: Depth of RX FIFO in words
+- xlnx,rx-fifo-pe-threshold: RX programmable empty interrupt threshold
+- xlnx,rx-fifo-pf-threshold: RX programmable full interrupt threshold
+- xlnx,s-axi-id-width: Should be <0x4>
+- xlnx,s-axi4-data-width: Should be <0x20>
+- xlnx,select-xpm: Should be <0x0>
+- xlnx,tx-fifo-depth: Depth of TX FIFO in words
+- xlnx,tx-fifo-pe-threshold: TX programmable empty interrupt threshold
+- xlnx,tx-fifo-pf-threshold: TX programmable full interrupt threshold
+- xlnx,use-rx-cut-through: Should be <0x0> (this feature isn't supported)
+- xlnx,use-rx-data: <0x1> if RX FIFO is enabled, <0x0> otherwise
+- xlnx,use-tx-ctrl: Should be <0x0> (this feature isn't supported)
+- xlnx,use-tx-cut-through: Should be <0x0> (this feature isn't supported)
+- xlnx,use-tx-data: <0x1> if TX FIFO is enabled, <0x0> otherwise
+
+Example:
+
+axi_fifo_mm_s_0: axi_fifo_mm_s@43c00000 {
+ compatible = "xlnx,axi-fifo-mm-s-4.1";
+ interrupt-names = "interrupt";
+ interrupt-parent = <&intc>;
+ interrupts = <0 29 4>;
+ reg = <0x43c00000 0x10000>;
+ xlnx,axi-str-rxd-protocol = "XIL_AXI_STREAM_ETH_DATA";
+ xlnx,axi-str-rxd-tdata-width = <0x20>;
+ xlnx,axi-str-txc-protocol = "XIL_AXI_STREAM_ETH_CTRL";
+ xlnx,axi-str-txc-tdata-width = <0x20>;
+ xlnx,axi-str-txd-protocol = "XIL_AXI_STREAM_ETH_DATA";
+ xlnx,axi-str-txd-tdata-width = <0x20>;
+ xlnx,axis-tdest-width = <0x4>;
+ xlnx,axis-tid-width = <0x4>;
+ xlnx,axis-tuser-width = <0x4>;
+ xlnx,data-interface-type = <0x0>;
+ xlnx,has-axis-tdest = <0x0>;
+ xlnx,has-axis-tid = <0x0>;
+ xlnx,has-axis-tkeep = <0x0>;
+ xlnx,has-axis-tstrb = <0x0>;
+ xlnx,has-axis-tuser = <0x0>;
+ xlnx,rx-fifo-depth = <0x200>;
+ xlnx,rx-fifo-pe-threshold = <0x2>;
+ xlnx,rx-fifo-pf-threshold = <0x1fb>;
+ xlnx,s-axi-id-width = <0x4>;
+ xlnx,s-axi4-data-width = <0x20>;
+ xlnx,select-xpm = <0x0>;
+ xlnx,tx-fifo-depth = <0x8000>;
+ xlnx,tx-fifo-pe-threshold = <0x200>;
+ xlnx,tx-fifo-pf-threshold = <0x7ffb>;
+ xlnx,use-rx-cut-through = <0x0>;
+ xlnx,use-rx-data = <0x0>;
+ xlnx,use-tx-ctrl = <0x0>;
+ xlnx,use-tx-cut-through = <0x0>;
+ xlnx,use-tx-data = <0x1>;
+};