[PATCH v2 3/3] Linn Ethernet packet sniffer driver

Stathis Voukelatos
2015-02-17T14:03:33Z

Driver for the Ethernet Mii packet sniffer H/W module found in
the IMG Pistachio SoC.

Signed-off-by: Stathis Voukelatos <stathis.voukelatos-zgcZaY4qg+21Qrn1Bg8BZw@public.gmane.org>
---
drivers/net/pkt-sniffer/Kconfig | 11 +
drivers/net/pkt-sniffer/Makefile | 4 +
drivers/net/pkt-sniffer/backends/ether/channel.c | 392 ++++++++++++++++++++++
drivers/net/pkt-sniffer/backends/ether/channel.h | 81 +++++
drivers/net/pkt-sniffer/backends/ether/hw.h | 46 +++
drivers/net/pkt-sniffer/backends/ether/platform.c | 301 +++++++++++++++++
6 files changed, 835 insertions(+)
create mode 100644 drivers/net/pkt-sniffer/backends/ether/channel.c
create mode 100644 drivers/net/pkt-sniffer/backends/ether/channel.h
create mode 100644 drivers/net/pkt-sniffer/backends/ether/hw.h
create mode 100644 drivers/net/pkt-sniffer/backends/ether/platform.c

diff --git a/drivers/net/pkt-sniffer/Kconfig b/drivers/net/pkt-sniffer/Kconfig
index 53ffcc1..b7c7f6b 100644
--- a/drivers/net/pkt-sniffer/Kconfig
+++ b/drivers/net/pkt-sniffer/Kconfig
@@ -6,3 +6,14 @@ menuconfig PKT_SNIFFER
The core driver can also be built as a module. If so, the module
will be called snf_core.

+config PKT_SNIFFER_ETHER
+ tristate "Ethernet packet sniffer"
+ depends on PKT_SNIFFER
+ help
+ Say Y here if you want to use the Ethernet packet sniffer
+ module by Linn Products Ltd. It can be found in the upcoming
+ Pistachio SoC by Imagination Technologies.
+
+ The driver can also be built as a module. If so, the module
+ will be called snf_ether.
+
diff --git a/drivers/net/pkt-sniffer/Makefile b/drivers/net/pkt-sniffer/Makefile
index 31dc396..89a3c60 100644
--- a/drivers/net/pkt-sniffer/Makefile
+++ b/drivers/net/pkt-sniffer/Makefile
@@ -1,3 +1,7 @@
snf_core-y += core/netdev.o
snf_core-y += core/module.o
obj-$(CONFIG_PKT_SNIFFER) += snf_core.o
+
+snf_ether-y += backends/ether/platform.o
+snf_ether-y += backends/ether/channel.o
+obj-$(CONFIG_PKT_SNIFFER_ETHER) += snf_ether.o
diff --git a/drivers/net/pkt-sniffer/backends/ether/channel.c b/drivers/net/pkt-sniffer/backends/ether/channel.c
new file mode 100644
index 0000000..a7fed4e
--- /dev/null
+++ b/drivers/net/pkt-sniffer/backends/ether/channel.c
@@ -0,0 +1,392 @@
+/*
+ * Ethernet Mii packet sniffer driver
+ * - channel functions
+ *
+ * Copyright (C) 2015 Linn Products Ltd
+ *
+ * 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.
+ *
+ * Written by:
+ * Stathis Voukelatos <stathis.voukelatos-zgcZaY4qg+21Qrn1Bg8BZw@public.gmane.org>
+ */
+#include <linux/io.h>
+#include <linux/hrtimer.h>
+#include <linux/pkt_sniffer.h>
+#include "../../core/snf_core.h"
+#include "hw.h"
+#include "channel.h"
+
+#define to_ether_snf_chan(dev) container_of(dev, struct ether_snf_chan, chan)
+
+/* Checks if the supplied command string is compatible with the
+ * capabilities of the H/W. The command string consists of a series
+ * of bytes in the following format
+ * --------------------------------
+ * | CMD | DATA | CMD | DATA | ....
+ * --------------------------------
+ */
+static bool validate_pattern(
+ struct ether_snf_chan *ch,
+ const u8 *buf,
+ int count)
+{
+ int i, complete, max_copy_bytes;
+ int ts = 0;
+ int copy_before = 0;
+ int copy_after = 0;
+
+ if (count > ch->max_cmds)
+ return false;
+
+ /* Iterate through the commands in the string */
+ for (i = 0, complete = 0; (i < count) && !complete; i++) {
+ u8 cmd = buf[2*i];
+
+ switch (cmd) {
+ case PTN_CMD_DONTCARE:
+ case PTN_CMD_MATCH:
+ break;
+
+ case PTN_CMD_MATCHSTAMP:
+ /* The timestamp needs to be word-aligned in the FIFO
+ * therefore, the number of 'copy' commands before it
+ * needs to be a multiple of 4
+ */
+ if (copy_before & 3)
+ return false;
+ /* Signal that a timestamp will be present */
+ ts = 1;
+ break;
+
+ case PTN_CMD_COPY:
+ /* Increment count of bytes that will be returned */
+ if (ts)
+ copy_after++;
+ else
+ copy_before++;
+ break;
+
+ case PTN_CMD_COPYDONE:
+ /* Increment count of bytes that will be returned
+ * This command terminates the string
+ */
+ if (ts)
+ copy_after++;
+ else
+ copy_before++;
+ /* This command completes the command string */
+ complete = 1;
+ break;
+
+ default:
+ /* Invalid command id */
+ return false;
+ }
+ }
+
+ /* Check if the string was properly terminated
+ * and contained valid number of commands
+ */
+ if (complete) {
+ max_copy_bytes = ch->fifo_blk_words * 4;
+ if (ts)
+ max_copy_bytes -= 4;
+ /* Too many copy commands will case the FIFO
+ * to wrap around
+ */
+ if ((copy_before + copy_after) > max_copy_bytes)
+ return false;
+ ch->nfb_before = copy_before;
+ ch->nfb_after = copy_after;
+ ch->evt.ts_valid = ts;
+ ch->evt.len = ch->nfb_before + ch->nfb_after;
+ return true;
+ }
+
+ /* Command string not terminated */
+ return false;
+}
+
+/* Channel methods */
+
+/* Enables the channel */
+static int esnf_start(struct snf_chan *dev)
+{
+ struct ether_snf_chan *ch = to_ether_snf_chan(dev);
+
+ if (!ch->started) {
+ ch->evt.ts = 0;
+ /* Enable interrupts */
+ iowrite32(ch->data_irq_bit | ch->full_irq_bit,
+ ch->regs + SET_INTERRUPT_ENABLE);
+ /* Enable the packet matching logic */
+ iowrite32(ENABLE_BIT, ch->reg_enable);
+
+ ch->started = 1;
+ dev_info(ch->dev, "%s: started\n", ch->name);
+ } else {
+ dev_dbg(ch->dev, "%s: already running\n", ch->name);
+ }
+
+ return 0;
+}
+
+/* Disables the channel */
+static int esnf_stop(struct snf_chan *dev)
+{
+ struct ether_snf_chan *ch = to_ether_snf_chan(dev);
+
+ if (ch->started) {
+ /* Disable interrupts */
+ iowrite32(ch->data_irq_bit | ch->full_irq_bit,
+ ch->regs + CLEAR_INTERRUPT_ENABLE);
+ /* Stop the sniffer channel */
+ iowrite32(0, ch->reg_enable);
+ /* Clear any pending interrupts */
+ iowrite32(ch->data_irq_bit | ch->full_irq_bit,
+ ch->regs + INTERRUPT_STATUS);
+
+ ch->started = 0;
+ dev_info(ch->dev, "%s: stopped\n", ch->name);
+ } else {
+ dev_dbg(ch->dev, "%s: already stopped\n", ch->name);
+ }
+
+ return 0;
+}
+
+/* Sets the command string (pattern) for the channel
+ * The bytes in the pattern buffer are in the following order:
+ */
+static int esnf_set_pattern(struct snf_chan *dev, const u8 *pattern, int count)
+{
+ struct ether_snf_chan *ch = to_ether_snf_chan(dev);
+ int i, shift = 0;
+ u32 val = 0, *ptr;
+
+ dev_info(ch->dev, "%s: set cmd pattern with %d entries\n",
+ ch->name, count);
+
+ if (ch->started) {
+ dev_err(ch->dev,
+ "%s: cannot apply cmd pattern. Channel is active\n",
+ ch->name);
+ return -EBUSY;
+ }
+
+ if (!validate_pattern(ch, pattern, count)) {
+ dev_err(ch->dev,
+ "%s: invalid cmd pattern\n",
+ ch->name);
+ return -EINVAL;
+ }
+
+ for (ptr = ch->cmd_ram, i = 0, shift = 24; i < (2*count); i++) {
+ val |= ((u32)pattern[i]) << shift;
+ if (!shift) {
+ iowrite32(val, ptr++);
+ val = 0;
+ shift = 24;
+ } else {
+ shift -= 8;
+ }
+ }
+ if (shift)
+ iowrite32(val, ptr);
+
+ return 0;
+}
+
+/* Returns max number of commands supported by the channel */
+static int esnf_max_ptn_entries(struct snf_chan *dev)
+{
+ struct ether_snf_chan *ch = to_ether_snf_chan(dev);
+
+ return ch->max_cmds;
+}
+
+static int esnf_ts_enabled(struct snf_chan *dev)
+{
+ struct ether_snf_chan *ch = to_ether_snf_chan(dev);
+
+ return ch->evt.ts_valid;
+}
+
+/* Gray decoder */
+static u32 gray_decode(u32 gray)
+{
+ gray ^= (gray >> 16);
+ gray ^= (gray >> 8);
+ gray ^= (gray >> 4);
+ gray ^= (gray >> 2);
+ gray ^= (gray >> 1);
+ return gray;
+}
+
+/* Read a block from the data FIFO */
+static void read_fifo_data(struct ether_snf_chan *ch)
+{
+ int i;
+ u32 val, *ptr;
+ int ts = ch->evt.ts_valid;
+ int dw = ch->fifo_blk_words;
+ int bytes_before = ch->nfb_before;
+ int bytes_after = ch->nfb_after;
+
+ ptr = (u32 *)ch->evt.data;
+ for (i = 0; i < dw; i++) {
+ val = ioread32(ch->reg_fifo);
+ if (bytes_before > 0) {
+ /* Bytes before the timestamp */
+ *ptr++ = cpu_to_be32(val);
+ bytes_before -= 4;
+ } else if (ts) {
+ ch->raw_tstamp = gray_decode(val);
+ /* First timestamp since the channel was started.
+ * Initialise the timecounter
+ */
+ if (!ch->evt.ts)
+ timecounter_init(
+ &ch->tc,
+ &ch->cc,
+ ktime_to_ns(ktime_get_real()));
+ ch->evt.ts = timecounter_read(&ch->tc);
+ ts = 0;
+ } else if (bytes_after > 0) {
+ /* Bytes after the timestamp */
+ *ptr++ = cpu_to_be32(val);
+ bytes_after -= 4;
+ }
+ }
+}
+
+/* Read method for the timestamp cycle counter
+ * Returns the last received timestamp value
+ */
+static cycle_t esnf_cyclecounter_read(const struct cyclecounter *cc)
+{
+ struct ether_snf_chan *ch = container_of(cc, struct ether_snf_chan, cc);
+
+ return ch->raw_tstamp;
+}
+
+/* Initialises a sniffer channel */
+int channel_init(
+ struct ether_snf_chan *ch,
+ struct platform_device *pdev,
+ void *regs,
+ int fifo_blk_words,
+ u32 tstamp_hz,
+ u32 tstamp_shift,
+ u32 tstamp_bits,
+ int tx)
+{
+ struct resource *res;
+ u32 *ptr;
+ int i;
+
+ ch->regs = regs;
+ ch->dev = &pdev->dev;
+ ch->data_irq_bit = tx ? TX_DATA_IRQ_BIT : RX_DATA_IRQ_BIT;
+ ch->full_irq_bit = tx ? TX_FULL_IRQ_BIT : RX_FULL_IRQ_BIT;
+ ch->reg_enable = ch->regs +
+ (tx ? TX_SNIFFER_ENABLE : RX_SNIFFER_ENABLE);
+ ch->reg_fifo = ch->regs + (tx ? TX_FIFO_DAT : RX_FIFO_DAT);
+
+ /* Retrieve and remap the address space for the command memory */
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+ tx ? "tx-ram" : "rx-ram");
+ if (!res)
+ return -ENOSYS;
+ ch->cmd_ram = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(ch->cmd_ram))
+ return PTR_ERR(ch->cmd_ram);
+
+ /* It is 2 bytes/command, hence divide by 2 */
+ ch->max_cmds = resource_size(res) / 2;
+
+ /* Initialise the command string RAM */
+ for (i = 0, ptr = ch->cmd_ram; i < resource_size(res); i += 4)
+ iowrite32((PTN_CMD_DONTCARE << 24) | (PTN_CMD_DONTCARE << 8),
+ ptr++);
+
+ ch->fifo_blk_words = fifo_blk_words;
+ ch->started = 0;
+
+ /* Initialise the timestamp cycle counter */
+ ch->cc.read = esnf_cyclecounter_read;
+ ch->cc.mask = CLOCKSOURCE_MASK(tstamp_bits);
+ ch->cc.mult = clocksource_hz2mult(tstamp_hz, tstamp_shift);
+ ch->cc.shift = tstamp_shift;
+
+ /* Register the channel methods */
+ ch->chan.start = esnf_start;
+ ch->chan.stop = esnf_stop;
+ ch->chan.set_pattern = esnf_set_pattern;
+ ch->chan.max_ptn_entries = esnf_max_ptn_entries;
+ ch->chan.ts_enabled = esnf_ts_enabled;
+
+ strncpy(ch->name, tx ? "TX" : "RX", MAX_CHAN_NAME_SIZE - 1);
+
+ dev_dbg(ch->dev, "%s: channel initialized\n", ch->name);
+
+ return 0;
+}
+
+/* Registers the channel with the sniffer core module */
+int channel_register(struct ether_snf_chan *ch, const char *name)
+{
+ int ret;
+
+ ret = snf_channel_add(&ch->chan, name);
+ if (ret < 0)
+ return ret;
+
+ dev_info(ch->dev, "%s channel added\n", ch->name);
+ return 0;
+}
+
+/* Unregisters the channel */
+int channel_unregister(struct ether_snf_chan *ch)
+{
+ int ret;
+
+ ch->chan.stop(&ch->chan);
+ ret = snf_channel_remove(&ch->chan);
+ if (!ret)
+ dev_info(ch->dev, "%s channel removed\n", ch->name);
+ return ret;
+}
+
+/* Process match event data */
+void channel_data_available(struct ether_snf_chan *ch)
+{
+ int ret;
+
+ dev_dbg(ch->dev, "%s match event\n", ch->name);
+
+ read_fifo_data(ch);
+ ret = snf_channel_notify_match(&ch->chan, &ch->evt);
+ if (ret < 0)
+ dev_err(ch->dev, "%s: event notification failed\n", ch->name);
+}
+
+/* Suspend opertion */
+int channel_suspend(struct ether_snf_chan *ch)
+{
+ return snf_channel_suspend(&ch->chan);
+}
+
+/* Resume operation */
+int channel_resume(struct ether_snf_chan *ch)
+{
+ return snf_channel_resume(&ch->chan);
+}
+
diff --git a/drivers/net/pkt-sniffer/backends/ether/channel.h b/drivers/net/pkt-sniffer/backends/ether/channel.h
new file mode 100644
index 0000000..35ed891
--- /dev/null
+++ b/drivers/net/pkt-sniffer/backends/ether/channel.h
@@ -0,0 +1,81 @@
+/*
+ * Ethernet Mii packet sniffer driver
+ * - channel interface
+ *
+ * Copyright (C) 2015 Linn Products Ltd
+ *
+ * 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.
+ *
+ * Written by:
+ * Stathis Voukelatos <stathis.voukelatos-zgcZaY4qg+21Qrn1Bg8BZw@public.gmane.org>
+ */
+#ifndef _ETHER_SNIFFER_CHANNEL_H_
+#define _ETHER_SNIFFER_CHANNEL_H_
+
+#include <linux/platform_device.h>
+#include <linux/clocksource.h>
+#include "../../core/snf_core.h"
+
+#define MAX_CHAN_NAME_SIZE 5
+
+struct ether_snf_chan {
+ /* Sniffer core structure */
+ struct snf_chan chan;
+ /* Pointer to device struct */
+ struct device *dev;
+ /* Registers */
+ u8 __iomem *regs;
+ /* Command string memory */
+ u32 __iomem *cmd_ram;
+ /* Bit number for the data IRQ */
+ int data_irq_bit;
+ /* Bit number for the FIFO full IRQ */
+ int full_irq_bit;
+ /* Channel enable register */
+ u8 __iomem *reg_enable;
+ /* Data FIFO register */
+ u8 __iomem *reg_fifo;
+ /* Max number of commands in the string */
+ int max_cmds;
+ /* Max matching bytes that can fit in a FIFO block */
+ int fifo_blk_words;
+ /* Number of bytes in the FIFO before the timestamp */
+ int nfb_before;
+ /* Number of bytes in the FIFO after the timestamp */
+ int nfb_after;
+ /* Channel active flag */
+ int started;
+ /* Last raw timestamp from the FIFO */
+ u32 raw_tstamp;
+ /* Channel name (only used by debug messages) */
+ char name[MAX_CHAN_NAME_SIZE];
+ /* Struct to hold data from a packet match */
+ struct snf_match_evt evt;
+ /* Cycle and time counters for tstamp handling */
+ struct cyclecounter cc;
+ struct timecounter tc;
+};
+
+int channel_init(
+ struct ether_snf_chan *ch,
+ struct platform_device *pdev,
+ void *regs,
+ int fifo_blk_words,
+ u32 tstamp_hz,
+ u32 tstamp_shift,
+ u32 tstamp_bits,
+ int tx);
+int channel_register(struct ether_snf_chan *ch, const char *name);
+int channel_unregister(struct ether_snf_chan *ch);
+void channel_data_available(struct ether_snf_chan *ch);
+int channel_suspend(struct ether_snf_chan *ch);
+int channel_resume(struct ether_snf_chan *ch);
+
+#endif
diff --git a/drivers/net/pkt-sniffer/backends/ether/hw.h b/drivers/net/pkt-sniffer/backends/ether/hw.h
new file mode 100644
index 0000000..edb1093
--- /dev/null
+++ b/drivers/net/pkt-sniffer/backends/ether/hw.h
@@ -0,0 +1,46 @@
+/*
+ * Ethernet Mii packet sniffer driver
+ * - register map
+ *
+ * Copyright (C) 2015 Linn Products Ltd
+ *
+ * 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.
+ *
+ * Written by:
+ * Stathis Voukelatos <stathis.voukelatos-zgcZaY4qg+21Qrn1Bg8BZw@public.gmane.org>
+ */
+#ifndef _ETHER_SNIFFER_HW_H_
+#define _ETHER_SNIFFER_HW_H_
+
+#include <linux/bitops.h>
+
+/* Registers */
+#define INTERRUPT_ENABLE 0x00
+#define SET_INTERRUPT_ENABLE 0x04
+#define CLEAR_INTERRUPT_ENABLE 0x08
+#define INTERRUPT_STATUS 0x0c
+#define TX_FIFO_DAT 0x10
+#define RX_FIFO_DAT 0x14
+#define TX_FIFO_OCC 0x18
+#define RX_FIFO_OCC 0x1c
+#define TX_SNIFFER_ENABLE 0x20
+#define RX_SNIFFER_ENABLE 0x24
+
+/* IRQ register bits */
+#define TX_DATA_IRQ_BIT BIT(0)
+#define RX_DATA_IRQ_BIT BIT(1)
+#define TX_FULL_IRQ_BIT BIT(2)
+#define RX_FULL_IRQ_BIT BIT(3)
+
+/* Enable register bits */
+#define ENABLE_BIT BIT(0)
+
+#endif
+
diff --git a/drivers/net/pkt-sniffer/backends/ether/platform.c b/drivers/net/pkt-sniffer/backends/ether/platform.c
new file mode 100644
index 0000000..06b26b5
--- /dev/null
+++ b/drivers/net/pkt-sniffer/backends/ether/platform.c
@@ -0,0 +1,301 @@
+/*
+ * Ethernet Mii packet sniffer driver
+ *
+ * Copyright (C) 2015 Linn Products Ltd
+ *
+ * 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.
+ *
+ * Written by:
+ * Stathis Voukelatos <stathis.voukelatos-zgcZaY4qg+21Qrn1Bg8BZw@public.gmane.org>
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include "../../core/snf_core.h"
+#include "hw.h"
+#include "channel.h"
+
+/* Names for the TX and RX channel net interfaces */
+static const char tx_channel_name[] = "snfethtx%d";
+static const char rx_channel_name[] = "snfethrx%d";
+
+struct ether_snf {
+ u8 __iomem *regs;
+ int irq;
+ struct clk *sys_clk;
+ struct clk *ts_clk;
+ struct ether_snf_chan txc;
+ struct ether_snf_chan rxc;
+};
+
+/* Interrupt handler */
+static irqreturn_t esnf_interrupt(int irq, void *dev_id)
+{
+ struct platform_device *pdev = (struct platform_device *)dev_id;
+ struct ether_snf *esnf = (struct ether_snf *)platform_get_drvdata(pdev);
+ u32 irq_status;
+
+ if (unlikely(esnf->irq != irq))
+ return IRQ_NONE;
+
+ irq_status = ioread32(esnf->regs + INTERRUPT_STATUS) &
+ ioread32(esnf->regs + INTERRUPT_ENABLE);
+
+ dev_dbg(&pdev->dev, "irq: 0x%08x\n", irq_status);
+
+ /* TX FIFO full */
+ if (unlikely(irq_status & TX_FULL_IRQ_BIT))
+ dev_notice(&pdev->dev, "TX FIFO full\n");
+
+ /* RX FIFO full */
+ if (unlikely(irq_status & RX_FULL_IRQ_BIT))
+ dev_notice(&pdev->dev, "RX FIFO full\n");
+
+ /* TX match data available */
+ if (irq_status & TX_DATA_IRQ_BIT) {
+ dev_dbg(&pdev->dev, "TX data\n");
+ channel_data_available(&esnf->txc);
+ }
+
+ /* RX match data available */
+ if (irq_status & RX_DATA_IRQ_BIT) {
+ dev_dbg(&pdev->dev, "RX data\n");
+ channel_data_available(&esnf->rxc);
+ }
+
+ /* Clear interrupts */
+ iowrite32(irq_status, esnf->regs + INTERRUPT_STATUS);
+
+ return IRQ_HANDLED;
+}
+
+/* Called when the packet sniffer device is bound with the driver */
+static int esnf_driver_probe(struct platform_device *pdev)
+{
+ struct ether_snf *esnf;
+ struct resource *res;
+ int ret, irq;
+ u32 fifo_blk_words, ts_hz, ts_shift, ts_bits;
+ void __iomem *regs;
+ struct device_node *ofn = pdev->dev.of_node;
+
+ /* Allocate the device data structure */
+ esnf = devm_kzalloc(&pdev->dev, sizeof(*esnf), GFP_KERNEL);
+ if (!esnf)
+ return -ENOMEM;
+
+ /* Retrieve and remap register memory space */
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
+ regs = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(regs))
+ return PTR_ERR(regs);
+ esnf->regs = regs;
+
+ if (!ofn)
+ return -ENODEV;
+
+ /* Read requirede properties from the device tree node */
+ ret = of_property_read_u32(
+ ofn,
+ "fifo-block-words",
+ &fifo_blk_words);
+ if (ret < 0)
+ return ret;
+
+ if (((fifo_blk_words - 1)*4) > MAX_MATCH_BYTES) {
+ dev_err(&pdev->dev,
+ "Invalid FIFO block size entry in device tree\n");
+ return -EINVAL;
+ }
+
+ ret = of_property_read_u32(
+ ofn,
+ "tstamp-hz",
+ &ts_hz);
+ if (ret < 0)
+ return ret;
+
+ ret = of_property_read_u32(
+ ofn,
+ "tstamp-shift",
+ &ts_shift);
+ if (ret < 0)
+ return ret;
+
+ ret = of_property_read_u32(
+ ofn,
+ "tstamp-bits",
+ &ts_bits);
+ if (ret < 0)
+ return ret;
+
+ /* Enable peripheral bus and timstamp clocks */
+ esnf->sys_clk = devm_clk_get(&pdev->dev, "sys");
+ if (IS_ERR(esnf->sys_clk)) {
+ ret = PTR_ERR(esnf->sys_clk);
+ return ret;
+ }
+ ret = clk_prepare_enable(esnf->sys_clk);
+ if (ret < 0)
+ return ret;
+
+ esnf->ts_clk = devm_clk_get(&pdev->dev, "tstamp");
+ if (IS_ERR(esnf->ts_clk)) {
+ ret = PTR_ERR(esnf->ts_clk);
+ goto fail1;
+ }
+ ret = clk_prepare_enable(esnf->ts_clk);
+ if (ret < 0)
+ goto fail1;
+
+ /* Initialise the TX and RX channels */
+ ret = channel_init(
+ &esnf->txc,
+ pdev,
+ regs,
+ fifo_blk_words,
+ ts_hz,
+ ts_shift,
+ ts_bits,
+ 1);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to init TX channel (%d)\n", ret);
+ goto fail2;
+ }
+ ret = channel_init(
+ &esnf->rxc,
+ pdev,
+ regs,
+ fifo_blk_words,
+ ts_hz,
+ ts_shift,
+ ts_bits,
+ 0);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to init RX channel (%d)\n", ret);
+ goto fail2;
+ }
+
+ /* Register the channels with the sniffer core module */
+ ret = channel_register(&esnf->txc, tx_channel_name);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to register TX chan (%d)\n", ret);
+ goto fail2;
+ }
+ ret = channel_register(&esnf->rxc, rx_channel_name);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to register RX chan (%d)\n", ret);
+ goto fail3;
+ }
+
+ platform_set_drvdata(pdev, esnf);
+
+ /* Register the interrupt handler */
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ goto fail4;
+ esnf->irq = irq;
+ ret = devm_request_irq(
+ &pdev->dev,
+ irq,
+ esnf_interrupt,
+ 0,
+ KBUILD_MODNAME,
+ pdev);
+ if (ret < 0)
+ goto fail4;
+
+ return 0;
+
+fail4:
+ channel_unregister(&esnf->rxc);
+fail3:
+ channel_unregister(&esnf->txc);
+fail2:
+ clk_disable_unprepare(esnf->ts_clk);
+fail1:
+ clk_disable_unprepare(esnf->sys_clk);
+ return ret;
+}
+
+/* Called when the packet sniffer device unregisters with the driver */
+static int esnf_driver_remove(struct platform_device *pdev)
+{
+ struct ether_snf *esnf = (struct ether_snf *)platform_get_drvdata(pdev);
+ int ret;
+
+ ret = channel_unregister(&esnf->txc);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to unregister TX chan (%d)\n", ret);
+ return ret;
+ }
+ ret = channel_unregister(&esnf->rxc);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to unregister RX chan (%d)\n", ret);
+ return ret;
+ }
+ clk_disable_unprepare(esnf->ts_clk);
+ clk_disable_unprepare(esnf->sys_clk);
+ return 0;
+}
+
+#ifdef CONFIG_PM
+/* Driver suspend method */
+static int esnf_driver_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct ether_snf *esnf = (struct ether_snf *)platform_get_drvdata(pdev);
+
+ channel_suspend(&esnf->txc);
+ channel_suspend(&esnf->rxc);
+ return 0;
+}
+
+/* Driver resume method */
+static int esnf_driver_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct ether_snf *esnf = (struct ether_snf *)platform_get_drvdata(pdev);
+
+ channel_resume(&esnf->txc);
+ channel_resume(&esnf->rxc);
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(esnf_pm_ops, esnf_driver_suspend, esnf_driver_resume);
+#endif
+
+static const struct of_device_id esnf_of_match_table[] = {
+ { .compatible = "linn,eth-sniffer" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, esnf_of_match_table);
+
+static struct platform_driver esnf_platform_driver = {
+ .driver = {
+ .name = KBUILD_MODNAME,
+#ifdef CONFIG_PM
+ .pm = &esnf_pm_ops,
+#endif
+ .of_match_table = esnf_of_match_table,
+ },
+ .probe = esnf_driver_probe,
+ .remove = esnf_driver_remove,
+};
+
+module_platform_driver(esnf_platform_driver);
+
+MODULE_DESCRIPTION("Linn Ethernet Packet Sniffer");
+MODULE_AUTHOR("Linn Products Ltd");
+MODULE_LICENSE("GPL v2");
+
--
1.9.1

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