WAN: Add IXP4xx HSS HDLC driver.

Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>

1 files changed, 1357 insertions, 0 deletions

diff --git a/drivers/net/wan/ixp4xx_hss.c b/drivers/net/wan/ixp4xx_hss.c
new file mode 100644
index 0000000..fa3ce81
--- /dev/null
+++ b/drivers/net/wan/ixp4xx_hss.c
@@ -0,0 +1,1357 @@
+/*
+ * Intel IXP4xx HSS (synchronous serial port) driver for Linux
+ *
+ * Copyright (C) 2007-2008 Krzysztof Hałasa <khc@pm.waw.pl>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License
+ * as published by the Free Software Foundation.
+ */
+
+#include <linux/bitops.h>
+#include <linux/cdev.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/fs.h>
+#include <linux/hdlc.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/poll.h>
+#include <mach/npe.h>
+#include <mach/qmgr.h>
+
+#define DEBUG_QUEUES		0
+#define DEBUG_DESC		0
+#define DEBUG_RX		0
+#define DEBUG_TX		0
+#define DEBUG_PKT_BYTES		0
+#define DEBUG_CLOSE		0
+
+#define DRV_NAME		"ixp4xx_hss"
+
+#define PKT_EXTRA_FLAGS		0 /* orig 1 */
+#define PKT_NUM_PIPES		1 /* 1, 2 or 4 */
+#define PKT_PIPE_FIFO_SIZEW	4 /* total 4 dwords per HSS */
+
+#define RX_DESCS		16 /* also length of all RX queues */
+#define TX_DESCS		16 /* also length of all TX queues */
+
+#define POOL_ALLOC_SIZE		(sizeof(struct desc) * (RX_DESCS + TX_DESCS))
+#define RX_SIZE			(HDLC_MAX_MRU + 4) /* NPE needs more space */
+#define MAX_CLOSE_WAIT		1000 /* microseconds */
+#define HSS_COUNT		2
+#define FRAME_SIZE		256 /* doesn't matter at this point */
+#define FRAME_OFFSET		0
+#define MAX_CHANNELS		(FRAME_SIZE / 8)
+
+#define NAPI_WEIGHT		16
+
+/* Queue IDs */
+#define HSS0_CHL_RXTRIG_QUEUE	12	/* orig size = 32 dwords */
+#define HSS0_PKT_RX_QUEUE	13	/* orig size = 32 dwords */
+#define HSS0_PKT_TX0_QUEUE	14	/* orig size = 16 dwords */
+#define HSS0_PKT_TX1_QUEUE	15
+#define HSS0_PKT_TX2_QUEUE	16
+#define HSS0_PKT_TX3_QUEUE	17
+#define HSS0_PKT_RXFREE0_QUEUE	18	/* orig size = 16 dwords */
+#define HSS0_PKT_RXFREE1_QUEUE	19
+#define HSS0_PKT_RXFREE2_QUEUE	20
+#define HSS0_PKT_RXFREE3_QUEUE	21
+#define HSS0_PKT_TXDONE_QUEUE	22	/* orig size = 64 dwords */
+
+#define HSS1_CHL_RXTRIG_QUEUE	10
+#define HSS1_PKT_RX_QUEUE	0
+#define HSS1_PKT_TX0_QUEUE	5
+#define HSS1_PKT_TX1_QUEUE	6
+#define HSS1_PKT_TX2_QUEUE	7
+#define HSS1_PKT_TX3_QUEUE	8
+#define HSS1_PKT_RXFREE0_QUEUE	1
+#define HSS1_PKT_RXFREE1_QUEUE	2
+#define HSS1_PKT_RXFREE2_QUEUE	3
+#define HSS1_PKT_RXFREE3_QUEUE	4
+#define HSS1_PKT_TXDONE_QUEUE	9
+
+#define NPE_PKT_MODE_HDLC		0
+#define NPE_PKT_MODE_RAW		1
+#define NPE_PKT_MODE_56KMODE		2
+#define NPE_PKT_MODE_56KENDIAN_MSB	4
+
+/* PKT_PIPE_HDLC_CFG_WRITE flags */
+#define PKT_HDLC_IDLE_ONES		0x1 /* default = flags */
+#define PKT_HDLC_CRC_32			0x2 /* default = CRC-16 */
+#define PKT_HDLC_MSB_ENDIAN		0x4 /* default = LE */
+
+
+/* hss_config, PCRs */
+/* Frame sync sampling, default = active low */
+#define PCR_FRM_SYNC_ACTIVE_HIGH	0x40000000
+#define PCR_FRM_SYNC_FALLINGEDGE	0x80000000
+#define PCR_FRM_SYNC_RISINGEDGE		0xC0000000
+
+/* Frame sync pin: input (default) or output generated off a given clk edge */
+#define PCR_FRM_SYNC_OUTPUT_FALLING	0x20000000
+#define PCR_FRM_SYNC_OUTPUT_RISING	0x30000000
+
+/* Frame and data clock sampling on edge, default = falling */
+#define PCR_FCLK_EDGE_RISING		0x08000000
+#define PCR_DCLK_EDGE_RISING		0x04000000
+
+/* Clock direction, default = input */
+#define PCR_SYNC_CLK_DIR_OUTPUT		0x02000000
+
+/* Generate/Receive frame pulses, default = enabled */
+#define PCR_FRM_PULSE_DISABLED		0x01000000
+
+ /* Data rate is full (default) or half the configured clk speed */
+#define PCR_HALF_CLK_RATE		0x00200000
+
+/* Invert data between NPE and HSS FIFOs? (default = no) */
+#define PCR_DATA_POLARITY_INVERT	0x00100000
+
+/* TX/RX endianness, default = LSB */
+#define PCR_MSB_ENDIAN			0x00080000
+
+/* Normal (default) / open drain mode (TX only) */
+#define PCR_TX_PINS_OPEN_DRAIN		0x00040000
+
+/* No framing bit transmitted and expected on RX? (default = framing bit) */
+#define PCR_SOF_NO_FBIT			0x00020000
+
+/* Drive data pins? */
+#define PCR_TX_DATA_ENABLE		0x00010000
+
+/* Voice 56k type: drive the data pins low (default), high, high Z */
+#define PCR_TX_V56K_HIGH		0x00002000
+#define PCR_TX_V56K_HIGH_IMP		0x00004000
+
+/* Unassigned type: drive the data pins low (default), high, high Z */
+#define PCR_TX_UNASS_HIGH		0x00000800
+#define PCR_TX_UNASS_HIGH_IMP		0x00001000
+
+/* T1 @ 1.544MHz only: Fbit dictated in FIFO (default) or high Z */
+#define PCR_TX_FB_HIGH_IMP		0x00000400
+
+/* 56k data endiannes - which bit unused: high (default) or low */
+#define PCR_TX_56KE_BIT_0_UNUSED	0x00000200
+
+/* 56k data transmission type: 32/8 bit data (default) or 56K data */
+#define PCR_TX_56KS_56K_DATA		0x00000100
+
+/* hss_config, cCR */
+/* Number of packetized clients, default = 1 */
+#define CCR_NPE_HFIFO_2_HDLC		0x04000000
+#define CCR_NPE_HFIFO_3_OR_4HDLC	0x08000000
+
+/* default = no loopback */
+#define CCR_LOOPBACK			0x02000000
+
+/* HSS number, default = 0 (first) */
+#define CCR_SECOND_HSS			0x01000000
+
+
+/* hss_config, clkCR: main:10, num:10, denom:12 */
+#define CLK42X_SPEED_EXP	((0x3FF << 22) | (  2 << 12) |   15) /*65 KHz*/
+
+#define CLK42X_SPEED_512KHZ	((  130 << 22) | (  2 << 12) |   15)
+#define CLK42X_SPEED_1536KHZ	((   43 << 22) | ( 18 << 12) |   47)
+#define CLK42X_SPEED_1544KHZ	((   43 << 22) | ( 33 << 12) |  192)
+#define CLK42X_SPEED_2048KHZ	((   32 << 22) | ( 34 << 12) |   63)
+#define CLK42X_SPEED_4096KHZ	((   16 << 22) | ( 34 << 12) |  127)
+#define CLK42X_SPEED_8192KHZ	((    8 << 22) | ( 34 << 12) |  255)
+
+#define CLK46X_SPEED_512KHZ	((  130 << 22) | ( 24 << 12) |  127)
+#define CLK46X_SPEED_1536KHZ	((   43 << 22) | (152 << 12) |  383)
+#define CLK46X_SPEED_1544KHZ	((   43 << 22) | ( 66 << 12) |  385)
+#define CLK46X_SPEED_2048KHZ	((   32 << 22) | (280 << 12) |  511)
+#define CLK46X_SPEED_4096KHZ	((   16 << 22) | (280 << 12) | 1023)
+#define CLK46X_SPEED_8192KHZ	((    8 << 22) | (280 << 12) | 2047)
+
+
+/* hss_config, LUT entries */
+#define TDMMAP_UNASSIGNED	0
+#define TDMMAP_HDLC		1	/* HDLC - packetized */
+#define TDMMAP_VOICE56K		2	/* Voice56K - 7-bit channelized */
+#define TDMMAP_VOICE64K		3	/* Voice64K - 8-bit channelized */
+
+/* offsets into HSS config */
+#define HSS_CONFIG_TX_PCR	0x00 /* port configuration registers */
+#define HSS_CONFIG_RX_PCR	0x04
+#define HSS_CONFIG_CORE_CR	0x08 /* loopback control, HSS# */
+#define HSS_CONFIG_CLOCK_CR	0x0C /* clock generator control */
+#define HSS_CONFIG_TX_FCR	0x10 /* frame configuration registers */
+#define HSS_CONFIG_RX_FCR	0x14
+#define HSS_CONFIG_TX_LUT	0x18 /* channel look-up tables */
+#define HSS_CONFIG_RX_LUT	0x38
+
+
+/* NPE command codes */
+/* writes the ConfigWord value to the location specified by offset */
+#define PORT_CONFIG_WRITE		0x40
+
+/* triggers the NPE to load the contents of the configuration table */
+#define PORT_CONFIG_LOAD		0x41
+
+/* triggers the NPE to return an HssErrorReadResponse message */
+#define PORT_ERROR_READ			0x42
+
+/* triggers the NPE to reset internal status and enable the HssPacketized
+   operation for the flow specified by pPipe */
+#define PKT_PIPE_FLOW_ENABLE		0x50
+#define PKT_PIPE_FLOW_DISABLE		0x51
+#define PKT_NUM_PIPES_WRITE		0x52
+#define PKT_PIPE_FIFO_SIZEW_WRITE	0x53
+#define PKT_PIPE_HDLC_CFG_WRITE		0x54
+#define PKT_PIPE_IDLE_PATTERN_WRITE	0x55
+#define PKT_PIPE_RX_SIZE_WRITE		0x56
+#define PKT_PIPE_MODE_WRITE		0x57
+
+/* HDLC packet status values - desc->status */
+#define ERR_SHUTDOWN		1 /* stop or shutdown occurrance */
+#define ERR_HDLC_ALIGN		2 /* HDLC alignment error */
+#define ERR_HDLC_FCS		3 /* HDLC Frame Check Sum error */
+#define ERR_RXFREE_Q_EMPTY	4 /* RX-free queue became empty while receiving
+				     this packet (if buf_len < pkt_len) */
+#define ERR_HDLC_TOO_LONG	5 /* HDLC frame size too long */
+#define ERR_HDLC_ABORT		6 /* abort sequence received */
+#define ERR_DISCONNECTING	7 /* disconnect is in progress */
+
+
+#ifdef __ARMEB__
+typedef struct sk_buff buffer_t;
+#define free_buffer dev_kfree_skb
+#define free_buffer_irq dev_kfree_skb_irq
+#else
+typedef void buffer_t;
+#define free_buffer kfree
+#define free_buffer_irq kfree
+#endif
+
+struct port {
+	struct device *dev;
+	struct npe *npe;
+	struct net_device *netdev;
+	struct napi_struct napi;
+	struct hss_plat_info *plat;
+	buffer_t *rx_buff_tab[RX_DESCS], *tx_buff_tab[TX_DESCS];
+	struct desc *desc_tab;	/* coherent */
+	u32 desc_tab_phys;
+	unsigned int id;
+	unsigned int clock_type, clock_rate, loopback;
+	unsigned int initialized, carrier;
+	u8 hdlc_cfg;
+};
+
+/* NPE message structure */
+struct msg {
+#ifdef __ARMEB__
+	u8 cmd, unused, hss_port, index;
+	union {
+		struct { u8 data8a, data8b, data8c, data8d; };
+		struct { u16 data16a, data16b; };
+		struct { u32 data32; };
+	};
+#else
+	u8 index, hss_port, unused, cmd;
+	union {
+		struct { u8 data8d, data8c, data8b, data8a; };
+		struct { u16 data16b, data16a; };
+		struct { u32 data32; };
+	};
+#endif
+};
+
+/* HDLC packet descriptor */
+struct desc {
+	u32 next;		/* pointer to next buffer, unused */
+
+#ifdef __ARMEB__
+	u16 buf_len;		/* buffer length */
+	u16 pkt_len;		/* packet length */
+	u32 data;		/* pointer to data buffer in RAM */
+	u8 status;
+	u8 error_count;
+	u16 __reserved;
+#else
+	u16 pkt_len;		/* packet length */
+	u16 buf_len;		/* buffer length */
+	u32 data;		/* pointer to data buffer in RAM */
+	u16 __reserved;
+	u8 error_count;
+	u8 status;
+#endif
+	u32 __reserved1[4];
+};
+
+
+#define rx_desc_phys(port, n)	((port)->desc_tab_phys +		\
+				 (n) * sizeof(struct desc))
+#define rx_desc_ptr(port, n)	(&(port)->desc_tab[n])
+
+#define tx_desc_phys(port, n)	((port)->desc_tab_phys +		\
+				 ((n) + RX_DESCS) * sizeof(struct desc))
+#define tx_desc_ptr(port, n)	(&(port)->desc_tab[(n) + RX_DESCS])
+
+/*****************************************************************************
+ * global variables
+ ****************************************************************************/
+
+static int ports_open;
+static struct dma_pool *dma_pool;
+static spinlock_t npe_lock;
+
+static const struct {
+	int tx, txdone, rx, rxfree;
+}queue_ids[2] = {{HSS0_PKT_TX0_QUEUE, HSS0_PKT_TXDONE_QUEUE, HSS0_PKT_RX_QUEUE,
+		  HSS0_PKT_RXFREE0_QUEUE},
+		 {HSS1_PKT_TX0_QUEUE, HSS1_PKT_TXDONE_QUEUE, HSS1_PKT_RX_QUEUE,
+		  HSS1_PKT_RXFREE0_QUEUE},
+};
+
+/*****************************************************************************
+ * utility functions
+ ****************************************************************************/
+
+static inline struct port* dev_to_port(struct net_device *dev)
+{
+	return dev_to_hdlc(dev)->priv;
+}
+
+#ifndef __ARMEB__
+static inline void memcpy_swab32(u32 *dest, u32 *src, int cnt)
+{
+	int i;
+	for (i = 0; i < cnt; i++)
+		dest[i] = swab32(src[i]);
+}
+#endif
+
+/*****************************************************************************
+ * HSS access
+ ****************************************************************************/
+
+static void hss_npe_send(struct port *port, struct msg *msg, const char* what)
+{
+	u32 *val = (u32*)msg;
+	if (npe_send_message(port->npe, msg, what)) {
+		printk(KERN_CRIT "HSS-%i: unable to send command [%08X:%08X]"
+		       " to %s\n", port->id, val[0], val[1],
+		       npe_name(port->npe));
+		BUG();
+	}
+}
+
+static void hss_config_set_lut(struct port *port)
+{
+	struct msg msg;
+	int ch;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.cmd = PORT_CONFIG_WRITE;
+	msg.hss_port = port->id;
+
+	for (ch = 0; ch < MAX_CHANNELS; ch++) {
+		msg.data32 >>= 2;
+		msg.data32 |= TDMMAP_HDLC << 30;
+
+		if (ch % 16 == 15) {
+			msg.index = HSS_CONFIG_TX_LUT + ((ch / 4) & ~3);
+			hss_npe_send(port, &msg, "HSS_SET_TX_LUT");
+
+			msg.index += HSS_CONFIG_RX_LUT - HSS_CONFIG_TX_LUT;
+			hss_npe_send(port, &msg, "HSS_SET_RX_LUT");
+		}
+	}
+}
+
+static void hss_config(struct port *port)
+{
+	struct msg msg;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.cmd = PORT_CONFIG_WRITE;
+	msg.hss_port = port->id;
+	msg.index = HSS_CONFIG_TX_PCR;
+	msg.data32 = PCR_FRM_SYNC_OUTPUT_RISING | PCR_MSB_ENDIAN |
+		PCR_TX_DATA_ENABLE | PCR_SOF_NO_FBIT;
+	if (port->clock_type == CLOCK_INT)
+		msg.data32 |= PCR_SYNC_CLK_DIR_OUTPUT;
+	hss_npe_send(port, &msg, "HSS_SET_TX_PCR");
+
+	msg.index = HSS_CONFIG_RX_PCR;
+	msg.data32 ^= PCR_TX_DATA_ENABLE | PCR_DCLK_EDGE_RISING;
+	hss_npe_send(port, &msg, "HSS_SET_RX_PCR");
+
+	memset(&msg, 0, sizeof(msg));
+	msg.cmd = PORT_CONFIG_WRITE;
+	msg.hss_port = port->id;
+	msg.index = HSS_CONFIG_CORE_CR;
+	msg.data32 = (port->loopback ? CCR_LOOPBACK : 0) |
+		(port->id ? CCR_SECOND_HSS : 0);
+	hss_npe_send(port, &msg, "HSS_SET_CORE_CR");
+
+	memset(&msg, 0, sizeof(msg));
+	msg.cmd = PORT_CONFIG_WRITE;
+	msg.hss_port = port->id;
+	msg.index = HSS_CONFIG_CLOCK_CR;
+	msg.data32 = CLK42X_SPEED_2048KHZ /* FIXME */;
+	hss_npe_send(port, &msg, "HSS_SET_CLOCK_CR");
+
+	memset(&msg, 0, sizeof(msg));
+	msg.cmd = PORT_CONFIG_WRITE;
+	msg.hss_port = port->id;
+	msg.index = HSS_CONFIG_TX_FCR;
+	msg.data16a = FRAME_OFFSET;
+	msg.data16b = FRAME_SIZE - 1;
+	hss_npe_send(port, &msg, "HSS_SET_TX_FCR");
+
+	memset(&msg, 0, sizeof(msg));
+	msg.cmd = PORT_CONFIG_WRITE;
+	msg.hss_port = port->id;
+	msg.index = HSS_CONFIG_RX_FCR;
+	msg.data16a = FRAME_OFFSET;
+	msg.data16b = FRAME_SIZE - 1;
+	hss_npe_send(port, &msg, "HSS_SET_RX_FCR");
+
+	hss_config_set_lut(port);
+
+	memset(&msg, 0, sizeof(msg));
+	msg.cmd = PORT_CONFIG_LOAD;
+	msg.hss_port = port->id;
+	hss_npe_send(port, &msg, "HSS_LOAD_CONFIG");
+
+	if (npe_recv_message(port->npe, &msg, "HSS_LOAD_CONFIG") ||
+	    /* HSS_LOAD_CONFIG for port #1 returns port_id = #4 */
+	    msg.cmd != PORT_CONFIG_LOAD || msg.data32) {
+		printk(KERN_CRIT "HSS-%i: HSS_LOAD_CONFIG failed\n",
+		       port->id);
+		BUG();
+	}
+
+	/* HDLC may stop working without this - check FIXME */
+	npe_recv_message(port->npe, &msg, "FLUSH_IT");
+}
+
+static void hss_set_hdlc_cfg(struct port *port)
+{
+	struct msg msg;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.cmd = PKT_PIPE_HDLC_CFG_WRITE;
+	msg.hss_port = port->id;
+	msg.data8a = port->hdlc_cfg; /* rx_cfg */
+	msg.data8b = port->hdlc_cfg | (PKT_EXTRA_FLAGS << 3); /* tx_cfg */
+	hss_npe_send(port, &msg, "HSS_SET_HDLC_CFG");
+}
+
+static u32 hss_get_status(struct port *port)
+{
+	struct msg msg;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.cmd = PORT_ERROR_READ;
+	msg.hss_port = port->id;
+	hss_npe_send(port, &msg, "PORT_ERROR_READ");
+	if (npe_recv_message(port->npe, &msg, "PORT_ERROR_READ")) {
+		printk(KERN_CRIT "HSS-%i: unable to read HSS status\n",
+		       port->id);
+		BUG();
+	}
+
+	return msg.data32;
+}
+
+static void hss_start_hdlc(struct port *port)
+{
+	struct msg msg;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.cmd = PKT_PIPE_FLOW_ENABLE;
+	msg.hss_port = port->id;
+	msg.data32 = 0;
+	hss_npe_send(port, &msg, "HSS_ENABLE_PKT_PIPE");
+}
+
+static void hss_stop_hdlc(struct port *port)
+{
+	struct msg msg;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.cmd = PKT_PIPE_FLOW_DISABLE;
+	msg.hss_port = port->id;
+	hss_npe_send(port, &msg, "HSS_DISABLE_PKT_PIPE");
+	hss_get_status(port); /* make sure it's halted */
+}
+
+static int hss_load_firmware(struct port *port)
+{
+	struct msg msg;
+	int err;
+
+	if (port->initialized)
+		return 0;
+
+	if (!npe_running(port->npe) &&
+	    (err = npe_load_firmware(port->npe, npe_name(port->npe),
+				     port->dev)))
+		return err;
+
+	/* HDLC mode configuration */
+	memset(&msg, 0, sizeof(msg));
+	msg.cmd = PKT_NUM_PIPES_WRITE;
+	msg.hss_port = port->id;
+	msg.data8a = PKT_NUM_PIPES;
+	hss_npe_send(port, &msg, "HSS_SET_PKT_PIPES");
+
+	msg.cmd = PKT_PIPE_FIFO_SIZEW_WRITE;
+	msg.data8a = PKT_PIPE_FIFO_SIZEW;
+	hss_npe_send(port, &msg, "HSS_SET_PKT_FIFO");
+
+	msg.cmd = PKT_PIPE_MODE_WRITE;
+	msg.data8a = NPE_PKT_MODE_HDLC;
+	/* msg.data8b = inv_mask */
+	/* msg.data8c = or_mask */
+	hss_npe_send(port, &msg, "HSS_SET_PKT_MODE");
+
+	msg.cmd = PKT_PIPE_RX_SIZE_WRITE;
+	msg.data16a = HDLC_MAX_MRU; /* including CRC */
+	hss_npe_send(port, &msg, "HSS_SET_PKT_RX_SIZE");
+
+	msg.cmd = PKT_PIPE_IDLE_PATTERN_WRITE;
+	msg.data32 = 0x7F7F7F7F; /* ??? FIXME */
+	hss_npe_send(port, &msg, "HSS_SET_PKT_IDLE");
+
+	port->initialized = 1;
+	return 0;
+}
+
+/*****************************************************************************
+ * packetized (HDLC) operation
+ ****************************************************************************/
+
+static inline void debug_pkt(struct net_device *dev, const char *func,
+			     u8 *data, int len)
+{
+#if DEBUG_PKT_BYTES
+	int i;
+
+	printk(KERN_DEBUG "%s: %s(%i)", dev->name, func, len);
+	for (i = 0; i < len; i++) {
+		if (i >= DEBUG_PKT_BYTES)
+			break;
+		printk("%s%02X", !(i % 4) ? " " : "", data[i]);
+	}
+	printk("\n");
+#endif
+}
+
+
+static inline void debug_desc(u32 phys, struct desc *desc)
+{
+#if DEBUG_DESC
+	printk(KERN_DEBUG "%X: %X %3X %3X %08X %X %X\n",
+	       phys, desc->next, desc->buf_len, desc->pkt_len,
+	       desc->data, desc->status, desc->error_count);
+#endif
+}
+
+static inline void debug_queue(unsigned int queue, int is_get, u32 phys)
+{
+#if DEBUG_QUEUES
+	static struct {
+		int queue;
+		char *name;
+	} names[] = {
+		{ HSS0_PKT_TX0_QUEUE, "TX#0 " },
+		{ HSS0_PKT_TXDONE_QUEUE, "TX-done#0 " },
+		{ HSS0_PKT_RX_QUEUE, "RX#0 " },
+		{ HSS0_PKT_RXFREE0_QUEUE, "RX-free#0 " },
+		{ HSS1_PKT_TX0_QUEUE, "TX#1 " },
+		{ HSS1_PKT_TXDONE_QUEUE, "TX-done#1 " },
+		{ HSS1_PKT_RX_QUEUE, "RX#1 " },
+		{ HSS1_PKT_RXFREE0_QUEUE, "RX-free#1 " },
+	};
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(names); i++)
+		if (names[i].queue == queue)
+			break;
+
+	printk(KERN_DEBUG "Queue %i %s%s %X\n", queue,
+	       i < ARRAY_SIZE(names) ? names[i].name : "",
+	       is_get ? "->" : "<-", phys);
+#endif
+}
+
+static inline u32 queue_get_entry(unsigned int queue)
+{
+	u32 phys = qmgr_get_entry(queue);
+	debug_queue(queue, 1, phys);
+	return phys;
+}
+
+static inline int queue_get_desc(unsigned int queue, struct port *port,
+				 int is_tx)
+{
+	u32 phys, tab_phys, n_desc;
+	struct desc *tab;
+
+	if (!(phys = queue_get_entry(queue)))
+		return -1;
+
+	BUG_ON(phys & 0x1F);
+	tab_phys = is_tx ? tx_desc_phys(port, 0) : rx_desc_phys(port, 0);
+	tab = is_tx ? tx_desc_ptr(port, 0) : rx_desc_ptr(port, 0);
+	n_desc = (phys - tab_phys) / sizeof(struct desc);
+	BUG_ON(n_desc >= (is_tx ? TX_DESCS : RX_DESCS));
+	debug_desc(phys, &tab[n_desc]);
+	BUG_ON(tab[n_desc].next);
+	return n_desc;
+}
+
+static inline void queue_put_desc(unsigned int queue, u32 phys,
+				  struct desc *desc)
+{
+	debug_queue(queue, 0, phys);
+	debug_desc(phys, desc);
+	BUG_ON(phys & 0x1F);
+	qmgr_put_entry(queue, phys);
+	BUG_ON(qmgr_stat_overflow(queue));
+}
+
+
+static inline void dma_unmap_tx(struct port *port, struct desc *desc)
+{
+#ifdef __ARMEB__
+	dma_unmap_single(&port->netdev->dev, desc->data,
+			 desc->buf_len, DMA_TO_DEVICE);
+#else
+	dma_unmap_single(&port->netdev->dev, desc->data & ~3,
+			 ALIGN((desc->data & 3) + desc->buf_len, 4),
+			 DMA_TO_DEVICE);
+#endif
+}
+
+
+static void hss_hdlc_set_carrier(void *pdev, int carrier)
+{
+	struct net_device *netdev = pdev;
+	struct port *port = dev_to_port(netdev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&npe_lock, flags);
+	port->carrier = carrier;
+	if (!port->loopback) {
+		if (carrier)
+			netif_carrier_on(netdev);
+		else
+			netif_carrier_off(netdev);
+	}
+	spin_unlock_irqrestore(&npe_lock, flags);
+}
+
+static void hss_hdlc_rx_irq(void *pdev)
+{
+	struct net_device *dev = pdev;
+	struct port *port = dev_to_port(dev);
+
+#if DEBUG_RX
+	printk(KERN_DEBUG "%s: hss_hdlc_rx_irq\n", dev->name);
+#endif
+	qmgr_disable_irq(queue_ids[port->id].rx);
+	netif_rx_schedule(dev, &port->napi);
+}
+
+static int hss_hdlc_poll(struct napi_struct *napi, int budget)
+{
+	struct port *port = container_of(napi, struct port, napi);
+	struct net_device *dev = port->netdev;
+	unsigned int rxq = queue_ids[port->id].rx;
+	unsigned int rxfreeq = queue_ids[port->id].rxfree;
+	int received = 0;
+
+#if DEBUG_RX
+	printk(KERN_DEBUG "%s: hss_hdlc_poll\n", dev->name);
+#endif
+
+	while (received < budget) {
+		struct sk_buff *skb;
+		struct desc *desc;
+		int n;
+#ifdef __ARMEB__
+		struct sk_buff *temp;
+		u32 phys;
+#endif
+
+		if ((n = queue_get_desc(rxq, port, 0)) < 0) {
+#if DEBUG_RX
+			printk(KERN_DEBUG "%s: hss_hdlc_poll"
+			       " netif_rx_complete\n", dev->name);
+#endif
+			netif_rx_complete(dev, napi);
+			qmgr_enable_irq(rxq);
+			if (!qmgr_stat_empty(rxq) &&
+			    netif_rx_reschedule(dev, napi)) {
+#if DEBUG_RX
+				printk(KERN_DEBUG "%s: hss_hdlc_poll"
+				       " netif_rx_reschedule succeeded\n",
+				       dev->name);
+#endif
+				qmgr_disable_irq(rxq);
+				continue;
+			}
+#if DEBUG_RX
+			printk(KERN_DEBUG "%s: hss_hdlc_poll all done\n",
+			       dev->name);
+#endif
+			return received; /* all work done */
+		}
+
+		desc = rx_desc_ptr(port, n);
+#if 0 /* FIXME - error_count counts modulo 256, perhaps we should use it */
+		if (desc->error_count)
+			printk(KERN_DEBUG "%s: hss_hdlc_poll status 0x%02X"
+			       " errors %u\n", dev->name, desc->status,
+			       desc->error_count);
+#endif
+		skb = NULL;
+		switch (desc->status) {
+		case 0:
+#ifdef __ARMEB__
+			if ((skb = netdev_alloc_skb(dev, RX_SIZE)) != NULL) {
+				phys = dma_map_single(&dev->dev, skb->data,
+						      RX_SIZE,
+						      DMA_FROM_DEVICE);
+				if (dma_mapping_error(&dev->dev, phys)) {
+					dev_kfree_skb(skb);
+					skb = NULL;
+				}
+			}
+#else
+			skb = netdev_alloc_skb(dev, desc->pkt_len);
+#endif
+			if (!skb)
+				dev->stats.rx_dropped++;
+			break;
+		case ERR_HDLC_ALIGN:
+		case ERR_HDLC_ABORT:
+			dev->stats.rx_frame_errors++;
+			dev->stats.rx_errors++;
+			break;
+		case ERR_HDLC_FCS:
+			dev->stats.rx_crc_errors++;
+			dev->stats.rx_errors++;
+			break;
+		case ERR_HDLC_TOO_LONG:
+			dev->stats.rx_length_errors++;
+			dev->stats.rx_errors++;
+			break;
+		default:	/* FIXME - remove printk */
+			printk(KERN_ERR "%s: hss_hdlc_poll: status 0x%02X"
+			       " errors %u\n", dev->name, desc->status,
+			       desc->error_count);
+			dev->stats.rx_errors++;
+		}
+
+		if (!skb) {
+			/* put the desc back on RX-ready queue */
+			desc->buf_len = RX_SIZE;
+			desc->pkt_len = desc->status = 0;
+			queue_put_desc(rxfreeq, rx_desc_phys(port, n), desc);
+			continue;
+		}
+
+		/* process received frame */
+#ifdef __ARMEB__
+		temp = skb;
+		skb = port->rx_buff_tab[n];
+		dma_unmap_single(&dev->dev, desc->data,
+				 RX_SIZE, DMA_FROM_DEVICE);
+#else
+		dma_sync_single(&dev->dev, desc->data,
+				RX_SIZE, DMA_FROM_DEVICE);
+		memcpy_swab32((u32 *)skb->data, (u32 *)port->rx_buff_tab[n],
+			      ALIGN(desc->pkt_len, 4) / 4);
+#endif
+		skb_put(skb, desc->pkt_len);
+
+		debug_pkt(dev, "hss_hdlc_poll", skb->data, skb->len);
+
+		skb->protocol = hdlc_type_trans(skb, dev);
+		dev->stats.rx_packets++;
+		dev->stats.rx_bytes += skb->len;
+		netif_receive_skb(skb);
+
+		/* put the new buffer on RX-free queue */
+#ifdef __ARMEB__
+		port->rx_buff_tab[n] = temp;
+		desc->data = phys;
+#endif
+		desc->buf_len = RX_SIZE;
+		desc->pkt_len = 0;
+		queue_put_desc(rxfreeq, rx_desc_phys(port, n), desc);
+		received++;
+	}
+#if DEBUG_RX
+	printk(KERN_DEBUG "hss_hdlc_poll: end, not all work done\n");
+#endif
+	return received;	/* not all work done */
+}
+
+
+static void hss_hdlc_txdone_irq(void *pdev)
+{
+	struct net_device *dev = pdev;
+	struct port *port = dev_to_port(dev);
+	int n_desc;
+
+#if DEBUG_TX
+	printk(KERN_DEBUG DRV_NAME ": hss_hdlc_txdone_irq\n");
+#endif
+	while ((n_desc = queue_get_desc(queue_ids[port->id].txdone,
+					port, 1)) >= 0) {
+		struct desc *desc;
+		int start;
+
+		desc = tx_desc_ptr(port, n_desc);
+
+		dev->stats.tx_packets++;
+		dev->stats.tx_bytes += desc->pkt_len;
+
+		dma_unmap_tx(port, desc);
+#if DEBUG_TX
+		printk(KERN_DEBUG "%s: hss_hdlc_txdone_irq free %p\n",
+		       dev->name, port->tx_buff_tab[n_desc]);
+#endif
+		free_buffer_irq(port->tx_buff_tab[n_desc]);
+		port->tx_buff_tab[n_desc] = NULL;
+
+		start = qmgr_stat_empty(port->plat->txreadyq);
+		queue_put_desc(port->plat->txreadyq,
+			       tx_desc_phys(port, n_desc), desc);
+		if (start) {
+#if DEBUG_TX
+			printk(KERN_DEBUG "%s: hss_hdlc_txdone_irq xmit"
+			       " ready\n", dev->name);
+#endif
+			netif_wake_queue(dev);
+		}
+	}
+}
+
+static int hss_hdlc_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct port *port = dev_to_port(dev);
+	unsigned int txreadyq = port->plat->txreadyq;
+	int len, offset, bytes, n;
+	void *mem;
+	u32 phys;
+	struct desc *desc;
+
+#if DEBUG_TX
+	printk(KERN_DEBUG "%s: hss_hdlc_xmit\n", dev->name);
+#endif
+
+	if (unlikely(skb->len > HDLC_MAX_MRU)) {
+		dev_kfree_skb(skb);
+		dev->stats.tx_errors++;
+		return NETDEV_TX_OK;
+	}
+
+	debug_pkt(dev, "hss_hdlc_xmit", skb->data, skb->len);
+
+	len = skb->len;
+#ifdef __ARMEB__
+	offset = 0; /* no need to keep alignment */
+	bytes = len;
+	mem = skb->data;
+#else
+	offset = (int)skb->data & 3; /* keep 32-bit alignment */
+	bytes = ALIGN(offset + len, 4);
+	if (!(mem = kmalloc(bytes, GFP_ATOMIC))) {
+		dev_kfree_skb(skb);
+		dev->stats.tx_dropped++;
+		return NETDEV_TX_OK;
+	}
+	memcpy_swab32(mem, (u32 *)((int)skb->data & ~3), bytes / 4);
+	dev_kfree_skb(skb);
+#endif
+
+	phys = dma_map_single(&dev->dev, mem, bytes, DMA_TO_DEVICE);
+	if (dma_mapping_error(&dev->dev, phys)) {
+#ifdef __ARMEB__
+		dev_kfree_skb(skb);
+#else
+		kfree(mem);
+#endif
+		dev->stats.tx_dropped++;
+		return NETDEV_TX_OK;
+	}
+
+	n = queue_get_desc(txreadyq, port, 1);
+	BUG_ON(n < 0);
+	desc = tx_desc_ptr(port, n);
+
+#ifdef __ARMEB__
+	port->tx_buff_tab[n] = skb;
+#else
+	port->tx_buff_tab[n] = mem;
+#endif
+	desc->data = phys + offset;
+	desc->buf_len = desc->pkt_len = len;
+
+	wmb();
+	queue_put_desc(queue_ids[port->id].tx, tx_desc_phys(port, n), desc);
+	dev->trans_start = jiffies;
+
+	if (qmgr_stat_empty(txreadyq)) {
+#if DEBUG_TX
+		printk(KERN_DEBUG "%s: hss_hdlc_xmit queue full\n", dev->name);
+#endif
+		netif_stop_queue(dev);
+		/* we could miss TX ready interrupt */
+		if (!qmgr_stat_empty(txreadyq)) {
+#if DEBUG_TX
+			printk(KERN_DEBUG "%s: hss_hdlc_xmit ready again\n",
+			       dev->name);
+#endif
+			netif_wake_queue(dev);
+		}
+	}
+
+#if DEBUG_TX
+	printk(KERN_DEBUG "%s: hss_hdlc_xmit end\n", dev->name);
+#endif
+	return NETDEV_TX_OK;
+}
+
+
+static int request_hdlc_queues(struct port *port)
+{
+	int err;
+
+	err = qmgr_request_queue(queue_ids[port->id].rxfree, RX_DESCS, 0, 0);
+	if (err)
+		return err;
+
+	err = qmgr_request_queue(queue_ids[port->id].rx, RX_DESCS, 0, 0);
+	if (err)
+		goto rel_rxfree;
+
+	err = qmgr_request_queue(queue_ids[port->id].tx, TX_DESCS, 0, 0);
+	if (err)
+		goto rel_rx;
+
+	err = qmgr_request_queue(port->plat->txreadyq, TX_DESCS, 0, 0);
+	if (err)
+		goto rel_tx;
+
+	err = qmgr_request_queue(queue_ids[port->id].txdone, TX_DESCS, 0, 0);
+	if (err)
+		goto rel_txready;
+	return 0;
+
+rel_txready:
+	qmgr_release_queue(port->plat->txreadyq);
+rel_tx:
+	qmgr_release_queue(queue_ids[port->id].tx);
+rel_rx:
+	qmgr_release_queue(queue_ids[port->id].rx);
+rel_rxfree:
+	qmgr_release_queue(queue_ids[port->id].rxfree);
+	printk(KERN_DEBUG "%s: unable to request hardware queues\n",
+	       port->netdev->name);
+	return err;
+}
+
+static void release_hdlc_queues(struct port *port)
+{
+	qmgr_release_queue(queue_ids[port->id].rxfree);
+	qmgr_release_queue(queue_ids[port->id].rx);
+	qmgr_release_queue(queue_ids[port->id].txdone);
+	qmgr_release_queue(queue_ids[port->id].tx);
+	qmgr_release_queue(port->plat->txreadyq);
+}
+
+static int init_hdlc_queues(struct port *port)
+{
+	int i;
+
+	if (!ports_open)
+		if (!(dma_pool = dma_pool_create(DRV_NAME, NULL,
+						 POOL_ALLOC_SIZE, 32, 0)))
+			return -ENOMEM;
+
+	if (!(port->desc_tab = dma_pool_alloc(dma_pool, GFP_KERNEL,
+					      &port->desc_tab_phys)))
+		return -ENOMEM;
+	memset(port->desc_tab, 0, POOL_ALLOC_SIZE);
+	memset(port->rx_buff_tab, 0, sizeof(port->rx_buff_tab)); /* tables */
+	memset(port->tx_buff_tab, 0, sizeof(port->tx_buff_tab));
+
+	/* Setup RX buffers */
+	for (i = 0; i < RX_DESCS; i++) {
+		struct desc *desc = rx_desc_ptr(port, i);
+		buffer_t *buff;
+		void *data;
+#ifdef __ARMEB__
+		if (!(buff = netdev_alloc_skb(port->netdev, RX_SIZE)))
+			return -ENOMEM;
+		data = buff->data;
+#else
+		if (!(buff = kmalloc(RX_SIZE, GFP_KERNEL)))
+			return -ENOMEM;
+		data = buff;
+#endif
+		desc->buf_len = RX_SIZE;
+		desc->data = dma_map_single(&port->netdev->dev, data,
+					    RX_SIZE, DMA_FROM_DEVICE);
+		if (dma_mapping_error(&port->netdev->dev, desc->data)) {
+			free_buffer(buff);
+			return -EIO;
+		}
+		port->rx_buff_tab[i] = buff;
+	}
+
+	return 0;
+}
+
+static void destroy_hdlc_queues(struct port *port)
+{
+	int i;
+
+	if (port->desc_tab) {
+		for (i = 0; i < RX_DESCS; i++) {
+			struct desc *desc = rx_desc_ptr(port, i);
+			buffer_t *buff = port->rx_buff_tab[i];
+			if (buff) {
+				dma_unmap_single(&port->netdev->dev,
+						 desc->data, RX_SIZE,
+						 DMA_FROM_DEVICE);
+				free_buffer(buff);
+			}
+		}
+		for (i = 0; i < TX_DESCS; i++) {
+			struct desc *desc = tx_desc_ptr(port, i);
+			buffer_t *buff = port->tx_buff_tab[i];
+			if (buff) {
+				dma_unmap_tx(port, desc);
+				free_buffer(buff);
+			}
+		}
+		dma_pool_free(dma_pool, port->desc_tab, port->desc_tab_phys);
+		port->desc_tab = NULL;
+	}
+
+	if (!ports_open && dma_pool) {
+		dma_pool_destroy(dma_pool);
+		dma_pool = NULL;
+	}
+}
+
+static int hss_hdlc_open(struct net_device *dev)
+{
+	struct port *port = dev_to_port(dev);
+	unsigned long flags;
+	int i, err = 0;
+
+	if ((err = hdlc_open(dev)))
+		return err;
+
+	if ((err = hss_load_firmware(port)))
+		goto err_hdlc_close;
+
+	if ((err = request_hdlc_queues(port)))
+		goto err_hdlc_close;
+
+	if ((err = init_hdlc_queues(port)))
+		goto err_destroy_queues;
+
+	spin_lock_irqsave(&npe_lock, flags);
+	if (port->plat->open)
+		if ((err = port->plat->open(port->id, dev,
+					    hss_hdlc_set_carrier)))
+			goto err_unlock;
+	spin_unlock_irqrestore(&npe_lock, flags);
+
+	/* Populate queues with buffers, no failure after this point */
+	for (i = 0; i < TX_DESCS; i++)
+		queue_put_desc(port->plat->txreadyq,
+			       tx_desc_phys(port, i), tx_desc_ptr(port, i));
+
+	for (i = 0; i < RX_DESCS; i++)
+		queue_put_desc(queue_ids[port->id].rxfree,
+			       rx_desc_phys(port, i), rx_desc_ptr(port, i));
+
+	napi_enable(&port->napi);
+	netif_start_queue(dev);
+
+	qmgr_set_irq(queue_ids[port->id].rx, QUEUE_IRQ_SRC_NOT_EMPTY,
+		     hss_hdlc_rx_irq, dev);
+
+	qmgr_set_irq(queue_ids[port->id].txdone, QUEUE_IRQ_SRC_NOT_EMPTY,
+		     hss_hdlc_txdone_irq, dev);
+	qmgr_enable_irq(queue_ids[port->id].txdone);
+
+	ports_open++;
+
+	hss_set_hdlc_cfg(port);
+	hss_config(port);
+
+	hss_start_hdlc(port);
+
+	/* we may already have RX data, enables IRQ */
+	netif_rx_schedule(dev, &port->napi);
+	return 0;
+
+err_unlock:
+	spin_unlock_irqrestore(&npe_lock, flags);
+err_destroy_queues:
+	destroy_hdlc_queues(port);
+	release_hdlc_queues(port);
+err_hdlc_close:
+	hdlc_close(dev);
+	return err;
+}
+
+static int hss_hdlc_close(struct net_device *dev)
+{
+	struct port *port = dev_to_port(dev);
+	unsigned long flags;
+	int i, buffs = RX_DESCS; /* allocated RX buffers */
+
+	spin_lock_irqsave(&npe_lock, flags);
+	ports_open--;
+	qmgr_disable_irq(queue_ids[port->id].rx);
+	netif_stop_queue(dev);
+	napi_disable(&port->napi);
+
+	hss_stop_hdlc(port);
+
+	while (queue_get_desc(queue_ids[port->id].rxfree, port, 0) >= 0)
+		buffs--;
+	while (queue_get_desc(queue_ids[port->id].rx, port, 0) >= 0)
+		buffs--;
+
+	if (buffs)
+		printk(KERN_CRIT "%s: unable to drain RX queue, %i buffer(s)"
+		       " left in NPE\n", dev->name, buffs);
+
+	buffs = TX_DESCS;
+	while (queue_get_desc(queue_ids[port->id].tx, port, 1) >= 0)
+		buffs--; /* cancel TX */
+
+	i = 0;
+	do {
+		while (queue_get_desc(port->plat->txreadyq, port, 1) >= 0)
+			buffs--;
+		if (!buffs)
+			break;
+	} while (++i < MAX_CLOSE_WAIT);
+
+	if (buffs)
+		printk(KERN_CRIT "%s: unable to drain TX queue, %i buffer(s) "
+		       "left in NPE\n", dev->name, buffs);
+#if DEBUG_CLOSE
+	if (!buffs)
+		printk(KERN_DEBUG "Draining TX queues took %i cycles\n", i);
+#endif
+	qmgr_disable_irq(queue_ids[port->id].txdone);
+
+	if (port->plat->close)
+		port->plat->close(port->id, dev);
+	spin_unlock_irqrestore(&npe_lock, flags);
+
+	destroy_hdlc_queues(port);
+	release_hdlc_queues(port);
+	hdlc_close(dev);
+	return 0;
+}
+
+
+static int hss_hdlc_attach(struct net_device *dev, unsigned short encoding,
+			   unsigned short parity)
+{
+	struct port *port = dev_to_port(dev);
+
+	if (encoding != ENCODING_NRZ)
+		return -EINVAL;
+
+	switch(parity) {
+	case PARITY_CRC16_PR1_CCITT:
+		port->hdlc_cfg = 0;
+		return 0;
+
+	case PARITY_CRC32_PR1_CCITT:
+		port->hdlc_cfg = PKT_HDLC_CRC_32;
+		return 0;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+
+static int hss_hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+	const size_t size = sizeof(sync_serial_settings);
+	sync_serial_settings new_line;
+	sync_serial_settings __user *line = ifr->ifr_settings.ifs_ifsu.sync;
+	struct port *port = dev_to_port(dev);
+	unsigned long flags;
+	int clk;
+
+	if (cmd != SIOCWANDEV)
+		return hdlc_ioctl(dev, ifr, cmd);
+
+	switch(ifr->ifr_settings.type) {
+	case IF_GET_IFACE:
+		ifr->ifr_settings.type = IF_IFACE_V35;
+		if (ifr->ifr_settings.size < size) {
+			ifr->ifr_settings.size = size; /* data size wanted */
+			return -ENOBUFS;
+		}
+		memset(&new_line, 0, sizeof(new_line));
+		new_line.clock_type = port->clock_type;
+		new_line.clock_rate = 2048000; /* FIXME */
+		new_line.loopback = port->loopback;
+		if (copy_to_user(line, &new_line, size))
+			return -EFAULT;
+		return 0;
+
+	case IF_IFACE_SYNC_SERIAL:
+	case IF_IFACE_V35:
+		if(!capable(CAP_NET_ADMIN))
+			return -EPERM;
+		if (copy_from_user(&new_line, line, size))
+			return -EFAULT;
+
+		clk = new_line.clock_type;
+		if (port->plat->set_clock)
+			clk = port->plat->set_clock(port->id, clk);
+
+		if (clk != CLOCK_EXT && clk != CLOCK_INT)
+			return -EINVAL;	/* No such clock setting */
+
+		if (new_line.loopback != 0 && new_line.loopback != 1)
+			return -EINVAL;
+
+		port->clock_type = clk; /* Update settings */
+		/* FIXME port->clock_rate = new_line.clock_rate */;
+		port->loopback = new_line.loopback;
+
+		spin_lock_irqsave(&npe_lock, flags);
+
+		if (dev->flags & IFF_UP)
+			hss_config(port);
+
+		if (port->loopback || port->carrier)
+			netif_carrier_on(port->netdev);
+		else
+			netif_carrier_off(port->netdev);
+		spin_unlock_irqrestore(&npe_lock, flags);
+
+		return 0;
+
+	default:
+		return hdlc_ioctl(dev, ifr, cmd);
+	}
+}
+
+/*****************************************************************************
+ * initialization
+ ****************************************************************************/
+
+static int __devinit hss_init_one(struct platform_device *pdev)
+{
+	struct port *port;
+	struct net_device *dev;
+	hdlc_device *hdlc;
+	int err;
+
+	if ((port = kzalloc(sizeof(*port), GFP_KERNEL)) == NULL)
+		return -ENOMEM;
+
+	if ((port->npe = npe_request(0)) == NULL) {
+		err = -ENOSYS;
+		goto err_free;
+	}
+
+	if ((port->netdev = dev = alloc_hdlcdev(port)) == NULL) {
+		err = -ENOMEM;
+		goto err_plat;
+	}
+
+	SET_NETDEV_DEV(dev, &pdev->dev);
+	hdlc = dev_to_hdlc(dev);
+	hdlc->attach = hss_hdlc_attach;
+	hdlc->xmit = hss_hdlc_xmit;
+	dev->open = hss_hdlc_open;
+	dev->stop = hss_hdlc_close;
+	dev->do_ioctl = hss_hdlc_ioctl;
+	dev->tx_queue_len = 100;
+	port->clock_type = CLOCK_EXT;
+	port->clock_rate = 2048000;
+	port->id = pdev->id;
+	port->dev = &pdev->dev;
+	port->plat = pdev->dev.platform_data;
+	netif_napi_add(dev, &port->napi, hss_hdlc_poll, NAPI_WEIGHT);
+
+	if ((err = register_hdlc_device(dev)))
+		goto err_free_netdev;
+
+	platform_set_drvdata(pdev, port);
+
+	printk(KERN_INFO "%s: HSS-%i\n", dev->name, port->id);
+	return 0;
+
+err_free_netdev:
+	free_netdev(dev);
+err_plat:
+	npe_release(port->npe);
+err_free:
+	kfree(port);
+	return err;
+}
+
+static int __devexit hss_remove_one(struct platform_device *pdev)
+{
+	struct port *port = platform_get_drvdata(pdev);
+
+	unregister_hdlc_device(port->netdev);
+	free_netdev(port->netdev);
+	npe_release(port->npe);
+	platform_set_drvdata(pdev, NULL);
+	kfree(port);
+	return 0;
+}
+
+static struct platform_driver ixp4xx_hss_driver = {
+	.driver.name	= DRV_NAME,
+	.probe		= hss_init_one,
+	.remove		= hss_remove_one,
+};
+
+static int __init hss_init_module(void)
+{
+	if ((ixp4xx_read_feature_bits() &
+	     (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS)) !=
+	    (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS))
+		return -ENOSYS;
+
+	spin_lock_init(&npe_lock);
+
+	return platform_driver_register(&ixp4xx_hss_driver);
+}
+
+static void __exit hss_cleanup_module(void)
+{
+	platform_driver_unregister(&ixp4xx_hss_driver);
+}
+
+MODULE_AUTHOR("Krzysztof Halasa");
+MODULE_DESCRIPTION("Intel IXP4xx HSS driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:ixp4xx_hss");
+module_init(hss_init_module);
+module_exit(hss_cleanup_module);