Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1545 insertions, 0 deletions

diff --git a/drivers/net/wan/ixp4xx_hss.c b/drivers/net/wan/ixp4xx_hss.c
new file mode 100644
index 000000000..e46b7f5ee
--- /dev/null
+++ b/drivers/net/wan/ixp4xx_hss.c
@@ -0,0 +1,1545 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel IXP4xx HSS (synchronous serial port) driver for Linux
+ *
+ * Copyright (C) 2007-2008 Krzysztof Hałasa <khc@pm.waw.pl>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#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/mfd/syscon.h>
+#include <linux/platform_device.h>
+#include <linux/poll.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/gpio/consumer.h>
+#include <linux/of.h>
+#include <linux/soc/ixp4xx/npe.h>
+#include <linux/soc/ixp4xx/qmgr.h>
+#include <linux/soc/ixp4xx/cpu.h>
+
+/* This is what all IXP4xx platforms we know uses, if more frequencies
+ * are needed, we need to migrate to the clock framework.
+ */
+#define IXP4XX_TIMER_FREQ	66666000
+
+#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_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_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_CLOCK_CR register consists of 3 parts:
+ *     A (10 bits), B (10 bits) and C (12 bits).
+ * IXP42x HSS clock generator operation (verified with an oscilloscope):
+ * Each clock bit takes 7.5 ns (1 / 133.xx MHz).
+ * The clock sequence consists of (C - B) states of 0s and 1s, each state is
+ * A bits wide. It's followed by (B + 1) states of 0s and 1s, each state is
+ * (A + 1) bits wide.
+ *
+ * The resulting average clock frequency (assuming 33.333 MHz oscillator) is:
+ * freq = 66.666 MHz / (A + (B + 1) / (C + 1))
+ * minimum freq = 66.666 MHz / (A + 1)
+ * maximum freq = 66.666 MHz / A
+ *
+ * Example: A = 2, B = 2, C = 7, CLOCK_CR register = 2 << 22 | 2 << 12 | 7
+ * freq = 66.666 MHz / (2 + (2 + 1) / (7 + 1)) = 28.07 MHz (Mb/s).
+ * The clock sequence is: 1100110011 (5 doubles) 000111000 (3 triples).
+ * The sequence takes (C - B) * A + (B + 1) * (A + 1) = 5 * 2 + 3 * 3 bits
+ * = 19 bits (each 7.5 ns long) = 142.5 ns (then the sequence repeats).
+ * The sequence consists of 4 complete clock periods, thus the average
+ * frequency (= clock rate) is 4 / 142.5 ns = 28.07 MHz (Mb/s).
+ * (max specified clock rate for IXP42x HSS is 8.192 Mb/s).
+ */
+
+/* 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 occurrence */
+#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_consume_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;
+	unsigned int txreadyq;
+	unsigned int rxtrigq;
+	unsigned int rxfreeq;
+	unsigned int rxq;
+	unsigned int txq;
+	unsigned int txdoneq;
+	struct gpio_desc *cts;
+	struct gpio_desc *rts;
+	struct gpio_desc *dcd;
+	struct gpio_desc *dtr;
+	struct gpio_desc *clk_internal;
+	struct net_device *netdev;
+	struct napi_struct napi;
+	buffer_t *rx_buff_tab[RX_DESCS], *tx_buff_tab[TX_DESCS];
+	struct desc *desc_tab;	/* coherent */
+	dma_addr_t desc_tab_phys;
+	unsigned int id;
+	unsigned int clock_type, clock_rate, loopback;
+	unsigned int initialized, carrier;
+	u8 hdlc_cfg;
+	u32 clock_reg;
+};
+
+/* 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 DEFINE_SPINLOCK(npe_lock);
+
+/*****************************************************************************
+ * 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)) {
+		pr_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_PULSE_DISABLED | 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 = port->clock_reg;
+	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) {
+		pr_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")) {
+		pr_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);
+		if (err)
+			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 int queue_get_desc(unsigned int queue, struct port *port,
+				 int is_tx)
+{
+	u32 phys, tab_phys, n_desc;
+	struct desc *tab;
+
+	phys = qmgr_get_entry(queue);
+	if (!phys)
+		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_desc(phys, desc);
+	BUG_ON(phys & 0x1F);
+	qmgr_put_entry(queue, phys);
+	/* Don't check for queue overflow here, we've allocated sufficient
+	 * length and queues >= 32 don't support this check anyway.
+	 */
+}
+
+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(port->rxq);
+	napi_schedule(&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 = port->rxq;
+	unsigned int rxfreeq = port->rxfreeq;
+	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
+
+		n = queue_get_desc(rxq, port, 0);
+		if (n < 0) {
+#if DEBUG_RX
+			printk(KERN_DEBUG "%s: hss_hdlc_poll"
+			       " napi_complete\n", dev->name);
+#endif
+			napi_complete(napi);
+			qmgr_enable_irq(rxq);
+			if (!qmgr_stat_empty(rxq) &&
+			    napi_reschedule(napi)) {
+#if DEBUG_RX
+				printk(KERN_DEBUG "%s: hss_hdlc_poll"
+				       " napi_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__
+			skb = netdev_alloc_skb(dev, RX_SIZE);
+			if (skb) {
+				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 */
+			netdev_err(dev, "hss_hdlc_poll: status 0x%02X errors %u\n",
+				   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_for_cpu(&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(port->txdoneq,
+					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_below_low_watermark(port->txreadyq);
+		queue_put_desc(port->txreadyq,
+			       tx_desc_phys(port, n_desc), desc);
+		if (start) { /* TX-ready queue was empty */
+#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->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);
+	mem = kmalloc(bytes, GFP_ATOMIC);
+	if (!mem) {
+		dev_kfree_skb(skb);
+		dev->stats.tx_dropped++;
+		return NETDEV_TX_OK;
+	}
+	memcpy_swab32(mem, (u32 *)((uintptr_t)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(port->txq, tx_desc_phys(port, n), desc);
+
+	if (qmgr_stat_below_low_watermark(txreadyq)) { /* empty */
+#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_below_low_watermark(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(port->rxfreeq, RX_DESCS, 0, 0,
+				 "%s:RX-free", port->netdev->name);
+	if (err)
+		return err;
+
+	err = qmgr_request_queue(port->rxq, RX_DESCS, 0, 0,
+				 "%s:RX", port->netdev->name);
+	if (err)
+		goto rel_rxfree;
+
+	err = qmgr_request_queue(port->txq, TX_DESCS, 0, 0,
+				 "%s:TX", port->netdev->name);
+	if (err)
+		goto rel_rx;
+
+	err = qmgr_request_queue(port->txreadyq, TX_DESCS, 0, 0,
+				 "%s:TX-ready", port->netdev->name);
+	if (err)
+		goto rel_tx;
+
+	err = qmgr_request_queue(port->txdoneq, TX_DESCS, 0, 0,
+				 "%s:TX-done", port->netdev->name);
+	if (err)
+		goto rel_txready;
+	return 0;
+
+rel_txready:
+	qmgr_release_queue(port->txreadyq);
+rel_tx:
+	qmgr_release_queue(port->txq);
+rel_rx:
+	qmgr_release_queue(port->rxq);
+rel_rxfree:
+	qmgr_release_queue(port->rxfreeq);
+	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(port->rxfreeq);
+	qmgr_release_queue(port->rxq);
+	qmgr_release_queue(port->txdoneq);
+	qmgr_release_queue(port->txq);
+	qmgr_release_queue(port->txreadyq);
+}
+
+static int init_hdlc_queues(struct port *port)
+{
+	int i;
+
+	if (!ports_open) {
+		dma_pool = dma_pool_create(DRV_NAME, &port->netdev->dev,
+					   POOL_ALLOC_SIZE, 32, 0);
+		if (!dma_pool)
+			return -ENOMEM;
+	}
+
+	port->desc_tab = dma_pool_zalloc(dma_pool, GFP_KERNEL,
+					&port->desc_tab_phys);
+	if (!port->desc_tab)
+		return -ENOMEM;
+	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__
+		buff = netdev_alloc_skb(port->netdev, RX_SIZE);
+		if (!buff)
+			return -ENOMEM;
+		data = buff->data;
+#else
+		buff = kmalloc(RX_SIZE, GFP_KERNEL);
+		if (!buff)
+			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 irqreturn_t hss_hdlc_dcd_irq(int irq, void *data)
+{
+	struct net_device *dev = data;
+	struct port *port = dev_to_port(dev);
+	int val;
+
+	val = gpiod_get_value(port->dcd);
+	hss_hdlc_set_carrier(dev, val);
+
+	return IRQ_HANDLED;
+}
+
+static int hss_hdlc_open(struct net_device *dev)
+{
+	struct port *port = dev_to_port(dev);
+	unsigned long flags;
+	int i, err = 0;
+	int val;
+
+	err = hdlc_open(dev);
+	if (err)
+		return err;
+
+	err = hss_load_firmware(port);
+	if (err)
+		goto err_hdlc_close;
+
+	err = request_hdlc_queues(port);
+	if (err)
+		goto err_hdlc_close;
+
+	err = init_hdlc_queues(port);
+	if (err)
+		goto err_destroy_queues;
+
+	spin_lock_irqsave(&npe_lock, flags);
+
+	/* Set the carrier, the GPIO is flagged active low so this will return
+	 * 1 if DCD is asserted.
+	 */
+	val = gpiod_get_value(port->dcd);
+	hss_hdlc_set_carrier(dev, val);
+
+	/* Set up an IRQ for DCD */
+	err = request_irq(gpiod_to_irq(port->dcd), hss_hdlc_dcd_irq, 0, "IXP4xx HSS", dev);
+	if (err) {
+		dev_err(&dev->dev, "ixp4xx_hss: failed to request DCD IRQ (%i)\n", err);
+		goto err_unlock;
+	}
+
+	/* GPIOs are flagged active low so this asserts DTR and RTS */
+	gpiod_set_value(port->dtr, 1);
+	gpiod_set_value(port->rts, 1);
+
+	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->txreadyq,
+			       tx_desc_phys(port, i), tx_desc_ptr(port, i));
+
+	for (i = 0; i < RX_DESCS; i++)
+		queue_put_desc(port->rxfreeq,
+			       rx_desc_phys(port, i), rx_desc_ptr(port, i));
+
+	napi_enable(&port->napi);
+	netif_start_queue(dev);
+
+	qmgr_set_irq(port->rxq, QUEUE_IRQ_SRC_NOT_EMPTY,
+		     hss_hdlc_rx_irq, dev);
+
+	qmgr_set_irq(port->txdoneq, QUEUE_IRQ_SRC_NOT_EMPTY,
+		     hss_hdlc_txdone_irq, dev);
+	qmgr_enable_irq(port->txdoneq);
+
+	ports_open++;
+
+	hss_set_hdlc_cfg(port);
+	hss_config(port);
+
+	hss_start_hdlc(port);
+
+	/* we may already have RX data, enables IRQ */
+	napi_schedule(&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(port->rxq);
+	netif_stop_queue(dev);
+	napi_disable(&port->napi);
+
+	hss_stop_hdlc(port);
+
+	while (queue_get_desc(port->rxfreeq, port, 0) >= 0)
+		buffs--;
+	while (queue_get_desc(port->rxq, port, 0) >= 0)
+		buffs--;
+
+	if (buffs)
+		netdev_crit(dev, "unable to drain RX queue, %i buffer(s) left in NPE\n",
+			    buffs);
+
+	buffs = TX_DESCS;
+	while (queue_get_desc(port->txq, port, 1) >= 0)
+		buffs--; /* cancel TX */
+
+	i = 0;
+	do {
+		while (queue_get_desc(port->txreadyq, port, 1) >= 0)
+			buffs--;
+		if (!buffs)
+			break;
+	} while (++i < MAX_CLOSE_WAIT);
+
+	if (buffs)
+		netdev_crit(dev, "unable to drain TX queue, %i buffer(s) left in NPE\n",
+			    buffs);
+#if DEBUG_CLOSE
+	if (!buffs)
+		printk(KERN_DEBUG "Draining TX queues took %i cycles\n", i);
+#endif
+	qmgr_disable_irq(port->txdoneq);
+
+	free_irq(gpiod_to_irq(port->dcd), dev);
+	/* GPIOs are flagged active low so this de-asserts DTR and RTS */
+	gpiod_set_value(port->dtr, 0);
+	gpiod_set_value(port->rts, 0);
+	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 u32 check_clock(u32 timer_freq, u32 rate, u32 a, u32 b, u32 c,
+		       u32 *best, u32 *best_diff, u32 *reg)
+{
+	/* a is 10-bit, b is 10-bit, c is 12-bit */
+	u64 new_rate;
+	u32 new_diff;
+
+	new_rate = timer_freq * (u64)(c + 1);
+	do_div(new_rate, a * (c + 1) + b + 1);
+	new_diff = abs((u32)new_rate - rate);
+
+	if (new_diff < *best_diff) {
+		*best = new_rate;
+		*best_diff = new_diff;
+		*reg = (a << 22) | (b << 12) | c;
+	}
+	return new_diff;
+}
+
+static void find_best_clock(u32 timer_freq, u32 rate, u32 *best, u32 *reg)
+{
+	u32 a, b, diff = 0xFFFFFFFF;
+
+	a = timer_freq / rate;
+
+	if (a > 0x3FF) { /* 10-bit value - we can go as slow as ca. 65 kb/s */
+		check_clock(timer_freq, rate, 0x3FF, 1, 1, best, &diff, reg);
+		return;
+	}
+	if (a == 0) { /* > 66.666 MHz */
+		a = 1; /* minimum divider is 1 (a = 0, b = 1, c = 1) */
+		rate = timer_freq;
+	}
+
+	if (rate * a == timer_freq) { /* don't divide by 0 later */
+		check_clock(timer_freq, rate, a - 1, 1, 1, best, &diff, reg);
+		return;
+	}
+
+	for (b = 0; b < 0x400; b++) {
+		u64 c = (b + 1) * (u64)rate;
+
+		do_div(c, timer_freq - rate * a);
+		c--;
+		if (c >= 0xFFF) { /* 12-bit - no need to check more 'b's */
+			if (b == 0 && /* also try a bit higher rate */
+			    !check_clock(timer_freq, rate, a - 1, 1, 1, best,
+					 &diff, reg))
+				return;
+			check_clock(timer_freq, rate, a, b, 0xFFF, best,
+				    &diff, reg);
+			return;
+		}
+		if (!check_clock(timer_freq, rate, a, b, c, best, &diff, reg))
+			return;
+		if (!check_clock(timer_freq, rate, a, b, c + 1, best, &diff,
+				 reg))
+			return;
+	}
+}
+
+static int hss_hdlc_set_clock(struct port *port, unsigned int clock_type)
+{
+	switch (clock_type) {
+	case CLOCK_DEFAULT:
+	case CLOCK_EXT:
+		gpiod_set_value(port->clk_internal, 0);
+		return CLOCK_EXT;
+	case CLOCK_INT:
+		gpiod_set_value(port->clk_internal, 1);
+		return CLOCK_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int hss_hdlc_ioctl(struct net_device *dev, struct if_settings *ifs)
+{
+	const size_t size = sizeof(sync_serial_settings);
+	sync_serial_settings new_line;
+	sync_serial_settings __user *line = ifs->ifs_ifsu.sync;
+	struct port *port = dev_to_port(dev);
+	unsigned long flags;
+	int clk;
+
+	switch (ifs->type) {
+	case IF_GET_IFACE:
+		ifs->type = IF_IFACE_V35;
+		if (ifs->size < size) {
+			ifs->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 = port->clock_rate;
+		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;
+		hss_hdlc_set_clock(port, 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 */
+		if (clk == CLOCK_INT) {
+			find_best_clock(IXP4XX_TIMER_FREQ,
+					new_line.clock_rate,
+					&port->clock_rate, &port->clock_reg);
+		} else {
+			port->clock_rate = 0;
+			port->clock_reg = CLK42X_SPEED_2048KHZ;
+		}
+		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, ifs);
+	}
+}
+
+/*****************************************************************************
+ * initialization
+ ****************************************************************************/
+
+static const struct net_device_ops hss_hdlc_ops = {
+	.ndo_open       = hss_hdlc_open,
+	.ndo_stop       = hss_hdlc_close,
+	.ndo_start_xmit = hdlc_start_xmit,
+	.ndo_siocwandev = hss_hdlc_ioctl,
+};
+
+static int ixp4xx_hss_probe(struct platform_device *pdev)
+{
+	struct of_phandle_args queue_spec;
+	struct of_phandle_args npe_spec;
+	struct device *dev = &pdev->dev;
+	struct net_device *ndev;
+	struct device_node *np;
+	struct regmap *rmap;
+	struct port *port;
+	hdlc_device *hdlc;
+	int err;
+	u32 val;
+
+	/*
+	 * Go into the syscon and check if we have the HSS and HDLC
+	 * features available, else this will not work.
+	 */
+	rmap = syscon_regmap_lookup_by_compatible("syscon");
+	if (IS_ERR(rmap))
+		return dev_err_probe(dev, PTR_ERR(rmap),
+				     "failed to look up syscon\n");
+
+	val = cpu_ixp4xx_features(rmap);
+
+	if ((val & (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS)) !=
+	    (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS)) {
+		dev_err(dev, "HDLC and HSS feature unavailable in platform\n");
+		return -ENODEV;
+	}
+
+	np = dev->of_node;
+
+	port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+
+	err = of_parse_phandle_with_fixed_args(np, "intel,npe-handle", 1, 0,
+					       &npe_spec);
+	if (err)
+		return dev_err_probe(dev, err, "no NPE engine specified\n");
+	/* NPE ID 0x00, 0x10, 0x20... */
+	port->npe = npe_request(npe_spec.args[0] << 4);
+	if (!port->npe) {
+		dev_err(dev, "unable to obtain NPE instance\n");
+		return -ENODEV;
+	}
+
+	/* Get the TX ready queue as resource from queue manager */
+	err = of_parse_phandle_with_fixed_args(np, "intek,queue-chl-txready", 1, 0,
+					       &queue_spec);
+	if (err)
+		return dev_err_probe(dev, err, "no txready queue phandle\n");
+	port->txreadyq = queue_spec.args[0];
+	/* Get the RX trig queue as resource from queue manager */
+	err = of_parse_phandle_with_fixed_args(np, "intek,queue-chl-rxtrig", 1, 0,
+					       &queue_spec);
+	if (err)
+		return dev_err_probe(dev, err, "no rxtrig queue phandle\n");
+	port->rxtrigq = queue_spec.args[0];
+	/* Get the RX queue as resource from queue manager */
+	err = of_parse_phandle_with_fixed_args(np, "intek,queue-pkt-rx", 1, 0,
+					       &queue_spec);
+	if (err)
+		return dev_err_probe(dev, err, "no RX queue phandle\n");
+	port->rxq = queue_spec.args[0];
+	/* Get the TX queue as resource from queue manager */
+	err = of_parse_phandle_with_fixed_args(np, "intek,queue-pkt-tx", 1, 0,
+					       &queue_spec);
+	if (err)
+		return dev_err_probe(dev, err, "no RX queue phandle\n");
+	port->txq = queue_spec.args[0];
+	/* Get the RX free queue as resource from queue manager */
+	err = of_parse_phandle_with_fixed_args(np, "intek,queue-pkt-rxfree", 1, 0,
+					       &queue_spec);
+	if (err)
+		return dev_err_probe(dev, err, "no RX free queue phandle\n");
+	port->rxfreeq = queue_spec.args[0];
+	/* Get the TX done queue as resource from queue manager */
+	err = of_parse_phandle_with_fixed_args(np, "intek,queue-pkt-txdone", 1, 0,
+					       &queue_spec);
+	if (err)
+		return dev_err_probe(dev, err, "no TX done queue phandle\n");
+	port->txdoneq = queue_spec.args[0];
+
+	/* Obtain all the line control GPIOs */
+	port->cts = devm_gpiod_get(dev, "cts", GPIOD_OUT_LOW);
+	if (IS_ERR(port->cts))
+		return dev_err_probe(dev, PTR_ERR(port->cts), "unable to get CTS GPIO\n");
+	port->rts = devm_gpiod_get(dev, "rts", GPIOD_OUT_LOW);
+	if (IS_ERR(port->rts))
+		return dev_err_probe(dev, PTR_ERR(port->rts), "unable to get RTS GPIO\n");
+	port->dcd = devm_gpiod_get(dev, "dcd", GPIOD_IN);
+	if (IS_ERR(port->dcd))
+		return dev_err_probe(dev, PTR_ERR(port->dcd), "unable to get DCD GPIO\n");
+	port->dtr = devm_gpiod_get(dev, "dtr", GPIOD_OUT_LOW);
+	if (IS_ERR(port->dtr))
+		return dev_err_probe(dev, PTR_ERR(port->dtr), "unable to get DTR GPIO\n");
+	port->clk_internal = devm_gpiod_get(dev, "clk-internal", GPIOD_OUT_LOW);
+	if (IS_ERR(port->clk_internal))
+		return dev_err_probe(dev, PTR_ERR(port->clk_internal),
+				     "unable to get CLK internal GPIO\n");
+
+	ndev = alloc_hdlcdev(port);
+	port->netdev = alloc_hdlcdev(port);
+	if (!port->netdev) {
+		err = -ENOMEM;
+		goto err_plat;
+	}
+
+	SET_NETDEV_DEV(ndev, &pdev->dev);
+	hdlc = dev_to_hdlc(ndev);
+	hdlc->attach = hss_hdlc_attach;
+	hdlc->xmit = hss_hdlc_xmit;
+	ndev->netdev_ops = &hss_hdlc_ops;
+	ndev->tx_queue_len = 100;
+	port->clock_type = CLOCK_EXT;
+	port->clock_rate = 0;
+	port->clock_reg = CLK42X_SPEED_2048KHZ;
+	port->id = pdev->id;
+	port->dev = &pdev->dev;
+	netif_napi_add_weight(ndev, &port->napi, hss_hdlc_poll, NAPI_WEIGHT);
+
+	err = register_hdlc_device(ndev);
+	if (err)
+		goto err_free_netdev;
+
+	platform_set_drvdata(pdev, port);
+
+	netdev_info(ndev, "initialized\n");
+	return 0;
+
+err_free_netdev:
+	free_netdev(ndev);
+err_plat:
+	npe_release(port->npe);
+	return err;
+}
+
+static int ixp4xx_hss_remove(struct platform_device *pdev)
+{
+	struct port *port = platform_get_drvdata(pdev);
+
+	unregister_hdlc_device(port->netdev);
+	free_netdev(port->netdev);
+	npe_release(port->npe);
+	return 0;
+}
+
+static struct platform_driver ixp4xx_hss_driver = {
+	.driver.name	= DRV_NAME,
+	.probe		= ixp4xx_hss_probe,
+	.remove		= ixp4xx_hss_remove,
+};
+module_platform_driver(ixp4xx_hss_driver);
+
+MODULE_AUTHOR("Krzysztof Halasa");
+MODULE_DESCRIPTION("Intel IXP4xx HSS driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:ixp4xx_hss");