drivers/usb/c67x00/c67x00-ll-hpi.c - linux/kernel/git/paulmck/linux-rcu - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * c67x00-ll-hpi.c: Cypress C67X00 USB Low level interface using HPI
  *
  * Copyright (C) 2006-2008 Barco N.V.
  *    Derived from the Cypress cy7c67200/300 ezusb linux driver and
  *    based on multiple host controller drivers inside the linux kernel.
  */

 #include <asm/byteorder.h>
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/jiffies.h>
 #include <linux/usb/c67x00.h>
 #include "c67x00.h"

 #define COMM_REGS 14

 struct c67x00_lcp_int_data {
 	u16 regs[COMM_REGS];
 };

 /* -------------------------------------------------------------------------- */
 /* Interface definitions */

 #define COMM_ACK			0x0FED
 #define COMM_NAK			0xDEAD

 #define COMM_RESET			0xFA50
 #define COMM_EXEC_INT			0xCE01
 #define COMM_INT_NUM			0x01C2

 /* Registers 0 to COMM_REGS-1 */
 #define COMM_R(x)			(0x01C4 + 2 * (x))

 #define HUSB_SIE_pCurrentTDPtr(x)	((x) ? 0x01B2 : 0x01B0)
 #define HUSB_SIE_pTDListDone_Sem(x)	((x) ? 0x01B8 : 0x01B6)
 #define HUSB_pEOT			0x01B4

 /* Software interrupts */
 /* 114, 115: */
 #define HUSB_SIE_INIT_INT(x)		((x) ? 0x0073 : 0x0072)
 #define HUSB_RESET_INT			0x0074

 #define SUSB_INIT_INT			0x0071
 #define SUSB_INIT_INT_LOC		(SUSB_INIT_INT * 2)

 /* -----------------------------------------------------------------------
  * HPI implementation
  *
  * The c67x00 chip also support control via SPI or HSS serial
  * interfaces. However, this driver assumes that register access can
  * be performed from IRQ context. While this is a safe assumption with
  * the HPI interface, it is not true for the serial interfaces.
  */

 /* HPI registers */
 #define HPI_DATA	0
 #define HPI_MAILBOX	1
 #define HPI_ADDR	2
 #define HPI_STATUS	3

 /*
  * According to CY7C67300 specification (tables 140 and 141) HPI read and
  * write cycle duration Tcyc must be at least 6T long, where T is 1/48MHz,
  * which is 125ns.
  */
 #define HPI_T_CYC_NS	125

 static inline u16 hpi_read_reg(struct c67x00_device *dev, int reg)
 {
 	ndelay(HPI_T_CYC_NS);
 	return __raw_readw(dev->hpi.base + reg * dev->hpi.regstep);
 }

 static inline void hpi_write_reg(struct c67x00_device *dev, int reg, u16 value)
 {
 	ndelay(HPI_T_CYC_NS);
 	__raw_writew(value, dev->hpi.base + reg * dev->hpi.regstep);
 }

 static inline u16 hpi_read_word_nolock(struct c67x00_device *dev, u16 reg)
 {
 	hpi_write_reg(dev, HPI_ADDR, reg);
 	return hpi_read_reg(dev, HPI_DATA);
 }

 static u16 hpi_read_word(struct c67x00_device *dev, u16 reg)
 {
 	u16 value;
 	unsigned long flags;

 	spin_lock_irqsave(&dev->hpi.lock, flags);
 	value = hpi_read_word_nolock(dev, reg);
 	spin_unlock_irqrestore(&dev->hpi.lock, flags);

 	return value;
 }

 static void hpi_write_word_nolock(struct c67x00_device *dev, u16 reg, u16 value)
 {
 	hpi_write_reg(dev, HPI_ADDR, reg);
 	hpi_write_reg(dev, HPI_DATA, value);
 }

 static void hpi_write_word(struct c67x00_device *dev, u16 reg, u16 value)
 {
 	unsigned long flags;

 	spin_lock_irqsave(&dev->hpi.lock, flags);
 	hpi_write_word_nolock(dev, reg, value);
 	spin_unlock_irqrestore(&dev->hpi.lock, flags);
 }

 /*
  * Only data is little endian, addr has cpu endianess
  */
 static void hpi_write_words_le16(struct c67x00_device *dev, u16 addr,
 				 __le16 *data, u16 count)
 {
 	unsigned long flags;
 	int i;

 	spin_lock_irqsave(&dev->hpi.lock, flags);

 	hpi_write_reg(dev, HPI_ADDR, addr);
 	for (i = 0; i < count; i++)
 		hpi_write_reg(dev, HPI_DATA, le16_to_cpu(*data++));

 	spin_unlock_irqrestore(&dev->hpi.lock, flags);
 }

 /*
  * Only data is little endian, addr has cpu endianess
  */
 static void hpi_read_words_le16(struct c67x00_device *dev, u16 addr,
 				__le16 *data, u16 count)
 {
 	unsigned long flags;
 	int i;

 	spin_lock_irqsave(&dev->hpi.lock, flags);
 	hpi_write_reg(dev, HPI_ADDR, addr);
 	for (i = 0; i < count; i++)
 		*data++ = cpu_to_le16(hpi_read_reg(dev, HPI_DATA));

 	spin_unlock_irqrestore(&dev->hpi.lock, flags);
 }

 static void hpi_set_bits(struct c67x00_device *dev, u16 reg, u16 mask)
 {
 	u16 value;
 	unsigned long flags;

 	spin_lock_irqsave(&dev->hpi.lock, flags);
 	value = hpi_read_word_nolock(dev, reg);
 	hpi_write_word_nolock(dev, reg, value | mask);
 	spin_unlock_irqrestore(&dev->hpi.lock, flags);
 }

 static void hpi_clear_bits(struct c67x00_device *dev, u16 reg, u16 mask)
 {
 	u16 value;
 	unsigned long flags;

 	spin_lock_irqsave(&dev->hpi.lock, flags);
 	value = hpi_read_word_nolock(dev, reg);
 	hpi_write_word_nolock(dev, reg, value & ~mask);
 	spin_unlock_irqrestore(&dev->hpi.lock, flags);
 }

 static u16 hpi_recv_mbox(struct c67x00_device *dev)
 {
 	u16 value;
 	unsigned long flags;

 	spin_lock_irqsave(&dev->hpi.lock, flags);
 	value = hpi_read_reg(dev, HPI_MAILBOX);
 	spin_unlock_irqrestore(&dev->hpi.lock, flags);

 	return value;
 }

 static u16 hpi_send_mbox(struct c67x00_device *dev, u16 value)
 {
 	unsigned long flags;

 	spin_lock_irqsave(&dev->hpi.lock, flags);
 	hpi_write_reg(dev, HPI_MAILBOX, value);
 	spin_unlock_irqrestore(&dev->hpi.lock, flags);

 	return value;
 }

 u16 c67x00_ll_hpi_status(struct c67x00_device *dev)
 {
 	u16 value;
 	unsigned long flags;

 	spin_lock_irqsave(&dev->hpi.lock, flags);
 	value = hpi_read_reg(dev, HPI_STATUS);
 	spin_unlock_irqrestore(&dev->hpi.lock, flags);

 	return value;
 }

 void c67x00_ll_hpi_reg_init(struct c67x00_device *dev)
 {
 	int i;

 	hpi_recv_mbox(dev);
 	c67x00_ll_hpi_status(dev);
 	hpi_write_word(dev, HPI_IRQ_ROUTING_REG, 0);

 	for (i = 0; i < C67X00_SIES; i++) {
 		hpi_write_word(dev, SIEMSG_REG(i), 0);
 		hpi_read_word(dev, SIEMSG_REG(i));
 	}
 }

 void c67x00_ll_hpi_enable_sofeop(struct c67x00_sie *sie)
 {
 	hpi_set_bits(sie->dev, HPI_IRQ_ROUTING_REG,
 		     SOFEOP_TO_HPI_EN(sie->sie_num));
 }

 void c67x00_ll_hpi_disable_sofeop(struct c67x00_sie *sie)
 {
 	hpi_clear_bits(sie->dev, HPI_IRQ_ROUTING_REG,
 		       SOFEOP_TO_HPI_EN(sie->sie_num));
 }

 /* -------------------------------------------------------------------------- */
 /* Transactions */

 static inline int ll_recv_msg(struct c67x00_device *dev)
 {
 	u16 res;

 	res = wait_for_completion_timeout(&dev->hpi.lcp.msg_received, 5 * HZ);
 	WARN_ON(!res);

 	return (res == 0) ? -EIO : 0;
 }

 /* -------------------------------------------------------------------------- */
 /* General functions */

 u16 c67x00_ll_fetch_siemsg(struct c67x00_device *dev, int sie_num)
 {
 	u16 val;

 	val = hpi_read_word(dev, SIEMSG_REG(sie_num));
 	/* clear register to allow next message */
 	hpi_write_word(dev, SIEMSG_REG(sie_num), 0);

 	return val;
 }

 u16 c67x00_ll_get_usb_ctl(struct c67x00_sie *sie)
 {
 	return hpi_read_word(sie->dev, USB_CTL_REG(sie->sie_num));
 }

 /*
  * c67x00_ll_usb_clear_status - clear the USB status bits
  */
 void c67x00_ll_usb_clear_status(struct c67x00_sie *sie, u16 bits)
 {
 	hpi_write_word(sie->dev, USB_STAT_REG(sie->sie_num), bits);
 }

 u16 c67x00_ll_usb_get_status(struct c67x00_sie *sie)
 {
 	return hpi_read_word(sie->dev, USB_STAT_REG(sie->sie_num));
 }

 /* -------------------------------------------------------------------------- */

 static int c67x00_comm_exec_int(struct c67x00_device *dev, u16 nr,
 				struct c67x00_lcp_int_data *data)
 {
 	int i, rc;

 	mutex_lock(&dev->hpi.lcp.mutex);
 	hpi_write_word(dev, COMM_INT_NUM, nr);
 	for (i = 0; i < COMM_REGS; i++)
 		hpi_write_word(dev, COMM_R(i), data->regs[i]);
 	hpi_send_mbox(dev, COMM_EXEC_INT);
 	rc = ll_recv_msg(dev);
 	mutex_unlock(&dev->hpi.lcp.mutex);

 	return rc;
 }

 /* -------------------------------------------------------------------------- */
 /* Host specific functions */

 void c67x00_ll_set_husb_eot(struct c67x00_device *dev, u16 value)
 {
 	mutex_lock(&dev->hpi.lcp.mutex);
 	hpi_write_word(dev, HUSB_pEOT, value);
 	mutex_unlock(&dev->hpi.lcp.mutex);
 }

 static inline void c67x00_ll_husb_sie_init(struct c67x00_sie *sie)
 {
 	struct c67x00_device *dev = sie->dev;
 	struct c67x00_lcp_int_data data;
 	int rc;

 	rc = c67x00_comm_exec_int(dev, HUSB_SIE_INIT_INT(sie->sie_num), &data);
 	BUG_ON(rc); /* No return path for error code; crash spectacularly */
 }

 void c67x00_ll_husb_reset(struct c67x00_sie *sie, int port)
 {
 	struct c67x00_device *dev = sie->dev;
 	struct c67x00_lcp_int_data data;
 	int rc;

 	data.regs[0] = 50;	/* Reset USB port for 50ms */
 	data.regs[1] = port | (sie->sie_num << 1);
 	rc = c67x00_comm_exec_int(dev, HUSB_RESET_INT, &data);
 	BUG_ON(rc); /* No return path for error code; crash spectacularly */
 }

 void c67x00_ll_husb_set_current_td(struct c67x00_sie *sie, u16 addr)
 {
 	hpi_write_word(sie->dev, HUSB_SIE_pCurrentTDPtr(sie->sie_num), addr);
 }

 u16 c67x00_ll_husb_get_current_td(struct c67x00_sie *sie)
 {
 	return hpi_read_word(sie->dev, HUSB_SIE_pCurrentTDPtr(sie->sie_num));
 }

 u16 c67x00_ll_husb_get_frame(struct c67x00_sie *sie)
 {
 	return hpi_read_word(sie->dev, HOST_FRAME_REG(sie->sie_num));
 }

 void c67x00_ll_husb_init_host_port(struct c67x00_sie *sie)
 {
 	/* Set port into host mode */
 	hpi_set_bits(sie->dev, USB_CTL_REG(sie->sie_num), HOST_MODE);
 	c67x00_ll_husb_sie_init(sie);
 	/* Clear interrupts */
 	c67x00_ll_usb_clear_status(sie, HOST_STAT_MASK);
 	/* Check */
 	if (!(hpi_read_word(sie->dev, USB_CTL_REG(sie->sie_num)) & HOST_MODE))
 		dev_warn(sie_dev(sie),
 			 "SIE %d not set to host mode\n", sie->sie_num);
 }

 void c67x00_ll_husb_reset_port(struct c67x00_sie *sie, int port)
 {
 	/* Clear connect change */
 	c67x00_ll_usb_clear_status(sie, PORT_CONNECT_CHANGE(port));

 	/* Enable interrupts */
 	hpi_set_bits(sie->dev, HPI_IRQ_ROUTING_REG,
 		     SOFEOP_TO_CPU_EN(sie->sie_num));
 	hpi_set_bits(sie->dev, HOST_IRQ_EN_REG(sie->sie_num),
 		     SOF_EOP_IRQ_EN | DONE_IRQ_EN);

 	/* Enable pull down transistors */
 	hpi_set_bits(sie->dev, USB_CTL_REG(sie->sie_num), PORT_RES_EN(port));
 }

 /* -------------------------------------------------------------------------- */

 void c67x00_ll_irq(struct c67x00_device *dev, u16 int_status)
 {
 	if ((int_status & MBX_OUT_FLG) == 0)
 		return;

 	dev->hpi.lcp.last_msg = hpi_recv_mbox(dev);
 	complete(&dev->hpi.lcp.msg_received);
 }

 /* -------------------------------------------------------------------------- */

 int c67x00_ll_reset(struct c67x00_device *dev)
 {
 	int rc;

 	mutex_lock(&dev->hpi.lcp.mutex);
 	hpi_send_mbox(dev, COMM_RESET);
 	rc = ll_recv_msg(dev);
 	mutex_unlock(&dev->hpi.lcp.mutex);

 	return rc;
 }

 /* -------------------------------------------------------------------------- */

 /*
  * c67x00_ll_write_mem_le16 - write into c67x00 memory
  * Only data is little endian, addr has cpu endianess.
  */
 void c67x00_ll_write_mem_le16(struct c67x00_device *dev, u16 addr,
 			      void *data, int len)
 {
 	u8 *buf = data;

 	/* Sanity check */
 	if (addr + len > 0xffff) {
 		dev_err(&dev->pdev->dev,
 			"Trying to write beyond writable region!\n");
 		return;
 	}

 	if (addr & 0x01) {
 		/* unaligned access */
 		u16 tmp;
 		tmp = hpi_read_word(dev, addr - 1);
 		tmp = (tmp & 0x00ff) | (*buf++ << 8);
 		hpi_write_word(dev, addr - 1, tmp);
 		addr++;
 		len--;
 	}

 	hpi_write_words_le16(dev, addr, (__le16 *)buf, len / 2);
 	buf += len & ~0x01;
 	addr += len & ~0x01;
 	len &= 0x01;

 	if (len) {
 		u16 tmp;
 		tmp = hpi_read_word(dev, addr);
 		tmp = (tmp & 0xff00) | *buf;
 		hpi_write_word(dev, addr, tmp);
 	}
 }

 /*
  * c67x00_ll_read_mem_le16 - read from c67x00 memory
  * Only data is little endian, addr has cpu endianess.
  */
 void c67x00_ll_read_mem_le16(struct c67x00_device *dev, u16 addr,
 			     void *data, int len)
 {
 	u8 *buf = data;

 	if (addr & 0x01) {
 		/* unaligned access */
 		u16 tmp;
 		tmp = hpi_read_word(dev, addr - 1);
 		*buf++ = (tmp >> 8) & 0x00ff;
 		addr++;
 		len--;
 	}

 	hpi_read_words_le16(dev, addr, (__le16 *)buf, len / 2);
 	buf += len & ~0x01;
 	addr += len & ~0x01;
 	len &= 0x01;

 	if (len) {
 		u16 tmp;
 		tmp = hpi_read_word(dev, addr);
 		*buf = tmp & 0x00ff;
 	}
 }

 /* -------------------------------------------------------------------------- */

 void c67x00_ll_init(struct c67x00_device *dev)
 {
 	mutex_init(&dev->hpi.lcp.mutex);
 	init_completion(&dev->hpi.lcp.msg_received);
 }

 void c67x00_ll_release(struct c67x00_device *dev)
 {
 }
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* c67x00-ll-hpi.c: Cypress C67X00 USB Low level interface using HPI
	*
	* Copyright (C) 2006-2008 Barco N.V.
	* Derived from the Cypress cy7c67200/300 ezusb linux driver and
	* based on multiple host controller drivers inside the linux kernel.
	*/

	#include <asm/byteorder.h>
	#include <linux/delay.h>
	#include <linux/io.h>
	#include <linux/jiffies.h>
	#include <linux/usb/c67x00.h>
	#include "c67x00.h"

	#define COMM_REGS 14

	struct c67x00_lcp_int_data {
	u16 regs[COMM_REGS];
	};

	/* -------------------------------------------------------------------------- */
	/* Interface definitions */

	#define COMM_ACK 0x0FED
	#define COMM_NAK 0xDEAD

	#define COMM_RESET 0xFA50
	#define COMM_EXEC_INT 0xCE01
	#define COMM_INT_NUM 0x01C2

	/* Registers 0 to COMM_REGS-1 */
	#define COMM_R(x) (0x01C4 + 2 * (x))

	#define HUSB_SIE_pCurrentTDPtr(x) ((x) ? 0x01B2 : 0x01B0)
	#define HUSB_SIE_pTDListDone_Sem(x) ((x) ? 0x01B8 : 0x01B6)
	#define HUSB_pEOT 0x01B4

	/* Software interrupts */
	/* 114, 115: */
	#define HUSB_SIE_INIT_INT(x) ((x) ? 0x0073 : 0x0072)
	#define HUSB_RESET_INT 0x0074

	#define SUSB_INIT_INT 0x0071
	#define SUSB_INIT_INT_LOC (SUSB_INIT_INT * 2)

	/* -----------------------------------------------------------------------
	* HPI implementation
	*
	* The c67x00 chip also support control via SPI or HSS serial
	* interfaces. However, this driver assumes that register access can
	* be performed from IRQ context. While this is a safe assumption with
	* the HPI interface, it is not true for the serial interfaces.
	*/

	/* HPI registers */
	#define HPI_DATA 0
	#define HPI_MAILBOX 1
	#define HPI_ADDR 2
	#define HPI_STATUS 3

	/*
	* According to CY7C67300 specification (tables 140 and 141) HPI read and
	* write cycle duration Tcyc must be at least 6T long, where T is 1/48MHz,
	* which is 125ns.
	*/
	#define HPI_T_CYC_NS 125

	static inline u16 hpi_read_reg(struct c67x00_device *dev, int reg)
	{
	ndelay(HPI_T_CYC_NS);
	return __raw_readw(dev->hpi.base + reg * dev->hpi.regstep);
	}

	static inline void hpi_write_reg(struct c67x00_device *dev, int reg, u16 value)
	{
	ndelay(HPI_T_CYC_NS);
	__raw_writew(value, dev->hpi.base + reg * dev->hpi.regstep);
	}

	static inline u16 hpi_read_word_nolock(struct c67x00_device *dev, u16 reg)
	{
	hpi_write_reg(dev, HPI_ADDR, reg);
	return hpi_read_reg(dev, HPI_DATA);
	}

	static u16 hpi_read_word(struct c67x00_device *dev, u16 reg)
	{
	u16 value;
	unsigned long flags;

	spin_lock_irqsave(&dev->hpi.lock, flags);
	value = hpi_read_word_nolock(dev, reg);
	spin_unlock_irqrestore(&dev->hpi.lock, flags);

	return value;
	}

	static void hpi_write_word_nolock(struct c67x00_device *dev, u16 reg, u16 value)
	{
	hpi_write_reg(dev, HPI_ADDR, reg);
	hpi_write_reg(dev, HPI_DATA, value);
	}

	static void hpi_write_word(struct c67x00_device *dev, u16 reg, u16 value)
	{
	unsigned long flags;

	spin_lock_irqsave(&dev->hpi.lock, flags);
	hpi_write_word_nolock(dev, reg, value);
	spin_unlock_irqrestore(&dev->hpi.lock, flags);
	}

	/*
	* Only data is little endian, addr has cpu endianess
	*/
	static void hpi_write_words_le16(struct c67x00_device *dev, u16 addr,
	__le16 *data, u16 count)
	{
	unsigned long flags;
	int i;

	spin_lock_irqsave(&dev->hpi.lock, flags);

	hpi_write_reg(dev, HPI_ADDR, addr);
	for (i = 0; i < count; i++)
	hpi_write_reg(dev, HPI_DATA, le16_to_cpu(*data++));

	spin_unlock_irqrestore(&dev->hpi.lock, flags);
	}

	/*
	* Only data is little endian, addr has cpu endianess
	*/
	static void hpi_read_words_le16(struct c67x00_device *dev, u16 addr,
	__le16 *data, u16 count)
	{
	unsigned long flags;
	int i;

	spin_lock_irqsave(&dev->hpi.lock, flags);
	hpi_write_reg(dev, HPI_ADDR, addr);
	for (i = 0; i < count; i++)
	*data++ = cpu_to_le16(hpi_read_reg(dev, HPI_DATA));

	spin_unlock_irqrestore(&dev->hpi.lock, flags);
	}

	static void hpi_set_bits(struct c67x00_device *dev, u16 reg, u16 mask)
	{
	u16 value;
	unsigned long flags;

	spin_lock_irqsave(&dev->hpi.lock, flags);
	value = hpi_read_word_nolock(dev, reg);
	hpi_write_word_nolock(dev, reg, value \| mask);
	spin_unlock_irqrestore(&dev->hpi.lock, flags);
	}

	static void hpi_clear_bits(struct c67x00_device *dev, u16 reg, u16 mask)
	{
	u16 value;
	unsigned long flags;

	spin_lock_irqsave(&dev->hpi.lock, flags);
	value = hpi_read_word_nolock(dev, reg);
	hpi_write_word_nolock(dev, reg, value & ~mask);
	spin_unlock_irqrestore(&dev->hpi.lock, flags);
	}

	static u16 hpi_recv_mbox(struct c67x00_device *dev)
	{
	u16 value;
	unsigned long flags;

	spin_lock_irqsave(&dev->hpi.lock, flags);
	value = hpi_read_reg(dev, HPI_MAILBOX);
	spin_unlock_irqrestore(&dev->hpi.lock, flags);

	return value;
	}

	static u16 hpi_send_mbox(struct c67x00_device *dev, u16 value)
	{
	unsigned long flags;

	spin_lock_irqsave(&dev->hpi.lock, flags);
	hpi_write_reg(dev, HPI_MAILBOX, value);
	spin_unlock_irqrestore(&dev->hpi.lock, flags);

	return value;
	}

	u16 c67x00_ll_hpi_status(struct c67x00_device *dev)
	{
	u16 value;
	unsigned long flags;

	spin_lock_irqsave(&dev->hpi.lock, flags);
	value = hpi_read_reg(dev, HPI_STATUS);
	spin_unlock_irqrestore(&dev->hpi.lock, flags);

	return value;
	}

	void c67x00_ll_hpi_reg_init(struct c67x00_device *dev)
	{
	int i;

	hpi_recv_mbox(dev);
	c67x00_ll_hpi_status(dev);
	hpi_write_word(dev, HPI_IRQ_ROUTING_REG, 0);

	for (i = 0; i < C67X00_SIES; i++) {
	hpi_write_word(dev, SIEMSG_REG(i), 0);
	hpi_read_word(dev, SIEMSG_REG(i));
	}
	}

	void c67x00_ll_hpi_enable_sofeop(struct c67x00_sie *sie)
	{
	hpi_set_bits(sie->dev, HPI_IRQ_ROUTING_REG,
	SOFEOP_TO_HPI_EN(sie->sie_num));
	}

	void c67x00_ll_hpi_disable_sofeop(struct c67x00_sie *sie)
	{
	hpi_clear_bits(sie->dev, HPI_IRQ_ROUTING_REG,
	SOFEOP_TO_HPI_EN(sie->sie_num));
	}

	/* -------------------------------------------------------------------------- */
	/* Transactions */

	static inline int ll_recv_msg(struct c67x00_device *dev)
	{
	u16 res;

	res = wait_for_completion_timeout(&dev->hpi.lcp.msg_received, 5 * HZ);
	WARN_ON(!res);

	return (res == 0) ? -EIO : 0;
	}

	/* -------------------------------------------------------------------------- */
	/* General functions */

	u16 c67x00_ll_fetch_siemsg(struct c67x00_device *dev, int sie_num)
	{
	u16 val;

	val = hpi_read_word(dev, SIEMSG_REG(sie_num));
	/* clear register to allow next message */
	hpi_write_word(dev, SIEMSG_REG(sie_num), 0);

	return val;
	}

	u16 c67x00_ll_get_usb_ctl(struct c67x00_sie *sie)
	{
	return hpi_read_word(sie->dev, USB_CTL_REG(sie->sie_num));
	}

	/*
	* c67x00_ll_usb_clear_status - clear the USB status bits
	*/
	void c67x00_ll_usb_clear_status(struct c67x00_sie *sie, u16 bits)
	{
	hpi_write_word(sie->dev, USB_STAT_REG(sie->sie_num), bits);
	}

	u16 c67x00_ll_usb_get_status(struct c67x00_sie *sie)
	{
	return hpi_read_word(sie->dev, USB_STAT_REG(sie->sie_num));
	}

	/* -------------------------------------------------------------------------- */

	static int c67x00_comm_exec_int(struct c67x00_device *dev, u16 nr,
	struct c67x00_lcp_int_data *data)
	{
	int i, rc;

	mutex_lock(&dev->hpi.lcp.mutex);
	hpi_write_word(dev, COMM_INT_NUM, nr);
	for (i = 0; i < COMM_REGS; i++)
	hpi_write_word(dev, COMM_R(i), data->regs[i]);
	hpi_send_mbox(dev, COMM_EXEC_INT);
	rc = ll_recv_msg(dev);
	mutex_unlock(&dev->hpi.lcp.mutex);

	return rc;
	}

	/* -------------------------------------------------------------------------- */
	/* Host specific functions */

	void c67x00_ll_set_husb_eot(struct c67x00_device *dev, u16 value)
	{
	mutex_lock(&dev->hpi.lcp.mutex);
	hpi_write_word(dev, HUSB_pEOT, value);
	mutex_unlock(&dev->hpi.lcp.mutex);
	}

	static inline void c67x00_ll_husb_sie_init(struct c67x00_sie *sie)
	{
	struct c67x00_device *dev = sie->dev;
	struct c67x00_lcp_int_data data;
	int rc;

	rc = c67x00_comm_exec_int(dev, HUSB_SIE_INIT_INT(sie->sie_num), &data);
	BUG_ON(rc); /* No return path for error code; crash spectacularly */
	}

	void c67x00_ll_husb_reset(struct c67x00_sie *sie, int port)
	{
	struct c67x00_device *dev = sie->dev;
	struct c67x00_lcp_int_data data;
	int rc;

	data.regs[0] = 50; /* Reset USB port for 50ms */
	data.regs[1] = port \| (sie->sie_num << 1);
	rc = c67x00_comm_exec_int(dev, HUSB_RESET_INT, &data);
	BUG_ON(rc); /* No return path for error code; crash spectacularly */
	}

	void c67x00_ll_husb_set_current_td(struct c67x00_sie *sie, u16 addr)
	{
	hpi_write_word(sie->dev, HUSB_SIE_pCurrentTDPtr(sie->sie_num), addr);
	}

	u16 c67x00_ll_husb_get_current_td(struct c67x00_sie *sie)
	{
	return hpi_read_word(sie->dev, HUSB_SIE_pCurrentTDPtr(sie->sie_num));
	}

	u16 c67x00_ll_husb_get_frame(struct c67x00_sie *sie)
	{
	return hpi_read_word(sie->dev, HOST_FRAME_REG(sie->sie_num));
	}

	void c67x00_ll_husb_init_host_port(struct c67x00_sie *sie)
	{
	/* Set port into host mode */
	hpi_set_bits(sie->dev, USB_CTL_REG(sie->sie_num), HOST_MODE);
	c67x00_ll_husb_sie_init(sie);
	/* Clear interrupts */
	c67x00_ll_usb_clear_status(sie, HOST_STAT_MASK);
	/* Check */
	if (!(hpi_read_word(sie->dev, USB_CTL_REG(sie->sie_num)) & HOST_MODE))
	dev_warn(sie_dev(sie),
	"SIE %d not set to host mode\n", sie->sie_num);
	}

	void c67x00_ll_husb_reset_port(struct c67x00_sie *sie, int port)
	{
	/* Clear connect change */
	c67x00_ll_usb_clear_status(sie, PORT_CONNECT_CHANGE(port));

	/* Enable interrupts */
	hpi_set_bits(sie->dev, HPI_IRQ_ROUTING_REG,
	SOFEOP_TO_CPU_EN(sie->sie_num));
	hpi_set_bits(sie->dev, HOST_IRQ_EN_REG(sie->sie_num),
	SOF_EOP_IRQ_EN \| DONE_IRQ_EN);

	/* Enable pull down transistors */
	hpi_set_bits(sie->dev, USB_CTL_REG(sie->sie_num), PORT_RES_EN(port));
	}

	/* -------------------------------------------------------------------------- */

	void c67x00_ll_irq(struct c67x00_device *dev, u16 int_status)
	{
	if ((int_status & MBX_OUT_FLG) == 0)
	return;

	dev->hpi.lcp.last_msg = hpi_recv_mbox(dev);
	complete(&dev->hpi.lcp.msg_received);
	}

	/* -------------------------------------------------------------------------- */

	int c67x00_ll_reset(struct c67x00_device *dev)
	{
	int rc;

	mutex_lock(&dev->hpi.lcp.mutex);
	hpi_send_mbox(dev, COMM_RESET);
	rc = ll_recv_msg(dev);
	mutex_unlock(&dev->hpi.lcp.mutex);

	return rc;
	}

	/* -------------------------------------------------------------------------- */

	/*
	* c67x00_ll_write_mem_le16 - write into c67x00 memory
	* Only data is little endian, addr has cpu endianess.
	*/
	void c67x00_ll_write_mem_le16(struct c67x00_device *dev, u16 addr,
	void *data, int len)
	{
	u8 *buf = data;

	/* Sanity check */
	if (addr + len > 0xffff) {
	dev_err(&dev->pdev->dev,
	"Trying to write beyond writable region!\n");
	return;
	}

	if (addr & 0x01) {
	/* unaligned access */
	u16 tmp;
	tmp = hpi_read_word(dev, addr - 1);
	tmp = (tmp & 0x00ff) \| (*buf++ << 8);
	hpi_write_word(dev, addr - 1, tmp);
	addr++;
	len--;
	}

	hpi_write_words_le16(dev, addr, (__le16 *)buf, len / 2);
	buf += len & ~0x01;
	addr += len & ~0x01;
	len &= 0x01;

	if (len) {
	u16 tmp;
	tmp = hpi_read_word(dev, addr);
	tmp = (tmp & 0xff00) \| *buf;
	hpi_write_word(dev, addr, tmp);
	}
	}

	/*
	* c67x00_ll_read_mem_le16 - read from c67x00 memory
	* Only data is little endian, addr has cpu endianess.
	*/
	void c67x00_ll_read_mem_le16(struct c67x00_device *dev, u16 addr,
	void *data, int len)
	{
	u8 *buf = data;

	if (addr & 0x01) {
	/* unaligned access */
	u16 tmp;
	tmp = hpi_read_word(dev, addr - 1);
	*buf++ = (tmp >> 8) & 0x00ff;
	addr++;
	len--;
	}

	hpi_read_words_le16(dev, addr, (__le16 *)buf, len / 2);
	buf += len & ~0x01;
	addr += len & ~0x01;
	len &= 0x01;

	if (len) {
	u16 tmp;
	tmp = hpi_read_word(dev, addr);
	*buf = tmp & 0x00ff;
	}
	}

	/* -------------------------------------------------------------------------- */

	void c67x00_ll_init(struct c67x00_device *dev)
	{
	mutex_init(&dev->hpi.lcp.mutex);
	init_completion(&dev->hpi.lcp.msg_received);
	}

	void c67x00_ll_release(struct c67x00_device *dev)
	{
	}