c67x00-ll-hpi.c

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/*
 * 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.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA  02110-1301  USA.
 */

#include <asm/byteorder.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 assuption 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

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

static inline void hpi_write_reg(struct c67x00_device *dev, int reg, u16 value)
{
    __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 u16 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));
}

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;
}

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

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);
    }
}

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)
{
}