omap_cf.c

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/*
 * omap_cf.c -- OMAP 16xx CompactFlash controller driver
 *
 * Copyright (c) 2005 David Brownell
 *
 * 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.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/slab.h>

#include <pcmcia/ss.h>

#include <mach/hardware.h>
#include <asm/io.h>
#include <asm/sizes.h>

#include <mach/mux.h>
#include <plat/tc.h>


/* NOTE:  don't expect this to support many I/O cards.  The 16xx chips have
 * hard-wired timings to support Compact Flash memory cards; they won't work
 * with various other devices (like WLAN adapters) without some external
 * logic to help out.
 *
 * NOTE:  CF controller docs disagree with address space docs as to where
 * CF_BASE really lives; this is a doc erratum.
 */
#define CF_BASE 0xfffe2800

/* status; read after IRQ */
#define CF_STATUS           (CF_BASE + 0x00)
#   define  CF_STATUS_BAD_READ  (1 << 2)
#   define  CF_STATUS_BAD_WRITE (1 << 1)
#   define  CF_STATUS_CARD_DETECT   (1 << 0)

/* which chipselect (CS0..CS3) is used for CF (active low) */
#define CF_CFG              (CF_BASE + 0x02)

/* card reset */
#define CF_CONTROL          (CF_BASE + 0x04)
#   define  CF_CONTROL_RESET    (1 << 0)

#define omap_cf_present() (!(omap_readw(CF_STATUS) & CF_STATUS_CARD_DETECT))

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

static const char driver_name[] = "omap_cf";

struct omap_cf_socket {
    struct pcmcia_socket    socket;

    struct timer_list   timer;
    unsigned        present:1;
    unsigned        active:1;

    struct platform_device  *pdev;
    unsigned long       phys_cf;
    u_int           irq;
    struct resource     iomem;
};

#define POLL_INTERVAL       (2 * HZ)

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

static int omap_cf_ss_init(struct pcmcia_socket *s)
{
    return 0;
}

/* the timer is primarily to kick this socket's pccardd */
static void omap_cf_timer(unsigned long _cf)
{
    struct omap_cf_socket   *cf = (void *) _cf;
    unsigned        present = omap_cf_present();

    if (present != cf->present) {
        cf->present = present;
        pr_debug("%s: card %s\n", driver_name,
            present ? "present" : "gone");
        pcmcia_parse_events(&cf->socket, SS_DETECT);
    }

    if (cf->active)
        mod_timer(&cf->timer, jiffies + POLL_INTERVAL);
}

/* This irq handler prevents "irqNNN: nobody cared" messages as drivers
 * claim the card's IRQ.  It may also detect some card insertions, but
 * not removals; it can't always eliminate timer irqs.
 */
static irqreturn_t omap_cf_irq(int irq, void *_cf)
{
    omap_cf_timer((unsigned long)_cf);
    return IRQ_HANDLED;
}

static int omap_cf_get_status(struct pcmcia_socket *s, u_int *sp)
{
    if (!sp)
        return -EINVAL;

    /* NOTE CF is always 3VCARD */
    if (omap_cf_present()) {
        struct omap_cf_socket   *cf;

        *sp = SS_READY | SS_DETECT | SS_POWERON | SS_3VCARD;
        cf = container_of(s, struct omap_cf_socket, socket);
        s->pcmcia_irq = 0;
        s->pci_irq = cf->irq;
    } else
        *sp = 0;
    return 0;
}

static int
omap_cf_set_socket(struct pcmcia_socket *sock, struct socket_state_t *s)
{
    u16     control;

    /* REVISIT some non-OSK boards may support power switching */
    switch (s->Vcc) {
    case 0:
    case 33:
        break;
    default:
        return -EINVAL;
    }

    control = omap_readw(CF_CONTROL);
    if (s->flags & SS_RESET)
        omap_writew(CF_CONTROL_RESET, CF_CONTROL);
    else
        omap_writew(0, CF_CONTROL);

    pr_debug("%s: Vcc %d, io_irq %d, flags %04x csc %04x\n",
        driver_name, s->Vcc, s->io_irq, s->flags, s->csc_mask);

    return 0;
}

static int omap_cf_ss_suspend(struct pcmcia_socket *s)
{
    pr_debug("%s: %s\n", driver_name, __func__);
    return omap_cf_set_socket(s, &dead_socket);
}

/* regions are 2K each:  mem, attrib, io (and reserved-for-ide) */

static int
omap_cf_set_io_map(struct pcmcia_socket *s, struct pccard_io_map *io)
{
    struct omap_cf_socket   *cf;

    cf = container_of(s, struct omap_cf_socket, socket);
    io->flags &= MAP_ACTIVE|MAP_ATTRIB|MAP_16BIT;
    io->start = cf->phys_cf + SZ_4K;
    io->stop = io->start + SZ_2K - 1;
    return 0;
}

static int
omap_cf_set_mem_map(struct pcmcia_socket *s, struct pccard_mem_map *map)
{
    struct omap_cf_socket   *cf;

    if (map->card_start)
        return -EINVAL;
    cf = container_of(s, struct omap_cf_socket, socket);
    map->static_start = cf->phys_cf;
    map->flags &= MAP_ACTIVE|MAP_ATTRIB|MAP_16BIT;
    if (map->flags & MAP_ATTRIB)
        map->static_start += SZ_2K;
    return 0;
}

static struct pccard_operations omap_cf_ops = {
    .init           = omap_cf_ss_init,
    .suspend        = omap_cf_ss_suspend,
    .get_status     = omap_cf_get_status,
    .set_socket     = omap_cf_set_socket,
    .set_io_map     = omap_cf_set_io_map,
    .set_mem_map        = omap_cf_set_mem_map,
};

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

/*
 * NOTE:  right now the only board-specific platform_data is
 * "what chipselect is used".  Boards could want more.
 */

static int __init omap_cf_probe(struct platform_device *pdev)
{
    unsigned        seg;
    struct omap_cf_socket   *cf;
    int         irq;
    int         status;

    seg = (int) pdev->dev.platform_data;
    if (seg == 0 || seg > 3)
        return -ENODEV;

    /* either CFLASH.IREQ (INT_1610_CF) or some GPIO */
    irq = platform_get_irq(pdev, 0);
    if (irq < 0)
        return -EINVAL;

    cf = kzalloc(sizeof *cf, GFP_KERNEL);
    if (!cf)
        return -ENOMEM;
    init_timer(&cf->timer);
    cf->timer.function = omap_cf_timer;
    cf->timer.data = (unsigned long) cf;

    cf->pdev = pdev;
    platform_set_drvdata(pdev, cf);

    /* this primarily just shuts up irq handling noise */
    status = request_irq(irq, omap_cf_irq, IRQF_SHARED,
            driver_name, cf);
    if (status < 0)
        goto fail0;
    cf->irq = irq;
    cf->socket.pci_irq = irq;

    switch (seg) {
    /* NOTE: CS0 could be configured too ... */
    case 1:
        cf->phys_cf = OMAP_CS1_PHYS;
        break;
    case 2:
        cf->phys_cf = OMAP_CS2_PHYS;
        break;
    case 3:
        cf->phys_cf = omap_cs3_phys();
        break;
    default:
        goto  fail1;
    }
    cf->iomem.start = cf->phys_cf;
    cf->iomem.end = cf->iomem.end + SZ_8K - 1;
    cf->iomem.flags = IORESOURCE_MEM;

    /* pcmcia layer only remaps "real" memory */
    cf->socket.io_offset = (unsigned long)
            ioremap(cf->phys_cf + SZ_4K, SZ_2K);
    if (!cf->socket.io_offset)
        goto fail1;

    if (!request_mem_region(cf->phys_cf, SZ_8K, driver_name))
        goto fail1;

    /* NOTE:  CF conflicts with MMC1 */
    omap_cfg_reg(W11_1610_CF_CD1);
    omap_cfg_reg(P11_1610_CF_CD2);
    omap_cfg_reg(R11_1610_CF_IOIS16);
    omap_cfg_reg(V10_1610_CF_IREQ);
    omap_cfg_reg(W10_1610_CF_RESET);

    omap_writew(~(1 << seg), CF_CFG);

    pr_info("%s: cs%d on irq %d\n", driver_name, seg, irq);

    /* NOTE:  better EMIFS setup might support more cards; but the
     * TRM only shows how to affect regular flash signals, not their
     * CF/PCMCIA variants...
     */
    pr_debug("%s: cs%d, previous ccs %08x acs %08x\n", driver_name,
        seg, omap_readl(EMIFS_CCS(seg)), omap_readl(EMIFS_ACS(seg)));
    omap_writel(0x0004a1b3, EMIFS_CCS(seg));    /* synch mode 4 etc */
    omap_writel(0x00000000, EMIFS_ACS(seg));    /* OE hold/setup */

    /* CF uses armxor_ck, which is "always" available */

    pr_debug("%s: sts %04x cfg %04x control %04x %s\n", driver_name,
        omap_readw(CF_STATUS), omap_readw(CF_CFG),
        omap_readw(CF_CONTROL),
        omap_cf_present() ? "present" : "(not present)");

    cf->socket.owner = THIS_MODULE;
    cf->socket.dev.parent = &pdev->dev;
    cf->socket.ops = &omap_cf_ops;
    cf->socket.resource_ops = &pccard_static_ops;
    cf->socket.features = SS_CAP_PCCARD | SS_CAP_STATIC_MAP
                | SS_CAP_MEM_ALIGN;
    cf->socket.map_size = SZ_2K;
    cf->socket.io[0].res = &cf->iomem;

    status = pcmcia_register_socket(&cf->socket);
    if (status < 0)
        goto fail2;

    cf->active = 1;
    mod_timer(&cf->timer, jiffies + POLL_INTERVAL);
    return 0;

fail2:
    release_mem_region(cf->phys_cf, SZ_8K);
fail1:
    if (cf->socket.io_offset)
        iounmap((void __iomem *) cf->socket.io_offset);
    free_irq(irq, cf);
fail0:
    kfree(cf);
    return status;
}

static int __exit omap_cf_remove(struct platform_device *pdev)
{
    struct omap_cf_socket *cf = platform_get_drvdata(pdev);

    cf->active = 0;
    pcmcia_unregister_socket(&cf->socket);
    del_timer_sync(&cf->timer);
    iounmap((void __iomem *) cf->socket.io_offset);
    release_mem_region(cf->phys_cf, SZ_8K);
    free_irq(cf->irq, cf);
    kfree(cf);
    return 0;
}

static struct platform_driver omap_cf_driver = {
    .driver = {
        .name   = (char *) driver_name,
        .owner  = THIS_MODULE,
    },
    .remove     = __exit_p(omap_cf_remove),
};

static int __init omap_cf_init(void)
{
    if (cpu_is_omap16xx())
        return platform_driver_probe(&omap_cf_driver, omap_cf_probe);
    return -ENODEV;
}

static void __exit omap_cf_exit(void)
{
    if (cpu_is_omap16xx())
        platform_driver_unregister(&omap_cf_driver);
}

module_init(omap_cf_init);
module_exit(omap_cf_exit);

MODULE_DESCRIPTION("OMAP CF Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:omap_cf");