at91_cf.c

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/*
 * at91_cf.c -- AT91 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/interrupt.h>
#include <linux/slab.h>
#include <linux/gpio.h>

#include <pcmcia/ss.h>

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

#include <mach/board.h>
#include <mach/at91rm9200_mc.h>
#include <mach/at91_ramc.h>


/*
 * A0..A10 work in each range; A23 indicates I/O space;  A25 is CFRNW;
 * some other bit in {A24,A22..A11} is nREG to flag memory access
 * (vs attributes).  So more than 2KB/region would just be waste.
 * Note: These are offsets from the physical base address.
 */
#define CF_ATTR_PHYS    (0)
#define CF_IO_PHYS  (1 << 23)
#define CF_MEM_PHYS (0x017ff800)

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

static const char driver_name[] = "at91_cf";

struct at91_cf_socket {
    struct pcmcia_socket    socket;

    unsigned        present:1;

    struct platform_device  *pdev;
    struct at91_cf_data *board;

    unsigned long       phys_baseaddr;
};

static inline int at91_cf_present(struct at91_cf_socket *cf)
{
    return !gpio_get_value(cf->board->det_pin);
}

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

static int at91_cf_ss_init(struct pcmcia_socket *s)
{
    return 0;
}

static irqreturn_t at91_cf_irq(int irq, void *_cf)
{
    struct at91_cf_socket *cf = _cf;

    if (irq == gpio_to_irq(cf->board->det_pin)) {
        unsigned present = at91_cf_present(cf);

        /* kick pccard as needed */
        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);
        }
    }

    return IRQ_HANDLED;
}

static int at91_cf_get_status(struct pcmcia_socket *s, u_int *sp)
{
    struct at91_cf_socket   *cf;

    if (!sp)
        return -EINVAL;

    cf = container_of(s, struct at91_cf_socket, socket);

    /* NOTE: CF is always 3VCARD */
    if (at91_cf_present(cf)) {
        int rdy = gpio_is_valid(cf->board->irq_pin);    /* RDY/nIRQ */
        int vcc = gpio_is_valid(cf->board->vcc_pin);

        *sp = SS_DETECT | SS_3VCARD;
        if (!rdy || gpio_get_value(rdy))
            *sp |= SS_READY;
        if (!vcc || gpio_get_value(vcc))
            *sp |= SS_POWERON;
    } else
        *sp = 0;

    return 0;
}

static int
at91_cf_set_socket(struct pcmcia_socket *sock, struct socket_state_t *s)
{
    struct at91_cf_socket   *cf;

    cf = container_of(sock, struct at91_cf_socket, socket);

    /* switch Vcc if needed and possible */
    if (gpio_is_valid(cf->board->vcc_pin)) {
        switch (s->Vcc) {
            case 0:
                gpio_set_value(cf->board->vcc_pin, 0);
                break;
            case 33:
                gpio_set_value(cf->board->vcc_pin, 1);
                break;
            default:
                return -EINVAL;
        }
    }

    /* toggle reset if needed */
    gpio_set_value(cf->board->rst_pin, s->flags & SS_RESET);

    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 at91_cf_ss_suspend(struct pcmcia_socket *s)
{
    return at91_cf_set_socket(s, &dead_socket);
}

/* we already mapped the I/O region */
static int at91_cf_set_io_map(struct pcmcia_socket *s, struct pccard_io_map *io)
{
    struct at91_cf_socket   *cf;
    u32         csr;

    cf = container_of(s, struct at91_cf_socket, socket);
    io->flags &= (MAP_ACTIVE | MAP_16BIT | MAP_AUTOSZ);

    /*
     * Use 16 bit accesses unless/until we need 8-bit i/o space.
     */
    csr = at91_ramc_read(0, AT91_SMC_CSR(cf->board->chipselect)) & ~AT91_SMC_DBW;

    /*
     * NOTE: this CF controller ignores IOIS16, so we can't really do
     * MAP_AUTOSZ.  The 16bit mode allows single byte access on either
     * D0-D7 (even addr) or D8-D15 (odd), so it's close enough for many
     * purposes (and handles ide-cs).
     *
     * The 8bit mode is needed for odd byte access on D0-D7.  It seems
     * some cards only like that way to get at the odd byte, despite
     * CF 3.0 spec table 35 also giving the D8-D15 option.
     */
    if (!(io->flags & (MAP_16BIT | MAP_AUTOSZ))) {
        csr |= AT91_SMC_DBW_8;
        pr_debug("%s: 8bit i/o bus\n", driver_name);
    } else {
        csr |= AT91_SMC_DBW_16;
        pr_debug("%s: 16bit i/o bus\n", driver_name);
    }
    at91_ramc_write(0, AT91_SMC_CSR(cf->board->chipselect), csr);

    io->start = cf->socket.io_offset;
    io->stop = io->start + SZ_2K - 1;

    return 0;
}

/* pcmcia layer maps/unmaps mem regions */
static int
at91_cf_set_mem_map(struct pcmcia_socket *s, struct pccard_mem_map *map)
{
    struct at91_cf_socket   *cf;

    if (map->card_start)
        return -EINVAL;

    cf = container_of(s, struct at91_cf_socket, socket);

    map->flags &= (MAP_ACTIVE | MAP_ATTRIB | MAP_16BIT);
    if (map->flags & MAP_ATTRIB)
        map->static_start = cf->phys_baseaddr + CF_ATTR_PHYS;
    else
        map->static_start = cf->phys_baseaddr + CF_MEM_PHYS;

    return 0;
}

static struct pccard_operations at91_cf_ops = {
    .init           = at91_cf_ss_init,
    .suspend        = at91_cf_ss_suspend,
    .get_status     = at91_cf_get_status,
    .set_socket     = at91_cf_set_socket,
    .set_io_map     = at91_cf_set_io_map,
    .set_mem_map        = at91_cf_set_mem_map,
};

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

static int __init at91_cf_probe(struct platform_device *pdev)
{
    struct at91_cf_socket   *cf;
    struct at91_cf_data *board = pdev->dev.platform_data;
    struct resource     *io;
    int         status;

    if (!board || !gpio_is_valid(board->det_pin) || !gpio_is_valid(board->rst_pin))
        return -ENODEV;

    io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!io)
        return -ENODEV;

    cf = kzalloc(sizeof *cf, GFP_KERNEL);
    if (!cf)
        return -ENOMEM;

    cf->board = board;
    cf->pdev = pdev;
    cf->phys_baseaddr = io->start;
    platform_set_drvdata(pdev, cf);

    /* must be a GPIO; ergo must trigger on both edges */
    status = gpio_request(board->det_pin, "cf_det");
    if (status < 0)
        goto fail0;
    status = request_irq(gpio_to_irq(board->det_pin), at91_cf_irq, 0, driver_name, cf);
    if (status < 0)
        goto fail00;
    device_init_wakeup(&pdev->dev, 1);

    status = gpio_request(board->rst_pin, "cf_rst");
    if (status < 0)
        goto fail0a;

    if (gpio_is_valid(board->vcc_pin)) {
        status = gpio_request(board->vcc_pin, "cf_vcc");
        if (status < 0)
            goto fail0b;
    }

    /*
     * The card driver will request this irq later as needed.
     * but it causes lots of "irqNN: nobody cared" messages
     * unless we report that we handle everything (sigh).
     * (Note:  DK board doesn't wire the IRQ pin...)
     */
    if (gpio_is_valid(board->irq_pin)) {
        status = gpio_request(board->irq_pin, "cf_irq");
        if (status < 0)
            goto fail0c;
        status = request_irq(gpio_to_irq(board->irq_pin), at91_cf_irq,
                IRQF_SHARED, driver_name, cf);
        if (status < 0)
            goto fail0d;
        cf->socket.pci_irq = gpio_to_irq(board->irq_pin);
    } else
        cf->socket.pci_irq = nr_irqs + 1;

    /* pcmcia layer only remaps "real" memory not iospace */
    cf->socket.io_offset = (unsigned long)
            ioremap(cf->phys_baseaddr + CF_IO_PHYS, SZ_2K);
    if (!cf->socket.io_offset) {
        status = -ENXIO;
        goto fail1;
    }

    /* reserve chip-select regions */
    if (!request_mem_region(io->start, resource_size(io), driver_name)) {
        status = -ENXIO;
        goto fail1;
    }

    pr_info("%s: irqs det #%d, io #%d\n", driver_name,
        gpio_to_irq(board->det_pin), gpio_to_irq(board->irq_pin));

    cf->socket.owner = THIS_MODULE;
    cf->socket.dev.parent = &pdev->dev;
    cf->socket.ops = &at91_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 = io;

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

    return 0;

fail2:
    release_mem_region(io->start, resource_size(io));
fail1:
    if (cf->socket.io_offset)
        iounmap((void __iomem *) cf->socket.io_offset);
    if (gpio_is_valid(board->irq_pin)) {
        free_irq(gpio_to_irq(board->irq_pin), cf);
fail0d:
        gpio_free(board->irq_pin);
    }
fail0c:
    if (gpio_is_valid(board->vcc_pin))
        gpio_free(board->vcc_pin);
fail0b:
    gpio_free(board->rst_pin);
fail0a:
    device_init_wakeup(&pdev->dev, 0);
    free_irq(gpio_to_irq(board->det_pin), cf);
fail00:
    gpio_free(board->det_pin);
fail0:
    kfree(cf);
    return status;
}

static int __exit at91_cf_remove(struct platform_device *pdev)
{
    struct at91_cf_socket   *cf = platform_get_drvdata(pdev);
    struct at91_cf_data *board = cf->board;
    struct resource     *io = cf->socket.io[0].res;

    pcmcia_unregister_socket(&cf->socket);
    release_mem_region(io->start, resource_size(io));
    iounmap((void __iomem *) cf->socket.io_offset);
    if (gpio_is_valid(board->irq_pin)) {
        free_irq(gpio_to_irq(board->irq_pin), cf);
        gpio_free(board->irq_pin);
    }
    if (gpio_is_valid(board->vcc_pin))
        gpio_free(board->vcc_pin);
    gpio_free(board->rst_pin);
    device_init_wakeup(&pdev->dev, 0);
    free_irq(gpio_to_irq(board->det_pin), cf);
    gpio_free(board->det_pin);
    kfree(cf);
    return 0;
}

#ifdef  CONFIG_PM

static int at91_cf_suspend(struct platform_device *pdev, pm_message_t mesg)
{
    struct at91_cf_socket   *cf = platform_get_drvdata(pdev);
    struct at91_cf_data *board = cf->board;

    if (device_may_wakeup(&pdev->dev)) {
        enable_irq_wake(gpio_to_irq(board->det_pin));
        if (gpio_is_valid(board->irq_pin))
            enable_irq_wake(gpio_to_irq(board->irq_pin));
    }
    return 0;
}

static int at91_cf_resume(struct platform_device *pdev)
{
    struct at91_cf_socket   *cf = platform_get_drvdata(pdev);
    struct at91_cf_data *board = cf->board;

    if (device_may_wakeup(&pdev->dev)) {
        disable_irq_wake(gpio_to_irq(board->det_pin));
        if (gpio_is_valid(board->irq_pin))
            disable_irq_wake(gpio_to_irq(board->irq_pin));
    }

    return 0;
}

#else
#define at91_cf_suspend     NULL
#define at91_cf_resume      NULL
#endif

static struct platform_driver at91_cf_driver = {
    .driver = {
        .name       = (char *) driver_name,
        .owner      = THIS_MODULE,
    },
    .remove     = __exit_p(at91_cf_remove),
    .suspend    = at91_cf_suspend,
    .resume     = at91_cf_resume,
};

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

static int __init at91_cf_init(void)
{
    return platform_driver_probe(&at91_cf_driver, at91_cf_probe);
}
module_init(at91_cf_init);

static void __exit at91_cf_exit(void)
{
    platform_driver_unregister(&at91_cf_driver);
}
module_exit(at91_cf_exit);

MODULE_DESCRIPTION("AT91 Compact Flash Driver");
MODULE_AUTHOR("David Brownell");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:at91_cf");