pata_rb532_cf.c

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/*
 *  A low-level PATA driver to handle a Compact Flash connected on the
 *  Mikrotik's RouterBoard 532 board.
 *
 *  Copyright (C) 2007 Gabor Juhos <juhosg at openwrt.org>
 *  Copyright (C) 2008 Florian Fainelli <[email protected]>
 *
 *  This file was based on: drivers/ata/pata_ixp4xx_cf.c
 *  Copyright (C) 2006-07 Tower Technologies
 *  Author: Alessandro Zummo <[email protected]>
 *
 *  Also was based on the driver for Linux 2.4.xx published by Mikrotik for
 *  their RouterBoard 1xx and 5xx series devices. The original Mikrotik code
 *  seems not to have a license.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 */

#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>

#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/irq.h>

#include <linux/libata.h>
#include <scsi/scsi_host.h>

#include <asm/gpio.h>

#define DRV_NAME    "pata-rb532-cf"
#define DRV_VERSION "0.1.0"
#define DRV_DESC    "PATA driver for RouterBOARD 532 Compact Flash"

#define RB500_CF_MAXPORTS   1
#define RB500_CF_IO_DELAY   400

#define RB500_CF_REG_BASE   0x0800
#define RB500_CF_REG_ERR    0x080D
#define RB500_CF_REG_CTRL   0x080E
/* 32bit buffered data register offset */
#define RB500_CF_REG_DBUF32 0x0C00

struct rb532_cf_info {
    void __iomem    *iobase;
    unsigned int    gpio_line;
    unsigned int    irq;
};

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

static irqreturn_t rb532_pata_irq_handler(int irq, void *dev_instance)
{
    struct ata_host *ah = dev_instance;
    struct rb532_cf_info *info = ah->private_data;

    if (gpio_get_value(info->gpio_line)) {
        irq_set_irq_type(info->irq, IRQ_TYPE_LEVEL_LOW);
        ata_sff_interrupt(info->irq, dev_instance);
    } else {
        irq_set_irq_type(info->irq, IRQ_TYPE_LEVEL_HIGH);
    }

    return IRQ_HANDLED;
}

static struct ata_port_operations rb532_pata_port_ops = {
    .inherits       = &ata_sff_port_ops,
    .sff_data_xfer      = ata_sff_data_xfer32,
};

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

static struct scsi_host_template rb532_pata_sht = {
    ATA_PIO_SHT(DRV_NAME),
};

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

static void rb532_pata_setup_ports(struct ata_host *ah)
{
    struct rb532_cf_info *info = ah->private_data;
    struct ata_port *ap;

    ap = ah->ports[0];

    ap->ops     = &rb532_pata_port_ops;
    ap->pio_mask    = ATA_PIO4;

    ap->ioaddr.cmd_addr = info->iobase + RB500_CF_REG_BASE;
    ap->ioaddr.ctl_addr = info->iobase + RB500_CF_REG_CTRL;
    ap->ioaddr.altstatus_addr = info->iobase + RB500_CF_REG_CTRL;

    ata_sff_std_ports(&ap->ioaddr);

    ap->ioaddr.data_addr    = info->iobase + RB500_CF_REG_DBUF32;
    ap->ioaddr.error_addr   = info->iobase + RB500_CF_REG_ERR;
}

static __devinit int rb532_pata_driver_probe(struct platform_device *pdev)
{
    int irq;
    int gpio;
    struct resource *res;
    struct ata_host *ah;
    struct rb532_cf_info *info;
    int ret;

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res) {
        dev_err(&pdev->dev, "no IOMEM resource found\n");
        return -EINVAL;
    }

    irq = platform_get_irq(pdev, 0);
    if (irq <= 0) {
        dev_err(&pdev->dev, "no IRQ resource found\n");
        return -ENOENT;
    }

    gpio = irq_to_gpio(irq);
    if (gpio < 0) {
        dev_err(&pdev->dev, "no GPIO found for irq%d\n", irq);
        return -ENOENT;
    }

    ret = gpio_request(gpio, DRV_NAME);
    if (ret) {
        dev_err(&pdev->dev, "GPIO request failed\n");
        return ret;
    }

    /* allocate host */
    ah = ata_host_alloc(&pdev->dev, RB500_CF_MAXPORTS);
    if (!ah)
        return -ENOMEM;

    platform_set_drvdata(pdev, ah);

    info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
    if (!info)
        return -ENOMEM;

    ah->private_data = info;
    info->gpio_line = gpio;
    info->irq = irq;

    info->iobase = devm_ioremap_nocache(&pdev->dev, res->start,
                resource_size(res));
    if (!info->iobase)
        return -ENOMEM;

    ret = gpio_direction_input(gpio);
    if (ret) {
        dev_err(&pdev->dev, "unable to set GPIO direction, err=%d\n",
                ret);
        goto err_free_gpio;
    }

    rb532_pata_setup_ports(ah);

    ret = ata_host_activate(ah, irq, rb532_pata_irq_handler,
                IRQF_TRIGGER_LOW, &rb532_pata_sht);
    if (ret)
        goto err_free_gpio;

    return 0;

err_free_gpio:
    gpio_free(gpio);

    return ret;
}

static __devexit int rb532_pata_driver_remove(struct platform_device *pdev)
{
    struct ata_host *ah = platform_get_drvdata(pdev);
    struct rb532_cf_info *info = ah->private_data;

    ata_host_detach(ah);
    gpio_free(info->gpio_line);

    return 0;
}

static struct platform_driver rb532_pata_platform_driver = {
    .probe      = rb532_pata_driver_probe,
    .remove     = __devexit_p(rb532_pata_driver_remove),
    .driver  = {
        .name   = DRV_NAME,
        .owner  = THIS_MODULE,
    },
};

#define DRV_INFO DRV_DESC " version " DRV_VERSION

module_platform_driver(rb532_pata_platform_driver);

MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
MODULE_AUTHOR("Florian Fainelli <[email protected]>");
MODULE_DESCRIPTION(DRV_DESC);
MODULE_VERSION(DRV_VERSION);
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);