/*
 * Generic platform device PATA driver
 *
 * Copyright (C) 2006 - 2007  Paul Mundt
 *
 * Based on pata_pcmcia:
 *
 *   Copyright 2005-2006 Red Hat Inc, all rights reserved.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <scsi/scsi_host.h>
#include <linux/ata.h>
#include <linux/libata.h>
#include <linux/platform_device.h>
#include <linux/ata_platform.h>

#define DRV_NAME "pata_platform"
#define DRV_VERSION "1.2"

static int pio_mask = 1;
module_param(pio_mask, int, 0);
MODULE_PARM_DESC(pio_mask, "PIO modes supported, mode 0 only by default");

/*
 * Provide our own set_mode() as we don't want to change anything that has
 * already been configured..
 */
static int pata_platform_set_mode(struct ata_link *link, struct ata_device **unused)
{
        struct ata_device *dev;

        ata_for_each_dev(dev, link, ENABLED) {
                /* We don't really care */
                dev->pio_mode = dev->xfer_mode = XFER_PIO_0;
                dev->xfer_shift = ATA_SHIFT_PIO;
                dev->flags |= ATA_DFLAG_PIO;
                ata_dev_info(dev, "configured for PIO\n");
        }
        return 0;
}

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

static void pata_platform_setup_port(struct ata_ioports *ioaddr,
                                     unsigned int shift)
{
        /* Fixup the port shift for platforms that need it */
        ioaddr->data_addr       = ioaddr->cmd_addr + (ATA_REG_DATA    << shift);
        ioaddr->error_addr      = ioaddr->cmd_addr + (ATA_REG_ERR     << shift);
        ioaddr->feature_addr    = ioaddr->cmd_addr + (ATA_REG_FEATURE << shift);
        ioaddr->nsect_addr      = ioaddr->cmd_addr + (ATA_REG_NSECT   << shift);
        ioaddr->lbal_addr       = ioaddr->cmd_addr + (ATA_REG_LBAL    << shift);
        ioaddr->lbam_addr       = ioaddr->cmd_addr + (ATA_REG_LBAM    << shift);
        ioaddr->lbah_addr       = ioaddr->cmd_addr + (ATA_REG_LBAH    << shift);
        ioaddr->device_addr     = ioaddr->cmd_addr + (ATA_REG_DEVICE  << shift);
        ioaddr->status_addr     = ioaddr->cmd_addr + (ATA_REG_STATUS  << shift);
        ioaddr->command_addr    = ioaddr->cmd_addr + (ATA_REG_CMD     << shift);
}

/**
 *      __pata_platform_probe           -       attach a platform interface
 *      @dev: device
 *      @io_res: Resource representing I/O base
 *      @ctl_res: Resource representing CTL base
 *      @irq_res: Resource representing IRQ and its flags
 *      @ioport_shift: I/O port shift
 *      @__pio_mask: PIO mask
 *      @sht: scsi_host_template to use when registering
 *      @use16bit: Flag to indicate 16-bit IO instead of 32-bit
 *
 *      Register a platform bus IDE interface. Such interfaces are PIO and we
 *      assume do not support IRQ sharing.
 *
 *      Platform devices are expected to contain at least 2 resources per port:
 *
 *              - I/O Base (IORESOURCE_IO or IORESOURCE_MEM)
 *              - CTL Base (IORESOURCE_IO or IORESOURCE_MEM)
 *
 *      and optionally:
 *
 *              - IRQ      (IORESOURCE_IRQ)
 *
 *      If the base resources are both mem types, the ioremap() is handled
 *      here. For IORESOURCE_IO, it's assumed that there's no remapping
 *      necessary.
 *
 *      If no IRQ resource is present, PIO polling mode is used instead.
 */
int __pata_platform_probe(struct device *dev, struct resource *io_res,
                          struct resource *ctl_res, struct resource *irq_res,
                          unsigned int ioport_shift, int __pio_mask,
                          const struct scsi_host_template *sht, bool use16bit)
{
        struct ata_host *host;
        struct ata_port *ap;
        unsigned int mmio;
        int irq = 0;
        int irq_flags = 0;

        /*
         * Check for MMIO
         */
        mmio = (( io_res->flags == IORESOURCE_MEM) &&
                (ctl_res->flags == IORESOURCE_MEM));

        /*
         * And the IRQ
         */
        if (irq_res && irq_res->start > 0) {
                irq = irq_res->start;
                irq_flags = (irq_res->flags & IRQF_TRIGGER_MASK) | IRQF_SHARED;
        }

        /*
         * Now that that's out of the way, wire up the port..
         */
        host = ata_host_alloc(dev, 1);
        if (!host)
                return -ENOMEM;
        ap = host->ports[0];

        ap->ops = devm_kzalloc(dev, sizeof(*ap->ops), GFP_KERNEL);
        if (!ap->ops)
                return -ENOMEM;
        ap->ops->inherits = &ata_sff_port_ops;
        ap->ops->cable_detect = ata_cable_unknown;
        ap->ops->set_mode = pata_platform_set_mode;
        if (use16bit)
                ap->ops->sff_data_xfer = ata_sff_data_xfer;
        else
                ap->ops->sff_data_xfer = ata_sff_data_xfer32;

        ap->pio_mask = __pio_mask;
        ap->flags |= ATA_FLAG_SLAVE_POSS;

        /*
         * Use polling mode if there's no IRQ
         */
        if (!irq) {
                ap->flags |= ATA_FLAG_PIO_POLLING;
                ata_port_desc(ap, "no IRQ, using PIO polling");
        }

        /*
         * Handle the MMIO case
         */
        if (mmio) {
                ap->ioaddr.cmd_addr = devm_ioremap(dev, io_res->start,
                                resource_size(io_res));
                ap->ioaddr.ctl_addr = devm_ioremap(dev, ctl_res->start,
                                resource_size(ctl_res));
        } else {
                ap->ioaddr.cmd_addr = devm_ioport_map(dev, io_res->start,
                                resource_size(io_res));
                ap->ioaddr.ctl_addr = devm_ioport_map(dev, ctl_res->start,
                                resource_size(ctl_res));
        }
        if (!ap->ioaddr.cmd_addr || !ap->ioaddr.ctl_addr) {
                dev_err(dev, "failed to map IO/CTL base\n");
                return -ENOMEM;
        }

        ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;

        pata_platform_setup_port(&ap->ioaddr, ioport_shift);

        ata_port_desc(ap, "%s cmd 0x%llx ctl 0x%llx", mmio ? "mmio" : "ioport",
                      (unsigned long long)io_res->start,
                      (unsigned long long)ctl_res->start);

        /* activate */
        return ata_host_activate(host, irq, irq ? ata_sff_interrupt : NULL,
                                 irq_flags, sht);
}
EXPORT_SYMBOL_GPL(__pata_platform_probe);

static int pata_platform_probe(struct platform_device *pdev)
{
        struct resource *io_res;
        struct resource *ctl_res;
        struct resource *irq_res;
        struct pata_platform_info *pp_info = dev_get_platdata(&pdev->dev);

        /*
         * Simple resource validation ..
         */
        if ((pdev->num_resources != 3) && (pdev->num_resources != 2)) {
                dev_err(&pdev->dev, "invalid number of resources\n");
                return -EINVAL;
        }

        /*
         * Get the I/O base first
         */
        io_res = platform_get_mem_or_io(pdev, 0);
        if (!io_res)
                return -EINVAL;

        /*
         * Then the CTL base
         */
        ctl_res = platform_get_mem_or_io(pdev, 1);
        if (!ctl_res)
                return -EINVAL;

        /*
         * And the IRQ
         */
        irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);

        return __pata_platform_probe(&pdev->dev, io_res, ctl_res, irq_res,
                                     pp_info ? pp_info->ioport_shift : 0,
                                     pio_mask, &pata_platform_sht, false);
}

static struct platform_driver pata_platform_driver = {
        .probe          = pata_platform_probe,
        .remove         = ata_platform_remove_one,
        .driver = {
                .name           = DRV_NAME,
        },
};

module_platform_driver(pata_platform_driver);

MODULE_AUTHOR("Paul Mundt");
MODULE_DESCRIPTION("low-level driver for platform device ATA");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
MODULE_ALIAS("platform:" DRV_NAME);