/*
 *  ata_k2.c - Broadcom (Apple K2) SATA
 *
 *  Copyright 2003 Benjamin Herrenschmidt <benh@kernel.crashing.org>
 *
 *  Bits from Jeff Garzik, Copyright RedHat, Inc.
 *
 *  This driver probably works with non-Apple versions of the
 *  Broadcom chipset...
 *
 *  The contents of this file are subject to the Open
 *  Software License version 1.1 that can be found at
 *  http://www.opensource.org/licenses/osl-1.1.txt and is included herein
 *  by reference.
 *
 *  Alternatively, the contents of this file may be used under the terms
 *  of the GNU General Public License version 2 (the "GPL") as distributed
 *  in the kernel source COPYING file, in which case the provisions of
 *  the GPL are applicable instead of the above.  If you wish to allow
 *  the use of your version of this file only under the terms of the
 *  GPL and not to allow others to use your version of this file under
 *  the OSL, indicate your decision by deleting the provisions above and
 *  replace them with the notice and other provisions required by the GPL.
 *  If you do not delete the provisions above, a recipient may use your
 *  version of this file under either the OSL or the GPL.
 *
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include "scsi.h"
#include "hosts.h"
#include <linux/libata.h>

#ifdef CONFIG_ALL_PPC
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#endif /* CONFIG_ALL_PPC */

#define DRV_NAME        "ata_k2"
#define DRV_VERSION     "1.03"


static u32 k2_sata_scr_read (struct ata_port *ap, unsigned int sc_reg)
{
        if (sc_reg > SCR_CONTROL)
                return 0xffffffffU;
        return readl((void *) ap->ioaddr.scr_addr + (sc_reg * 4));
}


static void k2_sata_scr_write (struct ata_port *ap, unsigned int sc_reg,
                               u32 val)
{
        if (sc_reg > SCR_CONTROL)
                return;
        writel(val, (void *) ap->ioaddr.scr_addr + (sc_reg * 4));
}


static void k2_sata_tf_load(struct ata_port *ap, struct ata_taskfile *tf)
{
        struct ata_ioports *ioaddr = &ap->ioaddr;
        unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;

        if (tf->ctl != ap->last_ctl) {
                writeb(tf->ctl, ioaddr->ctl_addr);
                ap->last_ctl = tf->ctl;
                ata_wait_idle(ap);
        }
        if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
                writew(tf->feature | (((u16)tf->hob_feature) << 8), ioaddr->error_addr);
                writew(tf->nsect | (((u16)tf->hob_nsect) << 8), ioaddr->nsect_addr);
                writew(tf->lbal | (((u16)tf->hob_lbal) << 8), ioaddr->lbal_addr);
                writew(tf->lbam | (((u16)tf->hob_lbam) << 8), ioaddr->lbam_addr);
                writew(tf->lbah | (((u16)tf->hob_lbah) << 8), ioaddr->lbah_addr);
        } else if (is_addr) {
                writew(tf->feature, ioaddr->error_addr);
                writew(tf->nsect, ioaddr->nsect_addr);
                writew(tf->lbal, ioaddr->lbal_addr);
                writew(tf->lbam, ioaddr->lbam_addr);
                writew(tf->lbah, ioaddr->lbah_addr);
        }

        if (tf->flags & ATA_TFLAG_DEVICE)
                writeb(tf->device, ioaddr->device_addr);

        ata_wait_idle(ap);
}


static void k2_sata_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
{
        struct ata_ioports *ioaddr = &ap->ioaddr;
        u16 nsect, lbal, lbam, lbah;

        nsect = tf->nsect = readw(ioaddr->nsect_addr);
        lbal = tf->lbal = readw(ioaddr->lbal_addr);
        lbam = tf->lbam = readw(ioaddr->lbam_addr);
        lbah = tf->lbah = readw(ioaddr->lbah_addr);
        tf->device = readw(ioaddr->device_addr);

        if (tf->flags & ATA_TFLAG_LBA48) {
                tf->hob_feature = readw(ioaddr->error_addr) >> 8;
                tf->hob_nsect = nsect >> 8;
                tf->hob_lbal = lbal >> 8;
                tf->hob_lbam = lbam >> 8;
                tf->hob_lbah = lbah >> 8;
        }
}


static u8 k2_stat_check_status(struct ata_port *ap)
{
        return readl((void *) ap->ioaddr.cmdstat_addr);
}

static void k2_sata_set_piomode (struct ata_port *ap, struct ata_device *adev,
                              unsigned int pio)
{
        /* We need empty implementation, the core doesn't test for NULL
         * function pointer
         */
}


static void k2_sata_set_udmamode (struct ata_port *ap, struct ata_device *adev,
                              unsigned int udma)
{
        /* We need empty implementation, the core doesn't test for NULL
         * function pointer
         */
}


#ifdef CONFIG_ALL_PPC
/*
 * k2_sata_proc_info
 * inout : decides on the direction of the dataflow and the meaning of the
 *         variables
 * buffer: If inout==FALSE data is being written to it else read from it
 * *start: If inout==FALSE start of the valid data in the buffer
 * offset: If inout==FALSE offset from the beginning of the imaginary file
 *         from which we start writing into the buffer
 * length: If inout==FALSE max number of bytes to be written into the buffer
 *         else number of bytes in the buffer
 */
static int k2_sata_proc_info(char *page, char **start, off_t offset, int count,
                   int hostno, int inout)
{
        struct Scsi_Host *hpnt;
        struct ata_port *ap;
        struct device_node *np;
        int len, index;

        /* Find ourself. That's locking-broken, shitty etc... but thanks to
         * /proc/scsi interface and lack of state kept around in this driver,
         * its best I want to do for now...
         */
        hpnt = scsi_hostlist;
        while (hpnt) {
                if (hostno == hpnt->host_no)
                        break;
                hpnt = hpnt->next;
        }
        if (!hpnt)
                return 0;

        /* Find  the ata_port */
        ap = (struct ata_port *) &hpnt->hostdata[0];
        if (ap == NULL)
                return 0;

        /* Find the OF node for the PCI device proper */
        np = pci_device_to_OF_node(ap->host_set->pdev);
        if (np == NULL)
                return 0;

        /* Match it to a port node */
        index = (ap == ap->host_set->ports[0]) ? 0 : 1;
        for (np = np->child; np != NULL; np = np->sibling) {
                u32 *reg = (u32 *)get_property(np, "reg", NULL);
                if (!reg)
                        continue;
                if (index == *reg)
                        break;
        }
        if (np == NULL)
                return 0;

        len = sprintf(page, "devspec: %s\n", np->full_name);

        return len;
}
#endif /* CONFIG_ALL_PPC */


static Scsi_Host_Template k2_sata_sht = {
        .module                 = THIS_MODULE,
        .name                   = DRV_NAME,
        .queuecommand           = ata_scsi_queuecmd,
        .eh_strategy_handler    = ata_scsi_error,
        .can_queue              = ATA_DEF_QUEUE,
        .this_id                = ATA_SHT_THIS_ID,
        .sg_tablesize           = ATA_MAX_PRD,
        .max_sectors            = ATA_MAX_SECTORS,
        .cmd_per_lun            = ATA_SHT_CMD_PER_LUN,
        .emulated               = ATA_SHT_EMULATED,
        .use_clustering         = ATA_SHT_USE_CLUSTERING,
        .proc_name              = DRV_NAME,
        .dma_boundary           = ATA_DMA_BOUNDARY,
        .slave_configure        = ata_scsi_slave_config,
#ifdef CONFIG_ALL_PPC
        .proc_info              = k2_sata_proc_info
#endif
};


static struct ata_port_operations k2_sata_ops = {
        .port_disable           = ata_port_disable,
        .set_piomode            = k2_sata_set_piomode,
        .set_udmamode           = k2_sata_set_udmamode,
        .tf_load                = k2_sata_tf_load,
        .tf_read                = k2_sata_tf_read,
        .check_status           = k2_stat_check_status,
        .exec_command           = ata_exec_command_mmio,
        .phy_reset              = sata_phy_reset,
        .phy_config             = pata_phy_config,      /* not a typo */
        .bmdma_start            = ata_bmdma_start_mmio,
        .fill_sg                = ata_fill_sg,
        .eng_timeout            = ata_eng_timeout,
        .irq_handler            = ata_interrupt,
        .scr_read               = k2_sata_scr_read,
        .scr_write              = k2_sata_scr_write,
        .port_start             = ata_port_start,
        .port_stop              = ata_port_stop,
};


static void k2_sata_setup_port(struct ata_ioports *port, unsigned long base)
{
        port->cmd_addr = base;
        port->data_addr = base;
        port->error_addr = base + 0x4;
        port->nsect_addr = base + 0x8;
        port->lbal_addr = base + 0xc;
        port->lbam_addr = base + 0x10;
        port->lbah_addr = base + 0x14;
        port->device_addr = base + 0x18;
        port->cmdstat_addr = base + 0x1c;
        port->ctl_addr = base + 0x20;
        port->bmdma_addr = base + 0x30;
        port->scr_addr = base + 0x40;
}


static int k2_sata_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
{
        static int printed_version;
        struct ata_probe_ent *probe_ent = NULL;
        unsigned long base;
        void *mmio_base;
        int rc;

        if (!printed_version++)
                printk(KERN_DEBUG DRV_NAME " version " DRV_VERSION "\n");

        /*
         * If this driver happens to only be useful on Apple's K2, then
         * we should check that here as it has a normal Serverworks ID
         */
        rc = pci_enable_device(pdev);
        if (rc)
                return rc;

        rc = pci_request_regions(pdev, DRV_NAME);
        if (rc)
                goto err_out;

        rc = pci_set_dma_mask(pdev, ATA_DMA_MASK);
        if (rc)
                goto err_out_regions;

        probe_ent = kmalloc(sizeof(*probe_ent), GFP_KERNEL);
        if (probe_ent == NULL) {
                rc = -ENOMEM;
                goto err_out_regions;
        }

        memset(probe_ent, 0, sizeof(*probe_ent));
        probe_ent->pdev = pdev;
        INIT_LIST_HEAD(&probe_ent->node);

        mmio_base = ioremap(pci_resource_start(pdev, 5),
                            pci_resource_len(pdev, 5));
        if (mmio_base == NULL) {
                rc = -ENOMEM;
                goto err_out_free_ent;
        }
        base = (unsigned long) mmio_base;

        /*
         * Check for the "disabled" second function to avoid registering
         * useless interfaces on K2
         */
        if (readl(mmio_base + 0x40)  == 0xffffffffUL &&
            readl(mmio_base + 0x140) == 0xffffffffUL) {
                rc = -ENODEV;
                goto err_out_unmap;
        }

        /* Clear a magic bit in SCR1 according to Darwin, those help
         * some funky seagate drives (though so far, those were already
         * set by the firmware on the machines I had access to
         */
        writel(readl(mmio_base + 0x80) & ~0x00040000, mmio_base + 0x80);

        /* Clear SATA error & interrupts we don't use */
        writel(0xffffffff, mmio_base + 0x44);
        writel(0x0, mmio_base + 0x88);

        probe_ent->sht = &k2_sata_sht;
        probe_ent->host_flags = ATA_FLAG_SATA | ATA_FLAG_SATA_RESET |
                                ATA_FLAG_NO_LEGACY | ATA_FLAG_MMIO;
        probe_ent->port_ops = &k2_sata_ops;
        probe_ent->n_ports = 2;
        probe_ent->irq = pdev->irq;
        probe_ent->irq_flags = SA_SHIRQ;
        probe_ent->mmio_base = mmio_base;

        /*
         * We don't care much about the PIO/UDMA masks, but the core won't like us
         * if we don't fill these
         */
        probe_ent->pio_mask = 0x1f;
        probe_ent->udma_mask = 0x7f;

        k2_sata_setup_port(&probe_ent->port[0], base);
        k2_sata_setup_port(&probe_ent->port[1], base + 0x100);

        pci_set_master(pdev);

        /* FIXME: check ata_device_add return value */
        ata_device_add(probe_ent);
        kfree(probe_ent);

        return 0;

err_out_unmap:
        iounmap((void *)base);
err_out_free_ent:
        kfree(probe_ent);
err_out_regions:
        pci_release_regions(pdev);
err_out:
        pci_disable_device(pdev);
        return rc;
}


static struct pci_device_id k2_sata_pci_tbl[] = {
        { 0x1166, 0x0240, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
        { }
};


static struct pci_driver k2_sata_pci_driver = {
        .name                   = DRV_NAME,
        .id_table               = k2_sata_pci_tbl,
        .probe                  = k2_sata_init_one,
        .remove                 = ata_pci_remove_one,
};


static int __init k2_sata_init(void)
{
        int rc;

        rc = pci_module_init(&k2_sata_pci_driver);
        if (rc)
                return rc;

        return 0;
}


static void __exit k2_sata_exit(void)
{
        pci_unregister_driver(&k2_sata_pci_driver);
}


MODULE_AUTHOR("Benjamin Herrenschmidt");
MODULE_DESCRIPTION("low-level driver for K2 SATA controller");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, k2_sata_pci_tbl);

module_init(k2_sata_init);
module_exit(k2_sata_exit);