// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/acorn/scsi/powertec.c
 *
 *  Copyright (C) 1997-2005 Russell King
 */
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/dma-mapping.h>
#include <linux/pgtable.h>

#include <asm/dma.h>
#include <asm/ecard.h>
#include <asm/io.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
#include "fas216.h"
#include "arm_scsi.h"

#include <scsi/scsicam.h>

#define POWERTEC_FAS216_OFFSET  0x3000
#define POWERTEC_FAS216_SHIFT   6

#define POWERTEC_INTR_STATUS    0x2000
#define POWERTEC_INTR_BIT       0x80

#define POWERTEC_RESET_CONTROL  0x1018
#define POWERTEC_RESET_BIT      1

#define POWERTEC_TERM_CONTROL   0x2018
#define POWERTEC_TERM_ENABLE    1

#define POWERTEC_INTR_CONTROL   0x101c
#define POWERTEC_INTR_ENABLE    1
#define POWERTEC_INTR_DISABLE   0

#define VERSION "1.10 (19/01/2003 2.5.59)"

/*
 * Use term=0,1,0,0,0 to turn terminators on/off.
 * One entry per slot.
 */
static int term[MAX_ECARDS] = { 1, 1, 1, 1, 1, 1, 1, 1 };

#define NR_SG   256

struct powertec_info {
        FAS216_Info             info;
        struct expansion_card   *ec;
        void __iomem            *base;
        unsigned int            term_ctl;
        struct scatterlist      sg[NR_SG];
};

/* Prototype: void powertecscsi_irqenable(ec, irqnr)
 * Purpose  : Enable interrupts on Powertec SCSI card
 * Params   : ec    - expansion card structure
 *          : irqnr - interrupt number
 */
static void
powertecscsi_irqenable(struct expansion_card *ec, int irqnr)
{
        struct powertec_info *info = ec->irq_data;
        writeb(POWERTEC_INTR_ENABLE, info->base + POWERTEC_INTR_CONTROL);
}

/* Prototype: void powertecscsi_irqdisable(ec, irqnr)
 * Purpose  : Disable interrupts on Powertec SCSI card
 * Params   : ec    - expansion card structure
 *          : irqnr - interrupt number
 */
static void
powertecscsi_irqdisable(struct expansion_card *ec, int irqnr)
{
        struct powertec_info *info = ec->irq_data;
        writeb(POWERTEC_INTR_DISABLE, info->base + POWERTEC_INTR_CONTROL);
}

static const expansioncard_ops_t powertecscsi_ops = {
        .irqenable      = powertecscsi_irqenable,
        .irqdisable     = powertecscsi_irqdisable,
};

/* Prototype: void powertecscsi_terminator_ctl(host, on_off)
 * Purpose  : Turn the Powertec SCSI terminators on or off
 * Params   : host   - card to turn on/off
 *          : on_off - !0 to turn on, 0 to turn off
 */
static void
powertecscsi_terminator_ctl(struct Scsi_Host *host, int on_off)
{
        struct powertec_info *info = (struct powertec_info *)host->hostdata;

        info->term_ctl = on_off ? POWERTEC_TERM_ENABLE : 0;
        writeb(info->term_ctl, info->base + POWERTEC_TERM_CONTROL);
}

/* Prototype: void powertecscsi_intr(irq, *dev_id, *regs)
 * Purpose  : handle interrupts from Powertec SCSI card
 * Params   : irq    - interrupt number
 *            dev_id - user-defined (Scsi_Host structure)
 */
static irqreturn_t powertecscsi_intr(int irq, void *dev_id)
{
        struct powertec_info *info = dev_id;

        return fas216_intr(&info->info);
}

/* Prototype: fasdmatype_t powertecscsi_dma_setup(host, SCpnt, direction, min_type)
 * Purpose  : initialises DMA/PIO
 * Params   : host      - host
 *            SCpnt     - command
 *            direction - DMA on to/off of card
 *            min_type  - minimum DMA support that we must have for this transfer
 * Returns  : type of transfer to be performed
 */
static fasdmatype_t
powertecscsi_dma_setup(struct Scsi_Host *host, struct scsi_pointer *SCp,
                       fasdmadir_t direction, fasdmatype_t min_type)
{
        struct powertec_info *info = (struct powertec_info *)host->hostdata;
        struct device *dev = scsi_get_device(host);
        int dmach = info->info.scsi.dma;

        if (info->info.ifcfg.capabilities & FASCAP_DMA &&
            min_type == fasdma_real_all) {
                int bufs, map_dir, dma_dir;

                bufs = copy_SCp_to_sg(&info->sg[0], SCp, NR_SG);

                if (direction == DMA_OUT) {
                        map_dir = DMA_TO_DEVICE;
                        dma_dir = DMA_MODE_WRITE;
                } else {
                        map_dir = DMA_FROM_DEVICE;
                        dma_dir = DMA_MODE_READ;
                }

                dma_map_sg(dev, info->sg, bufs, map_dir);

                disable_dma(dmach);
                set_dma_sg(dmach, info->sg, bufs);
                set_dma_mode(dmach, dma_dir);
                enable_dma(dmach);
                return fasdma_real_all;
        }

        /*
         * If we're not doing DMA,
         *  we'll do slow PIO
         */
        return fasdma_pio;
}

/* Prototype: int powertecscsi_dma_stop(host, SCpnt)
 * Purpose  : stops DMA/PIO
 * Params   : host  - host
 *            SCpnt - command
 */
static void
powertecscsi_dma_stop(struct Scsi_Host *host, struct scsi_pointer *SCp)
{
        struct powertec_info *info = (struct powertec_info *)host->hostdata;
        if (info->info.scsi.dma != NO_DMA)
                disable_dma(info->info.scsi.dma);
}

/* Prototype: const char *powertecscsi_info(struct Scsi_Host * host)
 * Purpose  : returns a descriptive string about this interface,
 * Params   : host - driver host structure to return info for.
 * Returns  : pointer to a static buffer containing null terminated string.
 */
static const char *powertecscsi_info(struct Scsi_Host *host)
{
        struct powertec_info *info = (struct powertec_info *)host->hostdata;
        static char string[150];

        sprintf(string, "%s (%s) in slot %d v%s terminators o%s",
                host->hostt->name, info->info.scsi.type, info->ec->slot_no,
                VERSION, info->term_ctl ? "n" : "ff");

        return string;
}

/* Prototype: int powertecscsi_set_proc_info(struct Scsi_Host *host, char *buffer, int length)
 * Purpose  : Set a driver specific function
 * Params   : host   - host to setup
 *          : buffer - buffer containing string describing operation
 *          : length - length of string
 * Returns  : -EINVAL, or 0
 */
static int
powertecscsi_set_proc_info(struct Scsi_Host *host, char *buffer, int length)
{
        int ret = length;

        if (length >= 12 && strncmp(buffer, "POWERTECSCSI", 12) == 0) {
                buffer += 12;
                length -= 12;

                if (length >= 5 && strncmp(buffer, "term=", 5) == 0) {
                        if (buffer[5] == '1')
                                powertecscsi_terminator_ctl(host, 1);
                        else if (buffer[5] == '0')
                                powertecscsi_terminator_ctl(host, 0);
                        else
                                ret = -EINVAL;
                } else
                        ret = -EINVAL;
        } else
                ret = -EINVAL;

        return ret;
}

/* Prototype: int powertecscsi_proc_info(char *buffer, char **start, off_t offset,
 *                                      int length, int host_no, int inout)
 * Purpose  : Return information about the driver to a user process accessing
 *            the /proc filesystem.
 * Params   : buffer  - a buffer to write information to
 *            start   - a pointer into this buffer set by this routine to the start
 *                      of the required information.
 *            offset  - offset into information that we have read up to.
 *            length  - length of buffer
 *            inout   - 0 for reading, 1 for writing.
 * Returns  : length of data written to buffer.
 */
static int powertecscsi_show_info(struct seq_file *m, struct Scsi_Host *host)
{
        struct powertec_info *info;

        info = (struct powertec_info *)host->hostdata;

        seq_printf(m, "PowerTec SCSI driver v%s\n", VERSION);
        fas216_print_host(&info->info, m);
        seq_printf(m, "Term    : o%s\n",
                        info->term_ctl ? "n" : "ff");

        fas216_print_stats(&info->info, m);
        fas216_print_devices(&info->info, m);
        return 0;
}

static ssize_t powertecscsi_show_term(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct expansion_card *ec = ECARD_DEV(dev);
        struct Scsi_Host *host = ecard_get_drvdata(ec);
        struct powertec_info *info = (struct powertec_info *)host->hostdata;

        return sprintf(buf, "%d\n", info->term_ctl ? 1 : 0);
}

static ssize_t
powertecscsi_store_term(struct device *dev, struct device_attribute *attr, const char *buf, size_t len)
{
        struct expansion_card *ec = ECARD_DEV(dev);
        struct Scsi_Host *host = ecard_get_drvdata(ec);

        if (len > 1)
                powertecscsi_terminator_ctl(host, buf[0] != '0');

        return len;
}

static DEVICE_ATTR(bus_term, S_IRUGO | S_IWUSR,
                   powertecscsi_show_term, powertecscsi_store_term);

static const struct scsi_host_template powertecscsi_template = {
        .module                         = THIS_MODULE,
        .show_info                      = powertecscsi_show_info,
        .write_info                     = powertecscsi_set_proc_info,
        .name                           = "PowerTec SCSI",
        .info                           = powertecscsi_info,
        .queuecommand                   = fas216_queue_command,
        .eh_host_reset_handler          = fas216_eh_host_reset,
        .eh_bus_reset_handler           = fas216_eh_bus_reset,
        .eh_device_reset_handler        = fas216_eh_device_reset,
        .eh_abort_handler               = fas216_eh_abort,
        .cmd_size                       = sizeof(struct fas216_cmd_priv),
        .can_queue                      = 8,
        .this_id                        = 7,
        .sg_tablesize                   = SG_MAX_SEGMENTS,
        .dma_boundary                   = IOMD_DMA_BOUNDARY,
        .cmd_per_lun                    = 2,
        .proc_name                      = "powertec",
};

static int powertecscsi_probe(struct expansion_card *ec,
                              const struct ecard_id *id)
{
        struct Scsi_Host *host;
        struct powertec_info *info;
        void __iomem *base;
        int ret;

        ret = ecard_request_resources(ec);
        if (ret)
                goto out;

        base = ecardm_iomap(ec, ECARD_RES_IOCFAST, 0, 0);
        if (!base) {
                ret = -ENOMEM;
                goto out_region;
        }

        host = scsi_host_alloc(&powertecscsi_template,
                               sizeof (struct powertec_info));
        if (!host) {
                ret = -ENOMEM;
                goto out_region;
        }

        ecard_set_drvdata(ec, host);

        info = (struct powertec_info *)host->hostdata;
        info->base = base;
        powertecscsi_terminator_ctl(host, term[ec->slot_no]);

        info->ec = ec;
        info->info.scsi.io_base         = base + POWERTEC_FAS216_OFFSET;
        info->info.scsi.io_shift        = POWERTEC_FAS216_SHIFT;
        info->info.scsi.irq             = ec->irq;
        info->info.scsi.dma             = ec->dma;
        info->info.ifcfg.clockrate      = 40; /* MHz */
        info->info.ifcfg.select_timeout = 255;
        info->info.ifcfg.asyncperiod    = 200; /* ns */
        info->info.ifcfg.sync_max_depth = 7;
        info->info.ifcfg.cntl3          = CNTL3_BS8 | CNTL3_FASTSCSI | CNTL3_FASTCLK;
        info->info.ifcfg.disconnect_ok  = 1;
        info->info.ifcfg.wide_max_size  = 0;
        info->info.ifcfg.capabilities   = 0;
        info->info.dma.setup            = powertecscsi_dma_setup;
        info->info.dma.pseudo           = NULL;
        info->info.dma.stop             = powertecscsi_dma_stop;

        ec->irqaddr     = base + POWERTEC_INTR_STATUS;
        ec->irqmask     = POWERTEC_INTR_BIT;

        ecard_setirq(ec, &powertecscsi_ops, info);

        device_create_file(&ec->dev, &dev_attr_bus_term);

        ret = fas216_init(host);
        if (ret)
                goto out_free;

        ret = request_irq(ec->irq, powertecscsi_intr,
                          0, "powertec", info);
        if (ret) {
                printk("scsi%d: IRQ%d not free: %d\n",
                       host->host_no, ec->irq, ret);
                goto out_release;
        }

        if (info->info.scsi.dma != NO_DMA) {
                if (request_dma(info->info.scsi.dma, "powertec")) {
                        printk("scsi%d: DMA%d not free, using PIO\n",
                               host->host_no, info->info.scsi.dma);
                        info->info.scsi.dma = NO_DMA;
                } else {
                        set_dma_speed(info->info.scsi.dma, 180);
                        info->info.ifcfg.capabilities |= FASCAP_DMA;
                }
        }

        ret = fas216_add(host, &ec->dev);
        if (ret == 0)
                goto out;

        if (info->info.scsi.dma != NO_DMA)
                free_dma(info->info.scsi.dma);
        free_irq(ec->irq, info);

 out_release:
        fas216_release(host);

 out_free:
        device_remove_file(&ec->dev, &dev_attr_bus_term);
        scsi_host_put(host);

 out_region:
        ecard_release_resources(ec);

 out:
        return ret;
}

static void powertecscsi_remove(struct expansion_card *ec)
{
        struct Scsi_Host *host = ecard_get_drvdata(ec);
        struct powertec_info *info = (struct powertec_info *)host->hostdata;

        ecard_set_drvdata(ec, NULL);
        fas216_remove(host);

        device_remove_file(&ec->dev, &dev_attr_bus_term);

        if (info->info.scsi.dma != NO_DMA)
                free_dma(info->info.scsi.dma);
        free_irq(ec->irq, info);

        fas216_release(host);
        scsi_host_put(host);
        ecard_release_resources(ec);
}

static const struct ecard_id powertecscsi_cids[] = {
        { MANU_ALSYSTEMS, PROD_ALSYS_SCSIATAPI },
        { 0xffff, 0xffff },
};

static struct ecard_driver powertecscsi_driver = {
        .probe          = powertecscsi_probe,
        .remove         = powertecscsi_remove,
        .id_table       = powertecscsi_cids,
        .drv = {
                .name           = "powertecscsi",
        },
};

static int __init powertecscsi_init(void)
{
        return ecard_register_driver(&powertecscsi_driver);
}

static void __exit powertecscsi_exit(void)
{
        ecard_remove_driver(&powertecscsi_driver);
}

module_init(powertecscsi_init);
module_exit(powertecscsi_exit);

MODULE_AUTHOR("Russell King");
MODULE_DESCRIPTION("Powertec SCSI driver");
module_param_array(term, int, NULL, 0);
MODULE_PARM_DESC(term, "SCSI bus termination");
MODULE_LICENSE("GPL");