// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/acorn/scsi/cumana_2.c
 *
 *  Copyright (C) 1997-2005 Russell King
 *
 *  Changelog:
 *   30-08-1997 RMK     0.0.0   Created, READONLY version.
 *   22-01-1998 RMK     0.0.1   Updated to 2.1.80.
 *   15-04-1998 RMK     0.0.1   Only do PIO if FAS216 will allow it.
 *   02-05-1998 RMK     0.0.2   Updated & added DMA support.
 *   27-06-1998 RMK             Changed asm/delay.h to linux/delay.h
 *   18-08-1998 RMK     0.0.3   Fixed synchronous transfer depth.
 *   02-04-2000 RMK     0.0.4   Updated for new error handling code.
 */
#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 CUMANASCSI2_STATUS              (0x0000)
#define STATUS_INT                      (1 << 0)
#define STATUS_DRQ                      (1 << 1)
#define STATUS_LATCHED                  (1 << 3)

#define CUMANASCSI2_ALATCH              (0x0014)
#define ALATCH_ENA_INT                  (3)
#define ALATCH_DIS_INT                  (2)
#define ALATCH_ENA_TERM                 (5)
#define ALATCH_DIS_TERM                 (4)
#define ALATCH_ENA_BIT32                (11)
#define ALATCH_DIS_BIT32                (10)
#define ALATCH_ENA_DMA                  (13)
#define ALATCH_DIS_DMA                  (12)
#define ALATCH_DMA_OUT                  (15)
#define ALATCH_DMA_IN                   (14)

#define CUMANASCSI2_PSEUDODMA           (0x0200)

#define CUMANASCSI2_FAS216_OFFSET       (0x0300)
#define CUMANASCSI2_FAS216_SHIFT        2

/*
 * Version
 */
#define VERSION "1.00 (13/11/2002 2.5.47)"

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

#define NR_SG   256

struct cumanascsi2_info {
        FAS216_Info             info;
        struct expansion_card   *ec;
        void __iomem            *base;
        unsigned int            terms;          /* Terminator state     */
        struct scatterlist      sg[NR_SG];      /* Scatter DMA list     */
};

#define CSTATUS_IRQ     (1 << 0)
#define CSTATUS_DRQ     (1 << 1)

/* Prototype: void cumanascsi_2_irqenable(ec, irqnr)
 * Purpose  : Enable interrupts on Cumana SCSI 2 card
 * Params   : ec    - expansion card structure
 *          : irqnr - interrupt number
 */
static void
cumanascsi_2_irqenable(struct expansion_card *ec, int irqnr)
{
        struct cumanascsi2_info *info = ec->irq_data;
        writeb(ALATCH_ENA_INT, info->base + CUMANASCSI2_ALATCH);
}

/* Prototype: void cumanascsi_2_irqdisable(ec, irqnr)
 * Purpose  : Disable interrupts on Cumana SCSI 2 card
 * Params   : ec    - expansion card structure
 *          : irqnr - interrupt number
 */
static void
cumanascsi_2_irqdisable(struct expansion_card *ec, int irqnr)
{
        struct cumanascsi2_info *info = ec->irq_data;
        writeb(ALATCH_DIS_INT, info->base + CUMANASCSI2_ALATCH);
}

static const expansioncard_ops_t cumanascsi_2_ops = {
        .irqenable      = cumanascsi_2_irqenable,
        .irqdisable     = cumanascsi_2_irqdisable,
};

/* Prototype: void cumanascsi_2_terminator_ctl(host, on_off)
 * Purpose  : Turn the Cumana SCSI 2 terminators on or off
 * Params   : host   - card to turn on/off
 *          : on_off - !0 to turn on, 0 to turn off
 */
static void
cumanascsi_2_terminator_ctl(struct Scsi_Host *host, int on_off)
{
        struct cumanascsi2_info *info = (struct cumanascsi2_info *)host->hostdata;

        if (on_off) {
                info->terms = 1;
                writeb(ALATCH_ENA_TERM, info->base + CUMANASCSI2_ALATCH);
        } else {
                info->terms = 0;
                writeb(ALATCH_DIS_TERM, info->base + CUMANASCSI2_ALATCH);
        }
}

/* Prototype: void cumanascsi_2_intr(irq, *dev_id, *regs)
 * Purpose  : handle interrupts from Cumana SCSI 2 card
 * Params   : irq    - interrupt number
 *            dev_id - user-defined (Scsi_Host structure)
 */
static irqreturn_t
cumanascsi_2_intr(int irq, void *dev_id)
{
        struct cumanascsi2_info *info = dev_id;

        return fas216_intr(&info->info);
}

/* Prototype: fasdmatype_t cumanascsi_2_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
cumanascsi_2_dma_setup(struct Scsi_Host *host, struct scsi_pointer *SCp,
                       fasdmadir_t direction, fasdmatype_t min_type)
{
        struct cumanascsi2_info *info = (struct cumanascsi2_info *)host->hostdata;
        struct device *dev = scsi_get_device(host);
        int dmach = info->info.scsi.dma;

        writeb(ALATCH_DIS_DMA, info->base + CUMANASCSI2_ALATCH);

        if (dmach != NO_DMA &&
            (min_type == fasdma_real_all || SCp->this_residual >= 512)) {
                int bufs, map_dir, dma_dir, alatch_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;
                        alatch_dir = ALATCH_DMA_OUT;
                } else {
                        map_dir = DMA_FROM_DEVICE;
                        dma_dir = DMA_MODE_READ;
                        alatch_dir = ALATCH_DMA_IN;
                }

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

                disable_dma(dmach);
                set_dma_sg(dmach, info->sg, bufs);
                writeb(alatch_dir, info->base + CUMANASCSI2_ALATCH);
                set_dma_mode(dmach, dma_dir);
                enable_dma(dmach);
                writeb(ALATCH_ENA_DMA, info->base + CUMANASCSI2_ALATCH);
                writeb(ALATCH_DIS_BIT32, info->base + CUMANASCSI2_ALATCH);
                return fasdma_real_all;
        }

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

/*
 * Prototype: void cumanascsi_2_dma_pseudo(host, SCpnt, direction, transfer)
 * Purpose  : handles pseudo DMA
 * Params   : host      - host
 *            SCpnt     - command
 *            direction - DMA on to/off of card
 *            transfer  - minimum number of bytes we expect to transfer
 */
static void
cumanascsi_2_dma_pseudo(struct Scsi_Host *host, struct scsi_pointer *SCp,
                        fasdmadir_t direction, int transfer)
{
        struct cumanascsi2_info *info = (struct cumanascsi2_info *)host->hostdata;
        unsigned int length;
        unsigned char *addr;

        length = SCp->this_residual;
        addr = SCp->ptr;

        if (direction == DMA_OUT)
#if 0
                while (length > 1) {
                        unsigned long word;
                        unsigned int status = readb(info->base + CUMANASCSI2_STATUS);

                        if (status & STATUS_INT)
                                goto end;

                        if (!(status & STATUS_DRQ))
                                continue;

                        word = *addr | *(addr + 1) << 8;
                        writew(word, info->base + CUMANASCSI2_PSEUDODMA);
                        addr += 2;
                        length -= 2;
                }
#else
                printk ("PSEUDO_OUT???\n");
#endif
        else {
                if (transfer && (transfer & 255)) {
                        while (length >= 256) {
                                unsigned int status = readb(info->base + CUMANASCSI2_STATUS);

                                if (status & STATUS_INT)
                                        return;
            
                                if (!(status & STATUS_DRQ))
                                        continue;

                                readsw(info->base + CUMANASCSI2_PSEUDODMA,
                                       addr, 256 >> 1);
                                addr += 256;
                                length -= 256;
                        }
                }

                while (length > 0) {
                        unsigned long word;
                        unsigned int status = readb(info->base + CUMANASCSI2_STATUS);

                        if (status & STATUS_INT)
                                return;

                        if (!(status & STATUS_DRQ))
                                continue;

                        word = readw(info->base + CUMANASCSI2_PSEUDODMA);
                        *addr++ = word;
                        if (--length > 0) {
                                *addr++ = word >> 8;
                                length --;
                        }
                }
        }
}

/* Prototype: int cumanascsi_2_dma_stop(host, SCpnt)
 * Purpose  : stops DMA/PIO
 * Params   : host  - host
 *            SCpnt - command
 */
static void
cumanascsi_2_dma_stop(struct Scsi_Host *host, struct scsi_pointer *SCp)
{
        struct cumanascsi2_info *info = (struct cumanascsi2_info *)host->hostdata;
        if (info->info.scsi.dma != NO_DMA) {
                writeb(ALATCH_DIS_DMA, info->base + CUMANASCSI2_ALATCH);
                disable_dma(info->info.scsi.dma);
        }
}

/* Prototype: const char *cumanascsi_2_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 *cumanascsi_2_info(struct Scsi_Host *host)
{
        struct cumanascsi2_info *info = (struct cumanascsi2_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->terms ? "n" : "ff");

        return string;
}

/* Prototype: int cumanascsi_2_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
cumanascsi_2_set_proc_info(struct Scsi_Host *host, char *buffer, int length)
{
        int ret = length;

        if (length >= 11 && strncmp(buffer, "CUMANASCSI2", 11) == 0) {
                buffer += 11;
                length -= 11;

                if (length >= 5 && strncmp(buffer, "term=", 5) == 0) {
                        if (buffer[5] == '1')
                                cumanascsi_2_terminator_ctl(host, 1);
                        else if (buffer[5] == '0')
                                cumanascsi_2_terminator_ctl(host, 0);
                        else
                                ret = -EINVAL;
                } else {
                        ret = -EINVAL;
                }
        } else {
                ret = -EINVAL;
        }

        return ret;
}

static int cumanascsi_2_show_info(struct seq_file *m, struct Scsi_Host *host)
{
        struct cumanascsi2_info *info;
        info = (struct cumanascsi2_info *)host->hostdata;

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

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

static const struct scsi_host_template cumanascsi2_template = {
        .module                         = THIS_MODULE,
        .show_info                      = cumanascsi_2_show_info,
        .write_info                     = cumanascsi_2_set_proc_info,
        .name                           = "Cumana SCSI II",
        .info                           = cumanascsi_2_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                      = 1,
        .this_id                        = 7,
        .sg_tablesize                   = SG_MAX_SEGMENTS,
        .dma_boundary                   = IOMD_DMA_BOUNDARY,
        .proc_name                      = "cumanascsi2",
};

static int cumanascsi2_probe(struct expansion_card *ec,
                             const struct ecard_id *id)
{
        struct Scsi_Host *host;
        struct cumanascsi2_info *info;
        void __iomem *base;
        int ret;

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

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

        host = scsi_host_alloc(&cumanascsi2_template,
                               sizeof(struct cumanascsi2_info));
        if (!host) {
                ret = -ENOMEM;
                goto out_region;
        }

        ecard_set_drvdata(ec, host);

        info = (struct cumanascsi2_info *)host->hostdata;
        info->ec        = ec;
        info->base      = base;

        cumanascsi_2_terminator_ctl(host, term[ec->slot_no]);

        info->info.scsi.io_base         = base + CUMANASCSI2_FAS216_OFFSET;
        info->info.scsi.io_shift        = CUMANASCSI2_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   = FASCAP_PSEUDODMA;
        info->info.dma.setup            = cumanascsi_2_dma_setup;
        info->info.dma.pseudo           = cumanascsi_2_dma_pseudo;
        info->info.dma.stop             = cumanascsi_2_dma_stop;

        ec->irqaddr     = info->base + CUMANASCSI2_STATUS;
        ec->irqmask     = STATUS_INT;

        ecard_setirq(ec, &cumanascsi_2_ops, info);

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

        ret = request_irq(ec->irq, cumanascsi_2_intr,
                          0, "cumanascsi2", 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, "cumanascsi2")) {
                        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:
        scsi_host_put(host);

 out_region:
        ecard_release_resources(ec);

 out:
        return ret;
}

static void cumanascsi2_remove(struct expansion_card *ec)
{
        struct Scsi_Host *host = ecard_get_drvdata(ec);
        struct cumanascsi2_info *info = (struct cumanascsi2_info *)host->hostdata;

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

        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 cumanascsi2_cids[] = {
        { MANU_CUMANA, PROD_CUMANA_SCSI_2 },
        { 0xffff, 0xffff },
};

static struct ecard_driver cumanascsi2_driver = {
        .probe          = cumanascsi2_probe,
        .remove         = cumanascsi2_remove,
        .id_table       = cumanascsi2_cids,
        .drv = {
                .name           = "cumanascsi2",
        },
};

static int __init cumanascsi2_init(void)
{
        return ecard_register_driver(&cumanascsi2_driver);
}

static void __exit cumanascsi2_exit(void)
{
        ecard_remove_driver(&cumanascsi2_driver);
}

module_init(cumanascsi2_init);
module_exit(cumanascsi2_exit);

MODULE_AUTHOR("Russell King");
MODULE_DESCRIPTION("Cumana SCSI-2 driver for Acorn machines");
module_param_array(term, int, NULL, 0);
MODULE_PARM_DESC(term, "SCSI bus termination");
MODULE_LICENSE("GPL");