linux/drivers/scsi/sgiwd93.c
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   1/*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
   7 * Copyright (C) 1999 Andrew R. Baker (andrewb@uab.edu)
   8 * Copyright (C) 2001 Florian Lohoff (flo@rfc822.org)
   9 * Copyright (C) 2003, 07 Ralf Baechle (ralf@linux-mips.org)
  10 * 
  11 * (In all truth, Jed Schimmel wrote all this code.)
  12 */
  13
  14#undef DEBUG
  15
  16#include <linux/delay.h>
  17#include <linux/dma-mapping.h>
  18#include <linux/gfp.h>
  19#include <linux/interrupt.h>
  20#include <linux/init.h>
  21#include <linux/kernel.h>
  22#include <linux/types.h>
  23#include <linux/module.h>
  24#include <linux/platform_device.h>
  25#include <linux/spinlock.h>
  26
  27#include <asm/sgi/hpc3.h>
  28#include <asm/sgi/ip22.h>
  29#include <asm/sgi/wd.h>
  30
  31#include "scsi.h"
  32#include "wd33c93.h"
  33
  34struct ip22_hostdata {
  35        struct WD33C93_hostdata wh;
  36        dma_addr_t dma;
  37        void *cpu;
  38        struct device *dev;
  39};
  40
  41#define host_to_hostdata(host) ((struct ip22_hostdata *)((host)->hostdata))
  42
  43struct hpc_chunk {
  44        struct hpc_dma_desc desc;
  45        u32 _padding;   /* align to quadword boundary */
  46};
  47
  48/* space for hpc dma descriptors */
  49#define HPC_DMA_SIZE   PAGE_SIZE
  50
  51#define DMA_DIR(d)   ((d == DATA_OUT_DIR) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
  52
  53static irqreturn_t sgiwd93_intr(int irq, void *dev_id)
  54{
  55        struct Scsi_Host * host = dev_id;
  56        unsigned long flags;
  57
  58        spin_lock_irqsave(host->host_lock, flags);
  59        wd33c93_intr(host);
  60        spin_unlock_irqrestore(host->host_lock, flags);
  61
  62        return IRQ_HANDLED;
  63}
  64
  65static inline
  66void fill_hpc_entries(struct ip22_hostdata *hd, struct scsi_cmnd *cmd, int din)
  67{
  68        unsigned long len = cmd->SCp.this_residual;
  69        void *addr = cmd->SCp.ptr;
  70        dma_addr_t physaddr;
  71        unsigned long count;
  72        struct hpc_chunk *hcp;
  73
  74        physaddr = dma_map_single(hd->dev, addr, len, DMA_DIR(din));
  75        cmd->SCp.dma_handle = physaddr;
  76        hcp = hd->cpu;
  77
  78        while (len) {
  79                /*
  80                 * even cntinfo could be up to 16383, without
  81                 * magic only 8192 works correctly
  82                 */
  83                count = len > 8192 ? 8192 : len;
  84                hcp->desc.pbuf = physaddr;
  85                hcp->desc.cntinfo = count;
  86                hcp++;
  87                len -= count;
  88                physaddr += count;
  89        }
  90
  91        /*
  92         * To make sure, if we trip an HPC bug, that we transfer every single
  93         * byte, we tag on an extra zero length dma descriptor at the end of
  94         * the chain.
  95         */
  96        hcp->desc.pbuf = 0;
  97        hcp->desc.cntinfo = HPCDMA_EOX;
  98        dma_cache_sync(hd->dev, hd->cpu,
  99                       (unsigned long)(hcp + 1) - (unsigned long)hd->cpu,
 100                       DMA_TO_DEVICE);
 101}
 102
 103static int dma_setup(struct scsi_cmnd *cmd, int datainp)
 104{
 105        struct ip22_hostdata *hdata = host_to_hostdata(cmd->device->host);
 106        struct hpc3_scsiregs *hregs =
 107                (struct hpc3_scsiregs *) cmd->device->host->base;
 108
 109        pr_debug("dma_setup: datainp<%d> hcp<%p> ", datainp, hdata->cpu);
 110
 111        hdata->wh.dma_dir = datainp;
 112
 113        /*
 114         * wd33c93 shouldn't pass us bogus dma_setups, but it does:-(  The
 115         * other wd33c93 drivers deal with it the same way (which isn't that
 116         * obvious).  IMHO a better fix would be, not to do these dma setups
 117         * in the first place.
 118         */
 119        if (cmd->SCp.ptr == NULL || cmd->SCp.this_residual == 0)
 120                return 1;
 121
 122        fill_hpc_entries(hdata, cmd, datainp);
 123
 124        pr_debug(" HPCGO\n");
 125
 126        /* Start up the HPC. */
 127        hregs->ndptr = hdata->dma;
 128        if (datainp)
 129                hregs->ctrl = HPC3_SCTRL_ACTIVE;
 130        else
 131                hregs->ctrl = HPC3_SCTRL_ACTIVE | HPC3_SCTRL_DIR;
 132
 133        return 0;
 134}
 135
 136static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
 137                     int status)
 138{
 139        struct ip22_hostdata *hdata = host_to_hostdata(instance);
 140        struct hpc3_scsiregs *hregs;
 141
 142        if (!SCpnt)
 143                return;
 144
 145        if (SCpnt->SCp.ptr == NULL || SCpnt->SCp.this_residual == 0)
 146                return;
 147
 148        hregs = (struct hpc3_scsiregs *) SCpnt->device->host->base;
 149
 150        pr_debug("dma_stop: status<%d> ", status);
 151
 152        /* First stop the HPC and flush it's FIFO. */
 153        if (hdata->wh.dma_dir) {
 154                hregs->ctrl |= HPC3_SCTRL_FLUSH;
 155                while (hregs->ctrl & HPC3_SCTRL_ACTIVE)
 156                        barrier();
 157        }
 158        hregs->ctrl = 0;
 159        dma_unmap_single(hdata->dev, SCpnt->SCp.dma_handle,
 160                         SCpnt->SCp.this_residual,
 161                         DMA_DIR(hdata->wh.dma_dir));
 162
 163        pr_debug("\n");
 164}
 165
 166void sgiwd93_reset(unsigned long base)
 167{
 168        struct hpc3_scsiregs *hregs = (struct hpc3_scsiregs *) base;
 169
 170        hregs->ctrl = HPC3_SCTRL_CRESET;
 171        udelay(50);
 172        hregs->ctrl = 0;
 173}
 174EXPORT_SYMBOL_GPL(sgiwd93_reset);
 175
 176static inline void init_hpc_chain(struct ip22_hostdata *hdata)
 177{
 178        struct hpc_chunk *hcp = (struct hpc_chunk *)hdata->cpu;
 179        dma_addr_t dma = hdata->dma;
 180        unsigned long start, end;
 181
 182        start = (unsigned long) hcp;
 183        end = start + HPC_DMA_SIZE;
 184        while (start < end) {
 185                hcp->desc.pnext = (u32) (dma + sizeof(struct hpc_chunk));
 186                hcp->desc.cntinfo = HPCDMA_EOX;
 187                hcp++;
 188                dma += sizeof(struct hpc_chunk);
 189                start += sizeof(struct hpc_chunk);
 190        };
 191        hcp--;
 192        hcp->desc.pnext = hdata->dma;
 193}
 194
 195static int sgiwd93_bus_reset(struct scsi_cmnd *cmd)
 196{
 197        /* FIXME perform bus-specific reset */
 198
 199        /* FIXME 2: kill this function, and let midlayer fallback
 200           to the same result, calling wd33c93_host_reset() */
 201
 202        spin_lock_irq(cmd->device->host->host_lock);
 203        wd33c93_host_reset(cmd);
 204        spin_unlock_irq(cmd->device->host->host_lock);
 205
 206        return SUCCESS;
 207}
 208
 209/*
 210 * Kludge alert - the SCSI code calls the abort and reset method with int
 211 * arguments not with pointers.  So this is going to blow up beautyfully
 212 * on 64-bit systems with memory outside the compat address spaces.
 213 */
 214static struct scsi_host_template sgiwd93_template = {
 215        .module                 = THIS_MODULE,
 216        .proc_name              = "SGIWD93",
 217        .name                   = "SGI WD93",
 218        .queuecommand           = wd33c93_queuecommand,
 219        .eh_abort_handler       = wd33c93_abort,
 220        .eh_bus_reset_handler   = sgiwd93_bus_reset,
 221        .eh_host_reset_handler  = wd33c93_host_reset,
 222        .can_queue              = 16,
 223        .this_id                = 7,
 224        .sg_tablesize           = SG_ALL,
 225        .cmd_per_lun            = 8,
 226        .use_clustering         = DISABLE_CLUSTERING,
 227};
 228
 229static int __devinit sgiwd93_probe(struct platform_device *pdev)
 230{
 231        struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
 232        unsigned char *wdregs = pd->wdregs;
 233        struct hpc3_scsiregs *hregs = pd->hregs;
 234        struct ip22_hostdata *hdata;
 235        struct Scsi_Host *host;
 236        wd33c93_regs regs;
 237        unsigned int unit = pd->unit;
 238        unsigned int irq = pd->irq;
 239        int err;
 240
 241        host = scsi_host_alloc(&sgiwd93_template, sizeof(struct ip22_hostdata));
 242        if (!host) {
 243                err = -ENOMEM;
 244                goto out;
 245        }
 246
 247        host->base = (unsigned long) hregs;
 248        host->irq = irq;
 249
 250        hdata = host_to_hostdata(host);
 251        hdata->dev = &pdev->dev;
 252        hdata->cpu = dma_alloc_noncoherent(&pdev->dev, HPC_DMA_SIZE,
 253                                           &hdata->dma, GFP_KERNEL);
 254        if (!hdata->cpu) {
 255                printk(KERN_WARNING "sgiwd93: Could not allocate memory for "
 256                       "host %d buffer.\n", unit);
 257                err = -ENOMEM;
 258                goto out_put;
 259        }
 260
 261        init_hpc_chain(hdata);
 262
 263        regs.SASR = wdregs + 3;
 264        regs.SCMD = wdregs + 7;
 265
 266        hdata->wh.no_sync = 0;
 267        hdata->wh.fast = 1;
 268        hdata->wh.dma_mode = CTRL_BURST;
 269
 270        wd33c93_init(host, regs, dma_setup, dma_stop, WD33C93_FS_MHZ(20));
 271
 272        err = request_irq(irq, sgiwd93_intr, 0, "SGI WD93", host);
 273        if (err) {
 274                printk(KERN_WARNING "sgiwd93: Could not register irq %d "
 275                       "for host %d.\n", irq, unit);
 276                goto out_free;
 277        }
 278
 279        platform_set_drvdata(pdev, host);
 280
 281        err = scsi_add_host(host, NULL);
 282        if (err)
 283                goto out_irq;
 284
 285        scsi_scan_host(host);
 286
 287        return 0;
 288
 289out_irq:
 290        free_irq(irq, host);
 291out_free:
 292        dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma);
 293out_put:
 294        scsi_host_put(host);
 295out:
 296
 297        return err;
 298}
 299
 300static int __exit sgiwd93_remove(struct platform_device *pdev)
 301{
 302        struct Scsi_Host *host = platform_get_drvdata(pdev);
 303        struct ip22_hostdata *hdata = (struct ip22_hostdata *) host->hostdata;
 304        struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
 305
 306        scsi_remove_host(host);
 307        free_irq(pd->irq, host);
 308        dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma);
 309        scsi_host_put(host);
 310        return 0;
 311}
 312
 313static struct platform_driver sgiwd93_driver = {
 314        .probe  = sgiwd93_probe,
 315        .remove = __devexit_p(sgiwd93_remove),
 316        .driver = {
 317                .name   = "sgiwd93",
 318                .owner  = THIS_MODULE,
 319        }
 320};
 321
 322static int __init sgiwd93_module_init(void)
 323{
 324        return platform_driver_register(&sgiwd93_driver);
 325}
 326
 327static void __exit sgiwd93_module_exit(void)
 328{
 329        return platform_driver_unregister(&sgiwd93_driver);
 330}
 331
 332module_init(sgiwd93_module_init);
 333module_exit(sgiwd93_module_exit);
 334
 335MODULE_DESCRIPTION("SGI WD33C93 driver");
 336MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
 337MODULE_LICENSE("GPL");
 338MODULE_ALIAS("platform:sgiwd93");
 339
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