drivers/scsi/sgiwd93.c

   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
  34 struct 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
  43 struct 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
  53 static 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
  65 static inline
  66 void 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_sync_single_for_device(hd->dev, hd->dma,
  99                        (unsigned long)(hcp + 1) - (unsigned long)hd->cpu,
 100                        DMA_TO_DEVICE);
 101 }
 102
 103 static 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
 136 static 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
 166 void 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 }
 174 EXPORT_SYMBOL_GPL(sgiwd93_reset);
 175
 176 static 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
 195 /*
 196  * Kludge alert - the SCSI code calls the abort and reset method with int
 197  * arguments not with pointers.  So this is going to blow up beautyfully
 198  * on 64-bit systems with memory outside the compat address spaces.
 199  */
 200 static struct scsi_host_template sgiwd93_template = {
 201         .module                 = THIS_MODULE,
 202         .proc_name              = "SGIWD93",
 203         .name                   = "SGI WD93",
 204         .queuecommand           = wd33c93_queuecommand,
 205         .eh_abort_handler       = wd33c93_abort,
 206         .eh_host_reset_handler  = wd33c93_host_reset,
 207         .can_queue              = 16,
 208         .this_id                = 7,
 209         .sg_tablesize           = SG_ALL,
 210         .cmd_per_lun            = 8,
 211         .dma_boundary           = PAGE_SIZE - 1,
 212 };
 213
 214 static int sgiwd93_probe(struct platform_device *pdev)
 215 {
 216         struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
 217         unsigned char *wdregs = pd->wdregs;
 218         struct hpc3_scsiregs *hregs = pd->hregs;
 219         struct ip22_hostdata *hdata;
 220         struct Scsi_Host *host;
 221         wd33c93_regs regs;
 222         unsigned int unit = pd->unit;
 223         unsigned int irq = pd->irq;
 224         int err;
 225
 226         host = scsi_host_alloc(&sgiwd93_template, sizeof(struct ip22_hostdata));
 227         if (!host) {
 228                 err = -ENOMEM;
 229                 goto out;
 230         }
 231
 232         host->base = (unsigned long) hregs;
 233         host->irq = irq;
 234
 235         hdata = host_to_hostdata(host);
 236         hdata->dev = &pdev->dev;
 237         hdata->cpu = dma_alloc_noncoherent(&pdev->dev, HPC_DMA_SIZE,
 238                                 &hdata->dma, DMA_TO_DEVICE, GFP_KERNEL);
 239         if (!hdata->cpu) {
 240                 printk(KERN_WARNING "sgiwd93: Could not allocate memory for "
 241                        "host %d buffer.\n", unit);
 242                 err = -ENOMEM;
 243                 goto out_put;
 244         }
 245
 246         init_hpc_chain(hdata);
 247
 248         regs.SASR = wdregs + 3;
 249         regs.SCMD = wdregs + 7;
 250
 251         hdata->wh.no_sync = 0;
 252         hdata->wh.fast = 1;
 253         hdata->wh.dma_mode = CTRL_BURST;
 254
 255         wd33c93_init(host, regs, dma_setup, dma_stop, WD33C93_FS_MHZ(20));
 256
 257         err = request_irq(irq, sgiwd93_intr, 0, "SGI WD93", host);
 258         if (err) {
 259                 printk(KERN_WARNING "sgiwd93: Could not register irq %d "
 260                        "for host %d.\n", irq, unit);
 261                 goto out_free;
 262         }
 263
 264         platform_set_drvdata(pdev, host);
 265
 266         err = scsi_add_host(host, NULL);
 267         if (err)
 268                 goto out_irq;
 269
 270         scsi_scan_host(host);
 271
 272         return 0;
 273
 274 out_irq:
 275         free_irq(irq, host);
 276 out_free:
 277         dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma,
 278                         DMA_TO_DEVICE);
 279 out_put:
 280         scsi_host_put(host);
 281 out:
 282
 283         return err;
 284 }
 285
 286 static int sgiwd93_remove(struct platform_device *pdev)
 287 {
 288         struct Scsi_Host *host = platform_get_drvdata(pdev);
 289         struct ip22_hostdata *hdata = (struct ip22_hostdata *) host->hostdata;
 290         struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
 291
 292         scsi_remove_host(host);
 293         free_irq(pd->irq, host);
 294         dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma,
 295                         DMA_TO_DEVICE);
 296         scsi_host_put(host);
 297         return 0;
 298 }
 299
 300 static struct platform_driver sgiwd93_driver = {
 301         .probe  = sgiwd93_probe,
 302         .remove = sgiwd93_remove,
 303         .driver = {
 304                 .name   = "sgiwd93",
 305         }
 306 };
 307
 308 static int __init sgiwd93_module_init(void)
 309 {
 310         return platform_driver_register(&sgiwd93_driver);
 311 }
 312
 313 static void __exit sgiwd93_module_exit(void)
 314 {
 315         return platform_driver_unregister(&sgiwd93_driver);
 316 }
 317
 318 module_init(sgiwd93_module_init);
 319 module_exit(sgiwd93_module_exit);
 320
 321 MODULE_DESCRIPTION("SGI WD33C93 driver");
 322 MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
 323 MODULE_LICENSE("GPL");
 324 MODULE_ALIAS("platform:sgiwd93");