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/scsi.h>
  32 #include <scsi/scsi_cmnd.h>
  33 #include <scsi/scsi_device.h>
  34 #include <scsi/scsi_eh.h>
  35 #include <scsi/scsi_tcq.h>
  36 #include "wd33c93.h"
  37
  38 struct ip22_hostdata {
  39         struct WD33C93_hostdata wh;
  40         dma_addr_t dma;
  41         void *cpu;
  42         struct device *dev;
  43 };
  44
  45 #define host_to_hostdata(host) ((struct ip22_hostdata *)((host)->hostdata))
  46
  47 struct hpc_chunk {
  48         struct hpc_dma_desc desc;
  49         u32 _padding;   /* align to quadword boundary */
  50 };
  51
  52 /* space for hpc dma descriptors */
  53 #define HPC_DMA_SIZE   PAGE_SIZE
  54
  55 #define DMA_DIR(d)   ((d == DATA_OUT_DIR) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
  56
  57 static irqreturn_t sgiwd93_intr(int irq, void *dev_id)
  58 {
  59         struct Scsi_Host * host = dev_id;
  60         unsigned long flags;
  61
  62         spin_lock_irqsave(host->host_lock, flags);
  63         wd33c93_intr(host);
  64         spin_unlock_irqrestore(host->host_lock, flags);
  65
  66         return IRQ_HANDLED;
  67 }
  68
  69 static inline
  70 void fill_hpc_entries(struct ip22_hostdata *hd, struct scsi_cmnd *cmd, int din)
  71 {
  72         struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(cmd);
  73         unsigned long len = scsi_pointer->this_residual;
  74         void *addr = scsi_pointer->ptr;
  75         dma_addr_t physaddr;
  76         unsigned long count;
  77         struct hpc_chunk *hcp;
  78
  79         physaddr = dma_map_single(hd->dev, addr, len, DMA_DIR(din));
  80         scsi_pointer->dma_handle = physaddr;
  81         hcp = hd->cpu;
  82
  83         while (len) {
  84                 /*
  85                  * even cntinfo could be up to 16383, without
  86                  * magic only 8192 works correctly
  87                  */
  88                 count = len > 8192 ? 8192 : len;
  89                 hcp->desc.pbuf = physaddr;
  90                 hcp->desc.cntinfo = count;
  91                 hcp++;
  92                 len -= count;
  93                 physaddr += count;
  94         }
  95
  96         /*
  97          * To make sure, if we trip an HPC bug, that we transfer every single
  98          * byte, we tag on an extra zero length dma descriptor at the end of
  99          * the chain.
 100          */
 101         hcp->desc.pbuf = 0;
 102         hcp->desc.cntinfo = HPCDMA_EOX;
 103         dma_sync_single_for_device(hd->dev, hd->dma,
 104                        (unsigned long)(hcp + 1) - (unsigned long)hd->cpu,
 105                        DMA_TO_DEVICE);
 106 }
 107
 108 static int dma_setup(struct scsi_cmnd *cmd, int datainp)
 109 {
 110         struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(cmd);
 111         struct ip22_hostdata *hdata = host_to_hostdata(cmd->device->host);
 112         struct hpc3_scsiregs *hregs =
 113                 (struct hpc3_scsiregs *) cmd->device->host->base;
 114
 115         pr_debug("dma_setup: datainp<%d> hcp<%p> ", datainp, hdata->cpu);
 116
 117         hdata->wh.dma_dir = datainp;
 118
 119         /*
 120          * wd33c93 shouldn't pass us bogus dma_setups, but it does:-(  The
 121          * other wd33c93 drivers deal with it the same way (which isn't that
 122          * obvious).  IMHO a better fix would be, not to do these dma setups
 123          * in the first place.
 124          */
 125         if (scsi_pointer->ptr == NULL || scsi_pointer->this_residual == 0)
 126                 return 1;
 127
 128         fill_hpc_entries(hdata, cmd, datainp);
 129
 130         pr_debug(" HPCGO\n");
 131
 132         /* Start up the HPC. */
 133         hregs->ndptr = hdata->dma;
 134         if (datainp)
 135                 hregs->ctrl = HPC3_SCTRL_ACTIVE;
 136         else
 137                 hregs->ctrl = HPC3_SCTRL_ACTIVE | HPC3_SCTRL_DIR;
 138
 139         return 0;
 140 }
 141
 142 static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
 143                      int status)
 144 {
 145         struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(SCpnt);
 146         struct ip22_hostdata *hdata = host_to_hostdata(instance);
 147         struct hpc3_scsiregs *hregs;
 148
 149         if (!SCpnt)
 150                 return;
 151
 152         if (scsi_pointer->ptr == NULL || scsi_pointer->this_residual == 0)
 153                 return;
 154
 155         hregs = (struct hpc3_scsiregs *) SCpnt->device->host->base;
 156
 157         pr_debug("dma_stop: status<%d> ", status);
 158
 159         /* First stop the HPC and flush it's FIFO. */
 160         if (hdata->wh.dma_dir) {
 161                 hregs->ctrl |= HPC3_SCTRL_FLUSH;
 162                 while (hregs->ctrl & HPC3_SCTRL_ACTIVE)
 163                         barrier();
 164         }
 165         hregs->ctrl = 0;
 166         dma_unmap_single(hdata->dev, scsi_pointer->dma_handle,
 167                          scsi_pointer->this_residual,
 168                          DMA_DIR(hdata->wh.dma_dir));
 169
 170         pr_debug("\n");
 171 }
 172
 173 void sgiwd93_reset(unsigned long base)
 174 {
 175         struct hpc3_scsiregs *hregs = (struct hpc3_scsiregs *) base;
 176
 177         hregs->ctrl = HPC3_SCTRL_CRESET;
 178         udelay(50);
 179         hregs->ctrl = 0;
 180 }
 181 EXPORT_SYMBOL_GPL(sgiwd93_reset);
 182
 183 static inline void init_hpc_chain(struct ip22_hostdata *hdata)
 184 {
 185         struct hpc_chunk *hcp = (struct hpc_chunk *)hdata->cpu;
 186         dma_addr_t dma = hdata->dma;
 187         unsigned long start, end;
 188
 189         start = (unsigned long) hcp;
 190         end = start + HPC_DMA_SIZE;
 191         while (start < end) {
 192                 hcp->desc.pnext = (u32) (dma + sizeof(struct hpc_chunk));
 193                 hcp->desc.cntinfo = HPCDMA_EOX;
 194                 hcp++;
 195                 dma += sizeof(struct hpc_chunk);
 196                 start += sizeof(struct hpc_chunk);
 197         }
 198         hcp--;
 199         hcp->desc.pnext = hdata->dma;
 200 }
 201
 202 /*
 203  * Kludge alert - the SCSI code calls the abort and reset method with int
 204  * arguments not with pointers.  So this is going to blow up beautyfully
 205  * on 64-bit systems with memory outside the compat address spaces.
 206  */
 207 static const struct scsi_host_template sgiwd93_template = {
 208         .module                 = THIS_MODULE,
 209         .proc_name              = "SGIWD93",
 210         .name                   = "SGI WD93",
 211         .queuecommand           = wd33c93_queuecommand,
 212         .eh_abort_handler       = wd33c93_abort,
 213         .eh_host_reset_handler  = wd33c93_host_reset,
 214         .can_queue              = 16,
 215         .this_id                = 7,
 216         .sg_tablesize           = SG_ALL,
 217         .cmd_per_lun            = 8,
 218         .dma_boundary           = PAGE_SIZE - 1,
 219         .cmd_size               = sizeof(struct scsi_pointer),
 220 };
 221
 222 static int sgiwd93_probe(struct platform_device *pdev)
 223 {
 224         struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
 225         unsigned char *wdregs = pd->wdregs;
 226         struct hpc3_scsiregs *hregs = pd->hregs;
 227         struct ip22_hostdata *hdata;
 228         struct Scsi_Host *host;
 229         wd33c93_regs regs;
 230         unsigned int unit = pd->unit;
 231         unsigned int irq = pd->irq;
 232         int err;
 233
 234         host = scsi_host_alloc(&sgiwd93_template, sizeof(struct ip22_hostdata));
 235         if (!host) {
 236                 err = -ENOMEM;
 237                 goto out;
 238         }
 239
 240         host->base = (unsigned long) hregs;
 241         host->irq = irq;
 242
 243         hdata = host_to_hostdata(host);
 244         hdata->dev = &pdev->dev;
 245         hdata->cpu = dma_alloc_noncoherent(&pdev->dev, HPC_DMA_SIZE,
 246                                 &hdata->dma, DMA_TO_DEVICE, GFP_KERNEL);
 247         if (!hdata->cpu) {
 248                 printk(KERN_WARNING "sgiwd93: Could not allocate memory for "
 249                        "host %d buffer.\n", unit);
 250                 err = -ENOMEM;
 251                 goto out_put;
 252         }
 253
 254         init_hpc_chain(hdata);
 255
 256         regs.SASR = wdregs + 3;
 257         regs.SCMD = wdregs + 7;
 258
 259         hdata->wh.no_sync = 0;
 260         hdata->wh.fast = 1;
 261         hdata->wh.dma_mode = CTRL_BURST;
 262
 263         wd33c93_init(host, regs, dma_setup, dma_stop, WD33C93_FS_MHZ(20));
 264
 265         err = request_irq(irq, sgiwd93_intr, 0, "SGI WD93", host);
 266         if (err) {
 267                 printk(KERN_WARNING "sgiwd93: Could not register irq %d "
 268                        "for host %d.\n", irq, unit);
 269                 goto out_free;
 270         }
 271
 272         platform_set_drvdata(pdev, host);
 273
 274         err = scsi_add_host(host, NULL);
 275         if (err)
 276                 goto out_irq;
 277
 278         scsi_scan_host(host);
 279
 280         return 0;
 281
 282 out_irq:
 283         free_irq(irq, host);
 284 out_free:
 285         dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma,
 286                         DMA_TO_DEVICE);
 287 out_put:
 288         scsi_host_put(host);
 289 out:
 290
 291         return err;
 292 }
 293
 294 static void sgiwd93_remove(struct platform_device *pdev)
 295 {
 296         struct Scsi_Host *host = platform_get_drvdata(pdev);
 297         struct ip22_hostdata *hdata = (struct ip22_hostdata *) host->hostdata;
 298         struct sgiwd93_platform_data *pd = pdev->dev.platform_data;
 299
 300         scsi_remove_host(host);
 301         free_irq(pd->irq, host);
 302         dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma,
 303                         DMA_TO_DEVICE);
 304         scsi_host_put(host);
 305 }
 306
 307 static struct platform_driver sgiwd93_driver = {
 308         .probe  = sgiwd93_probe,
 309         .remove_new = sgiwd93_remove,
 310         .driver = {
 311                 .name   = "sgiwd93",
 312         }
 313 };
 314
 315 static int __init sgiwd93_module_init(void)
 316 {
 317         return platform_driver_register(&sgiwd93_driver);
 318 }
 319
 320 static void __exit sgiwd93_module_exit(void)
 321 {
 322         return platform_driver_unregister(&sgiwd93_driver);
 323 }
 324
 325 module_init(sgiwd93_module_init);
 326 module_exit(sgiwd93_module_exit);
 327
 328 MODULE_DESCRIPTION("SGI WD33C93 driver");
 329 MODULE_AUTHOR("Ralf Baechle <ralf@linux-mips.org>");
 330 MODULE_LICENSE("GPL");
 331 MODULE_ALIAS("platform:sgiwd93");