drivers/scsi/a3000.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <linux/types.h>
   3 #include <linux/mm.h>
   4 #include <linux/ioport.h>
   5 #include <linux/init.h>
   6 #include <linux/slab.h>
   7 #include <linux/spinlock.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/platform_device.h>
  10 #include <linux/module.h>
  11
  12 #include <asm/page.h>
  13 #include <asm/pgtable.h>
  14 #include <asm/amigaints.h>
  15 #include <asm/amigahw.h>
  16
  17 #include "scsi.h"
  18 #include "wd33c93.h"
  19 #include "a3000.h"
  20
  21
  22 struct a3000_hostdata {
  23         struct WD33C93_hostdata wh;
  24         struct a3000_scsiregs *regs;
  25 };
  26
  27 static irqreturn_t a3000_intr(int irq, void *data)
  28 {
  29         struct Scsi_Host *instance = data;
  30         struct a3000_hostdata *hdata = shost_priv(instance);
  31         unsigned int status = hdata->regs->ISTR;
  32         unsigned long flags;
  33
  34         if (!(status & ISTR_INT_P))
  35                 return IRQ_NONE;
  36         if (status & ISTR_INTS) {
  37                 spin_lock_irqsave(instance->host_lock, flags);
  38                 wd33c93_intr(instance);
  39                 spin_unlock_irqrestore(instance->host_lock, flags);
  40                 return IRQ_HANDLED;
  41         }
  42         pr_warning("Non-serviced A3000 SCSI-interrupt? ISTR = %02x\n", status);
  43         return IRQ_NONE;
  44 }
  45
  46 static int dma_setup(struct scsi_cmnd *cmd, int dir_in)
  47 {
  48         struct Scsi_Host *instance = cmd->device->host;
  49         struct a3000_hostdata *hdata = shost_priv(instance);
  50         struct WD33C93_hostdata *wh = &hdata->wh;
  51         struct a3000_scsiregs *regs = hdata->regs;
  52         unsigned short cntr = CNTR_PDMD | CNTR_INTEN;
  53         unsigned long addr = virt_to_bus(cmd->SCp.ptr);
  54
  55         /*
  56          * if the physical address has the wrong alignment, or if
  57          * physical address is bad, or if it is a write and at the
  58          * end of a physical memory chunk, then allocate a bounce
  59          * buffer
  60          */
  61         if (addr & A3000_XFER_MASK) {
  62                 wh->dma_bounce_len = (cmd->SCp.this_residual + 511) & ~0x1ff;
  63                 wh->dma_bounce_buffer = kmalloc(wh->dma_bounce_len,
  64                                                 GFP_KERNEL);
  65
  66                 /* can't allocate memory; use PIO */
  67                 if (!wh->dma_bounce_buffer) {
  68                         wh->dma_bounce_len = 0;
  69                         return 1;
  70                 }
  71
  72                 if (!dir_in) {
  73                         /* copy to bounce buffer for a write */
  74                         memcpy(wh->dma_bounce_buffer, cmd->SCp.ptr,
  75                                cmd->SCp.this_residual);
  76                 }
  77
  78                 addr = virt_to_bus(wh->dma_bounce_buffer);
  79         }
  80
  81         /* setup dma direction */
  82         if (!dir_in)
  83                 cntr |= CNTR_DDIR;
  84
  85         /* remember direction */
  86         wh->dma_dir = dir_in;
  87
  88         regs->CNTR = cntr;
  89
  90         /* setup DMA *physical* address */
  91         regs->ACR = addr;
  92
  93         if (dir_in) {
  94                 /* invalidate any cache */
  95                 cache_clear(addr, cmd->SCp.this_residual);
  96         } else {
  97                 /* push any dirty cache */
  98                 cache_push(addr, cmd->SCp.this_residual);
  99         }
 100
 101         /* start DMA */
 102         mb();                   /* make sure setup is completed */
 103         regs->ST_DMA = 1;
 104         mb();                   /* make sure DMA has started before next IO */
 105
 106         /* return success */
 107         return 0;
 108 }
 109
 110 static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
 111                      int status)
 112 {
 113         struct a3000_hostdata *hdata = shost_priv(instance);
 114         struct WD33C93_hostdata *wh = &hdata->wh;
 115         struct a3000_scsiregs *regs = hdata->regs;
 116
 117         /* disable SCSI interrupts */
 118         unsigned short cntr = CNTR_PDMD;
 119
 120         if (!wh->dma_dir)
 121                 cntr |= CNTR_DDIR;
 122
 123         regs->CNTR = cntr;
 124         mb();                   /* make sure CNTR is updated before next IO */
 125
 126         /* flush if we were reading */
 127         if (wh->dma_dir) {
 128                 regs->FLUSH = 1;
 129                 mb();           /* don't allow prefetch */
 130                 while (!(regs->ISTR & ISTR_FE_FLG))
 131                         barrier();
 132                 mb();           /* no IO until FLUSH is done */
 133         }
 134
 135         /* clear a possible interrupt */
 136         /* I think that this CINT is only necessary if you are
 137          * using the terminal count features.   HM 7 Mar 1994
 138          */
 139         regs->CINT = 1;
 140
 141         /* stop DMA */
 142         regs->SP_DMA = 1;
 143         mb();                   /* make sure DMA is stopped before next IO */
 144
 145         /* restore the CONTROL bits (minus the direction flag) */
 146         regs->CNTR = CNTR_PDMD | CNTR_INTEN;
 147         mb();                   /* make sure CNTR is updated before next IO */
 148
 149         /* copy from a bounce buffer, if necessary */
 150         if (status && wh->dma_bounce_buffer) {
 151                 if (SCpnt) {
 152                         if (wh->dma_dir && SCpnt)
 153                                 memcpy(SCpnt->SCp.ptr, wh->dma_bounce_buffer,
 154                                        SCpnt->SCp.this_residual);
 155                         kfree(wh->dma_bounce_buffer);
 156                         wh->dma_bounce_buffer = NULL;
 157                         wh->dma_bounce_len = 0;
 158                 } else {
 159                         kfree(wh->dma_bounce_buffer);
 160                         wh->dma_bounce_buffer = NULL;
 161                         wh->dma_bounce_len = 0;
 162                 }
 163         }
 164 }
 165
 166 static struct scsi_host_template amiga_a3000_scsi_template = {
 167         .module                 = THIS_MODULE,
 168         .name                   = "Amiga 3000 built-in SCSI",
 169         .show_info              = wd33c93_show_info,
 170         .write_info             = wd33c93_write_info,
 171         .proc_name              = "A3000",
 172         .queuecommand           = wd33c93_queuecommand,
 173         .eh_abort_handler       = wd33c93_abort,
 174         .eh_host_reset_handler  = wd33c93_host_reset,
 175         .can_queue              = CAN_QUEUE,
 176         .this_id                = 7,
 177         .sg_tablesize           = SG_ALL,
 178         .cmd_per_lun            = CMD_PER_LUN,
 179 };
 180
 181 static int __init amiga_a3000_scsi_probe(struct platform_device *pdev)
 182 {
 183         struct resource *res;
 184         struct Scsi_Host *instance;
 185         int error;
 186         struct a3000_scsiregs *regs;
 187         wd33c93_regs wdregs;
 188         struct a3000_hostdata *hdata;
 189
 190         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 191         if (!res)
 192                 return -ENODEV;
 193
 194         if (!request_mem_region(res->start, resource_size(res), "wd33c93"))
 195                 return -EBUSY;
 196
 197         instance = scsi_host_alloc(&amiga_a3000_scsi_template,
 198                                    sizeof(struct a3000_hostdata));
 199         if (!instance) {
 200                 error = -ENOMEM;
 201                 goto fail_alloc;
 202         }
 203
 204         instance->irq = IRQ_AMIGA_PORTS;
 205
 206         regs = ZTWO_VADDR(res->start);
 207         regs->DAWR = DAWR_A3000;
 208
 209         wdregs.SASR = &regs->SASR;
 210         wdregs.SCMD = &regs->SCMD;
 211
 212         hdata = shost_priv(instance);
 213         hdata->wh.no_sync = 0xff;
 214         hdata->wh.fast = 0;
 215         hdata->wh.dma_mode = CTRL_DMA;
 216         hdata->regs = regs;
 217
 218         wd33c93_init(instance, wdregs, dma_setup, dma_stop, WD33C93_FS_12_15);
 219         error = request_irq(IRQ_AMIGA_PORTS, a3000_intr, IRQF_SHARED,
 220                             "A3000 SCSI", instance);
 221         if (error)
 222                 goto fail_irq;
 223
 224         regs->CNTR = CNTR_PDMD | CNTR_INTEN;
 225
 226         error = scsi_add_host(instance, NULL);
 227         if (error)
 228                 goto fail_host;
 229
 230         platform_set_drvdata(pdev, instance);
 231
 232         scsi_scan_host(instance);
 233         return 0;
 234
 235 fail_host:
 236         free_irq(IRQ_AMIGA_PORTS, instance);
 237 fail_irq:
 238         scsi_host_put(instance);
 239 fail_alloc:
 240         release_mem_region(res->start, resource_size(res));
 241         return error;
 242 }
 243
 244 static int __exit amiga_a3000_scsi_remove(struct platform_device *pdev)
 245 {
 246         struct Scsi_Host *instance = platform_get_drvdata(pdev);
 247         struct a3000_hostdata *hdata = shost_priv(instance);
 248         struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 249
 250         hdata->regs->CNTR = 0;
 251         scsi_remove_host(instance);
 252         free_irq(IRQ_AMIGA_PORTS, instance);
 253         scsi_host_put(instance);
 254         release_mem_region(res->start, resource_size(res));
 255         return 0;
 256 }
 257
 258 static struct platform_driver amiga_a3000_scsi_driver = {
 259         .remove = __exit_p(amiga_a3000_scsi_remove),
 260         .driver   = {
 261                 .name   = "amiga-a3000-scsi",
 262         },
 263 };
 264
 265 module_platform_driver_probe(amiga_a3000_scsi_driver, amiga_a3000_scsi_probe);
 266
 267 MODULE_DESCRIPTION("Amiga 3000 built-in SCSI");
 268 MODULE_LICENSE("GPL");
 269 MODULE_ALIAS("platform:amiga-a3000-scsi");