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