drivers/scsi/sun3x_esp.c

   1 /* sun3x_esp.c: ESP front-end for Sun3x systems.
   2  *
   3  * Copyright (C) 2007,2008 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/gfp.h>
   8 #include <linux/types.h>
   9 #include <linux/delay.h>
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/dma-mapping.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/io.h>
  16
  17 #include <asm/sun3x.h>
  18 #include <asm/dma.h>
  19 #include <asm/dvma.h>
  20
  21 /* DMA controller reg offsets */
  22 #define DMA_CSR         0x00UL  /* rw  DMA control/status register    0x00   */
  23 #define DMA_ADDR        0x04UL  /* rw  DMA transfer address register  0x04   */
  24 #define DMA_COUNT       0x08UL  /* rw  DMA transfer count register    0x08   */
  25 #define DMA_TEST        0x0cUL  /* rw  DMA test/debug register        0x0c   */
  26
  27 #include <scsi/scsi_host.h>
  28
  29 #include "esp_scsi.h"
  30
  31 #define DRV_MODULE_NAME         "sun3x_esp"
  32 #define PFX DRV_MODULE_NAME     ": "
  33 #define DRV_VERSION             "1.000"
  34 #define DRV_MODULE_RELDATE      "Nov 1, 2007"
  35
  36 /*
  37  * m68k always assumes readl/writel operate on little endian
  38  * mmio space; this is wrong at least for Sun3x, so we
  39  * need to workaround this until a proper way is found
  40  */
  41 #if 0
  42 #define dma_read32(REG) \
  43         readl(esp->dma_regs + (REG))
  44 #define dma_write32(VAL, REG) \
  45         writel((VAL), esp->dma_regs + (REG))
  46 #else
  47 #define dma_read32(REG) \
  48         *(volatile u32 *)(esp->dma_regs + (REG))
  49 #define dma_write32(VAL, REG) \
  50         do { *(volatile u32 *)(esp->dma_regs + (REG)) = (VAL); } while (0)
  51 #endif
  52
  53 static void sun3x_esp_write8(struct esp *esp, u8 val, unsigned long reg)
  54 {
  55         writeb(val, esp->regs + (reg * 4UL));
  56 }
  57
  58 static u8 sun3x_esp_read8(struct esp *esp, unsigned long reg)
  59 {
  60         return readb(esp->regs + (reg * 4UL));
  61 }
  62
  63 static dma_addr_t sun3x_esp_map_single(struct esp *esp, void *buf,
  64                                       size_t sz, int dir)
  65 {
  66         return dma_map_single(esp->dev, buf, sz, dir);
  67 }
  68
  69 static int sun3x_esp_map_sg(struct esp *esp, struct scatterlist *sg,
  70                                   int num_sg, int dir)
  71 {
  72         return dma_map_sg(esp->dev, sg, num_sg, dir);
  73 }
  74
  75 static void sun3x_esp_unmap_single(struct esp *esp, dma_addr_t addr,
  76                                   size_t sz, int dir)
  77 {
  78         dma_unmap_single(esp->dev, addr, sz, dir);
  79 }
  80
  81 static void sun3x_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
  82                               int num_sg, int dir)
  83 {
  84         dma_unmap_sg(esp->dev, sg, num_sg, dir);
  85 }
  86
  87 static int sun3x_esp_irq_pending(struct esp *esp)
  88 {
  89         if (dma_read32(DMA_CSR) & (DMA_HNDL_INTR | DMA_HNDL_ERROR))
  90                 return 1;
  91         return 0;
  92 }
  93
  94 static void sun3x_esp_reset_dma(struct esp *esp)
  95 {
  96         u32 val;
  97
  98         val = dma_read32(DMA_CSR);
  99         dma_write32(val | DMA_RST_SCSI, DMA_CSR);
 100         dma_write32(val & ~DMA_RST_SCSI, DMA_CSR);
 101
 102         /* Enable interrupts.  */
 103         val = dma_read32(DMA_CSR);
 104         dma_write32(val | DMA_INT_ENAB, DMA_CSR);
 105 }
 106
 107 static void sun3x_esp_dma_drain(struct esp *esp)
 108 {
 109         u32 csr;
 110         int lim;
 111
 112         csr = dma_read32(DMA_CSR);
 113         if (!(csr & DMA_FIFO_ISDRAIN))
 114                 return;
 115
 116         dma_write32(csr | DMA_FIFO_STDRAIN, DMA_CSR);
 117
 118         lim = 1000;
 119         while (dma_read32(DMA_CSR) & DMA_FIFO_ISDRAIN) {
 120                 if (--lim == 0) {
 121                         printk(KERN_ALERT PFX "esp%d: DMA will not drain!\n",
 122                                esp->host->unique_id);
 123                         break;
 124                 }
 125                 udelay(1);
 126         }
 127 }
 128
 129 static void sun3x_esp_dma_invalidate(struct esp *esp)
 130 {
 131         u32 val;
 132         int lim;
 133
 134         lim = 1000;
 135         while ((val = dma_read32(DMA_CSR)) & DMA_PEND_READ) {
 136                 if (--lim == 0) {
 137                         printk(KERN_ALERT PFX "esp%d: DMA will not "
 138                                "invalidate!\n", esp->host->unique_id);
 139                         break;
 140                 }
 141                 udelay(1);
 142         }
 143
 144         val &= ~(DMA_ENABLE | DMA_ST_WRITE | DMA_BCNT_ENAB);
 145         val |= DMA_FIFO_INV;
 146         dma_write32(val, DMA_CSR);
 147         val &= ~DMA_FIFO_INV;
 148         dma_write32(val, DMA_CSR);
 149 }
 150
 151 static void sun3x_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count,
 152                                   u32 dma_count, int write, u8 cmd)
 153 {
 154         u32 csr;
 155
 156         BUG_ON(!(cmd & ESP_CMD_DMA));
 157
 158         sun3x_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
 159         sun3x_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
 160         csr = dma_read32(DMA_CSR);
 161         csr |= DMA_ENABLE;
 162         if (write)
 163                 csr |= DMA_ST_WRITE;
 164         else
 165                 csr &= ~DMA_ST_WRITE;
 166         dma_write32(csr, DMA_CSR);
 167         dma_write32(addr, DMA_ADDR);
 168
 169         scsi_esp_cmd(esp, cmd);
 170 }
 171
 172 static int sun3x_esp_dma_error(struct esp *esp)
 173 {
 174         u32 csr = dma_read32(DMA_CSR);
 175
 176         if (csr & DMA_HNDL_ERROR)
 177                 return 1;
 178
 179         return 0;
 180 }
 181
 182 static const struct esp_driver_ops sun3x_esp_ops = {
 183         .esp_write8     =       sun3x_esp_write8,
 184         .esp_read8      =       sun3x_esp_read8,
 185         .map_single     =       sun3x_esp_map_single,
 186         .map_sg         =       sun3x_esp_map_sg,
 187         .unmap_single   =       sun3x_esp_unmap_single,
 188         .unmap_sg       =       sun3x_esp_unmap_sg,
 189         .irq_pending    =       sun3x_esp_irq_pending,
 190         .reset_dma      =       sun3x_esp_reset_dma,
 191         .dma_drain      =       sun3x_esp_dma_drain,
 192         .dma_invalidate =       sun3x_esp_dma_invalidate,
 193         .send_dma_cmd   =       sun3x_esp_send_dma_cmd,
 194         .dma_error      =       sun3x_esp_dma_error,
 195 };
 196
 197 static int esp_sun3x_probe(struct platform_device *dev)
 198 {
 199         struct scsi_host_template *tpnt = &scsi_esp_template;
 200         struct Scsi_Host *host;
 201         struct esp *esp;
 202         struct resource *res;
 203         int err = -ENOMEM;
 204
 205         host = scsi_host_alloc(tpnt, sizeof(struct esp));
 206         if (!host)
 207                 goto fail;
 208
 209         host->max_id = 8;
 210         esp = shost_priv(host);
 211
 212         esp->host = host;
 213         esp->dev = dev;
 214         esp->ops = &sun3x_esp_ops;
 215
 216         res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 217         if (!res || !res->start)
 218                 goto fail_unlink;
 219
 220         esp->regs = ioremap_nocache(res->start, 0x20);
 221         if (!esp->regs)
 222                 goto fail_unmap_regs;
 223
 224         res = platform_get_resource(dev, IORESOURCE_MEM, 1);
 225         if (!res || !res->start)
 226                 goto fail_unmap_regs;
 227
 228         esp->dma_regs = ioremap_nocache(res->start, 0x10);
 229
 230         esp->command_block = dma_alloc_coherent(esp->dev, 16,
 231                                                 &esp->command_block_dma,
 232                                                 GFP_KERNEL);
 233         if (!esp->command_block)
 234                 goto fail_unmap_regs_dma;
 235
 236         host->irq = platform_get_irq(dev, 0);
 237         err = request_irq(host->irq, scsi_esp_intr, IRQF_SHARED,
 238                           "SUN3X ESP", esp);
 239         if (err < 0)
 240                 goto fail_unmap_command_block;
 241
 242         esp->scsi_id = 7;
 243         esp->host->this_id = esp->scsi_id;
 244         esp->scsi_id_mask = (1 << esp->scsi_id);
 245         esp->cfreq = 20000000;
 246
 247         dev_set_drvdata(&dev->dev, esp);
 248
 249         err = scsi_esp_register(esp, &dev->dev);
 250         if (err)
 251                 goto fail_free_irq;
 252
 253         return 0;
 254
 255 fail_free_irq:
 256         free_irq(host->irq, esp);
 257 fail_unmap_command_block:
 258         dma_free_coherent(esp->dev, 16,
 259                           esp->command_block,
 260                           esp->command_block_dma);
 261 fail_unmap_regs_dma:
 262         iounmap(esp->dma_regs);
 263 fail_unmap_regs:
 264         iounmap(esp->regs);
 265 fail_unlink:
 266         scsi_host_put(host);
 267 fail:
 268         return err;
 269 }
 270
 271 static int esp_sun3x_remove(struct platform_device *dev)
 272 {
 273         struct esp *esp = dev_get_drvdata(&dev->dev);
 274         unsigned int irq = esp->host->irq;
 275         u32 val;
 276
 277         scsi_esp_unregister(esp);
 278
 279         /* Disable interrupts.  */
 280         val = dma_read32(DMA_CSR);
 281         dma_write32(val & ~DMA_INT_ENAB, DMA_CSR);
 282
 283         free_irq(irq, esp);
 284         dma_free_coherent(esp->dev, 16,
 285                           esp->command_block,
 286                           esp->command_block_dma);
 287
 288         scsi_host_put(esp->host);
 289
 290         return 0;
 291 }
 292
 293 static struct platform_driver esp_sun3x_driver = {
 294         .probe          = esp_sun3x_probe,
 295         .remove         = esp_sun3x_remove,
 296         .driver = {
 297                 .name   = "sun3x_esp",
 298         },
 299 };
 300
 301 static int __init sun3x_esp_init(void)
 302 {
 303         return platform_driver_register(&esp_sun3x_driver);
 304 }
 305
 306 static void __exit sun3x_esp_exit(void)
 307 {
 308         platform_driver_unregister(&esp_sun3x_driver);
 309 }
 310
 311 MODULE_DESCRIPTION("Sun3x ESP SCSI driver");
 312 MODULE_AUTHOR("Thomas Bogendoerfer (tsbogend@alpha.franken.de)");
 313 MODULE_LICENSE("GPL");
 314 MODULE_VERSION(DRV_VERSION);
 315
 316 module_init(sun3x_esp_init);
 317 module_exit(sun3x_esp_exit);
 318 MODULE_ALIAS("platform:sun3x_esp");