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