release/src-rt-6.x.4708/linux/linux-2.6.36/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
  16 #include <asm/sun3x.h>
  17 #include <asm/io.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 #define dma_read32(REG) \
  37         *(volatile u32 *)(esp->dma_regs + (REG))
  38 #define dma_write32(VAL, REG) \
  39         do { *(volatile u32 *)(esp->dma_regs + (REG)) = (VAL); } while (0)
  40
  41 static void sun3x_esp_write8(struct esp *esp, u8 val, unsigned long reg)
  42 {
  43         writeb(val, esp->regs + (reg * 4UL));
  44 }
  45
  46 static u8 sun3x_esp_read8(struct esp *esp, unsigned long reg)
  47 {
  48         return readb(esp->regs + (reg * 4UL));
  49 }
  50
  51 static dma_addr_t sun3x_esp_map_single(struct esp *esp, void *buf,
  52                                       size_t sz, int dir)
  53 {
  54         return dma_map_single(esp->dev, buf, sz, dir);
  55 }
  56
  57 static int sun3x_esp_map_sg(struct esp *esp, struct scatterlist *sg,
  58                                   int num_sg, int dir)
  59 {
  60         return dma_map_sg(esp->dev, sg, num_sg, dir);
  61 }
  62
  63 static void sun3x_esp_unmap_single(struct esp *esp, dma_addr_t addr,
  64                                   size_t sz, int dir)
  65 {
  66         dma_unmap_single(esp->dev, addr, sz, dir);
  67 }
  68
  69 static void sun3x_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
  70                               int num_sg, int dir)
  71 {
  72         dma_unmap_sg(esp->dev, sg, num_sg, dir);
  73 }
  74
  75 static int sun3x_esp_irq_pending(struct esp *esp)
  76 {
  77         if (dma_read32(DMA_CSR) & (DMA_HNDL_INTR | DMA_HNDL_ERROR))
  78                 return 1;
  79         return 0;
  80 }
  81
  82 static void sun3x_esp_reset_dma(struct esp *esp)
  83 {
  84         u32 val;
  85
  86         val = dma_read32(DMA_CSR);
  87         dma_write32(val | DMA_RST_SCSI, DMA_CSR);
  88         dma_write32(val & ~DMA_RST_SCSI, DMA_CSR);
  89
  90         /* Enable interrupts.  */
  91         val = dma_read32(DMA_CSR);
  92         dma_write32(val | DMA_INT_ENAB, DMA_CSR);
  93 }
  94
  95 static void sun3x_esp_dma_drain(struct esp *esp)
  96 {
  97         u32 csr;
  98         int lim;
  99
 100         csr = dma_read32(DMA_CSR);
 101         if (!(csr & DMA_FIFO_ISDRAIN))
 102                 return;
 103
 104         dma_write32(csr | DMA_FIFO_STDRAIN, DMA_CSR);
 105
 106         lim = 1000;
 107         while (dma_read32(DMA_CSR) & DMA_FIFO_ISDRAIN) {
 108                 if (--lim == 0) {
 109                         printk(KERN_ALERT PFX "esp%d: DMA will not drain!\n",
 110                                esp->host->unique_id);
 111                         break;
 112                 }
 113                 udelay(1);
 114         }
 115 }
 116
 117 static void sun3x_esp_dma_invalidate(struct esp *esp)
 118 {
 119         u32 val;
 120         int lim;
 121
 122         lim = 1000;
 123         while ((val = dma_read32(DMA_CSR)) & DMA_PEND_READ) {
 124                 if (--lim == 0) {
 125                         printk(KERN_ALERT PFX "esp%d: DMA will not "
 126                                "invalidate!\n", esp->host->unique_id);
 127                         break;
 128                 }
 129                 udelay(1);
 130         }
 131
 132         val &= ~(DMA_ENABLE | DMA_ST_WRITE | DMA_BCNT_ENAB);
 133         val |= DMA_FIFO_INV;
 134         dma_write32(val, DMA_CSR);
 135         val &= ~DMA_FIFO_INV;
 136         dma_write32(val, DMA_CSR);
 137 }
 138
 139 static void sun3x_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count,
 140                                   u32 dma_count, int write, u8 cmd)
 141 {
 142         u32 csr;
 143
 144         BUG_ON(!(cmd & ESP_CMD_DMA));
 145
 146         sun3x_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
 147         sun3x_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
 148         csr = dma_read32(DMA_CSR);
 149         csr |= DMA_ENABLE;
 150         if (write)
 151                 csr |= DMA_ST_WRITE;
 152         else
 153                 csr &= ~DMA_ST_WRITE;
 154         dma_write32(csr, DMA_CSR);
 155         dma_write32(addr, DMA_ADDR);
 156
 157         scsi_esp_cmd(esp, cmd);
 158 }
 159
 160 static int sun3x_esp_dma_error(struct esp *esp)
 161 {
 162         u32 csr = dma_read32(DMA_CSR);
 163
 164         if (csr & DMA_HNDL_ERROR)
 165                 return 1;
 166
 167         return 0;
 168 }
 169
 170 static const struct esp_driver_ops sun3x_esp_ops = {
 171         .esp_write8     =       sun3x_esp_write8,
 172         .esp_read8      =       sun3x_esp_read8,
 173         .map_single     =       sun3x_esp_map_single,
 174         .map_sg         =       sun3x_esp_map_sg,
 175         .unmap_single   =       sun3x_esp_unmap_single,
 176         .unmap_sg       =       sun3x_esp_unmap_sg,
 177         .irq_pending    =       sun3x_esp_irq_pending,
 178         .reset_dma      =       sun3x_esp_reset_dma,
 179         .dma_drain      =       sun3x_esp_dma_drain,
 180         .dma_invalidate =       sun3x_esp_dma_invalidate,
 181         .send_dma_cmd   =       sun3x_esp_send_dma_cmd,
 182         .dma_error      =       sun3x_esp_dma_error,
 183 };
 184
 185 static int __devinit esp_sun3x_probe(struct platform_device *dev)
 186 {
 187         struct scsi_host_template *tpnt = &scsi_esp_template;
 188         struct Scsi_Host *host;
 189         struct esp *esp;
 190         struct resource *res;
 191         int err = -ENOMEM;
 192
 193         host = scsi_host_alloc(tpnt, sizeof(struct esp));
 194         if (!host)
 195                 goto fail;
 196
 197         host->max_id = 8;
 198         esp = shost_priv(host);
 199
 200         esp->host = host;
 201         esp->dev = dev;
 202         esp->ops = &sun3x_esp_ops;
 203
 204         res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 205         if (!res || !res->start)
 206                 goto fail_unlink;
 207
 208         esp->regs = ioremap_nocache(res->start, 0x20);
 209         if (!esp->regs)
 210                 goto fail_unmap_regs;
 211
 212         res = platform_get_resource(dev, IORESOURCE_MEM, 1);
 213         if (!res || !res->start)
 214                 goto fail_unmap_regs;
 215
 216         esp->dma_regs = ioremap_nocache(res->start, 0x10);
 217
 218         esp->command_block = dma_alloc_coherent(esp->dev, 16,
 219                                                 &esp->command_block_dma,
 220                                                 GFP_KERNEL);
 221         if (!esp->command_block)
 222                 goto fail_unmap_regs_dma;
 223
 224         host->irq = platform_get_irq(dev, 0);
 225         err = request_irq(host->irq, scsi_esp_intr, IRQF_SHARED,
 226                           "SUN3X ESP", esp);
 227         if (err < 0)
 228                 goto fail_unmap_command_block;
 229
 230         esp->scsi_id = 7;
 231         esp->host->this_id = esp->scsi_id;
 232         esp->scsi_id_mask = (1 << esp->scsi_id);
 233         esp->cfreq = 20000000;
 234
 235         dev_set_drvdata(&dev->dev, esp);
 236
 237         err = scsi_esp_register(esp, &dev->dev);
 238         if (err)
 239                 goto fail_free_irq;
 240
 241         return 0;
 242
 243 fail_free_irq:
 244         free_irq(host->irq, esp);
 245 fail_unmap_command_block:
 246         dma_free_coherent(esp->dev, 16,
 247                           esp->command_block,
 248                           esp->command_block_dma);
 249 fail_unmap_regs_dma:
 250         iounmap(esp->dma_regs);
 251 fail_unmap_regs:
 252         iounmap(esp->regs);
 253 fail_unlink:
 254         scsi_host_put(host);
 255 fail:
 256         return err;
 257 }
 258
 259 static int __devexit esp_sun3x_remove(struct platform_device *dev)
 260 {
 261         struct esp *esp = dev_get_drvdata(&dev->dev);
 262         unsigned int irq = esp->host->irq;
 263         u32 val;
 264
 265         scsi_esp_unregister(esp);
 266
 267         /* Disable interrupts.  */
 268         val = dma_read32(DMA_CSR);
 269         dma_write32(val & ~DMA_INT_ENAB, DMA_CSR);
 270
 271         free_irq(irq, esp);
 272         dma_free_coherent(esp->dev, 16,
 273                           esp->command_block,
 274                           esp->command_block_dma);
 275
 276         scsi_host_put(esp->host);
 277
 278         return 0;
 279 }
 280
 281 static struct platform_driver esp_sun3x_driver = {
 282         .probe          = esp_sun3x_probe,
 283         .remove         = __devexit_p(esp_sun3x_remove),
 284         .driver = {
 285                 .name   = "sun3x_esp",
 286                 .owner  = THIS_MODULE,
 287         },
 288 };
 289
 290 static int __init sun3x_esp_init(void)
 291 {
 292         return platform_driver_register(&esp_sun3x_driver);
 293 }
 294
 295 static void __exit sun3x_esp_exit(void)
 296 {
 297         platform_driver_unregister(&esp_sun3x_driver);
 298 }
 299
 300 MODULE_DESCRIPTION("Sun3x ESP SCSI driver");
 301 MODULE_AUTHOR("Thomas Bogendoerfer (tsbogend@alpha.franken.de)");
 302 MODULE_LICENSE("GPL");
 303 MODULE_VERSION(DRV_VERSION);
 304
 305 module_init(sun3x_esp_init);
 306 module_exit(sun3x_esp_exit);
 307 MODULE_ALIAS("platform:sun3x_esp");