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