drivers/scsi/sun3x_esp.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* sun3x_esp.c: ESP front-end for Sun3x systems.
   3  *
   4  * Copyright (C) 2007,2008 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/gfp.h>
   9 #include <linux/types.h>
  10 #include <linux/delay.h>
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/dma-mapping.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/io.h>
  17
  18 #include <asm/sun3x.h>
  19 #include <asm/dma.h>
  20 #include <asm/dvma.h>
  21
  22 /* DMA controller reg offsets */
  23 #define DMA_CSR         0x00UL  /* rw  DMA control/status register    0x00   */
  24 #define DMA_ADDR        0x04UL  /* rw  DMA transfer address register  0x04   */
  25 #define DMA_COUNT       0x08UL  /* rw  DMA transfer count register    0x08   */
  26 #define DMA_TEST        0x0cUL  /* rw  DMA test/debug register        0x0c   */
  27
  28 #include <scsi/scsi_host.h>
  29
  30 #include "esp_scsi.h"
  31
  32 #define DRV_MODULE_NAME         "sun3x_esp"
  33 #define PFX DRV_MODULE_NAME     ": "
  34 #define DRV_VERSION             "1.000"
  35 #define DRV_MODULE_RELDATE      "Nov 1, 2007"
  36
  37 /*
  38  * m68k always assumes readl/writel operate on little endian
  39  * mmio space; this is wrong at least for Sun3x, so we
  40  * need to workaround this until a proper way is found
  41  */
  42 #if 0
  43 #define dma_read32(REG) \
  44         readl(esp->dma_regs + (REG))
  45 #define dma_write32(VAL, REG) \
  46         writel((VAL), esp->dma_regs + (REG))
  47 #else
  48 #define dma_read32(REG) \
  49         *(volatile u32 *)(esp->dma_regs + (REG))
  50 #define dma_write32(VAL, REG) \
  51         do { *(volatile u32 *)(esp->dma_regs + (REG)) = (VAL); } while (0)
  52 #endif
  53
  54 static void sun3x_esp_write8(struct esp *esp, u8 val, unsigned long reg)
  55 {
  56         writeb(val, esp->regs + (reg * 4UL));
  57 }
  58
  59 static u8 sun3x_esp_read8(struct esp *esp, unsigned long reg)
  60 {
  61         return readb(esp->regs + (reg * 4UL));
  62 }
  63
  64 static int sun3x_esp_irq_pending(struct esp *esp)
  65 {
  66         if (dma_read32(DMA_CSR) & (DMA_HNDL_INTR | DMA_HNDL_ERROR))
  67                 return 1;
  68         return 0;
  69 }
  70
  71 static void sun3x_esp_reset_dma(struct esp *esp)
  72 {
  73         u32 val;
  74
  75         val = dma_read32(DMA_CSR);
  76         dma_write32(val | DMA_RST_SCSI, DMA_CSR);
  77         dma_write32(val & ~DMA_RST_SCSI, DMA_CSR);
  78
  79         /* Enable interrupts.  */
  80         val = dma_read32(DMA_CSR);
  81         dma_write32(val | DMA_INT_ENAB, DMA_CSR);
  82 }
  83
  84 static void sun3x_esp_dma_drain(struct esp *esp)
  85 {
  86         u32 csr;
  87         int lim;
  88
  89         csr = dma_read32(DMA_CSR);
  90         if (!(csr & DMA_FIFO_ISDRAIN))
  91                 return;
  92
  93         dma_write32(csr | DMA_FIFO_STDRAIN, DMA_CSR);
  94
  95         lim = 1000;
  96         while (dma_read32(DMA_CSR) & DMA_FIFO_ISDRAIN) {
  97                 if (--lim == 0) {
  98                         printk(KERN_ALERT PFX "esp%d: DMA will not drain!\n",
  99                                esp->host->unique_id);
 100                         break;
 101                 }
 102                 udelay(1);
 103         }
 104 }
 105
 106 static void sun3x_esp_dma_invalidate(struct esp *esp)
 107 {
 108         u32 val;
 109         int lim;
 110
 111         lim = 1000;
 112         while ((val = dma_read32(DMA_CSR)) & DMA_PEND_READ) {
 113                 if (--lim == 0) {
 114                         printk(KERN_ALERT PFX "esp%d: DMA will not "
 115                                "invalidate!\n", esp->host->unique_id);
 116                         break;
 117                 }
 118                 udelay(1);
 119         }
 120
 121         val &= ~(DMA_ENABLE | DMA_ST_WRITE | DMA_BCNT_ENAB);
 122         val |= DMA_FIFO_INV;
 123         dma_write32(val, DMA_CSR);
 124         val &= ~DMA_FIFO_INV;
 125         dma_write32(val, DMA_CSR);
 126 }
 127
 128 static void sun3x_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count,
 129                                   u32 dma_count, int write, u8 cmd)
 130 {
 131         u32 csr;
 132
 133         BUG_ON(!(cmd & ESP_CMD_DMA));
 134
 135         sun3x_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
 136         sun3x_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
 137         csr = dma_read32(DMA_CSR);
 138         csr |= DMA_ENABLE;
 139         if (write)
 140                 csr |= DMA_ST_WRITE;
 141         else
 142                 csr &= ~DMA_ST_WRITE;
 143         dma_write32(csr, DMA_CSR);
 144         dma_write32(addr, DMA_ADDR);
 145
 146         scsi_esp_cmd(esp, cmd);
 147 }
 148
 149 static int sun3x_esp_dma_error(struct esp *esp)
 150 {
 151         u32 csr = dma_read32(DMA_CSR);
 152
 153         if (csr & DMA_HNDL_ERROR)
 154                 return 1;
 155
 156         return 0;
 157 }
 158
 159 static const struct esp_driver_ops sun3x_esp_ops = {
 160         .esp_write8     =       sun3x_esp_write8,
 161         .esp_read8      =       sun3x_esp_read8,
 162         .irq_pending    =       sun3x_esp_irq_pending,
 163         .reset_dma      =       sun3x_esp_reset_dma,
 164         .dma_drain      =       sun3x_esp_dma_drain,
 165         .dma_invalidate =       sun3x_esp_dma_invalidate,
 166         .send_dma_cmd   =       sun3x_esp_send_dma_cmd,
 167         .dma_error      =       sun3x_esp_dma_error,
 168 };
 169
 170 static int esp_sun3x_probe(struct platform_device *dev)
 171 {
 172         struct scsi_host_template *tpnt = &scsi_esp_template;
 173         struct Scsi_Host *host;
 174         struct esp *esp;
 175         struct resource *res;
 176         int err = -ENOMEM;
 177
 178         host = scsi_host_alloc(tpnt, sizeof(struct esp));
 179         if (!host)
 180                 goto fail;
 181
 182         host->max_id = 8;
 183         esp = shost_priv(host);
 184
 185         esp->host = host;
 186         esp->dev = &dev->dev;
 187         esp->ops = &sun3x_esp_ops;
 188
 189         res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 190         if (!res || !res->start)
 191                 goto fail_unlink;
 192
 193         esp->regs = ioremap(res->start, 0x20);
 194         if (!esp->regs)
 195                 goto fail_unmap_regs;
 196
 197         res = platform_get_resource(dev, IORESOURCE_MEM, 1);
 198         if (!res || !res->start)
 199                 goto fail_unmap_regs;
 200
 201         esp->dma_regs = ioremap(res->start, 0x10);
 202
 203         esp->command_block = dma_alloc_coherent(esp->dev, 16,
 204                                                 &esp->command_block_dma,
 205                                                 GFP_KERNEL);
 206         if (!esp->command_block)
 207                 goto fail_unmap_regs_dma;
 208
 209         host->irq = platform_get_irq(dev, 0);
 210         err = request_irq(host->irq, scsi_esp_intr, IRQF_SHARED,
 211                           "SUN3X ESP", esp);
 212         if (err < 0)
 213                 goto fail_unmap_command_block;
 214
 215         esp->scsi_id = 7;
 216         esp->host->this_id = esp->scsi_id;
 217         esp->scsi_id_mask = (1 << esp->scsi_id);
 218         esp->cfreq = 20000000;
 219
 220         dev_set_drvdata(&dev->dev, esp);
 221
 222         err = scsi_esp_register(esp);
 223         if (err)
 224                 goto fail_free_irq;
 225
 226         return 0;
 227
 228 fail_free_irq:
 229         free_irq(host->irq, esp);
 230 fail_unmap_command_block:
 231         dma_free_coherent(esp->dev, 16,
 232                           esp->command_block,
 233                           esp->command_block_dma);
 234 fail_unmap_regs_dma:
 235         iounmap(esp->dma_regs);
 236 fail_unmap_regs:
 237         iounmap(esp->regs);
 238 fail_unlink:
 239         scsi_host_put(host);
 240 fail:
 241         return err;
 242 }
 243
 244 static int esp_sun3x_remove(struct platform_device *dev)
 245 {
 246         struct esp *esp = dev_get_drvdata(&dev->dev);
 247         unsigned int irq = esp->host->irq;
 248         u32 val;
 249
 250         scsi_esp_unregister(esp);
 251
 252         /* Disable interrupts.  */
 253         val = dma_read32(DMA_CSR);
 254         dma_write32(val & ~DMA_INT_ENAB, DMA_CSR);
 255
 256         free_irq(irq, esp);
 257         dma_free_coherent(esp->dev, 16,
 258                           esp->command_block,
 259                           esp->command_block_dma);
 260
 261         scsi_host_put(esp->host);
 262
 263         return 0;
 264 }
 265
 266 static struct platform_driver esp_sun3x_driver = {
 267         .probe          = esp_sun3x_probe,
 268         .remove         = esp_sun3x_remove,
 269         .driver = {
 270                 .name   = "sun3x_esp",
 271         },
 272 };
 273 module_platform_driver(esp_sun3x_driver);
 274
 275 MODULE_DESCRIPTION("Sun3x ESP SCSI driver");
 276 MODULE_AUTHOR("Thomas Bogendoerfer (tsbogend@alpha.franken.de)");
 277 MODULE_LICENSE("GPL");
 278 MODULE_VERSION(DRV_VERSION);
 279 MODULE_ALIAS("platform:sun3x_esp");