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 const 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 = err = platform_get_irq(dev, 0); 210 if (err < 0) 211 goto fail_unmap_command_block; 212 err = request_irq(host->irq, scsi_esp_intr, IRQF_SHARED, 213 "SUN3X ESP", esp); 214 if (err < 0) 215 goto fail_unmap_command_block; 216 217 esp->scsi_id = 7; 218 esp->host->this_id = esp->scsi_id; 219 esp->scsi_id_mask = (1 << esp->scsi_id); 220 esp->cfreq = 20000000; 221 222 dev_set_drvdata(&dev->dev, esp); 223 224 err = scsi_esp_register(esp); 225 if (err) 226 goto fail_free_irq; 227 228 return 0; 229 230 fail_free_irq: 231 free_irq(host->irq, esp); 232 fail_unmap_command_block: 233 dma_free_coherent(esp->dev, 16, 234 esp->command_block, 235 esp->command_block_dma); 236 fail_unmap_regs_dma: 237 iounmap(esp->dma_regs); 238 fail_unmap_regs: 239 iounmap(esp->regs); 240 fail_unlink: 241 scsi_host_put(host); 242 fail: 243 return err; 244 } 245 246 static int esp_sun3x_remove(struct platform_device *dev) 247 { 248 struct esp *esp = dev_get_drvdata(&dev->dev); 249 unsigned int irq = esp->host->irq; 250 u32 val; 251 252 scsi_esp_unregister(esp); 253 254 /* Disable interrupts. */ 255 val = dma_read32(DMA_CSR); 256 dma_write32(val & ~DMA_INT_ENAB, DMA_CSR); 257 258 free_irq(irq, esp); 259 dma_free_coherent(esp->dev, 16, 260 esp->command_block, 261 esp->command_block_dma); 262 263 scsi_host_put(esp->host); 264 265 return 0; 266 } 267 268 static struct platform_driver esp_sun3x_driver = { 269 .probe = esp_sun3x_probe, 270 .remove = esp_sun3x_remove, 271 .driver = { 272 .name = "sun3x_esp", 273 }, 274 }; 275 module_platform_driver(esp_sun3x_driver); 276 277 MODULE_DESCRIPTION("Sun3x ESP SCSI driver"); 278 MODULE_AUTHOR("Thomas Bogendoerfer (tsbogend@alpha.franken.de)"); 279 MODULE_LICENSE("GPL"); 280 MODULE_VERSION(DRV_VERSION); 281 MODULE_ALIAS("platform:sun3x_esp"); 282