diff options
Diffstat (limited to 'drivers/scsi/sun3x_esp.c')
| -rw-r--r-- | drivers/scsi/sun3x_esp.c | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/drivers/scsi/sun3x_esp.c b/drivers/scsi/sun3x_esp.c new file mode 100644 index 000000000..d3489ac7a --- /dev/null +++ b/drivers/scsi/sun3x_esp.c @@ -0,0 +1,281 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* sun3x_esp.c: ESP front-end for Sun3x systems. + * + * Copyright (C) 2007,2008 Thomas Bogendoerfer (tsbogend@alpha.franken.de) + */ + +#include <linux/kernel.h> +#include <linux/gfp.h> +#include <linux/types.h> +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/dma-mapping.h> +#include <linux/interrupt.h> +#include <linux/io.h> + +#include <asm/sun3x.h> +#include <asm/dma.h> +#include <asm/dvma.h> + +/* DMA controller reg offsets */ +#define DMA_CSR 0x00UL /* rw DMA control/status register 0x00 */ +#define DMA_ADDR 0x04UL /* rw DMA transfer address register 0x04 */ +#define DMA_COUNT 0x08UL /* rw DMA transfer count register 0x08 */ +#define DMA_TEST 0x0cUL /* rw DMA test/debug register 0x0c */ + +#include <scsi/scsi_host.h> + +#include "esp_scsi.h" + +#define DRV_MODULE_NAME "sun3x_esp" +#define PFX DRV_MODULE_NAME ": " +#define DRV_VERSION "1.000" +#define DRV_MODULE_RELDATE "Nov 1, 2007" + +/* + * m68k always assumes readl/writel operate on little endian + * mmio space; this is wrong at least for Sun3x, so we + * need to workaround this until a proper way is found + */ +#if 0 +#define dma_read32(REG) \ + readl(esp->dma_regs + (REG)) +#define dma_write32(VAL, REG) \ + writel((VAL), esp->dma_regs + (REG)) +#else +#define dma_read32(REG) \ + *(volatile u32 *)(esp->dma_regs + (REG)) +#define dma_write32(VAL, REG) \ + do { *(volatile u32 *)(esp->dma_regs + (REG)) = (VAL); } while (0) +#endif + +static void sun3x_esp_write8(struct esp *esp, u8 val, unsigned long reg) +{ + writeb(val, esp->regs + (reg * 4UL)); +} + +static u8 sun3x_esp_read8(struct esp *esp, unsigned long reg) +{ + return readb(esp->regs + (reg * 4UL)); +} + +static int sun3x_esp_irq_pending(struct esp *esp) +{ + if (dma_read32(DMA_CSR) & (DMA_HNDL_INTR | DMA_HNDL_ERROR)) + return 1; + return 0; +} + +static void sun3x_esp_reset_dma(struct esp *esp) +{ + u32 val; + + val = dma_read32(DMA_CSR); + dma_write32(val | DMA_RST_SCSI, DMA_CSR); + dma_write32(val & ~DMA_RST_SCSI, DMA_CSR); + + /* Enable interrupts. */ + val = dma_read32(DMA_CSR); + dma_write32(val | DMA_INT_ENAB, DMA_CSR); +} + +static void sun3x_esp_dma_drain(struct esp *esp) +{ + u32 csr; + int lim; + + csr = dma_read32(DMA_CSR); + if (!(csr & DMA_FIFO_ISDRAIN)) + return; + + dma_write32(csr | DMA_FIFO_STDRAIN, DMA_CSR); + + lim = 1000; + while (dma_read32(DMA_CSR) & DMA_FIFO_ISDRAIN) { + if (--lim == 0) { + printk(KERN_ALERT PFX "esp%d: DMA will not drain!\n", + esp->host->unique_id); + break; + } + udelay(1); + } +} + +static void sun3x_esp_dma_invalidate(struct esp *esp) +{ + u32 val; + int lim; + + lim = 1000; + while ((val = dma_read32(DMA_CSR)) & DMA_PEND_READ) { + if (--lim == 0) { + printk(KERN_ALERT PFX "esp%d: DMA will not " + "invalidate!\n", esp->host->unique_id); + break; + } + udelay(1); + } + + val &= ~(DMA_ENABLE | DMA_ST_WRITE | DMA_BCNT_ENAB); + val |= DMA_FIFO_INV; + dma_write32(val, DMA_CSR); + val &= ~DMA_FIFO_INV; + dma_write32(val, DMA_CSR); +} + +static void sun3x_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count, + u32 dma_count, int write, u8 cmd) +{ + u32 csr; + + BUG_ON(!(cmd & ESP_CMD_DMA)); + + sun3x_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW); + sun3x_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED); + csr = dma_read32(DMA_CSR); + csr |= DMA_ENABLE; + if (write) + csr |= DMA_ST_WRITE; + else + csr &= ~DMA_ST_WRITE; + dma_write32(csr, DMA_CSR); + dma_write32(addr, DMA_ADDR); + + scsi_esp_cmd(esp, cmd); +} + +static int sun3x_esp_dma_error(struct esp *esp) +{ + u32 csr = dma_read32(DMA_CSR); + + if (csr & DMA_HNDL_ERROR) + return 1; + + return 0; +} + +static const struct esp_driver_ops sun3x_esp_ops = { + .esp_write8 = sun3x_esp_write8, + .esp_read8 = sun3x_esp_read8, + .irq_pending = sun3x_esp_irq_pending, + .reset_dma = sun3x_esp_reset_dma, + .dma_drain = sun3x_esp_dma_drain, + .dma_invalidate = sun3x_esp_dma_invalidate, + .send_dma_cmd = sun3x_esp_send_dma_cmd, + .dma_error = sun3x_esp_dma_error, +}; + +static int esp_sun3x_probe(struct platform_device *dev) +{ + struct scsi_host_template *tpnt = &scsi_esp_template; + struct Scsi_Host *host; + struct esp *esp; + struct resource *res; + int err = -ENOMEM; + + host = scsi_host_alloc(tpnt, sizeof(struct esp)); + if (!host) + goto fail; + + host->max_id = 8; + esp = shost_priv(host); + + esp->host = host; + esp->dev = &dev->dev; + esp->ops = &sun3x_esp_ops; + + res = platform_get_resource(dev, IORESOURCE_MEM, 0); + if (!res || !res->start) + goto fail_unlink; + + esp->regs = ioremap(res->start, 0x20); + if (!esp->regs) + goto fail_unmap_regs; + + res = platform_get_resource(dev, IORESOURCE_MEM, 1); + if (!res || !res->start) + goto fail_unmap_regs; + + esp->dma_regs = ioremap(res->start, 0x10); + + esp->command_block = dma_alloc_coherent(esp->dev, 16, + &esp->command_block_dma, + GFP_KERNEL); + if (!esp->command_block) + goto fail_unmap_regs_dma; + + host->irq = err = platform_get_irq(dev, 0); + if (err < 0) + goto fail_unmap_command_block; + err = request_irq(host->irq, scsi_esp_intr, IRQF_SHARED, + "SUN3X ESP", esp); + if (err < 0) + goto fail_unmap_command_block; + + esp->scsi_id = 7; + esp->host->this_id = esp->scsi_id; + esp->scsi_id_mask = (1 << esp->scsi_id); + esp->cfreq = 20000000; + + dev_set_drvdata(&dev->dev, esp); + + err = scsi_esp_register(esp); + if (err) + goto fail_free_irq; + + return 0; + +fail_free_irq: + free_irq(host->irq, esp); +fail_unmap_command_block: + dma_free_coherent(esp->dev, 16, + esp->command_block, + esp->command_block_dma); +fail_unmap_regs_dma: + iounmap(esp->dma_regs); +fail_unmap_regs: + iounmap(esp->regs); +fail_unlink: + scsi_host_put(host); +fail: + return err; +} + +static int esp_sun3x_remove(struct platform_device *dev) +{ + struct esp *esp = dev_get_drvdata(&dev->dev); + unsigned int irq = esp->host->irq; + u32 val; + + scsi_esp_unregister(esp); + + /* Disable interrupts. */ + val = dma_read32(DMA_CSR); + dma_write32(val & ~DMA_INT_ENAB, DMA_CSR); + + free_irq(irq, esp); + dma_free_coherent(esp->dev, 16, + esp->command_block, + esp->command_block_dma); + + scsi_host_put(esp->host); + + return 0; +} + +static struct platform_driver esp_sun3x_driver = { + .probe = esp_sun3x_probe, + .remove = esp_sun3x_remove, + .driver = { + .name = "sun3x_esp", + }, +}; +module_platform_driver(esp_sun3x_driver); + +MODULE_DESCRIPTION("Sun3x ESP SCSI driver"); +MODULE_AUTHOR("Thomas Bogendoerfer (tsbogend@alpha.franken.de)"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(DRV_VERSION); +MODULE_ALIAS("platform:sun3x_esp"); |