// 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)
{
const 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");