a3000.c
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <asm/page.h>
#include <asm/amigaints.h>
#include <asm/amigahw.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_tcq.h>
#include "wd33c93.h"
#include "a3000.h"
struct a3000_hostdata {
struct WD33C93_hostdata wh;
struct a3000_scsiregs *regs;
struct device *dev;
};
#define DMA_DIR(d) ((d == DATA_OUT_DIR) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
static irqreturn_t a3000_intr(int irq, void *data)
{
struct Scsi_Host *instance = data;
struct a3000_hostdata *hdata = shost_priv(instance);
unsigned int status = hdata->regs->ISTR;
unsigned long flags;
if (!(status & ISTR_INT_P))
return IRQ_NONE;
if (status & ISTR_INTS) {
spin_lock_irqsave(instance->host_lock, flags);
wd33c93_intr(instance);
spin_unlock_irqrestore(instance->host_lock, flags);
return IRQ_HANDLED;
}
pr_warn("Non-serviced A3000 SCSI-interrupt? ISTR = %02x\n", status);
return IRQ_NONE;
}
static int dma_setup(struct scsi_cmnd *cmd, int dir_in)
{
struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(cmd);
unsigned long len = scsi_pointer->this_residual;
struct Scsi_Host *instance = cmd->device->host;
struct a3000_hostdata *hdata = shost_priv(instance);
struct WD33C93_hostdata *wh = &hdata->wh;
struct a3000_scsiregs *regs = hdata->regs;
unsigned short cntr = CNTR_PDMD | CNTR_INTEN;
dma_addr_t addr;
addr = dma_map_single(hdata->dev, scsi_pointer->ptr,
len, DMA_DIR(dir_in));
if (dma_mapping_error(hdata->dev, addr)) {
dev_warn(hdata->dev, "cannot map SCSI data block %p\n",
scsi_pointer->ptr);
return 1;
}
scsi_pointer->dma_handle = addr;
/*
* if the physical address has the wrong alignment, or if
* physical address is bad, or if it is a write and at the
* end of a physical memory chunk, then allocate a bounce
* buffer
* MSch 20220629 - only wrong alignment tested - bounce
* buffer returned by kmalloc is guaranteed to be aligned
*/
if (addr & A3000_XFER_MASK) {
WARN_ONCE(1, "Invalid alignment for DMA!");
/* drop useless mapping */
dma_unmap_single(hdata->dev, scsi_pointer->dma_handle,
scsi_pointer->this_residual,
DMA_DIR(dir_in));
wh->dma_bounce_len = (scsi_pointer->this_residual + 511) & ~0x1ff;
wh->dma_bounce_buffer = kmalloc(wh->dma_bounce_len,
GFP_KERNEL);
/* can't allocate memory; use PIO */
if (!wh->dma_bounce_buffer) {
wh->dma_bounce_len = 0;
scsi_pointer->dma_handle = (dma_addr_t) NULL;
return 1;
}
if (!dir_in) {
/* copy to bounce buffer for a write */
memcpy(wh->dma_bounce_buffer, scsi_pointer->ptr,
scsi_pointer->this_residual);
}
addr = dma_map_single(hdata->dev, scsi_pointer->ptr,
len, DMA_DIR(dir_in));
if (dma_mapping_error(hdata->dev, addr)) {
dev_warn(hdata->dev,
"cannot map SCSI data block %p\n",
scsi_pointer->ptr);
return 1;
}
scsi_pointer->dma_handle = addr;
}
/* setup dma direction */
if (!dir_in)
cntr |= CNTR_DDIR;
/* remember direction */
wh->dma_dir = dir_in;
regs->CNTR = cntr;
/* setup DMA *physical* address */
regs->ACR = addr;
/* no more cache flush here - dma_map_single() takes care */
/* start DMA */
mb(); /* make sure setup is completed */
regs->ST_DMA = 1;
mb(); /* make sure DMA has started before next IO */
/* return success */
return 0;
}
static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
int status)
{
struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(SCpnt);
struct a3000_hostdata *hdata = shost_priv(instance);
struct WD33C93_hostdata *wh = &hdata->wh;
struct a3000_scsiregs *regs = hdata->regs;
/* disable SCSI interrupts */
unsigned short cntr = CNTR_PDMD;
if (!wh->dma_dir)
cntr |= CNTR_DDIR;
regs->CNTR = cntr;
mb(); /* make sure CNTR is updated before next IO */
/* flush if we were reading */
if (wh->dma_dir) {
regs->FLUSH = 1;
mb(); /* don't allow prefetch */
while (!(regs->ISTR & ISTR_FE_FLG))
barrier();
mb(); /* no IO until FLUSH is done */
}
/* clear a possible interrupt */
/* I think that this CINT is only necessary if you are
* using the terminal count features. HM 7 Mar 1994
*/
regs->CINT = 1;
/* stop DMA */
regs->SP_DMA = 1;
mb(); /* make sure DMA is stopped before next IO */
/* restore the CONTROL bits (minus the direction flag) */
regs->CNTR = CNTR_PDMD | CNTR_INTEN;
mb(); /* make sure CNTR is updated before next IO */
dma_unmap_single(hdata->dev, scsi_pointer->dma_handle,
scsi_pointer->this_residual,
DMA_DIR(wh->dma_dir));
/* copy from a bounce buffer, if necessary */
if (status && wh->dma_bounce_buffer) {
if (SCpnt) {
if (wh->dma_dir && SCpnt)
memcpy(scsi_pointer->ptr, wh->dma_bounce_buffer,
scsi_pointer->this_residual);
kfree(wh->dma_bounce_buffer);
wh->dma_bounce_buffer = NULL;
wh->dma_bounce_len = 0;
} else {
kfree(wh->dma_bounce_buffer);
wh->dma_bounce_buffer = NULL;
wh->dma_bounce_len = 0;
}
}
}
static const struct scsi_host_template amiga_a3000_scsi_template = {
.module = THIS_MODULE,
.name = "Amiga 3000 built-in SCSI",
.show_info = wd33c93_show_info,
.write_info = wd33c93_write_info,
.proc_name = "A3000",
.queuecommand = wd33c93_queuecommand,
.eh_abort_handler = wd33c93_abort,
.eh_host_reset_handler = wd33c93_host_reset,
.can_queue = CAN_QUEUE,
.this_id = 7,
.sg_tablesize = SG_ALL,
.cmd_per_lun = CMD_PER_LUN,
.cmd_size = sizeof(struct scsi_pointer),
};
static int __init amiga_a3000_scsi_probe(struct platform_device *pdev)
{
struct resource *res;
struct Scsi_Host *instance;
int error;
struct a3000_scsiregs *regs;
wd33c93_regs wdregs;
struct a3000_hostdata *hdata;
if (dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32))) {
dev_warn(&pdev->dev, "cannot use 32 bit DMA\n");
return -ENODEV;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENODEV;
if (!request_mem_region(res->start, resource_size(res), "wd33c93"))
return -EBUSY;
instance = scsi_host_alloc(&amiga_a3000_scsi_template,
sizeof(struct a3000_hostdata));
if (!instance) {
error = -ENOMEM;
goto fail_alloc;
}
instance->irq = IRQ_AMIGA_PORTS;
regs = ZTWO_VADDR(res->start);
regs->DAWR = DAWR_A3000;
wdregs.SASR = ®s->SASR;
wdregs.SCMD = ®s->SCMD;
hdata = shost_priv(instance);
hdata->dev = &pdev->dev;
hdata->wh.no_sync = 0xff;
hdata->wh.fast = 0;
hdata->wh.dma_mode = CTRL_DMA;
hdata->regs = regs;
wd33c93_init(instance, wdregs, dma_setup, dma_stop, WD33C93_FS_12_15);
error = request_irq(IRQ_AMIGA_PORTS, a3000_intr, IRQF_SHARED,
"A3000 SCSI", instance);
if (error)
goto fail_irq;
regs->CNTR = CNTR_PDMD | CNTR_INTEN;
error = scsi_add_host(instance, NULL);
if (error)
goto fail_host;
platform_set_drvdata(pdev, instance);
scsi_scan_host(instance);
return 0;
fail_host:
free_irq(IRQ_AMIGA_PORTS, instance);
fail_irq:
scsi_host_put(instance);
fail_alloc:
release_mem_region(res->start, resource_size(res));
return error;
}
static void __exit amiga_a3000_scsi_remove(struct platform_device *pdev)
{
struct Scsi_Host *instance = platform_get_drvdata(pdev);
struct a3000_hostdata *hdata = shost_priv(instance);
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
hdata->regs->CNTR = 0;
scsi_remove_host(instance);
free_irq(IRQ_AMIGA_PORTS, instance);
scsi_host_put(instance);
release_mem_region(res->start, resource_size(res));
}
static struct platform_driver amiga_a3000_scsi_driver = {
.remove_new = __exit_p(amiga_a3000_scsi_remove),
.driver = {
.name = "amiga-a3000-scsi",
},
};
module_platform_driver_probe(amiga_a3000_scsi_driver, amiga_a3000_scsi_probe);
MODULE_DESCRIPTION("Amiga 3000 built-in SCSI");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:amiga-a3000-scsi");