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linux/drivers/scsi/sun3x_esp.c
Uwe Kleine-König e84bd0bb30 scsi: sun3x_esp: Convert to platform remove callback returning void 
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

In the error path emit an error message replacing the (less useful)
message by the core. Apart from the improved error message there is no
change in behaviour.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/5010d1a4f3d77eaa1114fa254c343c4f23313901.1701619134.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-12-05 21:51:37 -05:00

280 lines
6.3 KiB
C
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// 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 void 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);
}
static struct platform_driver esp_sun3x_driver = {
.probe = esp_sun3x_probe,
.remove_new = 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");
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