linux/drivers/ata/pata_ixp4xx_cf.c
Junlin Yang c38ae56ee0 pata_ipx4xx_cf: Fix unsigned comparison with less than zero
The return from the call to platform_get_irq() is int, it can be
a negative error code, however this is being assigned to an unsigned
int variable 'irq', so making 'irq' an int, and change the position to
keep the code format.

./drivers/ata/pata_ixp4xx_cf.c:168:5-8:
WARNING: Unsigned expression compared with zero: irq > 0

Signed-off-by: Junlin Yang <yangjunlin@yulong.com>
Link: https://lore.kernel.org/r/20210409135426.1773-1-angkery@163.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-04-11 20:35:24 -06:00

208 lines
5.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* ixp4xx PATA/Compact Flash driver
* Copyright (C) 2006-07 Tower Technologies
* Author: Alessandro Zummo <a.zummo@towertech.it>
*
* An ATA driver to handle a Compact Flash connected
* to the ixp4xx expansion bus in TrueIDE mode. The CF
* must have it chip selects connected to two CS lines
* on the ixp4xx. In the irq is not available, you might
* want to modify both this driver and libata to run in
* polling mode.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/libata.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <scsi/scsi_host.h>
#define DRV_NAME "pata_ixp4xx_cf"
#define DRV_VERSION "0.2"
static int ixp4xx_set_mode(struct ata_link *link, struct ata_device **error)
{
struct ata_device *dev;
ata_for_each_dev(dev, link, ENABLED) {
ata_dev_info(dev, "configured for PIO0\n");
dev->pio_mode = XFER_PIO_0;
dev->xfer_mode = XFER_PIO_0;
dev->xfer_shift = ATA_SHIFT_PIO;
dev->flags |= ATA_DFLAG_PIO;
}
return 0;
}
static unsigned int ixp4xx_mmio_data_xfer(struct ata_queued_cmd *qc,
unsigned char *buf, unsigned int buflen, int rw)
{
unsigned int i;
unsigned int words = buflen >> 1;
u16 *buf16 = (u16 *) buf;
struct ata_port *ap = qc->dev->link->ap;
void __iomem *mmio = ap->ioaddr.data_addr;
struct ixp4xx_pata_data *data = dev_get_platdata(ap->host->dev);
/* set the expansion bus in 16bit mode and restore
* 8 bit mode after the transaction.
*/
*data->cs0_cfg &= ~(0x01);
udelay(100);
/* Transfer multiple of 2 bytes */
if (rw == READ)
for (i = 0; i < words; i++)
buf16[i] = readw(mmio);
else
for (i = 0; i < words; i++)
writew(buf16[i], mmio);
/* Transfer trailing 1 byte, if any. */
if (unlikely(buflen & 0x01)) {
u16 align_buf[1] = { 0 };
unsigned char *trailing_buf = buf + buflen - 1;
if (rw == READ) {
align_buf[0] = readw(mmio);
memcpy(trailing_buf, align_buf, 1);
} else {
memcpy(align_buf, trailing_buf, 1);
writew(align_buf[0], mmio);
}
words++;
}
udelay(100);
*data->cs0_cfg |= 0x01;
return words << 1;
}
static struct scsi_host_template ixp4xx_sht = {
ATA_PIO_SHT(DRV_NAME),
};
static struct ata_port_operations ixp4xx_port_ops = {
.inherits = &ata_sff_port_ops,
.sff_data_xfer = ixp4xx_mmio_data_xfer,
.cable_detect = ata_cable_40wire,
.set_mode = ixp4xx_set_mode,
};
static void ixp4xx_setup_port(struct ata_port *ap,
struct ixp4xx_pata_data *data,
unsigned long raw_cs0, unsigned long raw_cs1)
{
struct ata_ioports *ioaddr = &ap->ioaddr;
unsigned long raw_cmd = raw_cs0;
unsigned long raw_ctl = raw_cs1 + 0x06;
ioaddr->cmd_addr = data->cs0;
ioaddr->altstatus_addr = data->cs1 + 0x06;
ioaddr->ctl_addr = data->cs1 + 0x06;
ata_sff_std_ports(ioaddr);
#ifndef __ARMEB__
/* adjust the addresses to handle the address swizzling of the
* ixp4xx in little endian mode.
*/
*(unsigned long *)&ioaddr->data_addr ^= 0x02;
*(unsigned long *)&ioaddr->cmd_addr ^= 0x03;
*(unsigned long *)&ioaddr->altstatus_addr ^= 0x03;
*(unsigned long *)&ioaddr->ctl_addr ^= 0x03;
*(unsigned long *)&ioaddr->error_addr ^= 0x03;
*(unsigned long *)&ioaddr->feature_addr ^= 0x03;
*(unsigned long *)&ioaddr->nsect_addr ^= 0x03;
*(unsigned long *)&ioaddr->lbal_addr ^= 0x03;
*(unsigned long *)&ioaddr->lbam_addr ^= 0x03;
*(unsigned long *)&ioaddr->lbah_addr ^= 0x03;
*(unsigned long *)&ioaddr->device_addr ^= 0x03;
*(unsigned long *)&ioaddr->status_addr ^= 0x03;
*(unsigned long *)&ioaddr->command_addr ^= 0x03;
raw_cmd ^= 0x03;
raw_ctl ^= 0x03;
#endif
ata_port_desc(ap, "cmd 0x%lx ctl 0x%lx", raw_cmd, raw_ctl);
}
static int ixp4xx_pata_probe(struct platform_device *pdev)
{
struct resource *cs0, *cs1;
struct ata_host *host;
struct ata_port *ap;
struct ixp4xx_pata_data *data = dev_get_platdata(&pdev->dev);
int ret;
int irq;
cs0 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
cs1 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (!cs0 || !cs1)
return -EINVAL;
/* allocate host */
host = ata_host_alloc(&pdev->dev, 1);
if (!host)
return -ENOMEM;
/* acquire resources and fill host */
ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
if (ret)
return ret;
data->cs0 = devm_ioremap(&pdev->dev, cs0->start, 0x1000);
data->cs1 = devm_ioremap(&pdev->dev, cs1->start, 0x1000);
if (!data->cs0 || !data->cs1)
return -ENOMEM;
irq = platform_get_irq(pdev, 0);
if (irq > 0)
irq_set_irq_type(irq, IRQ_TYPE_EDGE_RISING);
else if (irq < 0)
return irq;
else
return -EINVAL;
/* Setup expansion bus chip selects */
*data->cs0_cfg = data->cs0_bits;
*data->cs1_cfg = data->cs1_bits;
ap = host->ports[0];
ap->ops = &ixp4xx_port_ops;
ap->pio_mask = ATA_PIO4;
ap->flags |= ATA_FLAG_NO_ATAPI;
ixp4xx_setup_port(ap, data, cs0->start, cs1->start);
ata_print_version_once(&pdev->dev, DRV_VERSION);
/* activate host */
return ata_host_activate(host, irq, ata_sff_interrupt, 0, &ixp4xx_sht);
}
static struct platform_driver ixp4xx_pata_platform_driver = {
.driver = {
.name = DRV_NAME,
},
.probe = ixp4xx_pata_probe,
.remove = ata_platform_remove_one,
};
module_platform_driver(ixp4xx_pata_platform_driver);
MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
MODULE_DESCRIPTION("low-level driver for ixp4xx Compact Flash PATA");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
MODULE_ALIAS("platform:" DRV_NAME);