linux/drivers/ata/pata_sc1200.c
Lee Jones 160be1bc0b ata: pata_sc1200: sc1200_sht'Avoid overwriting initialised field in '
Fixes the following W=1 kernel build warning(s):

 drivers/ata/pata_sc1200.c:197:18: warning: initialized field overwritten [-Woverride-init]
 drivers/ata/pata_sc1200.c:197:18: note: (near initialization for ‘sc1200_sht.sg_tablesize’)

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Mark Lord <mlord@pobox.com>
Cc: linux-ide@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20210528090502.1799866-10-lee.jones@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-16 06:50:25 -06:00

258 lines
6.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* New ATA layer SC1200 driver Alan Cox <alan@lxorguk.ukuu.org.uk>
*
* TODO: Mode selection filtering
* TODO: Needs custom DMA cleanup code
*
* Based very heavily on
*
* linux/drivers/ide/pci/sc1200.c Version 0.91 28-Jan-2003
*
* Copyright (C) 2000-2002 Mark Lord <mlord@pobox.com>
* May be copied or modified under the terms of the GNU General Public License
*
* Development of this chipset driver was funded
* by the nice folks at National Semiconductor.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>
#define DRV_NAME "pata_sc1200"
#define DRV_VERSION "0.2.6"
#define SC1200_REV_A 0x00
#define SC1200_REV_B1 0x01
#define SC1200_REV_B3 0x02
#define SC1200_REV_C1 0x03
#define SC1200_REV_D1 0x04
/**
* sc1200_clock - PCI clock
*
* Return the PCI bus clocking for the SC1200 chipset configuration
* in use. We return 0 for 33MHz 1 for 48MHz and 2 for 66Mhz
*/
static int sc1200_clock(void)
{
/* Magic registers that give us the chipset data */
u8 chip_id = inb(0x903C);
u8 silicon_rev = inb(0x903D);
u16 pci_clock;
if (chip_id == 0x04 && silicon_rev < SC1200_REV_B1)
return 0; /* 33 MHz mode */
/* Clock generator configuration 0x901E its 8/9 are the PCI clocking
0/3 is 33Mhz 1 is 48 2 is 66 */
pci_clock = inw(0x901E);
pci_clock >>= 8;
pci_clock &= 0x03;
if (pci_clock == 3)
pci_clock = 0;
return pci_clock;
}
/**
* sc1200_set_piomode - PIO setup
* @ap: ATA interface
* @adev: device on the interface
*
* Set our PIO requirements. This is fairly simple on the SC1200
*/
static void sc1200_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
static const u32 pio_timings[4][5] = {
/* format0, 33Mhz */
{ 0x00009172, 0x00012171, 0x00020080, 0x00032010, 0x00040010 },
/* format1, 33Mhz */
{ 0xd1329172, 0x71212171, 0x30200080, 0x20102010, 0x00100010 },
/* format1, 48Mhz */
{ 0xfaa3f4f3, 0xc23232b2, 0x513101c1, 0x31213121, 0x10211021 },
/* format1, 66Mhz */
{ 0xfff4fff4, 0xf35353d3, 0x814102f1, 0x42314231, 0x11311131 }
};
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
u32 format;
unsigned int reg = 0x40 + 0x10 * ap->port_no;
int mode = adev->pio_mode - XFER_PIO_0;
pci_read_config_dword(pdev, reg + 4, &format);
format >>= 31;
format += sc1200_clock();
pci_write_config_dword(pdev, reg + 8 * adev->devno,
pio_timings[format][mode]);
}
/**
* sc1200_set_dmamode - DMA timing setup
* @ap: ATA interface
* @adev: Device being configured
*
* We cannot mix MWDMA and UDMA without reloading timings each switch
* master to slave.
*/
static void sc1200_set_dmamode(struct ata_port *ap, struct ata_device *adev)
{
static const u32 udma_timing[3][3] = {
{ 0x00921250, 0x00911140, 0x00911030 },
{ 0x00932470, 0x00922260, 0x00922140 },
{ 0x009436A1, 0x00933481, 0x00923261 }
};
static const u32 mwdma_timing[3][3] = {
{ 0x00077771, 0x00012121, 0x00002020 },
{ 0x000BBBB2, 0x00024241, 0x00013131 },
{ 0x000FFFF3, 0x00035352, 0x00015151 }
};
int clock = sc1200_clock();
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
unsigned int reg = 0x40 + 0x10 * ap->port_no;
int mode = adev->dma_mode;
u32 format;
if (mode >= XFER_UDMA_0)
format = udma_timing[clock][mode - XFER_UDMA_0];
else
format = mwdma_timing[clock][mode - XFER_MW_DMA_0];
if (adev->devno == 0) {
u32 timings;
pci_read_config_dword(pdev, reg + 4, &timings);
timings &= 0x80000000UL;
timings |= format;
pci_write_config_dword(pdev, reg + 4, timings);
} else
pci_write_config_dword(pdev, reg + 12, format);
}
/**
* sc1200_qc_issue - command issue
* @qc: command pending
*
* Called when the libata layer is about to issue a command. We wrap
* this interface so that we can load the correct ATA timings if
* necessary. Specifically we have a problem that there is only
* one MWDMA/UDMA bit.
*/
static unsigned int sc1200_qc_issue(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;
struct ata_device *adev = qc->dev;
struct ata_device *prev = ap->private_data;
/* See if the DMA settings could be wrong */
if (ata_dma_enabled(adev) && adev != prev && prev != NULL) {
/* Maybe, but do the channels match MWDMA/UDMA ? */
if ((ata_using_udma(adev) && !ata_using_udma(prev)) ||
(ata_using_udma(prev) && !ata_using_udma(adev)))
/* Switch the mode bits */
sc1200_set_dmamode(ap, adev);
}
return ata_bmdma_qc_issue(qc);
}
/**
* sc1200_qc_defer - implement serialization
* @qc: command
*
* Serialize command issue on this controller.
*/
static int sc1200_qc_defer(struct ata_queued_cmd *qc)
{
struct ata_host *host = qc->ap->host;
struct ata_port *alt = host->ports[1 ^ qc->ap->port_no];
int rc;
/* First apply the usual rules */
rc = ata_std_qc_defer(qc);
if (rc != 0)
return rc;
/* Now apply serialization rules. Only allow a command if the
other channel state machine is idle */
if (alt && alt->qc_active)
return ATA_DEFER_PORT;
return 0;
}
static struct scsi_host_template sc1200_sht = {
ATA_BASE_SHT(DRV_NAME),
.sg_tablesize = LIBATA_DUMB_MAX_PRD,
.dma_boundary = ATA_DMA_BOUNDARY,
};
static struct ata_port_operations sc1200_port_ops = {
.inherits = &ata_bmdma_port_ops,
.qc_prep = ata_bmdma_dumb_qc_prep,
.qc_issue = sc1200_qc_issue,
.qc_defer = sc1200_qc_defer,
.cable_detect = ata_cable_40wire,
.set_piomode = sc1200_set_piomode,
.set_dmamode = sc1200_set_dmamode,
};
/**
* sc1200_init_one - Initialise an SC1200
* @dev: PCI device
* @id: Entry in match table
*
* Just throw the needed data at the libata helper and it does all
* our work.
*/
static int sc1200_init_one(struct pci_dev *dev, const struct pci_device_id *id)
{
static const struct ata_port_info info = {
.flags = ATA_FLAG_SLAVE_POSS,
.pio_mask = ATA_PIO4,
.mwdma_mask = ATA_MWDMA2,
.udma_mask = ATA_UDMA2,
.port_ops = &sc1200_port_ops
};
const struct ata_port_info *ppi[] = { &info, NULL };
return ata_pci_bmdma_init_one(dev, ppi, &sc1200_sht, NULL, 0);
}
static const struct pci_device_id sc1200[] = {
{ PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_SCx200_IDE), },
{ },
};
static struct pci_driver sc1200_pci_driver = {
.name = DRV_NAME,
.id_table = sc1200,
.probe = sc1200_init_one,
.remove = ata_pci_remove_one,
#ifdef CONFIG_PM_SLEEP
.suspend = ata_pci_device_suspend,
.resume = ata_pci_device_resume,
#endif
};
module_pci_driver(sc1200_pci_driver);
MODULE_AUTHOR("Alan Cox, Mark Lord");
MODULE_DESCRIPTION("low-level driver for the NS/AMD SC1200");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, sc1200);
MODULE_VERSION(DRV_VERSION);