kernel-ark/drivers/ata/pata_platform.c
Tejun Heo c7087652e1 libata-sff: clean up BMDMA initialization
When BMDMA initialization failed or BMDMA was not available for
whatever reason, bmdma_addr was left at zero and used as an indication
that BMDMA shouldn't be used.  This leads to the following problems.

p1. For BMDMA drivers which don't use traditional BMDMA register,
    ata_bmdma_mode_filter() incorrectly inhibits DMA modes.  Those
    drivers either have to inherit from ata_sff_port_ops or clear
    ->mode_filter explicitly.

p2. non-BMDMA drivers call into BMDMA PRD table allocation.  It
    doesn't actually allocate PRD table if bmdma_addr is not
    initialized but is still confusing.

p3. For BMDMA drivers which don't use traditional BMDMA register, some
    methods might not be invoked as expected (e.g. bmdma_stop from
    ata_sff_post_internal_cmd()).

p4. SFF drivers w/ custom DMA interface implement noop BMDMA ops
    worrying libata core might call into one of them.

These problems are caused by the muddy line between SFF and BMDMA and
the assumption that all BMDMA controllers initialize bmdma_addr.

This patch fixes p1 and p2 by removing the bmdma_addr assumption and
moving prd allocation to BMDMA port start.  Later patches will fix the
remaining issues.

This patch improves BMDMA initialization such that

* When BMDMA register initialization fails, falls back to PIO instead
  of failing.  ata_pci_bmdma_init() never fails now.

* When ata_pci_bmdma_init() falls back to PIO, it clears
  ap->mwdma_mask and udma_mask instead of depending on
  ata_bmdma_mode_filter().  This makes ata_bmdma_mode_filter()
  unnecessary thus resolving p1.

* ata_port_start() which actually is BMDMA specific is moved to
  ata_bmdma_port_start().  ata_port_start() and ata_sff_port_start()
  are killed.

* ata_sff_port_start32() is moved and renamed to
  ata_bmdma_port_start32().

Drivers which no longer call into PRD table allocation are...

  pdc_adma, sata_inic162x, sata_qstor, sata_sx4, pata_cmd640 and all
  drivers which inherit from ata_sff_port_ops.

pata_icside sets ->port_start to ATA_OP_NULL as it doesn't need PRD
but is a BMDMA controller and doesn't have custom port_start like
other such controllers.

Note that with the previous patch which makes all and only BMDMA
drivers inherit from ata_bmdma_port_ops, this change doesn't break
drivers which need PRD table.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2010-05-19 13:32:19 -04:00

278 lines
7.3 KiB
C

/*
* Generic platform device PATA driver
*
* Copyright (C) 2006 - 2007 Paul Mundt
*
* Based on pata_pcmcia:
*
* Copyright 2005-2006 Red Hat Inc, all rights reserved.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <scsi/scsi_host.h>
#include <linux/ata.h>
#include <linux/libata.h>
#include <linux/platform_device.h>
#include <linux/ata_platform.h>
#define DRV_NAME "pata_platform"
#define DRV_VERSION "1.2"
static int pio_mask = 1;
/*
* Provide our own set_mode() as we don't want to change anything that has
* already been configured..
*/
static int pata_platform_set_mode(struct ata_link *link, struct ata_device **unused)
{
struct ata_device *dev;
ata_for_each_dev(dev, link, ENABLED) {
/* We don't really care */
dev->pio_mode = dev->xfer_mode = XFER_PIO_0;
dev->xfer_shift = ATA_SHIFT_PIO;
dev->flags |= ATA_DFLAG_PIO;
ata_dev_printk(dev, KERN_INFO, "configured for PIO\n");
}
return 0;
}
static struct scsi_host_template pata_platform_sht = {
ATA_PIO_SHT(DRV_NAME),
};
static struct ata_port_operations pata_platform_port_ops = {
.inherits = &ata_sff_port_ops,
.sff_data_xfer = ata_sff_data_xfer_noirq,
.cable_detect = ata_cable_unknown,
.set_mode = pata_platform_set_mode,
};
static void pata_platform_setup_port(struct ata_ioports *ioaddr,
unsigned int shift)
{
/* Fixup the port shift for platforms that need it */
ioaddr->data_addr = ioaddr->cmd_addr + (ATA_REG_DATA << shift);
ioaddr->error_addr = ioaddr->cmd_addr + (ATA_REG_ERR << shift);
ioaddr->feature_addr = ioaddr->cmd_addr + (ATA_REG_FEATURE << shift);
ioaddr->nsect_addr = ioaddr->cmd_addr + (ATA_REG_NSECT << shift);
ioaddr->lbal_addr = ioaddr->cmd_addr + (ATA_REG_LBAL << shift);
ioaddr->lbam_addr = ioaddr->cmd_addr + (ATA_REG_LBAM << shift);
ioaddr->lbah_addr = ioaddr->cmd_addr + (ATA_REG_LBAH << shift);
ioaddr->device_addr = ioaddr->cmd_addr + (ATA_REG_DEVICE << shift);
ioaddr->status_addr = ioaddr->cmd_addr + (ATA_REG_STATUS << shift);
ioaddr->command_addr = ioaddr->cmd_addr + (ATA_REG_CMD << shift);
}
/**
* __pata_platform_probe - attach a platform interface
* @dev: device
* @io_res: Resource representing I/O base
* @ctl_res: Resource representing CTL base
* @irq_res: Resource representing IRQ and its flags
* @ioport_shift: I/O port shift
* @__pio_mask: PIO mask
*
* Register a platform bus IDE interface. Such interfaces are PIO and we
* assume do not support IRQ sharing.
*
* Platform devices are expected to contain at least 2 resources per port:
*
* - I/O Base (IORESOURCE_IO or IORESOURCE_MEM)
* - CTL Base (IORESOURCE_IO or IORESOURCE_MEM)
*
* and optionally:
*
* - IRQ (IORESOURCE_IRQ)
*
* If the base resources are both mem types, the ioremap() is handled
* here. For IORESOURCE_IO, it's assumed that there's no remapping
* necessary.
*
* If no IRQ resource is present, PIO polling mode is used instead.
*/
int __devinit __pata_platform_probe(struct device *dev,
struct resource *io_res,
struct resource *ctl_res,
struct resource *irq_res,
unsigned int ioport_shift,
int __pio_mask)
{
struct ata_host *host;
struct ata_port *ap;
unsigned int mmio;
int irq = 0;
int irq_flags = 0;
/*
* Check for MMIO
*/
mmio = (( io_res->flags == IORESOURCE_MEM) &&
(ctl_res->flags == IORESOURCE_MEM));
/*
* And the IRQ
*/
if (irq_res && irq_res->start > 0) {
irq = irq_res->start;
irq_flags = irq_res->flags;
}
/*
* Now that that's out of the way, wire up the port..
*/
host = ata_host_alloc(dev, 1);
if (!host)
return -ENOMEM;
ap = host->ports[0];
ap->ops = &pata_platform_port_ops;
ap->pio_mask = __pio_mask;
ap->flags |= ATA_FLAG_SLAVE_POSS;
/*
* Use polling mode if there's no IRQ
*/
if (!irq) {
ap->flags |= ATA_FLAG_PIO_POLLING;
ata_port_desc(ap, "no IRQ, using PIO polling");
}
/*
* Handle the MMIO case
*/
if (mmio) {
ap->ioaddr.cmd_addr = devm_ioremap(dev, io_res->start,
resource_size(io_res));
ap->ioaddr.ctl_addr = devm_ioremap(dev, ctl_res->start,
resource_size(ctl_res));
} else {
ap->ioaddr.cmd_addr = devm_ioport_map(dev, io_res->start,
resource_size(io_res));
ap->ioaddr.ctl_addr = devm_ioport_map(dev, ctl_res->start,
resource_size(ctl_res));
}
if (!ap->ioaddr.cmd_addr || !ap->ioaddr.ctl_addr) {
dev_err(dev, "failed to map IO/CTL base\n");
return -ENOMEM;
}
ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
pata_platform_setup_port(&ap->ioaddr, ioport_shift);
ata_port_desc(ap, "%s cmd 0x%llx ctl 0x%llx", mmio ? "mmio" : "ioport",
(unsigned long long)io_res->start,
(unsigned long long)ctl_res->start);
/* activate */
return ata_host_activate(host, irq, irq ? ata_sff_interrupt : NULL,
irq_flags, &pata_platform_sht);
}
EXPORT_SYMBOL_GPL(__pata_platform_probe);
/**
* __pata_platform_remove - unplug a platform interface
* @dev: device
*
* A platform bus ATA device has been unplugged. Perform the needed
* cleanup. Also called on module unload for any active devices.
*/
int __pata_platform_remove(struct device *dev)
{
struct ata_host *host = dev_get_drvdata(dev);
ata_host_detach(host);
return 0;
}
EXPORT_SYMBOL_GPL(__pata_platform_remove);
static int __devinit pata_platform_probe(struct platform_device *pdev)
{
struct resource *io_res;
struct resource *ctl_res;
struct resource *irq_res;
struct pata_platform_info *pp_info = pdev->dev.platform_data;
/*
* Simple resource validation ..
*/
if ((pdev->num_resources != 3) && (pdev->num_resources != 2)) {
dev_err(&pdev->dev, "invalid number of resources\n");
return -EINVAL;
}
/*
* Get the I/O base first
*/
io_res = platform_get_resource(pdev, IORESOURCE_IO, 0);
if (io_res == NULL) {
io_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (unlikely(io_res == NULL))
return -EINVAL;
}
/*
* Then the CTL base
*/
ctl_res = platform_get_resource(pdev, IORESOURCE_IO, 1);
if (ctl_res == NULL) {
ctl_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (unlikely(ctl_res == NULL))
return -EINVAL;
}
/*
* And the IRQ
*/
irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (irq_res)
irq_res->flags = pp_info ? pp_info->irq_flags : 0;
return __pata_platform_probe(&pdev->dev, io_res, ctl_res, irq_res,
pp_info ? pp_info->ioport_shift : 0,
pio_mask);
}
static int __devexit pata_platform_remove(struct platform_device *pdev)
{
return __pata_platform_remove(&pdev->dev);
}
static struct platform_driver pata_platform_driver = {
.probe = pata_platform_probe,
.remove = __devexit_p(pata_platform_remove),
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
},
};
static int __init pata_platform_init(void)
{
return platform_driver_register(&pata_platform_driver);
}
static void __exit pata_platform_exit(void)
{
platform_driver_unregister(&pata_platform_driver);
}
module_init(pata_platform_init);
module_exit(pata_platform_exit);
module_param(pio_mask, int, 0);
MODULE_AUTHOR("Paul Mundt");
MODULE_DESCRIPTION("low-level driver for platform device ATA");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
MODULE_ALIAS("platform:" DRV_NAME);