mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-06 02:50:43 +00:00
![Tejun Heo](/assets/img/avatar_default.png)
libata lets low level drivers build ata_port_operations table and register it with libata core layer. This allows low level drivers high level of flexibility but also burdens them with lots of boilerplate entries. This becomes worse for drivers which support related similar controllers which differ slightly. They share most of the operations except for a few. However, the driver still needs to list all operations for each variant. This results in large number of duplicate entries, which is not only inefficient but also error-prone as it becomes very difficult to tell what the actual differences are. This duplicate boilerplates all over the low level drivers also make updating the core layer exteremely difficult and error-prone. When compounded with multi-branched development model, it ends up accumulating inconsistencies over time. Some of those inconsistencies cause immediate problems and fixed. Others just remain there dormant making maintenance increasingly difficult. To rectify the problem, this patch implements ata_port_operations inheritance. To allow LLDs to easily re-use their own ops tables overriding only specific methods, this patch implements poor man's class inheritance. An ops table has ->inherits field which can be set to any ops table as long as it doesn't create a loop. When the host is started, the inheritance chain is followed and any operation which isn't specified is taken from the nearest ancestor which has it specified. This operation is called finalization and done only once per an ops table and the LLD doesn't have to do anything special about it other than making the ops table non-const such that libata can update it. libata provides four base ops tables lower drivers can inherit from - base, sata, pmp, sff and bmdma. To avoid overriding these ops accidentaly, these ops are declared const and LLDs should always inherit these instead of using them directly. After finalization, all the ops table are identical before and after the patch except for setting .irq_handler to ata_interrupt in drivers which didn't use to. The .irq_handler doesn't have any actual effect and the field will soon be removed by later patch. * sata_sx4 is still using old style EH and currently doesn't take advantage of ops inheritance. Signed-off-by: Tejun Heo <htejun@gmail.com>
226 lines
5.8 KiB
C
226 lines
5.8 KiB
C
/*
|
|
* 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.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
*/
|
|
|
|
#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_link_for_each_dev(dev, link) {
|
|
if (ata_dev_enabled(dev)) {
|
|
ata_dev_printk(dev, KERN_INFO, "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_device *dev,
|
|
unsigned char *buf, unsigned int buflen, int rw)
|
|
{
|
|
unsigned int i;
|
|
unsigned int words = buflen >> 1;
|
|
u16 *buf16 = (u16 *) buf;
|
|
struct ata_port *ap = dev->link->ap;
|
|
void __iomem *mmio = ap->ioaddr.data_addr;
|
|
struct ixp4xx_pata_data *data = ap->host->dev->platform_data;
|
|
|
|
/* 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,
|
|
.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_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 __devinit int ixp4xx_pata_probe(struct platform_device *pdev)
|
|
{
|
|
unsigned int irq;
|
|
struct resource *cs0, *cs1;
|
|
struct ata_host *host;
|
|
struct ata_port *ap;
|
|
struct ixp4xx_pata_data *data = pdev->dev.platform_data;
|
|
|
|
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 */
|
|
pdev->dev.coherent_dma_mask = DMA_32BIT_MASK;
|
|
|
|
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)
|
|
set_irq_type(irq, IRQT_RISING);
|
|
|
|
/* 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 = 0x1f; /* PIO4 */
|
|
ap->flags |= ATA_FLAG_MMIO | ATA_FLAG_NO_LEGACY | ATA_FLAG_NO_ATAPI;
|
|
|
|
ixp4xx_setup_port(ap, data, cs0->start, cs1->start);
|
|
|
|
dev_printk(KERN_INFO, &pdev->dev, "version " DRV_VERSION "\n");
|
|
|
|
/* activate host */
|
|
return ata_host_activate(host, irq, ata_interrupt, 0, &ixp4xx_sht);
|
|
}
|
|
|
|
static __devexit int ixp4xx_pata_remove(struct platform_device *dev)
|
|
{
|
|
struct ata_host *host = platform_get_drvdata(dev);
|
|
|
|
ata_host_detach(host);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver ixp4xx_pata_platform_driver = {
|
|
.driver = {
|
|
.name = DRV_NAME,
|
|
.owner = THIS_MODULE,
|
|
},
|
|
.probe = ixp4xx_pata_probe,
|
|
.remove = __devexit_p(ixp4xx_pata_remove),
|
|
};
|
|
|
|
static int __init ixp4xx_pata_init(void)
|
|
{
|
|
return platform_driver_register(&ixp4xx_pata_platform_driver);
|
|
}
|
|
|
|
static void __exit ixp4xx_pata_exit(void)
|
|
{
|
|
platform_driver_unregister(&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_init(ixp4xx_pata_init);
|
|
module_exit(ixp4xx_pata_exit);
|