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alistair23-linux/drivers/ata/pata_rb532_cf.c
Alan Cox a57c1bade5 libata-sff: Fix oops reported in kerneloops.org for pnp devices with no ctl 
- Make ata_sff_altstatus private so nobody uses it by mistake
- Drop the 400nS delay from it

Add

ata_sff_irq_status	-	encapsulates the IRQ check logic

This function keeps the existing behaviour for altstatus using devices. I
actually suspect the logic was wrong before the changes but -rc isn't the
time to play with that

ata_sff_sync		-	ensure writes hit the device

Really we want an io* operation for 'is posted' eg ioisposted(ioaddr) so
that we can fix the nasty delay this causes on most systems.

- ata_sff_pause		-	400nS delay

Ensure the command hit the device and delay 400nS

- ata_sff_dma_pause

Ensure the I/O hit the device and enforce an HDMA1:0 transition delay.
Requires altstatus register exists, BUG if not so we don't risk
corruption in MWDMA modes. (UDMA the checksum will save your backside in
theory)

The only other complication then is devices with their own handlers.
rb532 can use dma_pause but scc needs to access its own altstatus
register for internal errata workarounds so directly call the drivers own
altstatus function.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2008-06-04 06:40:41 -04:00

280 lines
6.6 KiB
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/*
* A low-level PATA driver to handle a Compact Flash connected on the
* Mikrotik's RouterBoard 532 board.
*
* Copyright (C) 2007 Gabor Juhos <juhosg at openwrt.org>
* Copyright (C) 2008 Florian Fainelli <florian@openwrt.org>
*
* This file was based on: drivers/ata/pata_ixp4xx_cf.c
* Copyright (C) 2006-07 Tower Technologies
* Author: Alessandro Zummo <a.zummo@towertech.it>
*
* Also was based on the driver for Linux 2.4.xx published by Mikrotik for
* their RouterBoard 1xx and 5xx series devices. The original Mikrotik code
* seems not to have a license.
*
* 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/platform_device.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/libata.h>
#include <scsi/scsi_host.h>
#include <asm/gpio.h>
#define DRV_NAME "pata-rb532-cf"
#define DRV_VERSION "0.1.0"
#define DRV_DESC "PATA driver for RouterBOARD 532 Compact Flash"
#define RB500_CF_MAXPORTS 1
#define RB500_CF_IO_DELAY 400
#define RB500_CF_REG_CMD 0x0800
#define RB500_CF_REG_CTRL 0x080E
#define RB500_CF_REG_DATA 0x0C00
struct rb532_cf_info {
void __iomem *iobase;
unsigned int gpio_line;
int frozen;
unsigned int irq;
};
/* ------------------------------------------------------------------------ */
static inline void rb532_pata_finish_io(struct ata_port *ap)
{
struct ata_host *ah = ap->host;
struct rb532_cf_info *info = ah->private_data;
/* FIXME: Keep previous delay. If this is merely a fence then
ata_sff_sync might be sufficient. */
ata_sff_dma_pause(ap);
ndelay(RB500_CF_IO_DELAY);
set_irq_type(info->irq, IRQ_TYPE_LEVEL_HIGH);
}
static void rb532_pata_exec_command(struct ata_port *ap,
const struct ata_taskfile *tf)
{
writeb(tf->command, ap->ioaddr.command_addr);
rb532_pata_finish_io(ap);
}
static void rb532_pata_data_xfer(struct ata_device *adev, unsigned char *buf,
unsigned int buflen, int write_data)
{
struct ata_port *ap = adev->link->ap;
void __iomem *ioaddr = ap->ioaddr.data_addr;
if (write_data) {
for (; buflen > 0; buflen--, buf++)
writeb(*buf, ioaddr);
} else {
for (; buflen > 0; buflen--, buf++)
*buf = readb(ioaddr);
}
rb532_pata_finish_io(adev->link->ap);
}
static void rb532_pata_freeze(struct ata_port *ap)
{
struct rb532_cf_info *info = ap->host->private_data;
info->frozen = 1;
}
static void rb532_pata_thaw(struct ata_port *ap)
{
struct rb532_cf_info *info = ap->host->private_data;
info->frozen = 0;
}
static irqreturn_t rb532_pata_irq_handler(int irq, void *dev_instance)
{
struct ata_host *ah = dev_instance;
struct rb532_cf_info *info = ah->private_data;
if (gpio_get_value(info->gpio_line)) {
set_irq_type(info->irq, IRQ_TYPE_LEVEL_LOW);
if (!info->frozen)
ata_sff_interrupt(info->irq, dev_instance);
} else {
set_irq_type(info->irq, IRQ_TYPE_LEVEL_HIGH);
}
return IRQ_HANDLED;
}
static struct ata_port_operations rb532_pata_port_ops = {
.inherits = &ata_sff_port_ops,
.sff_exec_command = rb532_pata_exec_command,
.sff_data_xfer = rb532_pata_data_xfer,
.freeze = rb532_pata_freeze,
.thaw = rb532_pata_thaw,
};
/* ------------------------------------------------------------------------ */
static struct scsi_host_template rb532_pata_sht = {
ATA_PIO_SHT(DRV_NAME),
};
/* ------------------------------------------------------------------------ */
static void rb532_pata_setup_ports(struct ata_host *ah)
{
struct rb532_cf_info *info = ah->private_data;
struct ata_port *ap;
ap = ah->ports[0];
ap->ops = &rb532_pata_port_ops;
ap->pio_mask = 0x1f; /* PIO4 */
ap->flags = ATA_FLAG_NO_LEGACY | ATA_FLAG_MMIO;
ap->ioaddr.cmd_addr = info->iobase + RB500_CF_REG_CMD;
ap->ioaddr.ctl_addr = info->iobase + RB500_CF_REG_CTRL;
ap->ioaddr.altstatus_addr = info->iobase + RB500_CF_REG_CTRL;
ata_sff_std_ports(&ap->ioaddr);
ap->ioaddr.data_addr = info->iobase + RB500_CF_REG_DATA;
}
static __devinit int rb532_pata_driver_probe(struct platform_device *pdev)
{
unsigned int irq;
int gpio;
struct resource *res;
struct ata_host *ah;
struct rb532_cf_info *info;
int ret;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "no IOMEM resource found\n");
return -EINVAL;
}
irq = platform_get_irq(pdev, 0);
if (irq <= 0) {
dev_err(&pdev->dev, "no IRQ resource found\n");
return -ENOENT;
}
gpio = irq_to_gpio(irq);
if (gpio < 0) {
dev_err(&pdev->dev, "no GPIO found for irq%d\n", irq);
return -ENOENT;
}
ret = gpio_request(gpio, DRV_NAME);
if (ret) {
dev_err(&pdev->dev, "GPIO request failed\n");
return ret;
}
/* allocate host */
ah = ata_host_alloc(&pdev->dev, RB500_CF_MAXPORTS);
if (!ah)
return -ENOMEM;
platform_set_drvdata(pdev, ah);
info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
ah->private_data = info;
info->gpio_line = gpio;
info->irq = irq;
info->iobase = devm_ioremap_nocache(&pdev->dev, res->start,
res->end - res->start + 1);
if (!info->iobase)
return -ENOMEM;
ret = gpio_direction_input(gpio);
if (ret) {
dev_err(&pdev->dev, "unable to set GPIO direction, err=%d\n",
ret);
goto err_free_gpio;
}
rb532_pata_setup_ports(ah);
ret = ata_host_activate(ah, irq, rb532_pata_irq_handler,
IRQF_TRIGGER_LOW, &rb532_pata_sht);
if (ret)
goto err_free_gpio;
return 0;
err_free_gpio:
gpio_free(gpio);
return ret;
}
static __devexit int rb532_pata_driver_remove(struct platform_device *pdev)
{
struct ata_host *ah = platform_get_drvdata(pdev);
struct rb532_cf_info *info = ah->private_data;
ata_host_detach(ah);
gpio_free(info->gpio_line);
return 0;
}
/* work with hotplug and coldplug */
MODULE_ALIAS("platform:" DRV_NAME);
static struct platform_driver rb532_pata_platform_driver = {
.probe = rb532_pata_driver_probe,
.remove = __devexit_p(rb532_pata_driver_remove),
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
},
};
/* ------------------------------------------------------------------------ */
#define DRV_INFO DRV_DESC " version " DRV_VERSION
static int __init rb532_pata_module_init(void)
{
printk(KERN_INFO DRV_INFO "\n");
return platform_driver_register(&rb532_pata_platform_driver);
}
static void __exit rb532_pata_module_exit(void)
{
platform_driver_unregister(&rb532_pata_platform_driver);
}
MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
MODULE_DESCRIPTION(DRV_DESC);
MODULE_VERSION(DRV_VERSION);
MODULE_LICENSE("GPL");
module_init(rb532_pata_module_init);
module_exit(rb532_pata_module_exit);
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