linux-sg2042/drivers/ata/pata_rb532_cf.c

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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 = {
libata: implement and use ops inheritance 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>
2008-03-25 11:22:49 +08:00
.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);