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alistair23-linux/drivers/ata/pata_at91.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

359 lines
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/*
* PATA driver for AT91SAM9260 Static Memory Controller
* with CompactFlash interface in True IDE mode
*
* Copyright (C) 2009 Matyukevich Sergey
*
* Based on:
* * generic platform driver by Paul Mundt: drivers/ata/pata_platform.c
* * pata_at32 driver by Kristoffer Nyborg Gregertsen
* * at91_ide driver by Stanislaw Gruszka
*
* 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/init.h>
#include <linux/blkdev.h>
#include <linux/gfp.h>
#include <scsi/scsi_host.h>
#include <linux/ata.h>
#include <linux/clk.h>
#include <linux/libata.h>
#include <linux/platform_device.h>
#include <linux/ata_platform.h>
#include <mach/at91sam9_smc.h>
#include <mach/board.h>
#include <mach/gpio.h>
#define DRV_NAME "pata_at91"
#define DRV_VERSION "0.1"
#define CF_IDE_OFFSET 0x00c00000
#define CF_ALT_IDE_OFFSET 0x00e00000
#define CF_IDE_RES_SIZE 0x08
struct at91_ide_info {
unsigned long mode;
unsigned int cs;
struct clk *mck;
void __iomem *ide_addr;
void __iomem *alt_addr;
};
static const struct ata_timing initial_timing =
{XFER_PIO_0, 70, 290, 240, 600, 165, 150, 600, 0};
static unsigned long calc_mck_cycles(unsigned long ns, unsigned long mck_hz)
{
unsigned long mul;
/*
* cycles = x [nsec] * f [Hz] / 10^9 [ns in sec] =
* x * (f / 1_000_000_000) =
* x * ((f * 65536) / 1_000_000_000) / 65536 =
* x * (((f / 10_000) * 65536) / 100_000) / 65536 =
*/
mul = (mck_hz / 10000) << 16;
mul /= 100000;
return (ns * mul + 65536) >> 16; /* rounding */
}
static void set_smc_mode(struct at91_ide_info *info)
{
at91_sys_write(AT91_SMC_MODE(info->cs), info->mode);
return;
}
static void set_smc_timing(struct device *dev,
struct at91_ide_info *info, const struct ata_timing *ata)
{
unsigned long read_cycle, write_cycle, active, recover;
unsigned long nrd_setup, nrd_pulse, nrd_recover;
unsigned long nwe_setup, nwe_pulse;
unsigned long ncs_write_setup, ncs_write_pulse;
unsigned long ncs_read_setup, ncs_read_pulse;
unsigned long mck_hz;
read_cycle = ata->cyc8b;
nrd_setup = ata->setup;
nrd_pulse = ata->act8b;
nrd_recover = ata->rec8b;
mck_hz = clk_get_rate(info->mck);
read_cycle = calc_mck_cycles(read_cycle, mck_hz);
nrd_setup = calc_mck_cycles(nrd_setup, mck_hz);
nrd_pulse = calc_mck_cycles(nrd_pulse, mck_hz);
nrd_recover = calc_mck_cycles(nrd_recover, mck_hz);
active = nrd_setup + nrd_pulse;
recover = read_cycle - active;
/* Need at least two cycles recovery */
if (recover < 2)
read_cycle = active + 2;
/* (CS0, CS1, DIR, OE) <= (CFCE1, CFCE2, CFRNW, NCSX) timings */
ncs_read_setup = 1;
ncs_read_pulse = read_cycle - 2;
/* Write timings same as read timings */
write_cycle = read_cycle;
nwe_setup = nrd_setup;
nwe_pulse = nrd_pulse;
ncs_write_setup = ncs_read_setup;
ncs_write_pulse = ncs_read_pulse;
dev_dbg(dev, "ATA timings: nrd_setup = %lu nrd_pulse = %lu nrd_cycle = %lu\n",
nrd_setup, nrd_pulse, read_cycle);
dev_dbg(dev, "ATA timings: nwe_setup = %lu nwe_pulse = %lu nwe_cycle = %lu\n",
nwe_setup, nwe_pulse, write_cycle);
dev_dbg(dev, "ATA timings: ncs_read_setup = %lu ncs_read_pulse = %lu\n",
ncs_read_setup, ncs_read_pulse);
dev_dbg(dev, "ATA timings: ncs_write_setup = %lu ncs_write_pulse = %lu\n",
ncs_write_setup, ncs_write_pulse);
at91_sys_write(AT91_SMC_SETUP(info->cs),
AT91_SMC_NWESETUP_(nwe_setup) |
AT91_SMC_NRDSETUP_(nrd_setup) |
AT91_SMC_NCS_WRSETUP_(ncs_write_setup) |
AT91_SMC_NCS_RDSETUP_(ncs_read_setup));
at91_sys_write(AT91_SMC_PULSE(info->cs),
AT91_SMC_NWEPULSE_(nwe_pulse) |
AT91_SMC_NRDPULSE_(nrd_pulse) |
AT91_SMC_NCS_WRPULSE_(ncs_write_pulse) |
AT91_SMC_NCS_RDPULSE_(ncs_read_pulse));
at91_sys_write(AT91_SMC_CYCLE(info->cs),
AT91_SMC_NWECYCLE_(write_cycle) |
AT91_SMC_NRDCYCLE_(read_cycle));
return;
}
static void pata_at91_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
struct at91_ide_info *info = ap->host->private_data;
struct ata_timing timing;
int ret;
/* Compute ATA timing and set it to SMC */
ret = ata_timing_compute(adev, adev->pio_mode, &timing, 1000, 0);
if (ret) {
dev_warn(ap->dev, "Failed to compute ATA timing %d, "
"set PIO_0 timing\n", ret);
set_smc_timing(ap->dev, info, &initial_timing);
} else {
set_smc_timing(ap->dev, info, &timing);
}
/* Setup SMC mode */
set_smc_mode(info);
return;
}
static unsigned int pata_at91_data_xfer_noirq(struct ata_device *dev,
unsigned char *buf, unsigned int buflen, int rw)
{
struct at91_ide_info *info = dev->link->ap->host->private_data;
unsigned int consumed;
unsigned long flags;
unsigned int mode;
local_irq_save(flags);
mode = at91_sys_read(AT91_SMC_MODE(info->cs));
/* set 16bit mode before writing data */
at91_sys_write(AT91_SMC_MODE(info->cs),
(mode & ~AT91_SMC_DBW) | AT91_SMC_DBW_16);
consumed = ata_sff_data_xfer(dev, buf, buflen, rw);
/* restore 8bit mode after data is written */
at91_sys_write(AT91_SMC_MODE(info->cs),
(mode & ~AT91_SMC_DBW) | AT91_SMC_DBW_8);
local_irq_restore(flags);
return consumed;
}
static struct scsi_host_template pata_at91_sht = {
ATA_PIO_SHT(DRV_NAME),
};
static struct ata_port_operations pata_at91_port_ops = {
.inherits = &ata_sff_port_ops,
.sff_data_xfer = pata_at91_data_xfer_noirq,
.set_piomode = pata_at91_set_piomode,
.cable_detect = ata_cable_40wire,
};
static int __devinit pata_at91_probe(struct platform_device *pdev)
{
struct at91_cf_data *board = pdev->dev.platform_data;
struct device *dev = &pdev->dev;
struct at91_ide_info *info;
struct resource *mem_res;
struct ata_host *host;
struct ata_port *ap;
int irq_flags = 0;
int irq = 0;
int ret;
/* get platform resources: IO/CTL memories and irq/rst pins */
if (pdev->num_resources != 1) {
dev_err(&pdev->dev, "invalid number of resources\n");
return -EINVAL;
}
mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!mem_res) {
dev_err(dev, "failed to get mem resource\n");
return -EINVAL;
}
irq = board->irq_pin;
/* init ata host */
host = ata_host_alloc(dev, 1);
if (!host)
return -ENOMEM;
ap = host->ports[0];
ap->ops = &pata_at91_port_ops;
ap->flags |= ATA_FLAG_SLAVE_POSS;
ap->pio_mask = ATA_PIO4;
if (!irq) {
ap->flags |= ATA_FLAG_PIO_POLLING;
ata_port_desc(ap, "no IRQ, using PIO polling");
}
info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
if (!info) {
dev_err(dev, "failed to allocate memory for private data\n");
return -ENOMEM;
}
info->mck = clk_get(NULL, "mck");
if (IS_ERR(info->mck)) {
dev_err(dev, "failed to get access to mck clock\n");
return -ENODEV;
}
info->cs = board->chipselect;
info->mode = AT91_SMC_READMODE | AT91_SMC_WRITEMODE |
AT91_SMC_EXNWMODE_READY | AT91_SMC_BAT_SELECT |
AT91_SMC_DBW_8 | AT91_SMC_TDF_(0);
info->ide_addr = devm_ioremap(dev,
mem_res->start + CF_IDE_OFFSET, CF_IDE_RES_SIZE);
if (!info->ide_addr) {
dev_err(dev, "failed to map IO base\n");
ret = -ENOMEM;
goto err_put;
}
info->alt_addr = devm_ioremap(dev,
mem_res->start + CF_ALT_IDE_OFFSET, CF_IDE_RES_SIZE);
if (!info->alt_addr) {
dev_err(dev, "failed to map CTL base\n");
ret = -ENOMEM;
goto err_put;
}
ap->ioaddr.cmd_addr = info->ide_addr;
ap->ioaddr.ctl_addr = info->alt_addr + 0x06;
ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
ata_sff_std_ports(&ap->ioaddr);
ata_port_desc(ap, "mmio cmd 0x%llx ctl 0x%llx",
(unsigned long long)mem_res->start + CF_IDE_OFFSET,
(unsigned long long)mem_res->start + CF_ALT_IDE_OFFSET);
host->private_data = info;
return ata_host_activate(host, irq ? gpio_to_irq(irq) : 0,
irq ? ata_sff_interrupt : NULL,
irq_flags, &pata_at91_sht);
err_put:
clk_put(info->mck);
return ret;
}
static int __devexit pata_at91_remove(struct platform_device *pdev)
{
struct ata_host *host = dev_get_drvdata(&pdev->dev);
struct at91_ide_info *info;
if (!host)
return 0;
info = host->private_data;
ata_host_detach(host);
if (!info)
return 0;
clk_put(info->mck);
return 0;
}
static struct platform_driver pata_at91_driver = {
.probe = pata_at91_probe,
.remove = __devexit_p(pata_at91_remove),
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
},
};
static int __init pata_at91_init(void)
{
return platform_driver_register(&pata_at91_driver);
}
static void __exit pata_at91_exit(void)
{
platform_driver_unregister(&pata_at91_driver);
}
module_init(pata_at91_init);
module_exit(pata_at91_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Driver for CF in True IDE mode on AT91SAM9260 SoC");
MODULE_AUTHOR("Matyukevich Sergey");
MODULE_VERSION(DRV_VERSION);
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