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kernel / pub / scm / linux / kernel / git / tglx / history / refs/tags/v2.6.11.5 / . / drivers / ide / cris / ide-v10.c
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/* $Id: ide.c,v 1.4 2004/10/12 07:55:48 starvik Exp $
*
* Etrax specific IDE functions, like init and PIO-mode setting etc.
* Almost the entire ide.c is used for the rest of the Etrax ATA driver.
* Copyright (c) 2000-2004 Axis Communications AB
*
* Authors: Bjorn Wesen (initial version)
* Mikael Starvik (pio setup stuff, Linux 2.6 port)
*/
/* Regarding DMA:
*
* There are two forms of DMA - "DMA handshaking" between the interface and the drive,
* and DMA between the memory and the interface. We can ALWAYS use the latter, since it's
* something built-in in the Etrax. However only some drives support the DMA-mode handshaking
* on the ATA-bus. The normal PC driver and Triton interface disables memory-if DMA when the
* device can't do DMA handshaking for some stupid reason. We don't need to do that.
*/
#undef REALLY_SLOW_IO /* most systems can safely undef this */
#include <linux/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/blkdev.h>
#include <linux/hdreg.h>
#include <linux/ide.h>
#include <linux/init.h>
#include <linux/scatterlist.h>
#include <asm/io.h>
#include <asm/arch/svinto.h>
#include <asm/dma.h>
/* number of Etrax DMA descriptors */
#define MAX_DMA_DESCRS 64
/* number of times to retry busy-flags when reading/writing IDE-registers
* this can't be too high because a hung harddisk might cause the watchdog
* to trigger (sometimes INB and OUTB are called with irq's disabled)
*/
#define IDE_REGISTER_TIMEOUT 300
static int e100_read_command = 0;
#define LOWDB(x)
#define D(x)
static int e100_ide_build_dmatable (ide_drive_t *drive);
static ide_startstop_t etrax_dma_intr (ide_drive_t *drive);
void
etrax100_ide_outw(unsigned short data, unsigned long reg) {
int timeleft;
LOWDB(printk("ow: data 0x%x, reg 0x%x\n", data, reg));
/* note the lack of handling any timeouts. we stop waiting, but we don't
* really notify anybody.
*/
timeleft = IDE_REGISTER_TIMEOUT;
/* wait for busy flag */
while(timeleft && (*R_ATA_STATUS_DATA & IO_MASK(R_ATA_STATUS_DATA, busy)))
timeleft--;
/*
* Fall through at a timeout, so the ongoing command will be
* aborted by the write below, which is expected to be a dummy
* command to the command register. This happens when a faulty
* drive times out on a command. See comment on timeout in
* INB.
*/
if(!timeleft)
printk("ATA timeout reg 0x%lx := 0x%x\n", reg, data);
*R_ATA_CTRL_DATA = reg | data; /* write data to the drive's register */
timeleft = IDE_REGISTER_TIMEOUT;
/* wait for transmitter ready */
while(timeleft && !(*R_ATA_STATUS_DATA &
IO_MASK(R_ATA_STATUS_DATA, tr_rdy)))
timeleft--;
}
void
etrax100_ide_outb(unsigned char data, unsigned long reg)
{
etrax100_ide_outw(data, reg);
}
void
etrax100_ide_outbsync(ide_drive_t *drive, u8 addr, unsigned long port)
{
etrax100_ide_outw(addr, port);
}
unsigned short
etrax100_ide_inw(unsigned long reg) {
int status;
int timeleft;
timeleft = IDE_REGISTER_TIMEOUT;
/* wait for busy flag */
while(timeleft && (*R_ATA_STATUS_DATA & IO_MASK(R_ATA_STATUS_DATA, busy)))
timeleft--;
if(!timeleft) {
/*
* If we're asked to read the status register, like for
* example when a command does not complete for an
* extended time, but the ATA interface is stuck in a
* busy state at the *ETRAX* ATA interface level (as has
* happened repeatedly with at least one bad disk), then
* the best thing to do is to pretend that we read
* "busy" in the status register, so the IDE driver will
* time-out, abort the ongoing command and perform a
* reset sequence. Note that the subsequent OUT_BYTE
* call will also timeout on busy, but as long as the
* write is still performed, everything will be fine.
*/
if ((reg & IO_MASK (R_ATA_CTRL_DATA, addr))
== IO_FIELD (R_ATA_CTRL_DATA, addr, IDE_STATUS_OFFSET))
return BUSY_STAT;
else
/* For other rare cases we assume 0 is good enough. */
return 0;
}
*R_ATA_CTRL_DATA = reg | IO_STATE(R_ATA_CTRL_DATA, rw, read); /* read data */
timeleft = IDE_REGISTER_TIMEOUT;
/* wait for available */
while(timeleft && !((status = *R_ATA_STATUS_DATA) &
IO_MASK(R_ATA_STATUS_DATA, dav)))
timeleft--;
if(!timeleft)
return 0;
LOWDB(printk("inb: 0x%x from reg 0x%x\n", status & 0xff, reg));
return (unsigned short)status;
}
unsigned char
etrax100_ide_inb(unsigned long reg)
{
return (unsigned char)etrax100_ide_inw(reg);
}
/* PIO timing (in R_ATA_CONFIG)
*
* _____________________________
* ADDRESS : ________/
*
* _______________
* DIOR : ____________/ \__________
*
* _______________
* DATA : XXXXXXXXXXXXXXXX_______________XXXXXXXX
*
*
* DIOR is unbuffered while address and data is buffered.
* This creates two problems:
* 1. The DIOR pulse is to early (because it is unbuffered)
* 2. The rise time of DIOR is long
*
* There are at least three different plausible solutions
* 1. Use a pad capable of larger currents in Etrax
* 2. Use an external buffer
* 3. Make the strobe pulse longer
*
* Some of the strobe timings below are modified to compensate
* for this. This implies a slight performance decrease.
*
* THIS SHOULD NEVER BE CHANGED!
*
* TODO: Is this true for the latest LX boards still ?
*/
#define ATA_DMA2_STROBE 4
#define ATA_DMA2_HOLD 0
#define ATA_DMA1_STROBE 4
#define ATA_DMA1_HOLD 1
#define ATA_DMA0_STROBE 12
#define ATA_DMA0_HOLD 9
#define ATA_PIO4_SETUP 1
#define ATA_PIO4_STROBE 5
#define ATA_PIO4_HOLD 0
#define ATA_PIO3_SETUP 1
#define ATA_PIO3_STROBE 5
#define ATA_PIO3_HOLD 1
#define ATA_PIO2_SETUP 1
#define ATA_PIO2_STROBE 6
#define ATA_PIO2_HOLD 2
#define ATA_PIO1_SETUP 2
#define ATA_PIO1_STROBE 11
#define ATA_PIO1_HOLD 4
#define ATA_PIO0_SETUP 4
#define ATA_PIO0_STROBE 19
#define ATA_PIO0_HOLD 4
static int e100_dma_check (ide_drive_t *drive);
static void e100_dma_start(ide_drive_t *drive);
static int e100_dma_end (ide_drive_t *drive);
static void e100_ide_input_data (ide_drive_t *drive, void *, unsigned int);
static void e100_ide_output_data (ide_drive_t *drive, void *, unsigned int);
static void e100_atapi_input_bytes(ide_drive_t *drive, void *, unsigned int);
static void e100_atapi_output_bytes(ide_drive_t *drive, void *, unsigned int);
static int e100_dma_off (ide_drive_t *drive);
/*
* good_dma_drives() lists the model names (from "hdparm -i")
* of drives which do not support mword2 DMA but which are
* known to work fine with this interface under Linux.
*/
const char *good_dma_drives[] = {"Micropolis 2112A",
"CONNER CTMA 4000",
"CONNER CTT8000-A",
NULL};
static void tune_e100_ide(ide_drive_t *drive, byte pio)
{
pio = 4;
/* pio = ide_get_best_pio_mode(drive, pio, 4, NULL); */
/* set pio mode! */
switch(pio) {
case 0:
*R_ATA_CONFIG = ( IO_FIELD( R_ATA_CONFIG, enable, 1 ) |
IO_FIELD( R_ATA_CONFIG, dma_strobe, ATA_DMA2_STROBE ) |
IO_FIELD( R_ATA_CONFIG, dma_hold, ATA_DMA2_HOLD ) |
IO_FIELD( R_ATA_CONFIG, pio_setup, ATA_PIO0_SETUP ) |
IO_FIELD( R_ATA_CONFIG, pio_strobe, ATA_PIO0_STROBE ) |
IO_FIELD( R_ATA_CONFIG, pio_hold, ATA_PIO0_HOLD ) );
break;
case 1:
*R_ATA_CONFIG = ( IO_FIELD( R_ATA_CONFIG, enable, 1 ) |
IO_FIELD( R_ATA_CONFIG, dma_strobe, ATA_DMA2_STROBE ) |
IO_FIELD( R_ATA_CONFIG, dma_hold, ATA_DMA2_HOLD ) |
IO_FIELD( R_ATA_CONFIG, pio_setup, ATA_PIO1_SETUP ) |
IO_FIELD( R_ATA_CONFIG, pio_strobe, ATA_PIO1_STROBE ) |
IO_FIELD( R_ATA_CONFIG, pio_hold, ATA_PIO1_HOLD ) );
break;
case 2:
*R_ATA_CONFIG = ( IO_FIELD( R_ATA_CONFIG, enable, 1 ) |
IO_FIELD( R_ATA_CONFIG, dma_strobe, ATA_DMA2_STROBE ) |
IO_FIELD( R_ATA_CONFIG, dma_hold, ATA_DMA2_HOLD ) |
IO_FIELD( R_ATA_CONFIG, pio_setup, ATA_PIO2_SETUP ) |
IO_FIELD( R_ATA_CONFIG, pio_strobe, ATA_PIO2_STROBE ) |
IO_FIELD( R_ATA_CONFIG, pio_hold, ATA_PIO2_HOLD ) );
break;
case 3:
*R_ATA_CONFIG = ( IO_FIELD( R_ATA_CONFIG, enable, 1 ) |
IO_FIELD( R_ATA_CONFIG, dma_strobe, ATA_DMA2_STROBE ) |
IO_FIELD( R_ATA_CONFIG, dma_hold, ATA_DMA2_HOLD ) |
IO_FIELD( R_ATA_CONFIG, pio_setup, ATA_PIO3_SETUP ) |
IO_FIELD( R_ATA_CONFIG, pio_strobe, ATA_PIO3_STROBE ) |
IO_FIELD( R_ATA_CONFIG, pio_hold, ATA_PIO3_HOLD ) );
break;
case 4:
*R_ATA_CONFIG = ( IO_FIELD( R_ATA_CONFIG, enable, 1 ) |
IO_FIELD( R_ATA_CONFIG, dma_strobe, ATA_DMA2_STROBE ) |
IO_FIELD( R_ATA_CONFIG, dma_hold, ATA_DMA2_HOLD ) |
IO_FIELD( R_ATA_CONFIG, pio_setup, ATA_PIO4_SETUP ) |
IO_FIELD( R_ATA_CONFIG, pio_strobe, ATA_PIO4_STROBE ) |
IO_FIELD( R_ATA_CONFIG, pio_hold, ATA_PIO4_HOLD ) );
break;
}
}
static int e100_dma_setup(ide_drive_t *drive)
{
struct request *rq = drive->hwif->hwgroup->rq;
if (rq_data_dir(rq)) {
e100_read_command = 0;
RESET_DMA(ATA_TX_DMA_NBR); /* sometimes the DMA channel get stuck so we need to do this */
WAIT_DMA(ATA_TX_DMA_NBR);
} else {
e100_read_command = 1;
RESET_DMA(ATA_RX_DMA_NBR); /* sometimes the DMA channel get stuck so we need to do this */
WAIT_DMA(ATA_RX_DMA_NBR);
}
/* set up the Etrax DMA descriptors */
if (e100_ide_build_dmatable(drive)) {
ide_map_sg(drive, rq);
return 1;
}
return 0;
}
static void e100_dma_exec_cmd(ide_drive_t *drive, u8 command)
{
/* set the irq handler which will finish the request when DMA is done */
ide_set_handler(drive, &etrax_dma_intr, WAIT_CMD, NULL);
/* issue cmd to drive */
etrax100_ide_outb(command, IDE_COMMAND_REG);
}
void __init
init_e100_ide (void)
{
volatile unsigned int dummy;
int h;
printk("ide: ETRAX 100LX built-in ATA DMA controller\n");
/* first fill in some stuff in the ide_hwifs fields */
for(h = 0; h < MAX_HWIFS; h++) {
ide_hwif_t *hwif = &ide_hwifs[h];
hwif->mmio = 2;
hwif->chipset = ide_etrax100;
hwif->tuneproc = &tune_e100_ide;
hwif->ata_input_data = &e100_ide_input_data;
hwif->ata_output_data = &e100_ide_output_data;
hwif->atapi_input_bytes = &e100_atapi_input_bytes;
hwif->atapi_output_bytes = &e100_atapi_output_bytes;
hwif->ide_dma_check = &e100_dma_check;
hwif->ide_dma_end = &e100_dma_end;
hwif->dma_setup = &e100_dma_setup;
hwif->dma_exec_cmd = &e100_dma_exec_cmd;
hwif->dma_start = &e100_dma_start;
hwif->OUTB = &etrax100_ide_outb;
hwif->OUTW = &etrax100_ide_outw;
hwif->OUTBSYNC = &etrax100_ide_outbsync;
hwif->INB = &etrax100_ide_inb;
hwif->INW = &etrax100_ide_inw;
hwif->ide_dma_off_quietly = &e100_dma_off;
}
/* actually reset and configure the etrax100 ide/ata interface */
*R_ATA_CTRL_DATA = 0;
*R_ATA_TRANSFER_CNT = 0;
*R_ATA_CONFIG = 0;
genconfig_shadow = (genconfig_shadow &
~IO_MASK(R_GEN_CONFIG, dma2) &
~IO_MASK(R_GEN_CONFIG, dma3) &
~IO_MASK(R_GEN_CONFIG, ata)) |
( IO_STATE( R_GEN_CONFIG, dma3, ata ) |
IO_STATE( R_GEN_CONFIG, dma2, ata ) |
IO_STATE( R_GEN_CONFIG, ata, select ) );
*R_GEN_CONFIG = genconfig_shadow;
/* pull the chosen /reset-line low */
#ifdef CONFIG_ETRAX_IDE_G27_RESET
REG_SHADOW_SET(R_PORT_G_DATA, port_g_data_shadow, 27, 0);
#endif
#ifdef CONFIG_ETRAX_IDE_CSE1_16_RESET
REG_SHADOW_SET(port_cse1_addr, port_cse1_shadow, 16, 0);
#endif
#ifdef CONFIG_ETRAX_IDE_CSP0_8_RESET
REG_SHADOW_SET(port_csp0_addr, port_csp0_shadow, 8, 0);
#endif
#ifdef CONFIG_ETRAX_IDE_PB7_RESET
port_pb_dir_shadow = port_pb_dir_shadow |
IO_STATE(R_PORT_PB_DIR, dir7, output);
*R_PORT_PB_DIR = port_pb_dir_shadow;
REG_SHADOW_SET(R_PORT_PB_DATA, port_pb_data_shadow, 7, 1);
#endif
/* wait some */
udelay(25);
/* de-assert bus-reset */
#ifdef CONFIG_ETRAX_IDE_CSE1_16_RESET
REG_SHADOW_SET(port_cse1_addr, port_cse1_shadow, 16, 1);
#endif
#ifdef CONFIG_ETRAX_IDE_CSP0_8_RESET
REG_SHADOW_SET(port_csp0_addr, port_csp0_shadow, 8, 1);
#endif
#ifdef CONFIG_ETRAX_IDE_G27_RESET
REG_SHADOW_SET(R_PORT_G_DATA, port_g_data_shadow, 27, 1);
#endif
/* make a dummy read to set the ata controller in a proper state */
dummy = *R_ATA_STATUS_DATA;
*R_ATA_CONFIG = ( IO_FIELD( R_ATA_CONFIG, enable, 1 ) |
IO_FIELD( R_ATA_CONFIG, dma_strobe, ATA_DMA2_STROBE ) |
IO_FIELD( R_ATA_CONFIG, dma_hold, ATA_DMA2_HOLD ) |
IO_FIELD( R_ATA_CONFIG, pio_setup, ATA_PIO4_SETUP ) |
IO_FIELD( R_ATA_CONFIG, pio_strobe, ATA_PIO4_STROBE ) |
IO_FIELD( R_ATA_CONFIG, pio_hold, ATA_PIO4_HOLD ) );
*R_ATA_CTRL_DATA = ( IO_STATE( R_ATA_CTRL_DATA, rw, read) |
IO_FIELD( R_ATA_CTRL_DATA, addr, 1 ) );
while(*R_ATA_STATUS_DATA & IO_MASK(R_ATA_STATUS_DATA, busy)); /* wait for busy flag*/
*R_IRQ_MASK0_SET = ( IO_STATE( R_IRQ_MASK0_SET, ata_irq0, set ) |
IO_STATE( R_IRQ_MASK0_SET, ata_irq1, set ) |
IO_STATE( R_IRQ_MASK0_SET, ata_irq2, set ) |
IO_STATE( R_IRQ_MASK0_SET, ata_irq3, set ) );
printk("ide: waiting %d seconds for drives to regain consciousness\n",
CONFIG_ETRAX_IDE_DELAY);
h = jiffies + (CONFIG_ETRAX_IDE_DELAY * HZ);
while(time_before(jiffies, h)) /* nothing */ ;
/* reset the dma channels we will use */
RESET_DMA(ATA_TX_DMA_NBR);
RESET_DMA(ATA_RX_DMA_NBR);
WAIT_DMA(ATA_TX_DMA_NBR);
WAIT_DMA(ATA_RX_DMA_NBR);
}
static int e100_dma_off (ide_drive_t *drive)
{
return 0;
}
static etrax_dma_descr mydescr;
/*
* The following routines are mainly used by the ATAPI drivers.
*
* These routines will round up any request for an odd number of bytes,
* so if an odd bytecount is specified, be sure that there's at least one
* extra byte allocated for the buffer.
*/
static void
e100_atapi_input_bytes (ide_drive_t *drive, void *buffer, unsigned int bytecount)
{
unsigned long data_reg = IDE_DATA_REG;
D(printk("atapi_input_bytes, dreg 0x%x, buffer 0x%x, count %d\n",
data_reg, buffer, bytecount));
if(bytecount & 1) {
printk("warning, odd bytecount in cdrom_in_bytes = %d.\n", bytecount);
bytecount++; /* to round off */
}
/* make sure the DMA channel is available */
RESET_DMA(ATA_RX_DMA_NBR);
WAIT_DMA(ATA_RX_DMA_NBR);
/* setup DMA descriptor */
mydescr.sw_len = bytecount;
mydescr.ctrl = d_eol;
mydescr.buf = virt_to_phys(buffer);
/* start the dma channel */
*R_DMA_CH3_FIRST = virt_to_phys(&mydescr);
*R_DMA_CH3_CMD = IO_STATE(R_DMA_CH3_CMD, cmd, start);
/* initiate a multi word dma read using PIO handshaking */
*R_ATA_TRANSFER_CNT = IO_FIELD(R_ATA_TRANSFER_CNT, count, bytecount >> 1);
*R_ATA_CTRL_DATA = data_reg |
IO_STATE(R_ATA_CTRL_DATA, rw, read) |
IO_STATE(R_ATA_CTRL_DATA, src_dst, dma) |
IO_STATE(R_ATA_CTRL_DATA, handsh, pio) |
IO_STATE(R_ATA_CTRL_DATA, multi, on) |
IO_STATE(R_ATA_CTRL_DATA, dma_size, word);
/* wait for completion */
LED_DISK_READ(1);
WAIT_DMA(ATA_RX_DMA_NBR);
LED_DISK_READ(0);
#if 0
/* old polled transfer code
* this should be moved into a new function that can do polled
* transfers if DMA is not available
*/
/* initiate a multi word read */
*R_ATA_TRANSFER_CNT = wcount << 1;
*R_ATA_CTRL_DATA = data_reg |
IO_STATE(R_ATA_CTRL_DATA, rw, read) |
IO_STATE(R_ATA_CTRL_DATA, src_dst, register) |
IO_STATE(R_ATA_CTRL_DATA, handsh, pio) |
IO_STATE(R_ATA_CTRL_DATA, multi, on) |
IO_STATE(R_ATA_CTRL_DATA, dma_size, word);
/* svinto has a latency until the busy bit actually is set */
nop(); nop();
nop(); nop();
nop(); nop();
nop(); nop();
nop(); nop();
/* unit should be busy during multi transfer */
while((status = *R_ATA_STATUS_DATA) & IO_MASK(R_ATA_STATUS_DATA, busy)) {
while(!(status & IO_MASK(R_ATA_STATUS_DATA, dav)))
status = *R_ATA_STATUS_DATA;
*ptr++ = (unsigned short)(status & 0xffff);
}
#endif
}
static void
e100_atapi_output_bytes (ide_drive_t *drive, void *buffer, unsigned int bytecount)
{
unsigned long data_reg = IDE_DATA_REG;
D(printk("atapi_output_bytes, dreg 0x%x, buffer 0x%x, count %d\n",
data_reg, buffer, bytecount));
if(bytecount & 1) {
printk("odd bytecount %d in atapi_out_bytes!\n", bytecount);
bytecount++;
}
/* make sure the DMA channel is available */
RESET_DMA(ATA_TX_DMA_NBR);
WAIT_DMA(ATA_TX_DMA_NBR);
/* setup DMA descriptor */
mydescr.sw_len = bytecount;
mydescr.ctrl = d_eol;
mydescr.buf = virt_to_phys(buffer);
/* start the dma channel */
*R_DMA_CH2_FIRST = virt_to_phys(&mydescr);
*R_DMA_CH2_CMD = IO_STATE(R_DMA_CH2_CMD, cmd, start);
/* initiate a multi word dma write using PIO handshaking */
*R_ATA_TRANSFER_CNT = IO_FIELD(R_ATA_TRANSFER_CNT, count, bytecount >> 1);
*R_ATA_CTRL_DATA = data_reg |
IO_STATE(R_ATA_CTRL_DATA, rw, write) |
IO_STATE(R_ATA_CTRL_DATA, src_dst, dma) |
IO_STATE(R_ATA_CTRL_DATA, handsh, pio) |
IO_STATE(R_ATA_CTRL_DATA, multi, on) |
IO_STATE(R_ATA_CTRL_DATA, dma_size, word);
/* wait for completion */
LED_DISK_WRITE(1);
WAIT_DMA(ATA_TX_DMA_NBR);
LED_DISK_WRITE(0);
#if 0
/* old polled write code - see comment in input_bytes */
/* wait for busy flag */
while(*R_ATA_STATUS_DATA & IO_MASK(R_ATA_STATUS_DATA, busy));
/* initiate a multi word write */
*R_ATA_TRANSFER_CNT = bytecount >> 1;
ctrl = data_reg |
IO_STATE(R_ATA_CTRL_DATA, rw, write) |
IO_STATE(R_ATA_CTRL_DATA, src_dst, register) |
IO_STATE(R_ATA_CTRL_DATA, handsh, pio) |
IO_STATE(R_ATA_CTRL_DATA, multi, on) |
IO_STATE(R_ATA_CTRL_DATA, dma_size, word);
LED_DISK_WRITE(1);
/* Etrax will set busy = 1 until the multi pio transfer has finished
* and tr_rdy = 1 after each successful word transfer.
* When the last byte has been transferred Etrax will first set tr_tdy = 1
* and then busy = 0 (not in the same cycle). If we read busy before it
* has been set to 0 we will think that we should transfer more bytes
* and then tr_rdy would be 0 forever. This is solved by checking busy
* in the inner loop.
*/
do {
*R_ATA_CTRL_DATA = ctrl | *ptr++;
while(!(*R_ATA_STATUS_DATA & IO_MASK(R_ATA_STATUS_DATA, tr_rdy)) &&
(*R_ATA_STATUS_DATA & IO_MASK(R_ATA_STATUS_DATA, busy)));
} while(*R_ATA_STATUS_DATA & IO_MASK(R_ATA_STATUS_DATA, busy));
LED_DISK_WRITE(0);
#endif
}
/*
* This is used for most PIO data transfers *from* the IDE interface
*/
static void
e100_ide_input_data (ide_drive_t *drive, void *buffer, unsigned int wcount)
{
e100_atapi_input_bytes(drive, buffer, wcount << 2);
}
/*
* This is used for most PIO data transfers *to* the IDE interface
*/
static void
e100_ide_output_data (ide_drive_t *drive, void *buffer, unsigned int wcount)
{
e100_atapi_output_bytes(drive, buffer, wcount << 2);
}
/* we only have one DMA channel on the chip for ATA, so we can keep these statically */
static etrax_dma_descr ata_descrs[MAX_DMA_DESCRS];
static unsigned int ata_tot_size;
/*
* e100_ide_build_dmatable() prepares a dma request.
* Returns 0 if all went okay, returns 1 otherwise.
*/
static int e100_ide_build_dmatable (ide_drive_t *drive)
{
ide_hwif_t *hwif = HWIF(drive);
struct scatterlist* sg;
struct request *rq = HWGROUP(drive)->rq;
unsigned long size, addr;
unsigned int count = 0;
int i = 0;
sg = hwif->sg_table;
ata_tot_size = 0;
ide_map_sg(drive, rq);
i = hwif->sg_nents;
while(i) {
/*
* Determine addr and size of next buffer area. We assume that
* individual virtual buffers are always composed linearly in
* physical memory. For example, we assume that any 8kB buffer
* is always composed of two adjacent physical 4kB pages rather
* than two possibly non-adjacent physical 4kB pages.
*/
/* group sequential buffers into one large buffer */
addr = page_to_phys(sg->page) + sg->offset;
size = sg_dma_len(sg);
while (sg++, --i) {
if ((addr + size) != page_to_phys(sg->page) + sg->offset)
break;
size += sg_dma_len(sg);
}
/* did we run out of descriptors? */
if(count >= MAX_DMA_DESCRS) {
printk("%s: too few DMA descriptors\n", drive->name);
return 1;
}
/* however, this case is more difficult - R_ATA_TRANSFER_CNT cannot be more
than 65536 words per transfer, so in that case we need to either
1) use a DMA interrupt to re-trigger R_ATA_TRANSFER_CNT and continue with
the descriptors, or
2) simply do the request here, and get dma_intr to only ide_end_request on
those blocks that were actually set-up for transfer.
*/
if(ata_tot_size + size > 131072) {
printk("too large total ATA DMA request, %d + %d!\n", ata_tot_size, (int)size);
return 1;
}
/* If size > 65536 it has to be splitted into new descriptors. Since we don't handle
size > 131072 only one split is necessary */
if(size > 65536) {
/* ok we want to do IO at addr, size bytes. set up a new descriptor entry */
ata_descrs[count].sw_len = 0; /* 0 means 65536, this is a 16-bit field */
ata_descrs[count].ctrl = 0;
ata_descrs[count].buf = addr;
ata_descrs[count].next = virt_to_phys(&ata_descrs[count + 1]);
count++;
ata_tot_size += 65536;
/* size and addr should refere to not handled data */
size -= 65536;
addr += 65536;
}
/* ok we want to do IO at addr, size bytes. set up a new descriptor entry */
if(size == 65536) {
ata_descrs[count].sw_len = 0; /* 0 means 65536, this is a 16-bit field */
} else {
ata_descrs[count].sw_len = size;
}
ata_descrs[count].ctrl = 0;
ata_descrs[count].buf = addr;
ata_descrs[count].next = virt_to_phys(&ata_descrs[count + 1]);
count++;
ata_tot_size += size;
}
if (count) {
/* set the end-of-list flag on the last descriptor */
ata_descrs[count - 1].ctrl |= d_eol;
/* return and say all is ok */
return 0;
}
printk("%s: empty DMA table?\n", drive->name);
return 1; /* let the PIO routines handle this weirdness */
}
static int config_drive_for_dma (ide_drive_t *drive)
{
const char **list;
struct hd_driveid *id = drive->id;
if (id && (id->capability & 1)) {
/* Enable DMA on any drive that supports mword2 DMA */
if ((id->field_valid & 2) && (id->dma_mword & 0x404) == 0x404) {
drive->using_dma = 1;
return 0; /* DMA enabled */
}
/* Consult the list of known "good" drives */
list = good_dma_drives;
while (*list) {
if (!strcmp(*list++,id->model)) {
drive->using_dma = 1;
return 0; /* DMA enabled */
}
}
}
return 1; /* DMA not enabled */
}
/*
* etrax_dma_intr() is the handler for disk read/write DMA interrupts
*/
static ide_startstop_t etrax_dma_intr (ide_drive_t *drive)
{
LED_DISK_READ(0);
LED_DISK_WRITE(0);
return ide_dma_intr(drive);
}
/*
* Functions below initiates/aborts DMA read/write operations on a drive.
*
* The caller is assumed to have selected the drive and programmed the drive's
* sector address using CHS or LBA. All that remains is to prepare for DMA
* and then issue the actual read/write DMA/PIO command to the drive.
*
* Returns 0 if all went well.
* Returns 1 if DMA read/write could not be started, in which case
* the caller should revert to PIO for the current request.
*/
static int e100_dma_check(ide_drive_t *drive)
{
return config_drive_for_dma (drive);
}
static int e100_dma_end(ide_drive_t *drive)
{
/* TODO: check if something went wrong with the DMA */
return 0;
}
static void e100_dma_start(ide_drive_t *drive)
{
if (e100_read_command) {
/* begin DMA */
/* need to do this before RX DMA due to a chip bug
* it is enough to just flush the part of the cache that
* corresponds to the buffers we start, but since HD transfers
* usually are more than 8 kB, it is easier to optimize for the
* normal case and just flush the entire cache. its the only
* way to be sure! (OB movie quote)
*/
flush_etrax_cache();
*R_DMA_CH3_FIRST = virt_to_phys(ata_descrs);
*R_DMA_CH3_CMD = IO_STATE(R_DMA_CH3_CMD, cmd, start);
/* initiate a multi word dma read using DMA handshaking */
*R_ATA_TRANSFER_CNT =
IO_FIELD(R_ATA_TRANSFER_CNT, count, ata_tot_size >> 1);
*R_ATA_CTRL_DATA =
IO_FIELD(R_ATA_CTRL_DATA, data, IDE_DATA_REG) |
IO_STATE(R_ATA_CTRL_DATA, rw, read) |
IO_STATE(R_ATA_CTRL_DATA, src_dst, dma) |
IO_STATE(R_ATA_CTRL_DATA, handsh, dma) |
IO_STATE(R_ATA_CTRL_DATA, multi, on) |
IO_STATE(R_ATA_CTRL_DATA, dma_size, word);
LED_DISK_READ(1);
D(printk("dma read of %d bytes.\n", ata_tot_size));
} else {
/* writing */
/* begin DMA */
*R_DMA_CH2_FIRST = virt_to_phys(ata_descrs);
*R_DMA_CH2_CMD = IO_STATE(R_DMA_CH2_CMD, cmd, start);
/* initiate a multi word dma write using DMA handshaking */
*R_ATA_TRANSFER_CNT =
IO_FIELD(R_ATA_TRANSFER_CNT, count, ata_tot_size >> 1);
*R_ATA_CTRL_DATA =
IO_FIELD(R_ATA_CTRL_DATA, data, IDE_DATA_REG) |
IO_STATE(R_ATA_CTRL_DATA, rw, write) |
IO_STATE(R_ATA_CTRL_DATA, src_dst, dma) |
IO_STATE(R_ATA_CTRL_DATA, handsh, dma) |
IO_STATE(R_ATA_CTRL_DATA, multi, on) |
IO_STATE(R_ATA_CTRL_DATA, dma_size, word);
LED_DISK_WRITE(1);
D(printk("dma write of %d bytes.\n", ata_tot_size));
}
}