[PATCH] CRIS IDE driver

  * Added abstraction layer for subarchs.
  * Added v32 support.
  * Renamed driver.

Signed-off-by: Mikael Starvik <starvik@axis.com>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1107 insertions, 0 deletions

diff --git a/drivers/ide/cris/ide-cris.c b/drivers/ide/cris/ide-cris.c
new file mode 100644
index 000000000000..cd15e6260510
--- /dev/null
+++ b/drivers/ide/cris/ide-cris.c
@@ -0,0 +1,1107 @@
+/* $Id: cris-ide-driver.patch,v 1.1 2005/06/29 21:39:07 akpm 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) 2000-2005 Axis Communications AB
+ *
+ * Authors:    Bjorn Wesen        (initial version)
+ *             Mikael Starvik     (crisv32 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 <asm/io.h>
+#include <asm/dma.h>
+
+/* number of 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
+
+#define LOWDB(x)
+#define D(x)
+
+enum /* Transfer types */
+{
+	TYPE_PIO,
+	TYPE_DMA,
+	TYPE_UDMA
+};
+
+/* CRISv32 specifics */
+#ifdef CONFIG_ETRAX_ARCH_V32
+#include <asm/arch/hwregs/ata_defs.h>
+#include <asm/arch/hwregs/dma_defs.h>
+#include <asm/arch/hwregs/dma.h>
+#include <asm/arch/pinmux.h>
+
+#define ATA_UDMA2_CYC    2
+#define ATA_UDMA2_DVS    3
+#define ATA_UDMA1_CYC    2
+#define ATA_UDMA1_DVS    4
+#define ATA_UDMA0_CYC    4
+#define ATA_UDMA0_DVS    6
+#define ATA_DMA2_STROBE  7
+#define ATA_DMA2_HOLD    1
+#define ATA_DMA1_STROBE  8
+#define ATA_DMA1_HOLD    3
+#define ATA_DMA0_STROBE 25
+#define ATA_DMA0_HOLD   19
+#define ATA_PIO4_SETUP   3
+#define ATA_PIO4_STROBE  7
+#define ATA_PIO4_HOLD    1
+#define ATA_PIO3_SETUP   3
+#define ATA_PIO3_STROBE  9
+#define ATA_PIO3_HOLD    3
+#define ATA_PIO2_SETUP   3
+#define ATA_PIO2_STROBE 13
+#define ATA_PIO2_HOLD    5
+#define ATA_PIO1_SETUP   5
+#define ATA_PIO1_STROBE 23
+#define ATA_PIO1_HOLD    9
+#define ATA_PIO0_SETUP   9
+#define ATA_PIO0_STROBE 39
+#define ATA_PIO0_HOLD    9
+
+int
+cris_ide_ack_intr(ide_hwif_t* hwif)
+{
+	reg_ata_rw_ctrl2 ctrl2 = REG_TYPE_CONV(reg_ata_rw_ctrl2,
+	                         int, hwif->io_ports[0]);
+	REG_WR_INT(ata, regi_ata, rw_ack_intr, 1 << ctrl2.sel);
+	return 1;
+}
+
+static inline int
+cris_ide_busy(void)
+{
+	reg_ata_rs_stat_data stat_data;
+	stat_data = REG_RD(ata, regi_ata, rs_stat_data);
+	return stat_data.busy;
+}
+
+static inline int
+cris_ide_ready(void)
+{
+	return !cris_ide_busy();
+}
+
+static inline int
+cris_ide_data_available(unsigned short* data)
+{
+	reg_ata_rs_stat_data stat_data;
+	stat_data = REG_RD(ata, regi_ata, rs_stat_data);
+	*data = stat_data.data;
+	return stat_data.dav;
+}
+
+static void
+cris_ide_write_command(unsigned long command)
+{
+	REG_WR_INT(ata, regi_ata, rw_ctrl2, command); /* write data to the drive's register */
+}
+
+static void
+cris_ide_set_speed(int type, int setup, int strobe, int hold)
+{
+	reg_ata_rw_ctrl0 ctrl0 = REG_RD(ata, regi_ata, rw_ctrl0);
+	reg_ata_rw_ctrl1 ctrl1 = REG_RD(ata, regi_ata, rw_ctrl1);
+
+	if (type == TYPE_PIO) {
+		ctrl0.pio_setup = setup;
+		ctrl0.pio_strb = strobe;
+		ctrl0.pio_hold = hold;
+	} else if (type == TYPE_DMA) {
+		ctrl0.dma_strb = strobe;
+		ctrl0.dma_hold = hold;
+	} else if (type == TYPE_UDMA) {
+		ctrl1.udma_tcyc = setup;
+		ctrl1.udma_tdvs = strobe;
+	}
+	REG_WR(ata, regi_ata, rw_ctrl0, ctrl0);
+	REG_WR(ata, regi_ata, rw_ctrl1, ctrl1);
+}
+
+static unsigned long
+cris_ide_base_address(int bus)
+{
+	reg_ata_rw_ctrl2 ctrl2 = {0};
+	ctrl2.sel = bus;
+	return REG_TYPE_CONV(int, reg_ata_rw_ctrl2, ctrl2);
+}
+
+static unsigned long
+cris_ide_reg_addr(unsigned long addr, int cs0, int cs1)
+{
+	reg_ata_rw_ctrl2 ctrl2 = {0};
+	ctrl2.addr = addr;
+	ctrl2.cs1 = cs1;
+	ctrl2.cs0 = cs0;
+	return REG_TYPE_CONV(int, reg_ata_rw_ctrl2, ctrl2);
+}
+
+static __init void
+cris_ide_reset(unsigned val)
+{
+	reg_ata_rw_ctrl0 ctrl0 = {0};
+	ctrl0.rst = val ? regk_ata_active : regk_ata_inactive;
+	REG_WR(ata, regi_ata, rw_ctrl0, ctrl0);
+}
+
+static __init void
+cris_ide_init(void)
+{
+	reg_ata_rw_ctrl0 ctrl0 = {0};
+	reg_ata_rw_intr_mask intr_mask = {0};
+
+	ctrl0.en = regk_ata_yes;
+	REG_WR(ata, regi_ata, rw_ctrl0, ctrl0);
+
+	intr_mask.bus0 = regk_ata_yes;
+	intr_mask.bus1 = regk_ata_yes;
+	intr_mask.bus2 = regk_ata_yes;
+	intr_mask.bus3 = regk_ata_yes;
+
+	REG_WR(ata, regi_ata, rw_intr_mask, intr_mask);
+
+	crisv32_request_dma(2, "ETRAX FS built-in ATA", DMA_VERBOSE_ON_ERROR, 0, dma_ata);
+	crisv32_request_dma(3, "ETRAX FS built-in ATA", DMA_VERBOSE_ON_ERROR, 0, dma_ata);
+
+	crisv32_pinmux_alloc_fixed(pinmux_ata);
+	crisv32_pinmux_alloc_fixed(pinmux_ata0);
+	crisv32_pinmux_alloc_fixed(pinmux_ata1);
+	crisv32_pinmux_alloc_fixed(pinmux_ata2);
+	crisv32_pinmux_alloc_fixed(pinmux_ata3);
+
+	DMA_RESET(regi_dma2);
+	DMA_ENABLE(regi_dma2);
+	DMA_RESET(regi_dma3);
+	DMA_ENABLE(regi_dma3);
+
+	DMA_WR_CMD (regi_dma2, regk_dma_set_w_size2);
+	DMA_WR_CMD (regi_dma3, regk_dma_set_w_size2);
+}
+
+static dma_descr_context mycontext __attribute__ ((__aligned__(32)));
+
+#define cris_dma_descr_type dma_descr_data
+#define cris_pio_read regk_ata_rd
+#define cris_ultra_mask 0x7
+#define MAX_DESCR_SIZE 0xffffffffUL
+
+static unsigned long
+cris_ide_get_reg(unsigned long reg)
+{
+	return (reg & 0x0e000000) >> 25;
+}
+
+static void
+cris_ide_fill_descriptor(cris_dma_descr_type *d, void* buf, unsigned int len, int last)
+{
+	d->buf = (char*)virt_to_phys(buf);
+	d->after = d->buf + len;
+	d->eol = last;
+}
+
+static void
+cris_ide_start_dma(ide_drive_t *drive, cris_dma_descr_type *d, int dir,int type,int len)
+{
+	reg_ata_rw_ctrl2 ctrl2 = REG_TYPE_CONV(reg_ata_rw_ctrl2, int, IDE_DATA_REG);
+	reg_ata_rw_trf_cnt trf_cnt = {0};
+
+	mycontext.saved_data = (dma_descr_data*)virt_to_phys(d);
+	mycontext.saved_data_buf = d->buf;
+	/* start the dma channel */
+	DMA_START_CONTEXT(dir ? regi_dma3 : regi_dma2, virt_to_phys(&mycontext));
+
+	/* initiate a multi word dma read using PIO handshaking */
+	trf_cnt.cnt = len >> 1;
+	/* Due to a "feature" the transfer count has to be one extra word for UDMA. */
+	if (type == TYPE_UDMA)
+		trf_cnt.cnt++;
+	REG_WR(ata, regi_ata, rw_trf_cnt, trf_cnt);
+
+	ctrl2.rw = dir ? regk_ata_rd : regk_ata_wr;
+	ctrl2.trf_mode = regk_ata_dma;
+	ctrl2.hsh = type == TYPE_PIO ? regk_ata_pio :
+	            type == TYPE_DMA ? regk_ata_dma : regk_ata_udma;
+	ctrl2.multi = regk_ata_yes;
+	ctrl2.dma_size = regk_ata_word;
+	REG_WR(ata, regi_ata, rw_ctrl2, ctrl2);
+}
+
+static void
+cris_ide_wait_dma(int dir)
+{
+	reg_dma_rw_stat status;
+	do
+	{
+		status = REG_RD(dma, dir ? regi_dma3 : regi_dma2, rw_stat);
+	} while(status.list_state != regk_dma_data_at_eol);
+}
+
+static int cris_dma_test_irq(ide_drive_t *drive)
+{
+	int intr = REG_RD_INT(ata, regi_ata, r_intr);
+	reg_ata_rw_ctrl2 ctrl2 = REG_TYPE_CONV(reg_ata_rw_ctrl2, int, IDE_DATA_REG);
+	return intr & (1 << ctrl2.sel) ? 1 : 0;
+}
+
+static void cris_ide_initialize_dma(int dir)
+{
+}
+
+#else
+/* CRISv10 specifics */
+#include <asm/arch/svinto.h>
+#include <asm/arch/io_interface_mux.h>
+
+/* 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_UDMA2_CYC    0 /* No UDMA supported, just to make it compile. */
+#define ATA_UDMA2_DVS    0
+#define ATA_UDMA1_CYC    0
+#define ATA_UDMA1_DVS    0
+#define ATA_UDMA0_CYC    0
+#define ATA_UDMA0_DVS    0
+#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
+
+int
+cris_ide_ack_intr(ide_hwif_t* hwif)
+{
+	return 1;
+}
+
+static inline int
+cris_ide_busy(void)
+{
+	return *R_ATA_STATUS_DATA & IO_MASK(R_ATA_STATUS_DATA, busy) ;
+}
+
+static inline int
+cris_ide_ready(void)
+{
+	return *R_ATA_STATUS_DATA & IO_MASK(R_ATA_STATUS_DATA, tr_rdy) ;
+}
+
+static inline int
+cris_ide_data_available(unsigned short* data)
+{
+	unsigned long status = *R_ATA_STATUS_DATA;
+	*data = (unsigned short)status;
+	return status & IO_MASK(R_ATA_STATUS_DATA, dav);
+}
+
+static void
+cris_ide_write_command(unsigned long command)
+{
+	*R_ATA_CTRL_DATA = command;
+}
+
+static void
+cris_ide_set_speed(int type, int setup, int strobe, int hold)
+{
+	static int pio_setup = ATA_PIO4_SETUP;
+	static int pio_strobe = ATA_PIO4_STROBE;
+	static int pio_hold = ATA_PIO4_HOLD;
+	static int dma_strobe = ATA_DMA2_STROBE;
+	static int dma_hold = ATA_DMA2_HOLD;
+
+	if (type == TYPE_PIO) {
+		pio_setup = setup;
+		pio_strobe = strobe;
+		pio_hold = hold;
+	} else if (type == TYPE_DMA) {
+		dma_strobe = strobe;
+	  dma_hold = hold;
+	}
+	*R_ATA_CONFIG = ( IO_FIELD( R_ATA_CONFIG, enable, 1 ) |
+	  IO_FIELD( R_ATA_CONFIG, dma_strobe, dma_strobe ) |
+		IO_FIELD( R_ATA_CONFIG, dma_hold,   dma_hold ) |
+		IO_FIELD( R_ATA_CONFIG, pio_setup,  pio_setup ) |
+		IO_FIELD( R_ATA_CONFIG, pio_strobe, pio_strobe ) |
+		IO_FIELD( R_ATA_CONFIG, pio_hold,   pio_hold ) );
+}
+
+static unsigned long
+cris_ide_base_address(int bus)
+{
+	return IO_FIELD(R_ATA_CTRL_DATA, sel, bus);
+}
+
+static unsigned long
+cris_ide_reg_addr(unsigned long addr, int cs0, int cs1)
+{
+	return IO_FIELD(R_ATA_CTRL_DATA, addr, addr) |
+	       IO_FIELD(R_ATA_CTRL_DATA, cs0, cs0) |
+	       IO_FIELD(R_ATA_CTRL_DATA, cs1, cs1);
+}
+
+static __init void
+cris_ide_reset(unsigned val)
+{
+#ifdef CONFIG_ETRAX_IDE_G27_RESET
+	REG_SHADOW_SET(R_PORT_G_DATA, port_g_data_shadow, 27, val);
+#endif
+#ifdef CONFIG_ETRAX_IDE_CSE1_16_RESET
+	REG_SHADOW_SET(port_cse1_addr, port_cse1_shadow, 16, val);
+#endif
+#ifdef CONFIG_ETRAX_IDE_CSP0_8_RESET
+	REG_SHADOW_SET(port_csp0_addr, port_csp0_shadow, 8, val);
+#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, val);
+#endif
+}
+
+static __init void
+cris_ide_init(void)
+{
+	volatile unsigned int dummy;
+
+	*R_ATA_CTRL_DATA = 0;
+	*R_ATA_TRANSFER_CNT = 0;
+	*R_ATA_CONFIG = 0;
+
+	if (cris_request_io_interface(if_ata, "ETRAX100LX IDE")) {
+		printk(KERN_CRIT "ide: Failed to get IO interface\n");
+		return;
+	} else if (cris_request_dma(ATA_TX_DMA_NBR,
+		                          "ETRAX100LX IDE TX",
+		                          DMA_VERBOSE_ON_ERROR,
+		                          dma_ata)) {
+		cris_free_io_interface(if_ata);
+		printk(KERN_CRIT "ide: Failed to get Tx DMA channel\n");
+		return;
+	} else if (cris_request_dma(ATA_RX_DMA_NBR,
+		                          "ETRAX100LX IDE RX",
+		                          DMA_VERBOSE_ON_ERROR,
+		                          dma_ata)) {
+		cris_free_dma(ATA_TX_DMA_NBR, "ETRAX100LX IDE Tx");
+		cris_free_io_interface(if_ata);
+		printk(KERN_CRIT "ide: Failed to get Rx DMA channel\n");
+		return;
+	}
+
+	/* 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 ));
+	*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 ) );
+
+	/* 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);
+}
+
+#define cris_dma_descr_type etrax_dma_descr
+#define cris_pio_read IO_STATE(R_ATA_CTRL_DATA, rw, read)
+#define cris_ultra_mask 0x0
+#define MAX_DESCR_SIZE 0x10000UL
+
+static unsigned long
+cris_ide_get_reg(unsigned long reg)
+{
+	return (reg & 0x0e000000) >> 25;
+}
+
+static void
+cris_ide_fill_descriptor(cris_dma_descr_type *d, void* buf, unsigned int len, int last)
+{
+	d->buf = virt_to_phys(buf);
+	d->sw_len = len == MAX_DESCR_SIZE ? 0 : len;
+	if (last)
+		d->ctrl |= d_eol;
+}
+
+static void cris_ide_start_dma(ide_drive_t *drive, cris_dma_descr_type *d, int dir, int type, int len)
+{
+	unsigned long cmd;
+
+	if (dir) {
+		/* 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(d);
+		*R_DMA_CH3_CMD   = IO_STATE(R_DMA_CH3_CMD, cmd, start);
+
+	} else {
+		*R_DMA_CH2_FIRST = virt_to_phys(d);
+		*R_DMA_CH2_CMD   = IO_STATE(R_DMA_CH2_CMD, cmd, start);
+	}
+
+	/* initiate a multi word dma read using DMA handshaking */
+
+	*R_ATA_TRANSFER_CNT =
+		IO_FIELD(R_ATA_TRANSFER_CNT, count, len >> 1);
+
+	cmd = dir ? IO_STATE(R_ATA_CTRL_DATA, rw, read) : IO_STATE(R_ATA_CTRL_DATA, rw, write);
+	cmd |= type == TYPE_PIO ? IO_STATE(R_ATA_CTRL_DATA, handsh, pio) :
+	                          IO_STATE(R_ATA_CTRL_DATA, handsh, dma);
+	*R_ATA_CTRL_DATA =
+		cmd |
+		IO_FIELD(R_ATA_CTRL_DATA, data, IDE_DATA_REG) |
+		IO_STATE(R_ATA_CTRL_DATA, src_dst,  dma)  |
+		IO_STATE(R_ATA_CTRL_DATA, multi,    on)   |
+		IO_STATE(R_ATA_CTRL_DATA, dma_size, word);
+}
+
+static void
+cris_ide_wait_dma(int dir)
+{
+	if (dir)
+		WAIT_DMA(ATA_RX_DMA_NBR);
+	else
+		WAIT_DMA(ATA_TX_DMA_NBR);
+}
+
+static int cris_dma_test_irq(ide_drive_t *drive)
+{
+	int intr = *R_IRQ_MASK0_RD;
+	int bus = IO_EXTRACT(R_ATA_CTRL_DATA, sel, IDE_DATA_REG);
+	return intr & (1 << (bus + IO_BITNR(R_IRQ_MASK0_RD, ata_irq0))) ? 1 : 0;
+}
+
+
+static void cris_ide_initialize_dma(int dir)
+{
+	if (dir)
+	{
+		RESET_DMA(ATA_RX_DMA_NBR); /* sometimes the DMA channel get stuck so we need to do this */
+		WAIT_DMA(ATA_RX_DMA_NBR);
+	}
+	else
+	{
+		RESET_DMA(ATA_TX_DMA_NBR); /* sometimes the DMA channel get stuck so we need to do this */
+		WAIT_DMA(ATA_TX_DMA_NBR);
+	}
+}
+
+#endif
+
+void
+cris_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 */
+	do {
+		timeleft--;
+	} while(timeleft && cris_ide_busy());
+
+	/*
+	 * 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);
+
+	cris_ide_write_command(reg|data); /* write data to the drive's register */
+
+	timeleft = IDE_REGISTER_TIMEOUT;
+	/* wait for transmitter ready */
+	do {
+		timeleft--;
+	} while(timeleft && !cris_ide_ready());
+}
+
+void
+cris_ide_outb(unsigned char data, unsigned long reg)
+{
+	cris_ide_outw(data, reg);
+}
+
+void
+cris_ide_outbsync(ide_drive_t *drive, u8 addr, unsigned long port)
+{
+	cris_ide_outw(addr, port);
+}
+
+unsigned short
+cris_ide_inw(unsigned long reg) {
+	int timeleft;
+	unsigned short val;
+
+	timeleft = IDE_REGISTER_TIMEOUT;
+	/* wait for busy flag */
+	do {
+		timeleft--;
+	} while(timeleft && cris_ide_busy());
+
+	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 (cris_ide_get_reg(reg) == IDE_STATUS_OFFSET)
+			return BUSY_STAT;
+		else
+			/* For other rare cases we assume 0 is good enough.  */
+			return 0;
+	}
+
+	cris_ide_write_command(reg | cris_pio_read);
+
+	timeleft = IDE_REGISTER_TIMEOUT;
+	/* wait for available */
+	do {
+		timeleft--;
+	} while(timeleft && !cris_ide_data_available(&val));
+
+	if(!timeleft)
+		return 0;
+
+	LOWDB(printk("inb: 0x%x from reg 0x%x\n", val & 0xff, reg));
+
+	return val;
+}
+
+unsigned char
+cris_ide_inb(unsigned long reg)
+{
+	return (unsigned char)cris_ide_inw(reg);
+}
+
+static int cris_dma_check (ide_drive_t *drive);
+static int cris_dma_end (ide_drive_t *drive);
+static int cris_dma_setup (ide_drive_t *drive);
+static void cris_dma_exec_cmd (ide_drive_t *drive, u8 command);
+static int cris_dma_test_irq(ide_drive_t *drive);
+static void cris_dma_start(ide_drive_t *drive);
+static void cris_ide_input_data (ide_drive_t *drive, void *, unsigned int);
+static void cris_ide_output_data (ide_drive_t *drive, void *, unsigned int);
+static void cris_atapi_input_bytes(ide_drive_t *drive, void *, unsigned int);
+static void cris_atapi_output_bytes(ide_drive_t *drive, void *, unsigned int);
+static int cris_dma_off (ide_drive_t *drive);
+static int cris_dma_on (ide_drive_t *drive);
+
+static void tune_cris_ide(ide_drive_t *drive, u8 pio)
+{
+	int setup, strobe, hold;
+
+	switch(pio)
+	{
+		case 0:
+			setup = ATA_PIO0_SETUP;
+			strobe = ATA_PIO0_STROBE;
+			hold = ATA_PIO0_HOLD;
+			break;
+		case 1:
+			setup = ATA_PIO1_SETUP;
+			strobe = ATA_PIO1_STROBE;
+			hold = ATA_PIO1_HOLD;
+			break;
+		case 2:
+			setup = ATA_PIO2_SETUP;
+			strobe = ATA_PIO2_STROBE;
+			hold = ATA_PIO2_HOLD;
+			break;
+		case 3:
+			setup = ATA_PIO3_SETUP;
+			strobe = ATA_PIO3_STROBE;
+			hold = ATA_PIO3_HOLD;
+			break;
+		case 4:
+			setup = ATA_PIO4_SETUP;
+			strobe = ATA_PIO4_STROBE;
+			hold = ATA_PIO4_HOLD;
+			break;
+		default:
+			return;
+	}
+
+	cris_ide_set_speed(TYPE_PIO, setup, strobe, hold);
+}
+
+static int speed_cris_ide(ide_drive_t *drive, u8 speed)
+{
+	int cyc = 0, dvs = 0, strobe = 0, hold = 0;
+
+	if (speed >= XFER_PIO_0 && speed <= XFER_PIO_4) {
+		tune_cris_ide(drive, speed - XFER_PIO_0);
+		return 0;
+	}
+
+	switch(speed)
+	{
+		case XFER_UDMA_0:
+			cyc = ATA_UDMA0_CYC;
+			dvs = ATA_UDMA0_DVS;
+			break;
+		case XFER_UDMA_1:
+			cyc = ATA_UDMA1_CYC;
+			dvs = ATA_UDMA1_DVS;
+			break;
+		case XFER_UDMA_2:
+			cyc = ATA_UDMA2_CYC;
+			dvs = ATA_UDMA2_DVS;
+			break;
+		case XFER_MW_DMA_0:
+			strobe = ATA_DMA0_STROBE;
+			hold = ATA_DMA0_HOLD;
+			break;
+		case XFER_MW_DMA_1:
+			strobe = ATA_DMA1_STROBE;
+			hold = ATA_DMA1_HOLD;
+			break;
+		case XFER_MW_DMA_2:
+			strobe = ATA_DMA2_STROBE;
+			hold = ATA_DMA2_HOLD;
+			break;
+		default:
+			return 0;
+	}
+
+	if (speed >= XFER_UDMA_0)
+		cris_ide_set_speed(TYPE_UDMA, cyc, dvs, 0);
+	else
+		cris_ide_set_speed(TYPE_DMA, 0, strobe, hold);
+
+	return 0;
+}
+
+void __init
+init_e100_ide (void)
+{
+	hw_regs_t hw;
+	int ide_offsets[IDE_NR_PORTS];
+	int h;
+	int i;
+
+	printk("ide: ETRAX FS built-in ATA DMA controller\n");
+
+	for (i = IDE_DATA_OFFSET; i <= IDE_STATUS_OFFSET; i++)
+		ide_offsets[i] = cris_ide_reg_addr(i, 0, 1);
+
+	/* the IDE control register is at ATA address 6, with CS1 active instead of CS0 */
+	ide_offsets[IDE_CONTROL_OFFSET] = cris_ide_reg_addr(6, 1, 0);
+
+	/* first fill in some stuff in the ide_hwifs fields */
+
+	for(h = 0; h < MAX_HWIFS; h++) {
+		ide_hwif_t *hwif = &ide_hwifs[h];
+		ide_setup_ports(&hw, cris_ide_base_address(h),
+		                ide_offsets,
+		                0, 0, cris_ide_ack_intr,
+		                ide_default_irq(0));
+		ide_register_hw(&hw, &hwif);
+		hwif->mmio = 2;
+		hwif->chipset = ide_etrax100;
+		hwif->tuneproc = &tune_cris_ide;
+		hwif->speedproc = &speed_cris_ide;
+		hwif->ata_input_data = &cris_ide_input_data;
+		hwif->ata_output_data = &cris_ide_output_data;
+		hwif->atapi_input_bytes = &cris_atapi_input_bytes;
+		hwif->atapi_output_bytes = &cris_atapi_output_bytes;
+		hwif->ide_dma_check = &cris_dma_check;
+		hwif->ide_dma_end = &cris_dma_end;
+		hwif->dma_setup = &cris_dma_setup;
+		hwif->dma_exec_cmd = &cris_dma_exec_cmd;
+		hwif->ide_dma_test_irq = &cris_dma_test_irq;
+		hwif->dma_start = &cris_dma_start;
+		hwif->OUTB = &cris_ide_outb;
+		hwif->OUTW = &cris_ide_outw;
+		hwif->OUTBSYNC = &cris_ide_outbsync;
+		hwif->INB = &cris_ide_inb;
+		hwif->INW = &cris_ide_inw;
+		hwif->ide_dma_host_off = &cris_dma_off;
+		hwif->ide_dma_host_on = &cris_dma_on;
+		hwif->ide_dma_off_quietly = &cris_dma_off;
+		hwif->udma_four = 0;
+		hwif->ultra_mask = cris_ultra_mask;
+		hwif->mwdma_mask = 0x07; /* Multiword DMA 0-2 */
+		hwif->swdma_mask = 0x07; /* Singleword DMA 0-2 */
+	}
+
+	/* Reset pulse */
+	cris_ide_reset(0);
+	udelay(25);
+	cris_ide_reset(1);
+
+	cris_ide_init();
+
+	cris_ide_set_speed(TYPE_PIO, ATA_PIO4_SETUP, ATA_PIO4_STROBE, ATA_PIO4_HOLD);
+	cris_ide_set_speed(TYPE_DMA, 0, ATA_DMA2_STROBE, ATA_DMA2_HOLD);
+	cris_ide_set_speed(TYPE_UDMA, ATA_UDMA2_CYC, ATA_UDMA2_DVS, 0);
+}
+
+static int cris_dma_off (ide_drive_t *drive)
+{
+	return 0;
+}
+
+static int cris_dma_on (ide_drive_t *drive)
+{
+	return 0;
+}
+
+
+static cris_dma_descr_type mydescr __attribute__ ((__aligned__(16)));
+
+/*
+ * 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
+cris_atapi_input_bytes (ide_drive_t *drive, void *buffer, unsigned int bytecount)
+{
+	D(printk("atapi_input_bytes, buffer 0x%x, count %d\n",
+	         buffer, bytecount));
+
+	if(bytecount & 1) {
+		printk("warning, odd bytecount in cdrom_in_bytes = %d.\n", bytecount);
+		bytecount++; /* to round off */
+	}
+
+	/* setup DMA and start transfer */
+
+	cris_ide_fill_descriptor(&mydescr, buffer, bytecount, 1);
+	cris_ide_start_dma(drive, &mydescr, 1, TYPE_PIO, bytecount);
+
+	/* wait for completion */
+	LED_DISK_READ(1);
+	cris_ide_wait_dma(1);
+	LED_DISK_READ(0);
+}
+
+static void
+cris_atapi_output_bytes (ide_drive_t *drive, void *buffer, unsigned int bytecount)
+{
+	D(printk("atapi_output_bytes, buffer 0x%x, count %d\n",
+	         buffer, bytecount));
+
+	if(bytecount & 1) {
+		printk("odd bytecount %d in atapi_out_bytes!\n", bytecount);
+		bytecount++;
+	}
+
+	cris_ide_fill_descriptor(&mydescr, buffer, bytecount, 1);
+	cris_ide_start_dma(drive, &mydescr, 0, TYPE_PIO, bytecount);
+
+	/* wait for completion */
+
+	LED_DISK_WRITE(1);
+	LED_DISK_READ(1);
+	cris_ide_wait_dma(0);
+	LED_DISK_WRITE(0);
+}
+
+/*
+ * This is used for most PIO data transfers *from* the IDE interface
+ */
+static void
+cris_ide_input_data (ide_drive_t *drive, void *buffer, unsigned int wcount)
+{
+	cris_atapi_input_bytes(drive, buffer, wcount << 2);
+}
+
+/*
+ * This is used for most PIO data transfers *to* the IDE interface
+ */
+static void
+cris_ide_output_data (ide_drive_t *drive, void *buffer, unsigned int wcount)
+{
+	cris_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 cris_dma_descr_type ata_descrs[MAX_DMA_DESCRS] __attribute__ ((__aligned__(16)));
+static unsigned int ata_tot_size;
+
+/*
+ * cris_ide_build_dmatable() prepares a dma request.
+ * Returns 0 if all went okay, returns 1 otherwise.
+ */
+static int cris_ide_build_dmatable (ide_drive_t *drive)
+{
+	ide_hwif_t *hwif = drive->hwif;
+	struct scatterlist* sg;
+	struct request *rq  = drive->hwif->hwgroup->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 - rw_trf_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 rw_trf_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 > MAX_DESCR_SIZE it has to be splitted into new descriptors. Since we
+                   don't handle size > 131072 only one split is necessary */
+
+		if(size > MAX_DESCR_SIZE) {
+			cris_ide_fill_descriptor(&ata_descrs[count], (void*)addr, MAX_DESCR_SIZE, 0);
+			count++;
+			ata_tot_size += MAX_DESCR_SIZE;
+			size -= MAX_DESCR_SIZE;
+			addr += MAX_DESCR_SIZE;
+		}
+
+		cris_ide_fill_descriptor(&ata_descrs[count], (void*)addr, size,i ? 0 : 1);
+		count++;
+		ata_tot_size += size;
+	}
+
+	if (count) {
+		/* 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 cris_config_drive_for_dma (ide_drive_t *drive)
+{
+	u8 speed = ide_dma_speed(drive, 1);
+
+	if (!speed)
+		return 0;
+
+	speed_cris_ide(drive, speed);
+	ide_config_drive_speed(drive, speed);
+
+	return ide_dma_enable(drive);
+}
+
+/*
+ * cris_dma_intr() is the handler for disk read/write DMA interrupts
+ */
+static ide_startstop_t cris_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.
+ *
+ * For ATAPI devices, we just prepare for DMA and return. The caller should
+ * then issue the packet command to the drive and call us again with
+ * cris_dma_start afterwards.
+ *
+ * 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 cris_dma_check(ide_drive_t *drive)
+{
+	ide_hwif_t *hwif = drive->hwif;
+	struct hd_driveid* id = drive->id;
+
+	if (id && (id->capability & 1)) {
+		if (ide_use_dma(drive)) {
+			if (cris_config_drive_for_dma(drive))
+				return hwif->ide_dma_on(drive);
+		}
+	}
+
+	return hwif->ide_dma_off_quietly(drive);
+}
+
+static int cris_dma_end(ide_drive_t *drive)
+{
+	drive->waiting_for_dma = 0;
+	return 0;
+}
+
+static int cris_dma_setup(ide_drive_t *drive)
+{
+	struct request *rq = drive->hwif->hwgroup->rq;
+
+	cris_ide_initialize_dma(!rq_data_dir(rq));
+	if (cris_ide_build_dmatable (drive)) {
+		ide_map_sg(drive, rq);
+		return 1;
+	}
+
+	drive->waiting_for_dma = 1;
+	return 0;
+}
+
+static void cris_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, &cris_dma_intr, WAIT_CMD, NULL);
+
+	/* issue cmd to drive */
+	cris_ide_outb(command, IDE_COMMAND_REG);
+}
+
+static void cris_dma_start(ide_drive_t *drive)
+{
+	struct request *rq = drive->hwif->hwgroup->rq;
+	int writing = rq_data_dir(rq);
+	int type = TYPE_DMA;
+
+	if (drive->current_speed >= XFER_UDMA_0)
+		type = TYPE_UDMA;
+
+	cris_ide_start_dma(drive, &ata_descrs[0], writing ? 0 : 1, type, ata_tot_size);
+
+	if (writing) {
+		LED_DISK_WRITE(1);
+	} else {
+		LED_DISK_READ(1);
+	}
+}