/* $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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* 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)); } }