diff options
Diffstat (limited to 'drivers/ide/ide-xfer-mode.c')
| -rw-r--r-- | drivers/ide/ide-xfer-mode.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/drivers/ide/ide-xfer-mode.c b/drivers/ide/ide-xfer-mode.c new file mode 100644 index 0000000..6910f6a --- /dev/null +++ b/drivers/ide/ide-xfer-mode.c @@ -0,0 +1,246 @@ +#include <linux/types.h> +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/ide.h> +#include <linux/bitops.h> + +static const char *udma_str[] = + { "UDMA/16", "UDMA/25", "UDMA/33", "UDMA/44", + "UDMA/66", "UDMA/100", "UDMA/133", "UDMA7" }; +static const char *mwdma_str[] = + { "MWDMA0", "MWDMA1", "MWDMA2" }; +static const char *swdma_str[] = + { "SWDMA0", "SWDMA1", "SWDMA2" }; +static const char *pio_str[] = + { "PIO0", "PIO1", "PIO2", "PIO3", "PIO4", "PIO5" }; + +/** + * ide_xfer_verbose - return IDE mode names + * @mode: transfer mode + * + * Returns a constant string giving the name of the mode + * requested. + */ + +const char *ide_xfer_verbose(u8 mode) +{ + const char *s; + u8 i = mode & 0xf; + + if (mode >= XFER_UDMA_0 && mode <= XFER_UDMA_7) + s = udma_str[i]; + else if (mode >= XFER_MW_DMA_0 && mode <= XFER_MW_DMA_2) + s = mwdma_str[i]; + else if (mode >= XFER_SW_DMA_0 && mode <= XFER_SW_DMA_2) + s = swdma_str[i]; + else if (mode >= XFER_PIO_0 && mode <= XFER_PIO_5) + s = pio_str[i & 0x7]; + else if (mode == XFER_PIO_SLOW) + s = "PIO SLOW"; + else + s = "XFER ERROR"; + + return s; +} +EXPORT_SYMBOL(ide_xfer_verbose); + +/** + * ide_get_best_pio_mode - get PIO mode from drive + * @drive: drive to consider + * @mode_wanted: preferred mode + * @max_mode: highest allowed mode + * + * This routine returns the recommended PIO settings for a given drive, + * based on the drive->id information and the ide_pio_blacklist[]. + * + * Drive PIO mode is auto-selected if 255 is passed as mode_wanted. + * This is used by most chipset support modules when "auto-tuning". + */ + +u8 ide_get_best_pio_mode(ide_drive_t *drive, u8 mode_wanted, u8 max_mode) +{ + u16 *id = drive->id; + int pio_mode = -1, overridden = 0; + + if (mode_wanted != 255) + return min_t(u8, mode_wanted, max_mode); + + if ((drive->hwif->host_flags & IDE_HFLAG_PIO_NO_BLACKLIST) == 0) + pio_mode = ide_scan_pio_blacklist((char *)&id[ATA_ID_PROD]); + + if (pio_mode != -1) { + printk(KERN_INFO "%s: is on PIO blacklist\n", drive->name); + } else { + pio_mode = id[ATA_ID_OLD_PIO_MODES] >> 8; + if (pio_mode > 2) { /* 2 is maximum allowed tPIO value */ + pio_mode = 2; + overridden = 1; + } + + if (id[ATA_ID_FIELD_VALID] & 2) { /* ATA2? */ + if (ata_id_has_iordy(id)) { + if (id[ATA_ID_PIO_MODES] & 7) { + overridden = 0; + if (id[ATA_ID_PIO_MODES] & 4) + pio_mode = 5; + else if (id[ATA_ID_PIO_MODES] & 2) + pio_mode = 4; + else + pio_mode = 3; + } + } + } + + if (overridden) + printk(KERN_INFO "%s: tPIO > 2, assuming tPIO = 2\n", + drive->name); + } + + if (pio_mode > max_mode) + pio_mode = max_mode; + + return pio_mode; +} +EXPORT_SYMBOL_GPL(ide_get_best_pio_mode); + +int ide_set_pio_mode(ide_drive_t *drive, const u8 mode) +{ + ide_hwif_t *hwif = drive->hwif; + const struct ide_port_ops *port_ops = hwif->port_ops; + + if (hwif->host_flags & IDE_HFLAG_NO_SET_MODE) + return 0; + + if (port_ops == NULL || port_ops->set_pio_mode == NULL) + return -1; + + /* + * TODO: temporary hack for some legacy host drivers that didn't + * set transfer mode on the device in ->set_pio_mode method... + */ + if (port_ops->set_dma_mode == NULL) { + port_ops->set_pio_mode(drive, mode - XFER_PIO_0); + return 0; + } + + if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) { + if (ide_config_drive_speed(drive, mode)) + return -1; + port_ops->set_pio_mode(drive, mode - XFER_PIO_0); + return 0; + } else { + port_ops->set_pio_mode(drive, mode - XFER_PIO_0); + return ide_config_drive_speed(drive, mode); + } +} + +int ide_set_dma_mode(ide_drive_t *drive, const u8 mode) +{ + ide_hwif_t *hwif = drive->hwif; + const struct ide_port_ops *port_ops = hwif->port_ops; + + if (hwif->host_flags & IDE_HFLAG_NO_SET_MODE) + return 0; + + if (port_ops == NULL || port_ops->set_dma_mode == NULL) + return -1; + + if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) { + if (ide_config_drive_speed(drive, mode)) + return -1; + port_ops->set_dma_mode(drive, mode); + return 0; + } else { + port_ops->set_dma_mode(drive, mode); + return ide_config_drive_speed(drive, mode); + } +} +EXPORT_SYMBOL_GPL(ide_set_dma_mode); + +/* req_pio == "255" for auto-tune */ +void ide_set_pio(ide_drive_t *drive, u8 req_pio) +{ + ide_hwif_t *hwif = drive->hwif; + const struct ide_port_ops *port_ops = hwif->port_ops; + u8 host_pio, pio; + + if (port_ops == NULL || port_ops->set_pio_mode == NULL || + (hwif->host_flags & IDE_HFLAG_NO_SET_MODE)) + return; + + BUG_ON(hwif->pio_mask == 0x00); + + host_pio = fls(hwif->pio_mask) - 1; + + pio = ide_get_best_pio_mode(drive, req_pio, host_pio); + + /* + * TODO: + * - report device max PIO mode + * - check req_pio != 255 against device max PIO mode + */ + printk(KERN_DEBUG "%s: host max PIO%d wanted PIO%d%s selected PIO%d\n", + drive->name, host_pio, req_pio, + req_pio == 255 ? "(auto-tune)" : "", pio); + + (void)ide_set_pio_mode(drive, XFER_PIO_0 + pio); +} +EXPORT_SYMBOL_GPL(ide_set_pio); + +/** + * ide_rate_filter - filter transfer mode + * @drive: IDE device + * @speed: desired speed + * + * Given the available transfer modes this function returns + * the best available speed at or below the speed requested. + * + * TODO: check device PIO capabilities + */ + +static u8 ide_rate_filter(ide_drive_t *drive, u8 speed) +{ + ide_hwif_t *hwif = drive->hwif; + u8 mode = ide_find_dma_mode(drive, speed); + + if (mode == 0) { + if (hwif->pio_mask) + mode = fls(hwif->pio_mask) - 1 + XFER_PIO_0; + else + mode = XFER_PIO_4; + } + +/* printk("%s: mode 0x%02x, speed 0x%02x\n", __func__, mode, speed); */ + + return min(speed, mode); +} + +/** + * ide_set_xfer_rate - set transfer rate + * @drive: drive to set + * @rate: speed to attempt to set + * + * General helper for setting the speed of an IDE device. This + * function knows about user enforced limits from the configuration + * which ->set_pio_mode/->set_dma_mode does not. + */ + +int ide_set_xfer_rate(ide_drive_t *drive, u8 rate) +{ + ide_hwif_t *hwif = drive->hwif; + const struct ide_port_ops *port_ops = hwif->port_ops; + + if (port_ops == NULL || port_ops->set_dma_mode == NULL || + (hwif->host_flags & IDE_HFLAG_NO_SET_MODE)) + return -1; + + rate = ide_rate_filter(drive, rate); + + BUG_ON(rate < XFER_PIO_0); + + if (rate >= XFER_PIO_0 && rate <= XFER_PIO_5) + return ide_set_pio_mode(drive, rate); + + return ide_set_dma_mode(drive, rate); +} |
