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path: root/drivers/ide/ide-xfer-mode.c
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-rw-r--r--drivers/ide/ide-xfer-mode.c246
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);
+}
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