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authorSergei Shtylyov <sshtylyov@ru.mvista.com>2009-12-07 23:38:11 +0400
committerJeff Garzik <jgarzik@redhat.com>2010-03-01 14:58:43 -0500
commitfd5e62e22db29a067d3f26ba54caac308eb5e3a8 (patch)
tree5e2c85e6f923d3ad50cd72b8707afc66a6bcdb2c
parent859faa875ed6760fcdfaf6f1fec1155a7e43dc21 (diff)
pata_hpt{37x|3x2n}: improve timing register documentation
Describe UDMA timing bits 18-20 and 21 separately; add a note to bit 31 about it being meaningful for PIO only. Reformat the whole comment, while at it... Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
-rw-r--r--drivers/ata/pata_hpt37x.c31
-rw-r--r--drivers/ata/pata_hpt3x2n.c31
2 files changed, 30 insertions, 32 deletions
diff --git a/drivers/ata/pata_hpt37x.c b/drivers/ata/pata_hpt37x.c
index 9b191763e6e5..228dc1a8992f 100644
--- a/drivers/ata/pata_hpt37x.c
+++ b/drivers/ata/pata_hpt37x.c
@@ -39,25 +39,24 @@ struct hpt_chip {
/* key for bus clock timings
* bit
- * 0:3 data_high_time. inactive time of DIOW_/DIOR_ for PIO and MW
- * DMA. cycles = value + 1
- * 4:8 data_low_time. active time of DIOW_/DIOR_ for PIO and MW
- * DMA. cycles = value + 1
- * 9:12 cmd_high_time. inactive time of DIOW_/DIOR_ during task file
+ * 0:3 data_high_time. Inactive time of DIOW_/DIOR_ for PIO and MW DMA.
+ * cycles = value + 1
+ * 4:8 data_low_time. Active time of DIOW_/DIOR_ for PIO and MW DMA.
+ * cycles = value + 1
+ * 9:12 cmd_high_time. Inactive time of DIOW_/DIOR_ during task file
* register access.
- * 13:17 cmd_low_time. active time of DIOW_/DIOR_ during task file
+ * 13:17 cmd_low_time. Active time of DIOW_/DIOR_ during task file
* register access.
- * 18:21 udma_cycle_time. clock freq and clock cycles for UDMA xfer.
- * during task file register access.
- * 22:24 pre_high_time. time to initialize 1st cycle for PIO and MW DMA
- * xfer.
- * 25:27 cmd_pre_high_time. time to initialize 1st PIO cycle for task
+ * 18:20 udma_cycle_time. Clock cycles for UDMA xfer.
+ * 21 CLK frequency for UDMA: 0=ATA clock, 1=dual ATA clock.
+ * 22:24 pre_high_time. Time to initialize 1st cycle for PIO and MW DMA xfer.
+ * 25:27 cmd_pre_high_time. Time to initialize 1st PIO cycle for task file
* register access.
- * 28 UDMA enable
- * 29 DMA enable
- * 30 PIO_MST enable. if set, the chip is in bus master mode during
- * PIO.
- * 31 FIFO enable.
+ * 28 UDMA enable.
+ * 29 DMA enable.
+ * 30 PIO_MST enable. If set, the chip is in bus master mode during
+ * PIO xfer.
+ * 31 FIFO enable. Only for PIO.
*/
static struct hpt_clock hpt37x_timings_33[] = {
diff --git a/drivers/ata/pata_hpt3x2n.c b/drivers/ata/pata_hpt3x2n.c
index b131c8f824d7..4a291221f277 100644
--- a/drivers/ata/pata_hpt3x2n.c
+++ b/drivers/ata/pata_hpt3x2n.c
@@ -45,25 +45,24 @@ struct hpt_chip {
/* key for bus clock timings
* bit
- * 0:3 data_high_time. inactive time of DIOW_/DIOR_ for PIO and MW
- * DMA. cycles = value + 1
- * 4:8 data_low_time. active time of DIOW_/DIOR_ for PIO and MW
- * DMA. cycles = value + 1
- * 9:12 cmd_high_time. inactive time of DIOW_/DIOR_ during task file
+ * 0:3 data_high_time. Inactive time of DIOW_/DIOR_ for PIO and MW DMA.
+ * cycles = value + 1
+ * 4:8 data_low_time. Active time of DIOW_/DIOR_ for PIO and MW DMA.
+ * cycles = value + 1
+ * 9:12 cmd_high_time. Inactive time of DIOW_/DIOR_ during task file
* register access.
- * 13:17 cmd_low_time. active time of DIOW_/DIOR_ during task file
+ * 13:17 cmd_low_time. Active time of DIOW_/DIOR_ during task file
* register access.
- * 18:21 udma_cycle_time. clock freq and clock cycles for UDMA xfer.
- * during task file register access.
- * 22:24 pre_high_time. time to initialize 1st cycle for PIO and MW DMA
- * xfer.
- * 25:27 cmd_pre_high_time. time to initialize 1st PIO cycle for task
+ * 18:20 udma_cycle_time. Clock cycles for UDMA xfer.
+ * 21 CLK frequency for UDMA: 0=ATA clock, 1=dual ATA clock.
+ * 22:24 pre_high_time. Time to initialize 1st cycle for PIO and MW DMA xfer.
+ * 25:27 cmd_pre_high_time. Time to initialize 1st PIO cycle for task file
* register access.
- * 28 UDMA enable
- * 29 DMA enable
- * 30 PIO_MST enable. if set, the chip is in bus master mode during
- * PIO.
- * 31 FIFO enable.
+ * 28 UDMA enable.
+ * 29 DMA enable.
+ * 30 PIO_MST enable. If set, the chip is in bus master mode during
+ * PIO xfer.
+ * 31 FIFO enable. Only for PIO.
*/
/* 66MHz DPLL clocks */