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-rw-r--r--drivers/spi/omap2_mcspi.c29
1 files changed, 18 insertions, 11 deletions
diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c
index abb1ffbf3d20..1a2d0b8bdd6a 100644
--- a/drivers/spi/omap2_mcspi.c
+++ b/drivers/spi/omap2_mcspi.c
@@ -651,6 +651,17 @@ out:
651 return count - c; 651 return count - c;
652} 652}
653 653
654static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
655{
656 u32 div;
657
658 for (div = 0; div < 15; div++)
659 if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
660 return div;
661
662 return 15;
663}
664
654/* called only when no transfer is active to this device */ 665/* called only when no transfer is active to this device */
655static int omap2_mcspi_setup_transfer(struct spi_device *spi, 666static int omap2_mcspi_setup_transfer(struct spi_device *spi,
656 struct spi_transfer *t) 667 struct spi_transfer *t)
@@ -673,12 +684,8 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
673 if (t && t->speed_hz) 684 if (t && t->speed_hz)
674 speed_hz = t->speed_hz; 685 speed_hz = t->speed_hz;
675 686
676 if (speed_hz) { 687 speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
677 while (div <= 15 && (OMAP2_MCSPI_MAX_FREQ / (1 << div)) 688 div = omap2_mcspi_calc_divisor(speed_hz);
678 > speed_hz)
679 div++;
680 } else
681 div = 15;
682 689
683 l = mcspi_cached_chconf0(spi); 690 l = mcspi_cached_chconf0(spi);
684 691
@@ -715,7 +722,7 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
715 mcspi_write_chconf0(spi, l); 722 mcspi_write_chconf0(spi, l);
716 723
717 dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n", 724 dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
718 OMAP2_MCSPI_MAX_FREQ / (1 << div), 725 OMAP2_MCSPI_MAX_FREQ >> div,
719 (spi->mode & SPI_CPHA) ? "trailing" : "leading", 726 (spi->mode & SPI_CPHA) ? "trailing" : "leading",
720 (spi->mode & SPI_CPOL) ? "inverted" : "normal"); 727 (spi->mode & SPI_CPOL) ? "inverted" : "normal");
721 728
@@ -1015,10 +1022,10 @@ static int omap2_mcspi_transfer(struct spi_device *spi, struct spi_message *m)
1015 t->bits_per_word); 1022 t->bits_per_word);
1016 return -EINVAL; 1023 return -EINVAL;
1017 } 1024 }
1018 if (t->speed_hz && t->speed_hz < OMAP2_MCSPI_MAX_FREQ/(1<<16)) { 1025 if (t->speed_hz && t->speed_hz < (OMAP2_MCSPI_MAX_FREQ >> 15)) {
1019 dev_dbg(&spi->dev, "%d Hz max exceeds %d\n", 1026 dev_dbg(&spi->dev, "speed_hz %d below minimum %d Hz\n",
1020 t->speed_hz, 1027 t->speed_hz,
1021 OMAP2_MCSPI_MAX_FREQ/(1<<16)); 1028 OMAP2_MCSPI_MAX_FREQ >> 15);
1022 return -EINVAL; 1029 return -EINVAL;
1023 } 1030 }
1024 1031