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path: root/drivers/spi/spi-armada-3700.c
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Diffstat (limited to 'drivers/spi/spi-armada-3700.c')
-rw-r--r--drivers/spi/spi-armada-3700.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/spi/spi-armada-3700.c b/drivers/spi/spi-armada-3700.c
index 77fe55ce790c..d65345312527 100644
--- a/drivers/spi/spi-armada-3700.c
+++ b/drivers/spi/spi-armada-3700.c
@@ -79,6 +79,7 @@
#define A3700_SPI_BYTE_LEN BIT(5)
#define A3700_SPI_CLK_PRESCALE BIT(0)
#define A3700_SPI_CLK_PRESCALE_MASK (0x1f)
+#define A3700_SPI_CLK_EVEN_OFFS (0x10)
#define A3700_SPI_WFIFO_THRS_BIT 28
#define A3700_SPI_RFIFO_THRS_BIT 24
@@ -220,6 +221,13 @@ static void a3700_spi_clock_set(struct a3700_spi *a3700_spi,
prescale = DIV_ROUND_UP(clk_get_rate(a3700_spi->clk), speed_hz);
+ /* For prescaler values over 15, we can only set it by steps of 2.
+ * Starting from A3700_SPI_CLK_EVEN_OFFS, we set values from 0 up to
+ * 30. We only use this range from 16 to 30.
+ */
+ if (prescale > 15)
+ prescale = A3700_SPI_CLK_EVEN_OFFS + DIV_ROUND_UP(prescale, 2);
+
val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
val = val & ~A3700_SPI_CLK_PRESCALE_MASK;

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