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authorAxel Lin <axel.lin@ingics.com>2014-03-21 13:24:14 +0800
committerMark Brown <broonie@linaro.org>2014-03-21 17:49:04 +0000
commitfb534f10755954827a4b71b9a21f9b5fa93707a9 (patch)
treec61737b35f0d2ccb815969be694e73d27a8aa4f4 /drivers/spi
parent8120ff8c48396a75cc9e5fa26a7a476479003fab (diff)
spi: nuc900: Fix setting multiple bits settings in register
The correct way to set multiple bits settings is always clear these bit fields before set new settings. Current code does not cause problem because the reset value of these bit fields are 0, and these settings only set once during probe. Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Mark Brown <broonie@linaro.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-nuc900.c18
1 files changed, 8 insertions, 10 deletions
diff --git a/drivers/spi/spi-nuc900.c b/drivers/spi/spi-nuc900.c
index 6d36c35c86f5..f12e27cdbf49 100644
--- a/drivers/spi/spi-nuc900.c
+++ b/drivers/spi/spi-nuc900.c
@@ -38,7 +38,9 @@
/* usi register bit */
#define ENINT (0x01 << 17)
#define ENFLG (0x01 << 16)
+#define SLEEP (0x0f << 12)
#define TXNUM (0x03 << 8)
+#define TXBITLEN (0x1f << 3)
#define TXNEG (0x01 << 2)
#define RXNEG (0x01 << 1)
#define LSB (0x01 << 10)
@@ -116,19 +118,16 @@ static void nuc900_spi_chipsel(struct spi_device *spi, int value)
}
}
-static void nuc900_spi_setup_txnum(struct nuc900_spi *hw,
- unsigned int txnum)
+static void nuc900_spi_setup_txnum(struct nuc900_spi *hw, unsigned int txnum)
{
unsigned int val;
unsigned long flags;
spin_lock_irqsave(&hw->lock, flags);
- val = __raw_readl(hw->regs + USI_CNT);
+ val = __raw_readl(hw->regs + USI_CNT) & ~TXNUM;
- if (!txnum)
- val &= ~TXNUM;
- else
+ if (txnum)
val |= txnum << 0x08;
__raw_writel(val, hw->regs + USI_CNT);
@@ -145,7 +144,7 @@ static void nuc900_spi_setup_txbitlen(struct nuc900_spi *hw,
spin_lock_irqsave(&hw->lock, flags);
- val = __raw_readl(hw->regs + USI_CNT);
+ val = __raw_readl(hw->regs + USI_CNT) & ~TXBITLEN;
val |= (txbitlen << 0x03);
@@ -284,12 +283,11 @@ static void nuc900_set_sleep(struct nuc900_spi *hw, unsigned int sleep)
spin_lock_irqsave(&hw->lock, flags);
- val = __raw_readl(hw->regs + USI_CNT);
+ val = __raw_readl(hw->regs + USI_CNT) & ~SLEEP;
if (sleep)
val |= (sleep << 12);
- else
- val &= ~(0x0f << 12);
+
__raw_writel(val, hw->regs + USI_CNT);
spin_unlock_irqrestore(&hw->lock, flags);