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author | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2019-02-05 14:37:25 +0100 |
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committer | Wolfram Sang <wsa@the-dreams.de> | 2019-02-08 22:30:46 +0100 |
commit | 18769445ca55c2277d29e35ffda7e9a206b1758f (patch) | |
tree | e03145351230eb7f48733731600e91f90666c7b5 /drivers/i2c | |
parent | i2c: gpio: merge two very similar comments (diff) | |
download | linux-18769445ca55c2277d29e35ffda7e9a206b1758f.tar.xz linux-18769445ca55c2277d29e35ffda7e9a206b1758f.zip |
i2c: rcar: refactor TCYC handling
The latest documentation made it clear that we need to initialize the
TCYC value independently of DMA. The old code used TCYC06 (wrongly) for
non-DMA transfers. The new code sets TCYC up independently from DMA.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r-- | drivers/i2c/busses/i2c-rcar.c | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 498ba4b87833..dd52a068b140 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -39,8 +39,8 @@ #define ICSAR 0x1C /* slave address */ #define ICMAR 0x20 /* master address */ #define ICRXTX 0x24 /* data port */ -#define ICDMAER 0x3c /* DMA enable */ -#define ICFBSCR 0x38 /* first bit setup cycle */ +#define ICFBSCR 0x38 /* first bit setup cycle (Gen3) */ +#define ICDMAER 0x3c /* DMA enable (Gen3) */ /* ICSCR */ #define SDBS (1 << 3) /* slave data buffer select */ @@ -83,7 +83,6 @@ #define TMDMAE (1 << 0) /* DMA Master Transmitted Enable */ /* ICFBSCR */ -#define TCYC06 0x04 /* 6*Tcyc delay 1st bit between SDA and SCL */ #define TCYC17 0x0f /* 17*Tcyc delay 1st bit between SDA and SCL */ @@ -212,6 +211,10 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv) rcar_i2c_write(priv, ICMSR, 0); /* start clock */ rcar_i2c_write(priv, ICCCR, priv->icccr); + + if (priv->devtype == I2C_RCAR_GEN3) + rcar_i2c_write(priv, ICFBSCR, TCYC17); + } static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv) @@ -363,9 +366,6 @@ static void rcar_i2c_dma_unmap(struct rcar_i2c_priv *priv) /* Disable DMA Master Received/Transmitted */ rcar_i2c_write(priv, ICDMAER, 0); - /* Reset default delay */ - rcar_i2c_write(priv, ICFBSCR, TCYC06); - dma_unmap_single(chan->device->dev, sg_dma_address(&priv->sg), sg_dma_len(&priv->sg), priv->dma_direction); @@ -461,9 +461,6 @@ static void rcar_i2c_dma(struct rcar_i2c_priv *priv) return; } - /* Set delay for DMA operations */ - rcar_i2c_write(priv, ICFBSCR, TCYC17); - /* Enable DMA Master Received/Transmitted */ if (read) rcar_i2c_write(priv, ICDMAER, RMDMAE); |