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 <[email protected]> Signed-off-by: Wolfram Sang <[email protected]> --- Change since v1: improve commit message per Simon's comment. drivers/i2c/busses/i2c-rcar.c | 15 ++++++--------- 1 file 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); -- 2.19.1
