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>

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);