UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

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>
This commit is contained in:
Wolfram Sang 2019-02-05 14:37:25 +01:00 committed by Wolfram Sang
parent 60c1d5605b
commit 18769445ca
1 changed files with 6 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
drivers/i2c/busses/i2c-rcar.c
View File

@ -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);