From: Ryo Kataoka <[email protected]> In case of repeated START condition, the restart has to be kicked before clear status (MSR register). If it is kicked after clear status, R-Car I2C may transfer data (TXD register) or receive data (RXD register) instead of transferring slave address (MAR register).
Signed-off-by: Ryo Kataoka <[email protected]> Signed-off-by: Yoshihiro Kaneko <[email protected]> --- This patch is based on i2c/for-next branch of Wolfram Sang's linux tree. drivers/i2c/busses/i2c-rcar.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index d8361da..8cc7bd7 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -2,6 +2,7 @@ * Driver for the Renesas RCar I2C unit * * Copyright (C) 2014 Wolfram Sang <[email protected]> + * Copyright (C) 2013-2014 Renesas Electronics Corporation * * Copyright (C) 2012-14 Renesas Solutions Corp. * Kuninori Morimoto <[email protected]> @@ -99,6 +100,7 @@ #define ID_DONE (1 << 2) #define ID_ARBLOST (1 << 3) #define ID_NACK (1 << 4) +#define ID_FIRST_MSG (1 << 5) enum rcar_i2c_type { I2C_RCAR_GEN1, @@ -125,6 +127,7 @@ struct rcar_i2c_priv { #define rcar_i2c_is_recv(p) ((p)->msg->flags & I2C_M_RD) #define rcar_i2c_flags_set(p, f) ((p)->flags |= (f)) +#define rcar_i2c_flags_clr(p, f) ((p)->flags &= ~(f)) #define rcar_i2c_flags_has(p, f) ((p)->flags & (f)) #define LOOP_TIMEOUT 1024 @@ -257,8 +260,14 @@ static void rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv) int read = !!rcar_i2c_is_recv(priv); rcar_i2c_write(priv, ICMAR, (priv->msg->addr << 1) | read); - rcar_i2c_write(priv, ICMSR, 0); - rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START); + if (rcar_i2c_flags_has(priv, ID_FIRST_MSG)) { /* start */ + rcar_i2c_write(priv, ICMSR, 0); + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START); + rcar_i2c_flags_clr(priv, ID_FIRST_MSG); + } else { /* restart */ + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START); + rcar_i2c_write(priv, ICMSR, 0); + } rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND); } @@ -523,6 +532,8 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, priv->msg = &msgs[i]; priv->pos = 0; priv->flags = 0; + if (i == 0) + rcar_i2c_flags_set(priv, ID_FIRST_MSG); if (i == num - 1) rcar_i2c_flags_set(priv, ID_LAST_MSG); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
