diff options
| -rw-r--r-- | drivers/i2c/busses/i2c-rcar.c | 34 |
1 files changed, 20 insertions, 14 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index a9f1880e2eae..43ad933df0f0 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -113,9 +113,10 @@ #define ID_ARBLOST (1 << 3) #define ID_NACK (1 << 4) /* persistent flags */ +#define ID_P_REP_AFTER_RD BIT(29) #define ID_P_NO_RXDMA BIT(30) /* HW forbids RXDMA sometimes */ #define ID_P_PM_BLOCKED BIT(31) -#define ID_P_MASK GENMASK(31, 30) +#define ID_P_MASK GENMASK(31, 29) enum rcar_i2c_type { I2C_RCAR_GEN1, @@ -345,7 +346,10 @@ static void rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv) rcar_i2c_write(priv, ICMSR, 0); rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START); } else { - rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START); + if (priv->flags & ID_P_REP_AFTER_RD) + priv->flags &= ~ID_P_REP_AFTER_RD; + else + 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); @@ -550,15 +554,15 @@ static void rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr) priv->pos++; } - /* - * If next received data is the _LAST_, go to STOP phase. Might be - * overwritten by REP START when setting up a new msg. Not elegant - * but the only stable sequence for REP START I have found so far. - * If you want to change this code, make sure sending one transfer with - * four messages (WR-RD-WR-RD) works! - */ - if (priv->pos + 1 >= msg->len) - rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); + /* If next received data is the _LAST_, go to new phase. */ + if (priv->pos + 1 == msg->len) { + if (priv->flags & ID_LAST_MSG) { + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); + } else { + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START); + priv->flags |= ID_P_REP_AFTER_RD; + } + } if (priv->pos == msg->len && !(priv->flags & ID_LAST_MSG)) rcar_i2c_next_msg(priv); @@ -626,9 +630,11 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr) struct rcar_i2c_priv *priv = ptr; u32 msr, val; - /* Clear START or STOP as soon as we can */ - val = rcar_i2c_read(priv, ICMCR); - rcar_i2c_write(priv, ICMCR, val & RCAR_BUS_MASK_DATA); + /* Clear START or STOP immediately, except for REPSTART after read */ + if (likely(!(priv->flags & ID_P_REP_AFTER_RD))) { + val = rcar_i2c_read(priv, ICMCR); + rcar_i2c_write(priv, ICMCR, val & RCAR_BUS_MASK_DATA); + } msr = rcar_i2c_read(priv, ICMSR); |