diff options
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-rcar.c | 27 |
1 files changed, 21 insertions, 6 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 828aa2ea0fe4..185a5d60f101 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -257,6 +257,14 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv) } } +static void rcar_i2c_reset_slave(struct rcar_i2c_priv *priv) +{ + rcar_i2c_write(priv, ICSIER, 0); + rcar_i2c_write(priv, ICSSR, 0); + rcar_i2c_write(priv, ICSCR, SDBS); + rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */ +} + static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv) { int ret; @@ -875,6 +883,10 @@ static int rcar_i2c_do_reset(struct rcar_i2c_priv *priv) { int ret; + /* Don't reset if a slave instance is currently running */ + if (priv->slave) + return -EISCONN; + ret = reset_control_reset(priv->rstc); if (ret) return ret; @@ -903,10 +915,10 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, /* Gen3+ needs a reset. That also allows RXDMA once */ if (priv->devtype >= I2C_RCAR_GEN3) { - priv->flags &= ~ID_P_NO_RXDMA; ret = rcar_i2c_do_reset(priv); if (ret) goto out; + priv->flags &= ~ID_P_NO_RXDMA; } rcar_i2c_init(priv); @@ -1033,11 +1045,8 @@ static int rcar_unreg_slave(struct i2c_client *slave) /* ensure no irq is running before clearing ptr */ disable_irq(priv->irq); - rcar_i2c_write(priv, ICSIER, 0); - rcar_i2c_write(priv, ICSSR, 0); + rcar_i2c_reset_slave(priv); enable_irq(priv->irq); - rcar_i2c_write(priv, ICSCR, SDBS); - rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */ priv->slave = NULL; @@ -1152,7 +1161,9 @@ static int rcar_i2c_probe(struct platform_device *pdev) goto out_pm_disable; } - rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */ + /* Bring hardware to known state */ + rcar_i2c_init(priv); + rcar_i2c_reset_slave(priv); if (priv->devtype < I2C_RCAR_GEN3) { irqflags |= IRQF_NO_THREAD; @@ -1168,6 +1179,7 @@ static int rcar_i2c_probe(struct platform_device *pdev) if (of_property_read_bool(dev->of_node, "smbus")) priv->flags |= ID_P_HOST_NOTIFY; + /* R-Car Gen3+ needs a reset before every transfer */ if (priv->devtype >= I2C_RCAR_GEN3) { priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); if (IS_ERR(priv->rstc)) { @@ -1178,6 +1190,9 @@ static int rcar_i2c_probe(struct platform_device *pdev) ret = reset_control_status(priv->rstc); if (ret < 0) goto out_pm_put; + + /* hard reset disturbs HostNotify local target, so disable it */ + priv->flags &= ~ID_P_HOST_NOTIFY; } ret = platform_get_irq(pdev, 0); |