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authorWolfram Sang <wsa+renesas@sang-engineering.com>2024-07-13 11:50:55 +0300
committerWolfram Sang <wsa+renesas@sang-engineering.com>2024-07-13 11:50:55 +0300
commit3fdd2d21f1c7f0203575b46d2b3fba81292992b6 (patch)
treeac9b66344d8e6866ec312fd766d5abf8d93bb520 /drivers/i2c
parent119736c7af442ab398dbb806865988c98ef60d46 (diff)
parentea5ea84c9d3570dc06e8fc5ee2273eaa584aa3ac (diff)
downloadlinux-3fdd2d21f1c7f0203575b46d2b3fba81292992b6.tar.xz
Merge tag 'i2c-host-fixes-6.10-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux into i2c/for-current
This tag includes three fixes for the Renesas R-Car driver: 1. Ensures the device is in a known state after probing. 2. Allows clearing the NO_RXDMA flag after a reset. 3. Forces a reset before any transfer on Gen3+ platforms to prevent disruption of the configuration during parallel transfers.
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-rcar.c27
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);