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From 51374967e9c5be8b0bfa093d7c62e7093f1eff94 Mon Sep 17 00:00:00 2001
From: "Arun P. Mohanan" <arun.p.m@linux.intel.com>
Date: Wed, 27 Apr 2022 10:16:47 +0530
Subject: [PATCH] i2c: mux: Add mux deselect support on timeout
Add support to deselect the mux when there is a timeout.
The mux idle_state settings will be configured on startup. In case of
MCTP it is MUX_IDLE_DISCONNECT. But when there is a timeout, mux ends
up in connected position and the devices behind the mux will appear under
different muxes connected to the same bus. This change fix the same.
Signed-off-by: Arun P. Mohanan <arun.p.m@linux.intel.com>
---
drivers/i2c/i2c-mux.c | 15 ++++++++++-----
include/linux/i2c-mux.h | 1 +
2 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
index ce3c3ad3f129..abdfd7513df2 100644
--- a/drivers/i2c/i2c-mux.c
+++ b/drivers/i2c/i2c-mux.c
@@ -36,9 +36,11 @@ struct i2c_mux_priv {
u32 chan_id;
};
-static void i2c_mux_hold(struct i2c_mux_core *muxc, unsigned long timeout)
+static void i2c_mux_hold(struct i2c_mux_core *muxc, u32 chan_id,
+ unsigned long timeout)
{
mutex_lock(&muxc->hold_lock);
+ muxc->holder_chan_id = chan_id;
schedule_delayed_work(&muxc->unhold_work, timeout);
}
@@ -54,6 +56,9 @@ static void i2c_mux_unhold_work(struct work_struct *work)
struct i2c_mux_core *muxc = container_of(dwork, struct i2c_mux_core,
unhold_work);
+ if (muxc->deselect)
+ muxc->deselect(muxc, muxc->holder_chan_id);
+
mutex_unlock(&muxc->hold_lock);
}
@@ -74,7 +79,7 @@ static int __i2c_mux_master_xfer(struct i2c_adapter *adap,
(u16 *)msgs[num - 1].buf);
if (hold_msg == I2C_HOLD_MSG_SET) {
timeout = msecs_to_jiffies(*(u16 *)msgs[num - 1].buf);
- i2c_mux_hold(muxc, timeout);
+ i2c_mux_hold(muxc, priv->chan_id, timeout);
} else if (hold_msg == I2C_HOLD_MSG_NONE) {
mutex_lock(&muxc->hold_lock);
}
@@ -112,7 +117,7 @@ static int i2c_mux_master_xfer(struct i2c_adapter *adap,
(u16 *)msgs[num - 1].buf);
if (hold_msg == I2C_HOLD_MSG_SET) {
timeout = msecs_to_jiffies(*(u16 *)msgs[num - 1].buf);
- i2c_mux_hold(muxc, timeout);
+ i2c_mux_hold(muxc, priv->chan_id, timeout);
} else if (hold_msg == I2C_HOLD_MSG_NONE) {
mutex_lock(&muxc->hold_lock);
}
@@ -150,7 +155,7 @@ static int __i2c_mux_smbus_xfer(struct i2c_adapter *adap,
&data->word);
if (hold_msg == I2C_HOLD_MSG_SET) {
timeout = msecs_to_jiffies(data->word);
- i2c_mux_hold(muxc, timeout);
+ i2c_mux_hold(muxc, priv->chan_id, timeout);
} else if (hold_msg == I2C_HOLD_MSG_NONE) {
mutex_lock(&muxc->hold_lock);
}
@@ -189,7 +194,7 @@ static int i2c_mux_smbus_xfer(struct i2c_adapter *adap,
&data->word);
if (hold_msg == I2C_HOLD_MSG_SET) {
timeout = msecs_to_jiffies(data->word);
- i2c_mux_hold(muxc, timeout);
+ i2c_mux_hold(muxc, priv->chan_id, timeout);
} else if (hold_msg == I2C_HOLD_MSG_NONE) {
mutex_lock(&muxc->hold_lock);
}
diff --git a/include/linux/i2c-mux.h b/include/linux/i2c-mux.h
index 43c40680d8c5..3d2586062ccc 100644
--- a/include/linux/i2c-mux.h
+++ b/include/linux/i2c-mux.h
@@ -29,6 +29,7 @@ struct i2c_mux_core {
int (*deselect)(struct i2c_mux_core *, u32 chan_id);
struct mutex hold_lock; /* mutex for channel holding */
+ u32 holder_chan_id;
struct delayed_work unhold_work;
int num_adapters;
--
2.17.1
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