From: Vincent Whitchurch <vincent.whitchurch@axis.com>
To: <wsa@kernel.org>
Cc: <kernel@axis.com>,
Vincent Whitchurch <vincent.whitchurch@axis.com>,
<linux-i2c@vger.kernel.org>, <devicetree@vger.kernel.org>,
<krzk+dt@kernel.org>, <robh+dt@kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: [PATCH 2/2] i2c: core: support no-detect property
Date: Tue, 5 Apr 2022 14:16:27 +0200 [thread overview]
Message-ID: <20220405121627.1560949-3-vincent.whitchurch@axis.com> (raw)
In-Reply-To: <20220405121627.1560949-1-vincent.whitchurch@axis.com>
If the devicetree specifies the no-detect property, we can avoid calling
drivers' detect callback and wasting time probing for devices which do
not exist.
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
---
drivers/i2c/i2c-core-base.c | 8 +++++++-
include/linux/i2c.h | 1 +
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index d43db2c3876e..d43025b84546 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1341,7 +1341,8 @@ static int i2c_do_add_adapter(struct i2c_driver *driver,
struct i2c_adapter *adap)
{
/* Detect supported devices on that bus, and instantiate them */
- i2c_detect(adap, driver);
+ if (adap->detect)
+ i2c_detect(adap, driver);
return 0;
}
@@ -1432,6 +1433,7 @@ EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify);
static int i2c_register_adapter(struct i2c_adapter *adap)
{
+ struct device_node *np = adap->dev.of_node;
int res = -EINVAL;
/* Can't register until after driver model init */
@@ -1502,6 +1504,10 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
"Failed to create compatibility class link\n");
#endif
+ adap->detect = true;
+ if (np && of_property_read_bool(np, "no-detect"))
+ adap->detect = false;
+
/* create pre-declared device nodes */
of_i2c_register_devices(adap);
i2c_acpi_install_space_handler(adap);
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index fbda5ada2afc..8fad5fe85685 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -728,6 +728,7 @@ struct i2c_adapter {
struct rt_mutex bus_lock;
struct rt_mutex mux_lock;
+ bool detect;
int timeout; /* in jiffies */
int retries;
struct device dev; /* the adapter device */
--
2.34.1
prev parent reply other threads:[~2022-04-06 0:57 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-05 12:16 [PATCH 0/2] i2c: Allow disabling auto detection via devicetree Vincent Whitchurch
2022-04-05 12:16 ` [PATCH 1/2] i2c: add binding to prevent device detection Vincent Whitchurch
2022-04-05 13:57 ` Krzysztof Kozlowski
2022-04-05 14:12 ` Vincent Whitchurch
2022-04-06 7:26 ` Krzysztof Kozlowski
2022-04-06 7:55 ` Krzysztof Kozlowski
2022-04-05 12:16 ` Vincent Whitchurch [this message]
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