Linux-ACPI Archive on lore.kernel.org
 help / color / Atom feed
From: Sakari Ailus <sakari.ailus@linux.intel.com>
To: linux-i2c@vger.kernel.org
Cc: Wolfram Sang <wsa@the-dreams.de>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	rajmohan.mani@intel.com, Tomasz Figa <tfiga@chromium.org>
Subject: [PATCH v3 1/5] i2c: Allow driver to manage the device's power state during probe
Date: Thu,  9 Jan 2020 17:45:25 +0200
Message-ID: <20200109154529.19484-2-sakari.ailus@linux.intel.com> (raw)
In-Reply-To: <20200109154529.19484-1-sakari.ailus@linux.intel.com>

Enable drivers to tell ACPI that there's no need to power on a device for
probe. Drivers should still perform this by themselves if there's a need
to. In some cases powering on the device during probe is undesirable, and
this change enables a driver to choose what fits best for it.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/i2c/i2c-core-base.c | 15 ++++++++++++---
 include/linux/i2c.h         |  3 +++
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 9f8dcd3f83850..7bf1699c9044d 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -303,6 +303,14 @@ static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client)
 	return irq > 0 ? irq : -ENXIO;
 }
 
+static bool probe_low_power(struct device *dev)
+{
+	struct i2c_driver *driver = to_i2c_driver(dev->driver);
+
+	return driver->probe_low_power &&
+		device_property_present(dev, "probe-low-power");
+}
+
 static int i2c_device_probe(struct device *dev)
 {
 	struct i2c_client	*client = i2c_verify_client(dev);
@@ -375,7 +383,8 @@ static int i2c_device_probe(struct device *dev)
 	if (status < 0)
 		goto err_clear_wakeup_irq;
 
-	status = dev_pm_domain_attach(&client->dev, true);
+	status = dev_pm_domain_attach(&client->dev,
+				      !probe_low_power(&client->dev));
 	if (status)
 		goto err_clear_wakeup_irq;
 
@@ -397,7 +406,7 @@ static int i2c_device_probe(struct device *dev)
 	return 0;
 
 err_detach_pm_domain:
-	dev_pm_domain_detach(&client->dev, true);
+	dev_pm_domain_detach(&client->dev, !probe_low_power(&client->dev));
 err_clear_wakeup_irq:
 	dev_pm_clear_wake_irq(&client->dev);
 	device_init_wakeup(&client->dev, false);
@@ -419,7 +428,7 @@ static int i2c_device_remove(struct device *dev)
 		status = driver->remove(client);
 	}
 
-	dev_pm_domain_detach(&client->dev, true);
+	dev_pm_domain_detach(&client->dev, !probe_low_power(&client->dev));
 
 	dev_pm_clear_wake_irq(&client->dev);
 	device_init_wakeup(&client->dev, false);
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 582ef05ec07ed..6d0d6af393c56 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -229,6 +229,8 @@ enum i2c_alert_protocol {
  * @address_list: The I2C addresses to probe (for detect)
  * @clients: List of detected clients we created (for i2c-core use only)
  * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping
+ * @probe_low_power: Let the driver manage the device's power state
+ *		     during probe and remove.
  *
  * The driver.owner field should be set to the module owner of this driver.
  * The driver.name field should be set to the name of this driver.
@@ -289,6 +291,7 @@ struct i2c_driver {
 	struct list_head clients;
 
 	bool disable_i2c_core_irq_mapping;
+	bool probe_low_power;
 };
 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
 
-- 
2.20.1


  reply index

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-09 15:45 [PATCH v3 0/5] Support running driver's probe for a device powered off Sakari Ailus
2020-01-09 15:45 ` Sakari Ailus [this message]
2020-01-09 15:45 ` [PATCH v3 2/5] ACPI: Add a convenience function to tell a device is suspended in probe Sakari Ailus
2020-01-13 10:41   ` Rafael J. Wysocki
2020-01-21  9:09     ` Sakari Ailus
2020-01-21 16:02       ` Rafael J. Wysocki
2020-01-09 15:45 ` [PATCH v3 3/5] ov5670: Support probe whilst the device is in a low power state Sakari Ailus
2020-01-09 15:45 ` [PATCH v3 4/5] media: i2c: imx319: Support probe while the device is off Sakari Ailus
2020-01-09 15:45 ` [PATCH v3 5/5] at24: Support probing while off Sakari Ailus
2020-01-10 11:16   ` Bartosz Golaszewski
2020-01-10 11:28     ` Sakari Ailus
2020-01-10 11:31       ` Bartosz Golaszewski

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200109154529.19484-2-sakari.ailus@linux.intel.com \
    --to=sakari.ailus@linux.intel.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-acpi@vger.kernel.org \
    --cc=linux-i2c@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rafael@kernel.org \
    --cc=rajmohan.mani@intel.com \
    --cc=tfiga@chromium.org \
    --cc=wsa@the-dreams.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-ACPI Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-acpi/0 linux-acpi/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-acpi linux-acpi/ https://lore.kernel.org/linux-acpi \
		linux-acpi@vger.kernel.org
	public-inbox-index linux-acpi

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-acpi


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git