[PATCH v17 0/3] add power control in i2c

[PATCH v17 0/3] add power control in i2c

[Hsin-Yi Wang]

Although in the most platforms, the power of eeprom
and i2c are alway on, some platforms disable the
eeprom and i2c power in order to meet low power request.

This patch add the pm_runtime ops to control power to
support all platforms.

Changes since v16:
 - request regulator in device instead of in the core.
 - control regulator only if it's provided.

Changes since v15:
 - Squash the fix[1] for v15.
[1] https://patchwork.ozlabs.org/project/linux-i2c/patch/20200522101327.13456-1-m.szyprowski@samsung.com/

Changes since v14:
 - change the return value in normal condition
 - access the variable after NULL pointer checking
 - add ack tag

Changes since v13:
 - fixup some logic error

Changes since v12:
 - rebase onto v5.7-rc1
 - change the property description in binding

Changes since v11:
 - use suspend_late/resume_early instead of suspend/resume
 - rebase onto v5.6-rc1

Changes since v10:
 - fixup some worng codes

Changes since v9:
 - fixup build error
 - remove redundant code

Changes since v8:
 - fixup some wrong code
 - remove redundant message

        [... snip ...]


Bibby Hsieh (1):
  i2c: core: support bus regulator controlling in adapter

Hsin-Yi Wang (2):
  dt-binding: i2c: mt65xx: add vbus-supply property
  i2c: mediatek: mt65xx: add optional vbus-supply

 .../devicetree/bindings/i2c/i2c-mt65xx.txt    |  1 +
 drivers/i2c/busses/i2c-mt65xx.c               |  7 ++
 drivers/i2c/i2c-core-base.c                   | 88 +++++++++++++++++++
 include/linux/i2c.h                           |  2 +
 4 files changed, 98 insertions(+)

-- 
2.30.1.766.gb4fecdf3b7-goog

[PATCH v17 1/3] i2c: core: support bus regulator controlling in adapter

[Hsin-Yi Wang]

From: Bibby Hsieh <bibby.hsieh@mediatek.com>

Although in the most platforms, the bus power of i2c
are alway on, some platforms disable the i2c bus power
in order to meet low power request.

We can control bulk regulator if it is provided in i2c
adapter device.

Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
---
 drivers/i2c/i2c-core-base.c | 88 +++++++++++++++++++++++++++++++++++++
 include/linux/i2c.h         |  2 +
 2 files changed, 90 insertions(+)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 63ebf722a424..436e498528a8 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -439,12 +439,14 @@ static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client)
 static int i2c_device_probe(struct device *dev)
 {
 	struct i2c_client	*client = i2c_verify_client(dev);
+	struct i2c_adapter	*adap;
 	struct i2c_driver	*driver;
 	int status;
 
 	if (!client)
 		return 0;
 
+	adap = client->adapter;
 	client->irq = client->init_irq;
 
 	if (!client->irq) {
@@ -510,6 +512,14 @@ static int i2c_device_probe(struct device *dev)
 
 	dev_dbg(dev, "probe\n");
 
+	if (adap->bus_regulator) {
+		status = regulator_enable(adap->bus_regulator);
+		if (status < 0) {
+			dev_err(&adap->dev, "Failed to enable bus regulator\n");
+			goto err_clear_wakeup_irq;
+		}
+	}
+
 	status = of_clk_set_defaults(dev->of_node, false);
 	if (status < 0)
 		goto err_clear_wakeup_irq;
@@ -550,8 +560,10 @@ static int i2c_device_probe(struct device *dev)
 static int i2c_device_remove(struct device *dev)
 {
 	struct i2c_client	*client = to_i2c_client(dev);
+	struct i2c_adapter      *adap;
 	struct i2c_driver	*driver;
 
+	adap = client->adapter;
 	driver = to_i2c_driver(dev->driver);
 	if (driver->remove) {
 		int status;
@@ -564,6 +576,8 @@ static int i2c_device_remove(struct device *dev)
 	}
 
 	dev_pm_domain_detach(&client->dev, true);
+	if (!pm_runtime_status_suspended(&client->dev) && adap->bus_regulator)
+		regulator_disable(adap->bus_regulator);
 
 	dev_pm_clear_wake_irq(&client->dev);
 	device_init_wakeup(&client->dev, false);
@@ -576,6 +590,79 @@ static int i2c_device_remove(struct device *dev)
 	return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int i2c_resume_early(struct device *dev)
+{
+	struct i2c_client *client = i2c_verify_client(dev);
+	int err;
+
+	if (!client || !client->adapter->bus_regulator)
+		return 0;
+
+	if (!pm_runtime_status_suspended(&client->dev)) {
+		err = regulator_enable(client->adapter->bus_regulator);
+		if (err)
+			return err;
+	}
+
+	return pm_generic_resume_early(&client->dev);
+}
+
+static int i2c_suspend_late(struct device *dev)
+{
+	struct i2c_client *client = i2c_verify_client(dev);
+	int err;
+
+	if (!client || !client->adapter->bus_regulator)
+		return 0;
+
+	err = pm_generic_suspend_late(&client->dev);
+	if (err)
+		return err;
+
+	if (!pm_runtime_status_suspended(&client->dev))
+		return regulator_disable(client->adapter->bus_regulator);
+
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_PM
+static int i2c_runtime_resume(struct device *dev)
+{
+	struct i2c_client *client = i2c_verify_client(dev);
+	int err;
+
+	if (!client || !client->adapter->bus_regulator)
+		return 0;
+
+	err = regulator_enable(client->adapter->bus_regulator);
+	if (err)
+		return err;
+	return pm_generic_runtime_resume(&client->dev);
+}
+
+static int i2c_runtime_suspend(struct device *dev)
+{
+	struct i2c_client *client = i2c_verify_client(dev);
+	int err;
+
+	if (!client || !client->adapter->bus_regulator)
+		return 0;
+
+	err = pm_generic_runtime_suspend(&client->dev);
+	if (err)
+		return err;
+
+	return regulator_disable(client->adapter->bus_regulator);
+}
+#endif
+
+static const struct dev_pm_ops i2c_device_pm = {
+	SET_LATE_SYSTEM_SLEEP_PM_OPS(i2c_suspend_late, i2c_resume_early)
+	SET_RUNTIME_PM_OPS(i2c_runtime_suspend, i2c_runtime_resume, NULL)
+};
+
 static void i2c_device_shutdown(struct device *dev)
 {
 	struct i2c_client *client = i2c_verify_client(dev);
@@ -633,6 +720,7 @@ struct bus_type i2c_bus_type = {
 	.probe		= i2c_device_probe,
 	.remove		= i2c_device_remove,
 	.shutdown	= i2c_device_shutdown,
+	.pm		= &i2c_device_pm,
 };
 EXPORT_SYMBOL_GPL(i2c_bus_type);
 
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 56622658b215..ec87758d9f40 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -15,6 +15,7 @@
 #include <linux/device.h>	/* for struct device */
 #include <linux/sched.h>	/* for completion */
 #include <linux/mutex.h>
+#include <linux/regulator/consumer.h>
 #include <linux/rtmutex.h>
 #include <linux/irqdomain.h>		/* for Host Notify IRQ */
 #include <linux/of.h>		/* for struct device_node */
@@ -721,6 +722,7 @@ struct i2c_adapter {
 	const struct i2c_adapter_quirks *quirks;
 
 	struct irq_domain *host_notify_domain;
+	struct regulator *bus_regulator;
 };
 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
 
-- 
2.30.1.766.gb4fecdf3b7-goog

[PATCH v17 2/3] dt-binding: i2c: mt65xx: add vbus-supply property

[Hsin-Yi Wang]

Add vbus-supply property for mt65xx. The regulator can be passed into
core and turned off during suspend/sleep to reduce power consumption.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
---
 Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
index 7f0194fdd0cc..2c45647e9f0b 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
@@ -32,6 +32,7 @@ Optional properties:
   - mediatek,have-pmic: platform can control i2c form special pmic side.
     Only mt6589 and mt8135 support this feature.
   - mediatek,use-push-pull: IO config use push-pull mode.
+  - vbus-supply: phandle to the regulator that provides power to SCL/SDA.
 
 Example:
 
-- 
2.30.1.766.gb4fecdf3b7-goog

[PATCH v17 3/3] i2c: mediatek: mt65xx: add optional vbus-supply

[Hsin-Yi Wang]

Add vbus-supply which provides power to SCL/SDA. Pass this regulator
into core so it can be turned on/off for low power mode support.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
---
 drivers/i2c/busses/i2c-mt65xx.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 2ffd2f354d0a..82f2b6716005 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -1215,6 +1215,13 @@ static int mtk_i2c_probe(struct platform_device *pdev)
 	i2c->adap.quirks = i2c->dev_comp->quirks;
 	i2c->adap.timeout = 2 * HZ;
 	i2c->adap.retries = 1;
+	i2c->adap.bus_regulator = devm_regulator_get_optional(&pdev->dev, "vbus");
+	if (IS_ERR(i2c->adap.bus_regulator)) {
+		if (PTR_ERR(i2c->adap.bus_regulator) == -ENODEV)
+			i2c->adap.bus_regulator = NULL;
+		else
+			return PTR_ERR(i2c->adap.bus_regulator);
+	}
 
 	ret = mtk_i2c_parse_dt(pdev->dev.of_node, i2c);
 	if (ret)
-- 
2.30.1.766.gb4fecdf3b7-goog