| Message ID | 20200428061813.27072-1-bibby.hsieh@mediatek.com |
|---|---|
| Headers | show |
| Series | add power control in i2c | expand |
On 28/04/2020 09:18, Bibby Hsieh wrote: > 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 get and enable bulk regulator in i2c adapter device. > > Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com> > --- > drivers/i2c/i2c-core-base.c | 82 +++++++++++++++++++++++++++++++++++++ > include/linux/i2c.h | 2 + > 2 files changed, 84 insertions(+) > > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c > index 5cc0b0ec5570..f81b42a4ed07 100644 > --- a/drivers/i2c/i2c-core-base.c > +++ b/drivers/i2c/i2c-core-base.c > @@ -313,6 +313,7 @@ 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 = client->adapter; > struct i2c_driver *driver; > int status; > > @@ -378,6 +379,12 @@ static int i2c_device_probe(struct device *dev) > > dev_dbg(dev, "probe\n"); > > + status = regulator_enable(adap->bus_regulator); > + if (status < 0) { > + dev_err(&adap->dev, "Failed to enable power regulator\n"); > + goto err_clear_wakeup_irq; > + } > + Sry, but this is confusing. What if there is separate regulators for I2C device and bus/adapter? I2C bus is transaction based and usually I2C bus drivers ensures that i2c bus is in proper state to perform transaction. While I2C devices can be enable, configured and function without actually interacting with I2C bus unless required (irq for example). With you change any I2C device will enable and keep bus regulator on all the time it's active even if there is no I2C interruptions. Following the problem description it seems - i2c bus driver should get regulator and ensure it's enabled for the duration of transaction(s) - i2c device should get its own regulator (or the same if shared) ensure it's enabled for the period device is active. > status = of_clk_set_defaults(dev->of_node, false); > if (status < 0) > goto err_clear_wakeup_irq; > @@ -414,6 +421,7 @@ static int i2c_device_probe(struct device *dev) > static int i2c_device_remove(struct device *dev) > { > struct i2c_client *client = i2c_verify_client(dev); > + struct i2c_adapter *adap = client->adapter; > struct i2c_driver *driver; > int status = 0; > > @@ -427,6 +435,8 @@ static int i2c_device_remove(struct device *dev) > } > > dev_pm_domain_detach(&client->dev, true); > + if (!pm_runtime_status_suspended(&client->dev)) > + regulator_disable(adap->bus_regulator); > > dev_pm_clear_wake_irq(&client->dev); > device_init_wakeup(&client->dev, false); > @@ -438,6 +448,72 @@ static int i2c_device_remove(struct device *dev) > return status; > } > > +#ifdef CONFIG_PM_SLEEP > +static int i2c_resume_early(struct device *dev) > +{ > + struct i2c_client *client = i2c_verify_client(dev); > + struct i2c_adapter *adap = client->adapter; > + int err; > + > + if (!pm_runtime_status_suspended(&client->dev)) { > + err = regulator_enable(adap->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); > + struct i2c_adapter *adap = client->adapter; > + int err; > + > + err = pm_generic_suspend_late(&client->dev); > + if (err) > + return err; > + > + if (!pm_runtime_status_suspended(&client->dev)) > + return regulator_disable(adap->bus_regulator); > + > + return err; > +} > +#endif Have you considered pm_runtime_force_suspend/pm_runtime_force_resume? > + > +#ifdef CONFIG_PM > +static int i2c_runtime_resume(struct device *dev) > +{ > + struct i2c_client *client = i2c_verify_client(dev); > + struct i2c_adapter *adap = client->adapter; > + int err; > + > + err = regulator_enable(adap->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); > + struct i2c_adapter *adap = client->adapter; > + int err; > + > + err = pm_generic_runtime_suspend(&client->dev); > + if (err) > + return err; > + > + return regulator_disable(adap->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); > @@ -495,6 +571,7 @@ 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); > > @@ -1333,6 +1410,11 @@ static int i2c_register_adapter(struct i2c_adapter *adap) > if (res) > goto out_reg; > > + adap->bus_regulator = devm_regulator_get(&adap->dev, "bus"); > + if (IS_ERR(adap->bus_regulator)) { > + res = PTR_ERR(adap->bus_regulator); > + goto out_reg; > + } > dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); > > pm_runtime_no_callbacks(&adap->dev); > diff --git a/include/linux/i2c.h b/include/linux/i2c.h > index 456fc17ecb1c..bc83af0d38d1 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) > >
On Tue, Apr 28, 2020 at 1:25 PM Grygorii Strashko <grygorii.strashko@ti.com> wrote: > > > > On 28/04/2020 09:18, Bibby Hsieh wrote: > > 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 get and enable bulk regulator in i2c adapter device. > > > > Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com> > > --- > > drivers/i2c/i2c-core-base.c | 82 +++++++++++++++++++++++++++++++++++++ > > include/linux/i2c.h | 2 + > > 2 files changed, 84 insertions(+) > > > > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c > > index 5cc0b0ec5570..f81b42a4ed07 100644 > > --- a/drivers/i2c/i2c-core-base.c > > +++ b/drivers/i2c/i2c-core-base.c > > @@ -313,6 +313,7 @@ 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 = client->adapter; > > struct i2c_driver *driver; > > int status; > > > > @@ -378,6 +379,12 @@ static int i2c_device_probe(struct device *dev) > > > > dev_dbg(dev, "probe\n"); > > > > + status = regulator_enable(adap->bus_regulator); > > + if (status < 0) { > > + dev_err(&adap->dev, "Failed to enable power regulator\n"); > > + goto err_clear_wakeup_irq; > > + } > > + > > Sry, but this is confusing. > What if there is separate regulators for I2C device and bus/adapter? > > I2C bus is transaction based and usually I2C bus drivers ensures that i2c bus is > in proper state to perform transaction. While I2C devices can be enable, configured and > function without actually interacting with I2C bus unless required (irq for example). > > With you change any I2C device will enable and keep bus regulator on all the time it's active > even if there is no I2C interruptions. The I2C SDA/SCL lines must stay high for all the time the bus is idle. The regulator in question here is exactly the regulator that drives the voltage rail the SDA/SCL lines are pulled up to and so it needs to be enabled all the time any slave device is active and expects the I2C bus to be in a valid state. > > Following the problem description it seems > - i2c bus driver should get regulator and ensure it's enabled for the duration of transaction(s) That's not necessary given the point below, because the slave driver must not trigger any I2C transactions when the slave device is not active. > - i2c device should get its own regulator (or the same if shared) ensure it's enabled for > the period device is active. This is a board design aspect and not specific to any particular I2C slave device, so slave drivers should not be aware of it. This patch exactly attempts to get this SDA/SCL regulator on behalf of the slave device. > > > > status = of_clk_set_defaults(dev->of_node, false); > > if (status < 0) > > goto err_clear_wakeup_irq; > > @@ -414,6 +421,7 @@ static int i2c_device_probe(struct device *dev) > > static int i2c_device_remove(struct device *dev) > > { > > struct i2c_client *client = i2c_verify_client(dev); > > + struct i2c_adapter *adap = client->adapter; > > struct i2c_driver *driver; > > int status = 0; > > > > @@ -427,6 +435,8 @@ static int i2c_device_remove(struct device *dev) > > } > > > > dev_pm_domain_detach(&client->dev, true); > > + if (!pm_runtime_status_suspended(&client->dev)) > > + regulator_disable(adap->bus_regulator); > > > > dev_pm_clear_wake_irq(&client->dev); > > device_init_wakeup(&client->dev, false); > > @@ -438,6 +448,72 @@ static int i2c_device_remove(struct device *dev) > > return status; > > } > > > > +#ifdef CONFIG_PM_SLEEP > > +static int i2c_resume_early(struct device *dev) > > +{ > > + struct i2c_client *client = i2c_verify_client(dev); > > + struct i2c_adapter *adap = client->adapter; > > + int err; > > + > > + if (!pm_runtime_status_suspended(&client->dev)) { > > + err = regulator_enable(adap->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); > > + struct i2c_adapter *adap = client->adapter; > > + int err; > > + > > + err = pm_generic_suspend_late(&client->dev); > > + if (err) > > + return err; > > + > > + if (!pm_runtime_status_suspended(&client->dev)) > > + return regulator_disable(adap->bus_regulator); > > + > > + return err; > > +} > > +#endif > > Have you considered pm_runtime_force_suspend/pm_runtime_force_resume? > > > + > > +#ifdef CONFIG_PM > > +static int i2c_runtime_resume(struct device *dev) > > +{ > > + struct i2c_client *client = i2c_verify_client(dev); > > + struct i2c_adapter *adap = client->adapter; > > + int err; > > + > > + err = regulator_enable(adap->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); > > + struct i2c_adapter *adap = client->adapter; > > + int err; > > + > > + err = pm_generic_runtime_suspend(&client->dev); > > + if (err) > > + return err; > > + > > + return regulator_disable(adap->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); > > @@ -495,6 +571,7 @@ 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); > > > > @@ -1333,6 +1410,11 @@ static int i2c_register_adapter(struct i2c_adapter *adap) > > if (res) > > goto out_reg; > > > > + adap->bus_regulator = devm_regulator_get(&adap->dev, "bus"); > > + if (IS_ERR(adap->bus_regulator)) { > > + res = PTR_ERR(adap->bus_regulator); > > + goto out_reg; > > + } > > dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); > > > > pm_runtime_no_callbacks(&adap->dev); > > diff --git a/include/linux/i2c.h b/include/linux/i2c.h > > index 456fc17ecb1c..bc83af0d38d1 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) > > > > > > -- > Best regards, > grygorii
On Tue, Apr 28, 2020 at 8:18 AM Bibby Hsieh <bibby.hsieh@mediatek.com> wrote: > > 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 get and enable bulk regulator in i2c adapter device. > > Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com> > --- > drivers/i2c/i2c-core-base.c | 82 +++++++++++++++++++++++++++++++++++++ > include/linux/i2c.h | 2 + > 2 files changed, 84 insertions(+) > Reviewed-by: Tomasz Figa <tfiga@chromium.org> Best regards, Tomasz > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c > index 5cc0b0ec5570..f81b42a4ed07 100644 > --- a/drivers/i2c/i2c-core-base.c > +++ b/drivers/i2c/i2c-core-base.c > @@ -313,6 +313,7 @@ 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 = client->adapter; > struct i2c_driver *driver; > int status; > > @@ -378,6 +379,12 @@ static int i2c_device_probe(struct device *dev) > > dev_dbg(dev, "probe\n"); > > + status = regulator_enable(adap->bus_regulator); > + if (status < 0) { > + dev_err(&adap->dev, "Failed to enable power regulator\n"); > + goto err_clear_wakeup_irq; > + } > + > status = of_clk_set_defaults(dev->of_node, false); > if (status < 0) > goto err_clear_wakeup_irq; > @@ -414,6 +421,7 @@ static int i2c_device_probe(struct device *dev) > static int i2c_device_remove(struct device *dev) > { > struct i2c_client *client = i2c_verify_client(dev); > + struct i2c_adapter *adap = client->adapter; > struct i2c_driver *driver; > int status = 0; > > @@ -427,6 +435,8 @@ static int i2c_device_remove(struct device *dev) > } > > dev_pm_domain_detach(&client->dev, true); > + if (!pm_runtime_status_suspended(&client->dev)) > + regulator_disable(adap->bus_regulator); > > dev_pm_clear_wake_irq(&client->dev); > device_init_wakeup(&client->dev, false); > @@ -438,6 +448,72 @@ static int i2c_device_remove(struct device *dev) > return status; > } > > +#ifdef CONFIG_PM_SLEEP > +static int i2c_resume_early(struct device *dev) > +{ > + struct i2c_client *client = i2c_verify_client(dev); > + struct i2c_adapter *adap = client->adapter; > + int err; > + > + if (!pm_runtime_status_suspended(&client->dev)) { > + err = regulator_enable(adap->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); > + struct i2c_adapter *adap = client->adapter; > + int err; > + > + err = pm_generic_suspend_late(&client->dev); > + if (err) > + return err; > + > + if (!pm_runtime_status_suspended(&client->dev)) > + return regulator_disable(adap->bus_regulator); > + > + return err; > +} > +#endif > + > +#ifdef CONFIG_PM > +static int i2c_runtime_resume(struct device *dev) > +{ > + struct i2c_client *client = i2c_verify_client(dev); > + struct i2c_adapter *adap = client->adapter; > + int err; > + > + err = regulator_enable(adap->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); > + struct i2c_adapter *adap = client->adapter; > + int err; > + > + err = pm_generic_runtime_suspend(&client->dev); > + if (err) > + return err; > + > + return regulator_disable(adap->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); > @@ -495,6 +571,7 @@ 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); > > @@ -1333,6 +1410,11 @@ static int i2c_register_adapter(struct i2c_adapter *adap) > if (res) > goto out_reg; > > + adap->bus_regulator = devm_regulator_get(&adap->dev, "bus"); > + if (IS_ERR(adap->bus_regulator)) { > + res = PTR_ERR(adap->bus_regulator); > + goto out_reg; > + } > dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); > > pm_runtime_no_callbacks(&adap->dev); > diff --git a/include/linux/i2c.h b/include/linux/i2c.h > index 456fc17ecb1c..bc83af0d38d1 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) > > -- > 2.18.0
On 28/04/2020 14:44, Tomasz Figa wrote: > On Tue, Apr 28, 2020 at 1:25 PM Grygorii Strashko > <grygorii.strashko@ti.com> wrote: >> >> >> >> On 28/04/2020 09:18, Bibby Hsieh wrote: >>> 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 get and enable bulk regulator in i2c adapter device. >>> >>> Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com> >>> --- >>> drivers/i2c/i2c-core-base.c | 82 +++++++++++++++++++++++++++++++++++++ >>> include/linux/i2c.h | 2 + >>> 2 files changed, 84 insertions(+) >>> >>> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c >>> index 5cc0b0ec5570..f81b42a4ed07 100644 >>> --- a/drivers/i2c/i2c-core-base.c >>> +++ b/drivers/i2c/i2c-core-base.c >>> @@ -313,6 +313,7 @@ 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 = client->adapter; >>> struct i2c_driver *driver; >>> int status; >>> >>> @@ -378,6 +379,12 @@ static int i2c_device_probe(struct device *dev) >>> >>> dev_dbg(dev, "probe\n"); >>> >>> + status = regulator_enable(adap->bus_regulator); >>> + if (status < 0) { >>> + dev_err(&adap->dev, "Failed to enable power regulator\n"); >>> + goto err_clear_wakeup_irq; >>> + } >>> + >> >> Sry, but this is confusing. >> What if there is separate regulators for I2C device and bus/adapter? >> >> I2C bus is transaction based and usually I2C bus drivers ensures that i2c bus is >> in proper state to perform transaction. While I2C devices can be enable, configured and >> function without actually interacting with I2C bus unless required (irq for example). >> >> With you change any I2C device will enable and keep bus regulator on all the time it's active >> even if there is no I2C interruptions. > > The I2C SDA/SCL lines must stay high for all the time the bus is idle. > The regulator in question here is exactly the regulator that drives > the voltage rail the SDA/SCL lines are pulled up to and so it needs to > be enabled all the time any slave device is active and expects the I2C > bus to be in a valid state. > >> >> Following the problem description it seems >> - i2c bus driver should get regulator and ensure it's enabled for the duration of transaction(s) > > That's not necessary given the point below, because the slave driver > must not trigger any I2C transactions when the slave device is not > active. > >> - i2c device should get its own regulator (or the same if shared) ensure it's enabled for >> the period device is active. > > This is a board design aspect and not specific to any particular I2C > slave device, so slave drivers should not be aware of it. This patch > exactly attempts to get this SDA/SCL regulator on behalf of the slave > device. Thank you for your explanation.
On Tue, Apr 28, 2020 at 02:18:13PM +0800, Bibby Hsieh wrote: > 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 get and enable bulk regulator in i2c adapter device. > > Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com> > --- > drivers/i2c/i2c-core-base.c | 82 +++++++++++++++++++++++++++++++++++++ > include/linux/i2c.h | 2 + > 2 files changed, 84 insertions(+) > > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c > index 5cc0b0ec5570..f81b42a4ed07 100644 > --- a/drivers/i2c/i2c-core-base.c > +++ b/drivers/i2c/i2c-core-base.c > @@ -313,6 +313,7 @@ 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 = client->adapter; You are accessing client before the NULL pointer check. > @@ -414,6 +421,7 @@ static int i2c_device_probe(struct device *dev) > static int i2c_device_remove(struct device *dev) > { > struct i2c_client *client = i2c_verify_client(dev); > + struct i2c_adapter *adap = client->adapter; Same here. > +static int i2c_suspend_late(struct device *dev) > +{ > + struct i2c_client *client = i2c_verify_client(dev); > + struct i2c_adapter *adap = client->adapter; > + int err; > + > + err = pm_generic_suspend_late(&client->dev); > + if (err) > + return err; > + > + if (!pm_runtime_status_suspended(&client->dev)) > + return regulator_disable(adap->bus_regulator); > + > + return err; Can be 'return 0'.
Hi, Wolfram, Thanks for the reviewing, I will sent next version for fixing up them. Bibby On Tue, 2020-05-19 at 08:59 +0200, Wolfram Sang wrote: > On Tue, Apr 28, 2020 at 02:18:13PM +0800, Bibby Hsieh wrote: > > 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 get and enable bulk regulator in i2c adapter device. > > > > Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com> > > --- > > drivers/i2c/i2c-core-base.c | 82 +++++++++++++++++++++++++++++++++++++ > > include/linux/i2c.h | 2 + > > 2 files changed, 84 insertions(+) > > > > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c > > index 5cc0b0ec5570..f81b42a4ed07 100644 > > --- a/drivers/i2c/i2c-core-base.c > > +++ b/drivers/i2c/i2c-core-base.c > > @@ -313,6 +313,7 @@ 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 = client->adapter; > > You are accessing client before the NULL pointer check. > > > > @@ -414,6 +421,7 @@ static int i2c_device_probe(struct device *dev) > > static int i2c_device_remove(struct device *dev) > > { > > struct i2c_client *client = i2c_verify_client(dev); > > + struct i2c_adapter *adap = client->adapter; > > Same here. > > > +static int i2c_suspend_late(struct device *dev) > > +{ > > + struct i2c_client *client = i2c_verify_client(dev); > > + struct i2c_adapter *adap = client->adapter; > > + int err; > > + > > + err = pm_generic_suspend_late(&client->dev); > > + if (err) > > + return err; > > + > > + if (!pm_runtime_status_suspended(&client->dev)) > > + return regulator_disable(adap->bus_regulator); > > + > > + return err; > > Can be 'return 0'. >
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 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 Changes since v7: - add binding describe supply property in i2c and at24. - move i2c bus supply control in i2c-core. - rebase onto v5.5-rc1 [... snip ...] Bibby Hsieh (2): dt-binding: i2c: add bus-supply property i2c: core: support bus regulator controlling in adapter Documentation/devicetree/bindings/i2c/i2c.txt | 3 + drivers/i2c/i2c-core-base.c | 82 +++++++++++++++++++ include/linux/i2c.h | 2 + 3 files changed, 87 insertions(+)