Hi Rafael, On Thu, Jan 16, 2020 at 11:56 AM Bibby Hsieh <bibby.hsieh@xxxxxxxxxxxx> 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@xxxxxxxxxxxx> > --- > drivers/i2c/i2c-core-base.c | 81 +++++++++++++++++++++++++++++++++++++ > include/linux/i2c.h | 3 ++ > 2 files changed, 84 insertions(+) > I posted some comments in a separate reply [1] and Wolfram confirmed that he's fine with the approach [2]. Would you have some time to take a look from the PM point of view? Thanks. [1] https://patchwork.ozlabs.org/patch/1223991/#2350984 [2] https://patchwork.ozlabs.org/patch/1223991/#2351032 Please let me know if you want me to CC you directly on any of those replies. Best regards, Tomasz > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c > index 9333c865d4a9..9b9e96b094ca 100644 > --- a/drivers/i2c/i2c-core-base.c > +++ b/drivers/i2c/i2c-core-base.c > @@ -306,6 +306,7 @@ 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; > > @@ -371,6 +372,12 @@ static int i2c_device_probe(struct device *dev) > > dev_dbg(dev, "probe\n"); > > + status = regulator_enable(adap->bus_reg); > + 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; > @@ -407,6 +414,7 @@ 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; > > @@ -420,6 +428,8 @@ static int i2c_device_remove(struct device *dev) > } > > dev_pm_domain_detach(&client->dev, true); > + if (!pm_runtime_status_suspended(&adap->dev)) > + regulator_disable(adap->bus_reg); > > dev_pm_clear_wake_irq(&client->dev); > device_init_wakeup(&client->dev, false); > @@ -431,6 +441,71 @@ static int i2c_device_remove(struct device *dev) > return status; > } > > +#ifdef CONFIG_PM_SLEEP > +static int i2c_resume(struct device *dev) > +{ > + struct i2c_client *client = i2c_verify_client(dev); > + struct i2c_adapter *adap = client->adapter; > + int err; > + > + if (pm_runtime_status_suspended(&adap->dev)) { > + err = regulator_enable(adap->bus_reg); > + if (err) > + return err; > + } > + > + return pm_generic_resume(dev); > +} > + > +static int i2c_suspend(struct device *dev) > +{ > + struct i2c_client *client = i2c_verify_client(dev); > + struct i2c_adapter *adap = client->adapter; > + int err; > + > + if (!pm_runtime_status_suspended(&adap->dev)) { > + err = regulator_disable(adap->bus_reg); > + if (err) > + return err; > + } > + > + return pm_generic_suspend(dev); > +} > +#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_reg); > + if (err) > + return err; > + > + return pm_generic_runtime_resume(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(dev); > + if (err) > + return err; > + > + return regulator_disable(adap->bus_reg); > +} > +#endif > + > +static const struct dev_pm_ops i2c_device_pm = { > + SET_SYSTEM_SLEEP_PM_OPS(i2c_suspend, i2c_resume) > + 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); > @@ -488,6 +563,7 @@ 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); > > @@ -1351,6 +1427,11 @@ static int i2c_register_adapter(struct i2c_adapter *adap) > goto out_reg; > > dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); > + adap->bus_reg = devm_regulator_get(&adap->dev, "bus"); > + if (IS_ERR(adap->bus_reg)) { > + res = PTR_ERR(adap->bus_reg); > + goto out_reg; > + } > > pm_runtime_no_callbacks(&adap->dev); > pm_suspend_ignore_children(&adap->dev, true); > diff --git a/include/linux/i2c.h b/include/linux/i2c.h > index d2f786706657..833b81a680da 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 */ > @@ -330,6 +331,7 @@ struct i2c_client { > int init_irq; /* irq set at initialization */ > int irq; /* irq issued by device */ > struct list_head detected; > + > #if IS_ENABLED(CONFIG_I2C_SLAVE) > i2c_slave_cb_t slave_cb; /* callback for slave mode */ > #endif > @@ -723,6 +725,7 @@ struct i2c_adapter { > const struct i2c_adapter_quirks *quirks; > > struct irq_domain *host_notify_domain; > + struct regulator *bus_reg; > }; > #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) > > -- > 2.18.0
