On Tue, Apr 21, 2020 at 7:19 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 | 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..b3d15d6d449d 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)) {
Shouldn't this be !pm_runtime_status_suspended()? If the device was
suspended at system suspend time, we wouldn't have powered off the
regulator in our suspend_late callback, so we don't need to re-enable
it in resume_early.
Best regards,
Tomasz
