Re: [PATCH] i2c: core: support bus regulator controlling in adapter
From: Hsin-Yi Wang
Date: Sun Mar 07 2021 - 23:40:14 EST
On Fri, Mar 5, 2021 at 6:20 PM Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx> wrote:
>
> From: Bibby Hsieh <bibby.hsieh@xxxxxxxxxxxx>
>
> 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>
> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
> ---
> This patch is squashed from following patch and tested on mt8183 device
> which has eeprom at24 client under i2c, so the fix in [2] is also
> verified.
> [1] https://patchwork.ozlabs.org/project/linux-i2c/cover/20200519072729.7268-1-bibby.hsieh@xxxxxxxxxxxx/
> [2] https://patchwork.ozlabs.org/project/linux-i2c/patch/20200522101327.13456-1-m.szyprowski@xxxxxxxxxxx/
> ---
Sent again with document rebased in v16 here:
https://patchwork.ozlabs.org/project/linux-i2c/cover/20210308043607.957156-1-hsinyi@xxxxxxxxxxxx/
> drivers/i2c/i2c-core-base.c | 93 +++++++++++++++++++++++++++++++++++++
> include/linux/i2c.h | 2 +
> 2 files changed, 95 insertions(+)
>
> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> index 63ebf722a424..667f4a4de7cc 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 +512,12 @@ 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;
> @@ -550,8 +558,10 @@ 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 +574,8 @@ 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);
> @@ -576,6 +588,80 @@ 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)
> + 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)
> + 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)
> + 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)
> + 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 +719,7 @@ 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);
>
> @@ -1446,6 +1533,12 @@ 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;
> + }
> +
> pm_runtime_no_callbacks(&adap->dev);
> pm_suspend_ignore_children(&adap->dev, true);
> pm_runtime_enable(&adap->dev);
> 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
>