Re: [PATCH v8 3/4] misc: eeprom: at24: support pm_runtime control

[Bibby Hsieh <bibby.hsieh@mediatek.com>]

On Fri, 2019-12-13 at 10:02 +0100, Bartosz Golaszewski wrote:
> pt., 13 gru 2019 o 09:47 Bibby Hsieh <bibby.hsieh@mediatek.com> napisał(a):
> >
> > Although in the most platforms, the power of eeprom are alway
> > on, some platforms disable the eeprom power in order to meet
> > low power request. This patch add the pm_runtime ops to control
> > power to support all platforms.
> >
> > Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
> > ---
> >  drivers/misc/eeprom/at24.c | 40 ++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 40 insertions(+)
> >
> > diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
> > index 0681d5fdd538..06ae2cc32f79 100644
> > --- a/drivers/misc/eeprom/at24.c
> > +++ b/drivers/misc/eeprom/at24.c
> > @@ -22,6 +22,7 @@
> >  #include <linux/nvmem-provider.h>
> >  #include <linux/regmap.h>
> >  #include <linux/pm_runtime.h>
> > +#include <linux/regulator/consumer.h>
> >  #include <linux/gpio/consumer.h>
> >
> >  /* Address pointer is 16 bit. */
> > @@ -91,6 +92,7 @@ struct at24_data {
> >
> >         struct gpio_desc *wp_gpio;
> >
> > +       struct regulator *vcc_reg;
> >         /*
> >          * Some chips tie up multiple I2C addresses; dummy devices reserve
> >          * them for us, and we'll use them with SMBus calls.
> > @@ -662,6 +664,12 @@ static int at24_probe(struct i2c_client *client)
> >         at24->client[0].client = client;
> >         at24->client[0].regmap = regmap;
> >
> > +       at24->vcc_reg = devm_regulator_get(dev, "vcc");
> > +       if (IS_ERR(at24->vcc_reg)) {
> > +               dev_err(dev, "failed to get at24 VCC regulator\n");
> 
> The regulator core is quite verbose in its error messages when calling
> regulator_get() - you don't need to add yours here. Just return the
> error code.

Ok, will remove it.

> 
> > +               return PTR_ERR(at24->vcc_reg);
> > +       }
> > +
> >         at24->wp_gpio = devm_gpiod_get_optional(dev, "wp", GPIOD_OUT_HIGH);
> >         if (IS_ERR(at24->wp_gpio))
> >                 return PTR_ERR(at24->wp_gpio);
> > @@ -701,6 +709,12 @@ static int at24_probe(struct i2c_client *client)
> >
> >         i2c_set_clientdata(client, at24);
> >
> > +       err = regulator_enable(at24->vcc_reg);
> > +       if (err) {
> > +               dev_err(dev, "Failed to enable at24 vcc regulator\n");
> 
> Drop the at24 name - dev_err() will print the device name for you.
> 
Ok.
> > +               return err;
> > +       }
> > +
> >         /* enable runtime pm */
> >         pm_runtime_set_active(dev);
> >         pm_runtime_enable(dev);
> > @@ -713,6 +727,7 @@ static int at24_probe(struct i2c_client *client)
> >         pm_runtime_idle(dev);
> >         if (err) {
> >                 pm_runtime_disable(dev);
> > +               regulator_disable(at24->vcc_reg);
> >                 return -ENODEV;
> >         }
> >
> > @@ -729,14 +744,39 @@ static int at24_probe(struct i2c_client *client)
> >  static int at24_remove(struct i2c_client *client)
> >  {
> >         pm_runtime_disable(&client->dev);
> > +       if (pm_runtime_status_suspended(&client->dev))
> > +               regulator_disable(at24->vcc_reg);
> 
> Why didn't you fix the inverted logic here as I pointed out back in v6
> of this series?
> 
Sorry for missing it again...
I will add invert next version.

Bibby
> Bart
> 
> >         pm_runtime_set_suspended(&client->dev);
> >
> >         return 0;
> >  }
> >
> > +static int __maybe_unused at24_suspend(struct device *dev)
> > +{
> > +       struct i2c_client *client = to_i2c_client(dev);
> > +       struct at24_data *at24 = i2c_get_clientdata(client);
> > +
> > +       return regulator_disable(at24->vcc_reg);
> > +}
> > +
> > +static int __maybe_unused at24_resume(struct device *dev)
> > +{
> > +       struct i2c_client *client = to_i2c_client(dev);
> > +       struct at24_data *at24 = i2c_get_clientdata(client);
> > +
> > +       return regulator_enable(at24->vcc_reg);
> > +}
> > +
> > +static const struct dev_pm_ops at24_pm_ops = {
> > +       SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> > +                               pm_runtime_force_resume)
> > +       SET_RUNTIME_PM_OPS(at24_suspend, at24_resume, NULL)
> > +};
> > +
> >  static struct i2c_driver at24_driver = {
> >         .driver = {
> >                 .name = "at24",
> > +               .pm = &at24_pm_ops,
> >                 .of_match_table = at24_of_match,
> >                 .acpi_match_table = ACPI_PTR(at24_acpi_ids),
> >         },
> > --
> > 2.18.0