Messages in this thread | | | Date | Mon, 4 Jul 2022 11:27:02 +0100 | From | Lee Jones <> | Subject | Re: [PATCH v3 1/2] mfd: da9062: enable being a system-power-controller |
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On Tue, 28 Jun 2022, Helmut Grohne wrote:
> The DA9062 can be the device used to power the CPU. In that case, it can > be used to power off the system. In the CONTROL_A register, the M_*_EN > bits must be zero for the corresponding *_EN bits to have an effect. We > zero them all to turn off the system. > > Signed-off-by: Helmut Grohne <helmut.grohne@intenta.de> > --- > drivers/mfd/da9062-core.c | 34 ++++++++++++++++++++++++++++++++++ > 1 file changed, 34 insertions(+) > > Compared to v2, this addresses the following concerns raised by Lee Jones: > * Drop unnecessary comment. > * Restructure da9062_power_off to avoid unnecessary assignments. > * Make power off failure message user friendly while still including > the error code for diagnostics. > > Lee Jones also questioned the utility of warning about pm_power_off already > being assigned: > > > Do we really mind/care? > > > > Is there anything we can do about it? > > > > Thus, do we really need to warn() about it? > > I do think this is useful, because it only happens when two nodes decalare > being a system-power-controller. It is a misconfiguration of your device tree > that is being warned here. Other drivers (e.g. rn5t618.c, act8865-regulator.c, > rtc-jz4740.c, and bcm2835_wdt.c) issue a similar warning. > > I note that Adam Thomson reviewed v2. Thank you. I did not include the > Reviewed-by, because noticeable code changed compared to what was reviewed. > > As pointed out by Adam Thomson, this version still uses regmap (and possibly > mutexes) in pm_power_off (with irqs disabled). This is a fundamental problem > shared with many other pm_power_off hooks. > > I've now included Rob Herring's Acked-by on the second patch as the rebase was > trivial. > > Helmut > diff --git a/drivers/mfd/da9062-core.c b/drivers/mfd/da9062-core.c > index 2774b2cbaea6..0083a2756f28 100644 > --- a/drivers/mfd/da9062-core.c > +++ b/drivers/mfd/da9062-core.c > @@ -620,6 +620,26 @@ static const struct of_device_id da9062_dt_ids[] = { > }; > MODULE_DEVICE_TABLE(of, da9062_dt_ids); > > +static struct i2c_client *da9062_i2c_client; > + > +static void da9062_power_off(void) > +{ > + int ret; > + > + ret = regmap_update_bits( > + ((struct > da9062*)i2c_get_clientdata(da9062_i2c_client))->regmap,
This is ugly. Please pull this out of the function args and separate the whole thing. No func()->attribute craziness please.
> + DA9062AA_CONTROL_A, > + DA9062AA_SYSTEM_EN_MASK | DA9062AA_POWER_EN_MASK | > + DA9062AA_POWER1_EN_MASK | DA9062AA_M_SYSTEM_EN_MASK | > + DA9062AA_M_POWER_EN_MASK | DA9062AA_M_POWER1_EN_MASK, > + 0 > + ); > + > + if (ret < 0) > + dev_err(&da9062_i2c_client->dev, > + "failed to power the system off (err=%d)\n", ret);
Either start with a uppercase char, or don't. Please be consistent.
> +} > + > static int da9062_i2c_probe(struct i2c_client *i2c, > const struct i2c_device_id *id) > { > @@ -720,6 +740,15 @@ static int da9062_i2c_probe(struct i2c_client *i2c, > return ret; > } > > + if (of_device_is_system_power_controller(i2c->dev.of_node)) { > + if (!pm_power_off) { > + da9062_i2c_client = i2c; > + pm_power_off = da9062_power_off; > + } else { > + dev_warn(&i2c->dev, "Poweroff callback already assigned\n"); > + } > + } > + > return ret; > } > > @@ -727,6 +756,11 @@ static int da9062_i2c_remove(struct i2c_client *i2c) > { > struct da9062 *chip = i2c_get_clientdata(i2c); > > + if (pm_power_off == da9062_power_off) > + pm_power_off = NULL; > + if (da9062_i2c_client) > + da9062_i2c_client = NULL; > + > mfd_remove_devices(chip->dev); > regmap_del_irq_chip(i2c->irq, chip->regmap_irq); >
-- Lee Jones [李琼斯] Principal Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog
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