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 <[email protected]>
---
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,
+ 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);
+}
+
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);
--
2.30.2
Dipl.-Inf. Helmut Grohne
Research and Development
Application Engineering
Phone: +49 (371) 24354 0 ∙ Fax: +49 (371) 24354 020
[email protected] ∙ https://www.intenta.de
Intenta GmbH ∙ Ahornstraße 55 ∙ 09112 Chemnitz, Germany
Managing Director: Dr.-Ing. Basel Fardi ∙ VAT/USt-IdNr.: DE 275745394
Commercial register: HRB 26404 Amtsgericht Chemnitz
The DA9062 can be used to power off a system if it is appropriately
wired.
Signed-off-by: Helmut Grohne <[email protected]>
Acked-by: Rob Herring <[email protected]>
---
Documentation/devicetree/bindings/mfd/da9062.txt | 1 +
1 file changed, 1 insertion(+)
diff --git a/Documentation/devicetree/bindings/mfd/da9062.txt b/Documentation/devicetree/bindings/mfd/da9062.txt
index bab0d0e66cb3..4861c3ad97e9 100644
--- a/Documentation/devicetree/bindings/mfd/da9062.txt
+++ b/Documentation/devicetree/bindings/mfd/da9062.txt
@@ -41,6 +41,7 @@ further information on IRQ bindings.
Optional properties:
+- system-power-controller
- gpio-controller : Marks the device as a gpio controller.
- #gpio-cells : Should be two. The first cell is the pin number and the
second cell is used to specify the gpio polarity.
--
2.30.2
Dipl.-Inf. Helmut Grohne
Research and Development
Application Engineering
Phone: +49 (371) 24354 0 ∙ Fax: +49 (371) 24354 020
[email protected] ∙ https://www.intenta.de
Intenta GmbH ∙ Ahornstraße 55 ∙ 09112 Chemnitz, Germany
Managing Director: Dr.-Ing. Basel Fardi ∙ VAT/USt-IdNr.: DE 275745394
Commercial register: HRB 26404 Amtsgericht Chemnitz
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 <[email protected]>
> ---
> 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
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