diff mbox

[09/15] twl4030_charger: allow max_current to be managed via sysfs.

Message ID 20150224043351.4243.46323.stgit@notabene.brown (mailing list archive)
State New, archived
Headers show

Commit Message

NeilBrown Feb. 24, 2015, 4:33 a.m. UTC 
'max_current' sysfs attributes are created which allow the
max to be set.
Whenever a current source changes, the default is restored.
This will be followed by a uevent, so user-space can decide to
update again.

Signed-off-by: NeilBrown <neilb@suse.de>
---
 drivers/power/twl4030_charger.c |   76 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)



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Comments

Pavel Machek March 2, 2015, 9:05 p.m. UTC | #1 
On Tue 2015-02-24 15:33:52, NeilBrown wrote:
> 'max_current' sysfs attributes are created which allow the
> max to be set.
> Whenever a current source changes, the default is restored.
> This will be followed by a uevent, so user-space can decide to
> update again.

Does this need Documentation update?

> Signed-off-by: NeilBrown <neilb@suse.de>
> ---
>  drivers/power/twl4030_charger.c |   76 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 76 insertions(+)
> 
> diff --git a/drivers/power/twl4030_charger.c b/drivers/power/twl4030_charger.c
> index bfc9b808301e..b0242786d047 100644
> --- a/drivers/power/twl4030_charger.c
> +++ b/drivers/power/twl4030_charger.c
> @@ -527,6 +529,67 @@ static irqreturn_t twl4030_bci_interrupt(int irq, void *arg)
>  	return IRQ_HANDLED;
>  }
>  
> +/*
> + * sysfs max_current store
> + */

That's not exactly useful comment.

> +static ssize_t
> +twl4030_bci_max_current_store(struct device *dev, struct device_attribute *attr,
> +	const char *buf, size_t n)
> +{
> +	struct twl4030_bci *bci = dev_get_drvdata(dev->parent);
> +	int cur = 0;
> +	int status = 0;
> +	status = kstrtoint(buf, 10, &cur);
> +	if (status)
> +		return status;
> +	if (cur < 0)
> +		return -EINVAL;
> +	if (dev == bci->ac.dev) {
> +		if (bci->ac_cur == cur)
> +			return n;
> +		bci->ac_cur = cur;
> +	} else {
> +		if (bci->usb_cur == cur)
> +			return n;
> +		bci->usb_cur = cur;
> +	}
> +	twl4030_charger_update_current(bci);
> +	return (status == 0) ? n : status;
> +}

Uff. but we know that status == 0 at this point, no? Also... is
optimalization of not calling update_current() when nothing changed
worth it?

> +/*
> + * sysfs max_current show
> + */
> +static ssize_t twl4030_bci_max_current_show(struct device *dev,
> +	struct device_attribute *attr, char *buf)
> +{
> +	int status = 0;
> +	int cur = -1;
> +	u8 bcictl1;
> +	struct twl4030_bci *bci = dev_get_drvdata(dev->parent);
> +
> +	if (dev == bci->ac.dev) {
> +		if (!bci->ac_is_active)
> +			cur = bci->ac_cur;
> +	} else {
> +		if (bci->ac_is_active)
> +			cur = bci->usb_cur;
> +	}
> +	if (cur < 0) {
> +		cur = twl4030bci_read_adc_val(TWL4030_BCIIREF1);
> +		if (cur < 0)
> +			return cur;
> +		status = twl4030_bci_read(TWL4030_BCICTL1, &bcictl1);
> +		if (status < 0)
> +			return status;
> +		cur = regval2ua(cur, bcictl1 & TWL4030_CGAIN);
> +	}
> +	return scnprintf(buf, PAGE_SIZE, "%u\n", cur);
> +}

Is this in uA or mA? uA. Ok.

Acked-by: Pavel Machek <pavel@ucw.cz>
									Pavel
NeilBrown March 5, 2015, 6:26 a.m. UTC | #2 
On Mon, 2 Mar 2015 22:05:26 +0100 Pavel Machek <pavel@ucw.cz> wrote:

> On Tue 2015-02-24 15:33:52, NeilBrown wrote:
> > 'max_current' sysfs attributes are created which allow the
> > max to be set.
> > Whenever a current source changes, the default is restored.
> > This will be followed by a uevent, so user-space can decide to
> > update again.
> 
> Does this need Documentation update?

Oh all right... I've created the relevant documentation in Documentation/ABI.

It seems persistence pays off :-)


> 
> > Signed-off-by: NeilBrown <neilb@suse.de>
> > ---
> >  drivers/power/twl4030_charger.c |   76 +++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 76 insertions(+)
> > 
> > diff --git a/drivers/power/twl4030_charger.c b/drivers/power/twl4030_charger.c
> > index bfc9b808301e..b0242786d047 100644
> > --- a/drivers/power/twl4030_charger.c
> > +++ b/drivers/power/twl4030_charger.c
> > @@ -527,6 +529,67 @@ static irqreturn_t twl4030_bci_interrupt(int irq, void *arg)
> >  	return IRQ_HANDLED;
> >  }
> >  
> > +/*
> > + * sysfs max_current store
> > + */
> 
> That's not exactly useful comment.

Now:

 * Provide "max_current" attribute in sysfs.

> 
> > +static ssize_t
> > +twl4030_bci_max_current_store(struct device *dev, struct device_attribute *attr,
> > +	const char *buf, size_t n)
> > +{
> > +	struct twl4030_bci *bci = dev_get_drvdata(dev->parent);
> > +	int cur = 0;
> > +	int status = 0;
> > +	status = kstrtoint(buf, 10, &cur);
> > +	if (status)
> > +		return status;
> > +	if (cur < 0)
> > +		return -EINVAL;
> > +	if (dev == bci->ac.dev) {
> > +		if (bci->ac_cur == cur)
> > +			return n;
> > +		bci->ac_cur = cur;
> > +	} else {
> > +		if (bci->usb_cur == cur)
> > +			return n;
> > +		bci->usb_cur = cur;
> > +	}
> > +	twl4030_charger_update_current(bci);
> > +	return (status == 0) ? n : status;
> > +}
> 
> Uff. but we know that status == 0 at this point, no? 

Yes.  Fixed.

>                                                       Also... is
> optimalization of not calling update_current() when nothing changed
> worth it?

Probably not... and  code looks a lot nicer if I remove that.
So I have.


> 
> > +/*
> > + * sysfs max_current show
> > + */
> > +static ssize_t twl4030_bci_max_current_show(struct device *dev,
> > +	struct device_attribute *attr, char *buf)
> > +{
> > +	int status = 0;
> > +	int cur = -1;
> > +	u8 bcictl1;
> > +	struct twl4030_bci *bci = dev_get_drvdata(dev->parent);
> > +
> > +	if (dev == bci->ac.dev) {
> > +		if (!bci->ac_is_active)
> > +			cur = bci->ac_cur;
> > +	} else {
> > +		if (bci->ac_is_active)
> > +			cur = bci->usb_cur;
> > +	}
> > +	if (cur < 0) {
> > +		cur = twl4030bci_read_adc_val(TWL4030_BCIIREF1);
> > +		if (cur < 0)
> > +			return cur;
> > +		status = twl4030_bci_read(TWL4030_BCICTL1, &bcictl1);
> > +		if (status < 0)
> > +			return status;
> > +		cur = regval2ua(cur, bcictl1 & TWL4030_CGAIN);
> > +	}
> > +	return scnprintf(buf, PAGE_SIZE, "%u\n", cur);
> > +}
> 
> Is this in uA or mA? uA. Ok.

uA, now described in Documentation/ABI/testing/sysfs-class-power-twl4030

+What: /sys/class/power_supply/twl4030_ac/max_current
+      /sys/class/power_supply/twl4030_usb/max_current
+Description:
+       Read/Write limit on current which which may
+       be drawn from the ac (Accessory Charger) or
+       USB port.
+
+       Value is in micro-Amps.
+
+       Value is set automatically to an appropriate
+       value when a cable is plugged on unplugged.
+
+       Value can the set by writing to the attribute.
+       The change will only persist until the next
+       plug event.  These event are reported via udev.


> 
> Acked-by: Pavel Machek <pavel@ucw.cz>
> 									Pavel
> 

Thanks,
NeilBrown
Pavel Machek March 5, 2015, 8:17 a.m. UTC | #3 
> > Is this in uA or mA? uA. Ok.
> 
> uA, now described in Documentation/ABI/testing/sysfs-class-power-twl4030
> 
> +What: /sys/class/power_supply/twl4030_ac/max_current
> +      /sys/class/power_supply/twl4030_usb/max_current
> +Description:
> +       Read/Write limit on current which which may
> +       be drawn from the ac (Accessory Charger) or
> +       USB port.
> +
> +       Value is in micro-Amps.
> +
> +       Value is set automatically to an appropriate
> +       value when a cable is plugged on unplugged.
> +
> +       Value can the set by writing to the attribute.
> +       The change will only persist until the next
> +       plug event.  These event are reported via udev.

Thanks!
									Pavel
Sebastian Reichel March 7, 2015, 8:37 p.m. UTC | #4 
Hi,

On Thu, Mar 05, 2015 at 05:26:00PM +1100, NeilBrown wrote:
> [...]
> +What: /sys/class/power_supply/twl4030_ac/max_current
> +      /sys/class/power_supply/twl4030_usb/max_current
> +Description:
> +       Read/Write limit on current which which may
> +       be drawn from the ac (Accessory Charger) or
> +       USB port.
> +
> +       Value is in micro-Amps.
> +
> +       Value is set automatically to an appropriate
> +       value when a cable is plugged on unplugged.
                                        ^^
s/on/or

-- Sebastian
diff mbox

Patch

diff --git a/drivers/power/twl4030_charger.c b/drivers/power/twl4030_charger.c
index bfc9b808301e..b0242786d047 100644
--- a/drivers/power/twl4030_charger.c
+++ b/drivers/power/twl4030_charger.c
@@ -473,6 +473,8 @@  static irqreturn_t twl4030_charger_interrupt(int irq, void *arg)
 	struct twl4030_bci *bci = arg;
 
 	dev_dbg(bci->dev, "CHG_PRES irq\n");
+	/* reset current on each 'plug' event */
+	bci->ac_cur = 500000;
 	twl4030_charger_update_current(bci);
 	power_supply_changed(&bci->ac);
 	power_supply_changed(&bci->usb);
@@ -527,6 +529,67 @@  static irqreturn_t twl4030_bci_interrupt(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
+/*
+ * sysfs max_current store
+ */
+static ssize_t
+twl4030_bci_max_current_store(struct device *dev, struct device_attribute *attr,
+	const char *buf, size_t n)
+{
+	struct twl4030_bci *bci = dev_get_drvdata(dev->parent);
+	int cur = 0;
+	int status = 0;
+	status = kstrtoint(buf, 10, &cur);
+	if (status)
+		return status;
+	if (cur < 0)
+		return -EINVAL;
+	if (dev == bci->ac.dev) {
+		if (bci->ac_cur == cur)
+			return n;
+		bci->ac_cur = cur;
+	} else {
+		if (bci->usb_cur == cur)
+			return n;
+		bci->usb_cur = cur;
+	}
+	twl4030_charger_update_current(bci);
+	return (status == 0) ? n : status;
+}
+
+/*
+ * sysfs max_current show
+ */
+static ssize_t twl4030_bci_max_current_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	int status = 0;
+	int cur = -1;
+	u8 bcictl1;
+	struct twl4030_bci *bci = dev_get_drvdata(dev->parent);
+
+	if (dev == bci->ac.dev) {
+		if (!bci->ac_is_active)
+			cur = bci->ac_cur;
+	} else {
+		if (bci->ac_is_active)
+			cur = bci->usb_cur;
+	}
+	if (cur < 0) {
+		cur = twl4030bci_read_adc_val(TWL4030_BCIIREF1);
+		if (cur < 0)
+			return cur;
+		status = twl4030_bci_read(TWL4030_BCICTL1, &bcictl1);
+		if (status < 0)
+			return status;
+		cur = regval2ua(cur, bcictl1 & TWL4030_CGAIN);
+	}
+	return scnprintf(buf, PAGE_SIZE, "%u\n", cur);
+}
+
+static DEVICE_ATTR(max_current, 0644, twl4030_bci_max_current_show,
+			twl4030_bci_max_current_store);
+
 static void twl4030_bci_usb_work(struct work_struct *data)
 {
 	struct twl4030_bci *bci = container_of(data, struct twl4030_bci, work);
@@ -549,6 +612,12 @@  static int twl4030_bci_usb_ncb(struct notifier_block *nb, unsigned long val,
 
 	dev_dbg(bci->dev, "OTG notify %lu\n", val);
 
+	/* reset current on each 'plug' event */
+	if (allow_usb)
+		bci->usb_cur = 500000;
+	else
+		bci->usb_cur = 100000;
+
 	bci->event = val;
 	schedule_work(&bci->work);
 
@@ -809,6 +878,11 @@  static int __init twl4030_bci_probe(struct platform_device *pdev)
 		dev_warn(&pdev->dev, "failed to unmask interrupts: %d\n", ret);
 
 	twl4030_charger_update_current(bci);
+	if (device_create_file(bci->usb.dev, &dev_attr_max_current))
+		dev_warn(&pdev->dev, "could not create sysfs file\n");
+	if (device_create_file(bci->ac.dev, &dev_attr_max_current))
+		dev_warn(&pdev->dev, "could not create sysfs file\n");
+
 	twl4030_charger_enable_ac(true);
 	if (!IS_ERR_OR_NULL(bci->transceiver))
 		twl4030_bci_usb_ncb(&bci->usb_nb,
@@ -836,6 +910,8 @@  static int __exit twl4030_bci_remove(struct platform_device *pdev)
 	twl4030_charger_enable_usb(bci, false);
 	twl4030_charger_enable_backup(0, 0);
 
+	device_remove_file(bci->usb.dev, &dev_attr_max_current);
+	device_remove_file(bci->ac.dev, &dev_attr_max_current);
 	/* mask interrupts */
 	twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xff,
 			 TWL4030_INTERRUPTS_BCIIMR1A);