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Message-ID: <20150322232029.23789.13768.stgit@notabene.brown>
Date: Mon, 23 Mar 2015 10:20:29 +1100
From: NeilBrown <neil@...wn.name>
To: Sebastian Reichel <sre@...nel.org>
Cc: NeilBrown <neilb@...e.de>, linux-api@...r.kernel.org,
linux-kernel@...r.kernel.org,
GTA04 owners <gta04-owner@...delico.com>,
inux-pm@...r.kernel.org, Pavel Machek <pavel@....cz>,
linux-omap@...r.kernel.org, Lee Jones <lee.jones@...aro.org>
Subject: [PATCH 08/14] twl4030_charger: allow max_current to be managed via
sysfs.
From: NeilBrown <neilb@...e.de>
'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.
Acked-by: Pavel Machek <pavel@....cz>
Signed-off-by: NeilBrown <neilb@...e.de>
---
.../ABI/testing/sysfs-class-power-twl4030 | 15 ++++
drivers/power/twl4030_charger.c | 72 ++++++++++++++++++++
2 files changed, 87 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-class-power-twl4030
diff --git a/Documentation/ABI/testing/sysfs-class-power-twl4030 b/Documentation/ABI/testing/sysfs-class-power-twl4030
new file mode 100644
index 000000000000..06092209d851
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-power-twl4030
@@ -0,0 +1,15 @@
+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.
diff --git a/drivers/power/twl4030_charger.c b/drivers/power/twl4030_charger.c
index 37f2f40991ee..df031b0123d0 100644
--- a/drivers/power/twl4030_charger.c
+++ b/drivers/power/twl4030_charger.c
@@ -482,6 +482,8 @@ 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);
@@ -536,6 +538,63 @@ static irqreturn_t twl4030_bci_interrupt(int irq, void *arg)
return IRQ_HANDLED;
}
+/*
+ * 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)
+ bci->ac_cur = cur;
+ else
+ bci->usb_cur = cur;
+
+ twl4030_charger_update_current(bci);
+ return n;
+}
+
+/*
+ * 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);
@@ -558,6 +617,12 @@ 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);
@@ -818,6 +883,11 @@ 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,
@@ -842,6 +912,8 @@ 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);
--
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