From aca3c3546396b305fff79f09883cff48a908aac0 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 30 Jul 2015 10:11:24 +1000 Subject: [PATCH] twl4030_charger: allow max_current to be managed via sysfs. '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 Signed-off-by: NeilBrown Signed-off-by: Sebastian Reichel --- .../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..0331bba4605d --- /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 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 or 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 982675df21b7..b0a50adebfda 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); @@ -831,6 +896,11 @@ static int 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, @@ -855,6 +925,8 @@ 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); -- 2.20.1