From b7f9bc73c7abc0de20081739fc990e92f5bccfc6 Mon Sep 17 00:00:00 2001 From: Balaji Rao Date: Thu, 29 Jan 2009 15:00:37 +0000 Subject: power: pcf50633: introduces battery charging current control Signed-off-by: Balaji Rao Signed-off-by: Paul Fertser --- drivers/power/pcf50633-charger.c | 73 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 68 insertions(+), 5 deletions(-) (limited to 'drivers/power') diff --git a/drivers/power/pcf50633-charger.c b/drivers/power/pcf50633-charger.c index 48e92c020f4..13f283991ff 100644 --- a/drivers/power/pcf50633-charger.c +++ b/drivers/power/pcf50633-charger.c @@ -48,16 +48,21 @@ int pcf50633_mbc_usb_curlim_set(struct pcf50633 *pcf, int ma) u8 bits; int charging_start = 1; u8 mbcs2, chgmod; + unsigned int mbcc5; - if (ma >= 1000) + if (ma >= 1000) { bits = PCF50633_MBCC7_USB_1000mA; - else if (ma >= 500) + ma = 1000; + } else if (ma >= 500) { bits = PCF50633_MBCC7_USB_500mA; - else if (ma >= 100) + ma = 500; + } else if (ma >= 100) { bits = PCF50633_MBCC7_USB_100mA; - else { + ma = 100; + } else { bits = PCF50633_MBCC7_USB_SUSPEND; charging_start = 0; + ma = 0; } ret = pcf50633_reg_set_bit_mask(pcf, PCF50633_REG_MBCC7, @@ -67,7 +72,24 @@ int pcf50633_mbc_usb_curlim_set(struct pcf50633 *pcf, int ma) else dev_info(pcf->dev, "usb curlim to %d mA\n", ma); - /* Manual charging start */ + /* + * We limit the charging current to be the USB current limit. + * The reason is that on pcf50633, when it enters PMU Standby mode, + * which it does when the device goes "off", the USB current limit + * reverts to the variant default. In at least one common case, that + * default is 500mA. By setting the charging current to be the same + * as the USB limit we set here before PMU standby, we enforce it only + * using the correct amount of current even when the USB current limit + * gets reset to the wrong thing + */ + + if (mbc->pcf->pdata->chg_ref_current_ma) { + mbcc5 = (ma << 8) / mbc->pcf->pdata->chg_ref_current_ma; + if (mbcc5 > 255) + mbcc5 = 255; + pcf50633_reg_write(mbc->pcf, PCF50633_REG_MBCC5, mbcc5); + } + mbcs2 = pcf50633_reg_read(pcf, PCF50633_REG_MBCS2); chgmod = (mbcs2 & PCF50633_MBCS2_MBC_MASK); @@ -157,9 +179,50 @@ static ssize_t set_usblim(struct device *dev, static DEVICE_ATTR(usb_curlim, S_IRUGO | S_IWUSR, show_usblim, set_usblim); +static ssize_t +show_chglim(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct pcf50633_mbc *mbc = dev_get_drvdata(dev); + u8 mbcc5 = pcf50633_reg_read(mbc->pcf, PCF50633_REG_MBCC5); + unsigned int ma; + + if (!mbc->pcf->pdata->chg_ref_current_ma) + return -ENODEV; + + ma = (mbc->pcf->pdata->chg_ref_current_ma * mbcc5) >> 8; + + return sprintf(buf, "%u\n", ma); +} + +static ssize_t set_chglim(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct pcf50633_mbc *mbc = dev_get_drvdata(dev); + unsigned long ma; + unsigned int mbcc5; + int ret; + + if (!mbc->pcf->pdata->chg_ref_current_ma) + return -ENODEV; + + ret = strict_strtoul(buf, 10, &ma); + if (ret) + return -EINVAL; + + mbcc5 = (ma << 8) / mbc->pcf->pdata->chg_ref_current_ma; + if (mbcc5 > 255) + mbcc5 = 255; + pcf50633_reg_write(mbc->pcf, PCF50633_REG_MBCC5, mbcc5); + + return count; +} + +static DEVICE_ATTR(chg_curlim, S_IRUGO | S_IWUSR, show_chglim, set_chglim); + static struct attribute *pcf50633_mbc_sysfs_entries[] = { &dev_attr_chgmode.attr, &dev_attr_usb_curlim.attr, + &dev_attr_chg_curlim.attr, NULL, }; -- cgit v1.2.3