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SubjectRe: [PATCH] power: pcf50633: introduces battery charging current control
On Wed 2009-10-14 01:59:04, Paul Fertser wrote:
> From: Balaji Rao <balajirrao@openmoko.org>
>
> Signed-off-by: Balaji Rao <balajirrao@openmoko.org>
> Signed-off-by: Paul Fertser <fercerpav@gmail.com>
> ---
> drivers/power/pcf50633-charger.c | 73 ++++++++++++++++++++++++++++++++++---
> include/linux/mfd/pcf50633/core.h | 2 +
> 2 files changed, 70 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/power/pcf50633-charger.c b/drivers/power/pcf50633-charger.c
> index 48e92c0..13f2839 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,
> };
>
> diff --git a/include/linux/mfd/pcf50633/core.h b/include/linux/mfd/pcf50633/core.h
> index 9aba7b7..222dd90 100644
> --- a/include/linux/mfd/pcf50633/core.h
> +++ b/include/linux/mfd/pcf50633/core.h
> @@ -31,6 +31,8 @@ struct pcf50633_platform_data {
>
> int charging_restart_interval;
>
> + int chg_ref_current_ma;
> +
> /* Callbacks */
> void (*probe_done)(struct pcf50633 *);
> void (*mbc_event_callback)(struct pcf50633 *, int);

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html


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