force usb charge current

[Balaji Rao]

On Wed, Jan 28, 2009 at 07:57:55PM +0000, Andy Green wrote:
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> Hash: SHA1
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> Somebody in the thread at some point said:
>
> |> Balaji, what do you think?  It basically means allowing setting of MBCC5
> |> with a sys name like force_charging_limit_dangerous.
> |
> | Yea, AFAICS including this attribute is going to be harmless. Andy,
> | should I add it right away ?
>
> That'd be great, thanks.

Hi Andy,

Here it is.

Also in gta02-moredrivers-defconfig, NFSD is enabled and also
PHYSMAP_COMPAT which causes a backtrace during bootup. I think it was
disabled previously. There's a patch that fixes this is on
balaji-tracking along with the one below.

    pcf50633_charging_current_control.patch
    
    Introduces battery charging current control.
    
    Signed-off-by: Balaji Rao <balajirrao at openmoko.org>

diff --git a/arch/arm/mach-s3c2440/mach-gta02.c b/arch/arm/mach-s3c2440/mach-gta02.c
index 31759d8..d780128 100644
--- a/arch/arm/mach-s3c2440/mach-gta02.c
+++ b/arch/arm/mach-s3c2440/mach-gta02.c
@@ -640,6 +640,7 @@ struct pcf50633_platform_data gta02_pcf_pdata = {
 	.batteries = gta02_batteries,
 	.num_batteries = ARRAY_SIZE(gta02_batteries),
 	.charging_restart_interval = (900 * HZ),
+	.chg_ref_current_ma = 1000,
 
 	.reg_init_data = {
 		[PCF50633_REGULATOR_AUTO] = {
diff --git a/drivers/power/pcf50633-charger.c b/drivers/power/pcf50633-charger.c
index 1efd798..874caf6 100644
--- a/drivers/power/pcf50633-charger.c
+++ b/drivers/power/pcf50633-charger.c
@@ -156,9 +156,42 @@ 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;
+
+	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;
+	u8 mbcc5;
+	int ret;
+
+	ret = strict_strtoul(buf, 10, &ma);
+	if (ret)
+		return -EINVAL;
+
+	mbcc5 = (ma << 8) / mbc->pcf->pdata->chg_ref_current_ma;
+	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 b7a891b..af67b4e 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);