drivers: misc: Implement USB fast charge mode

Signed-off-by: engstk <[email protected]>
Signed-off-by: Adithya R <[email protected]>

drivers/misc/Kconfig

@@ -619,12 +619,20 @@ config QCOM_LIQUID_DOCK
 	  This option enables support for the USB and Ethernet ports found on
 	  the docking station of various models of Qualcomm Technology's
 	  LiQUID Mobile Development Platforms.
+
 config UID_CPUTIME
 	tristate "Per-UID cpu time statistics"
 	depends on PROFILING
 	help
 	  Per UID based cpu time statistics exported to /proc/uid_cputime
 
+config FORCE_FAST_CHARGE
+	bool "Force faster charge rate for AC/USB"
+	default n
+	help
+	  This allows users to override default charge rate for both USB and AC
+	  charger input current
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"

drivers/misc/Makefile

@@ -68,3 +68,4 @@ obj-$(CONFIG_QPNP_MISC) += qpnp-misc.o
 obj-$(CONFIG_QCOM_LIQUID_DOCK)	+= qcom_liquid_dock.o
 obj-y				+= qcom/
 obj-$(CONFIG_UID_CPUTIME) 	+= uid_cputime.o
+obj-$(CONFIG_FORCE_FAST_CHARGE) += fastchg.o

drivers/misc/fastchg.c

@@ -0,0 +1,104 @@
+/*
+ * Author: Chad Froebel <[email protected]>
+ *
+ * Port to Nexus 5 : flar2 <[email protected]>
+ *
+ * Port to Osprey : engstk <[email protected]>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+/*
+ * Possible values for "force_fast_charge" are :
+ *
+ *   0 - Disabled (default)
+ *   1 - Force faster charge
+*/
+
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+#include <linux/fastchg.h>
+#include <linux/string.h>
+
+int force_fast_charge = 1;
+
+static int __init get_fastcharge_opt(char *ffc)
+{
+	if (strcmp(ffc, "0") == 0) {
+		force_fast_charge = 0;
+	} else if (strcmp(ffc, "1") == 0) {
+		force_fast_charge = 1;
+	} else {
+		force_fast_charge = 0;
+	}
+	return 1;
+}
+
+__setup("ffc=", get_fastcharge_opt);
+
+static ssize_t force_fast_charge_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+	size_t count = 0;
+	count += sprintf(buf, "%d\n", force_fast_charge);
+	return count;
+}
+
+static ssize_t force_fast_charge_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count)
+{
+	if (buf[0] >= '0' && buf[0] <= '1' && buf[1] == '\n')
+                if (force_fast_charge != buf[0] - '0')
+		        force_fast_charge = buf[0] - '0';
+
+	return count;
+}
+
+static struct kobj_attribute force_fast_charge_attribute =
+__ATTR(force_fast_charge, 0666, force_fast_charge_show, force_fast_charge_store);
+
+static struct attribute *force_fast_charge_attrs[] = {
+&force_fast_charge_attribute.attr,
+NULL,
+};
+
+static struct attribute_group force_fast_charge_attr_group = {
+.attrs = force_fast_charge_attrs,
+};
+
+/* Initialize fast charge sysfs folder */
+static struct kobject *force_fast_charge_kobj;
+
+int force_fast_charge_init(void)
+{
+	int force_fast_charge_retval;
+
+	force_fast_charge_kobj = kobject_create_and_add("fast_charge", kernel_kobj);
+	if (!force_fast_charge_kobj) {
+			return -ENOMEM;
+	}
+
+	force_fast_charge_retval = sysfs_create_group(force_fast_charge_kobj, &force_fast_charge_attr_group);
+
+	if (force_fast_charge_retval)
+		kobject_put(force_fast_charge_kobj);
+
+	if (force_fast_charge_retval)
+		kobject_put(force_fast_charge_kobj);
+
+	return (force_fast_charge_retval);
+}
+
+void force_fast_charge_exit(void)
+{
+	kobject_put(force_fast_charge_kobj);
+}
+
+module_init(force_fast_charge_init);
+module_exit(force_fast_charge_exit);

drivers/usb/phy/phy-msm-usb.c

@@ -52,6 +52,10 @@
 
 #include <linux/msm-bus.h>
 
+#ifdef CONFIG_FORCE_FAST_CHARGE
+#include <linux/fastchg.h>
+#endif
+
 #define MSM_USB_BASE	(motg->regs)
 #define MSM_USB_PHY_CSR_BASE (motg->phy_csr_regs)
 
@@ -1972,6 +1976,15 @@ static void msm_otg_notify_charger(struct msm_otg *motg, unsigned mA)
 	if (motg->cur_power == mA)
 		return;
 
+#ifdef CONFIG_FORCE_FAST_CHARGE
+	if (force_fast_charge > 0 && mA > 0) {
+		mA = IDEV_ACA_CHG_MAX;
+		pr_info("USB fast charging is ON\n");
+	} else {
+		pr_info("USB fast charging is OFF\n");
+	}
+#endif
+
 	dev_info(motg->phy.dev, "Avail curr from USB = %u\n", mA);
 	msm_otg_dbg_log_event(&motg->phy, "AVAIL CURR FROM USB",
 			mA, motg->chg_type);

include/linux/fastchg.h

@@ -0,0 +1,22 @@
+/*
+ * Author: Chad Froebel <[email protected]>
+ *
+ * Port to Osprey : engstk <[email protected]>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _LINUX_FASTCHG_H
+#define _LINUX_FASTCHG_H
+
+extern int force_fast_charge;
+
+#endif