changeset 225:09ea37852fd6

add function to convert Ichg ADC readings to mA
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 29 Apr 2021 05:13:09 +0000
parents bb1f572ac098
children 4f3bbe9515f8
files components/fchg src/cs/drivers/drv_app/fchg/fchg_api.h src/cs/drivers/drv_app/fchg/fchg_convert_mA.c
diffstat 3 files changed, 29 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/components/fchg	Wed Apr 28 05:44:07 2021 +0000
+++ b/components/fchg	Thu Apr 29 05:13:09 2021 +0000
@@ -36,6 +36,7 @@
 SRCDIR=$SRC/cs/drivers/drv_app/fchg
 
 cfile_plain $SRCDIR/fchg_api.c
+cfile_plain $SRCDIR/fchg_convert_mA.c
 cfile_plain $SRCDIR/fchg_default_batt.c
 cfile_plain $SRCDIR/fchg_env.c
 cfile_plain $SRCDIR/fchg_ffs_init.c
--- a/src/cs/drivers/drv_app/fchg/fchg_api.h	Wed Apr 28 05:44:07 2021 +0000
+++ b/src/cs/drivers/drv_app/fchg/fchg_api.h	Thu Apr 29 05:13:09 2021 +0000
@@ -27,5 +27,6 @@
 T_RV_RET fchg_user_charge_control(enum fchg_user_charge_ctrl);
 T_RV_RET fchg_get_current_state(struct fchg_user_state *);
 T_RV_RET fchg_register_event_handler(T_FCHG_EVENT_HANDLER);
+UINT16 fchg_convert_ichg_to_mA(UINT16 ichg);
 
 #endif	/* include guard */
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/cs/drivers/drv_app/fchg/fchg_convert_mA.c	Thu Apr 29 05:13:09 2021 +0000
@@ -0,0 +1,27 @@
+/*
+ * This module implements the fchg_convert_ichg_to_mA() function,
+ * converting charging current (Ichg) measurements from ADC units
+ * to human-friendly mA numbers.  In the phone hardware this current
+ * measurement is made with the aid of a current measurement resistor
+ * placed in the charging current path (the Iota chip's MADC actually
+ * measures the voltage across this resistor, between VCCS and VBATS
+ * terminals), and it just so happens that different phone designers
+ * have chosen different values for this current measurement resistor:
+ * Pirelli DP-L10 uses 0.20R, following TI's canon, whereas Mot C1xx
+ * phones use 0.15R.  Because of these different resistor values,
+ * the formula for converting ADC units to mA becomes target-dependent.
+ */
+
+#include "fchg/fchg_api.h"
+#include "fc-target.h"
+
+UINT16 fchg_convert_ichg_to_mA(UINT16 ichg)
+{
+#ifdef CONFIG_TARGET_COMPAL
+	/* formula for 0.15R */
+	return (ichg * 875 / 768);
+#else
+	/* formula for 0.20R */
+	return (ichg * 875 / 1024);
+#endif
+}