power: pm8xxx-ccadc: Add pm8xxx ccadc subdevice
Until now only the BMS system was using the ccadc so there was
no need to create a separate ccadc driver.
However we can run in a configuration with BMS disabled
and clients won't be able to read battery current via ccadc.
Separate the ccadc from the bms, this change in is preparation
to add a ccadc api to read the battery current.
Change-Id: Ib96b146d91d01d196df9291eb23432cd430db4d0
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
diff --git a/include/linux/mfd/pm8xxx/ccadc.h b/include/linux/mfd/pm8xxx/ccadc.h
new file mode 100644
index 0000000..6f6cb39
--- /dev/null
+++ b/include/linux/mfd/pm8xxx/ccadc.h
@@ -0,0 +1,100 @@
+/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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 __PMIC8XXX_CCADC_H__
+#define __PMIC8XXX_CCADC_H__
+
+#include <linux/mfd/pm8xxx/core.h>
+
+#define PM8XXX_CCADC_DEV_NAME "pm8xxx-ccadc"
+
+/**
+ * struct pm8xxx_ccadc_platform_data -
+ * @r_sense: sense resistor value in (mOhms)
+ */
+struct pm8xxx_ccadc_platform_data {
+ int r_sense;
+};
+
+#define CCADC_READING_RESOLUTION_N_V1 1085069
+#define CCADC_READING_RESOLUTION_D_V1 100000
+#define CCADC_READING_RESOLUTION_N_V2 542535
+#define CCADC_READING_RESOLUTION_D_V2 100000
+
+static s64 pm8xxx_ccadc_reading_to_microvolt_v1(s64 cc)
+{
+ return div_s64(cc * CCADC_READING_RESOLUTION_N_V1,
+ CCADC_READING_RESOLUTION_D_V1);
+}
+
+static s64 pm8xxx_ccadc_reading_to_microvolt_v2(s64 cc)
+{
+ return div_s64(cc * CCADC_READING_RESOLUTION_N_V2,
+ CCADC_READING_RESOLUTION_D_V2);
+}
+
+static inline s64 pm8xxx_ccadc_reading_to_microvolt(int revision, s64 cc)
+{
+ /*
+ * resolution (the value of a single bit) was changed after revision 2.0
+ * for more accurate readings
+ */
+ return (revision < PM8XXX_REVISION_8921_2p0) ?
+ pm8xxx_ccadc_reading_to_microvolt_v1((s64)cc) :
+ pm8xxx_ccadc_reading_to_microvolt_v2((s64)cc);
+}
+
+#if defined(CONFIG_PM8XXX_CCADC) || defined(CONFIG_PM8XXX_CCADC_MODULE)
+/**
+ * pm8xxx_cc_adjust_for_gain - the function to adjust the voltage read from
+ * ccadc for gain compensation
+ * @v: the voltage which needs to be gain compensated in microVolts
+ *
+ *
+ * RETURNS: gain compensated voltage
+ */
+s64 pm8xxx_cc_adjust_for_gain(s64 uv);
+
+/**
+ * pm8xxx_calib_ccadc - calibration for ccadc. This will calculate gain
+ * and offset and reprogram them in the appropriate
+ * registers
+ */
+void pm8xxx_calib_ccadc(void);
+
+/**
+ * pm8xxx_ccadc_get_battery_current - return the battery current based on vsense
+ * resitor in milliamperes
+ * @result: The pointer where the voltage will be updated. A -ve
+ * result means that the current is flowing in
+ * the battery - during battery charging
+ *
+ * RETURNS: Error code if there was a problem reading vsense, Zero otherwise
+ * The result won't be updated in case of an error.
+ *
+ */
+int pm8xxx_ccadc_get_battery_current(int *bat_current);
+#else
+static inline s64 pm8xxx_cc_adjust_for_gain(s64 uv)
+{
+ return -ENXIO;
+}
+static inline void pm8xxx_calib_ccadc(void)
+{
+}
+static inline int pm8xxx_ccadc_get_battery_current(int *bat_current)
+{
+ return -ENXIO;
+}
+#endif
+
+#endif /* __PMIC8XXX_CCADC_H__ */