As per Product Safety Engineering (PSE) specification for battery charging, the
battery characteristics and thereby the charging rates can vary on different
temperature zones. This patch introduces a PSE compliant charging algorithm with
maintenance charging support. The algorithm can be selected by the power supply
charging driver based on the type of the battery charging profile.
Signed-off-by: Jenny TC <jenny.tc@xxxxxxxxx>
---
drivers/power/Kconfig | 13 ++
drivers/power/Makefile | 1 +
drivers/power/charging_algo_pse.c | 204 ++++++++++++++++++++++++++++
include/linux/power/power_supply_charger.h | 48 +++++++
4 files changed, 266 insertions(+)
create mode 100644 drivers/power/charging_algo_pse.c
diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index f679f82..913ec36 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -22,6 +22,19 @@ config POWER_SUPPLY_CHARGER
drivers to keep the charging logic outside and the charger driver
just need to abstract the charger hardware.
+config POWER_SUPPLY_CHARGING_ALGO_PSE
+ bool "PSE compliant charging algorithm"
+ help
+ Say Y here to select Product Safety Engineering (PSE) compliant
+ charging algorithm. As per PSE standard the battery characteristics
+ and thereby the charging rates can vary on different temperature
+ zones. This config will enable PSE compliant charging algorithm with
+ maintenance charging support. At runtime the algorithm will be
+ selected by the psy charger driver based on the type of the battery
+ charging profile.
+
+ depends on POWER_SUPPLY_CHARGER
+
config PDA_POWER
tristate "Generic PDA/phone power driver"
depends on !S390
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index 405f0f4..77535fd 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_POWER_SUPPLY) += power_supply.o
obj-$(CONFIG_GENERIC_ADC_BATTERY) += generic-adc-battery.o
obj-$(CONFIG_POWER_SUPPLY_CHARGER) += power_supply_charger.o
+obj-$(CONFIG_POWER_SUPPLY_CHARGING_ALGO_PSE) += charging_algo_pse.o
obj-$(CONFIG_PDA_POWER) += pda_power.o
obj-$(CONFIG_APM_POWER) += apm_power.o
obj-$(CONFIG_MAX8925_POWER) += max8925_power.o
diff --git a/drivers/power/charging_algo_pse.c b/drivers/power/charging_algo_pse.c
new file mode 100644
index 0000000..a092e30
--- /dev/null
+++ b/drivers/power/charging_algo_pse.c
@@ -0,0 +1,204 @@
+/*
+ * Copyright (C) 2012 Intel Corporation
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * 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.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * Author: Jenny TC <jenny.tc@xxxxxxxxx>
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/power_supply.h>
+#include <linux/thermal.h>
+#include "power_supply.h"
+#include "power_supply_charger.h"
+
+/* 98% of CV is considered as voltage to detect Full */
+#define FULL_CV_MIN 98
+
+/*
+ * Offset to exit from maintenance charging. In maintenance charging
+ * if the volatge is less than the (maintenance_lower_threshold -
+ * MAINT_EXIT_OFFSET) then system can switch to normal charging
+ */
+
+#define MAINT_EXIT_OFFSET 50 /* mV */
+
+static int get_tempzone(struct psy_pse_chrg_prof *pse_mod_bprof,
+ int temp)
+{
+ int i = 0;
+ int temp_range_cnt = min_t(u16, pse_mod_bprof->temp_mon_ranges,
+ BATT_TEMP_NR_RNG);
+
+ if ((temp < pse_mod_bprof->temp_low_lim) ||
+ (temp > pse_mod_bprof->temp_mon_range[0].temp_up_lim))
+ return -EINVAL;
+
+ for (i = 0; i < temp_range_cnt; ++i)
+ if (temp > pse_mod_bprof->temp_mon_range[i].temp_up_lim)
+ break;
+ return i-1;
+}
+
+static inline bool __is_battery_full(long volt, long cur,
+ long iterm, unsigned long cv)
+{
+ pr_devel("%s:current=%ld pse_mod_bprof->chrg_term_mA =%ld voltage_now=%ld full_cond=%ld",
+ __func__, cur, iterm, volt * 100, (FULL_CV_MIN * cv));
+
+ return (cur > 0) && (cur <= iterm) &&
+ ((volt * 100) >= (FULL_CV_MIN * cv));
+
+}
+
+static inline bool is_battery_full(struct psy_batt_props bat_prop,
+ struct psy_pse_chrg_prof *pse_mod_bprof, unsigned long cv)
+{
+
+ int i;
+
+ /*
+ * Software full detection. Check the battery charge current to detect
+ * battery Full. The voltage also verified to avoid false charge
+ * full detection.
+ */
+ pr_devel("%s:current=%ld pse_mod_bprof->chrg_term_mA =%d bat_prop.voltage_now=%ld full_cond=%ld",
+ __func__, bat_prop.current_now, (pse_mod_bprof->chrg_term_mA),
+ bat_prop.voltage_now * 100, (FULL_CV_MIN * cv));
+
+ for (i = (MAX_CUR_VOLT_SAMPLES - 1); i >= 0; --i) {
+
+ if (!(__is_battery_full(bat_prop.voltage_now_cache[i],
+ bat_prop.current_now_cache[i],
+ pse_mod_bprof->chrg_term_mA, cv)))
+ return false;
+ }
+
+ return true;
+}
+
+static int pse_get_bat_thresholds(struct psy_batt_chrg_prof bprof,
+ struct psy_batt_thresholds *bat_thresh)
+{
+ struct psy_pse_chrg_prof *pse_mod_bprof =
+ (struct psy_pse_chrg_prof *) bprof.batt_prof;
+
+ if ((bprof.chrg_prof_type != PSY_CHRG_PROF_PSE) || (!pse_mod_bprof))
+ return -EINVAL;
+
+ bat_thresh->iterm = pse_mod_bprof->chrg_term_mA;
+ bat_thresh->temp_min = pse_mod_bprof->temp_low_lim;
+ bat_thresh->temp_max = pse_mod_bprof->temp_mon_range[0].temp_up_lim;
+
+ return 0;
+}
+
+static enum psy_algo_stat pse_get_next_cc_cv(struct psy_batt_props bat_prop,
+ struct psy_batt_chrg_prof bprof,
+ unsigned long *cc, unsigned long *cv)
+{
+ int tzone;
+ struct psy_pse_chrg_prof *pse_mod_bprof =
+ (struct psy_pse_chrg_prof *) bprof.batt_prof;
+ enum psy_algo_stat algo_stat = bat_prop.algo_stat;
+ int maint_exit_volt;
+
+ *cc = *cv = 0;
+
+ /*
+ * If STATUS is discharging, assume that charger is not connected.
+ * If charger is not connected, no need to take any action.
+ * If charge profile type is not PSY_CHRG_PROF_PSE or the charge profile
+ * is not present, no need to take any action.
+ */
+
+ pr_devel("%s:battery status = %ld algo_status=%d\n",
+ __func__, bat_prop.status, algo_stat);
+
+ if ((bprof.chrg_prof_type != PSY_CHRG_PROF_PSE) || (!pse_mod_bprof))
+ return PSY_ALGO_STAT_NOT_CHARGE;
+
+ tzone = get_tempzone(pse_mod_bprof, bat_prop.temperature);
+
+ if (tzone < 0)
+ return PSY_ALGO_STAT_NOT_CHARGE;
+
+ /*
+ * Change the algo status to not charging, if battery is
+ * not really charging or less than maintenance exit threshold.
+ * This way algorithm can switch to normal charging if current
+ * status is full/maintenance.
+ */
+ maint_exit_volt = pse_mod_bprof->
+ temp_mon_range[tzone].maint_chrg_vol_ll -
+ MAINT_EXIT_OFFSET;
+
+ if ((bat_prop.status == POWER_SUPPLY_STATUS_DISCHARGING) ||
+ (bat_prop.status == POWER_SUPPLY_STATUS_NOT_CHARGING) ||
+ bat_prop.voltage_now < maint_exit_volt) {
+
+ algo_stat = PSY_ALGO_STAT_NOT_CHARGE;
+
+ }
+
+ /* read cc and cv based on temperature and algorithm status */
+ if (algo_stat == PSY_ALGO_STAT_FULL ||
+ algo_stat == PSY_ALGO_STAT_MAINT) {
+
+ /*
+ * if status is full and voltage is lower than maintenance lower
+ * threshold change status to maintenance
+ */
+
+ if (algo_stat == PSY_ALGO_STAT_FULL && (bat_prop.voltage_now <=
+ pse_mod_bprof->temp_mon_range[tzone].maint_chrg_vol_ll))
+ algo_stat = PSY_ALGO_STAT_MAINT;
+
+ /* Read maintenance CC and CV */
+ if (algo_stat == PSY_ALGO_STAT_MAINT) {
+ *cv = pse_mod_bprof->temp_mon_range
+ [tzone].maint_chrg_vol_ul;
+ *cc = pse_mod_bprof->temp_mon_range
+ [tzone].maint_chrg_cur;
+ }
+ } else {
+ *cv = pse_mod_bprof->temp_mon_range[tzone].full_chrg_vol;
+ *cc = pse_mod_bprof->temp_mon_range[tzone].full_chrg_cur;
+ algo_stat = PSY_ALGO_STAT_CHARGE;
+ }
+
+ if (is_battery_full(bat_prop, pse_mod_bprof, *cv)) {
+ *cc = *cv = 0;
+ algo_stat = PSY_ALGO_STAT_FULL;
+ }
+
+ return algo_stat;
+}
+
+static int __init pse_algo_init(void)
+{
+ struct psy_charging_algo pse_algo;
+ pse_algo.chrg_prof_type = PSY_CHRG_PROF_PSE;
+ pse_algo.name = "pse_algo";
+ pse_algo.get_next_cc_cv = pse_get_next_cc_cv;
+ pse_algo.get_batt_thresholds = pse_get_bat_thresholds;
+ power_supply_register_charging_algo(&pse_algo);
+ return 0;
+}
+
+module_init(pse_algo_init);
diff --git a/include/linux/power/power_supply_charger.h b/include/linux/power/power_supply_charger.h
index 22a7b77..117b75b 100644
--- a/include/linux/power/power_supply_charger.h
+++ b/include/linux/power/power_supply_charger.h
@@ -77,8 +77,56 @@ enum {
enum psy_batt_chrg_prof_type {
PSY_CHRG_PROF_NONE = 0,
+ PSY_CHRG_PROF_PSE,
};
+/* Product Safety Engineering (PSE) compliant charging profile */
+
+/* Parameters defining the charging range */
+struct psy_ps_temp_chg_table {
+ /* upper temperature limit for each zone */
+ short int temp_up_lim; /* Degree Celsius */
+
+ /* charge current and voltage */
+ short int full_chrg_vol; /* mV */
+ short int full_chrg_cur; /* mA */
+
+ /*
+ * Maintenance charging thresholds.
+ * Maintenance charging voltage lower limit - Once battery hits full,
+ * charging will be resumed when battery voltage <= this voltage
+ */
+ short int maint_chrg_vol_ll; /* mV */
+
+ /* Charge current and voltage in maintenance charging mode */
+ short int maint_chrg_vol_ul; /* mV */
+ short int maint_chrg_cur; /* mA */
+} __packed;
+
+
+#define BATTID_STR_LEN 8
+#define BATT_TEMP_NR_RNG 6
+
+struct psy_pse_chrg_prof {
+ /* battery id */
+ char batt_id[BATTID_STR_LEN];
+ u16 battery_type; /* Defined as POWER_SUPPLY_TECHNOLOGY_* */
+ u16 capacity; /* mAh */
+ u16 voltage_max; /* mV */
+ /* charge termination current */
+ u16 chrg_term_mA;
+ /* Low battery level voltage */
+ u16 low_batt_mV;
+ /* upper and lower temperature limits on discharging */
+ s8 disch_temp_ul; /* Degree Celsius */
+ s8 disch_temp_ll; /* Degree Celsius */
+ /* number of temperature monitoring ranges */
+ u16 temp_mon_ranges;
+ struct psy_ps_temp_chg_table temp_mon_range[BATT_TEMP_NR_RNG];
+ /* lowest temperature supported */
+ s8 temp_low_lim;
+} __packed;
+
/* charging profile structure definition */
struct psy_batt_chrg_prof {
enum psy_batt_chrg_prof_type chrg_prof_type;
--
1.7.9.5
--
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