Falco: Add support for bq24738 charger (and guess at battery).

This adds the BQ24738 smart battery charger, and a placeholder for the Falco
battery pack. I don't have either documentation or a battery to use to test,
so the battery pack stuff is just a guess (see crosbug.com/p/20142).

BUG=chrome-os-partner:20098
BRANCH=none
TEST=none

Well, if you like, from the EC console, run "charger". It should say
something like this:

  > charger
  Name  : bq24738
  Option: 1111100100010010 (0xf912)
  Man id: 0x0040
  Dev id: 0x000f
  V_batt:     0 (1024 - 19200,  16)
  I_batt:     0 ( 128 -  8128,  64)
  I_in  :  3968 ( 128 -  8064, 128)
  >

But since I don't have either a battery or a spec, I had to guess at the
battery configuration. To test the charger, we kind of need a battery.

Change-Id: I6e63d6b5aa8be4ba15e2c427d2e86364ef6251b3
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/58466

board/falco/board.c

@@ -127,11 +127,13 @@ const struct adc_t adc_channels[ADC_CH_COUNT] = {
 	{"ECTemp", LM4_ADC_SEQ0, -225, ADC_READ_MAX, 420,
 	 LM4_AIN_NONE, 0x0e /* TS0 | IE0 | END0 */, 0, 0},
 
-	/* HEY: need different equation for Falco */
-	/* Charger current is mapped from 0~4000mA to 0~1.6V.
-	 * And ADC maps 0~3.3V to ADC_READ_MAX.
+	/* IOUT == ICMNT is on PE3/AIN0 */
+	/* We have 0.01-ohm resistors, and IOUT is 20X the differential
+	 * voltage, so 1000mA ==> 200mV.
+	 * ADC returns 0x000-0xFFF, which maps to 0.0-3.3V (as configured).
+	 * mA = 1000 * ADC_VALUE / ADC_READ_MAX * 3300 / 200
 	 */
-	{"ChargerCurrent", LM4_ADC_SEQ1, 33 * 4000, ADC_READ_MAX * 16, 0,
+	{"ChargerCurrent", LM4_ADC_SEQ1, 33000, ADC_READ_MAX * 2, 0,
 	 LM4_AIN(0), 0x06 /* IE0 | END0 */, LM4_GPIO_E, (1<<3)},
 
 	/* AC Adapter ID voltage (mv) */

board/falco/board.h

@@ -15,9 +15,10 @@
 #define CONFIG_TASK_PROFILING
 
 /* Optional features */
-/*HEY #define CONFIG_SMART_BATTERY */
-/*HEY #define CONFIG_BATTERY_LINK */
-/*HEY #define CONFIG_CHARGER_BQ24725 */
+#define CONFIG_SMART_BATTERY
+#define CONFIG_BATTERY_FALCO
+#define CONFIG_CHARGER
+#define CONFIG_CHARGER_BQ24738
 #ifdef HAS_TASK_CHIPSET
 #define CONFIG_CHIPSET_X86_HASWELL
 #endif
@@ -141,6 +142,16 @@ enum gpio_signal {
 	GPIO_COUNT
 };
 
+/* Charger module */
+/* Set charger input current limit
+ * Note - this value should depend on external power adapter,
+ *        designed charging voltage, and the maximum power of
+ *        a running system.
+ */
+#define CONFIG_BQ24738_R_SNS 10 /* 10 mOhm charge sense resistor */
+#define CONFIG_BQ24738_R_AC  10 /* 10 mOhm input current sense resistor */
+#define CONFIG_CHARGER_INPUT_CURRENT 4032 /* mA, about half max */
+
 enum adc_channel {
 	/* EC internal die temperature in degrees K. */
 	ADC_CH_EC_TEMP = 0,

board/falco/ec.tasklist

@@ -19,7 +19,7 @@
 #define CONFIG_TASK_LIST \
 	TASK_ALWAYS(HOOKS, hook_task, NULL, TASK_STACK_SIZE) \
 	TASK_NOTEST(VBOOTHASH, vboot_hash_task, NULL, LARGER_TASK_STACK_SIZE) \
-	/*HEY  TASK_ALWAYS(CHARGER, charger_task, NULL, TASK_STACK_SIZE) */ \
+	TASK_ALWAYS(CHARGER, charger_task, NULL, TASK_STACK_SIZE) \
 	TASK_NOTEST(THERMAL, thermal_task, NULL, TASK_STACK_SIZE) \
 	TASK_NOTEST(CHIPSET, chipset_task, NULL, TASK_STACK_SIZE) \
 	TASK_NOTEST(KEYPROTO, keyboard_protocol_task, NULL, TASK_STACK_SIZE) \

common/battery_falco.c

@@ -0,0 +1,52 @@
+/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Battery pack vendor provided charging profile
+ */
+
+#include "battery_pack.h"
+
+/* FIXME: We need REAL values for all this stuff */
+static const struct battery_info info = {
+
+	.voltage_max    = 8400,
+	.voltage_normal = 7400,
+	.voltage_min    = 6000,
+
+	/*
+	 * Operational temperature range
+	 *   0 <= T_charge    <= 50 deg C
+	 * -20 <= T_discharge <= 60 deg C
+	 */
+	.temp_charge_min    = CELSIUS_TO_DECI_KELVIN(0),
+	.temp_charge_max    = CELSIUS_TO_DECI_KELVIN(50),
+	.temp_discharge_min = CELSIUS_TO_DECI_KELVIN(-20),
+	.temp_discharge_max = CELSIUS_TO_DECI_KELVIN(60),
+
+	/* Pre-charge values. */
+	.precharge_current  = 256,	/* mA */
+};
+
+const struct battery_info *battery_get_info(void)
+{
+	return &info;
+}
+
+/* FIXME: The smart battery should do the right thing - that's why it's
+ * called "smart". Do we really want to second-guess it? For now, let's not. */
+void battery_vendor_params(struct batt_params *batt)
+{
+#if 0
+	/* Limit charging voltage */
+	if (batt->desired_voltage > info.voltage_max)
+		batt->desired_voltage = info.voltage_max;
+
+	/* Don't charge if outside of allowable temperature range */
+	if (batt->temperature >= info.temp_charge_max ||
+	    batt->temperature <= info.temp_charge_min) {
+		batt->desired_voltage = 0;
+		batt->desired_current = 0;
+	}
+#endif
+}

common/build.mk

@@ -12,10 +12,12 @@ common-y+=gpio_common.o version.o printf.o queue.o
 common-$(CONFIG_BATTERY_BQ20Z453)+=battery_bq20z453.o
 common-$(CONFIG_BATTERY_LINK)+=battery_link.o
 common-$(CONFIG_BATTERY_SLIPPY)+=battery_slippy.o
+common-$(CONFIG_BATTERY_FALCO)+=battery_slippy.o
 common-$(CONFIG_BATTERY_SPRING)+=battery_spring.o
 common-$(CONFIG_CHARGER)+=charge_state.o battery_precharge.o charger_common.o
 common-$(CONFIG_CHARGER_BQ24725)+=charger_bq24725.o
 common-$(CONFIG_CHARGER_BQ24707A)+=charger_bq24707a.o
+common-$(CONFIG_CHARGER_BQ24738)+=charger_bq24738.o
 common-$(CONFIG_CHARGER_TPS65090)+=pmu_tps65090_charger.o
 common-$(CONFIG_CHIPSET_GAIA)+=gaia_power.o
 common-$(CONFIG_CHIPSET_X86_IVYBRIDGE)+=x86_power_ivybridge.o

common/charger_bq24738.c

@@ -0,0 +1,180 @@
+/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * TI bq24738 battery charger driver.
+ */
+
+#include "charger.h"
+#include "charger_bq24738.h"
+#include "console.h"
+#include "common.h"
+#include "i2c.h"
+#include "smart_battery.h"
+#include "util.h"
+
+/* Sense resistor configurations and macros */
+#define DEFAULT_SENSE_RESISTOR 10
+#define R_SNS CONFIG_BQ24738_R_SNS
+#define R_AC  CONFIG_BQ24738_R_AC
+#define REG_TO_CURRENT(REG, RS) ((REG) * DEFAULT_SENSE_RESISTOR / (RS))
+#define CURRENT_TO_REG(CUR, RS) ((CUR) * (RS) / DEFAULT_SENSE_RESISTOR)
+
+/* Charger infomation
+ * charge voltage bitmask: 0111 1111 1111 0000
+ * charge current bitmask: 0001 1111 1100 0000
+ * input current bitmask : 0000 0000 1000 0000
+ */
+static const struct charger_info bq24738_charger_info = {
+	.name         = "bq24738",
+	.voltage_max  = 19200,
+	.voltage_min  = 1024,
+	.voltage_step = 16,
+	.current_max  = REG_TO_CURRENT(8128, R_SNS),
+	.current_min  = REG_TO_CURRENT(128, R_SNS),
+	.current_step = REG_TO_CURRENT(64, R_SNS),
+	.input_current_max  = REG_TO_CURRENT(8064, R_AC),
+	.input_current_min  = REG_TO_CURRENT(128, R_AC),
+	.input_current_step = REG_TO_CURRENT(128, R_AC),
+};
+
+/* bq24738 specific interfaces */
+
+int charger_set_input_current(int input_current)
+{
+	return sbc_write(BQ24738_INPUT_CURRENT,
+			 CURRENT_TO_REG(input_current, R_AC));
+}
+
+int charger_get_input_current(int *input_current)
+{
+	int rv;
+	int reg;
+
+	rv = sbc_read(BQ24738_INPUT_CURRENT, &reg);
+	if (rv)
+		return rv;
+
+	*input_current = REG_TO_CURRENT(reg, R_AC);
+
+	return EC_SUCCESS;
+}
+
+int charger_manufacturer_id(int *id)
+{
+	return sbc_read(BQ24738_MANUFACTURE_ID, id);
+}
+
+int charger_device_id(int *id)
+{
+	return sbc_read(BQ24738_DEVICE_ID, id);
+}
+
+int charger_get_option(int *option)
+{
+	return sbc_read(BQ24738_CHARGE_OPTION, option);
+}
+
+int charger_set_option(int option)
+{
+	return sbc_write(BQ24738_CHARGE_OPTION, option);
+}
+
+/* Charger interfaces */
+
+const struct charger_info *charger_get_info(void)
+{
+	return &bq24738_charger_info;
+}
+
+int charger_get_status(int *status)
+{
+	int rv;
+	int option;
+
+	rv = charger_get_option(&option);
+	if (rv)
+		return rv;
+
+	/* Default status */
+	*status = CHARGER_LEVEL_2;
+
+	if (option & OPTION_CHARGE_INHIBIT)
+		*status |= CHARGER_CHARGE_INHIBITED;
+
+	return EC_SUCCESS;
+}
+
+int charger_set_mode(int mode)
+{
+	int rv;
+	int option;
+
+	rv = charger_get_option(&option);
+	if (rv)
+		return rv;
+
+	if (mode & CHARGE_FLAG_INHIBIT_CHARGE)
+		option |= OPTION_CHARGE_INHIBIT;
+	else
+		option &= ~OPTION_CHARGE_INHIBIT;
+	return charger_set_option(option);
+}
+
+int charger_get_current(int *current)
+{
+	int rv;
+	int reg;
+
+	rv = sbc_read(SB_CHARGING_CURRENT, &reg);
+	if (rv)
+		return rv;
+
+	*current = REG_TO_CURRENT(reg, R_SNS);
+	return EC_SUCCESS;
+}
+
+int charger_closest_current(int current)
+{
+	const struct charger_info * const info = charger_get_info();
+
+	/*
+	 * If the requested current is non-zero but below our minimum,
+	 * return the minimum.  See crosbug.com/p/8662.
+	 */
+	if (current > 0 && current < info->current_min)
+		return info->current_min;
+
+	/* Clip to max */
+	if (current > info->current_max)
+		return info->current_max;
+
+	/* Otherwise round down to nearest current step */
+	return current - (current % info->current_step);
+}
+
+int charger_set_current(int current)
+{
+	current = charger_closest_current(current);
+
+	return sbc_write(SB_CHARGING_CURRENT, CURRENT_TO_REG(current, R_SNS));
+}
+
+int charger_get_voltage(int *voltage)
+{
+	return sbc_read(SB_CHARGING_VOLTAGE, voltage);
+}
+
+int charger_set_voltage(int voltage)
+{
+	return sbc_write(SB_CHARGING_VOLTAGE, voltage);
+}
+
+/* Charging power state initialization */
+int charger_post_init(void)
+{
+	/* Accept POR defaults, plus... */
+
+	/* Set charger input current limit */
+	return charger_set_input_current(CONFIG_CHARGER_INPUT_CURRENT);
+}

include/charger_bq24738.h

@@ -0,0 +1,58 @@
+/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * TI bq24738 battery charger driver.
+ */
+
+#ifndef __CROS_EC_CHARGER_BQ24738_H
+#define __CROS_EC_CHARGER_BQ24738_H
+
+/* Chip specific commands */
+#define BQ24738_CHARGE_OPTION           0x12
+#define BQ24738_INPUT_CURRENT           0x3f
+#define BQ24738_MANUFACTURE_ID          0xfe
+#define BQ24738_DEVICE_ID               0xff
+
+/* ChargeOption 0x12 */
+#define OPTION_CHARGE_INHIBIT           (1 << 0)
+#define OPTION_ACOC_THRESHOLD           (1 << 1)
+#define OPTION_BOOST_MODE_STATE         (1 << 2)
+#define OPTION_BOOST_MODE_ENABLE        (1 << 3)
+#define OPTION_ACDET_STATE              (1 << 4)
+#define OPTION_IOUT_SELECTION           (1 << 5)
+#define OPTION_LEARN_ENABLE             (1 << 6)
+#define OPTION_IFAULT_LOW_THRESHOLD     (1 << 7)
+#define OPTION_IFAULT_HI_ENABLE         (1 << 8)
+#define OPTION_EMI_FREQ_ENABLE          (1 << 9)
+#define OPTION_EMI_FREQ_ADJ             (1 << 10)
+#define OPTION_BAT_DEPLETION_THRESHOLD  (3 << 11)
+#define OPTION_WATCHDOG_TIMER           (3 << 13)
+#define OPTION_ACPRES_DEGLITCH_TIME     (1 << 15)
+
+/* OPTION_ACOC_THRESHOLD */
+#define ACOC_THRESHOLD_DISABLE          (0 << 1)
+#define ACOC_THRESHOLD_133X             (1 << 1)
+
+/* OPTION_IFAULT_LOW_THRESHOLD */
+#define IFAULT_LOW_135MV_DEFAULT        (0 << 7)
+#define IFAULT_LOW_230MV                (1 << 7)
+
+/* OPTION_BAT_DEPLETION_THRESHOLD */
+#define FALLING_THRESHOLD_5919          (0 << 11)
+#define FALLING_THRESHOLD_6265          (1 << 11)
+#define FALLING_THRESHOLD_6655          (2 << 11)
+#define FALLING_THRESHOLD_7097_DEFAULT  (3 << 11)
+
+/* OPTION_WATCHDOG_TIMER */
+#define CHARGE_WATCHDOG_DISABLE         (0 << 13)
+#define CHARGE_WATCHDOG_44SEC           (1 << 13)
+#define CHARGE_WATCHDOG_88SEC           (2 << 13)
+#define CHARGE_WATCHDOG_175SEC_DEFAULT  (3 << 13)
+
+/* OPTION_ACPRES_DEGLITCH_TIME */
+#define ACPRES_DEGLITCH_150MS           (0 << 15)
+#define ACPRES_DEGLITCH_1300MS_DEFAULT  (1 << 15)
+
+#endif /* __CROS_EC_CHARGER_BQ24738_H */
+