1. repo init -u git://review.sonyericsson.net/platform/manifest -b volatile-jb-mr1-yangtze
2. https://wiki.sonyericsson.net/androiki/CN3-II/Bringup_Trail_FC34  如何编译
3. https://wiki.sonyericsson.net/androiki/PLD_CM/Yangtze  如何编译和flash
4. https://wiki.sonyericsson.net/androiki/MIB_Tokyo/Rhine/Hardware_Watchdog_debugging

小技巧:
MISCTA 2473控制kernel log输出: 01 输出,00 无输出
repo sync [目录路径]  比如: kenel,system/vold
repo sync kernel 则只是同步kernel目录下的代码
grep  "ifelse" * -r  查找当前目录下(递归)所有文件中包含ifelse的内容
owner:xiaoguang2.lu@sonymobile.com status:merged  //查找谁提交并且已经merged的gerrit
printk("func = %pf",func)可打印函数名称出来


充电缩写语:(acronym)
FSM: Finite State Machine
CC: Coulcomb Counter
FCC: Full Charge Capacity
OCV: Open Circuit Voltage
PMIC: Power Management IC
PC: Percentage Charge
RC: Remaining Charge
SOC: State of Charge
RUC: Remaining Usable Charge
UUC: Unusable Charge

一、DTS 学习
1. kernel/arch/arm/boot/dts 目录下包含所有的dts.
    a. board , msm8226.dtsi
    b. pmic, msm-pm8226.dtsi
2. kernel/Androidkernel.mk;  Android makefile to build kernel as a part of Android Build
3. kernel/arch/arm/configs 目录下保存对应的config定义, CONFIG_XXXXXX
4. 可参考 jb-mr1-rhine/kernel/arch/arm/boot/dts/msm8974-rhine_togari_row.dtsi

二、LCD Porting
1. http://review.sonyericsson.net/#/c/508903

三、Charger bringup
1. 和battery and hw guys 确定相关 硬件参数
2. http://review.sonyericsson.net/#/c/516297/
3. kernel 发送给battery_logging的uevent格式?
    power_supply_uevent@kernel/drivers/power/power_supply_sysfs.c 该函数添加发送的信息到uevent
    ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->name); //psy->name="battery"
    for (j = 0; j < psy->num_properties; j++) {
        attr = &power_supply_attrs[psy->properties[j]]; //得到对应的power supply attr,
        attrname = kstruprdup(attr->attr.name, GFP_KERNEL);//会把属性名字转成大写,比如“status”->"STATUS"
        ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf); //增加该属性的信息到uevent buffer中
    }
    
    qpnp_charger_probe@kernel/drivers/power/qpnp-charger.c中会定义"battery"的properties = msm_batt_power_props
    static enum power_supply_property msm_batt_power_props[] = { //对应power_supply_attrs[]@kernel/drivers/power/power_supply_sysfs.c
        POWER_SUPPLY_PROP_CHARGING_ENABLED,             //表示这些属性是被battery psy所需要的属性,具体如何得到可查看    
        POWER_SUPPLY_PROP_STATUS,               //qpnp_batt_power_get_property 函数
        POWER_SUPPLY_PROP_CHARGE_TYPE,                    //这些属性会添加到/sys/class/power_supply/battery    
        POWER_SUPPLY_PROP_HEALTH,        
        POWER_SUPPLY_PROP_PRESENT,        
        POWER_SUPPLY_PROP_TECHNOLOGY,        
        POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
        POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,        
        POWER_SUPPLY_PROP_CAPACITY,        
        POWER_SUPPLY_PROP_CURRENT_NOW,        
        POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
        POWER_SUPPLY_PROP_TEMP,            
        POWER_SUPPLY_PROP_SYSTEM_TEMP_LEVEL,
    };
    
    static struct device_attribute power_supply_attrs[] = {
        /* Properties of type `int' */
        POWER_SUPPLY_ATTR(status),  //表示attr.name = "status"
        POWER_SUPPLY_ATTR(charge_type),
        ...
    }
4. parse_uevent@vendor/semc/hardware/power/charge-log/battery_logging/battery_logging.c会分析从kernel传上来的power uevent格式
    发送该uevent的path  '\0'
    POWER_SUPPLY_NAME=battery '\0'
    POWER_SUPPLY_CHARGING_ENABLE=%d '\0'
    POWER_SUPPLY_CHARGING_STATUS=%d '\0'    
    ...

5. 顺便分析下UEvent如何传递给user space?
    a. @kernel/drivers/power/qpnp-charger.c中只要有任何关于charger的变化,比如charger的各种irq handler
    b. @kernel/drivers/power/qpnp-bms.c中calculate_soc_from_voltage和calculate_state_of_charge
    c. @kernel/arch/arm/boot/dts/msm-pm8226.dtsi中有pm8226_bms的device定义,msm8226-cn3ii.dtsi中有pm8226_bms的定义补充
        其中没有 qcom,use-voltage-soc 的定义所以chip->use_voltage_soc=false, 也就是只用calculate_state_of_charge计算soc
        顺便chip->use_external_rsense=true,表示用外部的rsense.
    d. @kernel/driver/power/power_supply_core.c中的power_supply_changed会被以上内容调用
        schedule_work(&psy->changed_work);
    e. power_supply_changed_work@kernel/driver/power/power_supply_core.c
        kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE); //action=KOBJ_CHANGE
    f. kobject_uevent_env@kernel/lib/kobject_uevent.c
        static const char *kobject_actions[] = {
            [KOBJ_ADD] =        "add",
            [KOBJ_REMOVE] =        "remove",
            [KOBJ_CHANGE] =        "change",
            [KOBJ_MOVE] =        "move",
            [KOBJ_ONLINE] =        "online",
            [KOBJ_OFFLINE] =    "offline",
        };
        以下为添加到uevent buffer中发送的内容
        /* default keys */
        retval = add_uevent_var(env, "ACTION=%s", action_string);//action_string="change"        
        retval = add_uevent_var(env, "DEVPATH=%s", devpath);//devpath = kobject_get_path(kobj, GFP_KERNEL);
        retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem);//也就是uevent 的name
        retval = uevent_ops->uevent(kset, kobj, env); //会调用到power_supply_uevent@kernel/drivers/power/power_supply_sysfs.c
                                //也就是会添加具体的power battery信息到uevent buffer中了
        retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum); //增加uevent发送的计数,
                    //KERNEL_ATTR_RO(uevent_seqnum); 用cat sys/kernel/uevent_seqnum 可以查看
        CONFIG_NET=y被定义,以下代码是发送uevent到userspace 的关键代码
        #if defined(CONFIG_NET)
            /* send netlink message */
            list_for_each_entry(ue_sk, &uevent_sock_list, list) { //uevent_net_init会初始化一个uevent_sock,也只有一个
                if (!netlink_has_listeners(uevent_sock, 1))
                    continue;

                /* allocate message with the maximum possible size */
                len = strlen(action_string) + strlen(devpath) + 2;
                skb = alloc_skb(len + env->buflen, GFP_KERNEL);
                if (skb) {
                    retval = netlink_broadcast_filtered(uevent_sock, skb,
                                        0, 1, GFP_KERNEL,
                                        kobj_bcast_filter,
                                        kobj);
                } else
                    retval = -ENOMEM;
            }
        #endif
6. Battery充满的识别  
    1). @kernel/arch/arm/boot/dts/msm-pm8226.dtsi和msm8226-cn3ii.dtsi
    qcom,chg-chgr@1000 {
    status = "disabled";
    reg = <0x1000 0x100>;
    interrupts =    <0x0 0x10 0x0>,
            <0x0 0x10 0x1>,
            <0x0 0x10 0x2>,
            <0x0 0x10 0x3>,
            <0x0 0x10 0x4>,
            <0x0 0x10 0x5>,
            <0x0 0x10 0x6>,
            <0x0 0x10 0x7>;  //具体的含义?

    interrupt-names =    "vbat-det-lo",
                "vbat-det-hi",
                "chgwdog",
                "state-change",
                "trkl-chg-on",
                "fast-chg-on",
                "chg-failed",
                "chg-done";
    };
    2). qpnp_chg_hwinit@kernel/drivers/power
    chip->chg_done_irq = spmi_get_irq_byname(chip->spmi,spmi_resource, "chg-done");
       如何触发"chg-done"这个interrupt?     
    3).获取当前充电状态
        rc = qpnp_chg_read(chip, &chgr_sts,INT_RT_STS(chip->chgr_base), 1);    
        如果chgr_sts&CHG_DONE_IRQ == 1则表示充电完成
    4).http://review.sonyericsson.net/#/c/480849, workaround for fake charge done    
6. 如何查看当前的charger信息?
    /sys/devices/qpnp-charger-eab16c00
7. 手机/sys/class/power_supply/battery和bms和usb的来源
    1)qpnp_charger_proble@kernel/drivers/power/qpnp-charger.c
        if (chip->bat_if_base){
            chip->batt_psy.name = "battery";
            chip->batt_psy.type = POWER_SUPPLY_TYPE_BATTERY;
            chip->batt_psy.properties = msm_batt_power_props;//所选择的属性
            
            rc = power_supply_register(chip->dev, &chip->batt_psy);//注册到/sys/class/power_supply/battery
        }
    2)qpnp_bms_probe@kernel/drivers/power/qpnp-bms.c
        chip->bms_psy.name = "bms";
        chip->bms_psy.type = POWER_SUPPLY_TYPE_BMS;
        chip->bms_psy.properties = msm_bms_power_props;
    
        rc = power_supply_register(chip->dev, &chip->bms_psy);//注册到/sys/class/power_supply/bms
    3)msm_otg_proble@kernel/drivers/usb/otg, 注意CONFIG_USB_MSM_OTG的定义在kernel/drivers/usb/gadget/Kconfig: config USB_CI13XXX_MSM-->select USB_MSM_OTG
        motg->usb_psy.name = "usb";
        motg->usb_psy.type = POWER_SUPPLY_TYPE_USB;
        motg->usb_psy.supplied_to = otg_pm_power_supplied_to;
        
        msm_otg_register_power_supply(pdev, motg))->power_supply_register(&pdev->dev, &motg->usb_psy);
    4)充电器的识别过程
        msm_chg_detect_work@kernel/drivers/usb/otg/msm_otg.c 主要完成充电器类别的识别过程
        ->msm_otg_notify_chg_type@msm_otg.c
            ->power_supply_set_supply_type(psy, charger_type)@msm_otg.c;//psy=motg->usb_psy
            ->psy->set_property(psy, POWER_SUPPLY_PROP_TYPE,&ret); //@kernel/drivers/power/power_supply_core.c, 最后会call
            ->otg_power_set_property_usb@msm_otg.c 但是该函数中没有POWER_SUPPLY_PROP_TYPE属性的设置??
        ->queue_work(system_nrt_wq, &motg->sm_work);->msm_otg_sm_work[otg->phy->state=OTG_STATE_B_IDLE]
            -->msm_otg_notify_charger->msm_otg_notify_power_supply->power_supply_set_online//设置是否online

四、Audio Jack Porting
0. HW Guys: Wang, Junchao(9601), Liu,Xun
1. kernel/sound/soc/msm/msm8226.c;
   kernel/sound/soc/codecs/wcd9306.c,Wcd9xxx-mbhc.c
    tapan_slimbus_irq
2. adb shell 'echo -n "file wcd9xxx-mbhc.c +p" > /sys/kernel/debug/dynamic_debug/control'

3. wcd9xxx_insert_detect_setup@Wcd9xxx-mbhc.c
    0x6c-->0x68  //参考80-NC836-2 WCD9306 AUDIO CODEC SOFTWARE INTERFACE.pdf 中0x14B MBHC_INSERT_DET_STATUS寄存器的说明,PLUG_TYPE 0:NC 1:NO (注意原来的文档有错)
    Audio Jack不插入耳机时MBHC_HSDET是低,插入耳机时MBHC_HSDET是高,所以是Normal Close(NC)类型的Audio Jack
4. @kernel/sound/soc/msm/msm8226.c;
    S(v_no_mic, 30);
    S(v_hs_max, 1650);
5. @kernel/sound/soc/codecs/Wcd9xxx-mbhc.c
    wcd9xxx_codec_get_plug_type->
    wcd9xxx_find_plug_type
6. Audio jack检测耳机的流程
在函数wcd9xxx_mbhc_decide_swch_plug中如果检测到是headset则不重复多次检测,如果是headphone则需要
wcd9xxx_schedule_hs_detect_plug(mbhc,&mbhc->correct_plug_swch);启动重复检测以确认正确
插入headphone耳机
<7>[  105.233608] wcd9xxx_mech_plug_detect_irq: enter
<7>[  105.233625] wcd9xxx_swch_irq_handler: enter
<7>[  105.238692] wcd9xxx_swch_irq_handler: Acquiring BCL
<7>[  105.238706] wcd9xxx_swch_irq_handler: Acquiring BCL done
<7>[  105.238864] wcd9xxx_swch_irq_handler: Current plug type 0, insert 1
<7>[  105.238876] wcd9xxx_cancel_hs_detect_plug: Canceling correct_plug_swch
<7>[  105.238885] wcd9xxx_cancel_hs_detect_plug: Release BCL
<7>[  105.238897] wcd9xxx_cancel_hs_detect_plug: Acquiring BCL
<7>[  105.238907] wcd9xxx_cancel_hs_detect_plug: Acquiring BCL done
<7>[  105.239014] wcd9xxx_mbhc_detect_plug_type: enter
<7>[  105.497933] wcd9xxx_mbhc_decide_swch_plug: enter
<7>[  105.498378] wcd9xxx_codec_get_plug_type: enter
<7>[  105.501350] wcd9xxx_mbhc_setup_hs_polling: enter
...
<7>[  105.590299] wcd9xxx_find_plug_type: DCE #0, fc06, V 0008(0008), GND 0, VDDIO 0, HPHL 1 TYPE 2
<7>[  105.590317] wcd9xxx_find_plug_type: DCE #1, fc06, V 0008(0008), GND 0, VDDIO 0, HPHL 1 TYPE 2
<7>[  105.590332] wcd9xxx_find_plug_type: DCE #2, fc06, V 0008(0008), GND 1, VDDIO 0, HPHL 1 TYPE 2
<7>[  105.590346] wcd9xxx_find_plug_type: DCE #3, fc06, V 0008(0008), GND 0, VDDIO 0, HPHL 1 TYPE 2
<7>[  105.590359] wcd9xxx_find_plug_type: Plug type 2 detected
<7>[  105.590368] wcd9xxx_codec_get_plug_type: leave
<7>[  105.590655] wcd9xxx_report_plug: enter insertion 1 hph_status 0
<7>[  105.590666] wcd9xxx_report_plug: Reporting insertion 1(1)
继续进行检测wcd9xxx_correct_swch_plug,用以确认检测正确,如果检测到是PLUG_TYPE_HEADPHONE则需要在 HS_DETECT_PLUG_TIME_MS=5000毫秒内多次检测
<7>[  105.717321] wcd9xxx_correct_swch_plug: Acquiring BCL
<7>[  105.717335] wcd9xxx_correct_swch_plug: Acquiring BCL done
<7>[  105.717344] wcd9xxx_codec_get_plug_type: enter
<7>[  105.720967] wcd9xxx_mbhc_setup_hs_polling: enter
<7>[  105.804823] wcd9xxx_find_plug_type: DCE #0, fc08, V 0010(0010), GND 0, VDDIO 0, HPHL 1 TYPE 2
<7>[  105.804841] wcd9xxx_find_plug_type: DCE #1, fc08, V 0010(0010), GND 0, VDDIO 0, HPHL 1 TYPE 2
<7>[  105.804856] wcd9xxx_find_plug_type: DCE #2, fc08, V 0010(0010), GND 1, VDDIO 0, HPHL 1 TYPE 2
<7>[  105.804871] wcd9xxx_find_plug_type: DCE #3, fc08, V 0010(0010), GND 0, VDDIO 0, HPHL 1 TYPE 2
<7>[  105.804884] wcd9xxx_find_plug_type: Plug type 2 detected
<7>[  105.804892] wcd9xxx_codec_get_plug_type: leave
<7>[  105.804901] wcd9xxx_correct_swch_plug: Release BCL
<7>[  105.804912] wcd9xxx_correct_swch_plug: attempt(1) current_plug(2) new_plug(2)
<7>[  105.804922] Good headphone detected, continue polling
。。。

拔出耳机
<7>[ 1010.417287] wcd9xxx_mech_plug_detect_irq: enter
<7>[ 1010.417304] wcd9xxx_swch_irq_handler: enter
<7>[ 1010.422617] wcd9xxx_swch_irq_handler: Acquiring BCL
<7>[ 1010.422635] wcd9xxx_swch_irq_handler: Acquiring BCL done
<7>[ 1010.422809] wcd9xxx_swch_irq_handler: Current plug type 2, insert 0
<7>[ 1010.422820] wcd9xxx_cancel_hs_detect_plug: Canceling correct_plug_swch
<7>[ 1010.422830] wcd9xxx_cancel_hs_detect_plug: Release BCL
<7>[ 1010.422842] wcd9xxx_cancel_hs_detect_plug: Acquiring BCL
<7>[ 1010.422851] wcd9xxx_cancel_hs_detect_plug: Acquiring BCL done
<7>[ 1010.422863] wcd9xxx_report_plug: enter insertion 0 hph_status 1
<7>[ 1010.422876] wcd9xxx_report_plug: Reporting removal 1(0)
<7>[ 1010.422911] wcd9xxx_set_and_turnoff_hph_padac PA is off
<7>[ 1010.445247] __hphocp_off_report: clear ocp status 80
<7>[ 1010.445261] __hphocp_off_report: clear ocp status 40
<7>[ 1010.445272] wcd9xxx_insert_detect_setup: Setting up insert detection
<7>[ 1010.445468] wcd9xxx_report_plug: leave hph_status 0
<7>[ 1010.446056] wcd9xxx_swch_irq_handler: Release BCL
<7>[ 1010.446067] wcd9xxx_swch_irq_handler: leave
<7>[ 1010.446079] wcd9xxx_mech_plug_detect_irq: leave 1
<7>[ 1010.446408] wcd9xxx_hs_insert_irq: enter
<7>[ 1010.446418] wcd9xxx_hs_insert_irq: Acquiring BCL
<7>[ 1010.446427] wcd9xxx_hs_insert_irq: Acquiring BCL done
<7>[ 1010.446880] wcd9xxx_hs_insert_irq_swch: Removal
<7>[ 1010.447010] wcd9xxx_hs_insert_irq: Release BCL

插入Headset
<7>[ 1084.338102] wcd9xxx_mech_plug_detect_irq: enter
<7>[ 1084.338119] wcd9xxx_swch_irq_handler: enter
<7>[ 1084.343428] wcd9xxx_swch_irq_handler: Acquiring BCL
<7>[ 1084.343447] wcd9xxx_swch_irq_handler: Acquiring BCL done
<7>[ 1084.343619] wcd9xxx_swch_irq_handler: Current plug type 0, insert 1
<7>[ 1084.343631] wcd9xxx_cancel_hs_detect_plug: Canceling correct_plug_swch
<7>[ 1084.343641] wcd9xxx_cancel_hs_detect_plug: Release BCL
<7>[ 1084.343653] wcd9xxx_cancel_hs_detect_plug: Acquiring BCL
<7>[ 1084.343662] wcd9xxx_cancel_hs_detect_plug: Acquiring BCL done
<7>[ 1084.343676] wcd9xxx_mbhc_detect_plug_type: enter
<7>[ 1084.598139] wcd9xxx_mbhc_decide_swch_plug: enter
<7>[ 1084.598340] wcd9xxx_codec_get_plug_type: enter
<7>[ 1084.601291] wcd9xxx_mbhc_setup_hs_polling: enter
<7>[ 1084.676366] wcd9xxx_find_plug_type: DCE #0, 026d, V 1306(1306), GND 0, VDDIO 0, HPHL 1 TYPE 1
<7>[ 1084.676384] wcd9xxx_find_plug_type: DCE #1, 02b7, V 1365(1365), GND 0, VDDIO 0, HPHL 1 TYPE 1
<7>[ 1084.676399] wcd9xxx_find_plug_type: DCE #2, 02bb, V 1368(1368), GND 1, VDDIO 0, HPHL 1 TYPE 1
<7>[ 1084.676414] wcd9xxx_find_plug_type: DCE #3, 02bb, V 1368(1368), GND 0, VDDIO 0, HPHL 1 TYPE 1
<7>[ 1084.676427] wcd9xxx_find_plug_type: Plug type 1 detected
<7>[ 1084.676436] wcd9xxx_codec_get_plug_type: leave
<7>[ 1084.676720] wcd9xxx_mbhc_decide_swch_plug: Valid plug found, determine plug type 1
<7>[ 1084.676733] wcd9xxx_find_plug_and_report: enter current_plug(0) new_plug(1)
<7>[ 1084.676745] wcd9xxx_report_plug: enter insertion 1 hph_status 0
<7>[ 1084.676755] wcd9xxx_report_plug: Reporting insertion 3(3)
<7>[ 1084.676802] wcd9xxx_insert_detect_setup: Setting up removal detection
<7>[ 1084.676955] wcd9xxx_report_plug: leave hph_status 3
<7>[ 1084.777467] wcd9xxx_start_hs_polling: enter
<7>[ 1084.779191] wcd9xxx_start_hs_polling: leave
<7>[ 1084.779202] wcd9xxx_find_plug_and_report: leave
<7>[ 1084.779212] wcd9xxx_mbhc_decide_swch_plug: leave
<7>[ 1084.779221] wcd9xxx_mbhc_detect_plug_type: leave
<7>[ 1084.779229] wcd9xxx_swch_irq_handler: Release BCL
<7>[ 1084.779238] wcd9xxx_swch_irq_handler: leave
<7>[ 1084.779250] wcd9xxx_mech_plug_detect_irq: leave 1




五、如何flash开发板
1. lunch
2. fastboot flash boot boot.img, flash kernel的image
   fastboot flash system system.img, flash system的image

六、SIM card detection
1. kernel/arch/arm/boot/dts/msm8226-cn3ii.dts 中有gpio_keys节点
    gpio_keys {
        compatible = "gpio-keys"
        input-name = "gpio-keys"  //表示输出event的名字
        ...
    }
   kernel/drivers/input/keyboard/gpio_keys.c会解析 gpio-keys 的dts
   增加sim card detection 的gpio key
   sim1 {
    ompatible = "gpio-keys";    
    input-name = "sim1-detection";    
    
    sim1_det {    
        label = "sim1-detection";    
        gpios = <&msmgpio 60 0x0>;    //msmgpio表示使用的是8226的gpio, 60表示GPIO60
        linux,input-type = <5>;        //define EV_SW 0x05
        linux,code = <7>;        //#define SW_JACK_PHYSICAL_INSERT 0x07  /* set = mechanical switch set */
        gpio-key,wakeup;    
        debounce-interval = <10>;    
    };    
   };
2. http://review.sonyericsson.net/#/c/518583
3. https://wiki.sonyericsson.net/androiki/FP8615_Support_for_SIM_detection_for_Zeus_Docomo_Definition_Report

七、Vibrator
1. 检查是否工作 #echo 1000 > /sys/class/timed_output/vibrator/enable

八、GPIO设置的确认
1. msmgpio@kernel/arch/arm/boot/dts/msm8226-cn3ii.dtsi
    msmgpio: gpio@fd510000 {
        compatible = "qcom,msm-gpio";
        interrupt-controller;
        #interrupt-cells = <2>;
        reg = <0xfd510000 0x4000>;
        gpio-controller;
        #gpio-cells = <2>;
        ngpio = <117>;
        interrupts = <0 208 0>;
        qcom,direct-connect-irqs = <8>;
    };  
2. pm8226_gpios@kernel/arch/arm/boot/dts/msm8226-cn3ii.dts
    &pm8226_gpios {
        gpio@c000 { /* GPIO 1 */
        /* XO_PMIC_CDC_MCLK enable for tapan codec */
        qcom,mode = <1>;        /* Digital output */
        qcom,output-type = <0>; /* CMOS logic */
        qcom,pull = <5>;        /* QPNP_PIN_PULL_NO*/
        qcom,vin-sel = <2>;     /* QPNP_PIN_VIN2 */
        qcom,out-strength = <3>;/* QPNP_PIN_OUT_STRENGTH_HIGH */
        qcom,src-sel = <2>;     /* QPNP_PIN_SEL_FUNC_1 */
        qcom,master-en = <1>;   /* Enable GPIO */
        };  

        gpio@c100 { /* GPIO 2 */
        qcom,mode = <1>;
        qcom,output-type = <0>;
        qcom,pull = <5>;
        qcom,vin-sel = <2>;
        qcom,out-strength = <3>;
        qcom,src-sel = <2>;
        qcom,master-en = <1>;
        };  
    ...    
    }
3. http://review.sonyericsson.net/#/c/518583/
4. GPIO 如何配置成I2C
    1)@kernel/arch/arm/boot/dts/msm8226-cn3ii.dtsi, 以下设置i2c的参数
        i2c@f9926000 { /* BLSP-1 QUP-4 */
            cell-index = <0>;
            compatible = "qcom,i2c-qup";
            reg = <0xf9926000 0x1000>;
            #address-cells = <1>;
            #size-cells = <0>;
            reg-names = "qup_phys_addr";
            interrupts = <0 98 0>;
            interrupt-names = "qup_err_intr";
            qcom,i2c-bus-freq = <400000>;
            qcom,i2c-src-freq = <400000>;
            ti_lm3630_bl@36{
                compatible = "ti,lm3630_bl";
                reg = <0x36>;
                gpio_hw_en = <&msmgpio 27 0>;
                pwm_feedback = <0x08 0x10>;
                ctl = <0x00 0x00>;
                fsc = <20200 20200>;
                iname = "lm3630-lcd-bl-1","lm3630-lcd-bl-2";
                connected = <0x01 0x01>;
                bank = <0x00 0x01>;
                filter_str = <0x03>;
                ovp_boost = <0x24>;
                led_fault = <0x00>;
                intf_name = "lm3630-lcd-bl-1","lm3630-lcd-bl-2";
                brightness = <255 255>;
            };
        };
    2)kernel/arch/arm/mach-msm/board-sony_cn3ii-gpiomux.c,以下配置GPIO14和15为I2C的功能,即GPIOMUX_FUNC_3
    static struct msm_gpiomux_config msm_blsp_configs[] __initdata = {
        {
            .gpio      = 14,    /* BLSP1 QUP4 I2C_SDA */
            .settings = {
                [GPIOMUX_SUSPENDED] = &gpio_i2c_config,
            },
        },
        {
            .gpio      = 15,    /* BLSP1 QUP4 I2C_SCL */
            .settings = {
                [GPIOMUX_SUSPENDED] = &gpio_i2c_config,
            },
        },
    }
    static struct gpiomux_setting gpio_i2c_config = {
        .func = GPIOMUX_FUNC_3,
        .drv = GPIOMUX_DRV_2MA,
        .pull = GPIOMUX_PULL_NONE,
    };
八、GPIO Check
1. AP GPIO:
    kernel/arch/arm/mach-msm/board-sony_cn3ii-gpiomux.c //这其中只是定义了某个GPIO的配置,如果程序需要使用,还要gpio_request
        /
   PMIC GPIO:
    kernel/arch/arm/boot/dts/msm-pm8226.dtsi中有pm8226_gpios的定义    
    kernel/arch/arm/boot/dts/msm8226-cn3ii.dts中的&pm8226_gpios,
        kernel/drivers/gpio/gpnp-pin.c 中会解析pm8226_gpios dts.
2. HW Guy: Liu, Helson for GPIO setting.
3. GPIO设置文档http://metadoc.sonyericsson.net/login_link.asp?doc=1/10262-17/FCP1191405/6&rev=latest
4. 还可以在 cat sys/kernel/debug/gpio 确认当前GPIO的状态


九、battery logging port
1. device/somc/yangtze/BoardConfig.mk
    # battery logging   //打开编译libbatterylogging的开关
    ifneq ($(TARGET_BUILD_VARIANT), user)
    SONY_CFG_LIBBATTERYLOGGING := true
    endif
   device/somc/yangtze/platform.mk
    ->PRODUCT_PACKAGES += battery_logging  //添加battery_logging编译目录

   device/somc/yangtze/files/init.sony-platform.rc
    ONLY_IN_DEBUG(  //设置是否 实时开始和停止运行battery_logging, 其定义在/build/core/definitions.mk (-DONLY_IN_DEBUG)
            //实际上表示只要编译的版本是eng和userdebug版本都需要执行
    on property:battery_log=1    //init.c分析时会把property:battery_log 当作一个action 的条件加入trigger链表,当通过setprop改变
                    //battery_log的属性时会触发该action: start/stop battery_logging
                    //具体的代码分析:property_set@system/core/init/property_service.c
        start battery_logging
    on property:battery_log=0    //setprop battery_log 0 可以停止battery_logging service,
        stop battery_logging)

    ONLY_IN_VARIANT(eng,        //其定义在/build/core/definitions.mk (-DONLY_IN_VARIANT)
    on property:dev.bootcomplete=1
        start battery_logging)

    ONLY_IN_VARIANT(userdebug,
    on property:dev.bootcomplete=1
        start battery_logging)

    ONLY_IN_DEBUG(
    service battery_logging /system/bin/battery_logging
        disabled) //disable表示需要手动启动
2. vendor/semc/hardware/device/yangtze/libbatterylogging
    ->out/target/product/cn3ii/obj/STATIC_LIBRARIES/libbatterylogging_intermediates/libbatterylogging.a
3. vendor/semc/hardware/power/charge-log/battery_logging
    ->out/target/product/cn3ii/system/bin/battery_logging
4. #battery_logging -p //输出所有的需要输出信息的名称和路径
  #battery_logging -d //输出运行时的log
十、device tree source(DTS)
0. http://devicetree.org/Main_Page
1. *.dts/dtsi 文件一般位于 kernel/arch/arm/boot/dts,比如msm8226-cn3ii.dts  msm8226-cn3ii.dtsi
2. 如何决定用那个*.dts文件?
   @kernel/arch/arm/mach-msm/Makefile.boot
    # MSM8226
       zreladdr-$(CONFIG_ARCH_MSM8226)  := 0x00008000 //是啥地址?
    dtb-$(CONFIG_MACH_SONY_CN3II) += msm8226-cn3ii.dtb
    @kernel/arch/arm/configs/cn3ii_defconfig    
    CONFIG_ARCH_MSM8226=y
    CONFIG_MACH_SONY_CN3II=y

3. 编译dts为dtb的工具为DTC,位于kernel/scripts/dtc
    hostprogs-y := dtc //@Makefile中,该行表示用hostprogs编译生成dtc
    最后生成的dtc可执行文件位于out/target/product/cn3ii/obj/KERNEL_OBJ/scripts/dtc/dtc
4.用dtc编译*.dts生成的*.dtb文件位于
    out/target/product/cn3ii/obj/KERNEL_OBJ/arch/arm/boot/msm8226-cn3ii.dtb
    存放在手机什么地方?
    bootloader如何读取?如何传递给kernel?
    head-common.S@kernel\arch\arm\kernel中有    
    .long    __atags_pointer @ r6 //表示保存dtb的地址通过r6传递给kernel

5. kernel中解析DTS
    setup_machine_fdt@kernel/arch/arm/kernel/devtree.c
    struct boot_param_header *devtree = phys_to_virt(dt_phys); //注意boot_param_header结构
    setup_machine_fdt将分析dtb最后所有devices生成树,如何和以前的版本结果就一样了
6. kernel中各个device和driver谁先加载?

十一、charge only porting
1. device/somc/common/sony-generic.mk 添加
    -include vendor/semc/hardware/device/device.mk
2. device/somc/yangtze/files/init.sony-platform.rc 中添加
    on early-boot
        exec /system/bin/chargemon
        //write /sys/class/power_supply/battery/enable_stop_charging_at_low_battery 1
   device/somc/yangtze/BoardConfig.mk 增加
    # Device sysfs path definitions
    TARGET_BACKLIGHT_DEVICE_PATH := /sys/class/leds/wled:backlight/brightness
    TARGET_LED_R_DEVICE_PATH := /sys/class/leds/led:rgb_red/brightness
    TARGET_LED_G_DEVICE_PATH := /sys/class/leds/led:rgb_green/brightness
    TARGET_LED_B_DEVICE_PATH := /sys/class/leds/led:rgb_blue/brightness
    TARGET_DISPLAY_DEVICE_PATH := /sys/devices/mdss_dsi_panel
3. vendor/semc/hardware/device/目录下添加device.mk 和 cn3ii/cn3ii.mk, 添加以下关键内容
    @device.mk
     DEVICE_CONFIG=vendor/semc/hardware/device
     # Call product specific makefiles.
     -include $(DEVICE_CONFIG)/$(TARGET_PRODUCT)/$(TARGET_PRODUCT).mk
     # Call platform specific makefiles.
     -include $(DEVICE_CONFIG)/yangtze/platform.mk
    @cn3ii.mk
    SONY_CFG_CHARGEMON := true
    PRODUCT_PACKAGES += chargemon
  vendor/semc/hardware/device/yangtze$ 目录下添加chargemon_common.mk和platform.mk
     @platform.mk    
    PLATFORM_DEVICE_CONFIG=vendor/semc/hardware/device/yangtze
    # chargemon
    include $(PLATFORM_DEVICE_CONFIG)/chargemon_common.mk
6. 注意:
    *.rc 文件放在ramdisk中,而一般打包在boot.img或kernel.sin中
    修改完*.mk文件后,需要重新lunch才会生效
7. 如何debug
    #define DEBUG_LOG //在log.h中定义,打开log输出到手机 data/cm.log
    LOGM(2); //在main代码中打开log输出mode,

十二、电池充电的几个关键过程
Trigle charge:
0. 当电池电压很低时,如何charge?
1. Vbat>3.42V,直接进入sys boot; Vbat<3.42时进入SBL的充电逻辑,Vbat<2.9v进入SBL的trigle charge(200mA充电),当超过2.9v时,进入SBL的fast charge模式(500mA充电),一直充直到Vbat>3.7V后,boot sys.
进入trigle charge mode,然后当电池电压充到3.7V(system weak threshod, Vweak)则退出trigle charge mode,启动kernel
2. Auto trigle charge(ATC)的触发条件: 电池电压< Vweak系统需要启动的最低电压,然后 充电电流被限制在100mA;手机不能用100mA的电流启动。
3. Two-step ATC 目前没有用,当电池电压特别低时分两步充电
    a. Vbat < Vtrkl, Buck off, Bat FET closed, 充电电流50mA-200mA,小电流充电, Vtrkl一般设置区间为2.05V-2.8V
    b. Vweak > Vbat > Vtrkl, Buck on, Bat FET closed,充电电流300mA-500mA, Vweak一般设置区间为2.1V-3.6V
4. 用FLCB 充电,目前CN3-ii用该方案
    Buck on, Bat FET open, 用VCHG直接给电池充电,不经过Bat FET.一直用ITRKL电流给电池充电,该Itrkl电流一般多大?
    当Vbat > Vweak后,系统就启动了

Fast charging
1. CC , Vweak < Vbat < Vbat_max, 用最大电流IBAT_MAX 给电池充电,IBAT_MAX的一般取值区间300mA-3000mA
2. CV, Vbat > Vbate_max, 逐渐降低充电电流Ibat,直到给电池的充电电压VPH_PWR==VDD_MAX,VDD_MAX一般设置区间3.4V-4.5V

Charging termination[依据的是充电电流大小]
1. 结束条件:Ibat(充电电流) < Iterm (with deglitching),Iterm一般设置区间35mA-276mA
2. 结果:Bat FET Open, Buck on 这样仍然可以给系统供电。如果系统需要的电流>Buck能提供的,那么Battery如何供电给系统?Bat FET Open也能反向把电流从电池输送给系统吗?

Automatic Recharge[依据的是电池电压大小]
1. 开始条件:Vbat < Vbat_det, 一般Vbat_det设置区间是3.3V-4.7V
2. 结果,又进入Fast charging阶段

OVP(过压保护)
1. 从外部USB 进入的电压保护范围[5v,28v],可以设置该指?如果大于这最大进入电压,则第一级的保护电路生效。
2. 进入第二级保护电路,如果通过1进入的电压,大于预先SSBI-programmable设定的门限(该门限设置区间[5.5v,7v]),如果电压大于该门限,则OVP FET会OPEN,反之。



十三、如何读写充电寄存器
1. 读寄存器
   echo 0xccc > /sys/kernel/debug/spmi/spmi-0/address
   echo 0xccc > /sys/kernel/debug/spmi/spmi-0/count
   cat /sys/kernel/debug/spmi/spmi-0/data
   写寄存器
   echo 0xccc > /sys/kernel/debug/spmi/spmi-0/address
   echo 0xccc > /sys/kernel/debug/spmi/spmi-0/data    
2. 如何控制使用内部或外部电阻rsense.
   0x3848 IADC2_BMS_ADC_CH_SEL_CTL
   0x0: INTRSNS
   0x1: EXTRSNS
   @kernel/arch/arm/boot/dts/msm8226-cn3ii.dtsi中
   &pm8226_bms {
       qcom,use-external-rsense = <1>;
   }

   qcom,pm8226@0 {
    iadc@3600 {
            qcom,rsense = <10000000>;
    };   
   };

3. 另外Huashan PM8921的路径为: sys/kernel/debug/pm8921-dbg

十四、增加识别wall charger
http://review.sonyericsson.net/#/c/534625/

十五、如何disable/enable充电
1. [User]SysFS: /sys/class/power_supply/battery/charging_enabled;
   在charge only程序中,会通过miscTA 2312的值,来判断是否diable/enable充电(1:disable;非1:enable)
   disableCharging@vendor/semc/hardware/power/chargemon/src/main.c
   hw_disableCharging@vendor/semc/hardware/power/chargemon/src/main.c
    ->hw_writeSysfs(DISABLE_CHARGING_PATH, DISABLE_CHARGING); //DISABLE_CHARGING_PATH=/sys/class/power_supply/battery/charging_enabled
  [Kernel]的对应处理 qpnp_batt_power_set_property@kernel/drivers/power/qpnp-charger.c
    chip->charging_disabled = !(val->intval);
    qpnp_chg_charge_en(chip, !chip->charging_disabled); //操作0x1049的bit7,主要控制FSM是否工作
    qpnp_chg_force_run_on_batt(chip, chip->charging_disabled);//0x1049的bit7,主要控制所有与电池相关的功能(trikle charger, buck reg, batfet)是否工作。
2. Debugmenu中如何控制充电
   @vendor/semc/packages/apps/debugmenu/src/com/sonyericsson/debugmenu/charging.java中会操作MiscTA 2312, 写入1 disable或0 enable;
   然后下次启动运行charge only的时候会根据该Misc TA的值,enable/disbale充电。


十六、Charge only中的重要控制
1. charge only 是否进入的控制。
   miscTA 2311, 0: 可以进入charge only; 2: 这次不让进入,但下次让进入; 其他(1):不让进入charge only.
2. 在charge only程序中是否充电
   miscTA 2312的值,来判断是否diable/enable充电(1:disable;非1:enable)
   /sys/class/power_supply/battery/charging_enabled;     
3. Android USB device的控制
   sys/class/android_usb/android0/enable 控制是否enable ADB功能
   sys/class/android_usb/android0/functions, 设置USB支持的功能,在属性sys.usb.config,两者一致
   sys/class/android_usb/android0/idProduct or idVendor, 重置USB的ID,但必须先disable USB
   @vendor/semc/hardware/device/yangtze/chargemon_common.mk中有如下定义
    USB_VENDOR_ID := 0fce
    USB_PRODUCT_ID := e000
    USB_ACCESSORY_VID := 18d1
    USB_ACCESSORY_PID := 2d00
    MASS_STORAGE := mass_storage
    ACCESSORY := accessory
    USB_ENABLE_PATH := /sys/class/android_usb/android0/enable
    USB_SETFUNC_PATH := /sys/class/android_usb/android0/functions
    USB_PRODUCT_ID_PATH := /sys/class/android_usb/android0/idProduct
    USB_VENDOR_ID_PATH := /sys/class/android_usb/android0/idVendor
   @device/somc/cn3ii/System.prop,中有 ro.usb.pid_suffix=1A9 重新设置USB PID
   $在Ubantu上lsusb可以所有的usb device,其中就包括
   Bus 001 Device 111: ID 0fce:51a9 Sony Ericsson Mobile Communications AB ,
   
   idProduct,idVendor,function是在那里设定的?
   @device/somc/common/files/init.sony.usb.rc
    on property:sys.usb.config=mtp,adb //任何sys.usb.config的改变,就会触发后面的动作
    exec /init.usbmode.sh
    start adbd
    setprop sys.usb.state ${sys.usb.config}
   @device/somc/common/files/init.usbmode.sh
          VENDOR_ID=0FCE
    PID_SUFFIX_PROP=$(/system/bin/getprop ro.usb.pid_suffix)
    USB_FUNCTION=$(/system/bin/getprop sys.usb.config)
    get_pid_prefix ${USB_FUNCTION}中确定PID_PREFI的值,实际上是根据sys.usb.config
    PID=${PID_PREFIX}${PID_SUFFIX_PROP},其中PID_PREFIX表示sony自己定义的功能 5:mtp,adb;0:mtp
    echo ${VENDOR_ID} > /sys/class/android_usb/android0/idVendor
    echo ${PID} > /sys/class/android_usb/android0/idProduct
   @device/somc/common/sony-generic.mk
    ADDITIONAL_DEFAULT_PROPERTIES += persist.sys.usb.config=mtp 但是只设置了mtp功能,没有adb功能?
   @frameworks/base/services/java/com/android/server/usb/usbdevicemanager.java
    函数setEnabledFunctions(..) 会根据setting UI的设置改变persist.sys.usb.config的值
                if (mAdbEnabled) {
                    functions = addFunction(functions, UsbManager.USB_FUNCTION_ADB);
                } else {
                    functions = removeFunction(functions, UsbManager.USB_FUNCTION_ADB);
                }
        SystemProperties.set("persist.sys.usb.config", functions);
   有个问题,设置persist.sys.usb.config是如何传到sys.usb.config的???
   @system/core/rootdir/init.usb.rc
    on property:persist.sys.usb.config=*
        setprop sys.usb.config none
        setprop sys.usb.config ${persist.sys.usb.config} //两者会同步
4. 可以优化的地方
    a. 现在charge eoc后,如果拔掉充电器,则会上报report key KEY_F24, charge only process会在
        hw_waitForUserAction@vendor/semc/hardware/power/chargemon/src/hw.c中
        hw_wakeUnlock();
        i = select(max_fd + 1, &listen, NULL, NULL, &delay);//等待5秒,也只有在这5秒中,系统才有机会suspend
        hw_wakeLock();
           而上报KEY_F24事件,主要是解决在charge only模式下,系统深度睡眠,拔掉充电器时,charge only不会退出关机
    b. 而在 check_plugin_wakelock@kernel/drivers/power/qpnp-charger.c中,当拔掉充电器时会有wakelock,超时2秒
        wake_lock_timeout(&chip->somc_params.plugin_wake_lock, PLUGIN_WAKELOCK_TIME_SEC);
    c. 由此,是否可以不需要上报KEY_F24给charge only呢?直需要缩短 select 的延时<2秒,就可以避免charge only不会退出关机的问题
    

十七、电池参数的设置(百分比,温度,电压 之间的关系)
1. @kernel/arch/arm/boot/dts/msm8226-cn3ii.dtsi
    &pm8226_bms {
        qcom,batt-type = <3>;  //电池类型为 BATT_OEM
    }
    @kernel/arch/arm/mach-msm/Makefile, 当前用的是pc_temp_ocv@bms-batterydata-sleipner.c
    ifdef CONFIG_MACH_SONY_CN3II
    obj-$(CONFIG_MACH_SONY_CN3II) += bms-batterydata-sleipner.o
    设置电池的相关参数        
    set_battery_data@kernel/drivers/power/qpnp-bms.c
    插值计算@kernel/arch/arm/mach-msm/baterydata-lib.c

十八、电池低电关机过程
1. 涉及关机的几个参数配置
    pm8226_bms: qcom,bms {
        qcom,v-cutoff-uv = <3400000>;  //关机电压,但只用与计算SOC
        qcom,low-soc-calculate-soc-threshold = <15>; //认为是低电的电池百分比
            qcom,low-soc-calculate-soc-ms = <5000>;  //低电情况下的心跳
            qcom,calculate-soc-ms = <20000>;
        qcom,low-voltage-threshold = <3420000>;
    }
2. 系统休眠情况下的低电关机触发
   setup_vbat_monitoring@kernel/drivers/power/qpnp-bms.c 中会设置低电(高电,高温,低温)的threshold,
   还有call back函数btm_notify_vbat, 如果电压低于low-voltage-threshold-VBATT_ERROR_MARGIN也就是3.4V
    ->configure_vbat_monitor_low
        唤醒系统 wake_lock(&chip->low_voltage_wake_lock);
        开始计算soc, schedule_delayed_work(&chip->calculate_soc_delayed_work, 0);
        针对电池低压的情况下,重新配置参数
           如果此时soc=0,则上报android 关机
3. 系统正常情况下的低电关机触发
    开机后马上运行 calculate_soc_work,以后只要系统不休眠则 心跳间隔20s(soc > 15%),5s(soc < 15% & wake_lock_active(&chip->low_voltage_wake_lock))
    ->recalculate_soc
    ->calculate_state_of_charge    
    ->adjust_soc
        ->very_low_voltage_check 如果电池电压<3.42v,则wake_lock(&chip->low_voltage_wake_lock);不让系统休眠,    随后心跳间隔一直继续,上报soc,如果soc=0则系统会关机。
 
十九、PMIC中充电部分中断的申请和处理
1. @kernel/arch/arm/boot/dts/msm-pm8226.dtsi
            qcom,chgr@1000 {
                status = "disabled";
                reg = <0x1000 0x100>;
                interrupts =    <0x0 0x10 0x0>,
                        <0x0 0x10 0x1>,
                        <0x0 0x10 0x2>,
                        <0x0 0x10 0x3>,
                        <0x0 0x10 0x4>,
                        <0x0 0x10 0x5>, //"fast-chg-on"对应的寄存器0x1000 + 0x10 = 0x1010, 0x05表示的是第5个bit
                        <0x0 0x10 0x6>,
                        <0x0 0x10 0x7>;

                interrupt-names =   "vbat-det-lo",
                            "vbat-det-hi",
                            "chgwdog",
                            "state-change",
                            "trkl-chg-on",
                            "fast-chg-on",
                            "chg-failed",
                            "chg-done";
            };  
    对应的是SMBBP_CHAR_SMNNP_CHAR中 0x1010 SMBBP_CHGR_INT_RT_STS 中断寄存器的bits
2. 如何引用,例子如下:
   qpnp_chg_request_irqs@kernel/drivers/power/qpnp-charger.c
    chip->chg_fastchg.irq = spmi_get_irq_byname(spmi,spmi_resource, "fast-chg-on");

二十、充电最大时间设置(trickle + fast charging)
1. @kernel/arch/arm/boot/dts/msm-pm8226.dtsi
    pm8226_chg: qcom,charger {
        qcom,tchg-mins = <150>; //表示150分钟, 取值区间[4, 512]分钟
    }
2. qpnp_charger_read_dt_props@kernel/drivers/power/qpnp-charger.c
    OF_PROP_READ(chip, tchg_mins, "tchg-mins", rc, 1);
   qpnp_chg_hwinit
    rc = qpnp_chg_tchg_max_set(chip, chip->tchg_mins); //此处往寄存器0x1061 SMBBP_CHGR_TCHG_MAX 写入
3. 如果需要disable 充电最大时间的限制,则需要操作 寄存器0x1060 SMBBP_CHGR_TCHG_MAX_EN
4. 如果需要设置trickle charge的最大时间限制,则需要操作 寄存器0x105F SMBBP_CHGR_TTRKL_MAX,
   enable/disable 则需要操作 寄存器0x105E SMBBP_CHGR_TTRKL_MAX_EN,

二十一、当kernel用power_supply_changed 发送uevent 到 userspace的后续处理
1. register_android_server_BatteryService@frameworks/base/services/jni/com_android_server_BatteryService.cpp 注册的sys path如下:
    /sys/class/power_supply/???/online  其中???/type=Mains //注意大小写是区分的
    /sys/class/power_supply/usb/online  其中usb/type=USB
    /sys/class/power_supply/battery/online   其中usb/type=Battery
    /sys/class/power_supply/battery/status
    /sys/class/power_supply/battery/health
    /sys/class/power_supply/battery/present
    /sys/class/power_supply/battery/capacity
    /sys/class/power_supply/battery/voltage_now[batt_vol]
    /sys/class/power_supply/battery/temp[batt_temp]
    /sys/class/power_supply/battery/technology
2. 如果是power_supply_changed(&chip->batt_psy);则user space 会读取所有注册的关于battery 的sys path.

二十二、如何在kernel添加input key event给user space用
   @kernel/drivers/power/qpnp-charger.c
   注册/* register input device */
    chip->somc_params.chg_unplug_key = input_allocate_device();
    input_set_capability(chip->somc_params.chg_unplug_key,    EV_KEY, KEY_F24);
    chip->somc_params.chg_unplug_key->name = "qpnp_chg_unplug_key";
    chip->somc_params.chg_unplug_key->dev.parent = &(spmi->dev);
    rc = input_register_device(chip->somc_params.chg_unplug_key);    
        //input_free_device(chip->somc_params.chg_unplug_key);
   使用:
    input_report_key(chip->somc_params.chg_unplug_key, KEY_F24, value ? 1 : 0);
    input_sync(chip->somc_params.chg_unplug_key);

二十三、chager debug
1. echo -n "file qpnp-charger.c +p" > /sys/kernel/debug/dynamic_debug/control
2. disable charging:
    echo 0 > /sys/class/power_supply/battery/charging_enabled
3. WARN_ON(1) & BUG_ON

二十四、高通Case和公司DMS的关系
1. 如果遇到问题是高通的bug,提交一个case给高通
2. 在公司的DMS中创建一个主DMS, 并且assign给 coordinator, 并且在Attachments/Reference页签中的External References上
    External Reference 选择Qcom
    External Reference ID 输入 Qcom的case ID;
3. 如果Qcom的solution没有及时deliver, 我们可以创建一个child dms, 在Linked Records页签中单击 Create Child,在该child DMS中diliver我们自己的solution;一旦Qcom diliver了Solution,则我们自己的solution需要revert.

二十五、 Touch screen, Display新的early suspend机制
1. User space 如果需要early suspend,则需要操作 "/dev/graphics/fb0"
    ioctl(fb.fd, FBIOBLANK, FB_BLANK_UNBLANK);  //resume
    ioctl(fb.fd, FBIOBLANK, FB_BLANK_POWERDOWN);  //suspend
2. 通过操作display的ioctl, 进而控制其他需要early supend的设备,主要机制是notify的回调
    do_fb_ioctl@kernel/drivers/video/fbmem.c
    fb_blank(info, arg)@kernel/drivers/video/fbmem.c
    fb_notifier_call_chain(FB_EVENT_BLANK, &event)@kernel/drivers/video/fbmem.c
    blocking_notifier_call_chain@kernel/kernel/notifier.c
    notifier_call_chain(&nh->head, val, v, nr_to_call,nr_calls)@kernel/kernel/notifier.c
    nb->notifier_call(nb, val, v)@kernel/kernel/notifier.c
3. 需要和display一块suspend的设备如何注册notify, 比如touch screen
     clearpad_probe@kernel/drivers/input/touchscreen/clearpad_core.c
    this->fb_notif.notifier_call = synaptics_fb_notifier_callback;
    rc = fb_register_client(&this->fb_notif); //注册display notify的关键函数    
  另外还注册正常的linux power管理的suspend/resume
    static const struct dev_pm_ops synaptics_clearpad_pm = {
        .suspend = synaptics_clearpad_pm_suspend,
        .resume = synaptics_clearpad_pm_resume,
        .suspend_noirq = synaptics_clearpad_pm_suspend_noirq,
    };
   以上两条suspend的路径最后都调用 synaptics_clearpad_suspend和synaptics_clearpad_resume

二十六、低电关机(soc=0%和电压低于设置的低电压 都会触发低电关机)
1. 电压低于设置电压的处理
    @msm-pm8226.dtsi中 
    pm8226_bms: qcom,bms{
        qcom,low-soc-calculate-soc-threshold = <15>; //认为是低电压的soc(15%)
        qcom,low-soc-calculate-soc-ms = <5000>; //低电压情况下,计算soc 的时间间隔5s
        qcom,calculate-soc-ms = <20000>; //正常情况下,计算soc 的时间间隔20s
        qcom,v-cutoff-uv = <3400000>;//用于计算soc
        qcom,low-voltage-threshold = <3420000>;//用于设置关机低电压
    }
2. 系统一开机会马上运行calculate_soc_work,然后间隔20s或5s 循环执行,只要系统不suspend,该schedule work会一直执行,如果s计算的soc有变化还会power_supply_changed上报给用户空间,如果此时soc=0%则用户空间会强制关机shut down.
   
3. 另外还有一种情况,就是系统已经suspend,但电池电压小于预先设置的门限电压,会触发notify也就是btm_notify_vbat@qpnp-bms.c,如果是低电状态则继续调用configure_vbat_monitor_low,其中会wake_lock(&chip->low_voltage_wake_lock);让系统不再suspend,马上开始运行calculate_soc_work,也就是把soc=0%的信息赶快通知给user space,好执行低电关机。具体分析如下:
3.1 设置低电notify的相关参数,setup_vbat_monitoring@qpnp-bms.c
   ->qpnp_adc_tm_channel_measure@qpnp-adc-tm.c; 设置adc channel的监控设置
    chip->vbat_monitor_params.low_thr = chip->low_voltage_threshold; //低电压门限设置
    chip->vbat_monitor_params.high_thr = chip->max_voltage_uv - VBATT_ERROR_MARGIN; //高电压门限设置
    chip->vbat_monitor_params.state_request = ADC_TM_HIGH_LOW_THR_ENABLE; //触发的类型 满足高低电压门限时触发
    chip->vbat_monitor_params.channel = VBAT_SNS;
    chip->vbat_monitor_params.btm_ctx = (void *)chip;
    chip->vbat_monitor_params.timer_interval = ADC_MEAS1_INTERVAL_1S; //Polling 时间
    chip->vbat_monitor_params.threshold_notification = &btm_notify_vbat; //回调函数
    rc = qpnp_adc_tm_channel_measure(&chip->vbat_monitor_params);
3.2 @qpnp-adc-tm.c
    notify_adc_tm_fn是其中关键的处理函数
    ->notify_clients(adc_tm)-->adc_tm->btm_param->threshold_notification(ADC_TM_LOW_STATE, adc_tm->btm_param->btm_ctx);
    qpnp_adc_tm_probe中初始化INIT_WORK(&adc_tm->sensor[sen_idx].work, notify_adc_tm_fn);
      初始化qpnp_adc_tm_low_thr_isr中断处理函数
        rc = devm_request_irq(&spmi->dev, adc_tm->adc->adc_low_thr_irq,
                qpnp_adc_tm_low_thr_isr,IRQF_TRIGGER_RISING, "qpnp_adc_tm_low_interrupt", adc_tm);
    一旦电压低于chip->vbat_monitor_params.low_thr则触发qpnp_adc_tm_low_thr_isr,然后schedule_work(qpnp_adc_tm_low_thr_work);最后会调用qpnp_adc_tm_read_status,又会触发schedule_work(&adc_tm->sensor[sensor_num].work);即notify_adc_tm_fn函数,从而会发notify消息给BMS的btm_notify_vbat->configure_vbat_monitor_low和power_supply_changed

二十七、读取的adc电压和电池温度的关系
1. @kernel/drivers/hwnon/qpnp-adc-common.c
    计算电池温度和电压关系的函数qpnp_adc_scale_batt_therm
    电池温度和电压关系的对应表adcmap_btm_threshold[], 该表需要电池team提供
        static const struct qpnp_vadc_map_pt adcmap_btm_threshold[] = {
            {-300,    1686},    ...  
            {0,    1342}, ...
            {450,    619}, ... {温度45度,电压619mv}
        }
    通过线性逼近插值计算精度可以到达0.1Degc
2. 读取电池温度的流程
    get_prop_batt_temp@kernel/drivers/power/qpnp-charger.c
    qpnp_vadc_read(LR_MUX1_BATT_THERM, &results)@kernel/drivers/hwmon/qpnp-adc-voltage.c
    qpnp_vadc_conv_seq_request(ADC_SEQ_NONE, channel, result)@kernel/drivers/hwmon/qpnp-adc-voltage.c
    vadc_scale_fn[scale_type].chan(result->adc_code,vadc->adc->adc_prop, vadc->adc->amux_prop->chan_prop, result)@qpnp-adc-voltage.c
    qpnp_adc_scale_batt_therm@kernel/drviers/hwmon/qpnp-adc-common.c
   重点分析qpnp_vadc_conv_seq_request@qpnp-adc-voltage.c
    a. vadc->adc->adc_channels 的赋值
           qpnp_adc_get_devicetree_data@qpnp-adc-common.c
       ->adc_qpnp->adc_channels = adc_channel_list;其中adc_channel_list是分析读取msm8226-cn3ii.dtsi中&pm8226_vadc的节点内容,其中有
                chan@30 {
                label = "batt_therm";
                reg = <0x30>; //channel_num 通道号,也就是需要读取的channel,针对battery thermal是LR_MUX1_BATT_THERM=48,正好匹配
                qcom,decimation = <0>;
                qcom,pre-div-channel-scaling = <0>;
                qcom,calibration-type = "ratiometric";
                qcom,scale-function = <1>; //adc_scale_fn的ID,也就是scale_type
                qcom,hw-settle-time = <2>;
                qcom,fast-avg-setup = <0>;
            };
       ->vadc_scale_fn的定义
        static struct qpnp_vadc_scale_fn vadc_scale_fn[] = {
            [SCALE_DEFAULT] = {qpnp_adc_scale_default},
            [SCALE_BATT_THERM] = {qpnp_adc_scale_batt_therm}, //battery thermal的scale函数qpnp_adc_scale_batt_therm@qpnp-adc-common.c
            [SCALE_PMIC_THERM] = {qpnp_adc_scale_pmic_therm},
            [SCALE_XOTHERM] = {qpnp_adc_tdkntcg_therm},
            [SCALE_THERM_100K_PULLUP] = {qpnp_adc_scale_therm_pu2},
            [SCALE_THERM_150K_PULLUP] = {qpnp_adc_scale_therm_pu1},
            [SCALE_QRD_BATT_THERM] = {qpnp_adc_scale_qrd_batt_therm},
        };          



estimate_ocv
clamp_soc_based_on_voltage_with_max_count
问题:
DMS01852397
qpnp_chg_idcmax_set 中算法和datasheet不一致?
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