高通QCOM 8610平台电量计算

一： SOC（荷电状态）计算方法

公式：

SOC = RUC / (FCC-UUC)

名词：

二：各参数计算方法：

1.FCC：根据电池温度temp通过查找表（lut）来计算

static int calculate_fcc(struct qpnp_bms_chip *chip, int batt_temp) 
{ 
	int fcc_uah; 
	 
	if (chip->adjusted_fcc_temp_lut == NULL) { // log显示，没有对温度lut进行修正； 
		/* interpolate_fcc returns a mv value. */ 
		fcc_uah = interpolate_fcc(chip->fcc_temp_lut, 
		batt_temp) * 1000;  // 不修正直接返回对应温度的FCC值 
		printk("fcc = %d uAh\n", fcc_uah); 
		return fcc_uah; 
	} else { 
		return 1000 * interpolate_fcc(chip->adjusted_fcc_temp_lut, 
		batt_temp); 
	} 
} 

2. RC: 依赖ocv，通过ocv计算；单位uAh

/* calculate remaining charge at the time of ocv */ 
static int calculate_ocv_charge(struct qpnp_bms_chip *chip, 
		struct raw_soc_params *raw, 
		int fcc_uah) 
{ 
	int  ocv_uv, pc; 
	// RAW - 存在pm？PM里读出来的未经修正的原始数据？ 
	// read_soc_params_raw -> qpnp_read_wrapper(chip, (u8 *)&raw->last_good_ocv_raw, 
	// chip->base + BMS1_OCV_FOR_SOC_DATA0, 2); 
	ocv_uv = raw->last_good_ocv_uv; // 1. 上次关机时存储的ocv；2. 电池新插入时会更新该值；3. 模拟电池新插入，手动更新：chip->insertion_ocv_uv;最终会更新raw->last_good_ocv_uv； 
	pc = calculate_pc(chip, ocv_uv, chip->last_ocv_temp); // 上次ocv占FCC的百分比，受温度影响 
	printk("ocv_uv = %d pc = %d\n", ocv_uv, pc); 
	return (fcc_uah * pc) / 100; 
} 
 
static int calculate_pc(struct qpnp_bms_chip *chip, int ocv_uv, 
		int batt_temp) 
{ 
	int pc; 
	 
	pc = interpolate_pc(chip->pc_temp_ocv_lut, 
	batt_temp / 10, ocv_uv / 1000); // 根据lut查找百分比 
	printk("pc = %u %% for ocv = %d uv batt_temp = %d\n", 
	pc, ocv_uv, batt_temp); 
	/* Multiply the initial FCC value by the scale factor. */ 
	return pc; 
} 

有时开机时的ocv和关机时的ocv（raw->last_good_ocv_raw?）差距太大就明显影响百分比计算了；

所以就需要做修正了；

3、CC：将bms电量计读值转换成uAh，coulomb counter有两种，shadow型不知道具体含义，不知是否和80x86里的影子寄存器是否为相同设计？：

/* Coulomb counter data */ 
#define BMS1_CC_DATA0 0x8A 
/* Shadow Coulomb counter data */ 
#define BMS1_SW_CC_DATA0 0xA8 
/** 
 * calculate_cc() - converts a hardware coulomb counter reading into uah 
 * @chip: the bms chip pointer 
 * @cc: the cc reading from bms h/w 
 * @cc_type: calcualte cc from regular or shadow coulomb counter 
 * @clear_cc: whether this function should clear the hardware counter 
 * after reading 
 * 
 * Converts the 64 bit hardware coulomb counter into microamp-hour by taking 
 * into account hardware resolution and adc errors. 
 * 
 * Return: the coulomb counter based charge in uAh (micro-amp hour) 
 */ 
static int calculate_cc(struct qpnp_bms_chip *chip, int64_t cc, 
		int cc_type, int clear_cc) 
{ 
	struct qpnp_iadc_calib calibration; 
	struct qpnp_vadc_result result; 
	int64_t cc_voltage_uv, cc_pvh, cc_uah, *software_counter; 
	int rc; 
	 
	// chip->software_shdw_cc_uah == 0; chip->software_cc_uah == 0; 
	software_counter = cc_type == SHDW_CC ? 
	&chip->software_shdw_cc_uah : &chip->software_cc_uah; 
	rc = qpnp_vadc_read(chip->vadc_dev, DIE_TEMP, &result); 
	if (rc) { 
		pr_err("could not read pmic die temperature: %d\n", rc); 
		return *software_counter; 
	} 
	 
	qpnp_iadc_get_gain_and_offset(chip->iadc_dev, &calibration); // 获得平台相关的增益修正参数，msm8610，msm8912； 
	printk("%scc = %lld, die_temp = %lld\n", 
	cc_type == SHDW_CC ? "shdw_" : "", 
	cc, result.physical); 
	cc_voltage_uv = cc_reading_to_uv(cc); 
	cc_voltage_uv = cc_adjust_for_gain(cc_voltage_uv, 
	calibration.gain_raw 
	- calibration.offset_raw); 
	cc_pvh = cc_uv_to_pvh(cc_voltage_uv);  // 为减小cc的精度损失； 
	cc_uah = div_s64(cc_pvh, chip->r_sense_uohm); // i = u / r；算出cc电流 
	rc = qpnp_iadc_comp_result(chip->iadc_dev, &cc_uah); // 根据QPNP不同版本ID，比如PM8110：QPNP_IADC_REV_ID_8110_1_0,做增益补偿 
	if (rc) 
	printk("error compensation failed: %d\n", rc); 
	if (clear_cc == RESET) {  //1. calculate_state_of_charge -> calculate_soc_params中有RESET调用；
							// 2. load_shutdown_data（probe获取上次关机时的一些参数，比如ocv） -> recalculate_raw_soc -> recalculate_soc ->calculate_soc_params有调用（先cc、后shadow_cc