mfd: Calibrate ab8500 gpadc using OTP values
The GPADC found in the AB8500 needs to be calibrated to work properly. This is done by writing a number of special OTP (one-time-programmable) registers at production. This patch makes sure that these values are used to calibrate the returned value from the GPADC so that it is correct. Signed-off-by: Johan Palsson <johan.palsson@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This commit is contained in:
Johan Palsson
Samuel Ortiz
Родитель
633e0fa590
Коммит
586f3318ad
|
|
@ -4,6 +4,7 @@
|
|||
* License Terms: GNU General Public License v2
|
||||
* Author: Arun R Murthy <arun.murthy@stericsson.com>
|
||||
* Author: Daniel Willerud <daniel.willerud@stericsson.com>
|
||||
* Author: Johan Palsson <johan.palsson@stericsson.com>
|
||||
*/
|
||||
#include <linux/init.h>
|
||||
#include <linux/module.h>
|
||||
|
|
@ -36,6 +37,18 @@
|
|||
#define AB8500_GPADC_AUTODATAH_REG 0x08
|
||||
#define AB8500_GPADC_MUX_CTRL_REG 0x09
|
||||
|
||||
/*
|
||||
* OTP register offsets
|
||||
* Bank : 0x15
|
||||
*/
|
||||
#define AB8500_GPADC_CAL_1 0x0F
|
||||
#define AB8500_GPADC_CAL_2 0x10
|
||||
#define AB8500_GPADC_CAL_3 0x11
|
||||
#define AB8500_GPADC_CAL_4 0x12
|
||||
#define AB8500_GPADC_CAL_5 0x13
|
||||
#define AB8500_GPADC_CAL_6 0x14
|
||||
#define AB8500_GPADC_CAL_7 0x15
|
||||
|
||||
/* gpadc constants */
|
||||
#define EN_VINTCORE12 0x04
|
||||
#define EN_VTVOUT 0x02
|
||||
|
|
@ -47,8 +60,46 @@
|
|||
#define DIS_ZERO 0x00
|
||||
#define GPADC_BUSY 0x01
|
||||
|
||||
/* GPADC constants from AB8500 spec, UM0836 */
|
||||
#define ADC_RESOLUTION 1024
|
||||
#define ADC_CH_BTEMP_MIN 0
|
||||
#define ADC_CH_BTEMP_MAX 1350
|
||||
#define ADC_CH_DIETEMP_MIN 0
|
||||
#define ADC_CH_DIETEMP_MAX 1350
|
||||
#define ADC_CH_CHG_V_MIN 0
|
||||
#define ADC_CH_CHG_V_MAX 20030
|
||||
#define ADC_CH_ACCDET2_MIN 0
|
||||
#define ADC_CH_ACCDET2_MAX 2500
|
||||
#define ADC_CH_VBAT_MIN 2300
|
||||
#define ADC_CH_VBAT_MAX 4800
|
||||
#define ADC_CH_CHG_I_MIN 0
|
||||
#define ADC_CH_CHG_I_MAX 1500
|
||||
#define ADC_CH_BKBAT_MIN 0
|
||||
#define ADC_CH_BKBAT_MAX 3200
|
||||
|
||||
/* This is used to not lose precision when dividing to get gain and offset */
|
||||
#define CALIB_SCALE 1000
|
||||
|
||||
enum cal_channels {
|
||||
ADC_INPUT_VMAIN = 0,
|
||||
ADC_INPUT_BTEMP,
|
||||
ADC_INPUT_VBAT,
|
||||
NBR_CAL_INPUTS,
|
||||
};
|
||||
|
||||
/**
|
||||
* struct ab8500_gpadc - ab8500 GPADC device information
|
||||
* struct adc_cal_data - Table for storing gain and offset for the calibrated
|
||||
* ADC channels
|
||||
* @gain: Gain of the ADC channel
|
||||
* @offset: Offset of the ADC channel
|
||||
*/
|
||||
struct adc_cal_data {
|
||||
u64 gain;
|
||||
u64 offset;
|
||||
};
|
||||
|
||||
/**
|
||||
* struct ab8500_gpadc - AB8500 GPADC device information
|
||||
* @dev: pointer to the struct device
|
||||
* @node: a list of AB8500 GPADCs, hence prepared for
|
||||
reentrance
|
||||
|
|
@ -57,6 +108,7 @@
|
|||
* @ab8500_gpadc_lock: structure of type mutex
|
||||
* @regu: pointer to the struct regulator
|
||||
* @irq: interrupt number that is used by gpadc
|
||||
* @cal_data array of ADC calibration data structs
|
||||
*/
|
||||
struct ab8500_gpadc {
|
||||
struct device *dev;
|
||||
|
|
@ -65,6 +117,7 @@ struct ab8500_gpadc {
|
|||
struct mutex ab8500_gpadc_lock;
|
||||
struct regulator *regu;
|
||||
int irq;
|
||||
struct adc_cal_data cal_data[NBR_CAL_INPUTS];
|
||||
};
|
||||
|
||||
static LIST_HEAD(ab8500_gpadc_list);
|
||||
|
|
@ -86,13 +139,102 @@ struct ab8500_gpadc *ab8500_gpadc_get(char *name)
|
|||
}
|
||||
EXPORT_SYMBOL(ab8500_gpadc_get);
|
||||
|
||||
static int ab8500_gpadc_ad_to_voltage(struct ab8500_gpadc *gpadc, u8 input,
|
||||
int ad_value)
|
||||
{
|
||||
int res;
|
||||
|
||||
switch (input) {
|
||||
case MAIN_CHARGER_V:
|
||||
/* For some reason we don't have calibrated data */
|
||||
if (!gpadc->cal_data[ADC_INPUT_VMAIN].gain) {
|
||||
res = ADC_CH_CHG_V_MIN + (ADC_CH_CHG_V_MAX -
|
||||
ADC_CH_CHG_V_MIN) * ad_value /
|
||||
ADC_RESOLUTION;
|
||||
break;
|
||||
}
|
||||
/* Here we can use the calibrated data */
|
||||
res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_VMAIN].gain +
|
||||
gpadc->cal_data[ADC_INPUT_VMAIN].offset) / CALIB_SCALE;
|
||||
break;
|
||||
|
||||
case BAT_CTRL:
|
||||
case BTEMP_BALL:
|
||||
case ACC_DETECT1:
|
||||
case ADC_AUX1:
|
||||
case ADC_AUX2:
|
||||
/* For some reason we don't have calibrated data */
|
||||
if (!gpadc->cal_data[ADC_INPUT_BTEMP].gain) {
|
||||
res = ADC_CH_BTEMP_MIN + (ADC_CH_BTEMP_MAX -
|
||||
ADC_CH_BTEMP_MIN) * ad_value /
|
||||
ADC_RESOLUTION;
|
||||
break;
|
||||
}
|
||||
/* Here we can use the calibrated data */
|
||||
res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_BTEMP].gain +
|
||||
gpadc->cal_data[ADC_INPUT_BTEMP].offset) / CALIB_SCALE;
|
||||
break;
|
||||
|
||||
case MAIN_BAT_V:
|
||||
/* For some reason we don't have calibrated data */
|
||||
if (!gpadc->cal_data[ADC_INPUT_VBAT].gain) {
|
||||
res = ADC_CH_VBAT_MIN + (ADC_CH_VBAT_MAX -
|
||||
ADC_CH_VBAT_MIN) * ad_value /
|
||||
ADC_RESOLUTION;
|
||||
break;
|
||||
}
|
||||
/* Here we can use the calibrated data */
|
||||
res = (int) (ad_value * gpadc->cal_data[ADC_INPUT_VBAT].gain +
|
||||
gpadc->cal_data[ADC_INPUT_VBAT].offset) / CALIB_SCALE;
|
||||
break;
|
||||
|
||||
case DIE_TEMP:
|
||||
res = ADC_CH_DIETEMP_MIN +
|
||||
(ADC_CH_DIETEMP_MAX - ADC_CH_DIETEMP_MIN) * ad_value /
|
||||
ADC_RESOLUTION;
|
||||
break;
|
||||
|
||||
case ACC_DETECT2:
|
||||
res = ADC_CH_ACCDET2_MIN +
|
||||
(ADC_CH_ACCDET2_MAX - ADC_CH_ACCDET2_MIN) * ad_value /
|
||||
ADC_RESOLUTION;
|
||||
break;
|
||||
|
||||
case VBUS_V:
|
||||
res = ADC_CH_CHG_V_MIN +
|
||||
(ADC_CH_CHG_V_MAX - ADC_CH_CHG_V_MIN) * ad_value /
|
||||
ADC_RESOLUTION;
|
||||
break;
|
||||
|
||||
case MAIN_CHARGER_C:
|
||||
case USB_CHARGER_C:
|
||||
res = ADC_CH_CHG_I_MIN +
|
||||
(ADC_CH_CHG_I_MAX - ADC_CH_CHG_I_MIN) * ad_value /
|
||||
ADC_RESOLUTION;
|
||||
break;
|
||||
|
||||
case BK_BAT_V:
|
||||
res = ADC_CH_BKBAT_MIN +
|
||||
(ADC_CH_BKBAT_MAX - ADC_CH_BKBAT_MIN) * ad_value /
|
||||
ADC_RESOLUTION;
|
||||
break;
|
||||
|
||||
default:
|
||||
dev_err(gpadc->dev,
|
||||
"unknown channel, not possible to convert\n");
|
||||
res = -EINVAL;
|
||||
break;
|
||||
|
||||
}
|
||||
return res;
|
||||
}
|
||||
|
||||
/**
|
||||
* ab8500_gpadc_convert() - gpadc conversion
|
||||
* @input: analog input to be converted to digital data
|
||||
*
|
||||
* This function converts the selected analog i/p to digital
|
||||
* data. Thereafter calibration has to be made to obtain the
|
||||
* data in the required quantity measurement.
|
||||
* data.
|
||||
*/
|
||||
int ab8500_gpadc_convert(struct ab8500_gpadc *gpadc, u8 input)
|
||||
{
|
||||
|
|
@ -189,7 +331,8 @@ int ab8500_gpadc_convert(struct ab8500_gpadc *gpadc, u8 input)
|
|||
/* Disable VTVout LDO this is required for GPADC */
|
||||
regulator_disable(gpadc->regu);
|
||||
mutex_unlock(&gpadc->ab8500_gpadc_lock);
|
||||
return data;
|
||||
ret = ab8500_gpadc_ad_to_voltage(gpadc, input, data);
|
||||
return ret;
|
||||
|
||||
out:
|
||||
/*
|
||||
|
|
@ -227,6 +370,138 @@ static irqreturn_t ab8500_bm_gpswadcconvend_handler(int irq, void *_gpadc)
|
|||
return IRQ_HANDLED;
|
||||
}
|
||||
|
||||
static int otp_cal_regs[] = {
|
||||
AB8500_GPADC_CAL_1,
|
||||
AB8500_GPADC_CAL_2,
|
||||
AB8500_GPADC_CAL_3,
|
||||
AB8500_GPADC_CAL_4,
|
||||
AB8500_GPADC_CAL_5,
|
||||
AB8500_GPADC_CAL_6,
|
||||
AB8500_GPADC_CAL_7,
|
||||
};
|
||||
|
||||
static void ab8500_gpadc_read_calibration_data(struct ab8500_gpadc *gpadc)
|
||||
{
|
||||
int i;
|
||||
int ret[ARRAY_SIZE(otp_cal_regs)];
|
||||
u8 gpadc_cal[ARRAY_SIZE(otp_cal_regs)];
|
||||
|
||||
int vmain_high, vmain_low;
|
||||
int btemp_high, btemp_low;
|
||||
int vbat_high, vbat_low;
|
||||
|
||||
/* First we read all OTP registers and store the error code */
|
||||
for (i = 0; i < ARRAY_SIZE(otp_cal_regs); i++) {
|
||||
ret[i] = abx500_get_register_interruptible(gpadc->dev,
|
||||
AB8500_OTP_EMUL, otp_cal_regs[i], &gpadc_cal[i]);
|
||||
if (ret[i] < 0)
|
||||
dev_err(gpadc->dev, "%s: read otp reg 0x%02x failed\n",
|
||||
__func__, otp_cal_regs[i]);
|
||||
}
|
||||
|
||||
/*
|
||||
* The ADC calibration data is stored in OTP registers.
|
||||
* The layout of the calibration data is outlined below and a more
|
||||
* detailed description can be found in UM0836
|
||||
*
|
||||
* vm_h/l = vmain_high/low
|
||||
* bt_h/l = btemp_high/low
|
||||
* vb_h/l = vbat_high/low
|
||||
*
|
||||
* Data bits:
|
||||
* | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
|
||||
* |.......|.......|.......|.......|.......|.......|.......|.......
|
||||
* | | vm_h9 | vm_h8
|
||||
* |.......|.......|.......|.......|.......|.......|.......|.......
|
||||
* | | vm_h7 | vm_h6 | vm_h5 | vm_h4 | vm_h3 | vm_h2
|
||||
* |.......|.......|.......|.......|.......|.......|.......|.......
|
||||
* | vm_h1 | vm_h0 | vm_l4 | vm_l3 | vm_l2 | vm_l1 | vm_l0 | bt_h9
|
||||
* |.......|.......|.......|.......|.......|.......|.......|.......
|
||||
* | bt_h8 | bt_h7 | bt_h6 | bt_h5 | bt_h4 | bt_h3 | bt_h2 | bt_h1
|
||||
* |.......|.......|.......|.......|.......|.......|.......|.......
|
||||
* | bt_h0 | bt_l4 | bt_l3 | bt_l2 | bt_l1 | bt_l0 | vb_h9 | vb_h8
|
||||
* |.......|.......|.......|.......|.......|.......|.......|.......
|
||||
* | vb_h7 | vb_h6 | vb_h5 | vb_h4 | vb_h3 | vb_h2 | vb_h1 | vb_h0
|
||||
* |.......|.......|.......|.......|.......|.......|.......|.......
|
||||
* | vb_l5 | vb_l4 | vb_l3 | vb_l2 | vb_l1 | vb_l0 |
|
||||
* |.......|.......|.......|.......|.......|.......|.......|.......
|
||||
*
|
||||
*
|
||||
* Ideal output ADC codes corresponding to injected input voltages
|
||||
* during manufacturing is:
|
||||
*
|
||||
* vmain_high: Vin = 19500mV / ADC ideal code = 997
|
||||
* vmain_low: Vin = 315mV / ADC ideal code = 16
|
||||
* btemp_high: Vin = 1300mV / ADC ideal code = 985
|
||||
* btemp_low: Vin = 21mV / ADC ideal code = 16
|
||||
* vbat_high: Vin = 4700mV / ADC ideal code = 982
|
||||
* vbat_low: Vin = 2380mV / ADC ideal code = 33
|
||||
*/
|
||||
|
||||
/* Calculate gain and offset for VMAIN if all reads succeeded */
|
||||
if (!(ret[0] < 0 || ret[1] < 0 || ret[2] < 0)) {
|
||||
vmain_high = (((gpadc_cal[0] & 0x03) << 8) |
|
||||
((gpadc_cal[1] & 0x3F) << 2) |
|
||||
((gpadc_cal[2] & 0xC0) >> 6));
|
||||
|
||||
vmain_low = ((gpadc_cal[2] & 0x3E) >> 1);
|
||||
|
||||
gpadc->cal_data[ADC_INPUT_VMAIN].gain = CALIB_SCALE *
|
||||
(19500 - 315) / (vmain_high - vmain_low);
|
||||
|
||||
gpadc->cal_data[ADC_INPUT_VMAIN].offset = CALIB_SCALE * 19500 -
|
||||
(CALIB_SCALE * (19500 - 315) /
|
||||
(vmain_high - vmain_low)) * vmain_high;
|
||||
} else {
|
||||
gpadc->cal_data[ADC_INPUT_VMAIN].gain = 0;
|
||||
}
|
||||
|
||||
/* Calculate gain and offset for BTEMP if all reads succeeded */
|
||||
if (!(ret[2] < 0 || ret[3] < 0 || ret[4] < 0)) {
|
||||
btemp_high = (((gpadc_cal[2] & 0x01) << 9) |
|
||||
(gpadc_cal[3] << 1) |
|
||||
((gpadc_cal[4] & 0x80) >> 7));
|
||||
|
||||
btemp_low = ((gpadc_cal[4] & 0x7C) >> 2);
|
||||
|
||||
gpadc->cal_data[ADC_INPUT_BTEMP].gain =
|
||||
CALIB_SCALE * (1300 - 21) / (btemp_high - btemp_low);
|
||||
|
||||
gpadc->cal_data[ADC_INPUT_BTEMP].offset = CALIB_SCALE * 1300 -
|
||||
(CALIB_SCALE * (1300 - 21) /
|
||||
(btemp_high - btemp_low)) * btemp_high;
|
||||
} else {
|
||||
gpadc->cal_data[ADC_INPUT_BTEMP].gain = 0;
|
||||
}
|
||||
|
||||
/* Calculate gain and offset for VBAT if all reads succeeded */
|
||||
if (!(ret[4] < 0 || ret[5] < 0 || ret[6] < 0)) {
|
||||
vbat_high = (((gpadc_cal[4] & 0x03) << 8) | gpadc_cal[5]);
|
||||
vbat_low = ((gpadc_cal[6] & 0xFC) >> 2);
|
||||
|
||||
gpadc->cal_data[ADC_INPUT_VBAT].gain = CALIB_SCALE *
|
||||
(4700 - 2380) / (vbat_high - vbat_low);
|
||||
|
||||
gpadc->cal_data[ADC_INPUT_VBAT].offset = CALIB_SCALE * 4700 -
|
||||
(CALIB_SCALE * (4700 - 2380) /
|
||||
(vbat_high - vbat_low)) * vbat_high;
|
||||
} else {
|
||||
gpadc->cal_data[ADC_INPUT_VBAT].gain = 0;
|
||||
}
|
||||
|
||||
dev_dbg(gpadc->dev, "VMAIN gain %llu offset %llu\n",
|
||||
gpadc->cal_data[ADC_INPUT_VMAIN].gain,
|
||||
gpadc->cal_data[ADC_INPUT_VMAIN].offset);
|
||||
|
||||
dev_dbg(gpadc->dev, "BTEMP gain %llu offset %llu\n",
|
||||
gpadc->cal_data[ADC_INPUT_BTEMP].gain,
|
||||
gpadc->cal_data[ADC_INPUT_BTEMP].offset);
|
||||
|
||||
dev_dbg(gpadc->dev, "VBAT gain %llu offset %llu\n",
|
||||
gpadc->cal_data[ADC_INPUT_VBAT].gain,
|
||||
gpadc->cal_data[ADC_INPUT_VBAT].offset);
|
||||
}
|
||||
|
||||
static int __devinit ab8500_gpadc_probe(struct platform_device *pdev)
|
||||
{
|
||||
int ret = 0;
|
||||
|
|
@ -269,6 +544,7 @@ static int __devinit ab8500_gpadc_probe(struct platform_device *pdev)
|
|||
dev_err(gpadc->dev, "failed to get vtvout LDO\n");
|
||||
goto fail_irq;
|
||||
}
|
||||
ab8500_gpadc_read_calibration_data(gpadc);
|
||||
list_add_tail(&gpadc->node, &ab8500_gpadc_list);
|
||||
dev_dbg(gpadc->dev, "probe success\n");
|
||||
return 0;
|
||||
|
|
@ -318,6 +594,6 @@ subsys_initcall_sync(ab8500_gpadc_init);
|
|||
module_exit(ab8500_gpadc_exit);
|
||||
|
||||
MODULE_LICENSE("GPL v2");
|
||||
MODULE_AUTHOR("Arun R Murthy, Daniel Willerud");
|
||||
MODULE_AUTHOR("Arun R Murthy, Daniel Willerud, Johan Palsson");
|
||||
MODULE_ALIAS("platform:ab8500_gpadc");
|
||||
MODULE_DESCRIPTION("AB8500 GPADC driver");
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче