diff options
| -rw-r--r-- | drivers/mfd/ab8500-gpadc.c | 286 |
1 files changed, 281 insertions, 5 deletions
diff --git a/drivers/mfd/ab8500-gpadc.c b/drivers/mfd/ab8500-gpadc.c index b5b75b7..a70201a 100644 --- a/drivers/mfd/ab8500-gpadc.c +++ b/drivers/mfd/ab8500-gpadc.c @@ -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 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 + * 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"); |
