/*
* Copyright (C) ST-Ericsson SA 2010
*
* 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>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/completion.h>
#include <linux/regulator/consumer.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/mfd/ab8500.h>
#include <linux/mfd/abx500.h>
#include <linux/mfd/ab8500/gpadc.h>
/*
* GPADC register offsets
* Bank : 0x0A
*/
#define AB8500_GPADC_CTRL1_REG 0x00
#define AB8500_GPADC_CTRL2_REG 0x01
#define AB8500_GPADC_CTRL3_REG 0x02
#define AB8500_GPADC_AUTO_TIMER_REG 0x03
#define AB8500_GPADC_STAT_REG 0x04
#define AB8500_GPADC_MANDATAL_REG 0x05
#define AB8500_GPADC_MANDATAH_REG 0x06
#define AB8500_GPADC_AUTODATAL_REG 0x07
#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
#define EN_GPADC 0x01
#define DIS_GPADC 0x00
#define SW_AVG_16 0x60
#define ADC_SW_CONV 0x04
#define EN_ICHAR 0x80
#define EN_BUF 0x40
#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
* @dev: pointer to the struct device
* @node: a list of AB8500 GPADCs, hence prepared for
reentrance
* @ab8500_gpadc_complete: pointer to the struct completion, to indicate
* the completion of gpadc conversion
* @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;
struct list_head node;
struct completion ab8500_gpadc_complete;
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);
/**
* ab8500_gpadc_get() - returns a reference to the primary AB8500 GPADC
* (i.e. the first GPADC in the instance list)
*/
struct ab8500_gpadc *ab8500_gpadc_get(char *name)
{
struct ab8500_gpadc *gpadc;
list_for_each_entry(gpadc, &ab8500_gpadc_list, node) {
if (!strcmp(name, dev_name(gpadc->dev)))
return gpadc;
}
return ERR_PTR(-ENOENT);
}
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.
*/
int ab8500_gpadc_convert(struct ab8500_gpadc *gpadc, u8 input)
{
int ret;
u16 data = 0;
int looplimit = 0;
u8 val, low_data, high_data;
if (!gpadc)
return -ENODEV;
mutex_lock(&gpadc->ab8500_gpadc_lock);
/* Enable VTVout LDO this is required for GPADC */
regulator_enable(gpadc->regu);
/* Check if ADC is not busy, lock and proceed */
do {
ret = abx500_get_register_interruptible(gpadc->dev,
AB8500_GPADC, AB8500_GPADC_STAT_REG, &val);
if (ret < 0)
goto out;
if (!(val & GPADC_BUSY))
break;
msleep(10);
} while (++looplimit < 10);
if (looplimit >= 10 && (val & GPADC_BUSY)) {
dev_err(gpadc->dev, "gpadc_conversion: GPADC busy");
ret = -EINVAL;
goto out;
}
/* Enable GPADC */
ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_GPADC, EN_GPADC);
if (ret < 0) {
dev_err(gpadc->dev, "gpadc_conversion: enable gpadc failed\n");
goto out;
}
/* Select the input source and set average samples to 16 */
ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
AB8500_GPADC_CTRL2_REG, (input | SW_AVG_16));
if (ret < 0) {
dev_err(gpadc->dev,
"gpadc_conversion: set avg samples failed\n");
goto out;
}
/*
* Enable ADC, buffering, select rising edge and enable ADC path
* charging current sense if it needed
*/
switch (input) {
case MAIN_CHARGER_C:
case USB_CHARGER_C:
ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
AB8500_GPADC, AB8500_GPADC_CTRL1_REG,
EN_BUF | EN_ICHAR,
EN_BUF | EN_ICHAR);
break;
default:
ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_BUF, EN_BUF);
break;
}
if (ret < 0) {
dev_err(gpadc->dev,
"gpadc_conversion: select falling edge failed\n");
goto out;
}
ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
AB8500_GPADC, AB8500_GPADC_CTRL1_REG, ADC_SW_CONV, ADC_SW_CONV);
if (ret < 0) {
dev_err(gpadc->dev,
"gpadc_conversion: start s/w conversion failed\n");
goto out;
}
/* wait for completion of conversion */
if (!wait_for_completion_timeout(&gpadc->ab8500_gpadc_complete, 2*HZ)) {
dev_err(gpadc->dev,
"timeout: didn't receive GPADC conversion interrupt\n");
ret = -EINVAL;
goto out;
}
/* Read the converted RAW data */
ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC,
AB8500_GPADC_MANDATAL_REG, &low_data);
if (ret < 0) {
dev_err(gpadc->dev, "gpadc_conversion: read low data failed\n");
goto out;
}
ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC,
AB8500_GPADC_MANDATAH_REG, &high_data);
if (ret < 0) {
dev_err(gpadc->dev,
"gpadc_conversion: read high data failed\n");
goto out;
}
data = (high_data << 8) | low_data;
/* Disable GPADC */
ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
AB8500_GPADC_CTRL1_REG, DIS_GPADC);
if (ret < 0) {
dev_err(gpadc->dev, "gpadc_conversion: disable gpadc failed\n");
goto out;
}
/* Disable VTVout LDO this is required for GPADC */
regulator_disable(gpadc->regu);
mutex_unlock(&gpadc->ab8500_gpadc_lock);
ret = ab8500_gpadc_ad_to_voltage(gpadc, input, data);
return ret;
out:
/*
* It has shown to be needed to turn off the GPADC if an error occurs,
* otherwise we might have problem when waiting for the busy bit in the
* GPADC status register to go low. In V1.1 there wait_for_completion
* seems to timeout when waiting for an interrupt.. Not seen in V2.0
*/
(void) abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
AB8500_GPADC_CTRL1_REG, DIS_GPADC);
regulator_disable(gpadc->regu);
mutex_unlock(&gpadc->ab8500_gpadc_lock);
dev_err(gpadc->dev,
"gpadc_conversion: Failed to AD convert channel %d\n", input);
return ret;
}
EXPORT_SYMBOL(ab8500_gpadc_convert);
/**
* ab8500_bm_gpswadcconvend_handler() - isr for s/w gpadc conversion completion
* @irq: irq number
* @data: pointer to the data passed during request irq
*
* This is a interrupt service routine for s/w gpadc conversion completion.
* Notifies the gpadc completion is completed and the converted raw value
* can be read from the registers.
* Returns IRQ status(IRQ_HANDLED)
*/
static irqreturn_t ab8500_bm_gpswadcconvend_handler(int irq, void *_gpadc)
{
struct ab8500_gpadc *gpadc = _gpadc;
complete(&gpadc->ab8500_gpadc_complete);
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;
struct ab8500_gpadc *gpadc;
gpadc = kzalloc(sizeof(struct ab8500_gpadc), GFP_KERNEL);
if (!gpadc) {
dev_err(&pdev->dev, "Error: No memory\n");
return -ENOMEM;
}
gpadc->irq = platform_get_irq_byname(pdev, "SW_CONV_END");
if (gpadc->irq < 0) {
dev_err(gpadc->dev, "failed to get platform irq-%d\n",
gpadc->irq);
ret = gpadc->irq;
goto fail;
}
gpadc->dev = &pdev->dev;
mutex_init(&gpadc->ab8500_gpadc_lock);
/* Initialize completion used to notify completion of conversion */
init_completion(&gpadc->ab8500_gpadc_complete);
/* Register interrupt - SwAdcComplete */
ret = request_threaded_irq(gpadc->irq, NULL,
ab8500_bm_gpswadcconvend_handler,
IRQF_NO_SUSPEND | IRQF_SHARED, "ab8500-gpadc", gpadc);
if (ret < 0) {
dev_err(gpadc->dev, "Failed to register interrupt, irq: %d\n",
gpadc->irq);
goto fail;
}
/* VTVout LDO used to power up ab8500-GPADC */
gpadc->regu = regulator_get(&pdev->dev, "vddadc");
if (IS_ERR(gpadc->regu)) {
ret = PTR_ERR(gpadc->regu);
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;
fail_irq:
free_irq(gpadc->irq, gpadc);
fail:
kfree(gpadc);
gpadc = NULL;
return ret;
}
static int __devexit ab8500_gpadc_remove(struct platform_device *pdev)
{
struct ab8500_gpadc *gpadc = platform_get_drvdata(pdev);
/* remove this gpadc entry from the list */
list_del(&gpadc->node);
/* remove interrupt - completion of Sw ADC conversion */
free_irq(gpadc->irq, gpadc);
/* disable VTVout LDO that is being used by GPADC */
regulator_put(gpadc->regu);
kfree(gpadc);
gpadc = NULL;
return 0;
}
static struct platform_driver ab8500_gpadc_driver = {
.probe = ab8500_gpadc_probe,
.remove = __devexit_p(ab8500_gpadc_remove),
.driver = {
.name = "ab8500-gpadc",
.owner = THIS_MODULE,
},
};
static int __init ab8500_gpadc_init(void)
{
return platform_driver_register(&ab8500_gpadc_driver);
}
static void __exit ab8500_gpadc_exit(void)
{
platform_driver_unregister(&ab8500_gpadc_driver);
}
subsys_initcall_sync(ab8500_gpadc_init);
module_exit(ab8500_gpadc_exit);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Arun R Murthy, Daniel Willerud, Johan Palsson");
MODULE_ALIAS("platform:ab8500_gpadc");
MODULE_DESCRIPTION("AB8500 GPADC driver");
