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linux/drivers/iio/adc/qcom-spmi-vadc.c
Ivan T. Ivanov 937125aca0 iio: adc: spmi-vadc: Fix overflow in output value normalization 
With 'dx' equal to 0.625V and 15 bit ADC, calculations overflow
when difference against GND is ~20% of the ADC range. Fix this.

Signed-off-by: Ivan T. Ivanov <ivan.ivanov@linaro.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-04-18 17:40:04 +01:00

1018 lines
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/*
* Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/bitops.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/iio/iio.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/math64.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/log2.h>
#include <dt-bindings/iio/qcom,spmi-vadc.h>
/* VADC register and bit definitions */
#define VADC_REVISION2 0x1
#define VADC_REVISION2_SUPPORTED_VADC 1
#define VADC_PERPH_TYPE 0x4
#define VADC_PERPH_TYPE_ADC 8
#define VADC_PERPH_SUBTYPE 0x5
#define VADC_PERPH_SUBTYPE_VADC 1
#define VADC_STATUS1 0x8
#define VADC_STATUS1_OP_MODE 4
#define VADC_STATUS1_REQ_STS BIT(1)
#define VADC_STATUS1_EOC BIT(0)
#define VADC_STATUS1_REQ_STS_EOC_MASK 0x3
#define VADC_MODE_CTL 0x40
#define VADC_OP_MODE_SHIFT 3
#define VADC_OP_MODE_NORMAL 0
#define VADC_AMUX_TRIM_EN BIT(1)
#define VADC_ADC_TRIM_EN BIT(0)
#define VADC_EN_CTL1 0x46
#define VADC_EN_CTL1_SET BIT(7)
#define VADC_ADC_CH_SEL_CTL 0x48
#define VADC_ADC_DIG_PARAM 0x50
#define VADC_ADC_DIG_DEC_RATIO_SEL_SHIFT 2
#define VADC_HW_SETTLE_DELAY 0x51
#define VADC_CONV_REQ 0x52
#define VADC_CONV_REQ_SET BIT(7)
#define VADC_FAST_AVG_CTL 0x5a
#define VADC_FAST_AVG_EN 0x5b
#define VADC_FAST_AVG_EN_SET BIT(7)
#define VADC_ACCESS 0xd0
#define VADC_ACCESS_DATA 0xa5
#define VADC_PERH_RESET_CTL3 0xda
#define VADC_FOLLOW_WARM_RB BIT(2)
#define VADC_DATA 0x60 /* 16 bits */
#define VADC_CONV_TIME_MIN_US 2000
#define VADC_CONV_TIME_MAX_US 2100
/* Min ADC code represents 0V */
#define VADC_MIN_ADC_CODE 0x6000
/* Max ADC code represents full-scale range of 1.8V */
#define VADC_MAX_ADC_CODE 0xa800
#define VADC_ABSOLUTE_RANGE_UV 625000
#define VADC_RATIOMETRIC_RANGE_UV 1800000
#define VADC_DEF_PRESCALING 0 /* 1:1 */
#define VADC_DEF_DECIMATION 0 /* 512 */
#define VADC_DEF_HW_SETTLE_TIME 0 /* 0 us */
#define VADC_DEF_AVG_SAMPLES 0 /* 1 sample */
#define VADC_DEF_CALIB_TYPE VADC_CALIB_ABSOLUTE
#define VADC_DECIMATION_MIN 512
#define VADC_DECIMATION_MAX 4096
#define VADC_HW_SETTLE_DELAY_MAX 10000
#define VADC_AVG_SAMPLES_MAX 512
#define KELVINMIL_CELSIUSMIL 273150
#define VADC_CHAN_MIN VADC_USBIN
#define VADC_CHAN_MAX VADC_LR_MUX3_BUF_PU1_PU2_XO_THERM
/*
* VADC_CALIB_ABSOLUTE: uses the 625mV and 1.25V as reference channels.
* VADC_CALIB_RATIOMETRIC: uses the reference voltage (1.8V) and GND for
* calibration.
*/
enum vadc_calibration {
VADC_CALIB_ABSOLUTE = 0,
VADC_CALIB_RATIOMETRIC
};
/**
* struct vadc_linear_graph - Represent ADC characteristics.
* @dy: numerator slope to calculate the gain.
* @dx: denominator slope to calculate the gain.
* @gnd: A/D word of the ground reference used for the channel.
*
* Each ADC device has different offset and gain parameters which are
* computed to calibrate the device.
*/
struct vadc_linear_graph {
s32 dy;
s32 dx;
s32 gnd;
};
/**
* struct vadc_prescale_ratio - Represent scaling ratio for ADC input.
* @num: the inverse numerator of the gain applied to the input channel.
* @den: the inverse denominator of the gain applied to the input channel.
*/
struct vadc_prescale_ratio {
u32 num;
u32 den;
};
/**
* struct vadc_channel_prop - VADC channel property.
* @channel: channel number, refer to the channel list.
* @calibration: calibration type.
* @decimation: sampling rate supported for the channel.
* @prescale: channel scaling performed on the input signal.
* @hw_settle_time: the time between AMUX being configured and the
* start of conversion.
* @avg_samples: ability to provide single result from the ADC
* that is an average of multiple measurements.
*/
struct vadc_channel_prop {
unsigned int channel;
enum vadc_calibration calibration;
unsigned int decimation;
unsigned int prescale;
unsigned int hw_settle_time;
unsigned int avg_samples;
};
/**
* struct vadc_priv - VADC private structure.
* @regmap: pointer to struct regmap.
* @dev: pointer to struct device.
* @base: base address for the ADC peripheral.
* @nchannels: number of VADC channels.
* @chan_props: array of VADC channel properties.
* @iio_chans: array of IIO channels specification.
* @are_ref_measured: are reference points measured.
* @poll_eoc: use polling instead of interrupt.
* @complete: VADC result notification after interrupt is received.
* @graph: store parameters for calibration.
* @lock: ADC lock for access to the peripheral.
*/
struct vadc_priv {
struct regmap *regmap;
struct device *dev;
u16 base;
unsigned int nchannels;
struct vadc_channel_prop *chan_props;
struct iio_chan_spec *iio_chans;
bool are_ref_measured;
bool poll_eoc;
struct completion complete;
struct vadc_linear_graph graph[2];
struct mutex lock;
};
static const struct vadc_prescale_ratio vadc_prescale_ratios[] = {
{.num = 1, .den = 1},
{.num = 1, .den = 3},
{.num = 1, .den = 4},
{.num = 1, .den = 6},
{.num = 1, .den = 20},
{.num = 1, .den = 8},
{.num = 10, .den = 81},
{.num = 1, .den = 10}
};
static int vadc_read(struct vadc_priv *vadc, u16 offset, u8 *data)
{
return regmap_bulk_read(vadc->regmap, vadc->base + offset, data, 1);
}
static int vadc_write(struct vadc_priv *vadc, u16 offset, u8 data)
{
return regmap_write(vadc->regmap, vadc->base + offset, data);
}
static int vadc_reset(struct vadc_priv *vadc)
{
u8 data;
int ret;
ret = vadc_write(vadc, VADC_ACCESS, VADC_ACCESS_DATA);
if (ret)
return ret;
ret = vadc_read(vadc, VADC_PERH_RESET_CTL3, &data);
if (ret)
return ret;
ret = vadc_write(vadc, VADC_ACCESS, VADC_ACCESS_DATA);
if (ret)
return ret;
data |= VADC_FOLLOW_WARM_RB;
return vadc_write(vadc, VADC_PERH_RESET_CTL3, data);
}
static int vadc_set_state(struct vadc_priv *vadc, bool state)
{
return vadc_write(vadc, VADC_EN_CTL1, state ? VADC_EN_CTL1_SET : 0);
}
static void vadc_show_status(struct vadc_priv *vadc)
{
u8 mode, sta1, chan, dig, en, req;
int ret;
ret = vadc_read(vadc, VADC_MODE_CTL, &mode);
if (ret)
return;
ret = vadc_read(vadc, VADC_ADC_DIG_PARAM, &dig);
if (ret)
return;
ret = vadc_read(vadc, VADC_ADC_CH_SEL_CTL, &chan);
if (ret)
return;
ret = vadc_read(vadc, VADC_CONV_REQ, &req);
if (ret)
return;
ret = vadc_read(vadc, VADC_STATUS1, &sta1);
if (ret)
return;
ret = vadc_read(vadc, VADC_EN_CTL1, &en);
if (ret)
return;
dev_err(vadc->dev,
"mode:%02x en:%02x chan:%02x dig:%02x req:%02x sta1:%02x\n",
mode, en, chan, dig, req, sta1);
}
static int vadc_configure(struct vadc_priv *vadc,
struct vadc_channel_prop *prop)
{
u8 decimation, mode_ctrl;
int ret;
/* Mode selection */
mode_ctrl = (VADC_OP_MODE_NORMAL << VADC_OP_MODE_SHIFT) |
VADC_ADC_TRIM_EN | VADC_AMUX_TRIM_EN;
ret = vadc_write(vadc, VADC_MODE_CTL, mode_ctrl);
if (ret)
return ret;
/* Channel selection */
ret = vadc_write(vadc, VADC_ADC_CH_SEL_CTL, prop->channel);
if (ret)
return ret;
/* Digital parameter setup */
decimation = prop->decimation << VADC_ADC_DIG_DEC_RATIO_SEL_SHIFT;
ret = vadc_write(vadc, VADC_ADC_DIG_PARAM, decimation);
if (ret)
return ret;
/* HW settle time delay */
ret = vadc_write(vadc, VADC_HW_SETTLE_DELAY, prop->hw_settle_time);
if (ret)
return ret;
ret = vadc_write(vadc, VADC_FAST_AVG_CTL, prop->avg_samples);
if (ret)
return ret;
if (prop->avg_samples)
ret = vadc_write(vadc, VADC_FAST_AVG_EN, VADC_FAST_AVG_EN_SET);
else
ret = vadc_write(vadc, VADC_FAST_AVG_EN, 0);
return ret;
}
static int vadc_poll_wait_eoc(struct vadc_priv *vadc, unsigned int interval_us)
{
unsigned int count, retry;
u8 sta1;
int ret;
retry = interval_us / VADC_CONV_TIME_MIN_US;
for (count = 0; count < retry; count++) {
ret = vadc_read(vadc, VADC_STATUS1, &sta1);
if (ret)
return ret;
sta1 &= VADC_STATUS1_REQ_STS_EOC_MASK;
if (sta1 == VADC_STATUS1_EOC)
return 0;
usleep_range(VADC_CONV_TIME_MIN_US, VADC_CONV_TIME_MAX_US);
}
vadc_show_status(vadc);
return -ETIMEDOUT;
}
static int vadc_read_result(struct vadc_priv *vadc, u16 *data)
{
int ret;
ret = regmap_bulk_read(vadc->regmap, vadc->base + VADC_DATA, data, 2);
if (ret)
return ret;
*data = clamp_t(u16, *data, VADC_MIN_ADC_CODE, VADC_MAX_ADC_CODE);
return 0;
}
static struct vadc_channel_prop *vadc_get_channel(struct vadc_priv *vadc,
unsigned int num)
{
unsigned int i;
for (i = 0; i < vadc->nchannels; i++)
if (vadc->chan_props[i].channel == num)
return &vadc->chan_props[i];
dev_dbg(vadc->dev, "no such channel %02x\n", num);
return NULL;
}
static int vadc_do_conversion(struct vadc_priv *vadc,
struct vadc_channel_prop *prop, u16 *data)
{
unsigned int timeout;
int ret;
mutex_lock(&vadc->lock);
ret = vadc_configure(vadc, prop);
if (ret)
goto unlock;
if (!vadc->poll_eoc)
reinit_completion(&vadc->complete);
ret = vadc_set_state(vadc, true);
if (ret)
goto unlock;
ret = vadc_write(vadc, VADC_CONV_REQ, VADC_CONV_REQ_SET);
if (ret)
goto err_disable;
timeout = BIT(prop->avg_samples) * VADC_CONV_TIME_MIN_US * 2;
if (vadc->poll_eoc) {
ret = vadc_poll_wait_eoc(vadc, timeout);
} else {
ret = wait_for_completion_timeout(&vadc->complete, timeout);
if (!ret) {
ret = -ETIMEDOUT;
goto err_disable;
}
/* Double check conversion status */
ret = vadc_poll_wait_eoc(vadc, VADC_CONV_TIME_MIN_US);
if (ret)
goto err_disable;
}
ret = vadc_read_result(vadc, data);
err_disable:
vadc_set_state(vadc, false);
if (ret)
dev_err(vadc->dev, "conversion failed\n");
unlock:
mutex_unlock(&vadc->lock);
return ret;
}
static int vadc_measure_ref_points(struct vadc_priv *vadc)
{
struct vadc_channel_prop *prop;
u16 read_1, read_2;
int ret;
vadc->graph[VADC_CALIB_RATIOMETRIC].dx = VADC_RATIOMETRIC_RANGE_UV;
vadc->graph[VADC_CALIB_ABSOLUTE].dx = VADC_ABSOLUTE_RANGE_UV;
prop = vadc_get_channel(vadc, VADC_REF_1250MV);
ret = vadc_do_conversion(vadc, prop, &read_1);
if (ret)
goto err;
/* Try with buffered 625mV channel first */
prop = vadc_get_channel(vadc, VADC_SPARE1);
if (!prop)
prop = vadc_get_channel(vadc, VADC_REF_625MV);
ret = vadc_do_conversion(vadc, prop, &read_2);
if (ret)
goto err;
if (read_1 == read_2) {
ret = -EINVAL;
goto err;
}
vadc->graph[VADC_CALIB_ABSOLUTE].dy = read_1 - read_2;
vadc->graph[VADC_CALIB_ABSOLUTE].gnd = read_2;
/* Ratiometric calibration */
prop = vadc_get_channel(vadc, VADC_VDD_VADC);
ret = vadc_do_conversion(vadc, prop, &read_1);
if (ret)
goto err;
prop = vadc_get_channel(vadc, VADC_GND_REF);
ret = vadc_do_conversion(vadc, prop, &read_2);
if (ret)
goto err;
if (read_1 == read_2) {
ret = -EINVAL;
goto err;
}
vadc->graph[VADC_CALIB_RATIOMETRIC].dy = read_1 - read_2;
vadc->graph[VADC_CALIB_RATIOMETRIC].gnd = read_2;
err:
if (ret)
dev_err(vadc->dev, "measure reference points failed\n");
return ret;
}
static s32 vadc_calibrate(struct vadc_priv *vadc,
const struct vadc_channel_prop *prop, u16 adc_code)
{
const struct vadc_prescale_ratio *prescale;
s64 voltage;
voltage = adc_code - vadc->graph[prop->calibration].gnd;
voltage *= vadc->graph[prop->calibration].dx;
voltage = div64_s64(voltage, vadc->graph[prop->calibration].dy);
if (prop->calibration == VADC_CALIB_ABSOLUTE)
voltage += vadc->graph[prop->calibration].dx;
if (voltage < 0)
voltage = 0;
prescale = &vadc_prescale_ratios[prop->prescale];
voltage = voltage * prescale->den;
return div64_s64(voltage, prescale->num);
}
static int vadc_decimation_from_dt(u32 value)
{
if (!is_power_of_2(value) || value < VADC_DECIMATION_MIN ||
value > VADC_DECIMATION_MAX)
return -EINVAL;
return __ffs64(value / VADC_DECIMATION_MIN);
}
static int vadc_prescaling_from_dt(u32 num, u32 den)
{
unsigned int pre;
for (pre = 0; pre < ARRAY_SIZE(vadc_prescale_ratios); pre++)
if (vadc_prescale_ratios[pre].num == num &&
vadc_prescale_ratios[pre].den == den)
break;
if (pre == ARRAY_SIZE(vadc_prescale_ratios))
return -EINVAL;
return pre;
}
static int vadc_hw_settle_time_from_dt(u32 value)
{
if ((value <= 1000 && value % 100) || (value > 1000 && value % 2000))
return -EINVAL;
if (value <= 1000)
value /= 100;
else
value = value / 2000 + 10;
return value;
}
static int vadc_avg_samples_from_dt(u32 value)
{
if (!is_power_of_2(value) || value > VADC_AVG_SAMPLES_MAX)
return -EINVAL;
return __ffs64(value);
}
static int vadc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val, int *val2,
long mask)
{
struct vadc_priv *vadc = iio_priv(indio_dev);
struct vadc_channel_prop *prop;
u16 adc_code;
int ret;
switch (mask) {
case IIO_CHAN_INFO_PROCESSED:
prop = &vadc->chan_props[chan->address];
ret = vadc_do_conversion(vadc, prop, &adc_code);
if (ret)
break;
*val = vadc_calibrate(vadc, prop, adc_code);
/* 2mV/K, return milli Celsius */
*val /= 2;
*val -= KELVINMIL_CELSIUSMIL;
return IIO_VAL_INT;
case IIO_CHAN_INFO_RAW:
prop = &vadc->chan_props[chan->address];
ret = vadc_do_conversion(vadc, prop, &adc_code);
if (ret)
break;
*val = vadc_calibrate(vadc, prop, adc_code);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 0;
*val2 = 1000;
return IIO_VAL_INT_PLUS_MICRO;
default:
ret = -EINVAL;
break;
}
return ret;
}
static int vadc_of_xlate(struct iio_dev *indio_dev,
const struct of_phandle_args *iiospec)
{
struct vadc_priv *vadc = iio_priv(indio_dev);
unsigned int i;
for (i = 0; i < vadc->nchannels; i++)
if (vadc->iio_chans[i].channel == iiospec->args[0])
return i;
return -EINVAL;
}
static const struct iio_info vadc_info = {
.read_raw = vadc_read_raw,
.of_xlate = vadc_of_xlate,
.driver_module = THIS_MODULE,
};
struct vadc_channels {
const char *datasheet_name;
unsigned int prescale_index;
enum iio_chan_type type;
long info_mask;
};
#define VADC_CHAN(_dname, _type, _mask, _pre) \
[VADC_##_dname] = { \
.datasheet_name = __stringify(_dname), \
.prescale_index = _pre, \
.type = _type, \
.info_mask = _mask \
}, \
#define VADC_CHAN_TEMP(_dname, _pre) \
VADC_CHAN(_dname, IIO_TEMP, BIT(IIO_CHAN_INFO_PROCESSED), _pre) \
#define VADC_CHAN_VOLT(_dname, _pre) \
VADC_CHAN(_dname, IIO_VOLTAGE, \
BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), \
_pre) \
/*
* The array represents all possible ADC channels found in the supported PMICs.
* Every index in the array is equal to the channel number per datasheet. The
* gaps in the array should be treated as reserved channels.
*/
static const struct vadc_channels vadc_chans[] = {
VADC_CHAN_VOLT(USBIN, 4)
VADC_CHAN_VOLT(DCIN, 4)
VADC_CHAN_VOLT(VCHG_SNS, 3)
VADC_CHAN_VOLT(SPARE1_03, 1)
VADC_CHAN_VOLT(USB_ID_MV, 1)
VADC_CHAN_VOLT(VCOIN, 1)
VADC_CHAN_VOLT(VBAT_SNS, 1)
VADC_CHAN_VOLT(VSYS, 1)
VADC_CHAN_TEMP(DIE_TEMP, 0)
VADC_CHAN_VOLT(REF_625MV, 0)
VADC_CHAN_VOLT(REF_1250MV, 0)
VADC_CHAN_VOLT(CHG_TEMP, 0)
VADC_CHAN_VOLT(SPARE1, 0)
VADC_CHAN_VOLT(SPARE2, 0)
VADC_CHAN_VOLT(GND_REF, 0)
VADC_CHAN_VOLT(VDD_VADC, 0)
VADC_CHAN_VOLT(P_MUX1_1_1, 0)
VADC_CHAN_VOLT(P_MUX2_1_1, 0)
VADC_CHAN_VOLT(P_MUX3_1_1, 0)
VADC_CHAN_VOLT(P_MUX4_1_1, 0)
VADC_CHAN_VOLT(P_MUX5_1_1, 0)
VADC_CHAN_VOLT(P_MUX6_1_1, 0)
VADC_CHAN_VOLT(P_MUX7_1_1, 0)
VADC_CHAN_VOLT(P_MUX8_1_1, 0)
VADC_CHAN_VOLT(P_MUX9_1_1, 0)
VADC_CHAN_VOLT(P_MUX10_1_1, 0)
VADC_CHAN_VOLT(P_MUX11_1_1, 0)
VADC_CHAN_VOLT(P_MUX12_1_1, 0)
VADC_CHAN_VOLT(P_MUX13_1_1, 0)
VADC_CHAN_VOLT(P_MUX14_1_1, 0)
VADC_CHAN_VOLT(P_MUX15_1_1, 0)
VADC_CHAN_VOLT(P_MUX16_1_1, 0)
VADC_CHAN_VOLT(P_MUX1_1_3, 1)
VADC_CHAN_VOLT(P_MUX2_1_3, 1)
VADC_CHAN_VOLT(P_MUX3_1_3, 1)
VADC_CHAN_VOLT(P_MUX4_1_3, 1)
VADC_CHAN_VOLT(P_MUX5_1_3, 1)
VADC_CHAN_VOLT(P_MUX6_1_3, 1)
VADC_CHAN_VOLT(P_MUX7_1_3, 1)
VADC_CHAN_VOLT(P_MUX8_1_3, 1)
VADC_CHAN_VOLT(P_MUX9_1_3, 1)
VADC_CHAN_VOLT(P_MUX10_1_3, 1)
VADC_CHAN_VOLT(P_MUX11_1_3, 1)
VADC_CHAN_VOLT(P_MUX12_1_3, 1)
VADC_CHAN_VOLT(P_MUX13_1_3, 1)
VADC_CHAN_VOLT(P_MUX14_1_3, 1)
VADC_CHAN_VOLT(P_MUX15_1_3, 1)
VADC_CHAN_VOLT(P_MUX16_1_3, 1)
VADC_CHAN_VOLT(LR_MUX1_BAT_THERM, 0)
VADC_CHAN_VOLT(LR_MUX2_BAT_ID, 0)
VADC_CHAN_VOLT(LR_MUX3_XO_THERM, 0)
VADC_CHAN_VOLT(LR_MUX4_AMUX_THM1, 0)
VADC_CHAN_VOLT(LR_MUX5_AMUX_THM2, 0)
VADC_CHAN_VOLT(LR_MUX6_AMUX_THM3, 0)
VADC_CHAN_VOLT(LR_MUX7_HW_ID, 0)
VADC_CHAN_VOLT(LR_MUX8_AMUX_THM4, 0)
VADC_CHAN_VOLT(LR_MUX9_AMUX_THM5, 0)
VADC_CHAN_VOLT(LR_MUX10_USB_ID, 0)
VADC_CHAN_VOLT(AMUX_PU1, 0)
VADC_CHAN_VOLT(AMUX_PU2, 0)
VADC_CHAN_VOLT(LR_MUX3_BUF_XO_THERM, 0)
VADC_CHAN_VOLT(LR_MUX1_PU1_BAT_THERM, 0)
VADC_CHAN_VOLT(LR_MUX2_PU1_BAT_ID, 0)
VADC_CHAN_VOLT(LR_MUX3_PU1_XO_THERM, 0)
VADC_CHAN_VOLT(LR_MUX4_PU1_AMUX_THM1, 0)
VADC_CHAN_VOLT(LR_MUX5_PU1_AMUX_THM2, 0)
VADC_CHAN_VOLT(LR_MUX6_PU1_AMUX_THM3, 0)
VADC_CHAN_VOLT(LR_MUX7_PU1_AMUX_HW_ID, 0)
VADC_CHAN_VOLT(LR_MUX8_PU1_AMUX_THM4, 0)
VADC_CHAN_VOLT(LR_MUX9_PU1_AMUX_THM5, 0)
VADC_CHAN_VOLT(LR_MUX10_PU1_AMUX_USB_ID, 0)
VADC_CHAN_VOLT(LR_MUX3_BUF_PU1_XO_THERM, 0)
VADC_CHAN_VOLT(LR_MUX1_PU2_BAT_THERM, 0)
VADC_CHAN_VOLT(LR_MUX2_PU2_BAT_ID, 0)
VADC_CHAN_VOLT(LR_MUX3_PU2_XO_THERM, 0)
VADC_CHAN_VOLT(LR_MUX4_PU2_AMUX_THM1, 0)
VADC_CHAN_VOLT(LR_MUX5_PU2_AMUX_THM2, 0)
VADC_CHAN_VOLT(LR_MUX6_PU2_AMUX_THM3, 0)
VADC_CHAN_VOLT(LR_MUX7_PU2_AMUX_HW_ID, 0)
VADC_CHAN_VOLT(LR_MUX8_PU2_AMUX_THM4, 0)
VADC_CHAN_VOLT(LR_MUX9_PU2_AMUX_THM5, 0)
VADC_CHAN_VOLT(LR_MUX10_PU2_AMUX_USB_ID, 0)
VADC_CHAN_VOLT(LR_MUX3_BUF_PU2_XO_THERM, 0)
VADC_CHAN_VOLT(LR_MUX1_PU1_PU2_BAT_THERM, 0)
VADC_CHAN_VOLT(LR_MUX2_PU1_PU2_BAT_ID, 0)
VADC_CHAN_VOLT(LR_MUX3_PU1_PU2_XO_THERM, 0)
VADC_CHAN_VOLT(LR_MUX4_PU1_PU2_AMUX_THM1, 0)
VADC_CHAN_VOLT(LR_MUX5_PU1_PU2_AMUX_THM2, 0)
VADC_CHAN_VOLT(LR_MUX6_PU1_PU2_AMUX_THM3, 0)
VADC_CHAN_VOLT(LR_MUX7_PU1_PU2_AMUX_HW_ID, 0)
VADC_CHAN_VOLT(LR_MUX8_PU1_PU2_AMUX_THM4, 0)
VADC_CHAN_VOLT(LR_MUX9_PU1_PU2_AMUX_THM5, 0)
VADC_CHAN_VOLT(LR_MUX10_PU1_PU2_AMUX_USB_ID, 0)
VADC_CHAN_VOLT(LR_MUX3_BUF_PU1_PU2_XO_THERM, 0)
};
static int vadc_get_dt_channel_data(struct device *dev,
struct vadc_channel_prop *prop,
struct device_node *node)
{
const char *name = node->name;
u32 chan, value, varr[2];
int ret;
ret = of_property_read_u32(node, "reg", &chan);
if (ret) {
dev_err(dev, "invalid channel number %s\n", name);
return ret;
}
if (chan > VADC_CHAN_MAX || chan < VADC_CHAN_MIN) {
dev_err(dev, "%s invalid channel number %d\n", name, chan);
return -EINVAL;
}
/* the channel has DT description */
prop->channel = chan;
ret = of_property_read_u32(node, "qcom,decimation", &value);
if (!ret) {
ret = vadc_decimation_from_dt(value);
if (ret < 0) {
dev_err(dev, "%02x invalid decimation %d\n",
chan, value);
return ret;
}
prop->decimation = ret;
} else {
prop->decimation = VADC_DEF_DECIMATION;
}
ret = of_property_read_u32_array(node, "qcom,pre-scaling", varr, 2);
if (!ret) {
ret = vadc_prescaling_from_dt(varr[0], varr[1]);
if (ret < 0) {
dev_err(dev, "%02x invalid pre-scaling <%d %d>\n",
chan, varr[0], varr[1]);
return ret;
}
prop->prescale = ret;
} else {
prop->prescale = vadc_chans[prop->channel].prescale_index;
}
ret = of_property_read_u32(node, "qcom,hw-settle-time", &value);
if (!ret) {
ret = vadc_hw_settle_time_from_dt(value);
if (ret < 0) {
dev_err(dev, "%02x invalid hw-settle-time %d us\n",
chan, value);
return ret;
}
prop->hw_settle_time = ret;
} else {
prop->hw_settle_time = VADC_DEF_HW_SETTLE_TIME;
}
ret = of_property_read_u32(node, "qcom,avg-samples", &value);
if (!ret) {
ret = vadc_avg_samples_from_dt(value);
if (ret < 0) {
dev_err(dev, "%02x invalid avg-samples %d\n",
chan, value);
return ret;
}
prop->avg_samples = ret;
} else {
prop->avg_samples = VADC_DEF_AVG_SAMPLES;
}
if (of_property_read_bool(node, "qcom,ratiometric"))
prop->calibration = VADC_CALIB_RATIOMETRIC;
else
prop->calibration = VADC_CALIB_ABSOLUTE;
dev_dbg(dev, "%02x name %s\n", chan, name);
return 0;
}
static int vadc_get_dt_data(struct vadc_priv *vadc, struct device_node *node)
{
const struct vadc_channels *vadc_chan;
struct iio_chan_spec *iio_chan;
struct vadc_channel_prop prop;
struct device_node *child;
unsigned int index = 0;
int ret;
vadc->nchannels = of_get_available_child_count(node);
if (!vadc->nchannels)
return -EINVAL;
vadc->iio_chans = devm_kcalloc(vadc->dev, vadc->nchannels,
sizeof(*vadc->iio_chans), GFP_KERNEL);
if (!vadc->iio_chans)
return -ENOMEM;
vadc->chan_props = devm_kcalloc(vadc->dev, vadc->nchannels,
sizeof(*vadc->chan_props), GFP_KERNEL);
if (!vadc->chan_props)
return -ENOMEM;
iio_chan = vadc->iio_chans;
for_each_available_child_of_node(node, child) {
ret = vadc_get_dt_channel_data(vadc->dev, &prop, child);
if (ret)
return ret;
vadc->chan_props[index] = prop;
vadc_chan = &vadc_chans[prop.channel];
iio_chan->channel = prop.channel;
iio_chan->datasheet_name = vadc_chan->datasheet_name;
iio_chan->info_mask_separate = vadc_chan->info_mask;
iio_chan->type = vadc_chan->type;
iio_chan->indexed = 1;
iio_chan->address = index++;
iio_chan++;
}
/* These channels are mandatory, they are used as reference points */
if (!vadc_get_channel(vadc, VADC_REF_1250MV)) {
dev_err(vadc->dev, "Please define 1.25V channel\n");
return -ENODEV;
}
if (!vadc_get_channel(vadc, VADC_REF_625MV)) {
dev_err(vadc->dev, "Please define 0.625V channel\n");
return -ENODEV;
}
if (!vadc_get_channel(vadc, VADC_VDD_VADC)) {
dev_err(vadc->dev, "Please define VDD channel\n");
return -ENODEV;
}
if (!vadc_get_channel(vadc, VADC_GND_REF)) {
dev_err(vadc->dev, "Please define GND channel\n");
return -ENODEV;
}
return 0;
}
static irqreturn_t vadc_isr(int irq, void *dev_id)
{
struct vadc_priv *vadc = dev_id;
complete(&vadc->complete);
return IRQ_HANDLED;
}
static int vadc_check_revision(struct vadc_priv *vadc)
{
u8 val;
int ret;
ret = vadc_read(vadc, VADC_PERPH_TYPE, &val);
if (ret)
return ret;
if (val < VADC_PERPH_TYPE_ADC) {
dev_err(vadc->dev, "%d is not ADC\n", val);
return -ENODEV;
}
ret = vadc_read(vadc, VADC_PERPH_SUBTYPE, &val);
if (ret)
return ret;
if (val < VADC_PERPH_SUBTYPE_VADC) {
dev_err(vadc->dev, "%d is not VADC\n", val);
return -ENODEV;
}
ret = vadc_read(vadc, VADC_REVISION2, &val);
if (ret)
return ret;
if (val < VADC_REVISION2_SUPPORTED_VADC) {
dev_err(vadc->dev, "revision %d not supported\n", val);
return -ENODEV;
}
return 0;
}
static int vadc_probe(struct platform_device *pdev)
{
struct device_node *node = pdev->dev.of_node;
struct device *dev = &pdev->dev;
struct iio_dev *indio_dev;
struct vadc_priv *vadc;
struct regmap *regmap;
int ret, irq_eoc;
u32 reg;
regmap = dev_get_regmap(dev->parent, NULL);
if (!regmap)
return -ENODEV;
ret = of_property_read_u32(node, "reg", &reg);
if (ret < 0)
return ret;
indio_dev = devm_iio_device_alloc(dev, sizeof(*vadc));
if (!indio_dev)
return -ENOMEM;
vadc = iio_priv(indio_dev);
vadc->regmap = regmap;
vadc->dev = dev;
vadc->base = reg;
vadc->are_ref_measured = false;
init_completion(&vadc->complete);
mutex_init(&vadc->lock);
ret = vadc_check_revision(vadc);
if (ret)
return ret;
ret = vadc_get_dt_data(vadc, node);
if (ret)
return ret;
irq_eoc = platform_get_irq(pdev, 0);
if (irq_eoc < 0) {
if (irq_eoc == -EPROBE_DEFER || irq_eoc == -EINVAL)
return irq_eoc;
vadc->poll_eoc = true;
} else {
ret = devm_request_irq(dev, irq_eoc, vadc_isr, 0,
"spmi-vadc", vadc);
if (ret)
return ret;
}
ret = vadc_reset(vadc);
if (ret) {
dev_err(dev, "reset failed\n");
return ret;
}
ret = vadc_measure_ref_points(vadc);
if (ret)
return ret;
indio_dev->dev.parent = dev;
indio_dev->dev.of_node = node;
indio_dev->name = pdev->name;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &vadc_info;
indio_dev->channels = vadc->iio_chans;
indio_dev->num_channels = vadc->nchannels;
return devm_iio_device_register(dev, indio_dev);
}
static const struct of_device_id vadc_match_table[] = {
{ .compatible = "qcom,spmi-vadc" },
{ }
};
MODULE_DEVICE_TABLE(of, vadc_match_table);
static struct platform_driver vadc_driver = {
.driver = {
.name = "qcom-spmi-vadc",
.of_match_table = vadc_match_table,
},
.probe = vadc_probe,
};
module_platform_driver(vadc_driver);
MODULE_ALIAS("platform:qcom-spmi-vadc");
MODULE_DESCRIPTION("Qualcomm SPMI PMIC voltage ADC driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>");
MODULE_AUTHOR("Ivan T. Ivanov <iivanov@mm-sol.com>");
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