// SPDX-License-Identifier: GPL-2.0
#include <linux/bits.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/ktime.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <asm/unaligned.h>
#define MT6360_REG_PMUCHGCTRL3 0x313
#define MT6360_REG_PMUADCCFG 0x356
#define MT6360_REG_PMUADCIDLET 0x358
#define MT6360_REG_PMUADCRPT1 0x35A
/* PMUCHGCTRL3 0x313 */
#define MT6360_AICR_MASK GENMASK(7, 2)
#define MT6360_AICR_SHFT 2
#define MT6360_AICR_400MA 0x6
/* PMUADCCFG 0x356 */
#define MT6360_ADCEN_MASK BIT(15)
/* PMUADCRPT1 0x35A */
#define MT6360_PREFERCH_MASK GENMASK(7, 4)
#define MT6360_PREFERCH_SHFT 4
#define MT6360_RPTCH_MASK GENMASK(3, 0)
#define MT6360_NO_PREFER 15
/* Time in ms */
#define ADC_WAIT_TIME_MS 25
#define ADC_CONV_TIMEOUT_MS 100
#define ADC_LOOP_TIME_US 2000
enum {
MT6360_CHAN_USBID = 0,
MT6360_CHAN_VBUSDIV5,
MT6360_CHAN_VBUSDIV2,
MT6360_CHAN_VSYS,
MT6360_CHAN_VBAT,
MT6360_CHAN_IBUS,
MT6360_CHAN_IBAT,
MT6360_CHAN_CHG_VDDP,
MT6360_CHAN_TEMP_JC,
MT6360_CHAN_VREF_TS,
MT6360_CHAN_TS,
MT6360_CHAN_MAX
};
struct mt6360_adc_data {
struct device *dev;
struct regmap *regmap;
/* Due to only one set of ADC control, this lock is used to prevent the race condition */
struct mutex adc_lock;
ktime_t last_off_timestamps[MT6360_CHAN_MAX];
};
static int mt6360_adc_read_channel(struct mt6360_adc_data *mad, int channel, int *val)
{
__be16 adc_enable;
u8 rpt[3];
ktime_t predict_end_t, timeout;
unsigned int pre_wait_time;
int ret;
mutex_lock(&mad->adc_lock);
/* Select the preferred ADC channel */
ret = regmap_update_bits(mad->regmap, MT6360_REG_PMUADCRPT1, MT6360_PREFERCH_MASK,
channel << MT6360_PREFERCH_SHFT);
if (ret)
goto out_adc_lock;
adc_enable = cpu_to_be16(MT6360_ADCEN_MASK | BIT(channel));
ret = regmap_raw_write(mad->regmap, MT6360_REG_PMUADCCFG, &adc_enable, sizeof(adc_enable));
if (ret)
goto out_adc_lock;
predict_end_t = ktime_add_ms(mad->last_off_timestamps[channel], 2 * ADC_WAIT_TIME_MS);
if (ktime_after(ktime_get(), predict_end_t))
pre_wait_time = ADC_WAIT_TIME_MS;
else
pre_wait_time = 3 * ADC_WAIT_TIME_MS;
if (msleep_interruptible(pre_wait_time)) {
ret = -ERESTARTSYS;
goto out_adc_conv;
}
timeout = ktime_add_ms(ktime_get(), ADC_CONV_TIMEOUT_MS);
while (true) {
ret = regmap_raw_read(mad->regmap, MT6360_REG_PMUADCRPT1, rpt, sizeof(rpt));
if (ret)
goto out_adc_conv;
/*
* There are two functions, ZCV and TypeC OTP, running ADC VBAT and TS in
* background, and ADC samples are taken on a fixed frequency no matter read the
* previous one or not.
* To avoid conflict, We set minimum time threshold after enable ADC and
* check report channel is the same.
* The worst case is run the same ADC twice and background function is also running,
* ADC conversion sequence is desire channel before start ADC, background ADC,
* desire channel after start ADC.
* So the minimum correct data is three times of typical conversion time.
*/
if ((rpt[0] & MT6360_RPTCH_MASK) == channel)
break;
if (ktime_compare(ktime_get(), timeout) > 0) {
ret = -ETIMEDOUT;
goto out_adc_conv;
}
usleep_range(ADC_LOOP_TIME_US / 2, ADC_LOOP_TIME_US);
}
*val = rpt[1] << 8 | rpt[2];
ret = IIO_VAL_INT;
out_adc_conv:
/* Only keep ADC enable */
adc_enable = cpu_to_be16(MT6360_ADCEN_MASK);
regmap_raw_write(mad->regmap, MT6360_REG_PMUADCCFG, &adc_enable, sizeof(adc_enable));
mad->last_off_timestamps[channel] = ktime_get();
/* Config prefer channel to NO_PREFER */
regmap_update_bits(mad->regmap, MT6360_REG_PMUADCRPT1, MT6360_PREFERCH_MASK,
MT6360_NO_PREFER << MT6360_PREFERCH_SHFT);
out_adc_lock:
mutex_unlock(&mad->adc_lock);
return ret;
}
static int mt6360_adc_read_scale(struct mt6360_adc_data *mad, int channel, int *val, int *val2)
{
unsigned int regval;
int ret;
switch (channel) {
case MT6360_CHAN_USBID:
case MT6360_CHAN_VSYS:
case MT6360_CHAN_VBAT:
case MT6360_CHAN_CHG_VDDP:
case MT6360_CHAN_VREF_TS:
case MT6360_CHAN_TS:
*val = 1250;
return IIO_VAL_INT;
case MT6360_CHAN_VBUSDIV5:
*val = 6250;
return IIO_VAL_INT;
case MT6360_CHAN_VBUSDIV2:
case MT6360_CHAN_IBUS:
case MT6360_CHAN_IBAT:
*val = 2500;
if (channel == MT6360_CHAN_IBUS) {
/* IBUS will be affected by input current limit for the different Ron */
/* Check whether the config is <400mA or not */
ret = regmap_read(mad->regmap, MT6360_REG_PMUCHGCTRL3, ®val);
if (ret)
return ret;
regval = (regval & MT6360_AICR_MASK) >> MT6360_AICR_SHFT;
if (regval < MT6360_AICR_400MA)
*val = 1900;
}
return IIO_VAL_INT;
case MT6360_CHAN_TEMP_JC:
*val = 105;
*val2 = 100;
return IIO_VAL_FRACTIONAL;
}
return -EINVAL;
}
static int mt6360_adc_read_offset(struct mt6360_adc_data *mad, int channel, int *val)
{
*val = (channel == MT6360_CHAN_TEMP_JC) ? -80 : 0;
return IIO_VAL_INT;
}
static int mt6360_adc_read_raw(struct iio_dev *iio_dev, const struct iio_chan_spec *chan,
int *val, int *val2, long mask)
{
struct mt6360_adc_data *mad = iio_priv(iio_dev);
switch (mask) {
case IIO_CHAN_INFO_RAW:
return mt6360_adc_read_channel(mad, chan->channel, val);
case IIO_CHAN_INFO_SCALE:
return mt6360_adc_read_scale(mad, chan->channel, val, val2);
case IIO_CHAN_INFO_OFFSET:
return mt6360_adc_read_offset(mad, chan->channel, val);
}
return -EINVAL;
}
static const char *mt6360_channel_labels[MT6360_CHAN_MAX] = {
"usbid", "vbusdiv5", "vbusdiv2", "vsys", "vbat", "ibus", "ibat", "chg_vddp",
"temp_jc", "vref_ts", "ts",
};
static int mt6360_adc_read_label(struct iio_dev *iio_dev, const struct iio_chan_spec *chan,
char *label)
{
return snprintf(label, PAGE_SIZE, "%s\n", mt6360_channel_labels[chan->channel]);
}
static const struct iio_info mt6360_adc_iio_info = {
.read_raw = mt6360_adc_read_raw,
.read_label = mt6360_adc_read_label,
};
#define MT6360_ADC_CHAN(_idx, _type) { \
.type = _type, \
.channel = MT6360_CHAN_##_idx, \
.scan_index = MT6360_CHAN_##_idx, \
.datasheet_name = #_idx, \
.scan_type = { \
.sign = 'u', \
.realbits = 16, \
.storagebits = 16, \
.endianness = IIO_CPU, \
}, \
.indexed = 1, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_OFFSET), \
}
static const struct iio_chan_spec mt6360_adc_channels[] = {
MT6360_ADC_CHAN(USBID, IIO_VOLTAGE),
MT6360_ADC_CHAN(VBUSDIV5, IIO_VOLTAGE),
MT6360_ADC_CHAN(VBUSDIV2, IIO_VOLTAGE),
MT6360_ADC_CHAN(VSYS, IIO_VOLTAGE),
MT6360_ADC_CHAN(VBAT, IIO_VOLTAGE),
MT6360_ADC_CHAN(IBUS, IIO_CURRENT),
MT6360_ADC_CHAN(IBAT, IIO_CURRENT),
MT6360_ADC_CHAN(CHG_VDDP, IIO_VOLTAGE),
MT6360_ADC_CHAN(TEMP_JC, IIO_TEMP),
MT6360_ADC_CHAN(VREF_TS, IIO_VOLTAGE),
MT6360_ADC_CHAN(TS, IIO_VOLTAGE),
IIO_CHAN_SOFT_TIMESTAMP(MT6360_CHAN_MAX),
};
static irqreturn_t mt6360_adc_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct mt6360_adc_data *mad = iio_priv(indio_dev);
struct {
u16 values[MT6360_CHAN_MAX];
int64_t timestamp;
} data __aligned(8);
int i = 0, bit, val, ret;
memset(&data, 0, sizeof(data));
for_each_set_bit(bit, indio_dev->active_scan_mask, indio_dev->masklength) {
ret = mt6360_adc_read_channel(mad, bit, &val);
if (ret < 0) {
dev_warn(&indio_dev->dev, "Failed to get channel %d conversion val\n", bit);
goto out;
}
data.values[i++] = val;
}
iio_push_to_buffers_with_timestamp(indio_dev, &data, iio_get_time_ns(indio_dev));
out:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static inline int mt6360_adc_reset(struct mt6360_adc_data *info)
{
__be16 adc_enable;
ktime_t all_off_time;
int i, ret;
/* Clear ADC idle wait time to 0 */
ret = regmap_write(info->regmap, MT6360_REG_PMUADCIDLET, 0);
if (ret)
return ret;
/* Only keep ADC enable, but keep all channels off */
adc_enable = cpu_to_be16(MT6360_ADCEN_MASK);
ret = regmap_raw_write(info->regmap, MT6360_REG_PMUADCCFG, &adc_enable, sizeof(adc_enable));
if (ret)
return ret;
/* Reset all channel off time to the current one */
all_off_time = ktime_get();
for (i = 0; i < MT6360_CHAN_MAX; i++)
info->last_off_timestamps[i] = all_off_time;
return 0;
}
static int mt6360_adc_probe(struct platform_device *pdev)
{
struct mt6360_adc_data *mad;
struct regmap *regmap;
struct iio_dev *indio_dev;
int ret;
regmap = dev_get_regmap(pdev->dev.parent, NULL);
if (!regmap) {
dev_err(&pdev->dev, "Failed to get parent regmap\n");
return -ENODEV;
}
indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*mad));
if (!indio_dev)
return -ENOMEM;
mad = iio_priv(indio_dev);
mad->dev = &pdev->dev;
mad->regmap = regmap;
mutex_init(&mad->adc_lock);
ret = mt6360_adc_reset(mad);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to reset adc\n");
return ret;
}
indio_dev->name = dev_name(&pdev->dev);
indio_dev->info = &mt6360_adc_iio_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = mt6360_adc_channels;
indio_dev->num_channels = ARRAY_SIZE(mt6360_adc_channels);
ret = devm_iio_triggered_buffer_setup(&pdev->dev, indio_dev, NULL,
mt6360_adc_trigger_handler, NULL);
if (ret) {
dev_err(&pdev->dev, "Failed to allocate iio trigger buffer\n");
return ret;
}
return devm_iio_device_register(&pdev->dev, indio_dev);
}
static const struct of_device_id mt6360_adc_of_id[] = {
{ .compatible = "mediatek,mt6360-adc", },
{}
};
MODULE_DEVICE_TABLE(of, mt6360_adc_of_id);
static struct platform_driver mt6360_adc_driver = {
.driver = {
.name = "mt6360-adc",
.of_match_table = mt6360_adc_of_id,
},
.probe = mt6360_adc_probe,
};
module_platform_driver(mt6360_adc_driver);
MODULE_AUTHOR("Gene Chen <gene_chen@richtek.com>");
MODULE_DESCRIPTION("MT6360 ADC Driver");
MODULE_LICENSE("GPL v2");
