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/* ADC driver for sunxi platforms' (A10, A13 and A31) GPADC
*
* Copyright (c) 2016 Quentin Schulz <quentin.schulz@free-electrons.com>
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License version 2 as published by the
* Free Software Foundation.
*
* The Allwinner SoCs all have an ADC that can also act as a touchscreen
* controller and a thermal sensor.
* The thermal sensor works only when the ADC acts as a touchscreen controller
* and is configured to throw an interrupt every fixed periods of time (let say
* every X seconds).
* One would be tempted to disable the IP on the hardware side rather than
* disabling interrupts to save some power but that resets the internal clock of
* the IP, resulting in having to wait X seconds every time we want to read the
* value of the thermal sensor.
* This is also the reason of using autosuspend in pm_runtime. If there was no
* autosuspend, the thermal sensor would need X seconds after every
* pm_runtime_get_sync to get a value from the ADC. The autosuspend allows the
* thermal sensor to be requested again in a certain time span before it gets
* shutdown for not being used.
*/
#include <linux/completion.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/thermal.h>
#include <linux/delay.h>
#include <linux/iio/iio.h>
#include <linux/iio/driver.h>
#include <linux/iio/machine.h>
#include <linux/mfd/sun4i-gpadc.h>
static unsigned int sun4i_gpadc_chan_select(unsigned int chan)
{
return SUN4I_GPADC_CTRL1_ADC_CHAN_SELECT(chan);
}
static unsigned int sun6i_gpadc_chan_select(unsigned int chan)
{
return SUN6I_GPADC_CTRL1_ADC_CHAN_SELECT(chan);
}
struct gpadc_data {
int temp_offset;
int temp_scale;
unsigned int tp_mode_en;
unsigned int tp_adc_select;
unsigned int (*adc_chan_select)(unsigned int chan);
unsigned int adc_chan_mask;
};
static const struct gpadc_data sun4i_gpadc_data = {
.temp_offset = -1932,
.temp_scale = 133,
.tp_mode_en = SUN4I_GPADC_CTRL1_TP_MODE_EN,
.tp_adc_select = SUN4I_GPADC_CTRL1_TP_ADC_SELECT,
.adc_chan_select = &sun4i_gpadc_chan_select,
.adc_chan_mask = SUN4I_GPADC_CTRL1_ADC_CHAN_MASK,
};
static const struct gpadc_data sun5i_gpadc_data = {
.temp_offset = -1447,
.temp_scale = 100,
.tp_mode_en = SUN4I_GPADC_CTRL1_TP_MODE_EN,
.tp_adc_select = SUN4I_GPADC_CTRL1_TP_ADC_SELECT,
.adc_chan_select = &sun4i_gpadc_chan_select,
.adc_chan_mask = SUN4I_GPADC_CTRL1_ADC_CHAN_MASK,
};
static const struct gpadc_data sun6i_gpadc_data = {
.temp_offset = -1623,
.temp_scale = 167,
.tp_mode_en = SUN6I_GPADC_CTRL1_TP_MODE_EN,
.tp_adc_select = SUN6I_GPADC_CTRL1_TP_ADC_SELECT,
.adc_chan_select = &sun6i_gpadc_chan_select,
.adc_chan_mask = SUN6I_GPADC_CTRL1_ADC_CHAN_MASK,
};
static const struct gpadc_data sun8i_a33_gpadc_data = {
.temp_offset = -1662,
.temp_scale = 162,
.tp_mode_en = SUN8I_GPADC_CTRL1_CHOP_TEMP_EN,
};
struct sun4i_gpadc_iio {
struct iio_dev *indio_dev;
struct completion completion;
int temp_data;
u32 adc_data;
struct regmap *regmap;
unsigned int fifo_data_irq;
atomic_t ignore_fifo_data_irq;
unsigned int temp_data_irq;
atomic_t ignore_temp_data_irq;
const struct gpadc_data *data;
bool no_irq;
/* prevents concurrent reads of temperature and ADC */
struct mutex mutex;
struct thermal_zone_device *tzd;
struct device *sensor_device;
};
#define SUN4I_GPADC_ADC_CHANNEL(_channel, _name) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = _channel, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.datasheet_name = _name, \
}
static struct iio_map sun4i_gpadc_hwmon_maps[] = {
{
.adc_channel_label = "temp_adc",
.consumer_dev_name = "iio_hwmon.0",
},
{ /* sentinel */ },
};
static const struct iio_chan_spec sun4i_gpadc_channels[] = {
SUN4I_GPADC_ADC_CHANNEL(0, "adc_chan0"),
SUN4I_GPADC_ADC_CHANNEL(1, "adc_chan1"),
SUN4I_GPADC_ADC_CHANNEL(2, "adc_chan2"),
SUN4I_GPADC_ADC_CHANNEL(3, "adc_chan3"),
{
.type = IIO_TEMP,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OFFSET),
.datasheet_name = "temp_adc",
},
};
static const struct iio_chan_spec sun4i_gpadc_channels_no_temp[] = {
SUN4I_GPADC_ADC_CHANNEL(0, "adc_chan0"),
SUN4I_GPADC_ADC_CHANNEL(1, "adc_chan1"),
SUN4I_GPADC_ADC_CHANNEL(2, "adc_chan2"),
SUN4I_GPADC_ADC_CHANNEL(3, "adc_chan3"),
};
static const struct iio_chan_spec sun8i_a33_gpadc_channels[] = {
{
.type = IIO_TEMP,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OFFSET),
.datasheet_name = "temp_adc",
},
};
static const struct regmap_config sun4i_gpadc_regmap_config = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = 4,
.fast_io = true,
};
static int sun4i_prepare_for_irq(struct iio_dev *indio_dev, int channel,
unsigned int irq)
{
struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
int ret;
u32 reg;
pm_runtime_get_sync(indio_dev->dev.parent);
reinit_completion(&info->completion);
ret = regmap_write(info->regmap, SUN4I_GPADC_INT_FIFOC,
SUN4I_GPADC_INT_FIFOC_TP_FIFO_TRIG_LEVEL(1) |
SUN4I_GPADC_INT_FIFOC_TP_FIFO_FLUSH);
if (ret)
return ret;
ret = regmap_read(info->regmap, SUN4I_GPADC_CTRL1, ®);
if (ret)
return ret;
if (irq == info->fifo_data_irq) {
ret = regmap_write(info->regmap, SUN4I_GPADC_CTRL1,
info->data->tp_mode_en |
info->data->tp_adc_select |
info->data->adc_chan_select(channel));
/*
* When the IP changes channel, it needs a bit of time to get
* correct values.
*/
if ((reg & info->data->adc_chan_mask) !=
info->data->adc_chan_select(channel))
mdelay(10);
} else {
/*
* The temperature sensor returns valid data only when the ADC
* operates in touchscreen mode.
*/
ret = regmap_write(info->regmap, SUN4I_GPADC_CTRL1,
info->data->tp_mode_en);
}
if (ret)
return ret;
/*
* When the IP changes mode between ADC or touchscreen, it
* needs a bit of time to get correct values.
*/
if ((reg & info->data->tp_adc_select) != info->data->tp_adc_select)
mdelay(100);
return 0;
}
static int sun4i_gpadc_read
|