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berlin2-adc.c
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berlin2-adc.c
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/*
* Marvell Berlin2 ADC driver
*
* Copyright (C) 2015 Marvell Technology Group Ltd.
*
* Antoine Tenart <antoine.tenart@free-electrons.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/iio/iio.h>
#include <linux/iio/driver.h>
#include <linux/iio/machine.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/sched.h>
#include <linux/wait.h>
#define BERLIN2_SM_CTRL 0x14
#define BERLIN2_SM_CTRL_SM_SOC_INT BIT(1)
#define BERLIN2_SM_CTRL_SOC_SM_INT BIT(2)
#define BERLIN2_SM_CTRL_ADC_SEL(x) ((x) << 5) /* 0-15 */
#define BERLIN2_SM_CTRL_ADC_SEL_MASK GENMASK(8, 5)
#define BERLIN2_SM_CTRL_ADC_POWER BIT(9)
#define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV2 (0x0 << 10)
#define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV3 (0x1 << 10)
#define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV4 (0x2 << 10)
#define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV8 (0x3 << 10)
#define BERLIN2_SM_CTRL_ADC_CLKSEL_MASK GENMASK(11, 10)
#define BERLIN2_SM_CTRL_ADC_START BIT(12)
#define BERLIN2_SM_CTRL_ADC_RESET BIT(13)
#define BERLIN2_SM_CTRL_ADC_BANDGAP_RDY BIT(14)
#define BERLIN2_SM_CTRL_ADC_CONT_SINGLE (0x0 << 15)
#define BERLIN2_SM_CTRL_ADC_CONT_CONTINUOUS (0x1 << 15)
#define BERLIN2_SM_CTRL_ADC_BUFFER_EN BIT(16)
#define BERLIN2_SM_CTRL_ADC_VREF_EXT (0x0 << 17)
#define BERLIN2_SM_CTRL_ADC_VREF_INT (0x1 << 17)
#define BERLIN2_SM_CTRL_ADC_ROTATE BIT(19)
#define BERLIN2_SM_CTRL_TSEN_EN BIT(20)
#define BERLIN2_SM_CTRL_TSEN_CLK_SEL_125 (0x0 << 21) /* 1.25 MHz */
#define BERLIN2_SM_CTRL_TSEN_CLK_SEL_250 (0x1 << 21) /* 2.5 MHz */
#define BERLIN2_SM_CTRL_TSEN_MODE_0_125 (0x0 << 22) /* 0-125 C */
#define BERLIN2_SM_CTRL_TSEN_MODE_10_50 (0x1 << 22) /* 10-50 C */
#define BERLIN2_SM_CTRL_TSEN_RESET BIT(29)
#define BERLIN2_SM_ADC_DATA 0x20
#define BERLIN2_SM_ADC_MASK GENMASK(9, 0)
#define BERLIN2_SM_ADC_STATUS 0x1c
#define BERLIN2_SM_ADC_STATUS_DATA_RDY(x) BIT(x) /* 0-15 */
#define BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK GENMASK(15, 0)
#define BERLIN2_SM_ADC_STATUS_INT_EN(x) (BIT(x) << 16) /* 0-15 */
#define BERLIN2_SM_ADC_STATUS_INT_EN_MASK GENMASK(31, 16)
#define BERLIN2_SM_TSEN_STATUS 0x24
#define BERLIN2_SM_TSEN_STATUS_DATA_RDY BIT(0)
#define BERLIN2_SM_TSEN_STATUS_INT_EN BIT(1)
#define BERLIN2_SM_TSEN_DATA 0x28
#define BERLIN2_SM_TSEN_MASK GENMASK(9, 0)
#define BERLIN2_SM_TSEN_CTRL 0x74
#define BERLIN2_SM_TSEN_CTRL_START BIT(8)
#define BERLIN2_SM_TSEN_CTRL_SETTLING_4 (0x0 << 21) /* 4 us */
#define BERLIN2_SM_TSEN_CTRL_SETTLING_12 (0x1 << 21) /* 12 us */
#define BERLIN2_SM_TSEN_CTRL_SETTLING_MASK BIT(21)
#define BERLIN2_SM_TSEN_CTRL_TRIM(x) ((x) << 22)
#define BERLIN2_SM_TSEN_CTRL_TRIM_MASK GENMASK(25, 22)
struct berlin2_adc_priv {
struct regmap *regmap;
struct mutex lock;
wait_queue_head_t wq;
bool data_available;
int data;
};
#define BERLIN2_ADC_CHANNEL(n, t) \
{ \
.channel = n, \
.datasheet_name = "channel"#n, \
.type = t, \
.indexed = 1, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
}
static const struct iio_chan_spec berlin2_adc_channels[] = {
BERLIN2_ADC_CHANNEL(0, IIO_VOLTAGE), /* external input */
BERLIN2_ADC_CHANNEL(1, IIO_VOLTAGE), /* external input */
BERLIN2_ADC_CHANNEL(2, IIO_VOLTAGE), /* external input */
BERLIN2_ADC_CHANNEL(3, IIO_VOLTAGE), /* external input */
BERLIN2_ADC_CHANNEL(4, IIO_VOLTAGE), /* reserved */
BERLIN2_ADC_CHANNEL(5, IIO_VOLTAGE), /* reserved */
{ /* temperature sensor */
.channel = 6,
.datasheet_name = "channel6",
.type = IIO_TEMP,
.indexed = 0,
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
},
BERLIN2_ADC_CHANNEL(7, IIO_VOLTAGE), /* reserved */
IIO_CHAN_SOFT_TIMESTAMP(8), /* timestamp */
};
static int berlin2_adc_read(struct iio_dev *indio_dev, int channel)
{
struct berlin2_adc_priv *priv = iio_priv(indio_dev);
int data, ret;
mutex_lock(&priv->lock);
/* Enable the interrupts */
regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS,
BERLIN2_SM_ADC_STATUS_INT_EN(channel));
/* Configure the ADC */
regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
BERLIN2_SM_CTRL_ADC_RESET |
BERLIN2_SM_CTRL_ADC_SEL_MASK |
BERLIN2_SM_CTRL_ADC_START,
BERLIN2_SM_CTRL_ADC_SEL(channel) |
BERLIN2_SM_CTRL_ADC_START);
ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
msecs_to_jiffies(1000));
/* Disable the interrupts */
regmap_update_bits(priv->regmap, BERLIN2_SM_ADC_STATUS,
BERLIN2_SM_ADC_STATUS_INT_EN(channel), 0);
if (ret == 0)
ret = -ETIMEDOUT;
if (ret < 0) {
mutex_unlock(&priv->lock);
return ret;
}
regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
BERLIN2_SM_CTRL_ADC_START, 0);
data = priv->data;
priv->data_available = false;
mutex_unlock(&priv->lock);
return data;
}
static int berlin2_adc_tsen_read(struct iio_dev *indio_dev)
{
struct berlin2_adc_priv *priv = iio_priv(indio_dev);
int data, ret;
mutex_lock(&priv->lock);
/* Enable interrupts */
regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS,
BERLIN2_SM_TSEN_STATUS_INT_EN);
/* Configure the ADC */
regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
BERLIN2_SM_CTRL_TSEN_RESET |
BERLIN2_SM_CTRL_ADC_ROTATE,
BERLIN2_SM_CTRL_ADC_ROTATE);
/* Configure the temperature sensor */
regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
BERLIN2_SM_TSEN_CTRL_TRIM_MASK |
BERLIN2_SM_TSEN_CTRL_SETTLING_MASK |
BERLIN2_SM_TSEN_CTRL_START,
BERLIN2_SM_TSEN_CTRL_TRIM(3) |
BERLIN2_SM_TSEN_CTRL_SETTLING_12 |
BERLIN2_SM_TSEN_CTRL_START);
ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
msecs_to_jiffies(1000));
/* Disable interrupts */
regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_STATUS,
BERLIN2_SM_TSEN_STATUS_INT_EN, 0);
if (ret == 0)
ret = -ETIMEDOUT;
if (ret < 0) {
mutex_unlock(&priv->lock);
return ret;
}
regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
BERLIN2_SM_TSEN_CTRL_START, 0);
data = priv->data;
priv->data_available = false;
mutex_unlock(&priv->lock);
return data;
}
static int berlin2_adc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val,
int *val2, long mask)
{
int temp;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (chan->type != IIO_VOLTAGE)
return -EINVAL;
*val = berlin2_adc_read(indio_dev, chan->channel);
if (*val < 0)
return *val;
return IIO_VAL_INT;
case IIO_CHAN_INFO_PROCESSED:
if (chan->type != IIO_TEMP)
return -EINVAL;
temp = berlin2_adc_tsen_read(indio_dev);
if (temp < 0)
return temp;
if (temp > 2047)
temp -= 4096;
/* Convert to milli Celsius */
*val = ((temp * 100000) / 264 - 270000);
return IIO_VAL_INT;
default:
break;
}
return -EINVAL;
}
static irqreturn_t berlin2_adc_irq(int irq, void *private)
{
struct berlin2_adc_priv *priv = iio_priv(private);
unsigned val;
regmap_read(priv->regmap, BERLIN2_SM_ADC_STATUS, &val);
if (val & BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK) {
regmap_read(priv->regmap, BERLIN2_SM_ADC_DATA, &priv->data);
priv->data &= BERLIN2_SM_ADC_MASK;
val &= ~BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK;
regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS, val);
priv->data_available = true;
wake_up_interruptible(&priv->wq);
}
return IRQ_HANDLED;
}
static irqreturn_t berlin2_adc_tsen_irq(int irq, void *private)
{
struct berlin2_adc_priv *priv = iio_priv(private);
unsigned val;
regmap_read(priv->regmap, BERLIN2_SM_TSEN_STATUS, &val);
if (val & BERLIN2_SM_TSEN_STATUS_DATA_RDY) {
regmap_read(priv->regmap, BERLIN2_SM_TSEN_DATA, &priv->data);
priv->data &= BERLIN2_SM_TSEN_MASK;
val &= ~BERLIN2_SM_TSEN_STATUS_DATA_RDY;
regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS, val);
priv->data_available = true;
wake_up_interruptible(&priv->wq);
}
return IRQ_HANDLED;
}
static const struct iio_info berlin2_adc_info = {
.read_raw = berlin2_adc_read_raw,
};
static void berlin2_adc_powerdown(void *regmap)
{
regmap_update_bits(regmap, BERLIN2_SM_CTRL,
BERLIN2_SM_CTRL_ADC_POWER, 0);
}
static int berlin2_adc_probe(struct platform_device *pdev)
{
struct iio_dev *indio_dev;
struct berlin2_adc_priv *priv;
struct device_node *parent_np = of_get_parent(pdev->dev.of_node);
int irq, tsen_irq;
int ret;
indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
if (!indio_dev) {
of_node_put(parent_np);
return -ENOMEM;
}
priv = iio_priv(indio_dev);
priv->regmap = syscon_node_to_regmap(parent_np);
of_node_put(parent_np);
if (IS_ERR(priv->regmap))
return PTR_ERR(priv->regmap);
irq = platform_get_irq_byname(pdev, "adc");
if (irq < 0)
return irq;
tsen_irq = platform_get_irq_byname(pdev, "tsen");
if (tsen_irq < 0)
return tsen_irq;
ret = devm_request_irq(&pdev->dev, irq, berlin2_adc_irq, 0,
pdev->dev.driver->name, indio_dev);
if (ret)
return ret;
ret = devm_request_irq(&pdev->dev, tsen_irq, berlin2_adc_tsen_irq,
0, pdev->dev.driver->name, indio_dev);
if (ret)
return ret;
init_waitqueue_head(&priv->wq);
mutex_init(&priv->lock);
indio_dev->name = dev_name(&pdev->dev);
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &berlin2_adc_info;
indio_dev->channels = berlin2_adc_channels;
indio_dev->num_channels = ARRAY_SIZE(berlin2_adc_channels);
/* Power up the ADC */
regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
BERLIN2_SM_CTRL_ADC_POWER,
BERLIN2_SM_CTRL_ADC_POWER);
ret = devm_add_action_or_reset(&pdev->dev, berlin2_adc_powerdown,
priv->regmap);
if (ret)
return ret;
return devm_iio_device_register(&pdev->dev, indio_dev);
}
static const struct of_device_id berlin2_adc_match[] = {
{ .compatible = "marvell,berlin2-adc", },
{ },
};
MODULE_DEVICE_TABLE(of, berlin2_adc_match);
static struct platform_driver berlin2_adc_driver = {
.driver = {
.name = "berlin2-adc",
.of_match_table = berlin2_adc_match,
},
.probe = berlin2_adc_probe,
};
module_platform_driver(berlin2_adc_driver);
MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
MODULE_DESCRIPTION("Marvell Berlin2 ADC driver");
MODULE_LICENSE("GPL v2");