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iio: adc: mxs-lradc: Add support for ADC driver 

Add support for sixteen-channel 12-bit resolution ADC and its functions,
which include general-purpose ADC readings, battery voltage measurement,
and die temperature measurement.

Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
Reviewed-by: Jonathan Cameron <jic23@kernel.org>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
This commit is contained in:
Ksenija Stanojevic 2017-03-16 13:27:10 +01:00 committed by Lee Jones
parent ead25133e9
commit 6dd112b9f8
3 changed files with 857 additions and 0 deletions
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13
drivers/iio/adc/Kconfig
View File

@ -229,6 +229,19 @@ config EXYNOS_ADC
To compile this driver as a module, choose M here: the module will be
called exynos_adc.
config MXS_LRADC_ADC
tristate "Freescale i.MX23/i.MX28 LRADC ADC"
depends on MFD_MXS_LRADC
select IIO_BUFFER
select IIO_TRIGGERED_BUFFER
help
Say yes here to build support for the ADC functions of the
i.MX23/i.MX28 LRADC. This includes general-purpose ADC readings,
battery voltage measurement, and die temperature measurement.
This driver can also be built as a module. If so, the module will be
called mxs-lradc-adc.
config FSL_MX25_ADC
tristate "Freescale MX25 ADC driver"
depends on MFD_MX25_TSADC

1
drivers/iio/adc/Makefile
View File

@ -39,6 +39,7 @@ obj-$(CONFIG_MCP3422) += mcp3422.o
obj-$(CONFIG_MEDIATEK_MT6577_AUXADC) += mt6577_auxadc.o
obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o
obj-$(CONFIG_MESON_SARADC) += meson_saradc.o
obj-$(CONFIG_MXS_LRADC_ADC) += mxs-lradc-adc.o
obj-$(CONFIG_MXS_LRADC) += mxs-lradc.o
obj-$(CONFIG_NAU7802) += nau7802.o
obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o

843
drivers/iio/adc/mxs-lradc-adc.c Normal file
View File

@ -0,0 +1,843 @@
/*
* Freescale MXS LRADC ADC driver
*
* Copyright (c) 2012 DENX Software Engineering, GmbH.
* Copyright (c) 2017 Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
*
* Authors:
* Marek Vasut <marex@denx.de>
* Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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/completion.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/mfd/core.h>
#include <linux/mfd/mxs-lradc.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/sysfs.h>
/*
* Make this runtime configurable if necessary. Currently, if the buffered mode
* is enabled, the LRADC takes LRADC_DELAY_TIMER_LOOP samples of data before
* triggering IRQ. The sampling happens every (LRADC_DELAY_TIMER_PER / 2000)
* seconds. The result is that the samples arrive every 500mS.
*/
#define LRADC_DELAY_TIMER_PER 200
#define LRADC_DELAY_TIMER_LOOP 5
#define VREF_MV_BASE 1850
const char *mx23_lradc_adc_irq_names[] = {
"mxs-lradc-channel0",
"mxs-lradc-channel1",
"mxs-lradc-channel2",
"mxs-lradc-channel3",
"mxs-lradc-channel4",
"mxs-lradc-channel5",
};
const char *mx28_lradc_adc_irq_names[] = {
"mxs-lradc-thresh0",
"mxs-lradc-thresh1",
"mxs-lradc-channel0",
"mxs-lradc-channel1",
"mxs-lradc-channel2",
"mxs-lradc-channel3",
"mxs-lradc-channel4",
"mxs-lradc-channel5",
"mxs-lradc-button0",
"mxs-lradc-button1",
};
static const u32 mxs_lradc_adc_vref_mv[][LRADC_MAX_TOTAL_CHANS] = {
[IMX23_LRADC] = {
VREF_MV_BASE, /* CH0 */
VREF_MV_BASE, /* CH1 */
VREF_MV_BASE, /* CH2 */
VREF_MV_BASE, /* CH3 */
VREF_MV_BASE, /* CH4 */
VREF_MV_BASE, /* CH5 */
VREF_MV_BASE * 2, /* CH6 VDDIO */
VREF_MV_BASE * 4, /* CH7 VBATT */
VREF_MV_BASE, /* CH8 Temp sense 0 */
VREF_MV_BASE, /* CH9 Temp sense 1 */
VREF_MV_BASE, /* CH10 */
VREF_MV_BASE, /* CH11 */
VREF_MV_BASE, /* CH12 USB_DP */
VREF_MV_BASE, /* CH13 USB_DN */
VREF_MV_BASE, /* CH14 VBG */
VREF_MV_BASE * 4, /* CH15 VDD5V */
},
[IMX28_LRADC] = {
VREF_MV_BASE, /* CH0 */
VREF_MV_BASE, /* CH1 */
VREF_MV_BASE, /* CH2 */
VREF_MV_BASE, /* CH3 */
VREF_MV_BASE, /* CH4 */
VREF_MV_BASE, /* CH5 */
VREF_MV_BASE, /* CH6 */
VREF_MV_BASE * 4, /* CH7 VBATT */
VREF_MV_BASE, /* CH8 Temp sense 0 */
VREF_MV_BASE, /* CH9 Temp sense 1 */
VREF_MV_BASE * 2, /* CH10 VDDIO */
VREF_MV_BASE, /* CH11 VTH */
VREF_MV_BASE * 2, /* CH12 VDDA */
VREF_MV_BASE, /* CH13 VDDD */
VREF_MV_BASE, /* CH14 VBG */
VREF_MV_BASE * 4, /* CH15 VDD5V */
},
};
enum mxs_lradc_divbytwo {
MXS_LRADC_DIV_DISABLED = 0,
MXS_LRADC_DIV_ENABLED,
};
struct mxs_lradc_scale {
unsigned int integer;
unsigned int nano;
};
struct mxs_lradc_adc {
struct mxs_lradc *lradc;
struct device *dev;
void __iomem *base;
u32 buffer[10];
struct iio_trigger *trig;
struct completion completion;
spinlock_t lock;
const u32 *vref_mv;
struct mxs_lradc_scale scale_avail[LRADC_MAX_TOTAL_CHANS][2];
unsigned long is_divided;
};
/* Raw I/O operations */
static int mxs_lradc_adc_read_single(struct iio_dev *iio_dev, int chan,
int *val)
{
struct mxs_lradc_adc *adc = iio_priv(iio_dev);
struct mxs_lradc *lradc = adc->lradc;
int ret;
/*
* See if there is no buffered operation in progress. If there is simply
* bail out. This can be improved to support both buffered and raw IO at
* the same time, yet the code becomes horribly complicated. Therefore I
* applied KISS principle here.
*/
ret = iio_device_claim_direct_mode(iio_dev);
if (ret)
return ret;
reinit_completion(&adc->completion);
/*
* No buffered operation in progress, map the channel and trigger it.
* Virtual channel 0 is always used here as the others are always not
* used if doing raw sampling.
*/
if (lradc->soc == IMX28_LRADC)
writel(LRADC_CTRL1_LRADC_IRQ_EN(0),
adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
writel(0x1, adc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
/* Enable / disable the divider per requirement */
if (test_bit(chan, &adc->is_divided))
writel(1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
adc->base + LRADC_CTRL2 + STMP_OFFSET_REG_SET);
else
writel(1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
adc->base + LRADC_CTRL2 + STMP_OFFSET_REG_CLR);
/* Clean the slot's previous content, then set new one. */
writel(LRADC_CTRL4_LRADCSELECT_MASK(0),
adc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
writel(chan, adc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
writel(0, adc->base + LRADC_CH(0));
/* Enable the IRQ and start sampling the channel. */
writel(LRADC_CTRL1_LRADC_IRQ_EN(0),
adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
writel(BIT(0), adc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
/* Wait for completion on the channel, 1 second max. */
ret = wait_for_completion_killable_timeout(&adc->completion, HZ);
if (!ret)
ret = -ETIMEDOUT;
if (ret < 0)
goto err;
/* Read the data. */
*val = readl(adc->base + LRADC_CH(0)) & LRADC_CH_VALUE_MASK;
ret = IIO_VAL_INT;
err:
writel(LRADC_CTRL1_LRADC_IRQ_EN(0),
adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
iio_device_release_direct_mode(iio_dev);
return ret;
}
static int mxs_lradc_adc_read_temp(struct iio_dev *iio_dev, int *val)
{
int ret, min, max;
ret = mxs_lradc_adc_read_single(iio_dev, 8, &min);
if (ret != IIO_VAL_INT)
return ret;
ret = mxs_lradc_adc_read_single(iio_dev, 9, &max);
if (ret != IIO_VAL_INT)
return ret;
*val = max - min;
return IIO_VAL_INT;
}
static int mxs_lradc_adc_read_raw(struct iio_dev *iio_dev,
const struct iio_chan_spec *chan,
int *val, int *val2, long m)
{
struct mxs_lradc_adc *adc = iio_priv(iio_dev);
switch (m) {
case IIO_CHAN_INFO_RAW:
if (chan->type == IIO_TEMP)
return mxs_lradc_adc_read_temp(iio_dev, val);
return mxs_lradc_adc_read_single(iio_dev, chan->channel, val);
case IIO_CHAN_INFO_SCALE:
if (chan->type == IIO_TEMP) {
/*
* From the datasheet, we have to multiply by 1.012 and
* divide by 4
*/
*val = 0;
*val2 = 253000;
return IIO_VAL_INT_PLUS_MICRO;
}
*val = adc->vref_mv[chan->channel];
*val2 = chan->scan_type.realbits -
test_bit(chan->channel, &adc->is_divided);
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_OFFSET:
if (chan->type == IIO_TEMP) {
/*
* The calculated value from the ADC is in Kelvin, we
* want Celsius for hwmon so the offset is -273.15
* The offset is applied before scaling so it is
* actually -213.15 * 4 / 1.012 = -1079.644268
*/
*val = -1079;
*val2 = 644268;
return IIO_VAL_INT_PLUS_MICRO;
}
return -EINVAL;
default:
break;
}
return -EINVAL;
}
static int mxs_lradc_adc_write_raw(struct iio_dev *iio_dev,
const struct iio_chan_spec *chan,
int val, int val2, long m)
{
struct mxs_lradc_adc *adc = iio_priv(iio_dev);
struct mxs_lradc_scale *scale_avail =
adc->scale_avail[chan->channel];
int ret;
ret = iio_device_claim_direct_mode(iio_dev);
if (ret)
return ret;
switch (m) {
case IIO_CHAN_INFO_SCALE:
ret = -EINVAL;
if (val == scale_avail[MXS_LRADC_DIV_DISABLED].integer &&
val2 == scale_avail[MXS_LRADC_DIV_DISABLED].nano) {
/* divider by two disabled */
clear_bit(chan->channel, &adc->is_divided);
ret = 0;
} else if (val == scale_avail[MXS_LRADC_DIV_ENABLED].integer &&
val2 == scale_avail[MXS_LRADC_DIV_ENABLED].nano) {
/* divider by two enabled */
set_bit(chan->channel, &adc->is_divided);
ret = 0;
}
break;
default:
ret = -EINVAL;
break;
}
iio_device_release_direct_mode(iio_dev);
return ret;
}
static int mxs_lradc_adc_write_raw_get_fmt(struct iio_dev *iio_dev,
const struct iio_chan_spec *chan,
long m)
{
return IIO_VAL_INT_PLUS_NANO;
}
static ssize_t mxs_lradc_adc_show_scale_avail(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *iio = dev_to_iio_dev(dev);
struct mxs_lradc_adc *adc = iio_priv(iio);
struct iio_dev_attr *iio_attr = to_iio_dev_attr(attr);
int i, ch, len = 0;
ch = iio_attr->address;
for (i = 0; i < ARRAY_SIZE(adc->scale_avail[ch]); i++)
len += sprintf(buf + len, "%u.%09u ",
adc->scale_avail[ch][i].integer,
adc->scale_avail[ch][i].nano);
len += sprintf(buf + len, "\n");
return len;
}
#define SHOW_SCALE_AVAILABLE_ATTR(ch)\
IIO_DEVICE_ATTR(in_voltage##ch##_scale_available, 0444,\
mxs_lradc_adc_show_scale_avail, NULL, ch)
SHOW_SCALE_AVAILABLE_ATTR(0);
SHOW_SCALE_AVAILABLE_ATTR(1);
SHOW_SCALE_AVAILABLE_ATTR(2);
SHOW_SCALE_AVAILABLE_ATTR(3);
SHOW_SCALE_AVAILABLE_ATTR(4);
SHOW_SCALE_AVAILABLE_ATTR(5);
SHOW_SCALE_AVAILABLE_ATTR(6);
SHOW_SCALE_AVAILABLE_ATTR(7);
SHOW_SCALE_AVAILABLE_ATTR(10);
SHOW_SCALE_AVAILABLE_ATTR(11);
SHOW_SCALE_AVAILABLE_ATTR(12);
SHOW_SCALE_AVAILABLE_ATTR(13);
SHOW_SCALE_AVAILABLE_ATTR(14);
SHOW_SCALE_AVAILABLE_ATTR(15);
static struct attribute *mxs_lradc_adc_attributes[] = {
&iio_dev_attr_in_voltage0_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage1_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage2_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage3_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage4_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage5_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage6_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage7_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage10_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage11_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage12_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage13_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage14_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage15_scale_available.dev_attr.attr,
NULL
};
static const struct attribute_group mxs_lradc_adc_attribute_group = {
.attrs = mxs_lradc_adc_attributes,
};
static const struct iio_info mxs_lradc_adc_iio_info = {
.driver_module = THIS_MODULE,
.read_raw = mxs_lradc_adc_read_raw,
.write_raw = mxs_lradc_adc_write_raw,
.write_raw_get_fmt = mxs_lradc_adc_write_raw_get_fmt,
.attrs = &mxs_lradc_adc_attribute_group,
};
/* IRQ Handling */
static irqreturn_t mxs_lradc_adc_handle_irq(int irq, void *data)
{
struct iio_dev *iio = data;
struct mxs_lradc_adc *adc = iio_priv(iio);
struct mxs_lradc *lradc = adc->lradc;
unsigned long reg = readl(adc->base + LRADC_CTRL1);
unsigned long flags;
if (!(reg & mxs_lradc_irq_mask(lradc)))
return IRQ_NONE;
if (iio_buffer_enabled(iio)) {
if (reg & lradc->buffer_vchans) {
spin_lock_irqsave(&adc->lock, flags);
iio_trigger_poll(iio->trig);
spin_unlock_irqrestore(&adc->lock, flags);
}
} else if (reg & LRADC_CTRL1_LRADC_IRQ(0)) {
complete(&adc->completion);
}
writel(reg & mxs_lradc_irq_mask(lradc),
adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
return IRQ_HANDLED;
}
/* Trigger handling */
static irqreturn_t mxs_lradc_adc_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *iio = pf->indio_dev;
struct mxs_lradc_adc *adc = iio_priv(iio);
const u32 chan_value = LRADC_CH_ACCUMULATE |
((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET);
unsigned int i, j = 0;
for_each_set_bit(i, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) {
adc->buffer[j] = readl(adc->base + LRADC_CH(j));
writel(chan_value, adc->base + LRADC_CH(j));
adc->buffer[j] &= LRADC_CH_VALUE_MASK;
adc->buffer[j] /= LRADC_DELAY_TIMER_LOOP;
j++;
}
iio_push_to_buffers_with_timestamp(iio, adc->buffer, pf->timestamp);
iio_trigger_notify_done(iio->trig);
return IRQ_HANDLED;
}
static int mxs_lradc_adc_configure_trigger(struct iio_trigger *trig, bool state)
{
struct iio_dev *iio = iio_trigger_get_drvdata(trig);
struct mxs_lradc_adc *adc = iio_priv(iio);
const u32 st = state ? STMP_OFFSET_REG_SET : STMP_OFFSET_REG_CLR;
writel(LRADC_DELAY_KICK, adc->base + (LRADC_DELAY(0) + st));
return 0;
}
static const struct iio_trigger_ops mxs_lradc_adc_trigger_ops = {
.owner = THIS_MODULE,
.set_trigger_state = &mxs_lradc_adc_configure_trigger,
};
static int mxs_lradc_adc_trigger_init(struct iio_dev *iio)
{
int ret;
struct iio_trigger *trig;
struct mxs_lradc_adc *adc = iio_priv(iio);
trig = devm_iio_trigger_alloc(&iio->dev, "%s-dev%i", iio->name,
iio->id);
trig->dev.parent = adc->dev;
iio_trigger_set_drvdata(trig, iio);
trig->ops = &mxs_lradc_adc_trigger_ops;
ret = iio_trigger_register(trig);
if (ret)
return ret;
adc->trig = trig;
return 0;
}
static void mxs_lradc_adc_trigger_remove(struct iio_dev *iio)
{
struct mxs_lradc_adc *adc = iio_priv(iio);
iio_trigger_unregister(adc->trig);
}
static int mxs_lradc_adc_buffer_preenable(struct iio_dev *iio)
{
struct mxs_lradc_adc *adc = iio_priv(iio);
struct mxs_lradc *lradc = adc->lradc;
int chan, ofs = 0;
unsigned long enable = 0;
u32 ctrl4_set = 0;
u32 ctrl4_clr = 0;
u32 ctrl1_irq = 0;
const u32 chan_value = LRADC_CH_ACCUMULATE |
((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET);
if (lradc->soc == IMX28_LRADC)
writel(lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
writel(lradc->buffer_vchans,
adc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
for_each_set_bit(chan, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) {
ctrl4_set |= chan << LRADC_CTRL4_LRADCSELECT_OFFSET(ofs);
ctrl4_clr |= LRADC_CTRL4_LRADCSELECT_MASK(ofs);
ctrl1_irq |= LRADC_CTRL1_LRADC_IRQ_EN(ofs);
writel(chan_value, adc->base + LRADC_CH(ofs));
bitmap_set(&enable, ofs, 1);
ofs++;
}
writel(LRADC_DELAY_TRIGGER_LRADCS_MASK | LRADC_DELAY_KICK,
adc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_CLR);
writel(ctrl4_clr, adc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
writel(ctrl4_set, adc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
writel(ctrl1_irq, adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
writel(enable << LRADC_DELAY_TRIGGER_LRADCS_OFFSET,
adc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_SET);
return 0;
}
static int mxs_lradc_adc_buffer_postdisable(struct iio_dev *iio)
{
struct mxs_lradc_adc *adc = iio_priv(iio);
struct mxs_lradc *lradc = adc->lradc;
writel(LRADC_DELAY_TRIGGER_LRADCS_MASK | LRADC_DELAY_KICK,
adc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_CLR);
writel(lradc->buffer_vchans,
adc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
if (lradc->soc == IMX28_LRADC)
writel(lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
adc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
return 0;
}
static bool mxs_lradc_adc_validate_scan_mask(struct iio_dev *iio,
const unsigned long *mask)
{
struct mxs_lradc_adc *adc = iio_priv(iio);
struct mxs_lradc *lradc = adc->lradc;
const int map_chans = bitmap_weight(mask, LRADC_MAX_TOTAL_CHANS);
int rsvd_chans = 0;
unsigned long rsvd_mask = 0;
if (lradc->use_touchbutton)
rsvd_mask |= CHAN_MASK_TOUCHBUTTON;
if (lradc->touchscreen_wire == MXS_LRADC_TOUCHSCREEN_4WIRE)
rsvd_mask |= CHAN_MASK_TOUCHSCREEN_4WIRE;
if (lradc->touchscreen_wire == MXS_LRADC_TOUCHSCREEN_5WIRE)
rsvd_mask |= CHAN_MASK_TOUCHSCREEN_5WIRE;
if (lradc->use_touchbutton)
rsvd_chans++;
if (lradc->touchscreen_wire)
rsvd_chans += 2;
/* Test for attempts to map channels with special mode of operation. */
if (bitmap_intersects(mask, &rsvd_mask, LRADC_MAX_TOTAL_CHANS))
return false;
/* Test for attempts to map more channels then available slots. */
if (map_chans + rsvd_chans > LRADC_MAX_MAPPED_CHANS)
return false;
return true;
}
static const struct iio_buffer_setup_ops mxs_lradc_adc_buffer_ops = {
.preenable = &mxs_lradc_adc_buffer_preenable,
.postenable = &iio_triggered_buffer_postenable,
.predisable = &iio_triggered_buffer_predisable,
.postdisable = &mxs_lradc_adc_buffer_postdisable,
.validate_scan_mask = &mxs_lradc_adc_validate_scan_mask,
};
/* Driver initialization */
#define MXS_ADC_CHAN(idx, chan_type, name) { \
.type = (chan_type), \
.indexed = 1, \
.scan_index = (idx), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE), \
.channel = (idx), \
.address = (idx), \
.scan_type = { \
.sign = 'u', \
.realbits = LRADC_RESOLUTION, \
.storagebits = 32, \
}, \
.datasheet_name = (name), \
}
static const struct iio_chan_spec mx23_lradc_chan_spec[] = {
MXS_ADC_CHAN(0, IIO_VOLTAGE, "LRADC0"),
MXS_ADC_CHAN(1, IIO_VOLTAGE, "LRADC1"),
MXS_ADC_CHAN(2, IIO_VOLTAGE, "LRADC2"),
MXS_ADC_CHAN(3, IIO_VOLTAGE, "LRADC3"),
MXS_ADC_CHAN(4, IIO_VOLTAGE, "LRADC4"),
MXS_ADC_CHAN(5, IIO_VOLTAGE, "LRADC5"),
MXS_ADC_CHAN(6, IIO_VOLTAGE, "VDDIO"),
MXS_ADC_CHAN(7, IIO_VOLTAGE, "VBATT"),
/* Combined Temperature sensors */
{
.type = IIO_TEMP,
.indexed = 1,
.scan_index = 8,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_OFFSET) |
BIT(IIO_CHAN_INFO_SCALE),
.channel = 8,
.scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
.datasheet_name = "TEMP_DIE",
},
/* Hidden channel to keep indexes */
{
.type = IIO_TEMP,
.indexed = 1,
.scan_index = -1,
.channel = 9,
},
MXS_ADC_CHAN(10, IIO_VOLTAGE, NULL),
MXS_ADC_CHAN(11, IIO_VOLTAGE, NULL),
MXS_ADC_CHAN(12, IIO_VOLTAGE, "USB_DP"),
MXS_ADC_CHAN(13, IIO_VOLTAGE, "USB_DN"),
MXS_ADC_CHAN(14, IIO_VOLTAGE, "VBG"),
MXS_ADC_CHAN(15, IIO_VOLTAGE, "VDD5V"),
};
static const struct iio_chan_spec mx28_lradc_chan_spec[] = {
MXS_ADC_CHAN(0, IIO_VOLTAGE, "LRADC0"),
MXS_ADC_CHAN(1, IIO_VOLTAGE, "LRADC1"),
MXS_ADC_CHAN(2, IIO_VOLTAGE, "LRADC2"),
MXS_ADC_CHAN(3, IIO_VOLTAGE, "LRADC3"),
MXS_ADC_CHAN(4, IIO_VOLTAGE, "LRADC4"),
MXS_ADC_CHAN(5, IIO_VOLTAGE, "LRADC5"),
MXS_ADC_CHAN(6, IIO_VOLTAGE, "LRADC6"),
MXS_ADC_CHAN(7, IIO_VOLTAGE, "VBATT"),
/* Combined Temperature sensors */
{
.type = IIO_TEMP,
.indexed = 1,
.scan_index = 8,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_OFFSET) |
BIT(IIO_CHAN_INFO_SCALE),
.channel = 8,
.scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
.datasheet_name = "TEMP_DIE",
},
/* Hidden channel to keep indexes */
{
.type = IIO_TEMP,
.indexed = 1,
.scan_index = -1,
.channel = 9,
},
MXS_ADC_CHAN(10, IIO_VOLTAGE, "VDDIO"),
MXS_ADC_CHAN(11, IIO_VOLTAGE, "VTH"),
MXS_ADC_CHAN(12, IIO_VOLTAGE, "VDDA"),
MXS_ADC_CHAN(13, IIO_VOLTAGE, "VDDD"),
MXS_ADC_CHAN(14, IIO_VOLTAGE, "VBG"),
MXS_ADC_CHAN(15, IIO_VOLTAGE, "VDD5V"),
};
static void mxs_lradc_adc_hw_init(struct mxs_lradc_adc *adc)
{
/* The ADC always uses DELAY CHANNEL 0. */
const u32 adc_cfg =
(1 << (LRADC_DELAY_TRIGGER_DELAYS_OFFSET + 0)) |
(LRADC_DELAY_TIMER_PER << LRADC_DELAY_DELAY_OFFSET);
/* Configure DELAY CHANNEL 0 for generic ADC sampling. */
writel(adc_cfg, adc->base + LRADC_DELAY(0));
/*
* Start internal temperature sensing by clearing bit
* HW_LRADC_CTRL2_TEMPSENSE_PWD. This bit can be left cleared
* after power up.
*/
writel(0, adc->base + LRADC_CTRL2);
}
static void mxs_lradc_adc_hw_stop(struct mxs_lradc_adc *adc)
{
writel(0, adc->base + LRADC_DELAY(0));
}
static int mxs_lradc_adc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct mxs_lradc *lradc = dev_get_drvdata(dev->parent);
struct mxs_lradc_adc *adc;
struct iio_dev *iio;
struct resource *iores;
int ret, irq, virq, i, s, n;
u64 scale_uv;
const char **irq_name;
/* Allocate the IIO device. */
iio = devm_iio_device_alloc(dev, sizeof(*adc));
if (!iio) {
dev_err(dev, "Failed to allocate IIO device\n");
return -ENOMEM;
}
adc = iio_priv(iio);
adc->lradc = lradc;
adc->dev = dev;
iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
adc->base = devm_ioremap(dev, iores->start, resource_size(iores));
if (IS_ERR(adc->base))
return PTR_ERR(adc->base);
init_completion(&adc->completion);
spin_lock_init(&adc->lock);
platform_set_drvdata(pdev, iio);
iio->name = pdev->name;
iio->dev.parent = dev;
iio->dev.of_node = dev->parent->of_node;
iio->info = &mxs_lradc_adc_iio_info;
iio->modes = INDIO_DIRECT_MODE;
iio->masklength = LRADC_MAX_TOTAL_CHANS;
if (lradc->soc == IMX23_LRADC) {
iio->channels = mx23_lradc_chan_spec;
iio->num_channels = ARRAY_SIZE(mx23_lradc_chan_spec);
irq_name = mx23_lradc_adc_irq_names;
n = ARRAY_SIZE(mx23_lradc_adc_irq_names);
} else {
iio->channels = mx28_lradc_chan_spec;
iio->num_channels = ARRAY_SIZE(mx28_lradc_chan_spec);
irq_name = mx28_lradc_adc_irq_names;
n = ARRAY_SIZE(mx28_lradc_adc_irq_names);
}
ret = stmp_reset_block(adc->base);
if (ret)
return ret;
for (i = 0; i < n; i++) {
irq = platform_get_irq_byname(pdev, irq_name[i]);
if (irq < 0)
return irq;
virq = irq_of_parse_and_map(dev->parent->of_node, irq);
ret = devm_request_irq(dev, virq, mxs_lradc_adc_handle_irq,
0, irq_name[i], iio);
if (ret)
return ret;
}
ret = mxs_lradc_adc_trigger_init(iio);
if (ret)
goto err_trig;
ret = iio_triggered_buffer_setup(iio, &iio_pollfunc_store_time,
&mxs_lradc_adc_trigger_handler,
&mxs_lradc_adc_buffer_ops);
if (ret)
return ret;
adc->vref_mv = mxs_lradc_adc_vref_mv[lradc->soc];
/* Populate available ADC input ranges */
for (i = 0; i < LRADC_MAX_TOTAL_CHANS; i++) {
for (s = 0; s < ARRAY_SIZE(adc->scale_avail[i]); s++) {
/*
* [s=0] = optional divider by two disabled (default)
* [s=1] = optional divider by two enabled
*
* The scale is calculated by doing:
* Vref >> (realbits - s)
* which multiplies by two on the second component
* of the array.
*/
scale_uv = ((u64)adc->vref_mv[i] * 100000000) >>
(LRADC_RESOLUTION - s);
adc->scale_avail[i][s].nano =
do_div(scale_uv, 100000000) * 10;
adc->scale_avail[i][s].integer = scale_uv;
}
}
/* Configure the hardware. */
mxs_lradc_adc_hw_init(adc);
/* Register IIO device. */
ret = iio_device_register(iio);
if (ret) {
dev_err(dev, "Failed to register IIO device\n");
goto err_dev;
}
return 0;
err_dev:
mxs_lradc_adc_hw_stop(adc);
mxs_lradc_adc_trigger_remove(iio);
err_trig:
iio_triggered_buffer_cleanup(iio);
return ret;
}
static int mxs_lradc_adc_remove(struct platform_device *pdev)
{
struct iio_dev *iio = platform_get_drvdata(pdev);
struct mxs_lradc_adc *adc = iio_priv(iio);
iio_device_unregister(iio);
mxs_lradc_adc_hw_stop(adc);
mxs_lradc_adc_trigger_remove(iio);
iio_triggered_buffer_cleanup(iio);
return 0;
}
static struct platform_driver mxs_lradc_adc_driver = {
.driver = {
.name = "mxs-lradc-adc",
},
.probe = mxs_lradc_adc_probe,
.remove = mxs_lradc_adc_remove,
};
module_platform_driver(mxs_lradc_adc_driver);
MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
MODULE_DESCRIPTION("Freescale MXS LRADC driver general purpose ADC driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:mxs-lradc-adc");