// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2014-2015 Pengutronix, Markus Pargmann <[email protected]>
*
* This is the driver for the imx25 GCQ (Generic Conversion Queue)
* connected to the imx25 ADC.
*/
#include <dt-bindings/iio/adc/fsl-imx25-gcq.h>
#include <linux/clk.h>
#include <linux/iio/iio.h>
#include <linux/interrupt.h>
#include <linux/mfd/imx25-tsadc.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#define MX25_GCQ_TIMEOUT (msecs_to_jiffies(2000))
static const char * const driver_name = "mx25-gcq";
enum mx25_gcq_cfgs {
MX25_CFG_XP = 0,
MX25_CFG_YP,
MX25_CFG_XN,
MX25_CFG_YN,
MX25_CFG_WIPER,
MX25_CFG_INAUX0,
MX25_CFG_INAUX1,
MX25_CFG_INAUX2,
MX25_NUM_CFGS,
};
struct mx25_gcq_priv {
struct regmap *regs;
struct completion completed;
struct clk *clk;
int irq;
struct regulator *vref[4];
u32 channel_vref_mv[MX25_NUM_CFGS];
/*
* Lock to protect the device state during a potential concurrent
* read access from userspace. Reading a raw value requires a sequence
* of register writes, then a wait for a completion callback,
* and finally a register read, during which userspace could issue
* another read request. This lock protects a read access from
* ocurring before another one has finished.
*/
struct mutex lock;
};
#define MX25_CQG_CHAN(chan, id) {\
.type = IIO_VOLTAGE,\
.indexed = 1,\
.channel = chan,\
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE),\
.datasheet_name = id,\
}
static const struct iio_chan_spec mx25_gcq_channels[MX25_NUM_CFGS] = {
MX25_CQG_CHAN(MX25_CFG_XP, "xp"),
MX25_CQG_CHAN(MX25_CFG_YP, "yp"),
MX25_CQG_CHAN(MX25_CFG_XN, "xn"),
MX25_CQG_CHAN(MX25_CFG_YN, "yn"),
MX25_CQG_CHAN(MX25_CFG_WIPER, "wiper"),
MX25_CQG_CHAN(MX25_CFG_INAUX0, "inaux0"),
MX25_CQG_CHAN(MX25_CFG_INAUX1, "inaux1"),
MX25_CQG_CHAN(MX25_CFG_INAUX2, "inaux2"),
};
static const char * const mx25_gcq_refp_names[] = {
[MX25_ADC_REFP_YP] = "yp",
[MX25_ADC_REFP_XP] = "xp",
[MX25_ADC_REFP_INT] = "int",
[MX25_ADC_REFP_EXT] = "ext",
};
static irqreturn_t mx25_gcq_irq(int irq, void *data)
{
struct mx25_gcq_priv *priv = data;
u32 stats;
regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
if (stats & MX25_ADCQ_SR_EOQ) {
regmap_set_bits(priv->regs, MX25_ADCQ_MR,
MX25_ADCQ_MR_EOQ_IRQ);
complete(&priv->completed);
}
/* Disable conversion queue run */
regmap_clear_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS);
/* Acknowledge all possible irqs */
regmap_write(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_FRR |
MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR |
MX25_ADCQ_SR_EOQ | MX25_ADCQ_SR_PD);
return IRQ_HANDLED;
}
static int mx25_gcq_get_raw_value(struct device *dev,
struct iio_chan_spec const *chan,
struct mx25_gcq_priv *priv,
int *val)
{
long time_left;
u32 data;
/* Setup the configuration we want to use */
regmap_write(priv->regs, MX25_ADCQ_ITEM_7_0,
MX25_ADCQ_ITEM(0, chan->channel));
regmap_clear_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_EOQ_IRQ);
/* Trigger queue for one run */
regmap_set_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS);
time_left = wait_for_completion_interruptible_timeout(
&priv->completed, MX25_GCQ_TIMEOUT);
if (time_left < 0) {
dev_err(dev, "ADC wait for measurement failed\n");
return time_left;
} else if (time_left == 0) {
dev_err(dev, "ADC timed out\n");
return -ETIMEDOUT;
}
regmap_read(priv->regs, MX25_ADCQ_FIFO, &data);
*val = MX25_ADCQ_FIFO_DATA(data);
return IIO_VAL_INT;
}
static int mx25_gcq_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val,
int *val2, long mask)
{
struct mx25_gcq_priv *priv = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
mutex_lock(&priv->lock);
ret = mx25_gcq_get_raw_value(&indio_dev->dev, chan, priv, val);
mutex_unlock(&priv->lock);
return ret;
case IIO_CHAN_INFO_SCALE:
*val = priv->channel_vref_mv[chan->channel];
*val2 = 12;
return IIO_VAL_FRACTIONAL_LOG2;
default:
return -EINVAL;
}
}
static const struct iio_info mx25_gcq_iio_info = {
.read_raw = mx25_gcq_read_raw,
};
static const struct regmap_config mx25_gcq_regconfig = {
.max_register = 0x5c,
.reg_bits = 32,
.val_bits = 32,
.reg_stride = 4,
};
static int mx25_gcq_ext_regulator_setup(struct device *dev,
struct mx25_gcq_priv *priv, u32 refp)
{
char reg_name[12];
int ret;
if (priv->vref[refp])
return 0;
ret = snprintf(reg_name, sizeof(reg_name), "vref-%s",
mx25_gcq_refp_names[refp]);
if (ret < 0)
return ret;
priv->vref[refp] = devm_regulator_get_optional(dev, reg_name);
if (IS_ERR(priv->vref[refp]))
return dev_err_probe(dev, PTR_ERR(priv->vref[refp]),
"Error, trying to use external voltage reference without a %s regulator.",
reg_name);
return 0;
}
static int mx25_gcq_setup_cfgs(struct platform_device *pdev,
struct mx25_gcq_priv *priv)
{
struct device *dev = &pdev->dev;
int ret, i;
/*
* Setup all configurations registers with a default conversion
* configuration for each input
*/
for (i = 0; i < MX25_NUM_CFGS; ++i)
regmap_write(priv->regs, MX25_ADCQ_CFG(i),
MX25_ADCQ_CFG_YPLL_OFF |
MX25_ADCQ_CFG_XNUR_OFF |
MX25_ADCQ_CFG_XPUL_OFF |
MX25_ADCQ_CFG_REFP_INT |
MX25_ADCQ_CFG_IN(i) |
MX25_ADCQ_CFG_REFN_NGND2);
device_for_each_child_node_scoped(dev, child) {
u32 reg;
u32 refp = MX25_ADCQ_CFG_REFP_INT;
u32 refn = MX25_ADCQ_CFG_REFN_NGND2;
ret = fwnode_property_read_u32(child, "reg", ®);
if (ret)
return dev_err_probe(dev, ret,
"Failed to get reg property\n");
if (reg >= MX25_NUM_CFGS)
return dev_err_probe(dev, -EINVAL,
"reg value is greater than the number of available configuration registers\n");
fwnode_property_read_u32(child, "fsl,adc-refp", &refp);
fwnode_property_read_u32(child, "fsl,adc-refn", &refn);
switch (refp) {
case MX25_ADC_REFP_EXT:
case MX25_ADC_REFP_XP:
case MX25_ADC_REFP_YP:
ret = mx25_gcq_ext_regulator_setup(&pdev->dev, priv, refp);
if (ret)
return ret;
priv->channel_vref_mv[reg] =
regulator_get_voltage(priv->vref[refp]);
/* Conversion from uV to mV */
priv->channel_vref_mv[reg] /= 1000;
break;
case MX25_ADC_REFP_INT:
priv->channel_vref_mv[reg] = 2500;
break;
default:
return dev_err_probe(dev, -EINVAL,
"Invalid positive reference %d\n", refp);
}
/*
* Shift the read values to the correct positions within the
* register.
*/
refp = MX25_ADCQ_CFG_REFP(refp);
refn = MX25_ADCQ_CFG_REFN(refn);
if ((refp & MX25_ADCQ_CFG_REFP_MASK) != refp)
return dev_err_probe(dev, -EINVAL,
"Invalid fsl,adc-refp property value\n");
if ((refn & MX25_ADCQ_CFG_REFN_MASK) != refn)
return dev_err_probe(dev, -EINVAL,
"Invalid fsl,adc-refn property value\n");
regmap_update_bits(priv->regs, MX25_ADCQ_CFG(reg),
MX25_ADCQ_CFG_REFP_MASK |
MX25_ADCQ_CFG_REFN_MASK,
refp | refn);
}
regmap_set_bits(priv->regs, MX25_ADCQ_CR,
MX25_ADCQ_CR_FRST | MX25_ADCQ_CR_QRST);
regmap_write(priv->regs, MX25_ADCQ_CR,
MX25_ADCQ_CR_PDMSK | MX25_ADCQ_CR_QSM_FQS);
return 0;
}
static void mx25_gcq_reg_disable(void *reg)
{
regulator_disable(reg);
}
/* Custom handling needed as this driver doesn't own the clock */
static void mx25_gcq_clk_disable(void *clk)
{
clk_disable_unprepare(clk);
}
static int mx25_gcq_probe(struct platform_device *pdev)
{
struct iio_dev *indio_dev;
struct mx25_gcq_priv *priv;
struct mx25_tsadc *tsadc = dev_get_drvdata(pdev->dev.parent);
struct device *dev = &pdev->dev;
void __iomem *mem;
int ret;
int i;
indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
if (!indio_dev)
return -ENOMEM;
priv = iio_priv(indio_dev);
mem = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(mem))
return PTR_ERR(mem);
priv->regs = devm_regmap_init_mmio(dev, mem, &mx25_gcq_regconfig);
if (IS_ERR(priv->regs))
return dev_err_probe(dev, PTR_ERR(priv->regs),
"Failed to initialize regmap\n");
mutex_init(&priv->lock);
init_completion(&priv->completed);
ret = mx25_gcq_setup_cfgs(pdev, priv);
if (ret)
return ret;
for (i = 0; i != 4; ++i) {
if (!priv->vref[i])
continue;
ret = regulator_enable(priv->vref[i]);
if (ret)
return ret;
ret = devm_add_action_or_reset(dev, mx25_gcq_reg_disable,
priv->vref[i]);
if (ret)
return ret;
}
priv->clk = tsadc->clk;
ret = clk_prepare_enable(priv->clk);
if (ret)
return dev_err_probe(dev, ret, "Failed to enable clock\n");
ret = devm_add_action_or_reset(dev, mx25_gcq_clk_disable,
priv->clk);
if (ret)
return ret;
ret = platform_get_irq(pdev, 0);
if (ret < 0)
return ret;
priv->irq = ret;
ret = devm_request_irq(dev, priv->irq, mx25_gcq_irq, 0, pdev->name,
priv);
if (ret)
return dev_err_probe(dev, ret, "Failed requesting IRQ\n");
indio_dev->channels = mx25_gcq_channels;
indio_dev->num_channels = ARRAY_SIZE(mx25_gcq_channels);
indio_dev->info = &mx25_gcq_iio_info;
indio_dev->name = driver_name;
ret = devm_iio_device_register(dev, indio_dev);
if (ret)
return dev_err_probe(dev, ret, "Failed to register iio device\n");
return 0;
}
static const struct of_device_id mx25_gcq_ids[] = {
{ .compatible = "fsl,imx25-gcq", },
{ /* Sentinel */ }
};
MODULE_DEVICE_TABLE(of, mx25_gcq_ids);
static struct platform_driver mx25_gcq_driver = {
.driver = {
.name = "mx25-gcq",
.of_match_table = mx25_gcq_ids,
},
.probe = mx25_gcq_probe,
};
module_platform_driver(mx25_gcq_driver);
MODULE_DESCRIPTION("ADC driver for Freescale mx25");
MODULE_AUTHOR("Markus Pargmann <[email protected]>");
MODULE_LICENSE("GPL v2");
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