blob: 44e1e53ada729490bf6277c9252e93189e821c16 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2016 Broadcom
*/
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/iio/iio.h>
/* Below Register's are common to IPROC ADC and Touchscreen IP */
#define IPROC_REGCTL1 0x00
#define IPROC_REGCTL2 0x04
#define IPROC_INTERRUPT_THRES 0x08
#define IPROC_INTERRUPT_MASK 0x0c
#define IPROC_INTERRUPT_STATUS 0x10
#define IPROC_ANALOG_CONTROL 0x1c
#define IPROC_CONTROLLER_STATUS 0x14
#define IPROC_AUX_DATA 0x20
#define IPROC_SOFT_BYPASS_CONTROL 0x38
#define IPROC_SOFT_BYPASS_DATA 0x3C
/* IPROC ADC Channel register offsets */
#define IPROC_ADC_CHANNEL_REGCTL1 0x800
#define IPROC_ADC_CHANNEL_REGCTL2 0x804
#define IPROC_ADC_CHANNEL_STATUS 0x808
#define IPROC_ADC_CHANNEL_INTERRUPT_STATUS 0x80c
#define IPROC_ADC_CHANNEL_INTERRUPT_MASK 0x810
#define IPROC_ADC_CHANNEL_DATA 0x814
#define IPROC_ADC_CHANNEL_OFFSET 0x20
/* Bit definitions for IPROC_REGCTL2 */
#define IPROC_ADC_AUXIN_SCAN_ENA BIT(0)
#define IPROC_ADC_PWR_LDO BIT(5)
#define IPROC_ADC_PWR_ADC BIT(4)
#define IPROC_ADC_PWR_BG BIT(3)
#define IPROC_ADC_CONTROLLER_EN BIT(17)
/* Bit definitions for IPROC_INTERRUPT_MASK and IPROC_INTERRUPT_STATUS */
#define IPROC_ADC_AUXDATA_RDY_INTR BIT(3)
#define IPROC_ADC_INTR 9
#define IPROC_ADC_INTR_MASK (0xFF << IPROC_ADC_INTR)
/* Bit definitions for IPROC_ANALOG_CONTROL */
#define IPROC_ADC_CHANNEL_SEL 11
#define IPROC_ADC_CHANNEL_SEL_MASK (0x7 << IPROC_ADC_CHANNEL_SEL)
/* Bit definitions for IPROC_ADC_CHANNEL_REGCTL1 */
#define IPROC_ADC_CHANNEL_ROUNDS 0x2
#define IPROC_ADC_CHANNEL_ROUNDS_MASK (0x3F << IPROC_ADC_CHANNEL_ROUNDS)
#define IPROC_ADC_CHANNEL_MODE 0x1
#define IPROC_ADC_CHANNEL_MODE_MASK (0x1 << IPROC_ADC_CHANNEL_MODE)
#define IPROC_ADC_CHANNEL_MODE_TDM 0x1
#define IPROC_ADC_CHANNEL_MODE_SNAPSHOT 0x0
#define IPROC_ADC_CHANNEL_ENABLE 0x0
#define IPROC_ADC_CHANNEL_ENABLE_MASK 0x1
/* Bit definitions for IPROC_ADC_CHANNEL_REGCTL2 */
#define IPROC_ADC_CHANNEL_WATERMARK 0x0
#define IPROC_ADC_CHANNEL_WATERMARK_MASK \
(0x3F << IPROC_ADC_CHANNEL_WATERMARK)
#define IPROC_ADC_WATER_MARK_LEVEL 0x1
/* Bit definitions for IPROC_ADC_CHANNEL_STATUS */
#define IPROC_ADC_CHANNEL_DATA_LOST 0x0
#define IPROC_ADC_CHANNEL_DATA_LOST_MASK \
(0x0 << IPROC_ADC_CHANNEL_DATA_LOST)
#define IPROC_ADC_CHANNEL_VALID_ENTERIES 0x1
#define IPROC_ADC_CHANNEL_VALID_ENTERIES_MASK \
(0xFF << IPROC_ADC_CHANNEL_VALID_ENTERIES)
#define IPROC_ADC_CHANNEL_TOTAL_ENTERIES 0x9
#define IPROC_ADC_CHANNEL_TOTAL_ENTERIES_MASK \
(0xFF << IPROC_ADC_CHANNEL_TOTAL_ENTERIES)
/* Bit definitions for IPROC_ADC_CHANNEL_INTERRUPT_MASK */
#define IPROC_ADC_CHANNEL_WTRMRK_INTR 0x0
#define IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK \
(0x1 << IPROC_ADC_CHANNEL_WTRMRK_INTR)
#define IPROC_ADC_CHANNEL_FULL_INTR 0x1
#define IPROC_ADC_CHANNEL_FULL_INTR_MASK \
(0x1 << IPROC_ADC_IPROC_ADC_CHANNEL_FULL_INTR)
#define IPROC_ADC_CHANNEL_EMPTY_INTR 0x2
#define IPROC_ADC_CHANNEL_EMPTY_INTR_MASK \
(0x1 << IPROC_ADC_CHANNEL_EMPTY_INTR)
#define IPROC_ADC_WATER_MARK_INTR_ENABLE 0x1
/* Number of time to retry a set of the interrupt mask reg */
#define IPROC_ADC_INTMASK_RETRY_ATTEMPTS 10
#define IPROC_ADC_READ_TIMEOUT (HZ*2)
#define iproc_adc_dbg_reg(dev, priv, reg) \
do { \
u32 val; \
regmap_read(priv->regmap, reg, &val); \
dev_dbg(dev, "%20s= 0x%08x\n", #reg, val); \
} while (0)
struct iproc_adc_priv {
struct regmap *regmap;
struct clk *adc_clk;
struct mutex mutex;
int irqno;
int chan_val;
int chan_id;
struct completion completion;
};
static void iproc_adc_reg_dump(struct iio_dev *indio_dev)
{
struct device *dev = &indio_dev->dev;
struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
iproc_adc_dbg_reg(dev, adc_priv, IPROC_REGCTL1);
iproc_adc_dbg_reg(dev, adc_priv, IPROC_REGCTL2);
iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_THRES);
iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_MASK);
iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_STATUS);
iproc_adc_dbg_reg(dev, adc_priv, IPROC_CONTROLLER_STATUS);
iproc_adc_dbg_reg(dev, adc_priv, IPROC_ANALOG_CONTROL);
iproc_adc_dbg_reg(dev, adc_priv, IPROC_AUX_DATA);
iproc_adc_dbg_reg(dev, adc_priv, IPROC_SOFT_BYPASS_CONTROL);
iproc_adc_dbg_reg(dev, adc_priv, IPROC_SOFT_BYPASS_DATA);
}
static irqreturn_t iproc_adc_interrupt_thread(int irq, void *data)
{
u32 channel_intr_status;
u32 intr_status;
u32 intr_mask;
struct iio_dev *indio_dev = data;
struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
/*
* This interrupt is shared with the touchscreen driver.
* Make sure this interrupt is intended for us.
* Handle only ADC channel specific interrupts.
*/
regmap_read(adc_priv->regmap, IPROC_INTERRUPT_STATUS, &intr_status);
regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &intr_mask);
intr_status = intr_status & intr_mask;
channel_intr_status = (intr_status & IPROC_ADC_INTR_MASK) >>
IPROC_ADC_INTR;
if (channel_intr_status)
return IRQ_WAKE_THREAD;
return IRQ_NONE;
}
static irqreturn_t iproc_adc_interrupt_handler(int irq, void *data)
{
irqreturn_t retval = IRQ_NONE;
struct iproc_adc_priv *adc_priv;
struct iio_dev *indio_dev = data;
unsigned int valid_entries;
u32 intr_status;
u32 intr_channels;
u32 channel_status;
u32 ch_intr_status;
adc_priv = iio_priv(indio_dev);
regmap_read(adc_priv->regmap, IPROC_INTERRUPT_STATUS, &intr_status);
dev_dbg(&indio_dev->dev, "iproc_adc_interrupt_handler(),INTRPT_STS:%x\n",
intr_status);
intr_channels = (intr_status & IPROC_ADC_INTR_MASK) >> IPROC_ADC_INTR;
if (intr_channels) {
regmap_read(adc_priv->regmap,
IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
IPROC_ADC_CHANNEL_OFFSET * adc_priv->chan_id,
&ch_intr_status);
if (ch_intr_status & IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK) {
regmap_read(adc_priv->regmap,
IPROC_ADC_CHANNEL_STATUS +
IPROC_ADC_CHANNEL_OFFSET *
adc_priv->chan_id,
&channel_status);
valid_entries = ((channel_status &
IPROC_ADC_CHANNEL_VALID_ENTERIES_MASK) >>
IPROC_ADC_CHANNEL_VALID_ENTERIES);
if (valid_entries >= 1) {
regmap_read(adc_priv->regmap,
IPROC_ADC_CHANNEL_DATA +
IPROC_ADC_CHANNEL_OFFSET *
adc_priv->chan_id,
&adc_priv->chan_val);
complete(&adc_priv->completion);
} else {
dev_err(&indio_dev->dev,
"No data rcvd on channel %d\n",
adc_priv->chan_id);
}
regmap_write(adc_priv->regmap,
IPROC_ADC_CHANNEL_INTERRUPT_MASK +
IPROC_ADC_CHANNEL_OFFSET *
adc_priv->chan_id,
(ch_intr_status &
~(IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK)));
}
regmap_write(adc_priv->regmap,
IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
IPROC_ADC_CHANNEL_OFFSET * adc_priv->chan_id,
ch_intr_status);
regmap_write(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
intr_channels);
retval = IRQ_HANDLED;
}
return retval;
}
static int iproc_adc_do_read(struct iio_dev *indio_dev,
int channel,
u16 *p_adc_data)
{
int read_len = 0;
u32 val;
u32 mask;
u32 val_check;
int failed_cnt = 0;
struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
mutex_lock(&adc_priv->mutex);
/*
* After a read is complete the ADC interrupts will be disabled so
* we can assume this section of code is safe from interrupts.
*/
adc_priv->chan_val = -1;
adc_priv->chan_id = channel;
reinit_completion(&adc_priv->completion);
/* Clear any pending interrupt */
regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
IPROC_ADC_INTR_MASK | IPROC_ADC_AUXDATA_RDY_INTR,
((0x0 << channel) << IPROC_ADC_INTR) |
IPROC_ADC_AUXDATA_RDY_INTR);
/* Configure channel for snapshot mode and enable */
val = (BIT(IPROC_ADC_CHANNEL_ROUNDS) |
(IPROC_ADC_CHANNEL_MODE_SNAPSHOT << IPROC_ADC_CHANNEL_MODE) |
(0x1 << IPROC_ADC_CHANNEL_ENABLE));
mask = IPROC_ADC_CHANNEL_ROUNDS_MASK | IPROC_ADC_CHANNEL_MODE_MASK |
IPROC_ADC_CHANNEL_ENABLE_MASK;
regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_REGCTL1 +
IPROC_ADC_CHANNEL_OFFSET * channel),
mask, val);
/* Set the Watermark for a channel */
regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_REGCTL2 +
IPROC_ADC_CHANNEL_OFFSET * channel),
IPROC_ADC_CHANNEL_WATERMARK_MASK,
0x1);
/* Enable water mark interrupt */
regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_INTERRUPT_MASK +
IPROC_ADC_CHANNEL_OFFSET *
channel),
IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK,
IPROC_ADC_WATER_MARK_INTR_ENABLE);
regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val);
/* Enable ADC interrupt for a channel */
val |= (BIT(channel) << IPROC_ADC_INTR);
regmap_write(adc_priv->regmap, IPROC_INTERRUPT_MASK, val);
/*
* There seems to be a very rare issue where writing to this register
* does not take effect. To work around the issue we will try multiple
* writes. In total we will spend about 10*10 = 100 us attempting this.
* Testing has shown that this may loop a few time, but we have never
* hit the full count.
*/
regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
while (val_check != val) {
failed_cnt++;
if (failed_cnt > IPROC_ADC_INTMASK_RETRY_ATTEMPTS)
break;
udelay(10);
regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_MASK,
IPROC_ADC_INTR_MASK,
((0x1 << channel) <<
IPROC_ADC_INTR));
regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
}
if (failed_cnt) {
dev_dbg(&indio_dev->dev,
"IntMask failed (%d times)", failed_cnt);
if (failed_cnt > IPROC_ADC_INTMASK_RETRY_ATTEMPTS) {
dev_err(&indio_dev->dev,
"IntMask set failed. Read will likely fail.");
read_len = -EIO;
goto adc_err;
}
}
regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
if (wait_for_completion_timeout(&adc_priv->completion,
IPROC_ADC_READ_TIMEOUT) > 0) {
/* Only the lower 16 bits are relevant */
*p_adc_data = adc_priv->chan_val & 0xFFFF;
read_len = sizeof(*p_adc_data);
} else {
/*
* We never got the interrupt, something went wrong.
* Perhaps the interrupt may still be coming, we do not want
* that now. Lets disable the ADC interrupt, and clear the
* status to put it back in to normal state.
*/
read_len = -ETIMEDOUT;
goto adc_err;
}
mutex_unlock(&adc_priv->mutex);
return read_len;
adc_err:
regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_MASK,
IPROC_ADC_INTR_MASK,
((0x0 << channel) << IPROC_ADC_INTR));
regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
IPROC_ADC_INTR_MASK,
((0x0 << channel) << IPROC_ADC_INTR));
dev_err(&indio_dev->dev, "Timed out waiting for ADC data!\n");
iproc_adc_reg_dump(indio_dev);
mutex_unlock(&adc_priv->mutex);
return read_len;
}
static int iproc_adc_enable(struct iio_dev *indio_dev)
{
u32 val;
u32 channel_id;
struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
int ret;
/* Set i_amux = 3b'000, select channel 0 */
ret = regmap_update_bits(adc_priv->regmap, IPROC_ANALOG_CONTROL,
IPROC_ADC_CHANNEL_SEL_MASK, 0);
if (ret) {
dev_err(&indio_dev->dev,
"failed to write IPROC_ANALOG_CONTROL %d\n", ret);
return ret;
}
adc_priv->chan_val = -1;
/*
* PWR up LDO, ADC, and Band Gap (0 to enable)
* Also enable ADC controller (set high)
*/
ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
if (ret) {
dev_err(&indio_dev->dev,
"failed to read IPROC_REGCTL2 %d\n", ret);
return ret;
}
val &= ~(IPROC_ADC_PWR_LDO | IPROC_ADC_PWR_ADC | IPROC_ADC_PWR_BG);
ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
if (ret) {
dev_err(&indio_dev->dev,
"failed to write IPROC_REGCTL2 %d\n", ret);
return ret;
}
ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
if (ret) {
dev_err(&indio_dev->dev,
"failed to read IPROC_REGCTL2 %d\n", ret);
return ret;
}
val |= IPROC_ADC_CONTROLLER_EN;
ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
if (ret) {
dev_err(&indio_dev->dev,
"failed to write IPROC_REGCTL2 %d\n", ret);
return ret;
}
for (channel_id = 0; channel_id < indio_dev->num_channels;
channel_id++) {
ret = regmap_write(adc_priv->regmap,
IPROC_ADC_CHANNEL_INTERRUPT_MASK +
IPROC_ADC_CHANNEL_OFFSET * channel_id, 0);
if (ret) {
dev_err(&indio_dev->dev,
"failed to write ADC_CHANNEL_INTERRUPT_MASK %d\n",
ret);
return ret;
}
ret = regmap_write(adc_priv->regmap,
IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
IPROC_ADC_CHANNEL_OFFSET * channel_id, 0);
if (ret) {
dev_err(&indio_dev->dev,
"failed to write ADC_CHANNEL_INTERRUPT_STATUS %d\n",
ret);
return ret;
}
}
return 0;
}
static void iproc_adc_disable(struct iio_dev *indio_dev)
{
u32 val;
int ret;
struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
if (ret) {
dev_err(&indio_dev->dev,
"failed to read IPROC_REGCTL2 %d\n", ret);
return;
}
val &= ~IPROC_ADC_CONTROLLER_EN;
ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
if (ret) {
dev_err(&indio_dev->dev,
"failed to write IPROC_REGCTL2 %d\n", ret);
return;
}
}
static int iproc_adc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long mask)
{
u16 adc_data;
int err;
switch (mask) {
case IIO_CHAN_INFO_RAW:
err = iproc_adc_do_read(indio_dev, chan->channel, &adc_data);
if (err < 0)
return err;
*val = adc_data;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_VOLTAGE:
*val = 1800;
*val2 = 10;
return IIO_VAL_FRACTIONAL_LOG2;
default:
return -EINVAL;
}
default:
return -EINVAL;
}
}
static const struct iio_info iproc_adc_iio_info = {
.read_raw = &iproc_adc_read_raw,
};
#define IPROC_ADC_CHANNEL(_index, _id) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = _index, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.datasheet_name = _id, \
}
static const struct iio_chan_spec iproc_adc_iio_channels[] = {
IPROC_ADC_CHANNEL(0, "adc0"),
IPROC_ADC_CHANNEL(1, "adc1"),
IPROC_ADC_CHANNEL(2, "adc2"),
IPROC_ADC_CHANNEL(3, "adc3"),
IPROC_ADC_CHANNEL(4, "adc4"),
IPROC_ADC_CHANNEL(5, "adc5"),
IPROC_ADC_CHANNEL(6, "adc6"),
IPROC_ADC_CHANNEL(7, "adc7"),
};
static int iproc_adc_probe(struct platform_device *pdev)
{
struct iproc_adc_priv *adc_priv;
struct iio_dev *indio_dev = NULL;
int ret;
indio_dev = devm_iio_device_alloc(&pdev->dev,
sizeof(*adc_priv));
if (!indio_dev) {
dev_err(&pdev->dev, "failed to allocate iio device\n");
return -ENOMEM;
}
adc_priv = iio_priv(indio_dev);
platform_set_drvdata(pdev, indio_dev);
mutex_init(&adc_priv->mutex);
init_completion(&adc_priv->completion);
adc_priv->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
"adc-syscon");
if (IS_ERR(adc_priv->regmap)) {
dev_err(&pdev->dev, "failed to get handle for tsc syscon\n");
ret = PTR_ERR(adc_priv->regmap);
return ret;
}
adc_priv->adc_clk = devm_clk_get(&pdev->dev, "tsc_clk");
if (IS_ERR(adc_priv->adc_clk)) {
dev_err(&pdev->dev,
"failed getting clock tsc_clk\n");
ret = PTR_ERR(adc_priv->adc_clk);
return ret;
}
adc_priv->irqno = platform_get_irq(pdev, 0);
if (adc_priv->irqno <= 0)
return -ENODEV;
ret = regmap_update_bits(adc_priv->regmap, IPROC_REGCTL2,
IPROC_ADC_AUXIN_SCAN_ENA, 0);
if (ret) {
dev_err(&pdev->dev, "failed to write IPROC_REGCTL2 %d\n", ret);
return ret;
}
ret = devm_request_threaded_irq(&pdev->dev, adc_priv->irqno,
iproc_adc_interrupt_handler,
iproc_adc_interrupt_thread,
IRQF_SHARED, "iproc-adc", indio_dev);
if (ret) {
dev_err(&pdev->dev, "request_irq error %d\n", ret);
return ret;
}
ret = clk_prepare_enable(adc_priv->adc_clk);
if (ret) {
dev_err(&pdev->dev,
"clk_prepare_enable failed %d\n", ret);
return ret;
}
ret = iproc_adc_enable(indio_dev);
if (ret) {
dev_err(&pdev->dev, "failed to enable adc %d\n", ret);
goto err_adc_enable;
}
indio_dev->name = "iproc-static-adc";
indio_dev->info = &iproc_adc_iio_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = iproc_adc_iio_channels;
indio_dev->num_channels = ARRAY_SIZE(iproc_adc_iio_channels);
ret = iio_device_register(indio_dev);
if (ret) {
dev_err(&pdev->dev, "iio_device_register failed:err %d\n", ret);
goto err_clk;
}
return 0;
err_clk:
iproc_adc_disable(indio_dev);
err_adc_enable:
clk_disable_unprepare(adc_priv->adc_clk);
return ret;
}
static int iproc_adc_remove(struct platform_device *pdev)
{
struct iio_dev *indio_dev = platform_get_drvdata(pdev);
struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
iproc_adc_disable(indio_dev);
clk_disable_unprepare(adc_priv->adc_clk);
return 0;
}
static const struct of_device_id iproc_adc_of_match[] = {
{.compatible = "brcm,iproc-static-adc", },
{ },
};
MODULE_DEVICE_TABLE(of, iproc_adc_of_match);
static struct platform_driver iproc_adc_driver = {
.probe = iproc_adc_probe,
.remove = iproc_adc_remove,
.driver = {
.name = "iproc-static-adc",
.of_match_table = iproc_adc_of_match,
},
};
module_platform_driver(iproc_adc_driver);
MODULE_DESCRIPTION("Broadcom iProc ADC controller driver");
MODULE_AUTHOR("Raveendra Padasalagi <raveendra.padasalagi@broadcom.com>");
MODULE_LICENSE("GPL v2");