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path: root/drivers/iio/adc/meson_saradc.c
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Diffstat (limited to 'drivers/iio/adc/meson_saradc.c')
-rw-r--r--drivers/iio/adc/meson_saradc.c90
1 files changed, 67 insertions, 23 deletions
diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
index 89def6034f40..cde9ca7a01b8 100644
--- a/drivers/iio/adc/meson_saradc.c
+++ b/drivers/iio/adc/meson_saradc.c
@@ -18,7 +18,9 @@
#include <linux/io.h>
#include <linux/iio/iio.h>
#include <linux/module.h>
+#include <linux/interrupt.h>
#include <linux/of.h>
+#include <linux/of_irq.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
@@ -163,6 +165,7 @@
#define MESON_SAR_ADC_REG13_12BIT_CALIBRATION_MASK GENMASK(13, 8)
#define MESON_SAR_ADC_MAX_FIFO_SIZE 32
+#define MESON_SAR_ADC_TIMEOUT 100 /* ms */
#define MESON_SAR_ADC_CHAN(_chan) { \
.type = IIO_VOLTAGE, \
@@ -229,6 +232,7 @@ struct meson_sar_adc_priv {
struct clk_gate clk_gate;
struct clk *adc_div_clk;
struct clk_divider clk_div;
+ struct completion done;
};
static const struct regmap_config meson_sar_adc_regmap_config = {
@@ -274,33 +278,31 @@ static int meson_sar_adc_read_raw_sample(struct iio_dev *indio_dev,
int *val)
{
struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
- int ret, regval, fifo_chan, fifo_val, sum = 0, count = 0;
+ int regval, fifo_chan, fifo_val, count;
- ret = meson_sar_adc_wait_busy_clear(indio_dev);
- if (ret)
- return ret;
-
- while (meson_sar_adc_get_fifo_count(indio_dev) > 0 &&
- count < MESON_SAR_ADC_MAX_FIFO_SIZE) {
- regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &regval);
-
- fifo_chan = FIELD_GET(MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK,
- regval);
- if (fifo_chan != chan->channel)
- continue;
-
- fifo_val = FIELD_GET(MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK,
- regval);
- fifo_val &= (BIT(priv->data->resolution) - 1);
+ if(!wait_for_completion_timeout(&priv->done,
+ msecs_to_jiffies(MESON_SAR_ADC_TIMEOUT)))
+ return -ETIMEDOUT;
- sum += fifo_val;
- count++;
+ count = meson_sar_adc_get_fifo_count(indio_dev);
+ if (count != 1) {
+ dev_err(&indio_dev->dev,
+ "ADC FIFO has %d element(s) instead of one\n", count);
+ return -EINVAL;
}
- if (!count)
- return -ENOENT;
+ regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &regval);
+ fifo_chan = FIELD_GET(MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK, regval);
+ if (fifo_chan != chan->channel) {
+ dev_err(&indio_dev->dev,
+ "ADC FIFO entry belongs to channel %d instead of %d\n",
+ fifo_chan, chan->channel);
+ return -EINVAL;
+ }
- *val = sum / count;
+ fifo_val = FIELD_GET(MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK, regval);
+ fifo_val &= GENMASK(priv->data->resolution - 1, 0);
+ *val = fifo_val;
return 0;
}
@@ -378,6 +380,12 @@ static void meson_sar_adc_start_sample_engine(struct iio_dev *indio_dev)
{
struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
+ reinit_completion(&priv->done);
+
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
+ MESON_SAR_ADC_REG0_FIFO_IRQ_EN,
+ MESON_SAR_ADC_REG0_FIFO_IRQ_EN);
+
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE,
MESON_SAR_ADC_REG0_SAMPLE_ENGINE_ENABLE);
@@ -392,6 +400,9 @@ static void meson_sar_adc_stop_sample_engine(struct iio_dev *indio_dev)
struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
+ MESON_SAR_ADC_REG0_FIFO_IRQ_EN, 0);
+
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
MESON_SAR_ADC_REG0_SAMPLING_STOP,
MESON_SAR_ADC_REG0_SAMPLING_STOP);
@@ -643,6 +654,7 @@ static int meson_sar_adc_hw_enable(struct iio_dev *indio_dev)
{
struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
int ret;
+ u32 regval;
ret = meson_sar_adc_lock(indio_dev);
if (ret)
@@ -667,6 +679,9 @@ static int meson_sar_adc_hw_enable(struct iio_dev *indio_dev)
goto err_sana_clk;
}
+ regval = FIELD_PREP(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, 1);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
+ MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
MESON_SAR_ADC_REG11_BANDGAP_EN,
MESON_SAR_ADC_REG11_BANDGAP_EN);
@@ -728,6 +743,25 @@ static int meson_sar_adc_hw_disable(struct iio_dev *indio_dev)
return 0;
}
+static irqreturn_t meson_sar_adc_irq(int irq, void *data)
+{
+ struct iio_dev *indio_dev = data;
+ struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
+ unsigned int cnt, threshold;
+ u32 regval;
+
+ regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
+ cnt = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
+ threshold = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
+
+ if (cnt < threshold)
+ return IRQ_NONE;
+
+ complete(&priv->done);
+
+ return IRQ_HANDLED;
+}
+
static const struct iio_info meson_sar_adc_iio_info = {
.read_raw = meson_sar_adc_iio_info_read_raw,
.driver_module = THIS_MODULE,
@@ -770,7 +804,7 @@ static int meson_sar_adc_probe(struct platform_device *pdev)
struct resource *res;
void __iomem *base;
const struct of_device_id *match;
- int ret;
+ int irq, ret;
indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
if (!indio_dev) {
@@ -779,6 +813,7 @@ static int meson_sar_adc_probe(struct platform_device *pdev)
}
priv = iio_priv(indio_dev);
+ init_completion(&priv->done);
match = of_match_device(meson_sar_adc_of_match, &pdev->dev);
priv->data = match->data;
@@ -797,6 +832,15 @@ static int meson_sar_adc_probe(struct platform_device *pdev)
if (IS_ERR(base))
return PTR_ERR(base);
+ irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
+ if (!irq)
+ return -EINVAL;
+
+ ret = devm_request_irq(&pdev->dev, irq, meson_sar_adc_irq, IRQF_SHARED,
+ dev_name(&pdev->dev), indio_dev);
+ if (ret)
+ return ret;
+
priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
&meson_sar_adc_regmap_config);
if (IS_ERR(priv->regmap))