Switch from polling to interrupt mode.
Successfully tested on a S905GXBB-based Odroid C2.
Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
---
drivers/iio/adc/meson_saradc.c | 46 +++++++++++++++++++++++++++++++++++++-----
1 file changed, 41 insertions(+), 5 deletions(-)
diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
index 89def603..dbd56bcc 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 = {
@@ -274,11 +278,11 @@ 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, sum = 0, count = 0;
- ret = meson_sar_adc_wait_busy_clear(indio_dev);
- if (ret)
- return ret;
+ if(!wait_for_completion_timeout(&priv->done,
+ msecs_to_jiffies(MESON_SAR_ADC_TIMEOUT)))
+ return -ETIMEDOUT;
while (meson_sar_adc_get_fifo_count(indio_dev) > 0 &&
count < MESON_SAR_ADC_MAX_FIFO_SIZE) {
@@ -456,6 +460,7 @@ static int meson_sar_adc_get_sample(struct iio_dev *indio_dev,
enum meson_sar_adc_num_samples avg_samples,
int *val)
{
+ struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
int ret;
ret = meson_sar_adc_lock(indio_dev);
@@ -465,6 +470,11 @@ static int meson_sar_adc_get_sample(struct iio_dev *indio_dev,
/* clear the FIFO to make sure we're not reading old values */
meson_sar_adc_clear_fifo(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);
+
meson_sar_adc_set_averaging(indio_dev, chan, avg_mode, avg_samples);
meson_sar_adc_enable_channel(indio_dev, chan);
@@ -473,6 +483,9 @@ static int meson_sar_adc_get_sample(struct iio_dev *indio_dev,
ret = meson_sar_adc_read_raw_sample(indio_dev, chan, val);
meson_sar_adc_stop_sample_engine(indio_dev);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
+ MESON_SAR_ADC_REG0_FIFO_IRQ_EN, 0);
+
meson_sar_adc_unlock(indio_dev);
if (ret) {
@@ -577,6 +590,9 @@ static int meson_sar_adc_init(struct iio_dev *indio_dev)
*/
meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_CH7_INPUT);
+ 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);
/*
* leave sampling delay and the input clocks as configured by BL30 to
* make sure BL30 gets the values it expects when reading the
@@ -728,6 +744,16 @@ 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);
+
+ 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 +796,7 @@ 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 +805,7 @@ 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 +824,15 @@ 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, 0,
+ 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))
--
2.11.1
--
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