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iio: adc: meson-saradc: switch from polling to interrupt mode

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Switch from polling to interrupt mode.

Successfully tested on a S905GXBB-based Odroid C2.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Heiner Kallweit 2017-02-15 20:31:45 +01:00 committed by Jonathan Cameron
parent 74e2419b00
commit 3af109131b
2 changed files with 53 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Documentation/devicetree/bindings/iio/adc/amlogic,meson-saradc.txt
View File

@ -7,6 +7,7 @@ Required properties:
- "amlogic,meson-gxm-saradc" for GXM
along with the generic "amlogic,meson-saradc"
- reg: the physical base address and length of the registers
- interrupts: the interrupt indicating end of sampling
- clocks: phandle and clock identifier (see clock-names)
- clock-names: mandatory clocks:
- "clkin" for the reference clock (typically XTAL)
@ -23,6 +24,7 @@ Example:
compatible = "amlogic,meson-gxl-saradc", "amlogic,meson-saradc";
#io-channel-cells = <1>;
reg = <0x0 0x8680 0x0 0x34>;
interrupts = <GIC_SPI 73 IRQ_TYPE_EDGE_RISING>;
clocks = <&xtal>,
<&clkc CLKID_SAR_ADC>,
<&clkc CLKID_SANA>,

56
drivers/iio/adc/meson_saradc.c
View File

@ -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) {
@ -378,6 +382,12 @@ 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);
@ -391,6 +401,9 @@ 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 +656,7 @@ 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 +681,9 @@ 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 +745,25 @@ 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 +806,7 @@ 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 +815,7 @@ 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 +834,15 @@ 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))