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path: root/drivers/iio/adc/exynos_adc.c
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Diffstat (limited to 'drivers/iio/adc/exynos_adc.c')
-rw-r--r--drivers/iio/adc/exynos_adc.c131
1 files changed, 71 insertions, 60 deletions
diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c
index affa93f51789..010578f1d762 100644
--- a/drivers/iio/adc/exynos_adc.c
+++ b/drivers/iio/adc/exynos_adc.c
@@ -82,7 +82,7 @@ enum adc_version {
#define ADC_CON_EN_START (1u << 0)
#define ADC_DATX_MASK 0xFFF
-#define EXYNOS_ADC_TIMEOUT (msecs_to_jiffies(1000))
+#define EXYNOS_ADC_TIMEOUT (msecs_to_jiffies(100))
struct exynos_adc {
void __iomem *regs;
@@ -112,6 +112,30 @@ static inline unsigned int exynos_adc_get_version(struct platform_device *pdev)
return (unsigned int)match->data;
}
+static void exynos_adc_hw_init(struct exynos_adc *info)
+{
+ u32 con1, con2;
+
+ if (info->version == ADC_V2) {
+ con1 = ADC_V2_CON1_SOFT_RESET;
+ writel(con1, ADC_V2_CON1(info->regs));
+
+ con2 = ADC_V2_CON2_OSEL | ADC_V2_CON2_ESEL |
+ ADC_V2_CON2_HIGHF | ADC_V2_CON2_C_TIME(0);
+ writel(con2, ADC_V2_CON2(info->regs));
+
+ /* Enable interrupts */
+ writel(1, ADC_V2_INT_EN(info->regs));
+ } else {
+ /* set default prescaler values and Enable prescaler */
+ con1 = ADC_V1_CON_PRSCLV(49) | ADC_V1_CON_PRSCEN;
+
+ /* Enable 12-bit ADC resolution */
+ con1 |= ADC_V1_CON_RES;
+ writel(con1, ADC_V1_CON(info->regs));
+ }
+}
+
static int exynos_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
@@ -121,11 +145,13 @@ static int exynos_read_raw(struct iio_dev *indio_dev,
struct exynos_adc *info = iio_priv(indio_dev);
unsigned long timeout;
u32 con1, con2;
+ int ret;
if (mask != IIO_CHAN_INFO_RAW)
return -EINVAL;
mutex_lock(&indio_dev->mlock);
+ reinit_completion(&info->completion);
/* Select the channel to be used and Trigger conversion */
if (info->version == ADC_V2) {
@@ -145,16 +171,21 @@ static int exynos_read_raw(struct iio_dev *indio_dev,
ADC_V1_CON(info->regs));
}
- timeout = wait_for_completion_interruptible_timeout
+ timeout = wait_for_completion_timeout
(&info->completion, EXYNOS_ADC_TIMEOUT);
- *val = info->value;
+ if (timeout == 0) {
+ dev_warn(&indio_dev->dev, "Conversion timed out! Resetting\n");
+ exynos_adc_hw_init(info);
+ ret = -ETIMEDOUT;
+ } else {
+ *val = info->value;
+ *val2 = 0;
+ ret = IIO_VAL_INT;
+ }
mutex_unlock(&indio_dev->mlock);
- if (timeout == 0)
- return -ETIMEDOUT;
-
- return IIO_VAL_INT;
+ return ret;
}
static irqreturn_t exynos_adc_isr(int irq, void *dev_id)
@@ -226,30 +257,6 @@ static int exynos_adc_remove_devices(struct device *dev, void *c)
return 0;
}
-static void exynos_adc_hw_init(struct exynos_adc *info)
-{
- u32 con1, con2;
-
- if (info->version == ADC_V2) {
- con1 = ADC_V2_CON1_SOFT_RESET;
- writel(con1, ADC_V2_CON1(info->regs));
-
- con2 = ADC_V2_CON2_OSEL | ADC_V2_CON2_ESEL |
- ADC_V2_CON2_HIGHF | ADC_V2_CON2_C_TIME(0);
- writel(con2, ADC_V2_CON2(info->regs));
-
- /* Enable interrupts */
- writel(1, ADC_V2_INT_EN(info->regs));
- } else {
- /* set default prescaler values and Enable prescaler */
- con1 = ADC_V1_CON_PRSCLV(49) | ADC_V1_CON_PRSCEN;
-
- /* Enable 12-bit ADC resolution */
- con1 |= ADC_V1_CON_RES;
- writel(con1, ADC_V1_CON(info->regs));
- }
-}
-
static int exynos_adc_probe(struct platform_device *pdev)
{
struct exynos_adc *info = NULL;
@@ -290,32 +297,30 @@ static int exynos_adc_probe(struct platform_device *pdev)
init_completion(&info->completion);
- ret = request_irq(info->irq, exynos_adc_isr,
- 0, dev_name(&pdev->dev), info);
- if (ret < 0) {
- dev_err(&pdev->dev, "failed requesting irq, irq = %d\n",
- info->irq);
- return ret;
- }
-
- writel(1, info->enable_reg);
-
info->clk = devm_clk_get(&pdev->dev, "adc");
if (IS_ERR(info->clk)) {
dev_err(&pdev->dev, "failed getting clock, err = %ld\n",
PTR_ERR(info->clk));
- ret = PTR_ERR(info->clk);
- goto err_irq;
+ return PTR_ERR(info->clk);
}
info->vdd = devm_regulator_get(&pdev->dev, "vdd");
if (IS_ERR(info->vdd)) {
dev_err(&pdev->dev, "failed getting regulator, err = %ld\n",
PTR_ERR(info->vdd));
- ret = PTR_ERR(info->vdd);
- goto err_irq;
+ return PTR_ERR(info->vdd);
}
+ ret = regulator_enable(info->vdd);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(info->clk);
+ if (ret)
+ goto err_disable_reg;
+
+ writel(1, info->enable_reg);
+
info->version = exynos_adc_get_version(pdev);
platform_set_drvdata(pdev, indio_dev);
@@ -332,16 +337,18 @@ static int exynos_adc_probe(struct platform_device *pdev)
else
indio_dev->num_channels = MAX_ADC_V2_CHANNELS;
+ ret = request_irq(info->irq, exynos_adc_isr,
+ 0, dev_name(&pdev->dev), info);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed requesting irq, irq = %d\n",
+ info->irq);
+ goto err_disable_clk;
+ }
+
ret = iio_device_register(indio_dev);
if (ret)
goto err_irq;
- ret = regulator_enable(info->vdd);
- if (ret)
- goto err_iio_dev;
-
- clk_prepare_enable(info->clk);
-
exynos_adc_hw_init(info);
ret = of_platform_populate(np, exynos_adc_match, NULL, &indio_dev->dev);
@@ -355,12 +362,14 @@ static int exynos_adc_probe(struct platform_device *pdev)
err_of_populate:
device_for_each_child(&indio_dev->dev, NULL,
exynos_adc_remove_devices);
- regulator_disable(info->vdd);
- clk_disable_unprepare(info->clk);
-err_iio_dev:
iio_device_unregister(indio_dev);
err_irq:
free_irq(info->irq, info);
+err_disable_clk:
+ writel(0, info->enable_reg);
+ clk_disable_unprepare(info->clk);
+err_disable_reg:
+ regulator_disable(info->vdd);
return ret;
}
@@ -371,11 +380,11 @@ static int exynos_adc_remove(struct platform_device *pdev)
device_for_each_child(&indio_dev->dev, NULL,
exynos_adc_remove_devices);
- regulator_disable(info->vdd);
- clk_disable_unprepare(info->clk);
- writel(0, info->enable_reg);
iio_device_unregister(indio_dev);
free_irq(info->irq, info);
+ writel(0, info->enable_reg);
+ clk_disable_unprepare(info->clk);
+ regulator_disable(info->vdd);
return 0;
}
@@ -397,8 +406,8 @@ static int exynos_adc_suspend(struct device *dev)
writel(con, ADC_V1_CON(info->regs));
}
- clk_disable_unprepare(info->clk);
writel(0, info->enable_reg);
+ clk_disable_unprepare(info->clk);
regulator_disable(info->vdd);
return 0;
@@ -414,9 +423,11 @@ static int exynos_adc_resume(struct device *dev)
if (ret)
return ret;
- writel(1, info->enable_reg);
- clk_prepare_enable(info->clk);
+ ret = clk_prepare_enable(info->clk);
+ if (ret)
+ return ret;
+ writel(1, info->enable_reg);
exynos_adc_hw_init(info);
return 0;