From: Naveen Krishna Chatradhi <ch.naveen@xxxxxxxxxxx> This patch does the following 1. Handle the return values of wait_for_completion_interruptible_timeout 2. Reset software if a timeout happes. Note: submitted for review at https://patchwork.kernel.org/patch/2279591/ BUG=None TEST=None Change-Id: I9858d19ba40353e72ae38a6cbf7e6f400e6d3c22 Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@xxxxxxxxxxx> Cc: Doug Anderson <dianders@xxxxxxxxxxxx> Cc: Lars-Peter Clausen <lars@xxxxxxxxxx> --- As per the comments from Doug at http://marc.info/?l=linux-kernel&m=136500878406955&w=3 Changes since v1: 1. Remove the spin lock implememtation and the INIT_COMPLETION 2. Rearrange the code and reset the ADC in cases of timeout. drivers/iio/adc/exynos_adc.c | 73 ++++++++++++++++++++++++++------------------ 1 file changed, 43 insertions(+), 30 deletions(-) diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c index 5ab0dfd..a6c4df5 100644 --- a/drivers/iio/adc/exynos_adc.c +++ b/drivers/iio/adc/exynos_adc.c @@ -111,6 +111,35 @@ 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; + int delay; + + if (info->version == ADC_V2) { + con1 = ADC_V2_CON1_SOFT_RESET; + writel(con1, ADC_V2_CON1(info->regs)); + + /* ADC H/W requires 25PCLKs before other register access */ + delay = DIV_ROUND_UP(25 * 1000000, clk_get_rate(info->clk)); + udelay(delay); + + 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, @@ -118,8 +147,9 @@ static int exynos_read_raw(struct iio_dev *indio_dev, long mask) { struct exynos_adc *info = iio_priv(indio_dev); - unsigned long timeout; + long timeout; u32 con1, con2; + int ret; if (mask != IIO_CHAN_INFO_RAW) return -EINVAL; @@ -146,14 +176,21 @@ static int exynos_read_raw(struct iio_dev *indio_dev, timeout = wait_for_completion_interruptible_timeout (&info->completion, EXYNOS_ADC_TIMEOUT); - *val = info->value; - mutex_unlock(&indio_dev->mlock); + if (timeout == 0) { + dev_warn(&indio_dev->dev, "Conversion timed out reseting\n"); + exynos_adc_hw_init(info); + ret = -ETIMEDOUT; + } else if (timeout < 0) { + ret = timeout; + } else { + *val = info->value; + ret = IIO_VAL_INT; + } - if (timeout == 0) - return -ETIMEDOUT; + mutex_unlock(&indio_dev->mlock); - return IIO_VAL_INT; + return ret; } static irqreturn_t exynos_adc_isr(int irq, void *dev_id) @@ -225,30 +262,6 @@ 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; -- 1.7.12.4 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
