Hi Naveen, On Thursday 02 of May 2013 11:01:03 Naveen Krishna Chatradhi wrote: > From: Naveen Krishna Chatradhi <ch.naveen@xxxxxxxxxxx> > > This patch does the following > 1. use wait_for_completion_timeout instead of > wait_for_completion_interruptible_timeout > 2. Reset software if a timeout happens. > 3. Also reduce the timeout to 100milli secs I wonder what this patch is trying to fix. In what conditions can an ADC conversion time out? Sorry if it was already explained in discussion. Still, I think that commit message of a patch should explain why it is needed. Best regards, Tomasz > Note: submitted for review at > https://patchwork.kernel.org/patch/2279591/ > > Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@xxxxxxxxxxx> > Cc: Doug Anderson <dianders@xxxxxxxxxxxx> > Cc: Lars-Peter Clausen <lars@xxxxxxxxxx> > --- > Changes since v1: > As per discussion at > http://marc.info/?l=linux-kernel&m=136517637228869&w=3 > > This patch does the following > 1. use wait_for_completion_timeout instead of > wait_for_completion_interruptible_timeout > 2. Reset software if a timeout happens. > 3. Also reduce the timeout to 100milli secs > > drivers/iio/adc/exynos_adc.c | 73 > ++++++++++++++++++++++++------------------ 1 file changed, 42 > insertions(+), 31 deletions(-) > > diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c > index 9f3a8ef..a400bb8 100644 > --- a/drivers/iio/adc/exynos_adc.c > +++ b/drivers/iio/adc/exynos_adc.c > @@ -81,7 +81,7 @@ 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; > @@ -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, > @@ -120,6 +149,7 @@ 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; > @@ -144,16 +174,21 @@ 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; > > - 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 { > + *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 +260,6 @@ 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; -- 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
