On 3 April 2013 20:59, Naveen Krishna Chatradhi <naveenkrishna.ch@xxxxxxxxx> wrote: > 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 Apologize for sending the patch with local changes. > 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 > -- Shine bright, (: Nav :) -- 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
