From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754148Ab3KEJnz (ORCPT ); Tue, 5 Nov 2013 04:43:55 -0500 Received: from mailout3.samsung.com ([203.254.224.33]:59708 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752072Ab3KEJnv (ORCPT ); Tue, 5 Nov 2013 04:43:51 -0500 X-AuditID: cbfee68f-b7f836d000001b39-8f-5278bdd509ec From: Naveen Krishna Chatradhi To: linux-iio@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org, dianders@chromium.org, gregkh@linuxfoundation.org, naveenkrishna.ch@gmail.com, lars@metafoo.de, grundler@chromium.org, cpgs@samsung.com Subject: [PATCH v6] iio: exynos_adc: use wait_for_completion_timeout instead of interruptible Date: Tue, 05 Nov 2013 15:15:30 +0530 Message-id: <1383644730-23228-1-git-send-email-ch.naveen@samsung.com> X-Mailer: git-send-email 1.7.10.4 In-reply-to: <1381479821-17276-1-git-send-email-ch.naveen@samsung.com> References: <1381479821-17276-1-git-send-email-ch.naveen@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmpkkeLIzCtJLcpLzFFi42JZI2JSpXttb0WQwfEOZouXhzQtzi47yGbR vHg9m8WrIz+YLJZMns9qMe/IOxaLy7vmsFnMOL+PyWLRtv/MDpwesxsusnjsnHWX3WP/3DXs HkveHGL16NuyitHj8ya5ALYoLpuU1JzMstQifbsEroz9p46xFxxTrfh2fyZ7A+MnuS5GTg4J AROJtrfrWCBsMYkL99azdTFycQgJLGWUWPhzBWsXIwdY0bl5NiA1QgLTGSWm7nCDqOlhkvj/ 6BQ7SIJNwEzi4KLV7CD1IgKyEjO79UBqmAUuMEo0fVvKClIjLBAv8f3eFDYQm0VAVWLW9L3M IPW8Aq4S0w4zQ9ygKNH9bAIbSJhTwE2i64Q4xFpXiZ1r94CdJiGwiV3izKebrBBjBCS+TT7E AnGmrMSmA1BjJCUOrrjBMoFReAEjwypG0dSC5ILipPQiY73ixNzi0rx0veT83E2MwOA//e9Z /w7GuwesDzEmA42byCwlmpwPjJ68knhDYzMjC1MTU2Mjc0sz0oSVxHnvP0wKEhJITyxJzU5N LUgtii8qzUktPsTIxMEp1cDoe/UH95wFTAz/Pa+mNvk3Ov9yfBj2yKF6Qk7lzGnZPr/djZJK NYtO7Kq1u+aq8WDmmdKQT50Hr173l5Yve9CgrdnSEfxE1HJJcdwPTzWhzMCo3cqJoseSZK/o uQUaSkeeLxM2XsX+nUNOU8Wq8lXKj7UFh1ouKBgzrbCd0qzUuXPJg/P9B5VYijMSDbWYi4oT AUuPxF2UAgAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrHIsWRmVeSWpSXmKPExsVy+t9jQd2reyuCDK5vNrd4eUjT4uyyg2wW zYvXs1m8OvKDyWLJ5PmsFvOOvGOxuLxrDpvFjPP7mCwWbfvP7MDpMbvhIovHzll32T32z13D 7rHkzSFWj74tqxg9Pm+SC2CLamC0yUhNTEktUkjNS85PycxLt1XyDo53jjc1MzDUNbS0MFdS yEvMTbVVcvEJ0HXLzAG6SkmhLDGnFCgUkFhcrKRvh2lCaIibrgVMY4Sub0gQXI+RARpIWMOY sf/UMfaCY6oV3+7PZG9g/CTXxcjBISFgInFunk0XIyeQKSZx4d56NhBbSGA6o8TUHW5djFxA dg+TxP9Hp9hBEmwCZhIHF61mB+kVEZCVmNmtB1LDLHCBUaLp21JWkBphgXiJ7/emgA1iEVCV mDV9LzNIPa+Aq8S0w8wQuxQlup9NYAMJcwq4SXSdEIdY6yqxc+0etgmMvAsYGVYxiqYWJBcU J6XnGukVJ+YWl+al6yXn525iBMfWM+kdjKsaLA4xCnAwKvHwXgytCBJiTSwrrsw9xCjBwawk wsuxGyjEm5JYWZValB9fVJqTWnyIMRnoponMUqLJ+cC4zyuJNzQ2MTc1NrU0sTAxsyRNWEmc 92CrdaCQQHpiSWp2ampBahHMFiYOTqkGxolTl7lzacbumunP+HzfrcvzuqwWB7o32nqs4n5z scR/zdN9LbyNaRUvk7+4XBSdoCX7W9GyriPjjH7NsntT5W68fOefwsx2mHGxvmlZoYXL2Uyt +2F+Csb7TA6VswrVvqjakveue2eR35pbXjV2CtuF/uqYx2no2n2KXxWy64Vo0taCC9zPlFiK MxINtZiLihMBlX5qHfECAAA= DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 1. The irq routine is so simple (just one register read) shouldn't be long Hence, reduce the timeout to 100milli secs, 2. With 100ms of wait time, interruptible is very much unnecessary. Hence, use wait_for_completion_timeout instead of wait_for_completion_interruptible_timeout 3. Reset software if a timeout happens. 4. Add reinit_completion() before the wait_for_completion_timeout in raw_read() Note: submitted for review at https://patchwork.kernel.org/patch/2279591/ Signed-off-by: Naveen Krishna Chatradhi Cc: Doug Anderson Cc: Lars-Peter Clausen Reviewed-on: https://chromium-review.googlesource.com/172724 Reviewed-by: Doug Anderson --- Changes since v1: As per discussion at http://marc.info/?l=linux-kernel&m=136517637228869&w=3 Changes since v2: None. Rebased and reposting. Changes since v3: 1. commit message change and 2. removed an unncessary assignment Changes since v4: Moved INIT_COMPLETION call to the starting of the function Changes since v5: INIT_COMPLETION was replaced by reinit_completion ("tree-wide: use reinit_completion instead of INIT_COMPLETION"). Use it to avoid the following build error: undefined identifier 'INIT_COMPLETION' drivers/iio/adc/exynos_adc.c | 69 ++++++++++++++++++++++++-------------------- 1 file changed, 38 insertions(+), 31 deletions(-) diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c index 0f2ca60..a675751 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 +111,30 @@ 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, @@ -120,11 +144,13 @@ 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) { @@ -144,16 +170,21 @@ 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) @@ -225,30 +256,6 @@ 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