From patchwork Sun Jan 28 15:05:29 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 13534492 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B8F0D249E0 for ; Sun, 28 Jan 2024 15:06:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706454391; cv=none; b=tCXlvoMP5bOu7rwuolModDks7GizwU5Az60fDuJaQaUK3sNCAaDTPgCGfN2KNZBYVm4VAXsNr1uMRf+qidK7Y7JeFLmaU/dsVlyoUBFPXHGToldebQnwjqMvz97r9u7L8oNAntfaaFZDC/WI+8NR3/5YPvJeXD3qCoTlopTpJGE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706454391; c=relaxed/simple; bh=6CPqUyum2zElftouZAXwLsMpESWjiO9AypwSaSdSw90=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ajdl5oUqr2/jyDL46eJTXMaMqz44ETfMKp4mbhY9FYmG1E6RVV+RybGKgbnk9jBRg2FJUuZpdy2F7uABrVJy9Zb6Dv8uyUV8EQFWe0j75weHQYByzgJjHTDVm7kAdvRvVzjZSMOZoELxIrhbyJ0EiPc6pPA5icrw51MklKc+E0s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RwjvBeIC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="RwjvBeIC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4827C43399; Sun, 28 Jan 2024 15:06:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706454391; bh=6CPqUyum2zElftouZAXwLsMpESWjiO9AypwSaSdSw90=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RwjvBeICHpDXb53L/YS6lMXvdUzW6g1dR/zHKxAloMoUndXK0QgGJgAbzCtiOkkSu UsoKCqpNquVN5M1lm1zxgn+HGyYLrV1qcGyEjmRMMwmHp+JKtX99y+yKpgwQdkRUu2 uZxAEgtUn7UdHyZyXezWVLvRe+uVFd8Sh8/B+gx+W59tL5whuoX5uGqlcLoiDEJt91 OfUvP7yo77JraSB16wvdOFKWKWLIIQnLoJbpFBMha/Z3Ux31OwKJytpUSLJeuLpaFf 9VCNe99Mbut+jJGp8mfB4qdUCy4gnACE4I3dX/YY+SiI6FgHk1x/uMBfuOBegQkdN6 XxgIfZFpHGWSQ== From: Jonathan Cameron To: linux-iio@vger.kernel.org Cc: David Lechner , Peter Zijlstra , Jonathan Cameron Subject: [PATCH 02/10] iio: dummy: Use automatic lock and direct mode cleanup. Date: Sun, 28 Jan 2024 15:05:29 +0000 Message-ID: <20240128150537.44592-3-jic23@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240128150537.44592-1-jic23@kernel.org> References: <20240128150537.44592-1-jic23@kernel.org> Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Jonathan Cameron Given we now have iio_device_claim_direct_scoped() to perform automatic releasing of direct mode at exit from the scope that follows it, this can be used in conjunction with guard(mutex) etc remove a lot of special case handling. Note that in this particular example code, there is no real reason you can't read channels via sysfs at the same time as filling the software buffer. To make it look more like a real driver constrain raw and processed channel reads from occurring whilst the buffer is in use. Signed-off-by: Jonathan Cameron Reviewed-by: David Lechner --- Since RFC: - Dropped a stale comment about a local variable that existed in an earlier version of this patch before the new scoped_guard_cond() infrastructure was added. - Use unreachable() to convince the compiler we can't get to code at end of the pattern. iio_device_claim_direct_scoped(return -EBUSY, iio_dev) { return 0; } unreacahable(); --- drivers/iio/dummy/iio_simple_dummy.c | 182 +++++++++++++-------------- 1 file changed, 88 insertions(+), 94 deletions(-) diff --git a/drivers/iio/dummy/iio_simple_dummy.c b/drivers/iio/dummy/iio_simple_dummy.c index c24f609c2ade..d6ef556698fb 100644 --- a/drivers/iio/dummy/iio_simple_dummy.c +++ b/drivers/iio/dummy/iio_simple_dummy.c @@ -283,65 +283,63 @@ static int iio_dummy_read_raw(struct iio_dev *indio_dev, long mask) { struct iio_dummy_state *st = iio_priv(indio_dev); - int ret = -EINVAL; - mutex_lock(&st->lock); switch (mask) { case IIO_CHAN_INFO_RAW: /* magic value - channel value read */ - switch (chan->type) { - case IIO_VOLTAGE: - if (chan->output) { - /* Set integer part to cached value */ - *val = st->dac_val; - ret = IIO_VAL_INT; - } else if (chan->differential) { - if (chan->channel == 1) - *val = st->differential_adc_val[0]; - else - *val = st->differential_adc_val[1]; - ret = IIO_VAL_INT; - } else { - *val = st->single_ended_adc_val; - ret = IIO_VAL_INT; + iio_device_claim_direct_scoped(return -EBUSY, indio_dev) { + guard(mutex)(&st->lock); + switch (chan->type) { + case IIO_VOLTAGE: + if (chan->output) { + /* Set integer part to cached value */ + *val = st->dac_val; + return IIO_VAL_INT; + } else if (chan->differential) { + if (chan->channel == 1) + *val = st->differential_adc_val[0]; + else + *val = st->differential_adc_val[1]; + return IIO_VAL_INT; + } else { + *val = st->single_ended_adc_val; + return IIO_VAL_INT; + } + + case IIO_ACCEL: + *val = st->accel_val; + return IIO_VAL_INT; + default: + return -EINVAL; } - break; - case IIO_ACCEL: - *val = st->accel_val; - ret = IIO_VAL_INT; - break; - default: - break; } - break; + unreachable(); case IIO_CHAN_INFO_PROCESSED: - switch (chan->type) { - case IIO_STEPS: - *val = st->steps; - ret = IIO_VAL_INT; - break; - case IIO_ACTIVITY: - switch (chan->channel2) { - case IIO_MOD_RUNNING: - *val = st->activity_running; - ret = IIO_VAL_INT; - break; - case IIO_MOD_WALKING: - *val = st->activity_walking; - ret = IIO_VAL_INT; - break; + iio_device_claim_direct_scoped(return -EBUSY, indio_dev) { + guard(mutex)(&st->lock); + switch (chan->type) { + case IIO_STEPS: + *val = st->steps; + return IIO_VAL_INT; + case IIO_ACTIVITY: + switch (chan->channel2) { + case IIO_MOD_RUNNING: + *val = st->activity_running; + return IIO_VAL_INT; + case IIO_MOD_WALKING: + *val = st->activity_walking; + return IIO_VAL_INT; + default: + return -EINVAL; + } default: - break; + return -EINVAL; } - break; - default: - break; } - break; + unreachable(); case IIO_CHAN_INFO_OFFSET: /* only single ended adc -> 7 */ *val = 7; - ret = IIO_VAL_INT; - break; + return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: switch (chan->type) { case IIO_VOLTAGE: @@ -350,60 +348,57 @@ static int iio_dummy_read_raw(struct iio_dev *indio_dev, /* only single ended adc -> 0.001333 */ *val = 0; *val2 = 1333; - ret = IIO_VAL_INT_PLUS_MICRO; - break; + return IIO_VAL_INT_PLUS_MICRO; case 1: /* all differential adc -> 0.000001344 */ *val = 0; *val2 = 1344; - ret = IIO_VAL_INT_PLUS_NANO; + return IIO_VAL_INT_PLUS_NANO; + default: + return -EINVAL; } - break; default: - break; + return -EINVAL; } - break; - case IIO_CHAN_INFO_CALIBBIAS: + case IIO_CHAN_INFO_CALIBBIAS: { + guard(mutex)(&st->lock); /* only the acceleration axis - read from cache */ *val = st->accel_calibbias; - ret = IIO_VAL_INT; - break; - case IIO_CHAN_INFO_CALIBSCALE: + return IIO_VAL_INT; + } + case IIO_CHAN_INFO_CALIBSCALE: { + guard(mutex)(&st->lock); *val = st->accel_calibscale->val; *val2 = st->accel_calibscale->val2; - ret = IIO_VAL_INT_PLUS_MICRO; - break; + return IIO_VAL_INT_PLUS_MICRO; + } case IIO_CHAN_INFO_SAMP_FREQ: *val = 3; *val2 = 33; - ret = IIO_VAL_INT_PLUS_NANO; - break; - case IIO_CHAN_INFO_ENABLE: + return IIO_VAL_INT_PLUS_NANO; + case IIO_CHAN_INFO_ENABLE: { + guard(mutex)(&st->lock); switch (chan->type) { case IIO_STEPS: *val = st->steps_enabled; - ret = IIO_VAL_INT; - break; + return IIO_VAL_INT; default: - break; + return -EINVAL; } - break; - case IIO_CHAN_INFO_CALIBHEIGHT: + } + case IIO_CHAN_INFO_CALIBHEIGHT: { + guard(mutex)(&st->lock); switch (chan->type) { case IIO_STEPS: *val = st->height; - ret = IIO_VAL_INT; - break; + return IIO_VAL_INT; default: - break; + return -EINVAL; } - break; - + } default: - break; + return -EINVAL; } - mutex_unlock(&st->lock); - return ret; } /** @@ -436,10 +431,10 @@ static int iio_dummy_write_raw(struct iio_dev *indio_dev, if (chan->output == 0) return -EINVAL; - /* Locking not required as writing single value */ - mutex_lock(&st->lock); - st->dac_val = val; - mutex_unlock(&st->lock); + scoped_guard(mutex, &st->lock) { + /* Locking not required as writing single value */ + st->dac_val = val; + } return 0; default: return -EINVAL; @@ -447,9 +442,9 @@ static int iio_dummy_write_raw(struct iio_dev *indio_dev, case IIO_CHAN_INFO_PROCESSED: switch (chan->type) { case IIO_STEPS: - mutex_lock(&st->lock); - st->steps = val; - mutex_unlock(&st->lock); + scoped_guard(mutex, &st->lock) { + st->steps = val; + } return 0; case IIO_ACTIVITY: if (val < 0) @@ -470,30 +465,29 @@ static int iio_dummy_write_raw(struct iio_dev *indio_dev, default: return -EINVAL; } - case IIO_CHAN_INFO_CALIBSCALE: - mutex_lock(&st->lock); + case IIO_CHAN_INFO_CALIBSCALE: { + guard(mutex)(&st->lock); /* Compare against table - hard matching here */ for (i = 0; i < ARRAY_SIZE(dummy_scales); i++) if (val == dummy_scales[i].val && val2 == dummy_scales[i].val2) break; if (i == ARRAY_SIZE(dummy_scales)) - ret = -EINVAL; - else - st->accel_calibscale = &dummy_scales[i]; - mutex_unlock(&st->lock); + return -EINVAL; + st->accel_calibscale = &dummy_scales[i]; return ret; + } case IIO_CHAN_INFO_CALIBBIAS: - mutex_lock(&st->lock); - st->accel_calibbias = val; - mutex_unlock(&st->lock); + scoped_guard(mutex, &st->lock) { + st->accel_calibbias = val; + } return 0; case IIO_CHAN_INFO_ENABLE: switch (chan->type) { case IIO_STEPS: - mutex_lock(&st->lock); - st->steps_enabled = val; - mutex_unlock(&st->lock); + scoped_guard(mutex, &st->lock) { + st->steps_enabled = val; + } return 0; default: return -EINVAL;