Re: [PATCH 4/4] iio: ti_am335x_adc: Add continuous sampling and trigger support

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Zubair Lutfullah <zubair.lutfullah@gmail.com>
Cc: jic23@cam.ac.uk, dmitry.torokhov@gmail.com,
	linux-iio@vger.kernel.org, linux-input@vger.kernel.org,
	linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org,
	Russ.Dill@ti.com
Subject: Re: [PATCH 4/4] iio: ti_am335x_adc: Add continuous sampling and trigger support
Date: Fri, 16 Aug 2013 16:59:49 +0200	[thread overview]
Message-ID: <20130816145949.GE1263@linutronix.de> (raw)
In-Reply-To: <1376424303-22740-5-git-send-email-zubair.lutfullah@gmail.com>

* Zubair Lutfullah | 2013-08-13 21:05:03 [+0100]:

>diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
>index 3ceac3e..0d7e313 100644
>--- a/drivers/iio/adc/ti_am335x_adc.c
>+++ b/drivers/iio/adc/ti_am335x_adc.c
…

>+static int tiadc_buffer_postdisable(struct iio_dev *indio_dev)
>+{
>+	struct tiadc_device *adc_dev = iio_priv(indio_dev);
>+	int config;
>+
>+	tiadc_step_config(indio_dev);
>+	if (adc_dev->mfd_tscadc->tsc_cell == -1) {
>+		config = tiadc_readl(adc_dev, REG_CTRL);
>+		tiadc_writel(adc_dev, REG_CTRL, (config | CNTRLREG_TSCSSENB));
>+	}

This kind of check is bad. The tsc cell may have been created but the
driver not enabled or loaded. Further you should document why you need
to enable / disable the ADC in this places and only if the TSC part is
not active.

Sebastian