From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 10 Jun 2014 17:19:13 +0200 From: Alexandre Belloni To: Robert Hodaszi Cc: jic23@kernel.org, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, marex@denx.de, jbe@pengutronix.de, hector.palacios@digi.com, fabio.estevam@freescale.com, lars@metafoo.de Subject: Re: [PATCH 1/2] iio: mxs-lradc: fix divider Message-ID: <20140610151912.GA3429@piout.net> References: <1402407695-2984-1-git-send-email-robert.hodaszi@digi.com> <1402407695-2984-2-git-send-email-robert.hodaszi@digi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1402407695-2984-2-git-send-email-robert.hodaszi@digi.com> List-ID: On 10/06/2014 at 15:41:34 +0200, Robert Hodaszi wrote : > All channels' single measurement are happening on CH 0. So enabling / disabling > the divider once is not enough, because it has impact on all channels. > > Set only a flag, then check this on each measurement, and enable / disable the > divider as required. > > Signed-off-by: Robert Hodaszi It makes perfect sense. Acked-by: Alexandre Belloni > --- > drivers/staging/iio/adc/mxs-lradc.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c > index dae8d1a..52d7517 100644 > --- a/drivers/staging/iio/adc/mxs-lradc.c > +++ b/drivers/staging/iio/adc/mxs-lradc.c > @@ -846,6 +846,14 @@ static int mxs_lradc_read_single(struct iio_dev *iio_dev, int chan, int *val) > LRADC_CTRL1); > mxs_lradc_reg_clear(lradc, 0xff, LRADC_CTRL0); > > + /* Enable / disable the divider per requirement */ > + if (test_bit(chan, &lradc->is_divided)) > + mxs_lradc_reg_set(lradc, 1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET, > + LRADC_CTRL2); > + else > + mxs_lradc_reg_clear(lradc, > + 1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET, LRADC_CTRL2); > + > /* Clean the slot's previous content, then set new one. */ > mxs_lradc_reg_clear(lradc, LRADC_CTRL4_LRADCSELECT_MASK(0), > LRADC_CTRL4); > @@ -961,15 +969,11 @@ static int mxs_lradc_write_raw(struct iio_dev *iio_dev, > if (val == scale_avail[MXS_LRADC_DIV_DISABLED].integer && > val2 == scale_avail[MXS_LRADC_DIV_DISABLED].nano) { > /* divider by two disabled */ > - writel(1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET, > - lradc->base + LRADC_CTRL2 + STMP_OFFSET_REG_CLR); > clear_bit(chan->channel, &lradc->is_divided); > ret = 0; > } else if (val == scale_avail[MXS_LRADC_DIV_ENABLED].integer && > val2 == scale_avail[MXS_LRADC_DIV_ENABLED].nano) { > /* divider by two enabled */ > - writel(1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET, > - lradc->base + LRADC_CTRL2 + STMP_OFFSET_REG_SET); > set_bit(chan->channel, &lradc->is_divided); > ret = 0; > } -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com