[PATCH 3.14 54/68] iio: mxs-lradc: fix divider

Greg Kroah-Hartman
2014-06-24T16:21:46Z

From: Robert Hodaszi <robert.hodaszi@digi.com>

commit 19bc4981a213d0c5b0e1e8b08815c0b26f01ec54 upstream.

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 <robert.hodaszi@digi.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/staging/iio/adc/mxs-lradc.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

--- 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
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);
mxs_lradc_reg_set(lradc, chan, LRADC_CTRL4);
@@ -964,15 +972,11 @@ static int mxs_lradc_write_raw(struct ii
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;
}