From: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
According to the datasheet:
* 0 - external crystal, connected from pin MCLK1 to MCLK2
* 1 - external clock, applied to MCLK2 pin
* 2 - internal 4.92 Mhz clock; pin MCLK2 is tristated
* 3 - internal 4.92 Mhz clock; internal clock is available on MCLK2
Which means that the external clock value only has sense
for value 1 (AD7192_CLK_EXT_MCLK2).
Also added range validation for the external frequency
setting, which the datasheet mentions that it's
between 2.4576 and 5.12 Mhz.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
---
drivers/staging/iio/adc/ad7192.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c
index 7f204013d6d4..7bc04101d133 100644
--- a/drivers/staging/iio/adc/ad7192.c
+++ b/drivers/staging/iio/adc/ad7192.c
@@ -141,6 +141,8 @@
#define AD7192_GPOCON_P1DAT BIT(1) /* P1 state */
#define AD7192_GPOCON_P0DAT BIT(0) /* P0 state */
+#define AD7192_EXT_FREQ_MHZ_MIN 2457600
+#define AD7192_EXT_FREQ_MHZ_MAX 5120000
#define AD7192_INT_FREQ_MHZ 4915200
/* NOTE:
@@ -217,6 +219,12 @@ static int ad7192_calibrate_all(struct ad7192_state *st)
ARRAY_SIZE(ad7192_calib_arr));
}
+static inline bool ad7192_valid_external_frequency(u32 freq)
+{
+ return (freq >= AD7192_EXT_FREQ_MHZ_MIN &&
+ freq <= AD7192_EXT_FREQ_MHZ_MAX);
+}
+
static int ad7192_setup(struct ad7192_state *st,
const struct ad7192_platform_data *pdata)
{
@@ -245,16 +253,16 @@ static int ad7192_setup(struct ad7192_state *st,
switch (pdata->clock_source_sel) {
case AD7192_CLK_EXT_MCLK1_2:
- case AD7192_CLK_EXT_MCLK2:
- st->mclk = AD7192_INT_FREQ_MHZ;
- break;
case AD7192_CLK_INT:
case AD7192_CLK_INT_CO:
- if (pdata->ext_clk_hz)
- st->mclk = pdata->ext_clk_hz;
- else
- st->mclk = AD7192_INT_FREQ_MHZ;
+ st->mclk = AD7192_INT_FREQ_MHZ;
break;
+ case AD7192_CLK_EXT_MCLK2:
+ if (ad7192_valid_external_frequency(pdata->clock_source_sel)) {
+ st->mclk = pdata->clock_source_sel;
+ break;
+ }
+ /* FALLTHROUGH */
default:
ret = -EINVAL;
goto out;
--
2.14.1
--
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