[PATCH 4.0 034/148] iio: adc: cc10001: Add delay before setting START bit

[Greg Kroah-Hartman]

4.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Naidu Tellapati <naidu.tellapati@xxxxxxxxxx>

commit f29b212edb9e253cafcb4a2ab7842a890989f1a5 upstream.

According to hardware team there should be some delay after
setting channel number, start mode and before setting START.
Add a one microsecond delay for this purpose.

Fixes: 1664f6a5b0c8 ("iio: adc: Cosmic Circuits 10001 ADC driver")
Signed-off-by: Naidu Tellapati <naidu.tellapati@xxxxxxxxxx>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@xxxxxxxxxx>
Signed-off-by: Jonathan Cameron <jic23@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/iio/adc/cc10001_adc.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/iio/adc/cc10001_adc.c
+++ b/drivers/iio/adc/cc10001_adc.c
@@ -100,6 +100,7 @@ static void cc10001_adc_start(struct cc1
 	val = (channel & CC10001_ADC_CH_MASK) | CC10001_ADC_MODE_SINGLE_CONV;
 	cc10001_adc_write_reg(adc_dev, CC10001_ADC_CONFIG, val);
 
+	udelay(1);
 	val = cc10001_adc_read_reg(adc_dev, CC10001_ADC_CONFIG);
 	val = val | CC10001_ADC_START_CONV;
 	cc10001_adc_write_reg(adc_dev, CC10001_ADC_CONFIG, val);


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