From: Bart Massey <bart.massey@gmail.com>
Date: Tue, 9 Feb 2016 02:55:28 +0000 (-0800)
Subject: Clean up stmf0 adc init.
X-Git-Tag: 1.6.3~2^2~101
X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=commitdiff_plain;h=e36117ccbf7cbe3704c6b44d3ad429e720a1e16c

Clean up stmf0 adc init.

This better matches the documented cal sequence.

Signed-off-by: Keith Packard <keithp@keithp.com>
---

diff --git a/src/stmf0/ao_adc_fast.c b/src/stmf0/ao_adc_fast.c
index 26e6691c..f6740b0e 100644
--- a/src/stmf0/ao_adc_fast.c
+++ b/src/stmf0/ao_adc_fast.c
@@ -83,7 +83,6 @@ void
 ao_adc_init(void)
 {
 	uint32_t	chselr;
-	int		i;
 
 	/* Reset ADC */
 	stm_rcc.apb2rstr |= (1 << STM_RCC_APB2RSTR_ADCRST);
@@ -157,12 +156,13 @@ ao_adc_init(void)
 	/* Shortest sample time */
 	stm_adc.smpr = STM_ADC_SMPR_SMP_1_5 << STM_ADC_SMPR_SMP;
 
+	/* Turn off enable and start */
+	stm_adc.cr &= ~((1 << STM_ADC_CR_ADEN) | (1 << STM_ADC_CR_ADSTART));
+
 	/* Calibrate */
 	stm_adc.cr |= (1 << STM_ADC_CR_ADCAL);
-	for (i = 0; i < 0xf000; i++) {
-		if ((stm_adc.cr & (1 << STM_ADC_CR_ADCAL)) == 0)
-			break;
-	}
+	while ((stm_adc.cr & (1 << STM_ADC_CR_ADCAL)) != 0)
+		;
 
 	/* Enable */
 	stm_adc.cr |= (1 << STM_ADC_CR_ADEN);