it8380dev: add adc control module

Add adc control module for emulation board.
The ADC converts the input voltage signal ranging
from 0v to 3v into a 10-bit unsigned integer.

Signed-off-by: Dino Li <dino.li@ite.com.tw>

BRANCH=none
BUG=none
TEST=manual test.
1 - adc channel 1, 3, 5, and 7 to ground.
2 - adc channel 0 and 2 to 1.26v.
3 - adc channel 4 and 6 to 1.72v.
4 - condition, factor_mul = 3000, factor_div = 1024, and shift = 0.
5 - console "adc", result as following.
adc_ch0 = 1256
adc_ch1 = 0
adc_ch2 = 1256
adc_ch3 = 0
adc_ch4 = 1722
adc_ch5 = 0
adc_ch6 = 1725
adc_ch7 = 0

Change-Id: I72efd09c9f7dbff25c4f6fd4846c9b1c1e5637ca
Reviewed-on: https://chromium-review.googlesource.com/228092
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Commit-Queue: Dino Li <dino.li@ite.com.tw>
Tested-by: Dino Li <dino.li@ite.com.tw>

1 files changed, 34 insertions, 0 deletions

diff --git a/chip/it83xx/adc_chip.h b/chip/it83xx/adc_chip.h
new file mode 100644
index 0000000000..ae7ee403b0
--- /dev/null
+++ b/chip/it83xx/adc_chip.h
@@ -0,0 +1,34 @@
+/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* IT8380 ADC module for Chrome EC */
+
+#ifndef __CROS_EC_ADC_CHIP_H
+#define __CROS_EC_ADC_CHIP_H
+
+/* Data structure to define ADC channel control registers. */
+struct adc_ctrl_t {
+	volatile uint8_t *adc_ctrl;
+	volatile uint8_t *adc_datm;
+	volatile uint8_t *adc_datl;
+	volatile uint8_t *adc_pin_ctrl;
+};
+
+/* Data structure to define ADC channels. */
+struct adc_t {
+	const char *name;
+	int factor_mul;
+	int factor_div;
+	int shift;
+	int channel;
+};
+
+/*
+ * Boards must provide this list of ADC channel definitions. This must match
+ * the enum adc_channel list provided by the board.
+ */
+extern const struct adc_t adc_channels[];
+
+#endif /* __CROS_EC_ADC_CHIP_H */