it83xx/dac: add DAC module

The DAC module has four channels. We can
set output voltage when DAC channel is
enabled by this driver.

BUG=b:149094279
BRANCH=none
TEST=The console command #dac set as follows:
read: dac [ch]
write: dac [ch] [voltage]
[ch]:2-5, [voltage]:0(disable)-3300

Change-Id: I8e815cb5bc749467581d5f771fd6f9e0995fca3b
Signed-off-by: tim <tim2.lin@ite.corp-partner.google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2046685
Reviewed-by: Diana Z <dzigterman@chromium.org>

1 files changed, 58 insertions, 0 deletions

diff --git a/chip/it83xx/dac_chip.h b/chip/it83xx/dac_chip.h
new file mode 100644
index 0000000000..fa50769c85
--- /dev/null
+++ b/chip/it83xx/dac_chip.h
@@ -0,0 +1,58 @@
+/* Copyright 2020 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.
+ */
+
+/* IT83xx DAC module for Chrome EC */
+
+#ifndef __CROS_EC_DAC_CHIP_H
+#define __CROS_EC_DAC_CHIP_H
+
+#define DAC_AVCC 3300
+/*
+ * Each channel generates an output ranging
+ * from 0V to AVCC with 8-bit resolution.
+ */
+#define DAC_RAW_DATA (BIT(8) - 1)
+
+/* List of DAC channels. */
+enum chip_dac_channel {
+	CHIP_DAC_CH2 = 2,
+	CHIP_DAC_CH3,
+	CHIP_DAC_CH4,
+	CHIP_DAC_CH5,
+};
+
+/**
+ * DAC module enable.
+ *
+ * @param ch		Channel to enable.
+ */
+void dac_enable_channel(enum chip_dac_channel ch);
+
+/**
+ * DAC module disable.
+ *
+ * @param ch		Channel to disable.
+ */
+void dac_disable_channel(enum chip_dac_channel ch);
+
+/**
+ * Set DAC output voltage.
+ *
+ * @param ch		Channel to set.
+ * @param mv		Setting ch output voltage.
+ */
+void dac_set_output_voltage(enum chip_dac_channel ch, int mv);
+
+/**
+ * Get DAC output voltage.
+ *
+ * @param ch		Channel to get.
+ *
+ * @return		Getting ch output voltage.
+ */
+int dac_get_output_voltage(enum chip_dac_channel ch);
+
+#endif /* __CROS_EC_DAC_CHIP_H */
+