sandbox: add ADC unit tests

This commit adds unit tests for ADC uclass's methods using sandbox ADC.

Testing proper ADC binding:
- dm_test_adc_bind()                    - device binding
- dm_test_adc_wrong_channel_selection() - checking wrong channel selection

Testing ADC supply operations:
- dm_test_adc_supply():
  - Vdd/Vss values validating
  - Vdd regulator updated value validating
  - Vdd regulator's auto enable state validating

Testing ADC operations results:
- dm_test_adc_single_channel_conversion() - single channel start/data
- dm_test_adc_single_channel_shot()       - single channel shot
- dm_test_adc_multi_channel_conversion()  - multi channel start/data
- dm_test_adc_multi_channel_shot()        - multi channel single shot

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
diff --git a/test/dm/adc.c b/test/dm/adc.c
new file mode 100644
index 0000000..b0d4fe5
--- /dev/null
+++ b/test/dm/adc.c
@@ -0,0 +1,165 @@
+/*
+ * Tests for the driver model ADC API
+ *
+ * Copyright (c) 2015 Samsung Electronics
+ * Przemyslaw Marczak <p.marczak@samsung.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <adc.h>
+#include <dm.h>
+#include <dm/root.h>
+#include <dm/util.h>
+#include <dm/test.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <power/regulator.h>
+#include <power/sandbox_pmic.h>
+#include <sandbox-adc.h>
+#include <test/ut.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static int dm_test_adc_bind(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+
+	ut_assertok(uclass_get_device_by_name(UCLASS_ADC, "adc", &dev));
+	ut_asserteq_str(SANDBOX_ADC_DEVNAME, dev->name);
+
+	return 0;
+}
+DM_TEST(dm_test_adc_bind, DM_TESTF_SCAN_FDT);
+
+static int dm_test_adc_wrong_channel_selection(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+
+	ut_assertok(uclass_get_device_by_name(UCLASS_ADC, "adc", &dev));
+	ut_asserteq(-EINVAL, adc_start_channel(dev, SANDBOX_ADC_CHANNELS));
+
+	return 0;
+}
+DM_TEST(dm_test_adc_wrong_channel_selection, DM_TESTF_SCAN_FDT);
+
+static int dm_test_adc_supply(struct unit_test_state *uts)
+{
+	struct udevice *supply;
+	struct udevice *dev;
+	int uV;
+
+	ut_assertok(uclass_get_device_by_name(UCLASS_ADC, "adc", &dev));
+
+	/* Test Vss value - predefined 0 uV */
+	ut_assertok(adc_vss_value(dev, &uV));
+	ut_asserteq(SANDBOX_ADC_VSS_VALUE, uV);
+
+	/* Test Vdd initial value - buck2 */
+	ut_assertok(adc_vdd_value(dev, &uV));
+	ut_asserteq(SANDBOX_BUCK2_INITIAL_EXPECTED_UV, uV);
+
+	/* Change Vdd value - buck2 manual preset */
+	ut_assertok(regulator_get_by_devname(SANDBOX_BUCK2_DEVNAME, &supply));
+	ut_assertok(regulator_set_value(supply, SANDBOX_BUCK2_SET_UV));
+	ut_asserteq(SANDBOX_BUCK2_SET_UV, regulator_get_value(supply));
+
+	/* Update ADC platdata and get new Vdd value */
+	ut_assertok(adc_vdd_value(dev, &uV));
+	ut_asserteq(SANDBOX_BUCK2_SET_UV, uV);
+
+	/* Disable buck2 and test ADC supply enable function */
+	ut_assertok(regulator_set_enable(supply, false));
+	ut_asserteq(false, regulator_get_enable(supply));
+	/* adc_start_channel() should enable the supply regulator */
+	ut_assertok(adc_start_channel(dev, 0));
+	ut_asserteq(true, regulator_get_enable(supply));
+
+	return 0;
+}
+DM_TEST(dm_test_adc_supply, DM_TESTF_SCAN_FDT);
+
+struct adc_channel adc_channel_test_data[] = {
+	{ 0, SANDBOX_ADC_CHANNEL0_DATA },
+	{ 1, SANDBOX_ADC_CHANNEL1_DATA },
+	{ 2, SANDBOX_ADC_CHANNEL2_DATA },
+	{ 3, SANDBOX_ADC_CHANNEL3_DATA },
+};
+
+static int dm_test_adc_single_channel_conversion(struct unit_test_state *uts)
+{
+	struct adc_channel *tdata = adc_channel_test_data;
+	unsigned int i, data;
+	struct udevice *dev;
+
+	ut_assertok(uclass_get_device_by_name(UCLASS_ADC, "adc", &dev));
+	/* Test each ADC channel's value */
+	for (i = 0; i < SANDBOX_ADC_CHANNELS; i++, tdata++) {
+		ut_assertok(adc_start_channel(dev, tdata->id));
+		ut_assertok(adc_channel_data(dev, tdata->id, &data));
+		ut_asserteq(tdata->data, data);
+	}
+
+	return 0;
+}
+DM_TEST(dm_test_adc_single_channel_conversion, DM_TESTF_SCAN_FDT);
+
+static int dm_test_adc_multi_channel_conversion(struct unit_test_state *uts)
+{
+	struct adc_channel channels[SANDBOX_ADC_CHANNELS];
+	struct udevice *dev;
+	struct adc_channel *tdata = adc_channel_test_data;
+	unsigned int i, channel_mask;
+
+	channel_mask = ADC_CHANNEL(0) | ADC_CHANNEL(1) |
+		       ADC_CHANNEL(2) | ADC_CHANNEL(3);
+
+	/* Start multi channel conversion */
+	ut_assertok(uclass_get_device_by_name(UCLASS_ADC, "adc", &dev));
+	ut_assertok(adc_start_channels(dev, channel_mask));
+	ut_assertok(adc_channels_data(dev, channel_mask, channels));
+
+	/* Compare the expected and returned conversion data. */
+	for (i = 0; i < SANDBOX_ADC_CHANNELS; i++, tdata++)
+		ut_asserteq(tdata->data, channels[i].data);
+
+	return 0;
+}
+DM_TEST(dm_test_adc_multi_channel_conversion, DM_TESTF_SCAN_FDT);
+
+static int dm_test_adc_single_channel_shot(struct unit_test_state *uts)
+{
+	struct adc_channel *tdata = adc_channel_test_data;
+	unsigned int i, data;
+
+	for (i = 0; i < SANDBOX_ADC_CHANNELS; i++, tdata++) {
+		/* Start single channel conversion */
+		ut_assertok(adc_channel_single_shot("adc", tdata->id, &data));
+		/* Compare the expected and returned conversion data. */
+		ut_asserteq(tdata->data, data);
+	}
+
+	return 0;
+}
+DM_TEST(dm_test_adc_single_channel_shot, DM_TESTF_SCAN_FDT);
+
+static int dm_test_adc_multi_channel_shot(struct unit_test_state *uts)
+{
+	struct adc_channel channels[SANDBOX_ADC_CHANNELS];
+	struct adc_channel *tdata = adc_channel_test_data;
+	unsigned int i, channel_mask;
+
+	channel_mask = ADC_CHANNEL(0) | ADC_CHANNEL(1) |
+		       ADC_CHANNEL(2) | ADC_CHANNEL(3);
+
+	/* Start single call and multi channel conversion */
+	ut_assertok(adc_channels_single_shot("adc", channel_mask, channels));
+
+	/* Compare the expected and returned conversion data. */
+	for (i = 0; i < SANDBOX_ADC_CHANNELS; i++, tdata++)
+		ut_asserteq(tdata->data, channels[i].data);
+
+	return 0;
+}
+DM_TEST(dm_test_adc_multi_channel_shot, DM_TESTF_SCAN_FDT);