ec: Parse battery and augmented PDOs correctly.

Fixes pd_extract_pdo_power() to output the correct voltage and current
for non-fixed PDOs.  Add unit test.

BRANCH=servo
BUG=b:178484932
TEST=added

Signed-off-by: Jeremy Bettis <jbettis@google.com>
Change-Id: I791de41f00d75306a377e1ab9fb54409d5f537e7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2827325
Commit-Queue: Jeremy Bettis <jbettis@chromium.org>
Tested-by: Jeremy Bettis <jbettis@chromium.org>
Reviewed-by: Brian Nemec <bnemec@chromium.org>

3 files changed, 155 insertions, 18 deletions

diff --git a/common/usb_common.c b/common/usb_common.c
index 970152d4f9..a00a85e469 100644
--- a/common/usb_common.c
+++ b/common/usb_common.c
@@ -256,32 +256,40 @@ int pd_find_pdo_index(uint32_t src_cap_cnt, const uint32_t * const src_caps,
 void pd_extract_pdo_power(uint32_t pdo, uint32_t *ma, uint32_t *max_mv,
 			  uint32_t *min_mv)
 {
-	uint32_t max_ma, uw;
-
-	if ((pdo & PDO_TYPE_MASK) == PDO_TYPE_AUGMENTED) {
-		max_ma = 50 * (pdo & GENMASK(6, 0));
-		*min_mv = 100 * ((pdo & GENMASK(15, 8)) >> 8);
-		*max_mv = 100 * ((pdo & GENMASK(24, 17)) >> 17);
-		max_ma = MIN(max_ma, PD_MAX_POWER_MW * 1000 / *min_mv);
-		*ma = MIN(max_ma, PD_MAX_CURRENT_MA);
-		return;
+	int max_ma, mw;
+
+	if ((pdo & PDO_TYPE_MASK) == PDO_TYPE_FIXED) {
+		*max_mv = PDO_FIXED_VOLTAGE(pdo);
+		*min_mv = *max_mv;
+	} else if ((pdo & PDO_TYPE_MASK) == PDO_TYPE_AUGMENTED) {
+		*max_mv = PDO_AUG_MAX_VOLTAGE(pdo);
+		*min_mv = PDO_AUG_MIN_VOLTAGE(pdo);
+	} else if ((pdo & PDO_TYPE_MASK) == PDO_TYPE_VARIABLE) {
+		*max_mv = PDO_VAR_MAX_VOLTAGE(pdo);
+		*min_mv = PDO_VAR_MIN_VOLTAGE(pdo);
+	} else {
+		*max_mv = PDO_BATT_MAX_VOLTAGE(pdo);
+		*min_mv = PDO_BATT_MIN_VOLTAGE(pdo);
 	}
 
-	*max_mv = ((pdo >> 10) & 0x3FF) * 50;
 	if (*max_mv == 0) {
 		*ma = 0;
 		*min_mv = 0;
 		return;
 	}
-	if ((pdo & PDO_TYPE_MASK) == PDO_TYPE_BATTERY) {
-		uw = 250000 * (pdo & 0x3FF);
-		max_ma = 1000 * MIN(1000 * uw, PD_MAX_POWER_MW) / *max_mv;
+
+	if ((pdo & PDO_TYPE_MASK) == PDO_TYPE_FIXED) {
+		max_ma = PDO_FIXED_CURRENT(pdo);
+	} else if ((pdo & PDO_TYPE_MASK) == PDO_TYPE_AUGMENTED) {
+		max_ma = PDO_AUG_MAX_CURRENT(pdo);
+	} else if ((pdo & PDO_TYPE_MASK) == PDO_TYPE_VARIABLE) {
+		max_ma = PDO_VAR_MAX_CURRENT(pdo);
 	} else {
-		max_ma = 10 * (pdo & 0x3FF);
-		max_ma = MIN(max_ma, PD_MAX_POWER_MW * 1000 / *max_mv);
+		mw = PDO_BATT_MAX_POWER(pdo);
+		max_ma = 1000 * mw / *min_mv;
 	}
+	max_ma = MIN(max_ma, PD_MAX_POWER_MW * 1000 / *min_mv);
 	*ma = MIN(max_ma, PD_MAX_CURRENT_MA);
-	*min_mv = *max_mv;
 }
 
 void pd_build_request(uint32_t src_cap_cnt, const uint32_t * const src_caps,
diff --git a/include/usb_common.h b/include/usb_common.h
index 04495a17b0..27f48e579b 100644
--- a/include/usb_common.h
+++ b/include/usb_common.h
@@ -93,8 +93,8 @@ int pd_find_pdo_index(uint32_t src_cap_cnt, const uint32_t * const src_caps,
  *
  * @param pdo raw pdo to extract
  * @param ma current of the PDO (output)
- * @param mv voltage of the PDO, or max_mv of the Augmented PDO (output)
- * @param mv voltage of the PDO, or min_mv of the Augmented PDO (output)
+ * @param max_mv maximum voltage of the PDO (output)
+ * @param min_mv minimum voltage of the PDO (output)
  */
 void pd_extract_pdo_power(uint32_t pdo, uint32_t *ma, uint32_t *max_mv,
 			  uint32_t *min_mv);
diff --git a/test/usb_common_test.c b/test/usb_common_test.c
index d054f4ead2..c657d67455 100644
--- a/test/usb_common_test.c
+++ b/test/usb_common_test.c
@@ -66,9 +66,138 @@ int test_pd_get_cc_state(void)
 	return EC_SUCCESS;
 }
 
+/*
+ * From USB Power Delivery Specification Revision 3.0, Version 2.0
+ * Table 6-7 Power Data Object
+ */
+#define MAKE_FIXED(v, c) (0 << 30 | (v / 50) << 10 | (c / 10))
+#define MAKE_BATT(v_max, v_min, p) \
+	(1 << 30 | (v_max / 50) << 20 | (v_min / 50) << 10 | (p / 250))
+#define MAKE_VAR(v_max, v_min, c) \
+	(2 << 30 | (v_max / 50) << 20 | (v_min / 50) << 10 | (c / 10))
+#define MAKE_AUG(v_max, v_min, c) \
+	(3 << 30 | (v_max / 100) << 17 | (v_min / 100) << 8 | (c / 50))
+
+/*
+ * Tests various cases for pd_extract_pdo_power. It takes a very high voltage to
+ * exceed PD_MAX_POWER_MW without also exceeding PD_MAX_CURRENT_MA, so those
+ * tests are not particularly realistic.
+ */
+int test_pd_extract_pdo_power(void)
+{
+	uint32_t ma;
+	uint32_t max_mv;
+	uint32_t min_mv;
+
+	pd_extract_pdo_power(MAKE_FIXED(/*v=*/5000, /*c=*/3000), &ma, &max_mv,
+			     &min_mv);
+	TEST_EQ(max_mv, 5000, "%d");
+	TEST_EQ(min_mv, 5000, "%d");
+	TEST_EQ(ma, 3000, "%d");
+	pd_extract_pdo_power(MAKE_FIXED(/*v=*/20000, /*c=*/2600), &ma, &max_mv,
+			     &min_mv);
+	TEST_EQ(max_mv, 20000, "%d");
+	TEST_EQ(min_mv, 20000, "%d");
+	TEST_EQ(ma, 2600, "%d");
+	pd_extract_pdo_power(MAKE_FIXED(/*v=*/20000, /*c=*/4000), &ma, &max_mv,
+			     &min_mv);
+	TEST_EQ(max_mv, 20000, "%d");
+	TEST_EQ(min_mv, 20000, "%d");
+	TEST_EQ(ma, 3000, "%d"); /* Capped at PD_MAX_CURRENT_MA */
+	pd_extract_pdo_power(MAKE_FIXED(/*v=*/10000, /*c=*/4000), &ma, &max_mv,
+			     &min_mv);
+	TEST_EQ(max_mv, 10000, "%d");
+	TEST_EQ(min_mv, 10000, "%d");
+	TEST_EQ(ma, 3000, "%d"); /* Capped at PD_MAX_CURRENT_MA */
+	pd_extract_pdo_power(MAKE_FIXED(/*v=*/21000, /*c=*/4000), &ma, &max_mv,
+			     &min_mv);
+	TEST_EQ(max_mv, 21000, "%d");
+	TEST_EQ(min_mv, 21000, "%d");
+	TEST_EQ(ma, 2857, "%d"); /* Capped at PD_MAX_POWER_MW */
+
+	pd_extract_pdo_power(MAKE_BATT(/*v_max=*/5700, /*v_min=*/3300,
+				       /*p=*/7000),
+			     &ma, &max_mv, &min_mv);
+	TEST_EQ(max_mv, 5700, "%d");
+	TEST_EQ(min_mv, 3300, "%d");
+	TEST_EQ(ma, 2121, "%d"); /* 3300mV * 2121mA ~= 7000mW */
+	pd_extract_pdo_power(MAKE_BATT(/*v_max=*/3300, /*v_min=*/2700,
+				       /*p=*/12000),
+			     &ma, &max_mv, &min_mv);
+	TEST_EQ(max_mv, 3300, "%d");
+	TEST_EQ(min_mv, 2700, "%d");
+	TEST_EQ(ma, 3000, "%d"); /* Capped at PD_MAX_CURRENT_MA */
+
+	pd_extract_pdo_power(MAKE_BATT(/*v_max=*/25000, /*v_min=*/21000,
+				       /*p=*/61000),
+			     &ma, &max_mv, &min_mv);
+	TEST_EQ(max_mv, 25000, "%d");
+	TEST_EQ(min_mv, 21000, "%d");
+	TEST_EQ(ma, 2857, "%d"); /* Capped at PD_MAX_POWER_MW */
+
+	pd_extract_pdo_power(MAKE_VAR(/*v_max=*/5000, /*v_min=*/3300,
+				      /*c=*/3000),
+			     &ma, &max_mv, &min_mv);
+	TEST_EQ(max_mv, 5000, "%d");
+	TEST_EQ(min_mv, 3300, "%d");
+	TEST_EQ(ma, 3000, "%d");
+	pd_extract_pdo_power(MAKE_VAR(/*v_max=*/20000, /*v_min=*/5000,
+				      /*c=*/2600),
+			     &ma, &max_mv, &min_mv);
+	TEST_EQ(max_mv, 20000, "%d");
+	TEST_EQ(min_mv, 5000, "%d");
+	TEST_EQ(ma, 2600, "%d");
+	pd_extract_pdo_power(MAKE_VAR(/*v_max=*/20000, /*v_min=*/5000,
+				      /*c=*/4000),
+			     &ma, &max_mv, &min_mv);
+	TEST_EQ(max_mv, 20000, "%d");
+	TEST_EQ(min_mv, 5000, "%d");
+	TEST_EQ(ma, 3000, "%d"); /* Capped at PD_MAX_CURRENT_MA */
+	pd_extract_pdo_power(MAKE_VAR(/*v_max=*/10000, /*v_min=*/3300,
+				      /*c=*/4000),
+			     &ma, &max_mv, &min_mv);
+	TEST_EQ(max_mv, 10000, "%d");
+	TEST_EQ(min_mv, 3300, "%d");
+	TEST_EQ(ma, 3000, "%d"); /* Capped at PD_MAX_CURRENT_MA */
+	pd_extract_pdo_power(MAKE_VAR(/*v_max=*/22000, /*v_min=*/21000,
+				      /*c=*/4000),
+			     &ma, &max_mv, &min_mv);
+	TEST_EQ(max_mv, 22000, "%d");
+	TEST_EQ(min_mv, 21000, "%d");
+	TEST_EQ(ma, 2857, "%d"); /* Capped at PD_MAX_POWER_MW */
+
+	pd_extract_pdo_power(MAKE_AUG(/*v_max=*/5000, /*v_min=*/3300,
+				      /*c=*/3000),
+			     &ma, &max_mv, &min_mv);
+	TEST_EQ(max_mv, 5000, "%d");
+	TEST_EQ(min_mv, 3300, "%d");
+	TEST_EQ(ma, 3000, "%d");
+	pd_extract_pdo_power(MAKE_AUG(/*v_max=*/20000, /*v_min=*/3300,
+				      /*c=*/2600),
+			     &ma, &max_mv, &min_mv);
+	TEST_EQ(max_mv, 20000, "%d");
+	TEST_EQ(min_mv, 3300, "%d");
+	TEST_EQ(ma, 2600, "%d");
+	pd_extract_pdo_power(MAKE_AUG(/*v_max=*/10000, /*v_min=*/3300,
+				      /*c=*/4000),
+			     &ma, &max_mv, &min_mv);
+	TEST_EQ(max_mv, 10000, "%d");
+	TEST_EQ(min_mv, 3300, "%d");
+	TEST_EQ(ma, 3000, "%d"); /* Capped at PD_MAX_CURRENT_MA */
+	pd_extract_pdo_power(MAKE_AUG(/*v_max=*/22000, /*v_min=*/21000,
+				      /*c=*/4000),
+			     &ma, &max_mv, &min_mv);
+	TEST_EQ(max_mv, 22000, "%d");
+	TEST_EQ(min_mv, 21000, "%d");
+	TEST_EQ(ma, 2857, "%d"); /* Capped at PD_MAX_POWER_MW */
+
+	return EC_SUCCESS;
+}
+
 void run_test(void)
 {
 	RUN_TEST(test_pd_get_cc_state);
+	RUN_TEST(test_pd_extract_pdo_power);
 
 	test_print_result();
 }