twinkie: add config to behave as a PD message injector

Add a compile-time configuration to make Twinkie behave as
a USB Power Delivery consumer/provider device rather than a
transparent sniffer.

To use it, edit board/twinkie/ec.tasklist:
enable the PD task and comment out the SNIFFER task.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BRANCH=none
BUG=none
TEST=connect it to a Fruitpie and use "pd charger" command on Twinkie
console, see the Fruitpie receiving the source capabilities and
answering.

Change-Id: Ic2b4ba2d166ea1d3f5f9be410453a030a4ee7b68
Reviewed-on: https://chromium-review.googlesource.com/204168
Reviewed-by: Todd Broch <tbroch@chromium.org>
Commit-Queue: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>

1 files changed, 123 insertions, 0 deletions

diff --git a/board/twinkie/usb_pd_policy.c b/board/twinkie/usb_pd_policy.c
new file mode 100644
index 0000000000..a67c4bc2d6
--- /dev/null
+++ b/board/twinkie/usb_pd_policy.c
@@ -0,0 +1,123 @@
+/* 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.
+ */
+
+#include "common.h"
+#include "config.h"
+#include "console.h"
+#include "hooks.h"
+#include "registers.h"
+#include "task.h"
+#include "timer.h"
+#include "util.h"
+#include "usb_pd.h"
+
+#define CPRINTS(format, args...) cprints(CC_USBPD, format, ## args)
+
+const uint32_t pd_src_pdo[] = {
+		PDO_FIXED(5000,   500, PDO_FIXED_EXTERNAL),
+		PDO_FIXED(5000,  3000, 0),
+		PDO_FIXED(12000, 3000, 0),
+		PDO_FIXED(20000, 2000, 0),
+};
+const int pd_src_pdo_cnt = ARRAY_SIZE(pd_src_pdo);
+
+const uint32_t pd_snk_pdo[] = {
+		PDO_BATT(4500,   5500, 15000),
+		PDO_BATT(11500, 12500, 36000),
+};
+const int pd_snk_pdo_cnt = ARRAY_SIZE(pd_snk_pdo);
+
+/* Cap on the max voltage requested as a sink (in millivolts) */
+static unsigned max_mv = -1; /* no cap */
+
+int pd_choose_voltage(int cnt, uint32_t *src_caps, uint32_t *rdo)
+{
+	int i;
+	int sel_mv;
+	int max_uw = 0;
+	int max_i = -1;
+
+	/* Get max power */
+	for (i = 0; i < cnt; i++) {
+		int uw;
+		int mv = ((src_caps[i] >> 10) & 0x3FF) * 50;
+		if ((src_caps[i] & PDO_TYPE_MASK) == PDO_TYPE_BATTERY) {
+			uw = 250000 * (src_caps[i] & 0x3FF);
+		} else {
+			int ma = (src_caps[i] & 0x3FF) * 10;
+			uw = ma * mv;
+		}
+		if ((uw > max_uw) && (mv <= max_mv)) {
+			max_i = i;
+			max_uw = uw;
+			sel_mv = mv;
+		}
+	}
+	if (max_i < 0)
+		return -EC_ERROR_UNKNOWN;
+
+	/* request all the power ... */
+	if ((src_caps[max_i] & PDO_TYPE_MASK) == PDO_TYPE_BATTERY) {
+		int uw = 250000 * (src_caps[i] & 0x3FF);
+		*rdo = RDO_BATT(max_i + 1, uw/2, uw, 0);
+		ccprintf("Request [%d] %dV %d/%d mW\n",
+			 max_i, sel_mv/1000, uw/1000, uw/1000);
+	} else {
+		int ma = 10 * (src_caps[max_i] & 0x3FF);
+		*rdo = RDO_FIXED(max_i + 1, ma / 2, ma, 0);
+		ccprintf("Request [%d] %dV %d/%d mA\n",
+			 max_i, sel_mv/1000, max_i, ma/2, ma);
+	}
+	return EC_SUCCESS;
+}
+
+void pd_set_input_current_limit(uint32_t max_ma)
+{
+}
+
+void pd_set_max_voltage(unsigned mv)
+{
+	max_mv = mv;
+}
+
+int pd_request_voltage(uint32_t rdo)
+{
+	int op_ma = rdo & 0x3FF;
+	int max_ma = (rdo >> 10) & 0x3FF;
+	int idx = rdo >> 28;
+	uint32_t pdo;
+	uint32_t pdo_ma;
+
+	if (!idx || idx > pd_src_pdo_cnt)
+		return EC_ERROR_INVAL; /* Invalid index */
+
+	/* check current ... */
+	pdo = pd_src_pdo[idx - 1];
+	pdo_ma = (pdo & 0x3ff);
+	if (op_ma > pdo_ma)
+		return EC_ERROR_INVAL; /* too much op current */
+	if (max_ma > pdo_ma)
+		return EC_ERROR_INVAL; /* too much max current */
+
+	ccprintf("Switch to %d V %d mA (for %d/%d mA)\n",
+		 ((pdo >> 10) & 0x3ff) * 50, (pdo & 0x3ff) * 10,
+		 ((rdo >> 10) & 0x3ff) * 10, (rdo & 0x3ff) * 10);
+
+	return EC_SUCCESS;
+}
+
+int pd_set_power_supply_ready(int port)
+{
+	return EC_SUCCESS; /* we are ready */
+}
+
+void pd_power_supply_reset(int port)
+{
+}
+
+int pd_board_checks(void)
+{
+	return EC_SUCCESS;
+}