mp4245: Buck boost converter initial driver

This CL adds support for the MPS mp4245 buck-boost converter which is
designed to be used for USB PD Vbus generation.

BUG=b:169312229
BRANCH=None
TEST=verfied type-c attaches properly on quiche

Signed-off-by: Scott Collyer <scollyer@google.com>
Change-Id: Ie6c79a5509c6a85f9d6bcb95d4053f2803ca1ad4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2436571
Tested-by: Scott Collyer <scollyer@chromium.org>
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>
Commit-Queue: Scott Collyer <scollyer@chromium.org>

1 files changed, 190 insertions, 0 deletions

diff --git a/driver/mp4245.c b/driver/mp4245.c
new file mode 100644
index 0000000000..9ab56fe894
--- /dev/null
+++ b/driver/mp4245.c
@@ -0,0 +1,190 @@
+/* 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.
+ */
+
+/* MPS MP4245 Buck-Boost converter driver. */
+
+#include "common.h"
+#include "console.h"
+#include "i2c.h"
+#include "mp4245.h"
+#include "util.h"
+
+
+static int mp4245_reg16_write(int offset, int data)
+{
+	return i2c_write16(I2C_PORT_MP4245, MP4245_SLAVE_ADDR, offset,
+			   data);
+}
+
+int mp4245_set_voltage_out(int desired_mv)
+{
+	int vout;
+
+	/*
+	 * For a desired voltage output Vdes, Vout = Vdes * 1024. This means
+	 * there are 10 fractional and 6 integer bits. Vdes is stored in in mV
+	 * so this scaling to mV must also be accounted for.
+	 *
+	 * VOUT_COMMAND = (Vdes (mV) * 1024 / 1000) / 1024
+	 */
+	vout = (desired_mv * MP4245_VOUT_FROM_MV + (MP4245_VOUT_1V >> 1))
+		/ MP4245_VOUT_1V;
+
+	return mp4245_reg16_write(MP4245_CMD_VOUT_COMMAND, vout);
+}
+
+int mp4245_set_current_lim(int desired_ma)
+{
+	int limit;
+
+	/* Current limit is stored as number of 50 mA steps */
+	limit = (desired_ma + (MP4245_ILIM_STEP_MA / 2)) / MP4245_ILIM_STEP_MA;
+
+	return mp4245_reg16_write(MP4245_CMD_MFR_CURRENT_LIM, limit);
+}
+
+int mp4245_votlage_out_enable(int enable)
+{
+	int cmd_val = enable ? MP4245_CMD_OPERATION_ON : 0;
+
+	return i2c_write8(I2C_PORT_MP4245, MP4245_SLAVE_ADDR,
+			MP4245_CMD_OPERATION, cmd_val);
+}
+
+struct mp4245_info {
+	uint8_t cmd;
+	uint8_t len;
+};
+
+static struct mp4245_info  mp4245_cmds[] = {
+	{MP4245_CMD_OPERATION,          1},
+	{MP4245_CMD_CLEAR_FAULTS,       1},
+	{MP4245_CMD_WRITE_PROTECT,      1},
+	{MP4245_CMD_STORE_USER_ALL,     1},
+	{MP4245_CMD_RESTORE_USER_ALL,   1},
+	{MP4245_CMD_VOUT_MODE,          1},
+	{MP4245_CMD_VOUT_COMMAND,       2},
+	{MP4245_CMD_VOUT_SCALE_LOOP,    2},
+	{MP4245_CMD_STATUS_BYTE,        1},
+	{MP4245_CMD_STATUS_WORD,        2},
+	{MP4245_CMD_STATUS_VOUT,        1},
+	{MP4245_CMD_STATUS_INPUT,       1},
+	{MP4245_CMD_STATUS_TEMP,        1},
+	{MP4245_CMD_STATUS_CML,         1},
+	{MP4245_CMD_READ_VIN,           2},
+	{MP4245_CMD_READ_VOUT,          2},
+	{MP4245_CMD_READ_IOUT,          2},
+	{MP4245_CMD_READ_TEMP,          2},
+	{MP4245_CMD_MFR_MODE_CTRL,      1},
+	{MP4245_CMD_MFR_CURRENT_LIM,    1},
+	{MP4245_CMD_MFR_LINE_DROP,      1},
+	{MP4245_CMD_MFR_OT_FAULT_LIM,   1},
+	{MP4245_CMD_MFR_OT_WARN_LIM,    1},
+	{MP4245_CMD_MFR_CRC_ERROR,      1},
+	{MP4245_CMD_MFF_MTP_CFG_CODE,   1},
+	{MP4245_CMD_MFR_MTP_REV_NUM,    1},
+	{MP4245_CMD_MFR_STATUS_MASK,    1},
+};
+
+static void mp4245_dump_reg(void)
+{
+	int i;
+	int val;
+	int rv;
+
+	for (i = 0; i < ARRAY_SIZE(mp4245_cmds); i++) {
+		if (mp4245_cmds[i].len == 1) {
+			rv = i2c_read8(I2C_PORT_MP4245, MP4245_SLAVE_ADDR,
+				       mp4245_cmds[i].cmd, &val);
+		} else {
+			rv = i2c_read16(I2C_PORT_MP4245, MP4245_SLAVE_ADDR,
+				       mp4245_cmds[i].cmd, &val);
+		}
+
+		if (!rv)
+			ccprintf("[%02x]:\t%04x\n", mp4245_cmds[i].cmd, val);
+	}
+}
+
+void mp4245_get_status(void)
+{
+	int status;
+	int on;
+	int vbus;
+	int ibus;
+	int ilim;
+	int vout;
+
+	/* Get Operation register */
+	i2c_read8(I2C_PORT_MP4245, MP4245_SLAVE_ADDR,
+		  MP4245_CMD_OPERATION, &on);
+	/* Vbus on/off is bit 7 */
+	on >>= 7;
+
+	/* Get status word */
+	i2c_read16(I2C_PORT_MP4245, MP4245_SLAVE_ADDR,
+		  MP4245_CMD_STATUS_WORD, &status);
+
+	/* Get Vbus measurement */
+	i2c_read16(I2C_PORT_MP4245, MP4245_SLAVE_ADDR,
+		   MP4245_CMD_READ_VOUT, &vbus);
+	vbus = MP4245_VOUT_TO_MV(vbus);
+
+	/* Get Ibus measurement */
+	i2c_read16(I2C_PORT_MP4245, MP4245_SLAVE_ADDR,
+		  MP4245_CMD_READ_IOUT, &ibus);
+	ibus = MP4245_IOUT_TO_MA(ibus);
+
+	/* Get Vout command (sets Vbus level) */
+	i2c_read16(I2C_PORT_MP4245, MP4245_SLAVE_ADDR,
+		   MP4245_CMD_VOUT_COMMAND, &vout);
+	vout = MP4245_VOUT_TO_MV(vout);
+
+	/* Get Input current limit */
+	i2c_read8(I2C_PORT_MP4245, MP4245_SLAVE_ADDR,
+		   MP4245_CMD_MFR_CURRENT_LIM, &ilim);
+	ilim *= MP4245_ILIM_STEP_MA;
+
+	ccprintf("mp4245 Vbus %s:\n", on ? "On" : "Off");
+	ccprintf("\tstatus = 0x%04x\n", status);
+	ccprintf("\tVout   = %d mV, Vbus = %d mV\n", vout, vbus);
+	ccprintf("\tIlim   = %d mA, Ibus = %d mA\n", ilim, ibus);
+}
+
+static int command_mp4245(int argc, char **argv)
+{
+	char *e;
+	int val;
+
+	if (argc < 2)
+		return EC_ERROR_PARAM_COUNT;
+
+	if (!strcasecmp(argv[1], "info")) {
+		mp4245_get_status();
+	} else if (!strcasecmp(argv[1], "dump")) {
+		mp4245_dump_reg();
+	} else if (!strcasecmp(argv[1], "vbus")) {
+		if (argc < 3)
+			return EC_ERROR_PARAM_COUNT;
+		val = strtoi(argv[2], &e, 10);
+		/* If value out of bounds, turn off */
+		if (val < 0 || val > 20) {
+			return EC_ERROR_PARAM2;
+		}
+		if (val == 0) {
+			mp4245_votlage_out_enable(0);
+		} else {
+			mp4245_set_voltage_out(val * 1000);
+			mp4245_votlage_out_enable(1);
+		}
+	} else {
+		return EC_ERROR_PARAM1;
+	}
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(mp4245, command_mp4245,
+			"<info|dump|vbus|ilim>",
+			"Turn on/off|set vbus.");
+