drivers/i2c/nct7802y: Add new hardware-monitoring IC

Just another hardware-monitoring chip. Only limited fan control and PECI
configuration is implemented.

Change-Id: I35ea79e12941804e398c6304a08170a776f4ca76
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/29475
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>

1 files changed, 111 insertions, 0 deletions

diff --git a/src/drivers/i2c/nct7802y/nct7802y_fan.c b/src/drivers/i2c/nct7802y/nct7802y_fan.c
new file mode 100644
index 0000000000..f0f3a3ced8
--- /dev/null
+++ b/src/drivers/i2c/nct7802y/nct7802y_fan.c
@@ -0,0 +1,111 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2017 secunet Security Networks AG
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <types.h>
+#include <device/device.h>
+
+#include "nct7802y.h"
+#include "chip.h"
+
+static void init_fan(struct device *const dev,
+		     const struct nct7802y_fan_config *const config,
+		     const unsigned int fan)
+{
+	unsigned int temp;
+	unsigned int i;
+
+	nct7802y_update(dev, FAN_ENABLE, 0, FANx_ENABLE(fan));
+
+	/* By default, do not map any temperature control to the fan. */
+	for (temp = 0; temp < NCT7802Y_FAN_CNT; ++temp) {
+		nct7802y_update(dev, TEMP_TO_FAN_MAP(temp),
+				TEMPx_TO_FANy_MAP(temp, fan), 0);
+	}
+
+	if (config->mode == FAN_MANUAL) {
+		nct7802y_write(dev, FAN_CTRL(fan), config->duty_cycle);
+	} else {
+		u8 set = 0, div, mul;
+		if (config->smart.mode == SMART_FAN_RPM) {
+			set |= CLOSE_LOOP_FANx_EN(fan);
+			div = 50;
+			if (config->smart.speed == FAN_SPPED_HIGHSPEED) {
+				set |= CLOSE_LOOP_FANx_HIGH_RPM(fan);
+				div = 100;
+			}
+			mul = 1;
+		} else {
+			/* SMART_FAN_DUTY is given in %, 100% == 255. */
+			div = 100;
+			mul = 255;
+		}
+		nct7802y_update(dev, CLOSE_LOOP_FAN_RPM_CTRL,
+				CLOSE_LOOP_FANx_EN(fan) |
+					CLOSE_LOOP_FANx_HIGH_RPM(fan),
+				set);
+
+		/* Map TEMPx to FANx to make things simple */
+		nct7802y_update(dev, TEMP_TO_FAN_MAP(fan),
+				TEMPx_TO_FAN_MAP_MASK(fan),
+				TEMPx_TO_FANy_MAP(fan, fan));
+
+		nct7802y_update(dev, FAN_CTRL_TEMP_SRC(fan),
+				FAN_CTRL_TEMPx_SRC_MASK(fan),
+				FAN_CTRL_TEMPx_SRCy(
+					fan, config->smart.tempsrc));
+
+		for (i = 0; i < ARRAY_SIZE(config->smart.table); ++i) {
+			nct7802y_write(dev, TABLEx_TEMP_POINTy(fan, i),
+				       config->smart.table[i].temp);
+			nct7802y_write(dev, TABLEx_TARGET_POINTy(fan, i),
+				(config->smart.table[i].target * mul) / div);
+		}
+		nct7802y_write(dev, TABLEx_TEMP_POINTy(fan, 4),
+			       config->smart.critical_temp);
+	}
+}
+
+void nct7802y_init_fan(struct device *const dev)
+{
+	const struct drivers_i2c_nct7802y_config *const config = dev->chip_info;
+	unsigned int i;
+	u8 set;
+
+	if (nct7802y_select_bank(dev, 0) != CB_SUCCESS)
+		return;
+
+	for (i = 0; i < NCT7802Y_FAN_CNT; ++i) {
+		if (config->fan[i].mode != FAN_IGNORE)
+			init_fan(dev, &config->fan[i], i);
+	}
+
+	switch (config->on_pecierror) {
+	case PECI_ERROR_KEEP:
+		set = CLOSE_LOOP_FAN_PECI_ERR_CURR;
+		break;
+	case PECI_ERROR_VALUE:
+		set = CLOSE_LOOP_FAN_PECI_ERR_VALUE;
+		break;
+	case PECI_ERROR_FULLSPEED:
+		set = CLOSE_LOOP_FAN_PECI_ERR_MAX;
+		break;
+	default:
+		set = 0;
+		break;
+	}
+	nct7802y_update(dev, CLOSE_LOOP_FAN_RPM_CTRL,
+			CLOSE_LOOP_FAN_PECI_ERR_MASK, set);
+	nct7802y_write(dev, FAN_DUTY_ON_PECI_ERROR, config->pecierror_minduty);
+}