drivers/i2c/lm96000: Add new hardware-monitoring IC

LM96000 is the successor of the famous LM85.

Change-Id: Ie7df3107bffb7f8e45e71c4c1fbe4eb0a9e3cd03
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/21194
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
diff --git a/src/drivers/i2c/lm96000/lm96000.c b/src/drivers/i2c/lm96000/lm96000.c
new file mode 100644
index 0000000..4bb2a4a
--- /dev/null
+++ b/src/drivers/i2c/lm96000/lm96000.c
@@ -0,0 +1,226 @@
+/*
+ * 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 <delay.h>
+#include <timer.h>
+#include <console/console.h>
+#include <device/device.h>
+#include <device/i2c_bus.h>
+
+#include "lm96000.h"
+#include "chip.h"
+
+static inline int lm96000_read(struct device *const dev, const u8 reg)
+{
+	return i2c_dev_readb_at(dev, reg);
+}
+
+static inline int lm96000_write(struct device *const dev,
+				const u8 reg, const u8 value)
+{
+	return i2c_dev_writeb_at(dev, reg, value);
+}
+
+static inline int lm96000_update(struct device *const dev, const u8 reg,
+				 const u8 clear_mask, const u8 set_mask)
+{
+	const int val = i2c_dev_readb_at(dev, reg);
+	if (val < 0)
+		return val;
+	return i2c_dev_writeb_at(dev, reg, (val & ~clear_mask) | set_mask);
+}
+
+static const unsigned int ref_mv[] = { 2500, 2250, 3300, 5000, 12000 };
+
+static u8 lm96000_to_low_limit(const enum lm96000_vin ref, const u16 limit)
+{
+	const unsigned int reg =
+		(unsigned int)limit * 0xc0 / ref_mv[ref];
+	return reg < 0xff ? reg : 0xff;
+}
+
+static u8 lm96000_to_high_limit(const enum lm96000_vin ref, const u16 limit)
+{
+	const unsigned int reg =
+		DIV_ROUND_UP((unsigned int)limit * 0xc0, ref_mv[ref]);
+	return reg < 0xff ? reg : 0xff;
+}
+
+static void lm96000_set_vin_limits(struct device *const dev,
+		const struct drivers_i2c_lm96000_config *const config)
+{
+	unsigned int i;
+
+	for (i = 0; i < LM96000_VIN_CNT; ++i) {
+		lm96000_write(dev, LM96000_VIN_LOW_LIMIT(i),
+			      lm96000_to_low_limit(i, config->vin[i].low));
+		if (config->vin[i].high > config->vin[i].low)
+			lm96000_write(dev, LM96000_VIN_HIGH_LIMIT(i),
+				lm96000_to_high_limit(i, config->vin[i].high));
+		else
+			lm96000_write(dev, LM96000_VIN_HIGH_LIMIT(i), 0xff);
+	}
+}
+
+static void lm96000_set_temp_limits(struct device *const dev,
+		const struct drivers_i2c_lm96000_config *const config)
+{
+	unsigned int i;
+
+	for (i = 0; i < LM96000_TEMP_IN_CNT; ++i) {
+		lm96000_write(dev, LM96000_TEMP_LOW_LIMIT(i),
+			      config->temp_in[i].low);
+		if (config->temp_in[i].high > config->temp_in[i].low)
+			lm96000_write(dev, LM96000_TEMP_HIGH_LIMIT(i),
+				      config->temp_in[i].high);
+		else
+			lm96000_write(dev, LM96000_TEMP_HIGH_LIMIT(i), 0x7f);
+	}
+}
+
+static u16 lm96000_rpm_to_tach(const u16 rpm)
+{
+	return rpm ? (60 * 90000 / rpm) & 0xfffc : 0xfffc;
+}
+
+static void lm96000_set_fan_limits(struct device *const dev,
+		const struct drivers_i2c_lm96000_config *const config)
+{
+	unsigned int i;
+
+	for (i = 0; i < LM96000_FAN_IN_CNT; ++i) {
+		const u16 tach = lm96000_rpm_to_tach(config->fan_in[i].low);
+		lm96000_write(dev, LM96000_FAN_LOW_LIMIT(i), tach & 0xff);
+		lm96000_write(dev, LM96000_FAN_LOW_LIMIT(i) + 1, tach >> 8);
+	}
+}
+
+static u8 lm96000_to_duty(const u8 duty_cycle)
+{
+	return duty_cycle * 255 / 100;
+}
+
+static void lm96000_configure_pwm(struct device *const dev,
+				  const unsigned int fan,
+				  const struct lm96000_fan_config *const config)
+{
+	lm96000_update(dev, LM96000_FAN_CFG(fan),
+		       LM96000_FAN_CFG_MODE_MASK | LM96000_FAN_CFG_PWM_INVERT |
+		       LM96000_FAN_CFG_SPINUP_MASK,
+		       ((config->mode << LM96000_FAN_CFG_MODE_SHIFT)
+			& LM96000_FAN_CFG_MODE_MASK) |
+		       (config->invert ? LM96000_FAN_CFG_PWM_INVERT : 0) |
+		       config->spinup);
+	lm96000_update(dev, LM96000_FAN_FREQ(fan),
+		       LM96000_FAN_FREQ_MASK, config->freq);
+	lm96000_update(dev, LM96000_TACH_MONITOR_MODE,
+		       LM96000_TACH_MODE_FAN_MASK(fan),
+		       config->freq <= LM96000_PWM_94HZ
+		       ? config->tach << LM96000_TACH_MODE_FAN_SHIFT(fan) : 0);
+
+	switch (config->mode) {
+	case LM96000_FAN_ZONE_1_AUTO:
+	case LM96000_FAN_ZONE_2_AUTO:
+	case LM96000_FAN_ZONE_3_AUTO:
+	case LM96000_FAN_HOTTEST_23:
+	case LM96000_FAN_HOTTEST_123:
+		lm96000_write(dev, LM96000_FAN_MIN_PWM(fan),
+			      lm96000_to_duty(config->min_duty));
+		break;
+	case LM96000_FAN_MANUAL:
+		lm96000_write(dev, LM96000_FAN_DUTY(fan),
+			      lm96000_to_duty(config->duty_cycle));
+		break;
+	default:
+		break;
+	}
+}
+
+static void lm96000_configure_temp_zone(struct device *const dev,
+		const unsigned int zone,
+		const struct lm96000_temp_zone *const config)
+{
+	static const u8 temp_range[] =
+		{ 2, 3, 3, 4, 5, 7, 8, 10, 13, 16, 20, 27, 32, 40, 53, 80 };
+	unsigned int i;
+
+	/* find longest range that starts from 25°C */
+	for (i = ARRAY_SIZE(temp_range) - 1; i > 0; --i) {
+		if (temp_range[i] + 25 <= config->target_temp)
+			break;
+	}
+
+	lm96000_update(dev, LM96000_ZONE_RANGE(zone),
+		       LM96000_ZONE_RANGE_MASK, i << LM96000_ZONE_RANGE_SHIFT);
+	lm96000_write(dev, LM96000_ZONE_TEMP_LOW(zone),
+		      config->target_temp >= temp_range[i]
+		      ? config->target_temp - temp_range[i]
+		      : 0);
+	lm96000_write(dev, LM96000_ZONE_TEMP_PANIC(zone),
+		      config->panic_temp ? config->panic_temp : 100);
+	lm96000_update(dev, LM96000_FAN_MIN_OFF,
+		       LM96000_FAN_MIN(zone),
+		       config->min_off ? LM96000_FAN_MIN(zone) : 0);
+}
+
+static void lm96000_init(struct device *const dev)
+{
+	const struct drivers_i2c_lm96000_config *const config = dev->chip_info;
+	unsigned int i, lm_config;
+	struct stopwatch sw;
+
+	printk(BIOS_DEBUG, "lm96000: Initialization hardware monitoring.\n");
+
+	stopwatch_init_msecs_expire(&sw, 1000);
+	lm_config = lm96000_read(dev, LM96000_CONFIG);
+	while ((lm_config < 0 || !(lm_config & LM96000_READY))) {
+		mdelay(1);
+		lm_config = lm96000_read(dev, LM96000_CONFIG);
+		if (stopwatch_expired(&sw))
+			break;
+	}
+	if (lm_config < 0 || !(lm_config & LM96000_READY)) {
+		printk(BIOS_INFO, "lm96000: Not ready after 1s.\n");
+		return;
+	}
+
+	lm96000_set_vin_limits(dev, config);
+	lm96000_set_temp_limits(dev, config);
+	lm96000_set_fan_limits(dev, config);
+	for (i = 0; i < LM96000_PWM_CTL_CNT; ++i) {
+		if (config->fan[i].mode != LM96000_FAN_IGNORE)
+			lm96000_configure_pwm(dev, i, config->fan + i);
+	}
+	for (i = 0; i < LM96000_TEMP_ZONE_CNT; ++i)
+		lm96000_configure_temp_zone(dev, i, config->zone + i);
+	lm96000_update(dev, LM96000_CONFIG, 0, LM96000_START);
+}
+
+static struct device_operations lm96000_ops = {
+	.read_resources		= DEVICE_NOOP,
+	.set_resources		= DEVICE_NOOP,
+	.enable_resources	= DEVICE_NOOP,
+	.init			= lm96000_init,
+};
+
+static void lm96000_enable(struct device *const dev)
+{
+	dev->ops = &lm96000_ops;
+}
+
+struct chip_operations drivers_i2c_lm96000_ops = {
+	CHIP_NAME("LM96000")
+	.enable_dev = lm96000_enable
+};