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https://github.com/Telecominfraproject/OpenCellular.git
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41cde66516
The fans on samus have a recommended minimum duty cycle of 20% while running, but 30% in order to start. We've been using the EC's built-in fan controller for the start requirement, but it has a minimum fast-start duty cycle of 50%. It turns out that that speed is noticeably noisy. This change handles the startup with logic in the EC instead, so that the fan only tries to spin at 30% initially (or if it drops too much below the minimum turning speed). BUG=chrome-os-partner:33429 BRANCH=ToT,samus TEST=make buildall -j Boot the system, let it idle with the browser windows closed, the browse a bit, then idle. Listen for changes to the fans. Before, I could hear the fans kick in and out as the AP load changed. Now it's much quieter. Change-Id: Id35215520c064eb6843686ec8bb5f3618dac6cf6 Signed-off-by: Bill Richardson <wfrichar@chromium.org> Reviewed-on: https://chromium-review.googlesource.com/227658 Reviewed-by: Randall Spangler <rspangler@chromium.org>
94 lines
2.7 KiB
C
94 lines
2.7 KiB
C
/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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/* Fan control module for Chrome EC */
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#ifndef __CROS_EC_FAN_H
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#define __CROS_EC_FAN_H
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/* Characteristic of each physical fan */
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struct fan_t {
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unsigned int flags;
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/* rpm_min is to keep turning. rpm_start is to begin turning */
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int rpm_min;
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int rpm_start;
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int rpm_max;
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/* Hardware channel number (the meaning is chip-specific) */
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int ch;
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/* Active-high power_good input GPIO, or -1 if none */
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int pgood_gpio;
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/* Active-high power_enable output GPIO, or -1 if none */
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int enable_gpio;
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};
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/* Values for .flags field */
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/* Enable automatic RPM control using tach input */
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#define FAN_USE_RPM_MODE (1 << 0)
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/* Require a higher duty cycle to start up than to keep running */
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#define FAN_USE_FAST_START (1 << 1)
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/* The list of fans is instantiated in board.c. */
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extern const struct fan_t fans[];
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/**
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* Set the amount of active cooling needed. The thermal control task will call
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* this frequently, and the fan control logic will attempt to provide it.
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*
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* @param fan Fan number (index into fans[])
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* @param pct Percentage of cooling effort needed (0 - 100)
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*/
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void fan_set_percent_needed(int fan, int pct);
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/**
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* This function translates the percentage of cooling needed into a target RPM.
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* The default implementation should be sufficient for most needs, but
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* individual boards may provide a custom version if needed (see config.h).
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*
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* @param fan Fan number (index into fans[])
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* @param pct Percentage of cooling effort needed (always in [0,100])
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* Return Target RPM for fan
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*/
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int fan_percent_to_rpm(int fan, int pct);
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/**
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* These functions require chip-specific implementations.
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*/
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/* Enable/Disable the fan controller */
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void fan_set_enabled(int ch, int enabled);
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int fan_get_enabled(int ch);
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/* Fixed pwm duty cycle (0-100%) */
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void fan_set_duty(int ch, int percent);
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int fan_get_duty(int ch);
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/* Enable/Disable automatic RPM control using tach feedback */
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void fan_set_rpm_mode(int ch, int rpm_mode);
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int fan_get_rpm_mode(int ch);
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/* Set the target for the automatic RPM control */
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void fan_set_rpm_target(int ch, int rpm);
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int fan_get_rpm_actual(int ch);
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int fan_get_rpm_target(int ch);
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/* Is the fan stalled when it shouldn't be? */
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int fan_is_stalled(int ch);
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/* How is the automatic RPM control doing? */
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enum fan_status {
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FAN_STATUS_STOPPED = 0,
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FAN_STATUS_CHANGING = 1,
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FAN_STATUS_LOCKED = 2,
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FAN_STATUS_FRUSTRATED = 3
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};
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enum fan_status fan_get_status(int ch);
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/* Initialize the HW according to the desired flags */
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void fan_channel_setup(int ch, unsigned int flags);
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#endif /* __CROS_EC_FAN_H */
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