Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753504AbcDYDDW (ORCPT ); Sun, 24 Apr 2016 23:03:22 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:33694 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751781AbcDYDDT (ORCPT ); Sun, 24 Apr 2016 23:03:19 -0400 From: Caesar Wang To: edubezval@gmail.com Cc: Heiko Stuebner , dianders@chromium.org, briannorris@google.com, smbarber@google.com, linux-rockchip@lists.infradead.org, dmitry.torokhov@gmail.com, huangtao@rock-chips.com, eddie.cai@rock-chips.com, Sascha Hauer , Caesar Wang , Zhang Rui , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/4] thermal: Add support for hardware-tracked trip points Date: Mon, 25 Apr 2016 11:02:44 +0800 Message-Id: <1461553367-24744-2-git-send-email-wxt@rock-chips.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1461553367-24744-1-git-send-email-wxt@rock-chips.com> References: <1461553367-24744-1-git-send-email-wxt@rock-chips.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4240 Lines: 136 From: Sascha Hauer This adds support for hardware-tracked trip points to the device tree thermal sensor framework. The framework supports an arbitrary number of trip points. Whenever the current temperature is updated, the trip points immediately below and above the current temperature are found. A .set_trips callback is then called with the temperatures. If there is no trip point above or below the current temperature, the passed trip temperature will be -INT_MAX or INT_MAX respectively. In this callback, the driver should program the hardware such that it is notified when either of these trip points are triggered. When a trip point is triggered, the driver should call `thermal_zone_device_update' for the respective thermal zone. This will cause the trip points to be updated again. If .set_trips is not implemented, the framework behaves as before. This patch is based on an earlier version from Mikko Perttunen Signed-off-by: Sascha Hauer Signed-off-by: Caesar Wang Cc: Zhang Rui Cc: Eduardo Valentin Cc: linux-pm@vger.kernel.org --- drivers/thermal/thermal_core.c | 48 ++++++++++++++++++++++++++++++++++++++++++ include/linux/thermal.h | 3 +++ 2 files changed, 51 insertions(+) diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index f1db496..cfef8cc 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -520,6 +520,47 @@ exit: } EXPORT_SYMBOL_GPL(thermal_zone_get_temp); +static void thermal_zone_set_trips(struct thermal_zone_device *tz) +{ + int low = -INT_MAX; + int high = INT_MAX; + int trip_temp, hysteresis; + int temp = tz->temperature; + int i, ret; + + if (!tz->ops->set_trips) + return; + + for (i = 0; i < tz->trips; i++) { + int trip_low; + + tz->ops->get_trip_temp(tz, i, &trip_temp); + tz->ops->get_trip_hyst(tz, i, &hysteresis); + + trip_low = trip_temp - hysteresis; + + if (trip_low < temp && trip_low > low) + low = trip_low; + + if (trip_temp > temp && trip_temp < high) + high = trip_temp; + } + + /* No need to change trip points */ + if (tz->prev_low_trip == low && tz->prev_high_trip == high) + return; + + tz->prev_low_trip = low; + tz->prev_high_trip = high; + + dev_dbg(&tz->device, "new temperature boundaries: %d < x < %d\n", + low, high); + + ret = tz->ops->set_trips(tz, low, high); + if (ret) + dev_err(&tz->device, "Failed to set trips: %d\n", ret); +} + static void update_temperature(struct thermal_zone_device *tz) { int temp, ret; @@ -569,6 +610,8 @@ void thermal_zone_device_update(struct thermal_zone_device *tz) update_temperature(tz); + thermal_zone_set_trips(tz); + for (count = 0; count < tz->trips; count++) handle_thermal_trip(tz, count); } @@ -754,6 +797,9 @@ trip_point_hyst_store(struct device *dev, struct device_attribute *attr, */ ret = tz->ops->set_trip_hyst(tz, trip, temperature); + if (!ret) + thermal_zone_set_trips(tz); + return ret ? ret : count; } @@ -1843,6 +1889,8 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type, tz->trips = trips; tz->passive_delay = passive_delay; tz->polling_delay = polling_delay; + tz->prev_low_trip = INT_MAX; + tz->prev_high_trip = -INT_MAX; /* A new thermal zone needs to be updated anyway. */ atomic_set(&tz->need_update, 1); diff --git a/include/linux/thermal.h b/include/linux/thermal.h index e45abe7..e258359 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -98,6 +98,7 @@ struct thermal_zone_device_ops { int (*unbind) (struct thermal_zone_device *, struct thermal_cooling_device *); int (*get_temp) (struct thermal_zone_device *, int *); + int (*set_trips) (struct thermal_zone_device *, int, int); int (*get_mode) (struct thermal_zone_device *, enum thermal_device_mode *); int (*set_mode) (struct thermal_zone_device *, @@ -199,6 +200,8 @@ struct thermal_zone_device { int last_temperature; int emul_temperature; int passive; + int prev_low_trip; + int prev_high_trip; unsigned int forced_passive; atomic_t need_update; struct thermal_zone_device_ops *ops; -- 1.9.1