staging: omap-thermal: common code to expose driver to thermal framework

This patch has the common thermal framework support for OMAP
bandgap driver. It includes the zone registration and unregistration,
the cpu cooling and the trip definitions.

The trips definition is essentially one trip for passive cooling
using the generic cpu cooling device and another one for thermal
shutdown. The cpu cooling device is built based on the existing
cpu freq table. The build should be agnostic to omap version,
but relies that cpufreq is up and running by the time the driver
registers the cpu cooling, as it relies on the table walk api
from cpufreq.

Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/omap-thermal/Kconfig

@@ -9,3 +9,12 @@ config OMAP_BANDGAP
 
 	  This includes alert interrupts generation and also the TSHUT
 	  support.
+
+config OMAP_THERMAL
+	bool "Texas Instruments OMAP4+ thermal framework support"
+	depends on OMAP_BANDGAP
+	depends on CPU_THERMAL
+	help
+	  If you say yes here you want to get support for generic thermal
+	  framework for the Texas Instruments OMAP4460+ on die bandgap
+	  temperature sensor.

drivers/staging/omap-thermal/Makefile

@@ -1,2 +1,3 @@
 obj-$(CONFIG_OMAP_BANDGAP)	+= omap-thermal.o
 omap-thermal-y			:= omap-bandgap.o
+omap-thermal-$(CONFIG_OMAP_THERMAL)	+= omap-thermal-common.o

drivers/staging/omap-thermal/omap-thermal-common.c

@@ -0,0 +1,364 @@
+/*
+ * OMAP thermal driver interface
+ *
+ * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
+ * Contact:
+ *   Eduardo Valentin <eduardo.valentin@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/gfp.h>
+#include <linux/kernel.h>
+#include <linux/workqueue.h>
+#include <linux/thermal.h>
+#include <linux/cpufreq.h>
+#include <linux/cpu_cooling.h>
+
+#include "omap-thermal.h"
+#include "omap-bandgap.h"
+
+/* common data structures */
+struct omap_thermal_data {
+	struct thermal_zone_device *omap_thermal;
+	struct thermal_cooling_device *cool_dev;
+	struct omap_bandgap *bg_ptr;
+	enum thermal_device_mode mode;
+	struct work_struct thermal_wq;
+	int sensor_id;
+};
+
+static void omap_thermal_work(struct work_struct *work)
+{
+	struct omap_thermal_data *data = container_of(work,
+					struct omap_thermal_data, thermal_wq);
+
+	thermal_zone_device_update(data->omap_thermal);
+
+	dev_dbg(&data->omap_thermal->device, "updated thermal zone %s\n",
+		data->omap_thermal->type);
+}
+
+/**
+ * omap_thermal_hotspot_temperature - returns sensor extrapolated temperature
+ * @t:	omap sensor temperature
+ * @s:	omap sensor slope value
+ * @c:	omap sensor const value
+ */
+static inline int omap_thermal_hotspot_temperature(int t, int s, int c)
+{
+	int delta = t * s / 1000 + c;
+
+	if (delta < 0)
+		delta = 0;
+
+	return t + delta;
+}
+
+/* thermal zone ops */
+/* Get temperature callback function for thermal zone*/
+static inline int omap_thermal_get_temp(struct thermal_zone_device *thermal,
+					 unsigned long *temp)
+{
+	struct omap_thermal_data *data = thermal->devdata;
+	struct omap_bandgap *bg_ptr = data->bg_ptr;
+	struct omap_temp_sensor *s = &bg_ptr->conf->sensors[data->sensor_id];
+	int ret, tmp, pcb_temp, slope, constant;
+
+	ret = omap_bandgap_read_temperature(bg_ptr, data->sensor_id, &tmp);
+	if (ret)
+		return ret;
+
+	pcb_temp = 0;
+	/* TODO: Introduce pcb temperature lookup */
+	/* In case pcb zone is available, use the extrapolation rule with it */
+	if (pcb_temp) {
+		tmp -= pcb_temp;
+		slope = s->slope_pcb;
+		constant = s->constant_pcb;
+	} else {
+		slope = s->slope;
+		constant = s->constant;
+	}
+	*temp = omap_thermal_hotspot_temperature(tmp, slope, constant);
+
+	return ret;
+}
+
+/* Bind callback functions for thermal zone */
+static int omap_thermal_bind(struct thermal_zone_device *thermal,
+			      struct thermal_cooling_device *cdev)
+{
+	struct omap_thermal_data *data = thermal->devdata;
+	int max, id;
+
+	if (IS_ERR_OR_NULL(data))
+		return -ENODEV;
+
+	/* check if this is the cooling device we registered */
+	if (data->cool_dev != cdev)
+		return 0;
+
+	id = data->sensor_id;
+	max = data->bg_ptr->conf->sensors[id].cooling_data.freq_clip_count;
+
+	/* TODO: bind with min and max states */
+	/* Simple thing, two trips, one passive another critical */
+	return thermal_zone_bind_cooling_device(thermal, 0, cdev);
+}
+
+/* Unbind callback functions for thermal zone */
+static int omap_thermal_unbind(struct thermal_zone_device *thermal,
+				struct thermal_cooling_device *cdev)
+{
+	struct omap_thermal_data *data = thermal->devdata;
+
+	if (IS_ERR_OR_NULL(data))
+		return -ENODEV;
+
+	/* check if this is the cooling device we registered */
+	if (data->cool_dev != cdev)
+		return 0;
+
+	/* Simple thing, two trips, one passive another critical */
+	return thermal_zone_unbind_cooling_device(thermal, 0, cdev);
+}
+
+/* Get mode callback functions for thermal zone */
+static int omap_thermal_get_mode(struct thermal_zone_device *thermal,
+				  enum thermal_device_mode *mode)
+{
+	struct omap_thermal_data *data = thermal->devdata;
+
+	if (data)
+		*mode = data->mode;
+
+	return 0;
+}
+
+/* Set mode callback functions for thermal zone */
+static int omap_thermal_set_mode(struct thermal_zone_device *thermal,
+				  enum thermal_device_mode mode)
+{
+	struct omap_thermal_data *data = thermal->devdata;
+
+	if (!data->omap_thermal) {
+		dev_notice(&thermal->device, "thermal zone not registered\n");
+		return 0;
+	}
+
+	mutex_lock(&data->omap_thermal->lock);
+
+	if (mode == THERMAL_DEVICE_ENABLED)
+		data->omap_thermal->polling_delay = FAST_TEMP_MONITORING_RATE;
+	else
+		data->omap_thermal->polling_delay = 0;
+
+	mutex_unlock(&data->omap_thermal->lock);
+
+	data->mode = mode;
+	thermal_zone_device_update(data->omap_thermal);
+	dev_dbg(&thermal->device, "thermal polling set for duration=%d msec\n",
+		data->omap_thermal->polling_delay);
+
+	return 0;
+}
+
+/* Get trip type callback functions for thermal zone */
+static int omap_thermal_get_trip_type(struct thermal_zone_device *thermal,
+				       int trip, enum thermal_trip_type *type)
+{
+	if (!omap_thermal_is_valid_trip(trip))
+		return -EINVAL;
+
+	if (trip + 1 == OMAP_TRIP_NUMBER)
+		*type = THERMAL_TRIP_CRITICAL;
+	else
+		*type = THERMAL_TRIP_PASSIVE;
+
+	return 0;
+}
+
+/* Get trip temperature callback functions for thermal zone */
+static int omap_thermal_get_trip_temp(struct thermal_zone_device *thermal,
+				       int trip, unsigned long *temp)
+{
+	if (!omap_thermal_is_valid_trip(trip))
+		return -EINVAL;
+
+	*temp = omap_thermal_get_trip_value(trip);
+
+	return 0;
+}
+
+/* Get critical temperature callback functions for thermal zone */
+static int omap_thermal_get_crit_temp(struct thermal_zone_device *thermal,
+				       unsigned long *temp)
+{
+	/* shutdown zone */
+	return omap_thermal_get_trip_temp(thermal, OMAP_TRIP_NUMBER - 1, temp);
+}
+
+static struct thermal_zone_device_ops omap_thermal_ops = {
+	.get_temp = omap_thermal_get_temp,
+	/* TODO: add .get_trend */
+	.bind = omap_thermal_bind,
+	.unbind = omap_thermal_unbind,
+	.get_mode = omap_thermal_get_mode,
+	.set_mode = omap_thermal_set_mode,
+	.get_trip_type = omap_thermal_get_trip_type,
+	.get_trip_temp = omap_thermal_get_trip_temp,
+	.get_crit_temp = omap_thermal_get_crit_temp,
+};
+
+int omap_thermal_expose_sensor(struct omap_bandgap *bg_ptr, int id,
+			       char *domain)
+{
+	struct omap_thermal_data *data;
+
+	data = devm_kzalloc(bg_ptr->dev, sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		dev_err(bg_ptr->dev, "kzalloc fail\n");
+		return -ENOMEM;
+	}
+	data->sensor_id = id;
+	data->bg_ptr = bg_ptr;
+	data->mode = THERMAL_DEVICE_ENABLED;
+	INIT_WORK(&data->thermal_wq, omap_thermal_work);
+
+	/* TODO: remove TC1 TC2 */
+	/* Create thermal zone */
+	data->omap_thermal = thermal_zone_device_register(domain,
+				OMAP_TRIP_NUMBER, 0, data, &omap_thermal_ops,
+				0, FAST_TEMP_MONITORING_RATE, 0, 0);
+	if (IS_ERR_OR_NULL(data->omap_thermal)) {
+		dev_err(bg_ptr->dev, "thermal zone device is NULL\n");
+		return PTR_ERR(data->omap_thermal);
+	}
+	data->omap_thermal->polling_delay = FAST_TEMP_MONITORING_RATE;
+	omap_bandgap_set_sensor_data(bg_ptr, id, data);
+
+	return 0;
+}
+
+int omap_thermal_remove_sensor(struct omap_bandgap *bg_ptr, int id)
+{
+	struct omap_thermal_data *data;
+
+	data = omap_bandgap_get_sensor_data(bg_ptr, id);
+
+	thermal_zone_device_unregister(data->omap_thermal);
+
+	return 0;
+}
+
+int omap_thermal_report_sensor_temperature(struct omap_bandgap *bg_ptr, int id)
+{
+	struct omap_thermal_data *data;
+
+	data = omap_bandgap_get_sensor_data(bg_ptr, id);
+
+	schedule_work(&data->thermal_wq);
+
+	return 0;
+}
+
+static int omap_thermal_build_cpufreq_clip(struct omap_bandgap *bg_ptr,
+					   struct freq_clip_table **tab_ptr,
+					   int *tab_size)
+{
+	struct cpufreq_frequency_table *freq_table;
+	struct freq_clip_table *tab;
+	int i, count = 0;
+
+	freq_table = cpufreq_frequency_get_table(0);
+	if (IS_ERR_OR_NULL(freq_table)) {
+		dev_err(bg_ptr->dev,
+			"%s: failed to get cpufreq table (%p)\n",
+			__func__, freq_table);
+		return -EINVAL;
+	}
+
+	for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
+		unsigned int freq = freq_table[i].frequency;
+		if (freq == CPUFREQ_ENTRY_INVALID)
+			continue;
+		count++;
+	}
+
+	tab = devm_kzalloc(bg_ptr->dev, sizeof(*tab) * count, GFP_KERNEL);
+	if (!tab) {
+		dev_err(bg_ptr->dev,
+			"%s: no memory available\n", __func__);
+		return -ENOMEM;
+	}
+
+	for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
+		unsigned int freq = freq_table[i].frequency;
+
+		if (freq == CPUFREQ_ENTRY_INVALID)
+			continue;
+
+		tab[count - i - 1].freq_clip_max = freq;
+		tab[count - i - 1].temp_level = OMAP_TRIP_HOT;
+		tab[count - i - 1].mask_val = cpumask_of(0);
+	}
+
+	*tab_ptr = tab;
+	*tab_size = count;
+
+	return 0;
+}
+
+int omap_thermal_register_cpu_cooling(struct omap_bandgap *bg_ptr, int id)
+{
+	struct omap_thermal_data *data;
+	struct freq_clip_table *tab_ptr;
+	int tab_size, ret;
+
+	data = omap_bandgap_get_sensor_data(bg_ptr, id);
+
+	ret = omap_thermal_build_cpufreq_clip(bg_ptr, &tab_ptr, &tab_size);
+	if (ret < 0) {
+		dev_err(bg_ptr->dev,
+			"%s: failed to build cpufreq clip table\n", __func__);
+		return ret;
+	}
+
+	/* Register cooling device */
+	data->cool_dev = cpufreq_cooling_register(tab_ptr, tab_size);
+	if (IS_ERR_OR_NULL(data->cool_dev)) {
+		dev_err(bg_ptr->dev,
+			"Failed to register cpufreq cooling device\n");
+		return PTR_ERR(data->cool_dev);
+	}
+	bg_ptr->conf->sensors[id].cooling_data.freq_clip_count = tab_size;
+
+	return 0;
+}
+
+int omap_thermal_unregister_cpu_cooling(struct omap_bandgap *bg_ptr, int id)
+{
+	struct omap_thermal_data *data;
+
+	data = omap_bandgap_get_sensor_data(bg_ptr, id);
+	cpufreq_cooling_unregister(data->cool_dev);
+
+	return 0;
+}