drm/nouveau/fan: add toggle fan support

v2: change percent from int to atomic_t
v3: random fixes
v4 (Ben Skeggs):
- adapted for split-out fan-control "protocol" structure
- removed need for timer resched
- support for forcing 'toggle' control on PWM boards

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Martin Peres <martin.peres@labri.fr>

drivers/gpu/drm/nouveau/Makefile

@@ -108,6 +108,7 @@ nouveau-y += core/subdev/therm/base.o
 nouveau-y += core/subdev/therm/fan.o
 nouveau-y += core/subdev/therm/fannil.o
 nouveau-y += core/subdev/therm/fanpwm.o
+nouveau-y += core/subdev/therm/fantog.o
 nouveau-y += core/subdev/therm/ic.o
 nouveau-y += core/subdev/therm/temp.o
 nouveau-y += core/subdev/therm/nv40.o

drivers/gpu/drm/nouveau/core/include/subdev/timer.h

@@ -10,6 +10,14 @@ struct nouveau_alarm {
 	void (*func)(struct nouveau_alarm *);
 };
 
+static inline void
+nouveau_alarm_init(struct nouveau_alarm *alarm,
+		   void (*func)(struct nouveau_alarm *))
+{
+	INIT_LIST_HEAD(&alarm->head);
+	alarm->func = func;
+}
+
 bool nouveau_timer_wait_eq(void *, u64 nsec, u32 addr, u32 mask, u32 data);
 bool nouveau_timer_wait_ne(void *, u64 nsec, u32 addr, u32 mask, u32 data);
 bool nouveau_timer_wait_cb(void *, u64 nsec, bool (*func)(void *), void *data);

drivers/gpu/drm/nouveau/core/subdev/therm/fan.c

@@ -149,7 +149,6 @@ nouveau_therm_fan_set_defaults(struct nouveau_therm *therm)
 	priv->fan->bios.max_duty = 100;
 }
 
-
 static void
 nouveau_therm_fan_safety_checks(struct nouveau_therm *therm)
 {
@@ -164,11 +163,6 @@ nouveau_therm_fan_safety_checks(struct nouveau_therm *therm)
 		priv->fan->bios.min_duty = priv->fan->bios.max_duty;
 }
 
-int nouveau_fan_pwm_clock_dummy(struct nouveau_therm *therm)
-{
-	return 1;
-}
-
 int
 nouveau_therm_fan_ctor(struct nouveau_therm *therm)
 {
@@ -182,7 +176,9 @@ nouveau_therm_fan_ctor(struct nouveau_therm *therm)
 	ret = gpio->find(gpio, 0, DCB_GPIO_PWM_FAN, 0xff, &func);
 	if (ret == 0)
 		ret = nouveau_fanpwm_create(therm, &func);
-	if (ret)
+	if (ret != 0)
+		ret = nouveau_fantog_create(therm, &func);
+	if (ret != 0)
 		ret = nouveau_fannil_create(therm);
 	if (ret)
 		return ret;
@@ -202,6 +198,5 @@ nouveau_therm_fan_ctor(struct nouveau_therm *therm)
 	nouveau_therm_fan_safety_checks(therm);
 
 	nouveau_therm_fan_set_mode(therm, FAN_CONTROL_NONE);
-
 	return 0;
 }

drivers/gpu/drm/nouveau/core/subdev/therm/fantog.c

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2012 The Nouveau community
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Martin Peres
+ */
+
+#include "priv.h"
+
+#include <core/object.h>
+#include <core/device.h>
+
+#include <subdev/gpio.h>
+#include <subdev/timer.h>
+
+struct nouveau_fantog_priv {
+	struct nouveau_fan base;
+	struct nouveau_therm *parent;
+	struct nouveau_alarm alarm;
+	spinlock_t lock;
+	u32 period_us;
+	u32 percent;
+	struct dcb_gpio_func func;
+};
+
+static void
+nouveau_fantog_update(struct nouveau_fantog_priv *priv, int percent)
+{
+	struct nouveau_therm_priv *tpriv = (void *)priv->parent;
+	struct nouveau_timer *ptimer = nouveau_timer(tpriv);
+	struct nouveau_gpio *gpio = nouveau_gpio(tpriv);
+	unsigned long flags;
+	int duty;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (percent < 0)
+		percent = priv->percent;
+	priv->percent = percent;
+
+	duty = !gpio->get(gpio, 0, DCB_GPIO_PWM_FAN, 0xff);
+	gpio->set(gpio, 0, DCB_GPIO_PWM_FAN, 0xff, duty);
+
+	if (list_empty(&priv->alarm.head) && percent != (duty * 100)) {
+		u64 next_change = (percent * priv->period_us) / 100;
+		if (!duty)
+			next_change = priv->period_us - next_change;
+		ptimer->alarm(ptimer, next_change * 1000, &priv->alarm);
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static void
+nouveau_fantog_alarm(struct nouveau_alarm *alarm)
+{
+	struct nouveau_fantog_priv *priv =
+	       container_of(alarm, struct nouveau_fantog_priv, alarm);
+	nouveau_fantog_update(priv, -1);
+}
+
+static int
+nouveau_fantog_get(struct nouveau_therm *therm)
+{
+	struct nouveau_therm_priv *tpriv = (void *)therm;
+	struct nouveau_fantog_priv *priv = (void *)tpriv->fan;
+	return priv->percent;
+}
+
+int
+nouveau_fantog_set(struct nouveau_therm *therm, int percent)
+{
+	struct nouveau_therm_priv *tpriv = (void *)therm;
+	struct nouveau_fantog_priv *priv = (void *)tpriv->fan;
+	if (therm->pwm_ctrl)
+		therm->pwm_ctrl(therm, priv->func.line, false);
+	nouveau_fantog_update(priv, percent);
+	return 0;
+}
+
+int
+nouveau_fantog_create(struct nouveau_therm *therm, struct dcb_gpio_func *func)
+{
+	struct nouveau_therm_priv *tpriv = (void *)therm;
+	struct nouveau_fantog_priv *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	tpriv->fan = &priv->base;
+	if (!priv)
+		return -ENOMEM;
+
+	priv->parent = therm;
+	priv->base.type = "toggle";
+	priv->base.get = nouveau_fantog_get;
+	priv->base.set = nouveau_fantog_set;
+	nouveau_alarm_init(&priv->alarm, nouveau_fantog_alarm);
+	priv->period_us = 100000; /* 10Hz */
+	priv->percent = 100;
+	priv->func = *func;
+	spin_lock_init(&priv->lock);
+	return 0;
+}

drivers/gpu/drm/nouveau/core/subdev/therm/priv.h

@@ -31,6 +31,7 @@
 #include <subdev/bios/gpio.h>
 #include <subdev/bios/perf.h>
 #include <subdev/bios/therm.h>
+#include <subdev/timer.h>
 
 struct nouveau_fan {
 	const char *type;
@@ -89,6 +90,7 @@ int nv50_temp_get(struct nouveau_therm *therm);
 int nva3_therm_fan_sense(struct nouveau_therm *);
 
 int nouveau_fanpwm_create(struct nouveau_therm *, struct dcb_gpio_func *);
+int nouveau_fantog_create(struct nouveau_therm *, struct dcb_gpio_func *);
 int nouveau_fannil_create(struct nouveau_therm *);
 
 #endif

drivers/gpu/drm/nouveau/core/subdev/timer/nv04.c

@@ -79,7 +79,7 @@ nv04_timer_alarm_trigger(struct nouveau_timer *ptimer)
 
 	/* execute any pending alarm handlers */
 	list_for_each_entry_safe(alarm, atemp, &exec, head) {
-		list_del(&alarm->head);
+		list_del_init(&alarm->head);
 		alarm->func(alarm);
 	}
 }