thermal: rcar: add interrupt support

This patch adds interrupt support for R-Car thermal driver.

New generation R-Car thermal sensor interrupt controller was
different from old generation.
This patch supports new generation sensor only,
since the old generation interrupt controller had never been used before,
and will never be used in the future.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers/thermal/rcar_thermal.c

@@ -19,6 +19,8 @@
  */
 #include <linux/delay.h>
 #include <linux/err.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
@@ -29,8 +31,15 @@
 
 #define IDLE_INTERVAL	5000
 
+#define COMMON_STR	0x00
+#define COMMON_ENR	0x04
+#define COMMON_INTMSK	0x0c
+
+#define REG_POSNEG	0x20
+#define REG_FILONOFF	0x28
 #define REG_THSCR	0x2c
 #define REG_THSSR	0x30
+#define REG_INTCTRL	0x34
 
 /* THSCR */
 #define CPCTL	(1 << 12)
@@ -42,14 +51,18 @@ struct rcar_thermal_common {
 	void __iomem *base;
 	struct device *dev;
 	struct list_head head;
+	spinlock_t lock;
 };
 
 struct rcar_thermal_priv {
 	void __iomem *base;
 	struct rcar_thermal_common *common;
 	struct thermal_zone_device *zone;
+	struct delayed_work work;
 	struct mutex lock;
 	struct list_head list;
+	int id;
+	int ctemp;
 };
 
 #define rcar_thermal_for_each_priv(pos, common)	\
@@ -59,11 +72,17 @@ struct rcar_thermal_priv {
 #define rcar_zone_to_priv(zone)		((zone)->devdata)
 #define rcar_priv_to_dev(priv)		((priv)->common->dev)
 #define rcar_has_irq_support(priv)	((priv)->common->base)
+#define rcar_id_to_shift(priv)		((priv)->id * 8)
+
+#ifdef DEBUG
+# define rcar_force_update_temp(priv)	1
+#else
+# define rcar_force_update_temp(priv)	0
+#endif
 
 /*
  *		basic functions
  */
-#if 0
 #define rcar_thermal_common_read(c, r) \
 	_rcar_thermal_common_read(c, COMMON_ ##r)
 static u32 _rcar_thermal_common_read(struct rcar_thermal_common *common,
@@ -92,7 +111,6 @@ static void _rcar_thermal_common_bset(struct rcar_thermal_common *common,
 	val |= (data & mask);
 	iowrite32(val, common->base + reg);
 }
-#endif
 
 #define rcar_thermal_read(p, r) _rcar_thermal_read(p, REG_ ##r)
 static u32 _rcar_thermal_read(struct rcar_thermal_priv *priv, u32 reg)
@@ -100,14 +118,12 @@ static u32 _rcar_thermal_read(struct rcar_thermal_priv *priv, u32 reg)
 	return ioread32(priv->base + reg);
 }
 
-#if 0 /* no user at this point */
 #define rcar_thermal_write(p, r, d) _rcar_thermal_write(p, REG_ ##r, d)
 static void _rcar_thermal_write(struct rcar_thermal_priv *priv,
 				u32 reg, u32 data)
 {
 	iowrite32(data, priv->base + reg);
 }
-#endif
 
 #define rcar_thermal_bset(p, r, m, d) _rcar_thermal_bset(p, REG_ ##r, m, d)
 static void _rcar_thermal_bset(struct rcar_thermal_priv *priv, u32 reg,
@@ -124,10 +140,8 @@ static void _rcar_thermal_bset(struct rcar_thermal_priv *priv, u32 reg,
 /*
  *		zone device functions
  */
-static int rcar_thermal_get_temp(struct thermal_zone_device *zone,
-			   unsigned long *temp)
+static int rcar_thermal_update_temp(struct rcar_thermal_priv *priv)
 {
-	struct rcar_thermal_priv *priv = rcar_zone_to_priv(zone);
 	struct device *dev = rcar_priv_to_dev(priv);
 	int i;
 	int ctemp, old, new;
@@ -163,8 +177,37 @@ static int rcar_thermal_get_temp(struct thermal_zone_device *zone,
 		return -EINVAL;
 	}
 
-	*temp = MCELSIUS((ctemp * 5) - 65);
+	/*
+	 * enable IRQ
+	 */
+	if (rcar_has_irq_support(priv)) {
+		rcar_thermal_write(priv, FILONOFF, 0);
+
+		/* enable Rising/Falling edge interrupt */
+		rcar_thermal_write(priv, POSNEG,  0x1);
+		rcar_thermal_write(priv, INTCTRL, (((ctemp - 0) << 8) |
+						   ((ctemp - 1) << 0)));
+	}
+
+	dev_dbg(dev, "thermal%d  %d -> %d\n", priv->id, priv->ctemp, ctemp);
+
+	priv->ctemp = ctemp;
+
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
 
+static int rcar_thermal_get_temp(struct thermal_zone_device *zone,
+				 unsigned long *temp)
+{
+	struct rcar_thermal_priv *priv = rcar_zone_to_priv(zone);
+
+	if (!rcar_has_irq_support(priv) || rcar_force_update_temp(priv))
+		rcar_thermal_update_temp(priv);
+
+	mutex_lock(&priv->lock);
+	*temp =  MCELSIUS((priv->ctemp * 5) - 65);
 	mutex_unlock(&priv->lock);
 
 	return 0;
@@ -234,6 +277,82 @@ static struct thermal_zone_device_ops rcar_thermal_zone_ops = {
 	.notify		= rcar_thermal_notify,
 };
 
+/*
+ *		interrupt
+ */
+#define rcar_thermal_irq_enable(p)	_rcar_thermal_irq_ctrl(p, 1)
+#define rcar_thermal_irq_disable(p)	_rcar_thermal_irq_ctrl(p, 0)
+static void _rcar_thermal_irq_ctrl(struct rcar_thermal_priv *priv, int enable)
+{
+	struct rcar_thermal_common *common = priv->common;
+	unsigned long flags;
+	u32 mask = 0x3 << rcar_id_to_shift(priv); /* enable Rising/Falling */
+
+	spin_lock_irqsave(&common->lock, flags);
+
+	rcar_thermal_common_bset(common, INTMSK, mask, enable ? 0 : mask);
+
+	spin_unlock_irqrestore(&common->lock, flags);
+}
+
+static void rcar_thermal_work(struct work_struct *work)
+{
+	struct rcar_thermal_priv *priv;
+
+	priv = container_of(work, struct rcar_thermal_priv, work.work);
+
+	rcar_thermal_update_temp(priv);
+	rcar_thermal_irq_enable(priv);
+	thermal_zone_device_update(priv->zone);
+}
+
+static u32 rcar_thermal_had_changed(struct rcar_thermal_priv *priv, u32 status)
+{
+	struct device *dev = rcar_priv_to_dev(priv);
+
+	status = (status >> rcar_id_to_shift(priv)) & 0x3;
+
+	if (status & 0x3) {
+		dev_dbg(dev, "thermal%d %s%s\n",
+			priv->id,
+			(status & 0x2) ? "Rising " : "",
+			(status & 0x1) ? "Falling" : "");
+	}
+
+	return status;
+}
+
+static irqreturn_t rcar_thermal_irq(int irq, void *data)
+{
+	struct rcar_thermal_common *common = data;
+	struct rcar_thermal_priv *priv;
+	unsigned long flags;
+	u32 status, mask;
+
+	spin_lock_irqsave(&common->lock, flags);
+
+	mask	= rcar_thermal_common_read(common, INTMSK);
+	status	= rcar_thermal_common_read(common, STR);
+	rcar_thermal_common_write(common, STR, 0x000F0F0F & mask);
+
+	spin_unlock_irqrestore(&common->lock, flags);
+
+	status = status & ~mask;
+
+	/*
+	 * check the status
+	 */
+	rcar_thermal_for_each_priv(priv, common) {
+		if (rcar_thermal_had_changed(priv, status)) {
+			rcar_thermal_irq_disable(priv);
+			schedule_delayed_work(&priv->work,
+					      msecs_to_jiffies(300));
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
 /*
  *		platform functions
  */
@@ -245,6 +364,7 @@ static int rcar_thermal_probe(struct platform_device *pdev)
 	struct resource *res, *irq;
 	int mres = 0;
 	int i;
+	int idle = IDLE_INTERVAL;
 
 	common = devm_kzalloc(dev, sizeof(*common), GFP_KERNEL);
 	if (!common) {
@@ -253,10 +373,13 @@ static int rcar_thermal_probe(struct platform_device *pdev)
 	}
 
 	INIT_LIST_HEAD(&common->head);
+	spin_lock_init(&common->lock);
 	common->dev = dev;
 
 	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 	if (irq) {
+		int ret;
+
 		/*
 		 * platform has IRQ support.
 		 * Then, drier use common register
@@ -267,6 +390,13 @@ static int rcar_thermal_probe(struct platform_device *pdev)
 			return -ENODEV;
 		}
 
+		ret = devm_request_irq(dev, irq->start, rcar_thermal_irq, 0,
+				       dev_name(dev), common);
+		if (ret) {
+			dev_err(dev, "irq request failed\n ");
+			return ret;
+		}
+
 		/*
 		 * rcar_has_irq_support() will be enabled
 		 */
@@ -275,6 +405,11 @@ static int rcar_thermal_probe(struct platform_device *pdev)
 			dev_err(dev, "Unable to ioremap thermal register\n");
 			return -ENOMEM;
 		}
+
+		/* enable temperature comparation */
+		rcar_thermal_common_write(common, ENR, 0x00030303);
+
+		idle = 0; /* polling delaye is not needed */
 	}
 
 	for (i = 0;; i++) {
@@ -295,19 +430,25 @@ static int rcar_thermal_probe(struct platform_device *pdev)
 		}
 
 		priv->common = common;
+		priv->id = i;
 		mutex_init(&priv->lock);
 		INIT_LIST_HEAD(&priv->list);
+		INIT_DELAYED_WORK(&priv->work, rcar_thermal_work);
+		rcar_thermal_update_temp(priv);
 
 		priv->zone = thermal_zone_device_register("rcar_thermal",
 						1, 0, priv,
 						&rcar_thermal_zone_ops, NULL, 0,
-						IDLE_INTERVAL);
+						idle);
 		if (IS_ERR(priv->zone)) {
 			dev_err(dev, "can't register thermal zone\n");
 			goto error_unregister;
 		}
 
 		list_move_tail(&priv->list, &common->head);
+
+		if (rcar_has_irq_support(priv))
+			rcar_thermal_irq_enable(priv);
 	}
 
 	platform_set_drvdata(pdev, common);