libreCMC/target/linux/ramips/patches-4.4/0014-arch-mips-cleanup-cevt-rt3352.patch

From e6ed424c36458aff8738fb1fbb0141196678058a Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Mon, 7 Dec 2015 17:17:23 +0100
Subject: [PATCH 14/53] arch: mips: cleanup cevt-rt3352

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 arch/mips/ralink/cevt-rt3352.c |   85 ++++++++++++++++++++++++++--------------
 1 file changed, 56 insertions(+), 29 deletions(-)

--- a/arch/mips/ralink/cevt-rt3352.c
+++ b/arch/mips/ralink/cevt-rt3352.c
@@ -52,7 +52,7 @@ static inline void mt7620_freq_scaling(s
 
 	sdev->freq_scale = status;
 
-	pr_info("%s: %s autosleep mode\n", systick.dev.name,
+	pr_info("%s: %s autosleep mode\n", sdev->dev.name,
 			(status) ? ("enable") : ("disable"));
 	if (status)
 		rt_sysc_w32(rt_sysc_r32(CLK_LUT_CFG) | SLEEP_EN, CLK_LUT_CFG);
@@ -60,18 +60,33 @@ static inline void mt7620_freq_scaling(s
 		rt_sysc_w32(rt_sysc_r32(CLK_LUT_CFG) & ~SLEEP_EN, CLK_LUT_CFG);
 }
 
+static inline unsigned int read_count(struct systick_device *sdev)
+{
+	return ioread32(sdev->membase + SYSTICK_COUNT);
+}
+
+static inline unsigned int read_compare(struct systick_device *sdev)
+{
+	return ioread32(sdev->membase + SYSTICK_COMPARE);
+}
+
+static inline void write_compare(struct systick_device *sdev, unsigned int val)
+{
+	iowrite32(val, sdev->membase + SYSTICK_COMPARE);
+}
+
 static int systick_next_event(unsigned long delta,
 				struct clock_event_device *evt)
 {
 	struct systick_device *sdev;
-	u32 count;
+	int res;
 
 	sdev = container_of(evt, struct systick_device, dev);
-	count = ioread32(sdev->membase + SYSTICK_COUNT);
-	count = (count + delta) % SYSTICK_FREQ;
-	iowrite32(count, sdev->membase + SYSTICK_COMPARE);
+	delta += read_count(sdev);
+	write_compare(sdev, delta);
+	res = ((int)(read_count(sdev) - delta) >= 0) ? -ETIME : 0;
 
-	return 0;
+	return res;
 }
 
 static void systick_event_handler(struct clock_event_device *dev)
@@ -81,20 +96,25 @@ static void systick_event_handler(struct
 
 static irqreturn_t systick_interrupt(int irq, void *dev_id)
 {
-	struct clock_event_device *dev = (struct clock_event_device *) dev_id;
+	int ret = 0;
+	struct clock_event_device *cdev;
+	struct systick_device *sdev;
 
-	dev->event_handler(dev);
+	if (read_c0_cause() & STATUSF_IP7) {
+		cdev = (struct clock_event_device *) dev_id;
+		sdev = container_of(cdev, struct systick_device, dev);
+
+		/* Clear Count/Compare Interrupt */
+		write_compare(sdev, read_compare(sdev));
+		cdev->event_handler(cdev);
+		ret = 1;
+	}
 
-	return IRQ_HANDLED;
+	return IRQ_RETVAL(ret);
 }
 
 static struct systick_device systick = {
 	.dev = {
-		/*
-		 * cevt-r4k uses 300, make sure systick
-		 * gets used if available
-		 */
-		.rating			= 310,
 		.features		= CLOCK_EVT_FEAT_ONESHOT,
 		.set_next_event		= systick_next_event,
 		.set_state_shutdown	= systick_shutdown,
@@ -116,9 +136,9 @@ static int systick_shutdown(struct clock
 	sdev = container_of(evt, struct systick_device, dev);
 
 	if (sdev->irq_requested)
-		free_irq(systick.dev.irq, &systick_irqaction);
+		remove_irq(systick.dev.irq, &systick_irqaction);
 	sdev->irq_requested = 0;
-	iowrite32(0, systick.membase + SYSTICK_CONFIG);
+	iowrite32(CFG_CNT_EN, systick.membase + SYSTICK_CONFIG);
 
 	if (systick_freq_scaling)
 		systick_freq_scaling(sdev, 0);
@@ -145,38 +165,45 @@ static int systick_set_oneshot(struct cl
 }
 
 static const struct of_device_id systick_match[] = {
-	{ .compatible = "ralink,mt7620-systick", .data = mt7620_freq_scaling},
+	{ .compatible = "ralink,mt7620a-systick", .data = mt7620_freq_scaling},
 	{},
 };
 
 static void __init ralink_systick_init(struct device_node *np)
 {
 	const struct of_device_id *match;
+	int rating = 200;
 
 	systick.membase = of_iomap(np, 0);
 	if (!systick.membase)
 		return;
 
 	match = of_match_node(systick_match, np);
-	if (match)
+	if (match) {
 		systick_freq_scaling = match->data;
+		/*
+		 * cevt-r4k uses 300, make sure systick
+		 * gets used if available
+		 */
+		rating = 310;
+	}
 
-	systick_irqaction.name = np->name;
-	systick.dev.name = np->name;
-	clockevents_calc_mult_shift(&systick.dev, SYSTICK_FREQ, 60);
-	systick.dev.max_delta_ns = clockevent_delta2ns(0x7fff, &systick.dev);
-	systick.dev.min_delta_ns = clockevent_delta2ns(0x3, &systick.dev);
+	/* enable counter than register clock source */
+	iowrite32(CFG_CNT_EN, systick.membase + SYSTICK_CONFIG);
+	clocksource_mmio_init(systick.membase + SYSTICK_COUNT, np->name,
+			SYSTICK_FREQ, rating, 16, clocksource_mmio_readl_up);
+
+	/* register clock event */
 	systick.dev.irq = irq_of_parse_and_map(np, 0);
 	if (!systick.dev.irq) {
 		pr_err("%s: request_irq failed", np->name);
 		return;
 	}
-
-	clocksource_mmio_init(systick.membase + SYSTICK_COUNT, np->name,
-			SYSTICK_FREQ, 301, 16, clocksource_mmio_readl_up);
-
-	clockevents_register_device(&systick.dev);
-
+	systick_irqaction.name = np->name;
+	systick.dev.name = np->name;
+	systick.dev.rating = rating;
+	systick.dev.cpumask = cpumask_of(0);
+	clockevents_config_and_register(&systick.dev, SYSTICK_FREQ, 0x3, 0x7fff);
 	pr_info("%s: running - mult: %d, shift: %d\n",
 			np->name, systick.dev.mult, systick.dev.shift);
 }