[PATCH v16 10/15] clocksource/drivers/arm_arch_timer: Refactor the timer init code to prepare for GTDT

[fu . wei]

From: Fu Wei <fu.wei@xxxxxxxxxx>

The patch refactor original memory-mapped timer init code:
    (1) Extract a subfunction for detecting a bast time frame:
        is_best_frame.
    (2) Refactor "arch_timer_mem_init", make it become a common code for
        memory-mapped timer init.
    (3) Add a new function "arch_timer_mem_of_init" for DT init.

Signed-off-by: Fu Wei <fu.wei@xxxxxxxxxx>
---
 drivers/clocksource/arm_arch_timer.c | 162 +++++++++++++++++++++++------------
 1 file changed, 107 insertions(+), 55 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 9ddc091..0836bb9 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -923,17 +923,35 @@ static int __init arch_timer_of_init(struct device_node *np)
 CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init);
 CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_of_init);
 
-static int __init arch_timer_mem_init(struct device_node *np)
+static bool __init is_best_frame(void __iomem *cntctlbase, u32 cnttidr, int n)
+{
+	u32 cntacr = CNTACR_RFRQ | CNTACR_RWPT | CNTACR_RPCT | CNTACR_RWVT |
+		     CNTACR_RVOFF | CNTACR_RVCT;
+
+	/* Try enabling everything, and see what sticks */
+	writel_relaxed(cntacr, cntctlbase + CNTACR(n));
+	cntacr = readl_relaxed(cntctlbase + CNTACR(n));
+
+	if ((cnttidr & CNTTIDR_VIRT(n)) &&
+	    !(~cntacr & (CNTACR_RWVT | CNTACR_RVCT)))
+		arch_timer_mem_use_virtual = true;
+	else if (~cntacr & (CNTACR_RWPT | CNTACR_RPCT))
+		return false;
+
+	return true;
+}
+
+static int __init arch_timer_mem_init(struct arch_timer_mem *timer_mem)
 {
-	struct device_node *frame, *best_frame = NULL;
 	void __iomem *cntctlbase, *base;
-	unsigned int irq, ret = -EINVAL;
+	struct arch_timer_mem_frame *best_frame = NULL;
+	unsigned int irq;
 	u32 cnttidr;
+	int i, ret;
 
-	arch_timers_present |= ARCH_TIMER_TYPE_MEM;
-	cntctlbase = of_iomap(np, 0);
+	cntctlbase = ioremap(timer_mem->cntctlbase, timer_mem->size);
 	if (!cntctlbase) {
-		pr_err("Can't find CNTCTLBase\n");
+		pr_err("Can't map CNTCTLBase.\n");
 		return -ENXIO;
 	}
 
@@ -943,76 +961,110 @@ static int __init arch_timer_mem_init(struct device_node *np)
 	 * Try to find a virtual capable frame. Otherwise fall back to a
 	 * physical capable frame.
 	 */
-	for_each_available_child_of_node(np, frame) {
-		int n;
-		u32 cntacr;
-
-		if (of_property_read_u32(frame, "frame-number", &n)) {
-			pr_err("Missing frame-number\n");
-			of_node_put(frame);
-			goto out;
-		}
-
-		/* Try enabling everything, and see what sticks */
-		cntacr = CNTACR_RFRQ | CNTACR_RWPT | CNTACR_RPCT |
-			 CNTACR_RWVT | CNTACR_RVOFF | CNTACR_RVCT;
-		writel_relaxed(cntacr, cntctlbase + CNTACR(n));
-		cntacr = readl_relaxed(cntctlbase + CNTACR(n));
-
-		if ((cnttidr & CNTTIDR_VIRT(n)) &&
-		    !(~cntacr & (CNTACR_RWVT | CNTACR_RVCT))) {
-			of_node_put(best_frame);
-			best_frame = frame;
-			arch_timer_mem_use_virtual = true;
-			break;
+	for (i = 0; i < timer_mem->num_frames; i++) {
+		if (is_best_frame(cntctlbase, cnttidr,
+				  timer_mem->frame[i].frame_nr)) {
+			best_frame = &timer_mem->frame[i];
+			if (arch_timer_mem_use_virtual)
+				break;
 		}
-
-		if (~cntacr & (CNTACR_RWPT | CNTACR_RPCT))
-			continue;
-
-		of_node_put(best_frame);
-		best_frame = of_node_get(frame);
 	}
+	iounmap(cntctlbase);
 
-	ret= -ENXIO;
-	base = arch_counter_base = of_iomap(best_frame, 0);
-	if (!base) {
-		pr_err("Can't map frame's registers\n");
-		goto out;
+	if (!best_frame) {
+		pr_err("Can't find frame for register\n");
+		return -EINVAL;
 	}
 
 	if (arch_timer_mem_use_virtual)
-		irq = irq_of_parse_and_map(best_frame, ARCH_TIMER_VIRT_SPI);
+		irq = best_frame->virt_irq;
 	else
-		irq = irq_of_parse_and_map(best_frame, ARCH_TIMER_PHYS_SPI);
+		irq = best_frame->phys_irq;
 
-	ret = -EINVAL;
 	if (!irq) {
 		pr_err("Frame missing %s irq",
 		       arch_timer_mem_use_virtual ? "virt" : "phys");
-		goto out;
+		return -EINVAL;
 	}
 
-	/*
-	 * Try to determine the frequency from the device tree,
-	 * if fail, get the frequency from CNTFRQ.
-	 */
-	if (!arch_timer_rate &&
-	    of_property_read_u32(np, "clock-frequency", &arch_timer_rate))
-		arch_timer_detect_rate(base);
+	base = ioremap(best_frame->cntbase, best_frame->size);
+	if (!base) {
+		pr_err("Can't map frame's registers\n");
+		return -ENXIO;
+	}
+
+	arch_timer_detect_rate(base);
 
 	ret = arch_timer_mem_register(base, irq);
-	if (ret)
+	if (ret) {
+		iounmap(base);
+		return ret;
+	}
+
+	arch_counter_base = base;
+	arch_timers_present |= ARCH_TIMER_TYPE_MEM;
+
+	return 0;
+}
+
+static int __init arch_timer_mem_of_init(struct device_node *np)
+{
+	struct arch_timer_mem *timer_mem;
+	struct device_node *frame_node;
+	struct resource res;
+	int i, ret = -EINVAL;
+
+	timer_mem = kzalloc(sizeof(*timer_mem), GFP_KERNEL);
+	if (!timer_mem)
+		return -ENOMEM;
+
+	if (of_address_to_resource(np, 0, &res))
 		goto out;
+	timer_mem->cntctlbase = res.start;
+	timer_mem->size = resource_size(&res);
 
-	return arch_timer_common_init();
+	i = 0;
+	for_each_available_child_of_node(np, frame_node) {
+		int n;
+		struct arch_timer_mem_frame *frame = &timer_mem->frame[i];
+
+		if (of_property_read_u32(frame_node, "frame-number", &n)) {
+			pr_err("Missing frame-number\n");
+			of_node_put(frame_node);
+			goto out;
+		}
+		frame->frame_nr = n;
+
+		if (of_address_to_resource(frame_node, 0, &res)) {
+			of_node_put(frame_node);
+			goto out;
+		}
+		frame->cntbase = res.start;
+		frame->size = resource_size(&res);
+
+		frame->virt_irq = irq_of_parse_and_map(frame_node,
+						       ARCH_TIMER_VIRT_SPI);
+		frame->phys_irq = irq_of_parse_and_map(frame_node,
+						       ARCH_TIMER_PHYS_SPI);
+
+		if (++i >= ARCH_TIMER_MEM_MAX_FRAMES)
+			break;
+	}
+	timer_mem->num_frames = i;
+
+	/* Try to determine the frequency from the device tree */
+	if (!arch_timer_rate)
+		of_property_read_u32(np, "clock-frequency", &arch_timer_rate);
+
+	ret = arch_timer_mem_init(timer_mem);
+	if (!ret)
+		ret = arch_timer_common_init();
 out:
-	iounmap(cntctlbase);
-	of_node_put(best_frame);
+	kfree(timer_mem);
 	return ret;
 }
 CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
-		       arch_timer_mem_init);
+		       arch_timer_mem_of_init);
 
 #ifdef CONFIG_ACPI
 static int __init map_generic_timer_interrupt(u32 interrupt, u32 flags)
-- 
2.7.4