[PATCH v14 7/9] clocksource/drivers/arm_arch_timer: Refactor the timer init code to prepare for GTDT

From: fu . wei
Date: Wed Sep 28 2016 - 14:19:08 EST


From: Fu Wei <fu.wei@xxxxxxxxxx>

The patch refactor original memory-mapped timer init code:
(1) extract some subfunction for reusing some common code
a. get_cnttidr
b. is_best_frame
(2) move base address and irq code for arch_timer_mem to
arch_timer_mem_register

Signed-off-by: Fu Wei <fu.wei@xxxxxxxxxx>
---
drivers/clocksource/arm_arch_timer.c | 159 +++++++++++++++++++++--------------
1 file changed, 96 insertions(+), 63 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index c7b0040..e78095f 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -57,6 +57,7 @@
static unsigned arch_timers_present __initdata;

static void __iomem *arch_counter_base;
+static void __iomem *cntctlbase __initdata;

struct arch_timer {
void __iomem *base;
@@ -656,15 +657,49 @@ out:
return err;
}

-static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq)
+static int __init arch_timer_mem_register(struct device_node *np, void *frame)
{
- int ret;
- irq_handler_t func;
+ struct device_node *frame_node = NULL;
struct arch_timer *t;
+ void __iomem *base;
+ irq_handler_t func;
+ unsigned int irq;
+ int ret;
+
+ if (!frame)
+ return -EINVAL;
+
+ if (np) {
+ frame_node = (struct device_node *)frame;
+ base = of_iomap(frame_node, 0);
+ arch_timer_detect_rate(base, np);
+ if (arch_timer_mem_use_virtual)
+ irq = irq_of_parse_and_map(frame_node, VIRT_SPI);
+ else
+ irq = irq_of_parse_and_map(frame_node, PHYS_SPI);
+ } else {
+ pr_err("Device node is missing.\n");
+ return -EINVAL;
+ }
+
+ if (!base) {
+ pr_err("Can't map frame's registers\n");
+ return -ENXIO;
+ }
+ if (!irq) {
+ pr_err("Frame missing %s irq",
+ arch_timer_mem_use_virtual ? "virt" : "phys");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ arch_counter_base = base;

t = kzalloc(sizeof(*t), GFP_KERNEL);
- if (!t)
- return -ENOMEM;
+ if (!t) {
+ ret = -ENOMEM;
+ goto out;
+ }

t->base = base;
t->evt.irq = irq;
@@ -676,11 +711,13 @@ static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq)
func = arch_timer_handler_phys_mem;

ret = request_irq(irq, func, IRQF_TIMER, "arch_mem_timer", &t->evt);
- if (ret) {
- pr_err("Failed to request mem timer irq\n");
- kfree(t);
- }
+ if (!ret)
+ return 0;

+ pr_err("Failed to request mem timer irq\n");
+ kfree(t);
+out:
+ iounmap(base);
return ret;
}

@@ -803,21 +840,54 @@ 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 int __init get_cnttidr(struct device_node *np, u32 *cnttidr)
{
- struct device_node *frame, *best_frame = NULL;
- void __iomem *cntctlbase, *base;
- unsigned int irq, ret = -EINVAL;
- u32 cnttidr;
+ if (!cnttidr)
+ return -EINVAL;
+
+ if (np)
+ cntctlbase = of_iomap(np, 0);
+ else
+ return -EINVAL;

- arch_timers_present |= ARCH_MEM_TIMER;
- cntctlbase = of_iomap(np, 0);
if (!cntctlbase) {
pr_err("Can't find CNTCTLBase\n");
return -ENXIO;
}

- cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
+ *cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
+ return 0;
+}
+
+static bool __init is_best_frame(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 device_node *np)
+{
+ struct device_node *frame, *best_frame = NULL;
+ unsigned int ret;
+ u32 cnttidr;
+
+ arch_timers_present |= ARCH_MEM_TIMER;
+
+ ret = get_cnttidr(np, &cnttidr);
+ if (ret)
+ return ret;

/*
* Try to find a virtual capable frame. Otherwise fall back to a
@@ -825,60 +895,23 @@ static int __init arch_timer_mem_init(struct device_node *np)
*/
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");
+ pr_err("Missing frame-number.\n");
of_node_put(frame);
+ ret = -EINVAL;
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))) {
+ if (is_best_frame(cnttidr, n)) {
of_node_put(best_frame);
- best_frame = frame;
- arch_timer_mem_use_virtual = true;
- break;
+ best_frame = of_node_get(frame);
+ 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);
- }
-
- 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 (arch_timer_mem_use_virtual)
- irq = irq_of_parse_and_map(best_frame, VIRT_SPI);
- else
- irq = irq_of_parse_and_map(best_frame, PHYS_SPI);
-
- ret = -EINVAL;
- if (!irq) {
- pr_err("Frame missing %s irq",
- arch_timer_mem_use_virtual ? "virt" : "phys");
- goto out;
- }
-
- arch_timer_detect_rate(base, np);
- ret = arch_timer_mem_register(base, irq);
- if (ret)
- goto out;
-
- return arch_timer_common_init();
+ ret = arch_timer_mem_register(np, best_frame);
+ if (!ret)
+ ret = arch_timer_common_init();
out:
iounmap(cntctlbase);
of_node_put(best_frame);
--
2.7.4