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path: root/drivers/clocksource/time-armada-370-xp.c
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Diffstat (limited to 'drivers/clocksource/time-armada-370-xp.c')
-rw-r--r--drivers/clocksource/time-armada-370-xp.c131
1 files changed, 77 insertions, 54 deletions
diff --git a/drivers/clocksource/time-armada-370-xp.c b/drivers/clocksource/time-armada-370-xp.c
index 847cab6f6e31..0198504ef6b0 100644
--- a/drivers/clocksource/time-armada-370-xp.c
+++ b/drivers/clocksource/time-armada-370-xp.c
@@ -13,6 +13,19 @@
*
* Timer 0 is used as free-running clocksource, while timer 1 is
* used as clock_event_device.
+ *
+ * ---
+ * Clocksource driver for Armada 370 and Armada XP SoC.
+ * This driver implements one compatible string for each SoC, given
+ * each has its own characteristics:
+ *
+ * * Armada 370 has no 25 MHz fixed timer.
+ *
+ * * Armada XP cannot work properly without such 25 MHz fixed timer as
+ * doing otherwise leads to using a clocksource whose frequency varies
+ * when doing cpufreq frequency changes.
+ *
+ * See Documentation/devicetree/bindings/timer/marvell,armada-370-xp-timer.txt
*/
#include <linux/init.h>
@@ -30,19 +43,18 @@
#include <linux/module.h>
#include <linux/sched_clock.h>
#include <linux/percpu.h>
-#include <linux/time-armada-370-xp.h>
/*
* Timer block registers.
*/
#define TIMER_CTRL_OFF 0x0000
-#define TIMER0_EN 0x0001
-#define TIMER0_RELOAD_EN 0x0002
-#define TIMER0_25MHZ 0x0800
+#define TIMER0_EN BIT(0)
+#define TIMER0_RELOAD_EN BIT(1)
+#define TIMER0_25MHZ BIT(11)
#define TIMER0_DIV(div) ((div) << 19)
-#define TIMER1_EN 0x0004
-#define TIMER1_RELOAD_EN 0x0008
-#define TIMER1_25MHZ 0x1000
+#define TIMER1_EN BIT(2)
+#define TIMER1_RELOAD_EN BIT(3)
+#define TIMER1_25MHZ BIT(12)
#define TIMER1_DIV(div) ((div) << 22)
#define TIMER_EVENTS_STATUS 0x0004
#define TIMER0_CLR_MASK (~0x1)
@@ -72,6 +84,18 @@ static u32 ticks_per_jiffy;
static struct clock_event_device __percpu *armada_370_xp_evt;
+static void timer_ctrl_clrset(u32 clr, u32 set)
+{
+ writel((readl(timer_base + TIMER_CTRL_OFF) & ~clr) | set,
+ timer_base + TIMER_CTRL_OFF);
+}
+
+static void local_timer_ctrl_clrset(u32 clr, u32 set)
+{
+ writel((readl(local_base + TIMER_CTRL_OFF) & ~clr) | set,
+ local_base + TIMER_CTRL_OFF);
+}
+
static u32 notrace armada_370_xp_read_sched_clock(void)
{
return ~readl(timer_base + TIMER0_VAL_OFF);
@@ -84,7 +108,6 @@ static int
armada_370_xp_clkevt_next_event(unsigned long delta,
struct clock_event_device *dev)
{
- u32 u;
/*
* Clear clockevent timer interrupt.
*/
@@ -98,11 +121,8 @@ armada_370_xp_clkevt_next_event(unsigned long delta,
/*
* Enable the timer.
*/
- u = readl(local_base + TIMER_CTRL_OFF);
- u = ((u & ~TIMER0_RELOAD_EN) | TIMER0_EN |
- TIMER0_DIV(TIMER_DIVIDER_SHIFT));
- writel(u, local_base + TIMER_CTRL_OFF);
-
+ local_timer_ctrl_clrset(TIMER0_RELOAD_EN,
+ TIMER0_EN | TIMER0_DIV(TIMER_DIVIDER_SHIFT));
return 0;
}
@@ -110,8 +130,6 @@ static void
armada_370_xp_clkevt_mode(enum clock_event_mode mode,
struct clock_event_device *dev)
{
- u32 u;
-
if (mode == CLOCK_EVT_MODE_PERIODIC) {
/*
@@ -123,18 +141,14 @@ armada_370_xp_clkevt_mode(enum clock_event_mode mode,
/*
* Enable timer.
*/
-
- u = readl(local_base + TIMER_CTRL_OFF);
-
- writel((u | TIMER0_EN | TIMER0_RELOAD_EN |
- TIMER0_DIV(TIMER_DIVIDER_SHIFT)),
- local_base + TIMER_CTRL_OFF);
+ local_timer_ctrl_clrset(0, TIMER0_RELOAD_EN |
+ TIMER0_EN |
+ TIMER0_DIV(TIMER_DIVIDER_SHIFT));
} else {
/*
* Disable timer.
*/
- u = readl(local_base + TIMER_CTRL_OFF);
- writel(u & ~TIMER0_EN, local_base + TIMER_CTRL_OFF);
+ local_timer_ctrl_clrset(TIMER0_EN, 0);
/*
* ACK pending timer interrupt.
@@ -163,14 +177,14 @@ static irqreturn_t armada_370_xp_timer_interrupt(int irq, void *dev_id)
*/
static int armada_370_xp_timer_setup(struct clock_event_device *evt)
{
- u32 u;
+ u32 clr = 0, set = 0;
int cpu = smp_processor_id();
- u = readl(local_base + TIMER_CTRL_OFF);
if (timer25Mhz)
- writel(u | TIMER0_25MHZ, local_base + TIMER_CTRL_OFF);
+ set = TIMER0_25MHZ;
else
- writel(u & ~TIMER0_25MHZ, local_base + TIMER_CTRL_OFF);
+ clr = TIMER0_25MHZ;
+ local_timer_ctrl_clrset(clr, set);
evt->name = "armada_370_xp_per_cpu_tick",
evt->features = CLOCK_EVT_FEAT_ONESHOT |
@@ -217,36 +231,21 @@ static struct notifier_block armada_370_xp_timer_cpu_nb = {
.notifier_call = armada_370_xp_timer_cpu_notify,
};
-void __init armada_370_xp_timer_init(void)
+static void __init armada_370_xp_timer_common_init(struct device_node *np)
{
- u32 u;
- struct device_node *np;
+ u32 clr = 0, set = 0;
int res;
- np = of_find_compatible_node(NULL, NULL, "marvell,armada-370-xp-timer");
timer_base = of_iomap(np, 0);
WARN_ON(!timer_base);
local_base = of_iomap(np, 1);
- if (of_find_property(np, "marvell,timer-25Mhz", NULL)) {
- /* The fixed 25MHz timer is available so let's use it */
- u = readl(timer_base + TIMER_CTRL_OFF);
- writel(u | TIMER0_25MHZ,
- timer_base + TIMER_CTRL_OFF);
- timer_clk = 25000000;
- } else {
- unsigned long rate = 0;
- struct clk *clk = of_clk_get(np, 0);
- WARN_ON(IS_ERR(clk));
- rate = clk_get_rate(clk);
-
- u = readl(timer_base + TIMER_CTRL_OFF);
- writel(u & ~(TIMER0_25MHZ),
- timer_base + TIMER_CTRL_OFF);
-
- timer_clk = rate / TIMER_DIVIDER;
- timer25Mhz = false;
- }
+ if (timer25Mhz)
+ set = TIMER0_25MHZ;
+ else
+ clr = TIMER0_25MHZ;
+ timer_ctrl_clrset(clr, set);
+ local_timer_ctrl_clrset(clr, set);
/*
* We use timer 0 as clocksource, and private(local) timer 0
@@ -268,10 +267,8 @@ void __init armada_370_xp_timer_init(void)
writel(0xffffffff, timer_base + TIMER0_VAL_OFF);
writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF);
- u = readl(timer_base + TIMER_CTRL_OFF);
-
- writel((u | TIMER0_EN | TIMER0_RELOAD_EN |
- TIMER0_DIV(TIMER_DIVIDER_SHIFT)), timer_base + TIMER_CTRL_OFF);
+ timer_ctrl_clrset(0, TIMER0_EN | TIMER0_RELOAD_EN |
+ TIMER0_DIV(TIMER_DIVIDER_SHIFT));
clocksource_mmio_init(timer_base + TIMER0_VAL_OFF,
"armada_370_xp_clocksource",
@@ -293,3 +290,29 @@ void __init armada_370_xp_timer_init(void)
if (!res)
armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt));
}
+
+static void __init armada_xp_timer_init(struct device_node *np)
+{
+ struct clk *clk = of_clk_get_by_name(np, "fixed");
+
+ /* The 25Mhz fixed clock is mandatory, and must always be available */
+ BUG_ON(IS_ERR(clk));
+ timer_clk = clk_get_rate(clk);
+
+ armada_370_xp_timer_common_init(np);
+}
+CLOCKSOURCE_OF_DECLARE(armada_xp, "marvell,armada-xp-timer",
+ armada_xp_timer_init);
+
+static void __init armada_370_timer_init(struct device_node *np)
+{
+ struct clk *clk = of_clk_get(np, 0);
+
+ BUG_ON(IS_ERR(clk));
+ timer_clk = clk_get_rate(clk) / TIMER_DIVIDER;
+ timer25Mhz = false;
+
+ armada_370_xp_timer_common_init(np);
+}
+CLOCKSOURCE_OF_DECLARE(armada_370, "marvell,armada-370-timer",
+ armada_370_timer_init);