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authorBoris BREZILLON <b.brezillon@overkiz.com>2013-10-11 13:46:28 +0200
committerNicolas Ferre <nicolas.ferre@atmel.com>2013-12-02 15:31:26 +0100
commit7034be876e6b6f98b0babf359c21aab6b40bb9bd (patch)
tree066bdbb3aa92a802e08f2a2c87f2cdfc257eb885 /arch/arm/mach-at91
parentdt: binding: add at91 clks dt bindings documentation (diff)
downloadlinux-7034be876e6b6f98b0babf359c21aab6b40bb9bd.tar.xz
linux-7034be876e6b6f98b0babf359c21aab6b40bb9bd.zip
ARM: at91: move pit timer to common clk framework
Use device tree to get the source clock of the PIT (Periodic Interval Timer). If the clock is not found in device tree (or dt is not enabled) we'll try to get it using clk_lookup definitions. Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com> Acked-by: Mike Turquette <mturquette@linaro.org> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Diffstat (limited to 'arch/arm/mach-at91')
-rw-r--r--arch/arm/mach-at91/at91sam926x_time.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/arch/arm/mach-at91/at91sam926x_time.c b/arch/arm/mach-at91/at91sam926x_time.c
index bb392320a0dd..0f04ffe9c5a8 100644
--- a/arch/arm/mach-at91/at91sam926x_time.c
+++ b/arch/arm/mach-at91/at91sam926x_time.c
@@ -39,6 +39,7 @@
static u32 pit_cycle; /* write-once */
static u32 pit_cnt; /* access only w/system irq blocked */
static void __iomem *pit_base_addr __read_mostly;
+static struct clk *mck;
static inline unsigned int pit_read(unsigned int reg_offset)
{
@@ -195,10 +196,14 @@ static int __init of_at91sam926x_pit_init(void)
if (!pit_base_addr)
goto node_err;
+ mck = of_clk_get(np, 0);
+
/* Get the interrupts property */
ret = irq_of_parse_and_map(np, 0);
if (!ret) {
pr_crit("AT91: PIT: Unable to get IRQ from DT\n");
+ if (!IS_ERR(mck))
+ clk_put(mck);
goto ioremap_err;
}
at91sam926x_pit_irq.irq = ret;
@@ -230,6 +235,8 @@ void __init at91sam926x_pit_init(void)
unsigned bits;
int ret;
+ mck = ERR_PTR(-ENOENT);
+
/* For device tree enabled device: initialize here */
of_at91sam926x_pit_init();
@@ -237,7 +244,12 @@ void __init at91sam926x_pit_init(void)
* Use our actual MCK to figure out how many MCK/16 ticks per
* 1/HZ period (instead of a compile-time constant LATCH).
*/
- pit_rate = clk_get_rate(clk_get(NULL, "mck")) / 16;
+ if (IS_ERR(mck))
+ mck = clk_get(NULL, "mck");
+
+ if (IS_ERR(mck))
+ panic("AT91: PIT: Unable to get mck clk\n");
+ pit_rate = clk_get_rate(mck) / 16;
pit_cycle = (pit_rate + HZ/2) / HZ;
WARN_ON(((pit_cycle - 1) & ~AT91_PIT_PIV) != 0);