clocksource: nomadik-mtu: support of probe

Support device tree probe of the nomadik-mtu clocksource.
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>

drivers/clocksource/nomadik-mtu.c

@@ -13,6 +13,9 @@
 #include <linux/io.h>
 #include <linux/clockchips.h>
 #include <linux/clocksource.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
 #include <linux/clk.h>
 #include <linux/jiffies.h>
 #include <linux/delay.h>
@@ -188,22 +191,15 @@ static struct irqaction nmdk_timer_irq = {
 	.dev_id		= &nmdk_clkevt,
 };
 
-void __init nmdk_timer_init(void __iomem *base, int irq)
+static void __init __nmdk_timer_init(void __iomem *base, int irq,
+				     struct clk *pclk, struct clk *clk)
 {
 	unsigned long rate;
-	struct clk *clk0, *pclk0;
 
 	mtu_base = base;
 
-	pclk0 = clk_get_sys("mtu0", "apb_pclk");
-	BUG_ON(IS_ERR(pclk0));
-	BUG_ON(clk_prepare(pclk0) < 0);
-	BUG_ON(clk_enable(pclk0) < 0);
-
-	clk0 = clk_get_sys("mtu0", NULL);
-	BUG_ON(IS_ERR(clk0));
-	BUG_ON(clk_prepare(clk0) < 0);
-	BUG_ON(clk_enable(clk0) < 0);
+	BUG_ON(clk_prepare_enable(pclk));
+	BUG_ON(clk_prepare_enable(clk));
 
 	/*
 	 * Tick rate is 2.4MHz for Nomadik and 2.4Mhz, 100MHz or 133 MHz
@@ -213,7 +209,7 @@ void __init nmdk_timer_init(void __iomem *base, int irq)
 	 * to wake-up at a max 127s a head in time. Dividing a 2.4 MHz timer
 	 * with 16 gives too low timer resolution.
 	 */
-	rate = clk_get_rate(clk0);
+	rate = clk_get_rate(clk);
 	if (rate > 32000000) {
 		rate /= 16;
 		clk_prescale = MTU_CRn_PRESCALE_16;
@@ -247,3 +243,53 @@ void __init nmdk_timer_init(void __iomem *base, int irq)
 	mtu_delay_timer.freq = rate;
 	register_current_timer_delay(&mtu_delay_timer);
 }
+
+void __init nmdk_timer_init(void __iomem *base, int irq)
+{
+	struct clk *clk0, *pclk0;
+
+	pclk0 = clk_get_sys("mtu0", "apb_pclk");
+	BUG_ON(IS_ERR(pclk0));
+	clk0 = clk_get_sys("mtu0", NULL);
+	BUG_ON(IS_ERR(clk0));
+
+	__nmdk_timer_init(base, irq, pclk0, clk0);
+}
+
+static struct of_device_id nmdk_timer_match[] __initconst = {
+	{ .compatible = "st,nomadik-mtu" },
+	{}
+};
+
+static void __init nmdk_timer_of_init(void)
+{
+	struct device_node *node;
+	struct clk *pclk;
+	struct clk *clk;
+	void __iomem *base;
+	int irq;
+
+	node = of_find_matching_node(NULL, nmdk_timer_match);
+	if (!node)
+		panic("No timer node");
+
+	base = of_iomap(node, 0);
+	if (!base)
+		panic("Can't remap registers");
+
+	pclk = of_clk_get_by_name(node, "apb_pclk");
+	if (IS_ERR(pclk))
+		panic("could not get apb_pclk");
+
+	clk = of_clk_get_by_name(node, "timclk");
+	if (IS_ERR(clk))
+		panic("could not get timclk");
+
+	irq = irq_of_parse_and_map(node, 0);
+	if (irq <= 0)
+		panic("Can't parse IRQ");
+
+	__nmdk_timer_init(base, irq, pclk, clk);
+}
+CLOCKSOURCE_OF_DECLARE(nomadik_mtu, "st,nomadik-mtu",
+		       nmdk_timer_of_init);