microblaze: Add support for CCF

Add support for CCF for Microblaze.

Old binding:
system_timer: system-timer@41c00000 {
	clock-frequency = <75000000>;
	...
}

New binding:
system_timer: system-timer@41c00000 {
	clocks = <&clk_bus>;
	...
}

Both should be supported for a while

Microblaze clock binding:
clocks {
	#address-cells = <1>;
	#size-cells = <0>;
	clk_bus: bus {
		#clock-cells = <0>;
		clock-frequency = <75000000>;
		clock-output-names = "bus";
		compatible = "fixed-clock";
		reg = <1>;
	} ;
	clk_cpu: cpu {
		#clock-cells = <0>;
		clock-frequency = <75000000>;
		clock-output-names = "cpu";
		compatible = "fixed-clock";
		reg = <0>;
	} ;
} ;

Signed-off-by: Michal Simek <michal.simek@xilinx.com>

1 files changed, 14 insertions, 4 deletions

diff --git a/arch/microblaze/kernel/timer.c b/arch/microblaze/kernel/timer.c
index 3e39b1082fdf..55b19400951f 100644
--- a/arch/microblaze/kernel/timer.c
+++ b/arch/microblaze/kernel/timer.c
@@ -230,9 +230,9 @@ static int timer_initialized;
 
 static void __init xilinx_timer_init(struct device_node *timer)
 {
+        struct clk *clk;
         u32 irq;
         u32 timer_num = 1;
-        int ret;
 
         timer_baseaddr = of_iomap(timer, 0);
         if (!timer_baseaddr) {
@@ -250,10 +250,20 @@ static void __init xilinx_timer_init(struct device_node *timer)
 
         pr_info("%s: irq=%d\n", timer->full_name, irq);
 
-        /* If there is clock-frequency property than use it */
-        ret = of_property_read_u32(timer, "clock-frequency", &timer_clock_freq);
-        if (ret < 0)
+        clk = of_clk_get(timer, 0);
+        if (IS_ERR(clk)) {
+                pr_err("ERROR: timer CCF input clock not found\n");
+                /* If there is clock-frequency property than use it */
+                of_property_read_u32(timer, "clock-frequency",
+                                    &timer_clock_freq);
+        } else {
+                timer_clock_freq = clk_get_rate(clk);
+        }
+
+        if (!timer_clock_freq) {
+                pr_err("ERROR: Using CPU clock frequency\n");
                 timer_clock_freq = cpuinfo.cpu_clock_freq;
+        }
 
         freq_div_hz = timer_clock_freq / HZ;