provide a system clock to be used by the MIPS timer

Signed-off-by: Florian Fainelli <florian@openwrt.org>

SVN-Revision: 34550

target/linux/adm8668/files/arch/mips/adm8668/Makefile

@@ -3,5 +3,5 @@
 #
 
 obj-y	 	:= irq.o pci.o prom.o platform.o proc.o \
-		   setup.o time.o early_printk.o clock.o \
+		   setup.o clock.o time.o early_printk.o \
 		   net_core.o net_intr.o

target/linux/adm8668/files/arch/mips/adm8668/clock.c

@@ -22,12 +22,19 @@ static struct clk uart_clk = {
 	.rate	= ADM8668_UARTCLK_FREQ,
 };
 
+static struct clk sys_clk;
+
 struct clk *clk_get(struct device *dev, const char *id)
 {
-	const char *name = dev_name(dev);
+	const char *lookup = id;
+
+	if (dev)
+		lookup = dev_name(dev);
 
-	if (!strcmp(name, "apb:uart0"))
+	if (!strcmp(lookup, "apb:uart0"))
 		return &uart_clk;
+	if (!strcmp(lookup, "sys"))
+		return &sys_clk;
 
 	return ERR_PTR(-ENOENT);
 }
@@ -54,3 +61,16 @@ void clk_put(struct clk *clk)
 {
 }
 EXPORT_SYMBOL(clk_put);
+
+void __init adm8668_init_clocks(void)
+{
+	u32 adj;
+
+	/* adjustable clock selection
+	 * CR3 bit 14~11, 0000 -> 175MHz, 0001 -> 180MHz, etc...
+	 */
+	adj = (ADM8668_CONFIG_REG(ADM8668_CR3) >> 11) & 0xf;
+	sys_clk.rate = SYS_CLOCK + adj * 5000000;
+
+	pr_info("ADM8668 CPU clock: %lu MHz\n", sys_clk.rate / 1000000);
+}

target/linux/adm8668/files/arch/mips/adm8668/time.c

 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/clk.h>
 
 #include <asm/time.h>
 #include <adm8668.h>
 
 void __init plat_time_init(void)
 {
-	int adj = (ADM8668_CONFIG_REG(ADM8668_CR3) >> 11) & 0xf;
+	struct clk *sys_clk;
 
-	/* adjustable clock selection
-	   CR3 bit 14~11, 0000 -> 175MHz, 0001 -> 180MHz, etc... */
+	adm8668_init_clocks();
 
-	mips_hpt_frequency = (SYS_CLOCK + adj * 5000000) / 2;
-	printk("ADM8668 CPU clock: %d MHz\n", 2*mips_hpt_frequency / 1000000);
+	sys_clk = clk_get(NULL, "sys");
+	if (IS_ERR(sys_clk))
+		panic("unable to get system clock\n");
+
+	mips_hpt_frequency = clk_get_rate(sys_clk) / 2;
 }
 

target/linux/adm8668/files/arch/mips/include/asm/mach-adm8668/adm8668.h

@@ -109,4 +109,6 @@
 #define CRGPIO_TOGGLE(num)	\
 	ADM8668_CONFIG_REG(CRGPIO_REG) ^= (1 << (6 + num))
 
+void adm8668_init_clocks(void);
+
 #endif /* __ADM8668_H__ */