MIPS: AR7: Implement clock API

This patch makes the ar7 clock code implement the Linux clk API. Drivers
using the various clocks available in the SoC are updated accordingly.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Wim Van Sebroeck <wim@iguana.be>
To: linux-mips@linux-mips.org
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: netdev@vger.kernel.org
Cc: David Miller <davem@davemloft.net>
Patchwork: http://patchwork.linux-mips.org/patch/881/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/drivers/watchdog/ar7_wdt.c b/drivers/watchdog/ar7_wdt.c
index 2e94b71..2bb95cd 100644
--- a/drivers/watchdog/ar7_wdt.c
+++ b/drivers/watchdog/ar7_wdt.c
@@ -34,6 +34,7 @@
 #include <linux/ioport.h>
 #include <linux/io.h>
 #include <linux/uaccess.h>
+#include <linux/clk.h>
 
 #include <asm/addrspace.h>
 #include <asm/mach-ar7/ar7.h>
@@ -80,6 +81,8 @@
 /* Pointer to the remapped WDT IO space */
 static struct ar7_wdt *ar7_wdt;
 
+static struct clk *vbus_clk;
+
 static void ar7_wdt_kick(u32 value)
 {
 	WRITE_REG(ar7_wdt->kick_lock, 0x5555);
@@ -138,17 +141,19 @@
 static void ar7_wdt_update_margin(int new_margin)
 {
 	u32 change;
+	u32 vbus_rate;
 
-	change = new_margin * (ar7_vbus_freq() / prescale_value);
+	vbus_rate = clk_get_rate(vbus_clk);
+	change = new_margin * (vbus_rate / prescale_value);
 	if (change < 1)
 		change = 1;
 	if (change > 0xffff)
 		change = 0xffff;
 	ar7_wdt_change(change);
-	margin = change * prescale_value / ar7_vbus_freq();
+	margin = change * prescale_value / vbus_rate;
 	printk(KERN_INFO DRVNAME
 	       ": timer margin %d seconds (prescale %d, change %d, freq %d)\n",
-	       margin, prescale_value, change, ar7_vbus_freq());
+	       margin, prescale_value, change, vbus_rate);
 }
 
 static void ar7_wdt_enable_wdt(void)
@@ -298,6 +303,13 @@
 		goto out_mem_region;
 	}
 
+	vbus_clk = clk_get(NULL, "vbus");
+	if (IS_ERR(vbus_clk)) {
+		printk(KERN_ERR DRVNAME ": could not get vbus clock\n");
+		rc = PTR_ERR(vbus_clk);
+		goto out_mem_region;
+	}
+
 	ar7_wdt_disable_wdt();
 	ar7_wdt_prescale(prescale_value);
 	ar7_wdt_update_margin(margin);