IMX: introduce clock API

This patch introduces the clock API for i.MX and converts all
in-Kernel drivers to use it.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

diff --git a/arch/arm/mach-imx/cpufreq.c b/arch/arm/mach-imx/cpufreq.c
index e548ba7..be0809b 100644
--- a/arch/arm/mach-imx/cpufreq.c
+++ b/arch/arm/mach-imx/cpufreq.c
@@ -32,6 +32,8 @@
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/cpufreq.h>
+#include <linux/clk.h>
+#include <linux/err.h>
 #include <asm/system.h>
 
 #include <asm/hardware.h>
@@ -52,6 +54,8 @@
 static u32 mpctl0_at_boot;
 static u32 bclk_div_at_boot;
 
+static struct clk *system_clk, *mcu_clk;
+
 static void imx_set_async_mode(void)
 {
 	adjust_cr(CR_920T_CLOCK_MODE, CR_920T_ASYNC_MODE);
@@ -160,10 +164,10 @@
 	cr = get_cr();
 
 	if((cr & CR_920T_CLOCK_MODE) == CR_920T_FASTBUS_MODE) {
-		freq = imx_get_system_clk();
+		freq = clk_get_rate(system_clk);
 		freq = (freq + bclk_div/2) / bclk_div;
 	} else {
-		freq = imx_get_mcu_clk();
+		freq = clk_get_rate(mcu_clk);
 		if (cscr & CSCR_MPU_PRESC)
 			freq /= 2;
 	}
@@ -201,7 +205,7 @@
 	pr_debug(KERN_DEBUG "imx: requested frequency %ld Hz, mpctl0 at boot 0x%08x\n",
 			freq, mpctl0_at_boot);
 
-	sysclk = imx_get_system_clk();
+	sysclk = clk_get_rate(system_clk);
 
 	if (freq > sysclk / bclk_div_at_boot + 1000000) {
 		freq = imx_compute_mpctl(&mpctl0, mpctl0_at_boot, CLK32 * 512, freq, relation);
@@ -290,6 +294,16 @@
 	bclk_div_at_boot = __mfld2val(CSCR_BCLK_DIV, CSCR) + 1;
 	mpctl0_at_boot = 0;
 
+	system_clk = clk_get(NULL, "system_clk");
+	if (IS_ERR(system_clk))
+		return PTR_ERR(system_clk);
+
+	mcu_clk = clk_get(NULL, "mcu_clk");
+	if (IS_ERR(mcu_clk)) {
+		clk_put(system_clk);
+		return PTR_ERR(mcu_clk);
+	}
+
 	if((CSCR & CSCR_MPEN) &&
 	   ((get_cr() & CR_920T_CLOCK_MODE) != CR_920T_FASTBUS_MODE))
 		mpctl0_at_boot = MPCTL0;