ramips: implement clock API for RT288x

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@25125 3c298f89-4303-0410-b956-a3cf2f4a3e73

target/linux/ramips/files/arch/mips/ralink/rt288x/clock.c

@@ -0,0 +1,99 @@
+/*
+ *  Ralink RT288X clock API
+ *
+ *  Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+
+#include <asm/mach-ralink/common.h>
+#include <asm/mach-ralink/rt288x.h>
+#include <asm/mach-ralink/rt288x_regs.h>
+#include "common.h"
+
+struct clk {
+	unsigned long rate;
+};
+
+static struct clk rt288x_cpu_clk;
+static struct clk rt288x_sys_clk;
+static struct clk rt288x_wdt_clk;
+static struct clk rt288x_uart_clk;
+
+void __init rt288x_clocks_init(void)
+{
+	u32	t;
+
+	t = rt288x_sysc_rr(SYSC_REG_SYSTEM_CONFIG);
+	t = ((t >> SYSTEM_CONFIG_CPUCLK_SHIFT) & SYSTEM_CONFIG_CPUCLK_MASK);
+
+	switch (t) {
+	case SYSTEM_CONFIG_CPUCLK_250:
+		rt288x_cpu_clk.rate = 250000000;
+		break;
+	case SYSTEM_CONFIG_CPUCLK_266:
+		rt288x_cpu_clk.rate = 266666667;
+		break;
+	case SYSTEM_CONFIG_CPUCLK_280:
+		rt288x_cpu_clk.rate = 280000000;
+		break;
+	case SYSTEM_CONFIG_CPUCLK_300:
+		rt288x_cpu_clk.rate = 300000000;
+		break;
+	}
+
+	rt288x_sys_clk.rate = rt288x_cpu_clk.rate / 2;
+	rt288x_uart_clk.rate = rt288x_sys_clk.rate;
+	rt288x_wdt_clk.rate = rt288x_sys_clk.rate;
+}
+
+/*
+ * Linux clock API
+ */
+struct clk *clk_get(struct device *dev, const char *id)
+{
+	if (!strcmp(id, "sys"))
+		return &rt288x_sys_clk;
+
+	if (!strcmp(id, "cpu"))
+		return &rt288x_cpu_clk;
+
+	if (!strcmp(id, "wdt"))
+		return &rt288x_wdt_clk;
+
+	if (!strcmp(id, "uart"))
+		return &rt288x_uart_clk;
+
+	return ERR_PTR(-ENOENT);
+}
+EXPORT_SYMBOL(clk_get);
+
+int clk_enable(struct clk *clk)
+{
+	return 0;
+}
+EXPORT_SYMBOL(clk_enable);
+
+void clk_disable(struct clk *clk)
+{
+}
+EXPORT_SYMBOL(clk_disable);
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+	return clk->rate;
+}
+EXPORT_SYMBOL(clk_get_rate);
+
+void clk_put(struct clk *clk)
+{
+}
+EXPORT_SYMBOL(clk_put);