--- /dev/null
+/*
+ * arch/arm/mach-ep93xx/clock.c
+ * Clock control for Cirrus EP93xx chips.
+ *
+ * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/string.h>
+#include <asm/div64.h>
+#include <asm/hardware.h>
+#include <asm/io.h>
+
+struct clk {
+ char *name;
+ unsigned long rate;
+ int users;
+ u32 enable_reg;
+ u32 enable_mask;
+};
+
+static struct clk clk_pll1 = {
+ .name = "pll1",
+};
+static struct clk clk_f = {
+ .name = "fclk",
+};
+static struct clk clk_h = {
+ .name = "hclk",
+};
+static struct clk clk_p = {
+ .name = "pclk",
+};
+static struct clk clk_pll2 = {
+ .name = "pll2",
+};
+static struct clk clk_usb_host = {
+ .name = "usb_host",
+ .enable_reg = EP93XX_SYSCON_CLOCK_CONTROL,
+ .enable_mask = EP93XX_SYSCON_CLOCK_USH_EN,
+};
+
+
+static struct clk *clocks[] = {
+ &clk_pll1,
+ &clk_f,
+ &clk_h,
+ &clk_p,
+ &clk_pll2,
+ &clk_usb_host,
+};
+
+struct clk *clk_get(struct device *dev, const char *id)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(clocks); i++) {
+ if (!strcmp(clocks[i]->name, id))
+ return clocks[i];
+ }
+
+ return ERR_PTR(-ENOENT);
+}
+
+int clk_enable(struct clk *clk)
+{
+ if (!clk->users++ && clk->enable_reg) {
+ u32 value;
+
+ value = __raw_readl(clk->enable_reg);
+ __raw_writel(value | clk->enable_mask, clk->enable_reg);
+ }
+
+ return 0;
+}
+
+void clk_disable(struct clk *clk)
+{
+ if (!--clk->users && clk->enable_reg) {
+ u32 value;
+
+ value = __raw_readl(clk->enable_reg);
+ __raw_writel(value & ~clk->enable_mask, clk->enable_reg);
+ }
+}
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+ return clk->rate;
+}
+
+void clk_put(struct clk *clk)
+{
+}
+
+
+
+static char fclk_divisors[] = { 1, 2, 4, 8, 16, 1, 1, 1 };
+static char hclk_divisors[] = { 1, 2, 4, 5, 6, 8, 16, 32 };
+static char pclk_divisors[] = { 1, 2, 4, 8 };
+
+/*
+ * PLL rate = 14.7456 MHz * (X1FBD + 1) * (X2FBD + 1) / (X2IPD + 1) / 2^PS
+ */
+static unsigned long calc_pll_rate(u32 config_word)
+{
+ unsigned long long rate;
+ int i;
+
+ rate = 14745600;
+ rate *= ((config_word >> 11) & 0x1f) + 1; /* X1FBD */
+ rate *= ((config_word >> 5) & 0x3f) + 1; /* X2FBD */
+ do_div(rate, (config_word & 0x1f) + 1); /* X2IPD */
+ for (i = 0; i < ((config_word >> 16) & 3); i++) /* PS */
+ rate >>= 1;
+
+ return (unsigned long)rate;
+}
+
+void ep93xx_clock_init(void)
+{
+ u32 value;
+
+ value = __raw_readl(EP93XX_SYSCON_CLOCK_SET1);
+ if (!(value & 0x00800000)) { /* PLL1 bypassed? */
+ clk_pll1.rate = 14745600;
+ } else {
+ clk_pll1.rate = calc_pll_rate(value);
+ }
+ clk_f.rate = clk_pll1.rate / fclk_divisors[(value >> 25) & 0x7];
+ clk_h.rate = clk_pll1.rate / hclk_divisors[(value >> 20) & 0x7];
+ clk_p.rate = clk_h.rate / pclk_divisors[(value >> 18) & 0x3];
+
+ value = __raw_readl(EP93XX_SYSCON_CLOCK_SET2);
+ if (!(value & 0x00080000)) { /* PLL2 bypassed? */
+ clk_pll2.rate = 14745600;
+ } else if (value & 0x00040000) { /* PLL2 enabled? */
+ clk_pll2.rate = calc_pll_rate(value);
+ } else {
+ clk_pll2.rate = 0;
+ }
+ clk_usb_host.rate = clk_pll2.rate / (((value >> 28) & 0xf) + 1);
+
+ printk(KERN_INFO "ep93xx: PLL1 running at %ld MHz, PLL2 at %ld MHz\n",
+ clk_pll1.rate / 1000000, clk_pll2.rate / 1000000);
+ printk(KERN_INFO "ep93xx: FCLK %ld MHz, HCLK %ld MHz, PCLK %ld MHz\n",
+ clk_f.rate / 1000000, clk_h.rate / 1000000,
+ clk_p.rate / 1000000);
+}
projects / linux-2.6 / commitdiff