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Diffstat (limited to 'arch/arm/cpu/arm920t/s3c24x0/speed.c')
-rw-r--r--arch/arm/cpu/arm920t/s3c24x0/speed.c98
1 files changed, 98 insertions, 0 deletions
diff --git a/arch/arm/cpu/arm920t/s3c24x0/speed.c b/arch/arm/cpu/arm920t/s3c24x0/speed.c
new file mode 100644
index 0000000000..b13283a798
--- /dev/null
+++ b/arch/arm/cpu/arm920t/s3c24x0/speed.c
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+/*
+ * (C) Copyright 2001-2004
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * (C) Copyright 2002
+ * David Mueller, ELSOFT AG, d.mueller@elsoft.ch
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/* This code should work for both the S3C2400 and the S3C2410
+ * as they seem to have the same PLL and clock machinery inside.
+ * The different address mapping is handled by the s3c24xx.h files below.
+ */
+
+#include <common.h>
+#ifdef CONFIG_S3C24X0
+
+#include <asm/io.h>
+#include <asm/arch/s3c24x0_cpu.h>
+
+#define MPLL 0
+#define UPLL 1
+
+/* ------------------------------------------------------------------------- */
+/* NOTE: This describes the proper use of this file.
+ *
+ * CONFIG_SYS_CLK_FREQ should be defined as the input frequency of the PLL.
+ *
+ * get_FCLK(), get_HCLK(), get_PCLK() and get_UCLK() return the clock of
+ * the specified bus in HZ.
+ */
+/* ------------------------------------------------------------------------- */
+
+static ulong get_PLLCLK(int pllreg)
+{
+ struct s3c24x0_clock_power *clk_power = s3c24x0_get_base_clock_power();
+ ulong r, m, p, s;
+
+ if (pllreg == MPLL)
+ r = readl(&clk_power->MPLLCON);
+ else if (pllreg == UPLL)
+ r = readl(&clk_power->UPLLCON);
+ else
+ hang();
+
+ m = ((r & 0xFF000) >> 12) + 8;
+ p = ((r & 0x003F0) >> 4) + 2;
+ s = r & 0x3;
+
+ return (CONFIG_SYS_CLK_FREQ * m) / (p << s);
+}
+
+/* return FCLK frequency */
+ulong get_FCLK(void)
+{
+ return get_PLLCLK(MPLL);
+}
+
+/* return HCLK frequency */
+ulong get_HCLK(void)
+{
+ struct s3c24x0_clock_power *clk_power = s3c24x0_get_base_clock_power();
+
+ return (readl(&clk_power->CLKDIVN) & 2) ? get_FCLK() / 2 : get_FCLK();
+}
+
+/* return PCLK frequency */
+ulong get_PCLK(void)
+{
+ struct s3c24x0_clock_power *clk_power = s3c24x0_get_base_clock_power();
+
+ return (readl(&clk_power->CLKDIVN) & 1) ? get_HCLK() / 2 : get_HCLK();
+}
+
+/* return UCLK frequency */
+ulong get_UCLK(void)
+{
+ return get_PLLCLK(UPLL);
+}
+
+#endif /* CONFIG_S3C24X0 */