ARM: S3C2410: CPUFREQ: Add core support.

Add core support for frequency scaling on the S3C2410 SoC.

Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

1 files changed, 157 insertions, 0 deletions

diff --git a/arch/arm/mach-s3c2410/cpu-freq.c b/arch/arm/mach-s3c2410/cpu-freq.c
new file mode 100644
index 00000000000..f2cbdbab0df
--- /dev/null
+++ b/arch/arm/mach-s3c2410/cpu-freq.c
@@ -0,0 +1,157 @@
+/* linux/arch/arm/mach-s3c2410/cpu-freq.c
+ *
+ * Copyright (c) 2006,2008 Simtec Electronics
+ *	http://armlinux.simtec.co.uk/
+ *	Ben Dooks <ben@simtec.co.uk>
+ *
+ * S3C2410 CPU Frequency scaling
+ *
+ * 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/init.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/cpufreq.h>
+#include <linux/sysdev.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#include <asm/mach/arch.h>
+#include <asm/mach/map.h>
+
+#include <mach/regs-clock.h>
+
+#include <plat/cpu.h>
+#include <plat/clock.h>
+#include <plat/cpu-freq-core.h>
+
+/* Note, 2410A has an extra mode for 1:4:4 ratio, bit 2 of CLKDIV */
+
+static void s3c2410_cpufreq_setdivs(struct s3c_cpufreq_config *cfg)
+{
+	u32 clkdiv = 0;
+
+	if (cfg->divs.h_divisor == 2)
+		clkdiv |= S3C2410_CLKDIVN_HDIVN;
+
+	if (cfg->divs.p_divisor != cfg->divs.h_divisor)
+		clkdiv |= S3C2410_CLKDIVN_PDIVN;
+
+	__raw_writel(clkdiv, S3C2410_CLKDIVN);
+}
+
+static int s3c2410_cpufreq_calcdivs(struct s3c_cpufreq_config *cfg)
+{
+	unsigned long hclk, fclk, pclk;
+	unsigned int hdiv, pdiv;
+	unsigned long hclk_max;
+
+	fclk = cfg->freq.fclk;
+	hclk_max = cfg->max.hclk;
+
+	cfg->freq.armclk = fclk;
+
+	s3c_freq_dbg("%s: fclk is %lu, max hclk %lu\n",
+		      __func__, fclk, hclk_max);
+
+	hdiv = (fclk > cfg->max.hclk) ? 2 : 1;
+	hclk = fclk / hdiv;
+
+	if (hclk > cfg->max.hclk) {
+		s3c_freq_dbg("%s: hclk too big\n", __func__);
+		return -EINVAL;
+	}
+
+	pdiv = (hclk > cfg->max.pclk) ? 2 : 1;
+	pclk = hclk / pdiv;
+
+	if (pclk > cfg->max.pclk) {
+		s3c_freq_dbg("%s: pclk too big\n", __func__);
+		return -EINVAL;
+	}
+
+	pdiv *= hdiv;
+
+	/* record the result */
+	cfg->divs.p_divisor = pdiv;
+	cfg->divs.h_divisor = hdiv;
+
+	return 0      ;
+}
+
+static struct s3c_cpufreq_info s3c2410_cpufreq_info = {
+	.max		= {
+		.fclk	= 200000000,
+		.hclk	= 100000000,
+		.pclk	=  50000000,
+	},
+
+	/* transition latency is about 5ms worst-case, so
+	 * set 10ms to be sure */
+	.latency	= 10000000,
+
+	.locktime_m	= 150,
+	.locktime_u	= 150,
+	.locktime_bits	= 12,
+
+	.need_pll	= 1,
+
+	.name		= "s3c2410",
+	.calc_iotiming	= s3c2410_iotiming_calc,
+	.set_iotiming	= s3c2410_iotiming_set,
+	.get_iotiming	= s3c2410_iotiming_get,
+	.resume_clocks	= s3c2410_setup_clocks,
+
+	.set_fvco	= s3c2410_set_fvco,
+	.set_refresh	= s3c2410_cpufreq_setrefresh,
+	.set_divs	= s3c2410_cpufreq_setdivs,
+	.calc_divs	= s3c2410_cpufreq_calcdivs,
+};
+
+static int s3c2410_cpufreq_add(struct sys_device *sysdev)
+{
+	return s3c_cpufreq_register(&s3c2410_cpufreq_info);
+}
+
+static struct sysdev_driver s3c2410_cpufreq_driver = {
+	.add		= s3c2410_cpufreq_add,
+};
+
+static int __init s3c2410_cpufreq_init(void)
+{
+	return sysdev_driver_register(&s3c2410_sysclass,
+				      &s3c2410_cpufreq_driver);
+}
+
+arch_initcall(s3c2410_cpufreq_init);
+
+static int s3c2410a_cpufreq_add(struct sys_device *sysdev)
+{
+	/* alter the maximum freq settings for S3C2410A. If a board knows
+	 * it only has a maximum of 200, then it should register its own
+	 * limits. */
+
+	s3c2410_cpufreq_info.max.fclk = 266000000;
+	s3c2410_cpufreq_info.max.hclk = 133000000;
+	s3c2410_cpufreq_info.max.pclk =  66500000;
+	s3c2410_cpufreq_info.name = "s3c2410a";
+
+	return s3c2410_cpufreq_add(sysdev);
+}
+
+static struct sysdev_driver s3c2410a_cpufreq_driver = {
+	.add		= s3c2410a_cpufreq_add,
+};
+
+static int __init s3c2410a_cpufreq_init(void)
+{
+	return sysdev_driver_register(&s3c2410a_sysclass,
+				      &s3c2410a_cpufreq_driver);
+}
+
+arch_initcall(s3c2410a_cpufreq_init);