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>
diff --git a/arch/arm/mach-s3c2410/Kconfig b/arch/arm/mach-s3c2410/Kconfig
index 41bb65d..a7f70e1 100644
--- a/arch/arm/mach-s3c2410/Kconfig
+++ b/arch/arm/mach-s3c2410/Kconfig
@@ -12,6 +12,7 @@
select S3C2410_GPIO
select CPU_LLSERIAL_S3C2410
select S3C2410_PM if PM
+ select S3C2410_CPUFREQ if CPU_FREQ_S3C24XX
help
Support for S3C2410 and S3C2410A family from the S3C24XX line
of Samsung Mobile CPUs.
@@ -45,6 +46,15 @@
Internal node for machines with an BAST style IDE
interface
+# cpu frequency scaling support
+
+config S3C2410_CPUFREQ
+ bool
+ depends on CPU_FREQ_S3C24XX && CPU_S3C2410
+ select S3C2410_CPUFREQ_UTILS
+ help
+ CPU Frequency scaling support for S3C2410
+
menu "S3C2410 Machines"
config ARCH_SMDK2410
@@ -79,6 +89,7 @@
config ARCH_BAST
bool "Simtec Electronics BAST (EB2410ITX)"
select CPU_S3C2410
+ select S3C2410_IOTIMING if S3C2410_CPUFREQ
select PM_SIMTEC if PM
select SIMTEC_NOR
select MACH_BAST_IDE
diff --git a/arch/arm/mach-s3c2410/Makefile b/arch/arm/mach-s3c2410/Makefile
index fca02f8..cc25eb0 100644
--- a/arch/arm/mach-s3c2410/Makefile
+++ b/arch/arm/mach-s3c2410/Makefile
@@ -15,6 +15,7 @@
obj-$(CONFIG_CPU_S3C2410_DMA) += dma.o
obj-$(CONFIG_S3C2410_PM) += pm.o sleep.o
obj-$(CONFIG_S3C2410_GPIO) += gpio.o
+obj-$(CONFIG_S3C2410_CPUFREQ) += cpu-freq.o
# Machine support
diff --git a/arch/arm/mach-s3c2410/cpu-freq.c b/arch/arm/mach-s3c2410/cpu-freq.c
new file mode 100644
index 0000000..f2cbdba
--- /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);
diff --git a/arch/arm/plat-s3c24xx/Kconfig b/arch/arm/plat-s3c24xx/Kconfig
index d82d30c..a547c79 100644
--- a/arch/arm/plat-s3c24xx/Kconfig
+++ b/arch/arm/plat-s3c24xx/Kconfig
@@ -116,6 +116,13 @@
Internal node to select io timing code that is common to the s3c2410
and s3c2440/s3c2442 cpu frequency support.
+config S3C2410_CPUFREQ_UTILS
+ bool
+ depends on CPU_FREQ_S3C24XX
+ help
+ Internal node to select timing code that is common to the s3c2410
+ and s3c2440/s3c244 cpu frequency support.
+
config MACH_SMDK
bool
help
diff --git a/arch/arm/plat-s3c24xx/Makefile b/arch/arm/plat-s3c24xx/Makefile
index 6f9afd1..b28fe9c 100644
--- a/arch/arm/plat-s3c24xx/Makefile
+++ b/arch/arm/plat-s3c24xx/Makefile
@@ -36,6 +36,7 @@
obj-$(CONFIG_S3C2410_DMA) += dma.o
obj-$(CONFIG_S3C24XX_ADC) += adc.o
obj-$(CONFIG_S3C2410_IOTIMING) += s3c2410-iotiming.o
+obj-$(CONFIG_S3C2410_CPUFREQ_UTILS) += s3c2410-cpufreq-utils.o
# device specific setup and/or initialisation
obj-$(CONFIG_ARCH_S3C2410) += setup-i2c.o
diff --git a/arch/arm/plat-s3c24xx/s3c2410-cpufreq-utils.c b/arch/arm/plat-s3c24xx/s3c2410-cpufreq-utils.c
new file mode 100644
index 0000000..43ea801
--- /dev/null
+++ b/arch/arm/plat-s3c24xx/s3c2410-cpufreq-utils.c
@@ -0,0 +1,64 @@
+/* linux/arch/arm/plat-s3c24xx/s3c2410-cpufreq-utils.c
+ *
+ * Copyright (c) 2009 Simtec Electronics
+ * http://armlinux.simtec.co.uk/
+ * Ben Dooks <ben@simtec.co.uk>
+ *
+ * S3C24XX CPU Frequency scaling - utils for S3C2410/S3C2440/S3C2442
+ *
+ * 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/errno.h>
+#include <linux/cpufreq.h>
+#include <linux/io.h>
+
+#include <mach/map.h>
+#include <mach/regs-mem.h>
+#include <mach/regs-clock.h>
+
+#include <plat/cpu-freq-core.h>
+
+/**
+ * s3c2410_cpufreq_setrefresh - set SDRAM refresh value
+ * @cfg: The frequency configuration
+ *
+ * Set the SDRAM refresh value appropriately for the configured
+ * frequency.
+ */
+void s3c2410_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg)
+{
+ struct s3c_cpufreq_board *board = cfg->board;
+ unsigned long refresh;
+ unsigned long refval;
+
+ /* Reduce both the refresh time (in ns) and the frequency (in MHz)
+ * down to ensure that we do not overflow 32 bit numbers.
+ *
+ * This should work for HCLK up to 133MHz and refresh period up
+ * to 30usec.
+ */
+
+ refresh = (cfg->freq.hclk / 100) * (board->refresh / 10);
+ refresh = DIV_ROUND_UP(refresh, (1000 * 1000)); /* apply scale */
+ refresh = (1 << 11) + 1 - refresh;
+
+ s3c_freq_dbg("%s: refresh value %lu\n", __func__, refresh);
+
+ refval = __raw_readl(S3C2410_REFRESH);
+ refval &= ~((1 << 12) - 1);
+ refval |= refresh;
+ __raw_writel(refval, S3C2410_REFRESH);
+}
+
+/**
+ * s3c2410_set_fvco - set the PLL value
+ * @cfg: The frequency configuration
+ */
+void s3c2410_set_fvco(struct s3c_cpufreq_config *cfg)
+{
+ __raw_writel(cfg->pll.index, S3C2410_MPLLCON);
+}