[PATCH V2 44/69] SPEAr CPU freq: Adding support for CPU Freq framework
Viresh KUMAR
viresh.kumar at st.com
Fri Oct 1 07:56:04 EDT 2010
From: Deepak Sikri <deepak.sikri at st.com>
Signed-off-by: Deepak Sikri <deepak.sikri at st.com>
Signed-off-by: Rajeev Kumar <rajeev-dlh.kumar at st.com>
Signed-off-by: shiraz hashim <shiraz.hashim at st.com>
Signed-off-by: Viresh Kumar <viresh.kumar at st.com>
---
arch/arm/Kconfig | 1 +
arch/arm/mach-spear13xx/clock.c | 1 +
arch/arm/mach-spear3xx/clock.c | 1 +
arch/arm/mach-spear6xx/clock.c | 1 +
arch/arm/plat-spear/Makefile | 2 +-
arch/arm/plat-spear/cpufreq.c | 159 +++++++++++++++++++++++++++++++++++++++
6 files changed, 164 insertions(+), 1 deletions(-)
create mode 100644 arch/arm/plat-spear/cpufreq.c
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 158bf06..cdd0a2b 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -821,6 +821,7 @@ config PLAT_SPEAR
select COMMON_CLKDEV
select GENERIC_CLOCKEVENTS
select HAVE_CLK
+ select ARCH_HAS_CPUFREQ
help
Support for ST's SPEAr platform (SPEAr3xx, SPEAr6xx and SPEAr13xx).
diff --git a/arch/arm/mach-spear13xx/clock.c b/arch/arm/mach-spear13xx/clock.c
index 4f320fa..79942a9 100644
--- a/arch/arm/mach-spear13xx/clock.c
+++ b/arch/arm/mach-spear13xx/clock.c
@@ -91,6 +91,7 @@ static struct pll_clk_config pll1_config = {
/* pll rate configuration table, in ascending order of rates */
struct pll_rate_tbl pll_rtbl[] = {
/* PCLK 24MHz */
+ {.mode = 0, .m = 0x64, .n = 0x03, .p = 0x2}, /* 400 MHz */
{.mode = 0, .m = 0x7D, .n = 0x03, .p = 0x2}, /* 500 MHz */
{.mode = 0, .m = 0xA6, .n = 0x03, .p = 0x2}, /* 664 MHz */
{.mode = 0, .m = 0xC8, .n = 0x03, .p = 0x2}, /* 800 MHz */
diff --git a/arch/arm/mach-spear3xx/clock.c b/arch/arm/mach-spear3xx/clock.c
index 4f049fe..64d9cdc 100644
--- a/arch/arm/mach-spear3xx/clock.c
+++ b/arch/arm/mach-spear3xx/clock.c
@@ -55,6 +55,7 @@ static struct pll_clk_masks pll_masks = {
/* pll rate configuration table, in ascending order of rates */
struct pll_rate_tbl pll_rtbl[] = {
+ {.mode = 0, .m = 0x53, .n = 0x0C, .p = 0x1}, /* 166 MHz */
{.mode = 0, .m = 0x85, .n = 0x0C, .p = 0x1}, /* 266 MHz */
{.mode = 0, .m = 0xA6, .n = 0x0C, .p = 0x1}, /* 332 MHz */
};
diff --git a/arch/arm/mach-spear6xx/clock.c b/arch/arm/mach-spear6xx/clock.c
index 99cc21d..f1429f5 100644
--- a/arch/arm/mach-spear6xx/clock.c
+++ b/arch/arm/mach-spear6xx/clock.c
@@ -55,6 +55,7 @@ static struct pll_clk_masks pll_masks = {
/* pll rate configuration table, in ascending order of rates */
struct pll_rate_tbl pll_rtbl[] = {
+ {.mode = 0, .m = 0x53, .n = 0x0C, .p = 0x1}, /* 166 MHz */
{.mode = 0, .m = 0x85, .n = 0x0C, .p = 0x1}, /* 266 MHz */
{.mode = 0, .m = 0xA6, .n = 0x0C, .p = 0x1}, /* 332 MHz */
};
diff --git a/arch/arm/plat-spear/Makefile b/arch/arm/plat-spear/Makefile
index 1c8ee4a..c25e5b8 100644
--- a/arch/arm/plat-spear/Makefile
+++ b/arch/arm/plat-spear/Makefile
@@ -6,7 +6,7 @@
obj-y := clcd.o clock.o pll_clk.o smi.o time.o
obj-$(CONFIG_ARCH_SPEAR3XX) += shirq.o padmux.o
-
+obj-$(CONFIG_CPU_FREQ) += cpufreq.o
obj-$(CONFIG_MACH_SPEAR310) += plgpio.o
obj-$(CONFIG_MACH_SPEAR320) += plgpio.o
obj-$(CONFIG_SPEAR_PWM) += pwm.o
diff --git a/arch/arm/plat-spear/cpufreq.c b/arch/arm/plat-spear/cpufreq.c
new file mode 100644
index 0000000..9384d65
--- /dev/null
+++ b/arch/arm/plat-spear/cpufreq.c
@@ -0,0 +1,159 @@
+/*
+ * arch/arm/plat-spear/cpufreq.c
+ *
+ * CPU Frequency Scaling for SPEAr platform
+ *
+ * Copyright (C) 2010 ST Microelectronics
+ * Deepak Sikri<deepak.sikri at st.com>
+ *
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/cpufreq.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <asm/system.h>
+#include <mach/hardware.h>
+
+#define CPU_CLK "cpu_clk"
+
+#ifdef CONFIG_ARCH_SPEAR13XX
+#define MIN_CPU_FREQ 200000
+#define MAX_CPU_FREQ 500000
+
+static u32 spear_cpu_freq[] = {
+ 200000, /* 200 MHZ */
+ 250000, /* 250 MHZ */
+ 332000, /* 332 MHZ */
+ 400000, /* 400 MHZ */
+ 500000, /* 500 MHZ */
+};
+#elif defined(CONFIG_ARCH_SPEAR6XX) || defined(CONFIG_ARCH_SPEAR3XX)
+#define MIN_CPU_FREQ 166000
+#define MAX_CPU_FREQ 332000
+
+static u32 spear_cpu_freq[] = {
+ 166000, /* 166 MHZ */
+ 266000, /* 266 MHZ */
+ 332000, /* 333 MHZ */
+};
+#endif
+
+static struct
+ cpufreq_frequency_table spear_freq_tbl[ARRAY_SIZE(spear_cpu_freq) + 1];
+static struct clk *cpu_clk;
+
+int spear_cpufreq_verify(struct cpufreq_policy *policy)
+{
+ return cpufreq_frequency_table_verify(policy, spear_freq_tbl);
+}
+
+unsigned int spear_cpufreq_get(unsigned int cpu)
+{
+ unsigned long rate;
+
+ if (cpu)
+ return 0;
+
+ rate = clk_get_rate(cpu_clk) / 1000;
+ return rate;
+}
+
+static int spear_cpufreq_target(struct cpufreq_policy *policy,
+ unsigned int target_freq, unsigned int relation)
+{
+ struct cpufreq_freqs freqs;
+ int ret = 0;
+ int index;
+
+ if (policy->cpu != 0)
+ return -EINVAL;
+
+ if (cpufreq_frequency_table_target(policy, spear_freq_tbl,
+ target_freq, relation, &index))
+ return -EINVAL;
+
+ freqs.old = spear_cpufreq_get(0);
+ freqs.new = spear_cpu_freq[index];
+ freqs.cpu = policy->cpu;
+
+ if (freqs.old == target_freq)
+ return 0;
+
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+ ret = clk_set_rate(cpu_clk, freqs.new * 1000);
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+
+ return ret;
+}
+
+static int spear_cpufreq_init(struct cpufreq_policy *policy)
+{
+ int result;
+ int i = 0;
+
+ if (policy->cpu != 0)
+ return -EINVAL;
+
+ cpu_clk = clk_get(NULL, CPU_CLK);
+ if (IS_ERR(cpu_clk))
+ return PTR_ERR(cpu_clk);
+
+ policy->cpuinfo.min_freq = MIN_CPU_FREQ;
+ policy->cpuinfo.max_freq = MAX_CPU_FREQ;
+ policy->cur = policy->min = policy->max = spear_cpufreq_get(0);
+
+ for (i = 0; i < ARRAY_SIZE(spear_cpu_freq); i++) {
+ spear_freq_tbl[i].index = i;
+ spear_freq_tbl[i].frequency = spear_cpu_freq[i];
+ }
+
+ spear_freq_tbl[i].index = i;
+ spear_freq_tbl[i].frequency = CPUFREQ_TABLE_END;
+ result = cpufreq_frequency_table_cpuinfo(policy, spear_freq_tbl);
+ if (!result)
+ cpufreq_frequency_table_get_attr(spear_freq_tbl,
+ policy->cpu);
+
+ policy->cpuinfo.transition_latency = 300*1000; /*250 uS*/
+
+ return 0;
+}
+
+static int spear_cpufreq_exit(struct cpufreq_policy *policy)
+{
+ clk_put(cpu_clk);
+ return 0;
+}
+
+static struct freq_attr *spear_cpufreq_attr[] = {
+ &cpufreq_freq_attr_scaling_available_freqs,
+ NULL,
+};
+
+static struct cpufreq_driver spear_driver = {
+ .flags = CPUFREQ_STICKY,
+ .verify = spear_cpufreq_verify,
+ .target = spear_cpufreq_target,
+ .get = spear_cpufreq_get,
+ .init = spear_cpufreq_init,
+ .exit = spear_cpufreq_exit,
+ .name = "spear_cpufreq",
+ .attr = spear_cpufreq_attr,
+};
+
+static int __init spear_cpufreq_register(void)
+{
+ return cpufreq_register_driver(&spear_driver);
+}
+
+arch_initcall(spear_cpufreq_register);
--
1.7.2.2
More information about the linux-arm-kernel
mailing list