ARM: OMAP: implement CPUfreq frequency table based on PRCM table

PATCH In review Kevin Hilman 2 participants 4 messages Nov 15, 2007 – Nov 16, 2007

Subsystems (4)

Arm (32-bit) Arm sub-architectures OMAP2+ support OMAP clock framework support

lore

Share & tools

lore

Kevin Hilman

author

2007-11-15 23:38 UTC #0 lore raw

PATCH 1/1 ARM: OMAP: implement CPUfreq frequency table based on PRCM table

This patch adds a CPUfreq frequency-table implementation for OMAP2 by walking the PRCM rate-table for available entries and adding them to a CPUfreq table.

CPUfreq can then be used to manage switching between all the available entries in the PRCM rate table. Either use the CPUfreq sysfs interface directly, (see Section 3 of Documentation/cpu-freq/user-guide.txt) or use the cpufrequtils package:
http://www.kernel.org/pub/linux/utils/kernel/cpufreq/cpufrequtils.html

Signed-off-by Kevin Hilman <[email protected]>

---
 arch/arm/mach-omap2/clock24xx.c |   37 ++++++++++++++++++++++++++++
 arch/arm/plat-omap/cpu-omap.c   |   52 ++++++++++++++++++++++++++++++++++++++--
 2 files changed, 87 insertions(+), 2 deletions(-)

arch/arm/mach-omap2/clock24xx.c +37 -0

Index: dev/arch/arm/mach-omap2/clock24xx.c
===================================================================
@@ -26,6 +26,7 @@
 #include <linux/clk.h>
 
 #include <linux/io.h>
+#include <linux/cpufreq.h>
 
 #include <asm/arch/clock.h>
 #include <asm/arch/sram.h>

@@ -461,6 +462,42 @@ static int __init omap2_clk_arch_init(vo
 }
 arch_initcall(omap2_clk_arch_init);
 
+#ifdef CONFIG_CPU_FREQ
+/*
+ * Walk PRCM rate table and fillout cpufreq freq_table
+ */
+static struct cpufreq_frequency_table freq_table[ARRAY_SIZE(rate_table)];
+
+void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
+{
+	struct prcm_config *prcm;
+	int i = 0;
+
+	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
+		if (!(prcm->flags & cpu_mask))
+			continue;
+		if (prcm->xtal_speed != sys_ck.rate)
+			continue;
+
+		/* don't put bypass rates in table */
+		if (prcm->dpll_speed == prcm->xtal_speed)
+			continue;
+
+		freq_table[i].index = i;
+		freq_table[i].frequency = prcm->mpu_speed / 1000;
+		i++;
+	}
+
+	freq_table[i].index = i;
+	freq_table[i].frequency = CPUFREQ_TABLE_END;
+
+	*table = &freq_table[0];
+}
+#else
+void clk_init_cpufreq_table(struct cpufreq_frequency_table **table) { }
+#endif
+EXPORT_SYMBOL(clk_init_cpufreq_table);
+
 int __init omap2_clk_init(void)
 {
 	struct prcm_config *prcm;

arch/arm/plat-omap/cpu-omap.c +50 -2

117 lines not on this page · raw message

Tony Lindgren

maintainer

2007-11-16 19:54 UTC #1 lore raw

Hi,

Quoted 3 lines · Kevin Hilman

This patch adds a CPUfreq frequency-table implementation for OMAP2 by walking the PRCM rate-table for available entries and adding them to a CPUfreq table.

I updated the patch a bit to use the cpufreq table if initialized, and to allow omap1 and omap3 to implement it later on easily. Can you please check? I've only compile tested on osk, and on n800 noticed there are currently no frequencies for 19.2 source clock.

Regards,

Tony

From: Kevin Hilman <[email protected]>
Subject: [PATCH] ARM: OMAP: implement CPUfreq frequency table based on PRCM table

This patch adds a CPUfreq frequency-table implementation for OMAP2 by walking the PRCM rate-table for available entries and adding them to a CPUfreq table.

Signed-off-by Kevin Hilman <[email protected]>

Updated to try to use cpufreq_table if it exists.

Signed-off-by Tony Lindgren <[email protected]>

arch/arm/mach-omap2/clock24xx.c +43 -0

@@ -26,6 +26,7 @@
 #include <linux/clk.h>
 
 #include <linux/io.h>
+#include <linux/cpufreq.h>
 
 #include <asm/arch/clock.h>
 #include <asm/arch/sram.h>

@@ -374,6 +375,45 @@ static int omap2_select_table_rate(struct clk *clk, unsigned long rate)
 	return 0;
 }
 
+#ifdef CONFIG_CPU_FREQ
+/*
+ * Walk PRCM rate table and fillout cpufreq freq_table
+ */
+static struct cpufreq_frequency_table freq_table[ARRAY_SIZE(rate_table)];
+
+void omap2_clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
+{
+	struct prcm_config *prcm;
+	int i = 0;
+
+	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
+		if (!(prcm->flags & cpu_mask))
+			continue;
+		if (prcm->xtal_speed != sys_ck.rate)
+			continue;
+
+		/* don't put bypass rates in table */
+		if (prcm->dpll_speed == prcm->xtal_speed)
+			continue;
+
+		freq_table[i].index = i;
+		freq_table[i].frequency = prcm->mpu_speed / 1000;
+		i++;
+	}
+
+	if (i == 0) {
+		printk(KERN_WARNING "%s: failed to initialize frequency table\n",
+		       __FUNCTION__);
+		return;
+	}
+
+	freq_table[i].index = i;
+	freq_table[i].frequency = CPUFREQ_TABLE_END;
+
+	*table = &freq_table[0];
+}
+#endif
+
 static struct clk_functions omap2_clk_functions = {
 	.clk_enable		= omap2_clk_enable,
 	.clk_disable		= omap2_clk_disable,

@@ -381,6 +421,9 @@ static struct clk_functions omap2_clk_functions = {
 	.clk_set_rate		= omap2_clk_set_rate,
 	.clk_set_parent		= omap2_clk_set_parent,
 	.clk_disable_unused	= omap2_clk_disable_unused,
+#ifdef	CONFIG_CPU_FREQ
+	.clk_init_cpufreq_table	= omap2_clk_init_cpufreq_table,
+#endif
 };
 
 static u32 omap2_get_apll_clkin(void)

arch/arm/plat-omap/clock.c +13 -0

@@ -394,6 +394,19 @@ void clk_enable_init_clocks(void)
 }
 EXPORT_SYMBOL(clk_enable_init_clocks);
 
+#ifdef CONFIG_CPU_FREQ
+void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&clockfw_lock, flags);
+	if (arch_clock->clk_init_cpufreq_table)
+		arch_clock->clk_init_cpufreq_table(table);
+	spin_unlock_irqrestore(&clockfw_lock, flags);
+}
+EXPORT_SYMBOL(clk_init_cpufreq_table);
+#endif
+
 /*-------------------------------------------------------------------------*/
 
 #ifdef CONFIG_OMAP_RESET_CLOCKS

arch/arm/plat-omap/cpu-omap.c +53 -4

111 lines not on this page · raw message

include/asm-arm/arch-omap/clock.h +8 -0

@@ -10,6 +10,8 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/cpufreq.h>
+
 #ifndef __ARCH_ARM_OMAP_CLOCK_H
 #define __ARCH_ARM_OMAP_CLOCK_H

@@ -85,6 +87,9 @@ struct clk_functions {
 	void		(*clk_allow_idle)(struct clk *clk);
 	void		(*clk_deny_idle)(struct clk *clk);
 	void		(*clk_disable_unused)(struct clk *clk);
+#ifdef	CONFIG_CPU_FREQ
+	void		(*clk_init_cpufreq_table)(struct cpufreq_frequency_table **table);
+#endif
 };
 
 extern unsigned int mpurate;

@@ -99,6 +104,9 @@ extern void clk_allow_idle(struct clk *clk);
 extern void clk_deny_idle(struct clk *clk);
 extern int clk_get_usecount(struct clk *clk);
 extern void clk_enable_init_clocks(void);
+#ifdef CONFIG_CPU_FREQ
+extern void clk_init_cpufreq_table(struct cpufreq_frequency_table **table);
+#endif
 
 /* Clock flags */
 #define RATE_CKCTL		(1 << 0)	/* Main fixed ratio clocks */

Kevin Hilman

author

2007-11-16 23:29 UTC #2 lore raw

Quoted 8 lines · Tony Lindgren

Quoted 3 lines · Kevin Hilman
This patch adds a CPUfreq frequency-table implementation for OMAP2 by walking the PRCM rate-table for available entries and adding them to a CPUfreq table.
I updated the patch a bit to use the cpufreq table if initialized, and to allow omap1 and omap3 to implement it later on easily. Can you please check?

I like it. Thanks.

Quoted 2 lines

I've only compile tested on osk, and on n800 noticed there are currently no frequencies for 19.2 source clock.

I tested cpufreq on 2430 and it looks good.

I'll be adding the 3430 support shortly as well, so your updates are cleaner for that.

Kevin

Tony Lindgren

maintainer

2007-11-16 23:40 UTC #3 lore raw

Quoted 8 lines · Kevin Hilman

Quoted 5 lines · Tony Lindgren
Quoted 3 lines · Kevin Hilman
This patch adds a CPUfreq frequency-table implementation for OMAP2 by walking the PRCM rate-table for available entries and adding them to a CPUfreq table.

Quoted 5 lines

Quoted 3 lines
I updated the patch a bit to use the cpufreq table if initialized, and to allow omap1 and omap3 to implement it later on easily. Can you please check?
I like it. Thanks.

Cool.

Quoted 4 lines

Quoted 2 lines
I've only compile tested on osk, and on n800 noticed there are currently no frequencies for 19.2 source clock.
I tested cpufreq on 2430 and it looks good.

OK, will push today then.

Quoted 2 lines

I'll be adding the 3430 support shortly as well, so your updates are cleaner for that.

Tony