From: Kevin Hilman Date: Fri, 16 Nov 2007 23:44:18 +0000 (-0800) Subject: ARM: OMAP: implement CPUfreq frequency table based on PRCM table X-Git-Tag: v2.6.24-omap1~200 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=77ce544fa48deb7a2003f454624e3ca10d37ab87;p=linux-2.6-omap-h63xx.git 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 Updated to try to use cpufreq_table if it exists. Signed-off-by: Tony Lindgren --- diff --git a/arch/arm/mach-omap2/clock24xx.c b/arch/arm/mach-omap2/clock24xx.c index 58856d30ef0..975d35e38af 100644 --- a/arch/arm/mach-omap2/clock24xx.c +++ b/arch/arm/mach-omap2/clock24xx.c @@ -26,6 +26,7 @@ #include #include +#include #include #include @@ -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) diff --git a/arch/arm/plat-omap/clock.c b/arch/arm/plat-omap/clock.c index 70f2311e5c6..005bd1e3cb6 100644 --- a/arch/arm/plat-omap/clock.c +++ b/arch/arm/plat-omap/clock.c @@ -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 diff --git a/arch/arm/plat-omap/cpu-omap.c b/arch/arm/plat-omap/cpu-omap.c index d719c15daa5..fc6cd5e2b08 100644 --- a/arch/arm/plat-omap/cpu-omap.c +++ b/arch/arm/plat-omap/cpu-omap.c @@ -24,9 +24,12 @@ #include #include #include +#include #define VERY_HI_RATE 900000000 +static struct cpufreq_frequency_table *freq_table; + #ifdef CONFIG_ARCH_OMAP1 #define MPU_CLK "mpu" #else @@ -39,6 +42,9 @@ static struct clk *mpu_clk; int omap_verify_speed(struct cpufreq_policy *policy) { + if (freq_table) + return cpufreq_frequency_table_verify(policy, freq_table); + if (policy->cpu) return -EINVAL; @@ -70,12 +76,26 @@ static int omap_target(struct cpufreq_policy *policy, struct cpufreq_freqs freqs; int ret = 0; + /* Ensure desired rate is within allowed range. Some govenors + * (ondemand) will just pass target_freq=0 to get the minimum. */ + if (target_freq < policy->cpuinfo.min_freq) + target_freq = policy->cpuinfo.min_freq; + if (target_freq > policy->cpuinfo.max_freq) + target_freq = policy->cpuinfo.max_freq; + freqs.old = omap_getspeed(0); freqs.new = clk_round_rate(mpu_clk, target_freq * 1000) / 1000; freqs.cpu = 0; + if (freqs.old == freqs.new) + return ret; + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); - ret = clk_set_rate(mpu_clk, target_freq * 1000); +#ifdef CONFIG_CPU_FREQ_DEBUG + printk(KERN_DEBUG "cpufreq-omap: transition: %u --> %u\n", + freqs.old, freqs.new); +#endif + ret = clk_set_rate(mpu_clk, freqs.new * 1000); cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); return ret; @@ -83,16 +103,31 @@ static int omap_target(struct cpufreq_policy *policy, static int __init omap_cpu_init(struct cpufreq_policy *policy) { + int result = 0; + mpu_clk = clk_get(NULL, MPU_CLK); if (IS_ERR(mpu_clk)) return PTR_ERR(mpu_clk); if (policy->cpu != 0) return -EINVAL; + policy->cur = policy->min = policy->max = omap_getspeed(0); - policy->cpuinfo.min_freq = clk_round_rate(mpu_clk, 0) / 1000; - policy->cpuinfo.max_freq = clk_round_rate(mpu_clk, VERY_HI_RATE) / 1000; - policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; + + clk_init_cpufreq_table(&freq_table); + if (freq_table) { + result = cpufreq_frequency_table_cpuinfo(policy, freq_table); + if (!result) + cpufreq_frequency_table_get_attr(freq_table, + policy->cpu); + } else { + policy->cpuinfo.min_freq = clk_round_rate(mpu_clk, 0) / 1000; + policy->cpuinfo.max_freq = clk_round_rate(mpu_clk, + VERY_HI_RATE) / 1000; + } + + /* FIXME: what's the actual transition time? */ + policy->cpuinfo.transition_latency = 10 * 1000 * 1000; return 0; } @@ -103,6 +138,11 @@ static int omap_cpu_exit(struct cpufreq_policy *policy) return 0; } +static struct freq_attr *omap_cpufreq_attr[] = { + &cpufreq_freq_attr_scaling_available_freqs, + NULL, +}; + static struct cpufreq_driver omap_driver = { .flags = CPUFREQ_STICKY, .verify = omap_verify_speed, @@ -111,6 +151,7 @@ static struct cpufreq_driver omap_driver = { .init = omap_cpu_init, .exit = omap_cpu_exit, .name = "omap", + .attr = omap_cpufreq_attr, }; static int __init omap_cpufreq_init(void) @@ -119,3 +160,11 @@ static int __init omap_cpufreq_init(void) } arch_initcall(omap_cpufreq_init); + +/* + * if ever we want to remove this, upon cleanup call: + * + * cpufreq_unregister_driver() + * cpufreq_frequency_table_put_attr() + */ + diff --git a/include/asm-arm/arch-omap/clock.h b/include/asm-arm/arch-omap/clock.h index cb7a3016fd5..971d167b5eb 100644 --- a/include/asm-arm/arch-omap/clock.h +++ b/include/asm-arm/arch-omap/clock.h @@ -10,6 +10,8 @@ * published by the Free Software Foundation. */ +#include + #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 */