diff options
| -rw-r--r-- | arch/avr32/Kconfig | 21 | ||||
| -rw-r--r-- | arch/avr32/mach-at32ap/Makefile | 1 | ||||
| -rw-r--r-- | arch/avr32/mach-at32ap/at32ap7000.c | 43 | ||||
| -rw-r--r-- | arch/avr32/mach-at32ap/cpufreq.c | 112 |
4 files changed, 175 insertions, 2 deletions
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig index 3ec76586877..8f37a14e637 100644 --- a/arch/avr32/Kconfig +++ b/arch/avr32/Kconfig @@ -185,6 +185,27 @@ config CMDLINE endmenu +menu "Power managment options" + +menu "CPU Frequency scaling" + +source "drivers/cpufreq/Kconfig" + +config CPU_FREQ_AT32AP + bool "CPU frequency driver for AT32AP" + depends on CPU_FREQ && PLATFORM_AT32AP + default n + help + This enables the CPU frequency driver for AT32AP processors. + + For details, take a look in <file:Documentation/cpu-freq>. + + If in doubt, say N. + +endmenu + +endmenu + menu "Bus options" config PCI diff --git a/arch/avr32/mach-at32ap/Makefile b/arch/avr32/mach-at32ap/Makefile index f1d395724ac..a8b445046e3 100644 --- a/arch/avr32/mach-at32ap/Makefile +++ b/arch/avr32/mach-at32ap/Makefile @@ -1,3 +1,4 @@ obj-y += at32ap.o clock.o intc.o extint.o pio.o hsmc.o obj-$(CONFIG_CPU_AT32AP7000) += at32ap7000.o obj-$(CONFIG_CPU_AT32AP7000) += time-tc.o +obj-$(CONFIG_CPU_FREQ_AT32AP) += cpufreq.o diff --git a/arch/avr32/mach-at32ap/at32ap7000.c b/arch/avr32/mach-at32ap/at32ap7000.c index 5faa97e5ab1..c74f3715f3f 100644 --- a/arch/avr32/mach-at32ap/at32ap7000.c +++ b/arch/avr32/mach-at32ap/at32ap7000.c @@ -219,6 +219,41 @@ static unsigned long cpu_clk_get_rate(struct clk *clk) return bus_clk_get_rate(clk, shift); } +static long cpu_clk_set_rate(struct clk *clk, unsigned long rate, int apply) +{ + u32 control; + unsigned long parent_rate, child_div, actual_rate, div; + + parent_rate = clk->parent->get_rate(clk->parent); + control = pm_readl(CKSEL); + + if (control & PM_BIT(HSBDIV)) + child_div = 1 << (PM_BFEXT(HSBSEL, control) + 1); + else + child_div = 1; + + if (rate > 3 * (parent_rate / 4) || child_div == 1) { + actual_rate = parent_rate; + control &= ~PM_BIT(CPUDIV); + } else { + unsigned int cpusel; + div = (parent_rate + rate / 2) / rate; + if (div > child_div) + div = child_div; + cpusel = (div > 1) ? (fls(div) - 2) : 0; + control = PM_BIT(CPUDIV) | PM_BFINS(CPUSEL, cpusel, control); + actual_rate = parent_rate / (1 << (cpusel + 1)); + } + + pr_debug("clk %s: new rate %lu (actual rate %lu)\n", + clk->name, rate, actual_rate); + + if (apply) + pm_writel(CKSEL, control); + + return actual_rate; +} + static void hsb_clk_mode(struct clk *clk, int enabled) { unsigned long flags; @@ -300,6 +335,7 @@ static unsigned long pbb_clk_get_rate(struct clk *clk) static struct clk cpu_clk = { .name = "cpu", .get_rate = cpu_clk_get_rate, + .set_rate = cpu_clk_set_rate, .users = 1, }; static struct clk hsb_clk = { @@ -1152,10 +1188,13 @@ void __init at32_clock_init(void) u32 cpu_mask = 0, hsb_mask = 0, pba_mask = 0, pbb_mask = 0; int i; - if (pm_readl(MCCTRL) & PM_BIT(PLLSEL)) + if (pm_readl(MCCTRL) & PM_BIT(PLLSEL)) { main_clock = &pll0; - else + cpu_clk.parent = &pll0; + } else { main_clock = &osc0; + cpu_clk.parent = &osc0; + } if (pm_readl(PLL0) & PM_BIT(PLLOSC)) pll0.parent = &osc1; diff --git a/arch/avr32/mach-at32ap/cpufreq.c b/arch/avr32/mach-at32ap/cpufreq.c new file mode 100644 index 00000000000..235524b7919 --- /dev/null +++ b/arch/avr32/mach-at32ap/cpufreq.c @@ -0,0 +1,112 @@ +/* + * Copyright (C) 2004-2007 Atmel Corporation + * + * Based on MIPS implementation arch/mips/kernel/time.c + * Copyright 2001 MontaVista Software Inc. + * + * 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. + */ + +/*#define DEBUG*/ + +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/init.h> +#include <linux/cpufreq.h> +#include <linux/io.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <asm/system.h> + +static struct clk *cpuclk; + +static int at32_verify_speed(struct cpufreq_policy *policy) +{ + if (policy->cpu != 0) + return -EINVAL; + + cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, + policy->cpuinfo.max_freq); + return 0; +} + +static unsigned int at32_get_speed(unsigned int cpu) +{ + /* No SMP support */ + if (cpu) + return 0; + return (unsigned int)((clk_get_rate(cpuclk) + 500) / 1000); +} + +static int at32_set_target(struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation) +{ + struct cpufreq_freqs freqs; + long freq; + + /* Convert target_freq from kHz to Hz */ + freq = clk_round_rate(cpuclk, target_freq * 1000); + + /* Check if policy->min <= new_freq <= policy->max */ + if(freq < (policy->min * 1000) || freq > (policy->max * 1000)) + return -EINVAL; + + pr_debug("cpufreq: requested frequency %u Hz\n", target_freq * 1000); + + freqs.old = at32_get_speed(0); + freqs.new = (freq + 500) / 1000; + freqs.cpu = 0; + freqs.flags = 0; + + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); + clk_set_rate(cpuclk, freq); + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); + + pr_debug("cpufreq: set frequency %lu Hz\n", freq); + + return 0; +} + +static int __init at32_cpufreq_driver_init(struct cpufreq_policy *policy) +{ + if (policy->cpu != 0) + return -EINVAL; + + cpuclk = clk_get(NULL, "cpu"); + if (IS_ERR(cpuclk)) { + pr_debug("cpufreq: could not get CPU clk\n"); + return PTR_ERR(cpuclk); + } + + policy->cpuinfo.min_freq = (clk_round_rate(cpuclk, 1) + 500) / 1000; + policy->cpuinfo.max_freq = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000; + policy->cpuinfo.transition_latency = 0; + policy->cur = at32_get_speed(0); + policy->min = policy->cpuinfo.min_freq; + policy->max = policy->cpuinfo.max_freq; + policy->governor = CPUFREQ_DEFAULT_GOVERNOR; + + printk("cpufreq: AT32AP CPU frequency driver\n"); + + return 0; +} + +static struct cpufreq_driver at32_driver = { + .name = "at32ap", + .owner = THIS_MODULE, + .init = at32_cpufreq_driver_init, + .verify = at32_verify_speed, + .target = at32_set_target, + .get = at32_get_speed, + .flags = CPUFREQ_STICKY, +}; + +static int __init at32_cpufreq_init(void) +{ + return cpufreq_register_driver(&at32_driver); +} + +arch_initcall(at32_cpufreq_init); |