diff options
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/Makefile | 1 | ||||
| -rw-r--r-- | drivers/cpufreq/omap-cpufreq.c | 274 |
2 files changed, 275 insertions, 0 deletions
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index a48bc02cd76..ce75fcbcca4 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -43,6 +43,7 @@ obj-$(CONFIG_UX500_SOC_DB8500) += db8500-cpufreq.o obj-$(CONFIG_ARM_S3C64XX_CPUFREQ) += s3c64xx-cpufreq.o obj-$(CONFIG_ARM_S5PV210_CPUFREQ) += s5pv210-cpufreq.o obj-$(CONFIG_ARM_EXYNOS4210_CPUFREQ) += exynos4210-cpufreq.o +obj-$(CONFIG_ARCH_OMAP2PLUS) += omap-cpufreq.o ################################################################################## # PowerPC platform drivers diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c new file mode 100644 index 00000000000..5d04c57aae3 --- /dev/null +++ b/drivers/cpufreq/omap-cpufreq.c @@ -0,0 +1,274 @@ +/* + * CPU frequency scaling for OMAP using OPP information + * + * Copyright (C) 2005 Nokia Corporation + * Written by Tony Lindgren <tony@atomide.com> + * + * Based on cpu-sa1110.c, Copyright (C) 2001 Russell King + * + * Copyright (C) 2007-2011 Texas Instruments, Inc. + * - OMAP3/4 support by Rajendra Nayak, Santosh Shilimkar + * + * 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/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 <linux/opp.h> +#include <linux/cpu.h> +#include <linux/module.h> + +#include <asm/system.h> +#include <asm/smp_plat.h> +#include <asm/cpu.h> + +#include <plat/clock.h> +#include <plat/omap-pm.h> +#include <plat/common.h> +#include <plat/omap_device.h> + +#include <mach/hardware.h> + +#ifdef CONFIG_SMP +struct lpj_info { + unsigned long ref; + unsigned int freq; +}; + +static DEFINE_PER_CPU(struct lpj_info, lpj_ref); +static struct lpj_info global_lpj_ref; +#endif + +static struct cpufreq_frequency_table *freq_table; +static atomic_t freq_table_users = ATOMIC_INIT(0); +static struct clk *mpu_clk; +static char *mpu_clk_name; +static struct device *mpu_dev; + +static int omap_verify_speed(struct cpufreq_policy *policy) +{ + if (!freq_table) + return -EINVAL; + return cpufreq_frequency_table_verify(policy, freq_table); +} + +static unsigned int omap_getspeed(unsigned int cpu) +{ + unsigned long rate; + + if (cpu >= NR_CPUS) + return 0; + + rate = clk_get_rate(mpu_clk) / 1000; + return rate; +} + +static int omap_target(struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation) +{ + unsigned int i; + int ret = 0; + struct cpufreq_freqs freqs; + + if (!freq_table) { + dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__, + policy->cpu); + return -EINVAL; + } + + ret = cpufreq_frequency_table_target(policy, freq_table, target_freq, + relation, &i); + if (ret) { + dev_dbg(mpu_dev, "%s: cpu%d: no freq match for %d(ret=%d)\n", + __func__, policy->cpu, target_freq, ret); + return ret; + } + freqs.new = freq_table[i].frequency; + if (!freqs.new) { + dev_err(mpu_dev, "%s: cpu%d: no match for freq %d\n", __func__, + policy->cpu, target_freq); + return -EINVAL; + } + + freqs.old = omap_getspeed(policy->cpu); + freqs.cpu = policy->cpu; + + if (freqs.old == freqs.new && policy->cur == freqs.new) + return ret; + + /* notifiers */ + for_each_cpu(i, policy->cpus) { + freqs.cpu = i; + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); + } + +#ifdef CONFIG_CPU_FREQ_DEBUG + pr_info("cpufreq-omap: transition: %u --> %u\n", freqs.old, freqs.new); +#endif + + ret = clk_set_rate(mpu_clk, freqs.new * 1000); + freqs.new = omap_getspeed(policy->cpu); + +#ifdef CONFIG_SMP + /* + * Note that loops_per_jiffy is not updated on SMP systems in + * cpufreq driver. So, update the per-CPU loops_per_jiffy value + * on frequency transition. We need to update all dependent CPUs. + */ + for_each_cpu(i, policy->cpus) { + struct lpj_info *lpj = &per_cpu(lpj_ref, i); + if (!lpj->freq) { + lpj->ref = per_cpu(cpu_data, i).loops_per_jiffy; + lpj->freq = freqs.old; + } + + per_cpu(cpu_data, i).loops_per_jiffy = + cpufreq_scale(lpj->ref, lpj->freq, freqs.new); + } + + /* And don't forget to adjust the global one */ + if (!global_lpj_ref.freq) { + global_lpj_ref.ref = loops_per_jiffy; + global_lpj_ref.freq = freqs.old; + } + loops_per_jiffy = cpufreq_scale(global_lpj_ref.ref, global_lpj_ref.freq, + freqs.new); +#endif + + /* notifiers */ + for_each_cpu(i, policy->cpus) { + freqs.cpu = i; + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); + } + + return ret; +} + +static inline void freq_table_free(void) +{ + if (atomic_dec_and_test(&freq_table_users)) + opp_free_cpufreq_table(mpu_dev, &freq_table); +} + +static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy) +{ + int result = 0; + + mpu_clk = clk_get(NULL, mpu_clk_name); + if (IS_ERR(mpu_clk)) + return PTR_ERR(mpu_clk); + + if (policy->cpu >= NR_CPUS) { + result = -EINVAL; + goto fail_ck; + } + + policy->cur = policy->min = policy->max = omap_getspeed(policy->cpu); + + if (atomic_inc_return(&freq_table_users) == 1) + result = opp_init_cpufreq_table(mpu_dev, &freq_table); + + if (result) { + dev_err(mpu_dev, "%s: cpu%d: failed creating freq table[%d]\n", + __func__, policy->cpu, result); + goto fail_ck; + } + + result = cpufreq_frequency_table_cpuinfo(policy, freq_table); + if (result) + goto fail_table; + + cpufreq_frequency_table_get_attr(freq_table, policy->cpu); + + policy->min = policy->cpuinfo.min_freq; + policy->max = policy->cpuinfo.max_freq; + policy->cur = omap_getspeed(policy->cpu); + + /* + * On OMAP SMP configuartion, both processors share the voltage + * and clock. So both CPUs needs to be scaled together and hence + * needs software co-ordination. Use cpufreq affected_cpus + * interface to handle this scenario. Additional is_smp() check + * is to keep SMP_ON_UP build working. + */ + if (is_smp()) { + policy->shared_type = CPUFREQ_SHARED_TYPE_ANY; + cpumask_setall(policy->cpus); + } + + /* FIXME: what's the actual transition time? */ + policy->cpuinfo.transition_latency = 300 * 1000; + + return 0; + +fail_table: + freq_table_free(); +fail_ck: + clk_put(mpu_clk); + return result; +} + +static int omap_cpu_exit(struct cpufreq_policy *policy) +{ + freq_table_free(); + clk_put(mpu_clk); + 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, + .target = omap_target, + .get = omap_getspeed, + .init = omap_cpu_init, + .exit = omap_cpu_exit, + .name = "omap", + .attr = omap_cpufreq_attr, +}; + +static int __init omap_cpufreq_init(void) +{ + if (cpu_is_omap24xx()) + mpu_clk_name = "virt_prcm_set"; + else if (cpu_is_omap34xx()) + mpu_clk_name = "dpll1_ck"; + else if (cpu_is_omap44xx()) + mpu_clk_name = "dpll_mpu_ck"; + + if (!mpu_clk_name) { + pr_err("%s: unsupported Silicon?\n", __func__); + return -EINVAL; + } + + mpu_dev = omap_device_get_by_hwmod_name("mpu"); + if (!mpu_dev) { + pr_warning("%s: unable to get the mpu device\n", __func__); + return -EINVAL; + } + + return cpufreq_register_driver(&omap_driver); +} + +static void __exit omap_cpufreq_exit(void) +{ + cpufreq_unregister_driver(&omap_driver); +} + +MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs"); +MODULE_LICENSE("GPL"); +module_init(omap_cpufreq_init); +module_exit(omap_cpufreq_exit); |