diff options
Diffstat (limited to 'drivers/cpufreq/integrator-cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/integrator-cpufreq.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/cpufreq/integrator-cpufreq.c b/drivers/cpufreq/integrator-cpufreq.c new file mode 100644 index 0000000..f7c99df --- /dev/null +++ b/drivers/cpufreq/integrator-cpufreq.c @@ -0,0 +1,220 @@ +/* + * Copyright (C) 2001-2002 Deep Blue Solutions Ltd. + * + * 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. + * + * CPU support functions + */ +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/cpufreq.h> +#include <linux/sched.h> +#include <linux/smp.h> +#include <linux/init.h> +#include <linux/io.h> + +#include <mach/hardware.h> +#include <mach/platform.h> +#include <asm/mach-types.h> +#include <asm/hardware/icst.h> + +static struct cpufreq_driver integrator_driver; + +#define CM_ID __io_address(INTEGRATOR_HDR_ID) +#define CM_OSC __io_address(INTEGRATOR_HDR_OSC) +#define CM_STAT __io_address(INTEGRATOR_HDR_STAT) +#define CM_LOCK __io_address(INTEGRATOR_HDR_LOCK) + +static const struct icst_params lclk_params = { + .ref = 24000000, + .vco_max = ICST525_VCO_MAX_5V, + .vco_min = ICST525_VCO_MIN, + .vd_min = 8, + .vd_max = 132, + .rd_min = 24, + .rd_max = 24, + .s2div = icst525_s2div, + .idx2s = icst525_idx2s, +}; + +static const struct icst_params cclk_params = { + .ref = 24000000, + .vco_max = ICST525_VCO_MAX_5V, + .vco_min = ICST525_VCO_MIN, + .vd_min = 12, + .vd_max = 160, + .rd_min = 24, + .rd_max = 24, + .s2div = icst525_s2div, + .idx2s = icst525_idx2s, +}; + +/* + * Validate the speed policy. + */ +static int integrator_verify_policy(struct cpufreq_policy *policy) +{ + struct icst_vco vco; + + cpufreq_verify_within_limits(policy, + policy->cpuinfo.min_freq, + policy->cpuinfo.max_freq); + + vco = icst_hz_to_vco(&cclk_params, policy->max * 1000); + policy->max = icst_hz(&cclk_params, vco) / 1000; + + vco = icst_hz_to_vco(&cclk_params, policy->min * 1000); + policy->min = icst_hz(&cclk_params, vco) / 1000; + + cpufreq_verify_within_limits(policy, + policy->cpuinfo.min_freq, + policy->cpuinfo.max_freq); + + return 0; +} + + +static int integrator_set_target(struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation) +{ + cpumask_t cpus_allowed; + int cpu = policy->cpu; + struct icst_vco vco; + struct cpufreq_freqs freqs; + u_int cm_osc; + + /* + * Save this threads cpus_allowed mask. + */ + cpus_allowed = current->cpus_allowed; + + /* + * Bind to the specified CPU. When this call returns, + * we should be running on the right CPU. + */ + set_cpus_allowed(current, cpumask_of_cpu(cpu)); + BUG_ON(cpu != smp_processor_id()); + + /* get current setting */ + cm_osc = __raw_readl(CM_OSC); + + if (machine_is_integrator()) { + vco.s = (cm_osc >> 8) & 7; + } else if (machine_is_cintegrator()) { + vco.s = 1; + } + vco.v = cm_osc & 255; + vco.r = 22; + freqs.old = icst_hz(&cclk_params, vco) / 1000; + + /* icst_hz_to_vco rounds down -- so we need the next + * larger freq in case of CPUFREQ_RELATION_L. + */ + if (relation == CPUFREQ_RELATION_L) + target_freq += 999; + if (target_freq > policy->max) + target_freq = policy->max; + vco = icst_hz_to_vco(&cclk_params, target_freq * 1000); + freqs.new = icst_hz(&cclk_params, vco) / 1000; + + if (freqs.old == freqs.new) { + set_cpus_allowed(current, cpus_allowed); + return 0; + } + + cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); + + cm_osc = __raw_readl(CM_OSC); + + if (machine_is_integrator()) { + cm_osc &= 0xfffff800; + cm_osc |= vco.s << 8; + } else if (machine_is_cintegrator()) { + cm_osc &= 0xffffff00; + } + cm_osc |= vco.v; + + __raw_writel(0xa05f, CM_LOCK); + __raw_writel(cm_osc, CM_OSC); + __raw_writel(0, CM_LOCK); + + /* + * Restore the CPUs allowed mask. + */ + set_cpus_allowed(current, cpus_allowed); + + cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); + + return 0; +} + +static unsigned int integrator_get(unsigned int cpu) +{ + cpumask_t cpus_allowed; + unsigned int current_freq; + u_int cm_osc; + struct icst_vco vco; + + cpus_allowed = current->cpus_allowed; + + set_cpus_allowed(current, cpumask_of_cpu(cpu)); + BUG_ON(cpu != smp_processor_id()); + + /* detect memory etc. */ + cm_osc = __raw_readl(CM_OSC); + + if (machine_is_integrator()) { + vco.s = (cm_osc >> 8) & 7; + } else { + vco.s = 1; + } + vco.v = cm_osc & 255; + vco.r = 22; + + current_freq = icst_hz(&cclk_params, vco) / 1000; /* current freq */ + + set_cpus_allowed(current, cpus_allowed); + + return current_freq; +} + +static int integrator_cpufreq_init(struct cpufreq_policy *policy) +{ + + /* set default policy and cpuinfo */ + policy->cpuinfo.max_freq = 160000; + policy->cpuinfo.min_freq = 12000; + policy->cpuinfo.transition_latency = 1000000; /* 1 ms, assumed */ + policy->cur = policy->min = policy->max = integrator_get(policy->cpu); + + return 0; +} + +static struct cpufreq_driver integrator_driver = { + .verify = integrator_verify_policy, + .target = integrator_set_target, + .get = integrator_get, + .init = integrator_cpufreq_init, + .name = "integrator", +}; + +static int __init integrator_cpu_init(void) +{ + return cpufreq_register_driver(&integrator_driver); +} + +static void __exit integrator_cpu_exit(void) +{ + cpufreq_unregister_driver(&integrator_driver); +} + +MODULE_AUTHOR ("Russell M. King"); +MODULE_DESCRIPTION ("cpufreq driver for ARM Integrator CPUs"); +MODULE_LICENSE ("GPL"); + +module_init(integrator_cpu_init); +module_exit(integrator_cpu_exit); |