diff options
| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-04-28 04:10:46 +0400 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-04-28 04:10:46 +0400 |
| commit | 885f925eef411f549f17bc64dd054a3269cf66cd (patch) | |
| tree | 6bac783d573a51e497ad28c19b5a71defac85f39 /drivers/cpufreq/at32ap-cpufreq.c | |
| parent | e4f5a3adc454745fea35f1c312e14cbeba6e0ea4 (diff) | |
| parent | 45c009a9a447655aecbdb06c86126f05d0272171 (diff) | |
| download | linux-885f925eef411f549f17bc64dd054a3269cf66cd.tar.xz | |
Merge branch 'pm-cpufreq'
* pm-cpufreq: (57 commits)
cpufreq: MAINTAINERS: Add co-maintainer
cpufreq: pxa2xx: initialize variables
ARM: S5pv210: compiling issue, ARM_S5PV210_CPUFREQ needs CONFIG_CPU_FREQ_TABLE=y
cpufreq: cpu0: Put cpu parent node after using it
cpufreq: ARM big LITTLE: Adapt to latest cpufreq updates
cpufreq: ARM big LITTLE: put DT nodes after using them
cpufreq: Don't call __cpufreq_governor() for drivers without target()
cpufreq: exynos5440: Protect OPP search calls with RCU lock
cpufreq: dbx500: Round to closest available freq
cpufreq: Call __cpufreq_governor() with correct policy->cpus mask
cpufreq / intel_pstate: Optimize intel_pstate_set_policy
cpufreq: OMAP: instantiate omap-cpufreq as a platform_driver
arm: exynos: Enable OPP library support for exynos5440
cpufreq: exynos: Remove error return even if no soc is found
cpufreq: exynos: Add cpufreq driver for exynos5440
cpufreq: AMD "frequency sensitivity feedback" powersave bias for ondemand governor
cpufreq: ondemand: allow custom powersave_bias_target handler to be registered
cpufreq: convert cpufreq_driver to using RCU
cpufreq: powerpc/platforms/cell: move cpufreq driver to drivers/cpufreq
cpufreq: sparc: move cpufreq driver to drivers/cpufreq
...
Conflicts:
MAINTAINERS (with commit a8e39c3 from pm-cpuidle)
drivers/cpufreq/cpufreq_governor.h (with commit beb0ff3)
Diffstat (limited to 'drivers/cpufreq/at32ap-cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/at32ap-cpufreq.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/drivers/cpufreq/at32ap-cpufreq.c b/drivers/cpufreq/at32ap-cpufreq.c new file mode 100644 index 000000000000..654488723cb5 --- /dev/null +++ b/drivers/cpufreq/at32ap-cpufreq.c @@ -0,0 +1,123 @@ +/* + * 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 <linux/export.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 unsigned int ref_freq; +static unsigned long loops_per_jiffy_ref; + +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.flags = 0; + + if (!ref_freq) { + ref_freq = freqs.old; + loops_per_jiffy_ref = boot_cpu_data.loops_per_jiffy; + } + + cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); + if (freqs.old < freqs.new) + boot_cpu_data.loops_per_jiffy = cpufreq_scale( + loops_per_jiffy_ref, ref_freq, freqs.new); + clk_set_rate(cpuclk, freq); + if (freqs.new < freqs.old) + boot_cpu_data.loops_per_jiffy = cpufreq_scale( + loops_per_jiffy_ref, ref_freq, freqs.new); + cpufreq_notify_transition(policy, &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; + + 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); +} +late_initcall(at32_cpufreq_init); |