diff options
Diffstat (limited to 'arch/arm/plat-mxc/cpufreq.c')
| -rw-r--r-- | arch/arm/plat-mxc/cpufreq.c | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/arch/arm/plat-mxc/cpufreq.c b/arch/arm/plat-mxc/cpufreq.c new file mode 100644 index 000000000000..312cb6574676 --- /dev/null +++ b/arch/arm/plat-mxc/cpufreq.c @@ -0,0 +1,330 @@ +/* + * Copyright 2009 Freescale Semiconductor, Inc. All Rights Reserved. + */ + +/* + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ + +/*! + * @file cpufreq.c + * + * @brief A driver for the Freescale Semiconductor i.MXC CPUfreq module. + * + * The CPUFREQ driver is for controling CPU frequency. It allows you to change + * the CPU clock speed on the fly. + * + * @ingroup PM + */ + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/cpufreq.h> +#include <linux/init.h> +#include <linux/proc_fs.h> +#include <linux/regulator/consumer.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <mach/hardware.h> +#include <asm/setup.h> +#include <mach/clock.h> +#include <asm/cacheflush.h> +#include <linux/hrtimer.h> + +int cpu_freq_khz_min; +int cpu_freq_khz_max; +int arm_lpm_clk; +int arm_normal_clk; +int cpufreq_suspended; +int cpufreq_trig_needed; + +static struct clk *cpu_clk; +static struct regulator *gp_regulator; +static struct cpu_wp *cpu_wp_tbl; +static struct cpufreq_frequency_table imx_freq_table[4]; +extern int low_bus_freq_mode; +extern int high_bus_freq_mode; +extern int dvfs_core_is_active; +extern int cpu_wp_nr; +extern char *gp_reg_id; + +extern int set_low_bus_freq(void); +extern int set_high_bus_freq(int high_bus_speed); +extern int low_freq_bus_used(void); + +#ifdef CONFIG_ARCH_MX51 +extern struct cpu_wp *(*get_cpu_wp)(int *wp); +#endif + +int set_cpu_freq(int freq) +{ + int ret = 0; + int org_cpu_rate; + int gp_volt = 0; + int i; + + org_cpu_rate = clk_get_rate(cpu_clk); + if (org_cpu_rate == freq) + return ret; + + for (i = 0; i < cpu_wp_nr; i++) { + if (freq == cpu_wp_tbl[i].cpu_rate) + gp_volt = cpu_wp_tbl[i].cpu_voltage; + } + + if (gp_volt == 0) + return ret; + + /*Set the voltage for the GP domain. */ + if (freq > org_cpu_rate) { + ret = regulator_set_voltage(gp_regulator, gp_volt, gp_volt); + if (ret < 0) { + printk(KERN_DEBUG "COULD NOT SET GP VOLTAGE!!!!\n"); + return ret; + } + } + + ret = clk_set_rate(cpu_clk, freq); + if (ret != 0) { + printk(KERN_DEBUG "cannot set CPU clock rate\n"); + return ret; + } + + if (freq < org_cpu_rate) { + ret = regulator_set_voltage(gp_regulator, gp_volt, gp_volt); + if (ret < 0) { + printk(KERN_DEBUG "COULD NOT SET GP VOLTAGE!!!!\n"); + return ret; + } + } + + return ret; +} + +static int mxc_verify_speed(struct cpufreq_policy *policy) +{ + if (policy->cpu != 0) + return -EINVAL; + + return cpufreq_frequency_table_verify(policy, imx_freq_table); +} + +static unsigned int mxc_get_speed(unsigned int cpu) +{ + if (cpu) + return 0; + + return clk_get_rate(cpu_clk) / 1000; +} + +static int calc_frequency_khz(int target, unsigned int relation) +{ + int i; + + if ((target * 1000) == clk_get_rate(cpu_clk)) + return target; + + if (relation == CPUFREQ_RELATION_H) { + for (i = cpu_wp_nr - 1; i >= 0; i--) { + if (imx_freq_table[i].frequency <= target) + return imx_freq_table[i].frequency; + } + } else if (relation == CPUFREQ_RELATION_L) { + for (i = 0; i < cpu_wp_nr; i++) { + if (imx_freq_table[i].frequency >= target) + return imx_freq_table[i].frequency; + } + } + printk(KERN_ERR "Error: No valid cpufreq relation\n"); + return cpu_freq_khz_max; +} + +static int mxc_set_target(struct cpufreq_policy *policy, + unsigned int target_freq, unsigned int relation) +{ + struct cpufreq_freqs freqs; + int freq_Hz; + int low_freq_bus_ready = 0; + int ret = 0; + + if (dvfs_core_is_active || cpufreq_suspended) { + target_freq = clk_get_rate(cpu_clk) / 1000; + freq_Hz = calc_frequency_khz(target_freq, relation) * 1000; + if (freq_Hz == arm_lpm_clk) + freqs.old = cpu_wp_tbl[cpu_wp_nr - 2].cpu_rate / 1000; + else + freqs.old = arm_lpm_clk / 1000; + + freqs.new = freq_Hz / 1000; + freqs.cpu = 0; + freqs.flags = 0; + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); + return ret; + } + /* + * Some governors do not respects CPU and policy lower limits + * which leads to bad things (division by zero etc), ensure + * that such things do not happen. + */ + if (target_freq < policy->cpuinfo.min_freq) + target_freq = policy->cpuinfo.min_freq; + + if (target_freq < policy->min) + target_freq = policy->min; + + freq_Hz = calc_frequency_khz(target_freq, relation) * 1000; + + freqs.old = clk_get_rate(cpu_clk) / 1000; + freqs.new = freq_Hz / 1000; + freqs.cpu = 0; + freqs.flags = 0; + low_freq_bus_ready = low_freq_bus_used(); + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); + if (!dvfs_core_is_active) { + if ((freq_Hz == arm_lpm_clk) && (!low_bus_freq_mode) + && (low_freq_bus_ready)) { + if (freqs.old != freqs.new) + ret = set_cpu_freq(freq_Hz); + set_low_bus_freq(); + + } else { + set_high_bus_freq(0); + ret = set_cpu_freq(freq_Hz); + } + } + + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); + + return ret; +} + +static int __init mxc_cpufreq_driver_init(struct cpufreq_policy *policy) +{ + int ret; + int i; + + printk(KERN_INFO "i.MXC CPU frequency driver\n"); + + if (policy->cpu != 0) + return -EINVAL; + + cpu_clk = clk_get(NULL, "cpu_clk"); + if (IS_ERR(cpu_clk)) { + printk(KERN_ERR "%s: failed to get cpu clock\n", __func__); + return PTR_ERR(cpu_clk); + } + + gp_regulator = regulator_get(NULL, gp_reg_id); + if (IS_ERR(gp_regulator)) { + clk_put(cpu_clk); + printk(KERN_ERR "%s: failed to get gp regulator\n", __func__); + return PTR_ERR(gp_regulator); + } + + /* Set the current working point. */ + cpu_wp_tbl = get_cpu_wp(&cpu_wp_nr); + + cpu_freq_khz_min = cpu_wp_tbl[0].cpu_rate / 1000; + cpu_freq_khz_max = cpu_wp_tbl[0].cpu_rate / 1000; + + for (i = 0; i < cpu_wp_nr; i++) { + imx_freq_table[cpu_wp_nr - 1 - i].index = cpu_wp_nr - i; + imx_freq_table[cpu_wp_nr - 1 - i].frequency = + cpu_wp_tbl[i].cpu_rate / 1000; + + if ((cpu_wp_tbl[i].cpu_rate / 1000) < cpu_freq_khz_min) + cpu_freq_khz_min = cpu_wp_tbl[i].cpu_rate / 1000; + + if ((cpu_wp_tbl[i].cpu_rate / 1000) > cpu_freq_khz_max) + cpu_freq_khz_max = cpu_wp_tbl[i].cpu_rate / 1000; + } + + imx_freq_table[i].index = 0; + imx_freq_table[i].frequency = CPUFREQ_TABLE_END; + + policy->cur = clk_get_rate(cpu_clk) / 1000; + policy->governor = CPUFREQ_DEFAULT_GOVERNOR; + policy->min = policy->cpuinfo.min_freq = cpu_freq_khz_min; + policy->max = policy->cpuinfo.max_freq = cpu_freq_khz_max; + + arm_lpm_clk = cpu_freq_khz_min * 1000; + arm_normal_clk = cpu_freq_khz_max * 1000; + + /* Manual states, that PLL stabilizes in two CLK32 periods */ + policy->cpuinfo.transition_latency = 10; + + ret = cpufreq_frequency_table_cpuinfo(policy, imx_freq_table); + + if (ret < 0) { + clk_put(cpu_clk); + regulator_put(gp_regulator); + printk(KERN_ERR "%s: failed to register i.MXC CPUfreq\n", + __func__); + return ret; + } + + cpufreq_frequency_table_get_attr(imx_freq_table, policy->cpu); + return 0; +} + +static int mxc_cpufreq_suspend(struct cpufreq_policy *policy, + pm_message_t state) +{ + return 0; +} + +static int mxc_cpufreq_resume(struct cpufreq_policy *policy) +{ + return 0; +} + +static int mxc_cpufreq_driver_exit(struct cpufreq_policy *policy) +{ + cpufreq_frequency_table_put_attr(policy->cpu); + + /* Reset CPU to 665MHz */ + if (!dvfs_core_is_active) + set_cpu_freq(arm_normal_clk); + if (!high_bus_freq_mode) + set_high_bus_freq(1); + + clk_put(cpu_clk); + regulator_put(gp_regulator); + return 0; +} + +static struct cpufreq_driver mxc_driver = { + .flags = CPUFREQ_STICKY, + .verify = mxc_verify_speed, + .target = mxc_set_target, + .get = mxc_get_speed, + .init = mxc_cpufreq_driver_init, + .exit = mxc_cpufreq_driver_exit, + .suspend = mxc_cpufreq_suspend, + .resume = mxc_cpufreq_resume, + .name = "imx", +}; + +static int __devinit mxc_cpufreq_init(void) +{ + return cpufreq_register_driver(&mxc_driver); +} + +static void mxc_cpufreq_exit(void) +{ + cpufreq_unregister_driver(&mxc_driver); +} + +module_init(mxc_cpufreq_init); +module_exit(mxc_cpufreq_exit); + +MODULE_AUTHOR("Freescale Semiconductor, Inc."); +MODULE_DESCRIPTION("CPUfreq driver for i.MX"); +MODULE_LICENSE("GPL"); |