+++ /dev/null
-/*
- * Copyright (C) 2010 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
- */
-
-/*
- * A driver for the Freescale Semiconductor i.MXC CPUfreq module.
- * The CPUFREQ driver is for controlling CPU frequency. It allows you to change
- * the CPU clock speed on the fly.
- */
-
-#include <linux/module.h>
-#include <linux/cpufreq.h>
-#include <linux/clk.h>
-#include <linux/err.h>
-#include <linux/slab.h>
-
-#include "hardware.h"
-
-#define CLK32_FREQ 32768
-#define NANOSECOND (1000 * 1000 * 1000)
-
-struct cpu_op *(*get_cpu_op)(int *op);
-
-static int cpu_freq_khz_min;
-static int cpu_freq_khz_max;
-
-static struct clk *cpu_clk;
-static struct cpufreq_frequency_table *imx_freq_table;
-
-static int cpu_op_nr;
-static struct cpu_op *cpu_op_tbl;
-
-static int set_cpu_freq(int freq)
-{
- int ret = 0;
- int org_cpu_rate;
-
- org_cpu_rate = clk_get_rate(cpu_clk);
- if (org_cpu_rate == freq)
- return ret;
-
- ret = clk_set_rate(cpu_clk, freq);
- if (ret != 0) {
- printk(KERN_DEBUG "cannot set CPU clock rate\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 mxc_set_target(struct cpufreq_policy *policy,
- unsigned int target_freq, unsigned int relation)
-{
- struct cpufreq_freqs freqs;
- int freq_Hz;
- int ret = 0;
- unsigned int index;
-
- cpufreq_frequency_table_target(policy, imx_freq_table,
- target_freq, relation, &index);
- freq_Hz = imx_freq_table[index].frequency * 1000;
-
- freqs.old = clk_get_rate(cpu_clk) / 1000;
- freqs.new = freq_Hz / 1000;
- freqs.cpu = 0;
- freqs.flags = 0;
- cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
-
- ret = set_cpu_freq(freq_Hz);
-
- cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
-
- return ret;
-}
-
-static int mxc_cpufreq_init(struct cpufreq_policy *policy)
-{
- int ret;
- int i;
-
- printk(KERN_INFO "i.MXC CPU frequency driver\n");
-
- if (policy->cpu != 0)
- return -EINVAL;
-
- if (!get_cpu_op)
- 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);
- }
-
- cpu_op_tbl = get_cpu_op(&cpu_op_nr);
-
- cpu_freq_khz_min = cpu_op_tbl[0].cpu_rate / 1000;
- cpu_freq_khz_max = cpu_op_tbl[0].cpu_rate / 1000;
-
- imx_freq_table = kmalloc(
- sizeof(struct cpufreq_frequency_table) * (cpu_op_nr + 1),
- GFP_KERNEL);
- if (!imx_freq_table) {
- ret = -ENOMEM;
- goto err1;
- }
-
- for (i = 0; i < cpu_op_nr; i++) {
- imx_freq_table[i].index = i;
- imx_freq_table[i].frequency = cpu_op_tbl[i].cpu_rate / 1000;
-
- if ((cpu_op_tbl[i].cpu_rate / 1000) < cpu_freq_khz_min)
- cpu_freq_khz_min = cpu_op_tbl[i].cpu_rate / 1000;
-
- if ((cpu_op_tbl[i].cpu_rate / 1000) > cpu_freq_khz_max)
- cpu_freq_khz_max = cpu_op_tbl[i].cpu_rate / 1000;
- }
-
- imx_freq_table[i].index = i;
- imx_freq_table[i].frequency = CPUFREQ_TABLE_END;
-
- policy->cur = clk_get_rate(cpu_clk) / 1000;
- policy->min = policy->cpuinfo.min_freq = cpu_freq_khz_min;
- policy->max = policy->cpuinfo.max_freq = cpu_freq_khz_max;
-
- /* Manual states, that PLL stabilizes in two CLK32 periods */
- policy->cpuinfo.transition_latency = 2 * NANOSECOND / CLK32_FREQ;
-
- ret = cpufreq_frequency_table_cpuinfo(policy, imx_freq_table);
-
- if (ret < 0) {
- printk(KERN_ERR "%s: failed to register i.MXC CPUfreq with error code %d\n",
- __func__, ret);
- goto err;
- }
-
- cpufreq_frequency_table_get_attr(imx_freq_table, policy->cpu);
- return 0;
-err:
- kfree(imx_freq_table);
-err1:
- clk_put(cpu_clk);
- return ret;
-}
-
-static int mxc_cpufreq_exit(struct cpufreq_policy *policy)
-{
- cpufreq_frequency_table_put_attr(policy->cpu);
-
- set_cpu_freq(cpu_freq_khz_max * 1000);
- clk_put(cpu_clk);
- kfree(imx_freq_table);
- 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_init,
- .exit = mxc_cpufreq_exit,
- .name = "imx",
-};
-
-static int mxc_cpufreq_driver_init(void)
-{
- return cpufreq_register_driver(&mxc_driver);
-}
-
-static void mxc_cpufreq_driver_exit(void)
-{
- cpufreq_unregister_driver(&mxc_driver);
-}
-
-module_init(mxc_cpufreq_driver_init);
-module_exit(mxc_cpufreq_driver_exit);
-
-MODULE_AUTHOR("Freescale Semiconductor Inc. Yong Shen <yong.shen@linaro.org>");
-MODULE_DESCRIPTION("CPUfreq driver for i.MX");
-MODULE_LICENSE("GPL");
projects / openwrt / staging / blogic.git / commitdiff