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https://github.com/torvalds/linux
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ceb7682ee3
Many common initializations of struct policy are moved to core now and hence this driver doesn't need to do it. This patch removes such code. Most recent of those changes is to call ->get() in the core after calling ->init(). Cc: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
150 lines
3.7 KiB
C
150 lines
3.7 KiB
C
/*
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* Copyright (C) STMicroelectronics 2009
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* Copyright (C) ST-Ericsson SA 2010-2012
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*
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* License Terms: GNU General Public License v2
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* Author: Sundar Iyer <sundar.iyer@stericsson.com>
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* Author: Martin Persson <martin.persson@stericsson.com>
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* Author: Jonas Aaberg <jonas.aberg@stericsson.com>
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/cpufreq.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/platform_device.h>
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#include <linux/clk.h>
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static struct cpufreq_frequency_table *freq_table;
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static struct clk *armss_clk;
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static int dbx500_cpufreq_target(struct cpufreq_policy *policy,
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unsigned int target_freq,
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unsigned int relation)
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{
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struct cpufreq_freqs freqs;
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unsigned int idx;
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int ret;
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/* Lookup the next frequency */
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if (cpufreq_frequency_table_target(policy, freq_table, target_freq,
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relation, &idx))
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return -EINVAL;
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freqs.old = policy->cur;
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freqs.new = freq_table[idx].frequency;
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if (freqs.old == freqs.new)
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return 0;
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/* pre-change notification */
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cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
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/* update armss clk frequency */
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ret = clk_set_rate(armss_clk, freqs.new * 1000);
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if (ret) {
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pr_err("dbx500-cpufreq: Failed to set armss_clk to %d Hz: error %d\n",
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freqs.new * 1000, ret);
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freqs.new = freqs.old;
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}
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/* post change notification */
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cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
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return ret;
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}
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static unsigned int dbx500_cpufreq_getspeed(unsigned int cpu)
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{
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int i = 0;
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unsigned long freq = clk_get_rate(armss_clk) / 1000;
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/* The value is rounded to closest frequency in the defined table. */
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while (freq_table[i + 1].frequency != CPUFREQ_TABLE_END) {
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if (freq < freq_table[i].frequency +
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(freq_table[i + 1].frequency - freq_table[i].frequency) / 2)
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return freq_table[i].frequency;
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i++;
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}
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return freq_table[i].frequency;
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}
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static int dbx500_cpufreq_init(struct cpufreq_policy *policy)
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{
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int res;
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/* get policy fields based on the table */
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res = cpufreq_table_validate_and_show(policy, freq_table);
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if (res) {
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pr_err("dbx500-cpufreq: Failed to read policy table\n");
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return res;
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}
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/*
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* FIXME : Need to take time measurement across the target()
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* function with no/some/all drivers in the notification
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* list.
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*/
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policy->cpuinfo.transition_latency = 20 * 1000; /* in ns */
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/* policy sharing between dual CPUs */
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cpumask_setall(policy->cpus);
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return 0;
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}
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static struct cpufreq_driver dbx500_cpufreq_driver = {
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.flags = CPUFREQ_STICKY | CPUFREQ_CONST_LOOPS,
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.verify = cpufreq_generic_frequency_table_verify,
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.target = dbx500_cpufreq_target,
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.get = dbx500_cpufreq_getspeed,
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.init = dbx500_cpufreq_init,
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.name = "DBX500",
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.attr = cpufreq_generic_attr,
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};
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static int dbx500_cpufreq_probe(struct platform_device *pdev)
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{
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int i = 0;
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freq_table = dev_get_platdata(&pdev->dev);
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if (!freq_table) {
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pr_err("dbx500-cpufreq: Failed to fetch cpufreq table\n");
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return -ENODEV;
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}
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armss_clk = clk_get(&pdev->dev, "armss");
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if (IS_ERR(armss_clk)) {
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pr_err("dbx500-cpufreq: Failed to get armss clk\n");
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return PTR_ERR(armss_clk);
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}
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pr_info("dbx500-cpufreq: Available frequencies:\n");
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while (freq_table[i].frequency != CPUFREQ_TABLE_END) {
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pr_info(" %d Mhz\n", freq_table[i].frequency/1000);
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i++;
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}
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return cpufreq_register_driver(&dbx500_cpufreq_driver);
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}
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static struct platform_driver dbx500_cpufreq_plat_driver = {
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.driver = {
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.name = "cpufreq-ux500",
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.owner = THIS_MODULE,
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},
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.probe = dbx500_cpufreq_probe,
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};
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static int __init dbx500_cpufreq_register(void)
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{
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return platform_driver_register(&dbx500_cpufreq_plat_driver);
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}
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device_initcall(dbx500_cpufreq_register);
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MODULE_LICENSE("GPL v2");
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MODULE_DESCRIPTION("cpufreq driver for DBX500");
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