/* * Copyright (C) STMicroelectronics 2009 * Copyright (C) ST-Ericsson SA 2010-2012 * * License Terms: GNU General Public License v2 * Author: Sundar Iyer * Author: Martin Persson * Author: Jonas Aaberg */ #include #include #include #include #include #include #include static struct cpufreq_frequency_table *freq_table; static struct clk *armss_clk; static struct freq_attr *dbx500_cpufreq_attr[] = { &cpufreq_freq_attr_scaling_available_freqs, NULL, }; static int dbx500_cpufreq_verify_speed(struct cpufreq_policy *policy) { return cpufreq_frequency_table_verify(policy, freq_table); } static int dbx500_cpufreq_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation) { struct cpufreq_freqs freqs; unsigned int idx; int ret; /* scale the target frequency to one of the extremes supported */ if (target_freq < policy->cpuinfo.min_freq) target_freq = policy->cpuinfo.min_freq; if (target_freq > policy->cpuinfo.max_freq) target_freq = policy->cpuinfo.max_freq; /* Lookup the next frequency */ if (cpufreq_frequency_table_target(policy, freq_table, target_freq, relation, &idx)) return -EINVAL; freqs.old = policy->cur; freqs.new = freq_table[idx].frequency; if (freqs.old == freqs.new) return 0; /* pre-change notification */ cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); /* update armss clk frequency */ ret = clk_set_rate(armss_clk, freqs.new * 1000); if (ret) { pr_err("dbx500-cpufreq: Failed to set armss_clk to %d Hz: error %d\n", freqs.new * 1000, ret); return ret; } /* post change notification */ cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); return 0; } static unsigned int dbx500_cpufreq_getspeed(unsigned int cpu) { int i = 0; unsigned long freq = clk_get_rate(armss_clk) / 1000; while (freq_table[i].frequency != CPUFREQ_TABLE_END) { if (freq <= freq_table[i].frequency) return freq_table[i].frequency; i++; } /* We could not find a corresponding frequency. */ pr_err("dbx500-cpufreq: Failed to find cpufreq speed\n"); return 0; } static int __cpuinit dbx500_cpufreq_init(struct cpufreq_policy *policy) { int res; /* get policy fields based on the table */ res = cpufreq_frequency_table_cpuinfo(policy, freq_table); if (!res) cpufreq_frequency_table_get_attr(freq_table, policy->cpu); else { pr_err("dbx500-cpufreq: Failed to read policy table\n"); return res; } policy->min = policy->cpuinfo.min_freq; policy->max = policy->cpuinfo.max_freq; policy->cur = dbx500_cpufreq_getspeed(policy->cpu); policy->governor = CPUFREQ_DEFAULT_GOVERNOR; /* * FIXME : Need to take time measurement across the target() * function with no/some/all drivers in the notification * list. */ policy->cpuinfo.transition_latency = 20 * 1000; /* in ns */ /* policy sharing between dual CPUs */ cpumask_setall(policy->cpus); return 0; } static struct cpufreq_driver dbx500_cpufreq_driver = { .flags = CPUFREQ_STICKY | CPUFREQ_CONST_LOOPS, .verify = dbx500_cpufreq_verify_speed, .target = dbx500_cpufreq_target, .get = dbx500_cpufreq_getspeed, .init = dbx500_cpufreq_init, .name = "DBX500", .attr = dbx500_cpufreq_attr, }; static int dbx500_cpufreq_probe(struct platform_device *pdev) { int i = 0; freq_table = dev_get_platdata(&pdev->dev); if (!freq_table) { pr_err("dbx500-cpufreq: Failed to fetch cpufreq table\n"); return -ENODEV; } armss_clk = clk_get(&pdev->dev, "armss"); if (IS_ERR(armss_clk)) { pr_err("dbx500-cpufreq: Failed to get armss clk\n"); return PTR_ERR(armss_clk); } pr_info("dbx500-cpufreq: Available frequencies:\n"); while (freq_table[i].frequency != CPUFREQ_TABLE_END) { pr_info(" %d Mhz\n", freq_table[i].frequency/1000); i++; } return cpufreq_register_driver(&dbx500_cpufreq_driver); } static struct platform_driver dbx500_cpufreq_plat_driver = { .driver = { .name = "cpufreq-ux500", .owner = THIS_MODULE, }, .probe = dbx500_cpufreq_probe, }; static int __init dbx500_cpufreq_register(void) { return platform_driver_register(&dbx500_cpufreq_plat_driver); } device_initcall(dbx500_cpufreq_register); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("cpufreq driver for DBX500");