| /* |
| * Copyright (C) STMicroelectronics 2009 |
| * Copyright (C) ST-Ericsson SA 2010-2012 |
| * |
| * License Terms: GNU General Public License v2 |
| * Author: Sundar Iyer <sundar.iyer@stericsson.com> |
| * Author: Martin Persson <martin.persson@stericsson.com> |
| * Author: Jonas Aaberg <jonas.aberg@stericsson.com> |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/cpufreq.h> |
| #include <linux/delay.h> |
| #include <linux/slab.h> |
| #include <linux/platform_device.h> |
| #include <linux/clk.h> |
| |
| 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; |
| |
| /* 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 */ |
| for_each_cpu(freqs.cpu, policy->cpus) |
| cpufreq_notify_transition(&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 */ |
| for_each_cpu(freqs.cpu, policy->cpus) |
| cpufreq_notify_transition(&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; |
| |
| /* The value is rounded to closest frequency in the defined table. */ |
| while (freq_table[i + 1].frequency != CPUFREQ_TABLE_END) { |
| if (freq < freq_table[i].frequency + |
| (freq_table[i + 1].frequency - freq_table[i].frequency) / 2) |
| return freq_table[i].frequency; |
| i++; |
| } |
| |
| return freq_table[i].frequency; |
| } |
| |
| 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"); |