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authorLee Jones <lee.jones@linaro.org>2012-12-10 19:25:38 +0400
committerLinus Walleij <linus.walleij@linaro.org>2013-01-07 19:03:01 +0400
commitedb10c11c9af64efc8cdb001ada9792e0b2eef42 (patch)
tree8e076e21f54ece5545fe6db87c3916c813e23a42 /drivers/cpufreq/dbx500-cpufreq.c
parentd1c3ed669a2d452cacfb48c2d171a1f364dae2ed (diff)
downloadlinux-edb10c11c9af64efc8cdb001ada9792e0b2eef42.tar.xz
cpufreq: Give driver used for dbx500 family a more generic name
This driver doesn't only handle cpufreq functionality for the db8500 anymore. There are new variants which rely on it too. Let's make the name a bit more generic. Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/cpufreq/dbx500-cpufreq.c')
-rw-r--r--drivers/cpufreq/dbx500-cpufreq.c179
1 files changed, 179 insertions, 0 deletions
diff --git a/drivers/cpufreq/dbx500-cpufreq.c b/drivers/cpufreq/dbx500-cpufreq.c
new file mode 100644
index 000000000000..0a411b54972a
--- /dev/null
+++ b/drivers/cpufreq/dbx500-cpufreq.c
@@ -0,0 +1,179 @@
+/*
+ * Copyright (C) STMicroelectronics 2009
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * 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>
+#include <mach/id.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;
+
+ /* 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 */
+ for_each_cpu(freqs.cpu, policy->cpus)
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+ /* update armss clk frequency */
+ if (clk_set_rate(armss_clk, freq_table[idx].frequency * 1000)) {
+ pr_err("dbx500-cpufreq: Failed to update armss clk\n");
+ return -EINVAL;
+ }
+
+ /* 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;
+
+ 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 i = 0;
+ int res;
+
+ armss_clk = clk_get(NULL, "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++;
+ }
+
+ /* 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");
+ clk_put(armss_clk);
+ 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_copy(policy->cpus, cpu_present_mask);
+
+ policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
+
+ return 0;
+}
+
+static struct cpufreq_driver dbx500_cpufreq_driver = {
+ .flags = CPUFREQ_STICKY,
+ .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)
+{
+ freq_table = dev_get_platdata(&pdev->dev);
+
+ if (!freq_table) {
+ pr_err("dbx500-cpufreq: Failed to fetch cpufreq table\n");
+ return -ENODEV;
+ }
+
+ 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)
+{
+ if (!cpu_is_u8500_family())
+ return -ENODEV;
+
+ pr_info("cpufreq for DBX500 started\n");
+ return platform_driver_register(&dbx500_cpufreq_plat_driver);
+}
+device_initcall(dbx500_cpufreq_register);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("cpufreq driver for DBX500");