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>

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");