[PATCH 11/13] cpufreq: update DB8500 cpufreq driver

From: Linus Walleij
Date: Sat May 21 2011 - 04:44:00 EST


From: Linus Walleij <linus.walleij@xxxxxxxxxx>

This updates the ux500 cpufreq driver to the new interface from the
updated DB8500 PRCMU

Cc: Arnd Bergmann <arnd@xxxxxxxx>
Acked-by: Dave Jones <davej@xxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
drivers/cpufreq/db8500-cpufreq.c | 167 ++++++++++++++-----------------------
1 files changed, 63 insertions(+), 104 deletions(-)

diff --git a/drivers/cpufreq/db8500-cpufreq.c b/drivers/cpufreq/db8500-cpufreq.c
index d196939..d90456a 100644
--- a/drivers/cpufreq/db8500-cpufreq.c
+++ b/drivers/cpufreq/db8500-cpufreq.c
@@ -1,134 +1,118 @@
/*
- * CPU frequency scaling for u8500
- * Inspired by linux/arch/arm/mach-davinci/cpufreq.c
- *
* Copyright (C) STMicroelectronics 2009
* Copyright (C) ST-Ericsson SA 2010
*
* License Terms: GNU General Public License v2
- *
* Author: Sundar Iyer <sundar.iyer@xxxxxxxxxxxxxx>
* Author: Martin Persson <martin.persson@xxxxxxxxxxxxxx>
* Author: Jonas Aaberg <jonas.aberg@xxxxxxxxxxxxxx>
*
*/
-
-#include <linux/platform_device.h>
#include <linux/kernel.h>
#include <linux/cpufreq.h>
#include <linux/delay.h>
+#include <linux/slab.h>
#include <linux/mfd/db8500-prcmu.h>
-
-#include <mach/hardware.h>
-
-#define DRIVER_NAME "cpufreq-u8500"
-#define CPUFREQ_NAME "u8500"
-
-static struct device *dev;
+#include <mach/id.h>

static struct cpufreq_frequency_table freq_table[] = {
[0] = {
.index = 0,
- .frequency = 200000,
+ .frequency = 300000,
},
[1] = {
.index = 1,
- .frequency = 300000,
+ .frequency = 600000,
},
[2] = {
+ /* Used for MAX_OPP, if available */
.index = 2,
- .frequency = 600000,
+ .frequency = CPUFREQ_TABLE_END,
},
[3] = {
- /* Used for CPU_OPP_MAX, if available */
.index = 3,
.frequency = CPUFREQ_TABLE_END,
},
- [4] = {
- .index = 4,
- .frequency = CPUFREQ_TABLE_END,
- },
};

-static enum prcmu_cpu_opp index2opp[] = {
- CPU_OPP_EXT_CLK,
- CPU_OPP_50,
- CPU_OPP_100,
- CPU_OPP_MAX
+static enum arm_opp idx2opp[] = {
+ ARM_50_OPP,
+ ARM_100_OPP,
+ ARM_MAX_OPP
+};
+
+static struct freq_attr *db8500_cpufreq_attr[] = {
+ &cpufreq_freq_attr_scaling_available_freqs,
+ NULL,
};

-static int u8500_cpufreq_verify_speed(struct cpufreq_policy *policy)
+static int db8500_cpufreq_verify_speed(struct cpufreq_policy *policy)
{
return cpufreq_frequency_table_verify(policy, freq_table);
}

-static int u8500_cpufreq_target(struct cpufreq_policy *policy,
+static int db8500_cpufreq_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
struct cpufreq_freqs freqs;
- unsigned int index;
- int ret = 0;
+ unsigned int idx;

- /*
- * Ensure desired rate is within allowed range. Some govenors
- * (ondemand) will just pass target_freq=0 to get the minimum.
- */
+ /* 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;

- ret = cpufreq_frequency_table_target(policy, freq_table,
- target_freq, relation, &index);
- if (ret < 0) {
- dev_err(dev, "Could not look up next frequency\n");
- return 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[index].frequency;
+ freqs.new = freq_table[idx].frequency;
freqs.cpu = policy->cpu;

- if (freqs.old == freqs.new) {
- dev_dbg(dev, "Current and target frequencies are equal\n");
+ if (freqs.old == freqs.new)
return 0;
- }

- dev_dbg(dev, "transition: %u --> %u\n", freqs.old, freqs.new);
+ /* pre-change notification */
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

- ret = prcmu_set_cpu_opp(index2opp[index]);
- if (ret < 0) {
- dev_err(dev, "Failed to set OPP level\n");
- return ret;
+ /* request the PRCM unit for opp change */
+ if (prcmu_set_arm_opp(idx2opp[idx])) {
+ pr_err("db8500-cpufreq: Failed to set OPP level\n");
+ return -EINVAL;
}

+ /* post change notification */
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

- return ret;
+ return 0;
}

-static unsigned int u8500_cpufreq_getspeed(unsigned int cpu)
+static unsigned int db8500_cpufreq_getspeed(unsigned int cpu)
{
int i;
-
- for (i = 0; prcmu_get_cpu_opp() != index2opp[i]; i++)
+ /* request the prcm to get the current ARM opp */
+ for (i = 0; prcmu_get_arm_opp() != idx2opp[i]; i++)
;
return freq_table[i].frequency;
}

-static int __cpuinit u8500_cpu_init(struct cpufreq_policy *policy)
+static int __cpuinit db8500_cpufreq_init(struct cpufreq_policy *policy)
{
int res;
+ int i;

- BUILD_BUG_ON(ARRAY_SIZE(index2opp) + 1 != ARRAY_SIZE(freq_table));
+ BUILD_BUG_ON(ARRAY_SIZE(idx2opp) + 1 != ARRAY_SIZE(freq_table));

- if (cpu_is_u8500v2()) {
- freq_table[1].frequency = 400000;
- freq_table[2].frequency = 800000;
+ if (cpu_is_u8500v2() && !prcmu_is_u8400()) {
+ freq_table[0].frequency = 400000;
+ freq_table[1].frequency = 800000;
if (prcmu_has_arm_maxopp())
- freq_table[3].frequency = 1000000;
+ freq_table[2].frequency = 1000000;
}

/* get policy fields based on the table */
@@ -136,13 +120,17 @@ static int __cpuinit u8500_cpu_init(struct cpufreq_policy *policy)
if (!res)
cpufreq_frequency_table_get_attr(freq_table, policy->cpu);
else {
- dev_err(dev, "u8500-cpufreq : Failed to read policy table\n");
+ pr_err("db8500-cpufreq : Failed to read policy table\n");
return res;
}

policy->min = policy->cpuinfo.min_freq;
policy->max = policy->cpuinfo.max_freq;
- policy->cur = u8500_cpufreq_getspeed(policy->cpu);
+ policy->cur = db8500_cpufreq_getspeed(policy->cpu);
+
+ for (i = 0; freq_table[i].frequency != policy->cur; i++)
+ ;
+
policy->governor = CPUFREQ_DEFAULT_GOVERNOR;

/*
@@ -150,61 +138,32 @@ static int __cpuinit u8500_cpu_init(struct cpufreq_policy *policy)
* function with no/some/all drivers in the notification
* list.
*/
- policy->cpuinfo.transition_latency = 200 * 1000; /* in ns */
+ policy->cpuinfo.transition_latency = 20 * 1000; /* in ns */

/* policy sharing between dual CPUs */
cpumask_copy(policy->cpus, &cpu_present_map);

policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;

- return res;
-}
-
-static struct freq_attr *u8500_cpufreq_attr[] = {
- &cpufreq_freq_attr_scaling_available_freqs,
- NULL,
-};
-static int u8500_cpu_exit(struct cpufreq_policy *policy)
-{
- cpufreq_frequency_table_put_attr(policy->cpu);
return 0;
}

-static struct cpufreq_driver u8500_driver = {
- .owner = THIS_MODULE,
- .flags = CPUFREQ_STICKY,
- .verify = u8500_cpufreq_verify_speed,
- .target = u8500_cpufreq_target,
- .get = u8500_cpufreq_getspeed,
- .init = u8500_cpu_init,
- .exit = u8500_cpu_exit,
- .name = CPUFREQ_NAME,
- .attr = u8500_cpufreq_attr,
+static struct cpufreq_driver db8500_cpufreq_driver = {
+ .flags = CPUFREQ_STICKY,
+ .verify = db8500_cpufreq_verify_speed,
+ .target = db8500_cpufreq_target,
+ .get = db8500_cpufreq_getspeed,
+ .init = db8500_cpufreq_init,
+ .name = "DB8500",
+ .attr = db8500_cpufreq_attr,
};

-static int __init u8500_cpufreq_probe(struct platform_device *pdev)
+static int __init db8500_cpufreq_register(void)
{
- dev = &pdev->dev;
- return cpufreq_register_driver(&u8500_driver);
-}
-
-static int __exit u8500_cpufreq_remove(struct platform_device *pdev)
-{
- return cpufreq_unregister_driver(&u8500_driver);
-}
+ if (!cpu_is_u8500v20_or_later())
+ return -ENODEV;

-static struct platform_driver u8500_cpufreq_driver = {
- .driver = {
- .name = DRIVER_NAME,
- .owner = THIS_MODULE,
- },
- .remove = __exit_p(u8500_cpufreq_remove),
-};
-
-static int __init u8500_cpufreq_init(void)
-{
- return platform_driver_probe(&u8500_cpufreq_driver,
- &u8500_cpufreq_probe);
+ pr_info("cpufreq for DB8500 started\n");
+ return cpufreq_register_driver(&db8500_cpufreq_driver);
}
-
-device_initcall(u8500_cpufreq_init);
+device_initcall(db8500_cpufreq_register);
--
1.7.3.2

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