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Message-Id: <1373247868-21444-4-git-send-email-mturquette@linaro.org>
Date: Sun, 7 Jul 2013 18:44:28 -0700
From: Mike Turquette <mturquette@...aro.org>
To: linux-kernel@...r.kernel.org
Cc: linux-arm-kernel@...ts.infradead.org, linux-pm@...r.kernel.org,
Mike Turquette <mturquette@...aro.org>
Subject: [PATCH RFC 3/3] cpufreq: cpufreq-cpu0: clk rate-change notifiers
Removes direct handling of OPP tables and voltage regulators by calling
of_clk_cpufreq_notifier_handler, introduced by commit "clk: cpufreq
helper for voltage scaling".
In the future this can help consolidate code found across similar
CPUfreq drivers.
Signed-off-by: Mike Turquette <mturquette@...aro.org>
---
drivers/cpufreq/cpufreq-cpu0.c | 125 ++++++++---------------------------------
1 file changed, 22 insertions(+), 103 deletions(-)
diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
index ad1fde2..1e8f928 100644
--- a/drivers/cpufreq/cpufreq-cpu0.c
+++ b/drivers/cpufreq/cpufreq-cpu0.c
@@ -16,18 +16,15 @@
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of.h>
-#include <linux/opp.h>
#include <linux/platform_device.h>
-#include <linux/regulator/consumer.h>
#include <linux/slab.h>
static unsigned int transition_latency;
-static unsigned int voltage_tolerance; /* in percentage */
static struct device *cpu_dev;
static struct clk *cpu_clk;
-static struct regulator *cpu_reg;
static struct cpufreq_frequency_table *freq_table;
+static struct notifier_block *clk_nb;
static int cpu0_verify_speed(struct cpufreq_policy *policy)
{
@@ -43,8 +40,7 @@ static int cpu0_set_target(struct cpufreq_policy *policy,
unsigned int target_freq, unsigned int relation)
{
struct cpufreq_freqs freqs;
- struct opp *opp;
- unsigned long volt = 0, volt_old = 0, tol = 0;
+ unsigned long volt = 0, volt_old = 0;
long freq_Hz, freq_exact;
unsigned int index;
int ret;
@@ -69,56 +65,16 @@ static int cpu0_set_target(struct cpufreq_policy *policy,
cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
- if (cpu_reg) {
- rcu_read_lock();
- opp = opp_find_freq_ceil(cpu_dev, &freq_Hz);
- if (IS_ERR(opp)) {
- rcu_read_unlock();
- pr_err("failed to find OPP for %ld\n", freq_Hz);
- freqs.new = freqs.old;
- ret = PTR_ERR(opp);
- goto post_notify;
- }
- volt = opp_get_voltage(opp);
- rcu_read_unlock();
- tol = volt * voltage_tolerance / 100;
- volt_old = regulator_get_voltage(cpu_reg);
- }
-
pr_debug("%u MHz, %ld mV --> %u MHz, %ld mV\n",
freqs.old / 1000, volt_old ? volt_old / 1000 : -1,
freqs.new / 1000, volt ? volt / 1000 : -1);
- /* scaling up? scale voltage before frequency */
- if (cpu_reg && freqs.new > freqs.old) {
- ret = regulator_set_voltage_tol(cpu_reg, volt, tol);
- if (ret) {
- pr_err("failed to scale voltage up: %d\n", ret);
- freqs.new = freqs.old;
- goto post_notify;
- }
- }
-
ret = clk_set_rate(cpu_clk, freq_exact);
if (ret) {
pr_err("failed to set clock rate: %d\n", ret);
- if (cpu_reg)
- regulator_set_voltage_tol(cpu_reg, volt_old, tol);
freqs.new = freqs.old;
- goto post_notify;
- }
-
- /* scaling down? scale voltage after frequency */
- if (cpu_reg && freqs.new < freqs.old) {
- ret = regulator_set_voltage_tol(cpu_reg, volt, tol);
- if (ret) {
- pr_err("failed to scale voltage down: %d\n", ret);
- clk_set_rate(cpu_clk, freqs.old * 1000);
- freqs.new = freqs.old;
- }
}
-post_notify:
cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
return ret;
@@ -175,6 +131,7 @@ static struct cpufreq_driver cpu0_cpufreq_driver = {
static int cpu0_cpufreq_probe(struct platform_device *pdev)
{
struct device_node *np, *parent;
+ unsigned int voltage_latency;
int ret;
parent = of_find_node_by_path("/cpus");
@@ -197,22 +154,6 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
cpu_dev = &pdev->dev;
cpu_dev->of_node = np;
- cpu_reg = devm_regulator_get(cpu_dev, "cpu0");
- if (IS_ERR(cpu_reg)) {
- /*
- * If cpu0 regulator supply node is present, but regulator is
- * not yet registered, we should try defering probe.
- */
- if (PTR_ERR(cpu_reg) == -EPROBE_DEFER) {
- dev_err(cpu_dev, "cpu0 regulator not ready, retry\n");
- ret = -EPROBE_DEFER;
- goto out_put_node;
- }
- pr_warn("failed to get cpu0 regulator: %ld\n",
- PTR_ERR(cpu_reg));
- cpu_reg = NULL;
- }
-
cpu_clk = devm_clk_get(cpu_dev, NULL);
if (IS_ERR(cpu_clk)) {
ret = PTR_ERR(cpu_clk);
@@ -220,60 +161,38 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
goto out_put_node;
}
- ret = of_init_opp_table(cpu_dev);
- if (ret) {
- pr_err("failed to init OPP table: %d\n", ret);
- goto out_put_node;
- }
-
- ret = opp_init_cpufreq_table(cpu_dev, &freq_table);
- if (ret) {
- pr_err("failed to init cpufreq table: %d\n", ret);
- goto out_put_node;
- }
-
- of_property_read_u32(np, "voltage-tolerance", &voltage_tolerance);
-
if (of_property_read_u32(np, "clock-latency", &transition_latency))
transition_latency = CPUFREQ_ETERNAL;
- if (cpu_reg) {
- struct opp *opp;
- unsigned long min_uV, max_uV;
- int i;
-
- /*
- * OPP is maintained in order of increasing frequency, and
- * freq_table initialised from OPP is therefore sorted in the
- * same order.
- */
- for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++)
- ;
- rcu_read_lock();
- opp = opp_find_freq_exact(cpu_dev,
- freq_table[0].frequency * 1000, true);
- min_uV = opp_get_voltage(opp);
- opp = opp_find_freq_exact(cpu_dev,
- freq_table[i-1].frequency * 1000, true);
- max_uV = opp_get_voltage(opp);
- rcu_read_unlock();
- ret = regulator_set_voltage_time(cpu_reg, min_uV, max_uV);
- if (ret > 0)
- transition_latency += ret * 1000;
+ clk_nb = of_clk_cpufreq_notifier_register(cpu_dev, np, cpu_clk, "cpu0",
+ &freq_table, &voltage_latency);
+
+ if (IS_ERR(clk_nb)) {
+ ret = PTR_ERR(clk_nb);
+ /* defer probe if regulator is not yet registered */
+ if (ret == -EPROBE_DEFER)
+ dev_err(cpu_dev, "cpu0 clock notifier not ready, retry\n");
+ else
+ dev_err(cpu_dev, "failed to register cpu0 clock notifier: %d\n",
+ ret);
+ goto out_put_node;
}
+ if (voltage_latency > 0)
+ transition_latency += voltage_latency;
+
ret = cpufreq_register_driver(&cpu0_cpufreq_driver);
if (ret) {
pr_err("failed register driver: %d\n", ret);
- goto out_free_table;
+ goto out_notifier_unregister;
}
of_node_put(np);
of_node_put(parent);
return 0;
-out_free_table:
- opp_free_cpufreq_table(cpu_dev, &freq_table);
+out_notifier_unregister:
+ of_clk_cpufreq_notifier_unregister(clk_nb, freq_table);
out_put_node:
of_node_put(np);
out_put_parent:
@@ -283,8 +202,8 @@ out_put_parent:
static int cpu0_cpufreq_remove(struct platform_device *pdev)
{
+ of_clk_cpufreq_notifier_unregister(clk_nb, freq_table);
cpufreq_unregister_driver(&cpu0_cpufreq_driver);
- opp_free_cpufreq_table(cpu_dev, &freq_table);
return 0;
}
--
1.8.1.2
--
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