@@ -24,18 +24,35 @@
#include "cpufreq-dt.h"
struct private_data {
- struct opp_table *opp_table;
+ cpumask_var_t cpus;
+ struct private_data *next;
+
struct device *cpu_dev;
- const char *reg_name;
+ struct opp_table *opp_table;
+ struct opp_table *reg_opp_table;
bool have_static_opps;
};
+static struct private_data *cpu_data;
+
static struct freq_attr *cpufreq_dt_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL, /* Extra space for boost-attr if required */
NULL,
};
+static struct private_data *cpufreq_dt_find_data(int cpu)
+{
+ struct private_data *priv = cpu_data;
+
+ while (priv) {
+ if (cpumask_test_cpu(cpu, priv->cpus))
+ break;
+ priv = priv->next;
+ }
+ return priv;
+}
+
static int set_target(struct cpufreq_policy *policy, unsigned int index)
{
struct private_data *priv = policy->driver_data;
@@ -90,83 +107,23 @@ static const char *find_supply_name(struct device *dev)
return name;
}
-static int resources_available(void)
-{
- struct device *cpu_dev;
- struct regulator *cpu_reg;
- struct clk *cpu_clk;
- int ret = 0;
- const char *name;
-
- cpu_dev = get_cpu_device(0);
- if (!cpu_dev) {
- pr_err("failed to get cpu0 device\n");
- return -ENODEV;
- }
-
- cpu_clk = clk_get(cpu_dev, NULL);
- ret = PTR_ERR_OR_ZERO(cpu_clk);
- if (ret) {
- /*
- * If cpu's clk node is present, but clock is not yet
- * registered, we should try defering probe.
- */
- if (ret == -EPROBE_DEFER)
- dev_dbg(cpu_dev, "clock not ready, retry\n");
- else
- dev_err(cpu_dev, "failed to get clock: %d\n", ret);
-
- return ret;
- }
-
- clk_put(cpu_clk);
-
- ret = dev_pm_opp_of_find_icc_paths(cpu_dev, NULL);
- if (ret)
- return ret;
-
- name = find_supply_name(cpu_dev);
- /* Platform doesn't require regulator */
- if (!name)
- return 0;
-
- cpu_reg = regulator_get_optional(cpu_dev, name);
- ret = PTR_ERR_OR_ZERO(cpu_reg);
- if (ret) {
- /*
- * If cpu's regulator supply node is present, but regulator is
- * not yet registered, we should try defering probe.
- */
- if (ret == -EPROBE_DEFER)
- dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n");
- else
- dev_dbg(cpu_dev, "no regulator for cpu0: %d\n", ret);
-
- return ret;
- }
-
- regulator_put(cpu_reg);
- return 0;
-}
-
static int cpufreq_init(struct cpufreq_policy *policy)
{
+ struct private_data *priv = cpufreq_dt_find_data(policy->cpu);
struct cpufreq_frequency_table *freq_table;
- struct opp_table *opp_table = NULL;
- struct private_data *priv;
struct device *cpu_dev;
struct clk *cpu_clk;
unsigned int transition_latency;
- bool fallback = false;
- const char *name;
int ret;
- cpu_dev = get_cpu_device(policy->cpu);
- if (!cpu_dev) {
- pr_err("failed to get cpu%d device\n", policy->cpu);
+ if (!priv) {
+ pr_err("failed to find data for cpu%d\n", policy->cpu);
return -ENODEV;
}
+ cpu_dev = priv->cpu_dev;
+ cpumask_copy(policy->cpus, priv->cpus);
+
cpu_clk = clk_get(cpu_dev, NULL);
if (IS_ERR(cpu_clk)) {
ret = PTR_ERR(cpu_clk);
@@ -174,45 +131,6 @@ static int cpufreq_init(struct cpufreq_policy *policy)
return ret;
}
- /* Get OPP-sharing information from "operating-points-v2" bindings */
- ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, policy->cpus);
- if (ret) {
- if (ret != -ENOENT)
- goto out_put_clk;
-
- /*
- * operating-points-v2 not supported, fallback to old method of
- * finding shared-OPPs for backward compatibility if the
- * platform hasn't set sharing CPUs.
- */
- if (dev_pm_opp_get_sharing_cpus(cpu_dev, policy->cpus))
- fallback = true;
- }
-
- /*
- * OPP layer will be taking care of regulators now, but it needs to know
- * the name of the regulator first.
- */
- name = find_supply_name(cpu_dev);
- if (name) {
- opp_table = dev_pm_opp_set_regulators(cpu_dev, &name, 1);
- if (IS_ERR(opp_table)) {
- ret = PTR_ERR(opp_table);
- dev_err(cpu_dev, "Failed to set regulator for cpu%d: %d\n",
- policy->cpu, ret);
- goto out_put_clk;
- }
- }
-
- priv = kzalloc(sizeof(*priv), GFP_KERNEL);
- if (!priv) {
- ret = -ENOMEM;
- goto out_put_regulator;
- }
-
- priv->reg_name = name;
- priv->opp_table = opp_table;
-
/*
* Initialize OPP tables for all policy->cpus. They will be shared by
* all CPUs which have marked their CPUs shared with OPP bindings.
@@ -237,26 +155,12 @@ static int cpufreq_init(struct cpufreq_policy *policy)
goto out_free_opp;
}
- if (fallback) {
- cpumask_setall(policy->cpus);
-
- /*
- * OPP tables are initialized only for policy->cpu, do it for
- * others as well.
- */
- ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
- if (ret)
- dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
- __func__, ret);
- }
-
ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
if (ret) {
dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
goto out_free_opp;
}
- priv->cpu_dev = cpu_dev;
policy->driver_data = priv;
policy->clk = cpu_clk;
policy->freq_table = freq_table;
@@ -288,11 +192,6 @@ static int cpufreq_init(struct cpufreq_policy *policy)
out_free_opp:
if (priv->have_static_opps)
dev_pm_opp_of_cpumask_remove_table(policy->cpus);
- kfree(priv);
-out_put_regulator:
- if (name)
- dev_pm_opp_put_regulators(opp_table);
-out_put_clk:
clk_put(cpu_clk);
return ret;
@@ -320,12 +219,7 @@ static int cpufreq_exit(struct cpufreq_policy *policy)
dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
if (priv->have_static_opps)
dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
- if (priv->reg_name)
- dev_pm_opp_put_regulators(priv->opp_table);
-
clk_put(policy->clk);
- kfree(priv);
-
return 0;
}
@@ -344,21 +238,112 @@ static struct cpufreq_driver dt_cpufreq_driver = {
.suspend = cpufreq_generic_suspend,
};
-static int dt_cpufreq_probe(struct platform_device *pdev)
+static int dt_cpufreq_init_cpu(struct device *dev, int cpu)
{
- struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev);
+ struct private_data *priv;
+ struct device *cpu_dev;
+ const char *reg_name;
int ret;
+ /* Check if this CPU is already covered by some other policy */
+ if (cpufreq_dt_find_data(cpu))
+ return 0;
+
+ cpu_dev = get_cpu_device(cpu);
+ if (!cpu_dev)
+ return -EPROBE_DEFER;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ if (!alloc_cpumask_var(&priv->cpus, GFP_KERNEL))
+ return -ENOMEM;
+
+ priv->cpu_dev = cpu_dev;
+ priv->next = cpu_data;
+ cpu_data = priv;
+
+ /* Try to get OPP table early to ensure resources are available */
+ priv->opp_table = dev_pm_opp_get_opp_table(cpu_dev);
+ if (IS_ERR(priv->opp_table)) {
+ ret = PTR_ERR(priv->opp_table);
+ if (ret != -EPROBE_DEFER)
+ dev_err(cpu_dev, "failed to get OPP table: %d\n", ret);
+ return ret;
+ }
+
/*
- * All per-cluster (CPUs sharing clock/voltages) initialization is done
- * from ->init(). In probe(), we just need to make sure that clk and
- * regulators are available. Else defer probe and retry.
- *
- * FIXME: Is checking this only for CPU0 sufficient ?
+ * OPP layer will be taking care of regulators now, but it needs to know
+ * the name of the regulator first.
*/
- ret = resources_available();
- if (ret)
- return ret;
+ reg_name = find_supply_name(cpu_dev);
+ if (reg_name) {
+ priv->reg_opp_table = dev_pm_opp_set_regulators(cpu_dev,
+ ®_name, 1);
+ if (IS_ERR(priv->reg_opp_table)) {
+ ret = PTR_ERR(priv->reg_opp_table);
+ if (ret != -EPROBE_DEFER)
+ dev_err(cpu_dev, "failed to set regulators: %d\n",
+ ret);
+ return ret;
+ }
+ }
+
+ /* Get OPP-sharing information from "operating-points-v2" bindings */
+ ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, priv->cpus);
+ if (ret) {
+ if (ret != -ENOENT)
+ return ret;
+
+ /*
+ * operating-points-v2 not supported, fallback to old method of
+ * finding shared-OPPs for backward compatibility if the
+ * platform hasn't set sharing CPUs.
+ */
+ if (dev_pm_opp_get_sharing_cpus(cpu_dev, priv->cpus)) {
+ /* Fallback to all CPUs */
+ cpumask_setall(priv->cpus);
+
+ /*
+ * OPP tables are initialized only for cpu, do it for
+ * others as well.
+ */
+ ret = dev_pm_opp_set_sharing_cpus(cpu_dev, priv->cpus);
+ if (ret)
+ dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
+ __func__, ret);
+ }
+ }
+
+ return 0;
+}
+
+static void dt_cpufreq_release(void)
+{
+ struct private_data *priv = cpu_data;
+
+ while (priv) {
+ if (!IS_ERR_OR_NULL(priv->reg_opp_table))
+ dev_pm_opp_put_regulators(priv->reg_opp_table);
+ if (!IS_ERR_OR_NULL(priv->opp_table))
+ dev_pm_opp_put_opp_table(priv->opp_table);
+ free_cpumask_var(priv->cpus);
+ priv = priv->next;
+ }
+ cpu_data = NULL;
+}
+
+static int dt_cpufreq_probe(struct platform_device *pdev)
+{
+ struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev);
+ int ret, cpu;
+
+ /* Request resources early so we can return in case of -EPROBE_DEFER */
+ for_each_possible_cpu(cpu) {
+ ret = dt_cpufreq_init_cpu(&pdev->dev, cpu);
+ if (ret)
+ goto err;
+ };
if (data) {
if (data->have_governor_per_policy)
@@ -374,15 +359,21 @@ static int dt_cpufreq_probe(struct platform_device *pdev)
}
ret = cpufreq_register_driver(&dt_cpufreq_driver);
- if (ret)
+ if (ret) {
dev_err(&pdev->dev, "failed register driver: %d\n", ret);
+ goto err;
+ }
+ return 0;
+err:
+ dt_cpufreq_release();
return ret;
}
static int dt_cpufreq_remove(struct platform_device *pdev)
{
cpufreq_unregister_driver(&dt_cpufreq_driver);
+ dt_cpufreq_release();
return 0;
}
cpufreq-dt is currently unable to handle -EPROBE_DEFER properly because the error code is not propagated for the cpufreq_driver->init() callback. Instead, it attempts to avoid the situation by temporarily requesting all resources within resources_available() and releasing them again immediately after. This has several disadvantages: - Whenever we add something like interconnect handling to the OPP core we need to patch cpufreq-dt to request these resources early. - resources_available() is only run for CPU0, but other clusters may eventually depend on other resources that are not available yet. (See FIXME comment removed by this commit...) - All resources need to be looked up several times. Now that the OPP core can propagate -EPROBE_DEFER during initialization, it would be nice to avoid all that trouble and just propagate its error code when necessary. This commit refactors the cpufreq-dt driver to initialize private_data before registering the cpufreq driver. We do this by iterating over all possible CPUs and ensure that all resources are initialized: 1. dev_pm_opp_get_opp_table() ensures the OPP table is allocated and initialized with clock and interconnects. 2. dev_pm_opp_set_regulators() requests the regulators and assigns them to the OPP table. 3. We call dev_pm_opp_of_get_sharing_cpus() early so that we only initialize the OPP table once for each shared policy. With these changes, we actually end up saving a few lines of code, the resources are no longer looked up multiple times and everything should be much more robust. Signed-off-by: Stephan Gerhold <stephan@gerhold.net> --- An alternative (and possibly more clean) solution would be to handle -EPROBE_DEFER for the cpufreq_driver->init() callback. However, this would require patching subsys_interface_register() to handle the return values of the subsys_interface->add_dev() callback (and rollback appropriately). The subsys functionality is used in a lot of places so I did not really feel comfortable changing that... --- drivers/cpufreq/cpufreq-dt.c | 275 +++++++++++++++++------------------ 1 file changed, 133 insertions(+), 142 deletions(-)