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cpufreq: sun50i: Add support for opp_supported_hw

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The opp_supported_hw DT property allows the DT to specify a mask of chip
revisions that a certain OPP is eligible for. This allows for easy
limiting of maximum frequencies, for instance.

Add support for that in the sun50i-cpufreq-nvmem driver. We support both
the existing opp-microvolt suffix properties as well as the
opp-supported-hw property, the generic code figures out which is needed
automatically.
However if none of the DT OPP nodes contain an opp-supported-hw
property, the core code will ignore all OPPs and the driver will fail
probing. So check the DT's eligibility first before using that feature.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
This commit is contained in:
Andre Przywara 2024-04-18 16:44:05 +01:00 committed by Viresh Kumar
parent 6cc4bcceff
commit fa5aec9561
1 changed files with 54 additions and 8 deletions
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62
drivers/cpufreq/sun50i-cpufreq-nvmem.c
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@ -57,6 +57,41 @@ static const struct of_device_id cpu_opp_match_list[] = {
{}
};
/**
* dt_has_supported_hw() - Check if any OPPs use opp-supported-hw
*
* If we ask the cpufreq framework to use the opp-supported-hw feature, it
* will ignore every OPP node without that DT property. If none of the OPPs
* have it, the driver will fail probing, due to the lack of OPPs.
*
* Returns true if we have at least one OPP with the opp-supported-hw property.
*/
static bool dt_has_supported_hw(void)
{
bool has_opp_supported_hw = false;
struct device_node *np, *opp;
struct device *cpu_dev;
cpu_dev = get_cpu_device(0);
if (!cpu_dev)
return -ENODEV;
np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
if (!np)
return -ENOENT;
for_each_child_of_node(np, opp) {
if (of_find_property(opp, "opp-supported-hw", NULL)) {
has_opp_supported_hw = true;
break;
}
}
of_node_put(np);
return has_opp_supported_hw;
}
/**
* sun50i_cpufreq_get_efuse() - Determine speed grade from efuse value
*
@ -110,7 +145,8 @@ static int sun50i_cpufreq_nvmem_probe(struct platform_device *pdev)
{
int *opp_tokens;
char name[MAX_NAME_LEN];
unsigned int cpu;
unsigned int cpu, supported_hw;
struct dev_pm_opp_config config = {};
int speed;
int ret;
@ -125,7 +161,18 @@ static int sun50i_cpufreq_nvmem_probe(struct platform_device *pdev)
return speed;
}
/*
* We need at least one OPP with the "opp-supported-hw" property,
* or else the upper layers will ignore every OPP and will bail out.
*/
if (dt_has_supported_hw()) {
supported_hw = 1U << speed;
config.supported_hw = &supported_hw;
config.supported_hw_count = 1;
}
snprintf(name, MAX_NAME_LEN, "speed%d", speed);
config.prop_name = name;
for_each_possible_cpu(cpu) {
struct device *cpu_dev = get_cpu_device(cpu);
@ -135,12 +182,11 @@ static int sun50i_cpufreq_nvmem_probe(struct platform_device *pdev)
goto free_opp;
}
opp_tokens[cpu] = dev_pm_opp_set_prop_name(cpu_dev, name);
if (opp_tokens[cpu] < 0) {
ret = opp_tokens[cpu];
pr_err("Failed to set prop name\n");
ret = dev_pm_opp_set_config(cpu_dev, &config);
if (ret < 0)
goto free_opp;
}
opp_tokens[cpu] = ret;
}
cpufreq_dt_pdev = platform_device_register_simple("cpufreq-dt", -1,
@ -155,7 +201,7 @@ static int sun50i_cpufreq_nvmem_probe(struct platform_device *pdev)
free_opp:
for_each_possible_cpu(cpu)
dev_pm_opp_put_prop_name(opp_tokens[cpu]);
dev_pm_opp_clear_config(opp_tokens[cpu]);
kfree(opp_tokens);
return ret;
@ -169,7 +215,7 @@ static void sun50i_cpufreq_nvmem_remove(struct platform_device *pdev)
platform_device_unregister(cpufreq_dt_pdev);
for_each_possible_cpu(cpu)
dev_pm_opp_put_prop_name(opp_tokens[cpu]);
dev_pm_opp_clear_config(opp_tokens[cpu]);
kfree(opp_tokens);
}