Commit fa5aec95 authored by Andre Przywara's avatar Andre Przywara Committed by Viresh Kumar
Browse files

cpufreq: sun50i: Add support for opp_supported_hw 



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: default avatarAndre Przywara <andre.przywara@arm.com>
Reviewed-by: default avatarJernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
parent 6cc4bcce

drivers/cpufreq/sun50i-cpufreq-nvmem.c

+54 −8
Original line number Diff line number Diff line
@@ -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);

}