From fa5aec9561cfc4f4370983ca5818c90227c9d90e Mon Sep 17 00:00:00 2001 From: Andre Przywara Date: Thu, 18 Apr 2024 16:44:05 +0100 Subject: [PATCH] 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: Andre Przywara Reviewed-by: Jernej Skrabec Signed-off-by: Viresh Kumar --- drivers/cpufreq/sun50i-cpufreq-nvmem.c | 62 ++++++++++++++++++++++---- 1 file changed, 54 insertions(+), 8 deletions(-) --- a/drivers/cpufreq/sun50i-cpufreq-nvmem.c +++ b/drivers/cpufreq/sun50i-cpufreq-nvmem.c @@ -57,6 +57,41 @@ static const struct of_device_id cpu_opp }; /** + * 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 * * Returns non-negative speed bin index on success, a negative error @@ -109,7 +144,8 @@ static int sun50i_cpufreq_nvmem_probe(st { 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; @@ -124,7 +160,18 @@ static int sun50i_cpufreq_nvmem_probe(st 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); @@ -134,12 +181,11 @@ static int sun50i_cpufreq_nvmem_probe(st 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, @@ -154,7 +200,7 @@ static int sun50i_cpufreq_nvmem_probe(st 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; @@ -168,7 +214,7 @@ static int sun50i_cpufreq_nvmem_remove(s 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);