Add interrupt support to notify the kernel of h/w initiated frequency throttling by LMh. Convey this to scheduler via thermal presssure interface. Signed-off-by: Thara Gopinath <thara.gopinath@xxxxxxxxxx> --- v1->v2: - Introduced qcom_cpufreq_hw_lmh_init to consolidate LMh related initializations as per Viresh's review comment. - Moved the piece of code restarting polling/re-enabling LMh interrupt to qcom_lmh_dcvs_notify therby simplifying isr and timer callback as per Viresh's suggestion. - Droped cpus from qcom_cpufreq_data and instead using cpus from cpufreq_policy in qcom_lmh_dcvs_notify as per Viresh's review comment. - Dropped dt property qcom,support-lmh as per Bjorn's suggestion. - Other minor/cosmetic fixes drivers/cpufreq/qcom-cpufreq-hw.c | 103 ++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c index f86859bf76f1..241f6f2b441f 100644 --- a/drivers/cpufreq/qcom-cpufreq-hw.c +++ b/drivers/cpufreq/qcom-cpufreq-hw.c @@ -13,6 +13,7 @@ #include <linux/of_platform.h> #include <linux/pm_opp.h> #include <linux/slab.h> +#include <linux/interrupt.h> #define LUT_MAX_ENTRIES 40U #define LUT_SRC GENMASK(31, 30) @@ -22,10 +23,13 @@ #define CLK_HW_DIV 2 #define LUT_TURBO_IND 1 +#define HZ_PER_KHZ 1000 + struct qcom_cpufreq_soc_data { u32 reg_enable; u32 reg_freq_lut; u32 reg_volt_lut; + u32 reg_current_vote; u32 reg_perf_state; u8 lut_row_size; }; @@ -33,7 +37,10 @@ struct qcom_cpufreq_soc_data { struct qcom_cpufreq_data { void __iomem *base; struct resource *res; + struct delayed_work lmh_dcvs_poll_work; const struct qcom_cpufreq_soc_data *soc_data; + struct cpufreq_policy *policy; + int lmh_dcvs_irq; }; static unsigned long cpu_hw_rate, xo_rate; @@ -251,10 +258,79 @@ static void qcom_get_related_cpus(int index, struct cpumask *m) } } +static inline unsigned long qcom_lmh_vote_to_freq(u32 val) +{ + return (val & 0x3FF) * 19200; +} + +static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data) +{ + struct cpufreq_policy *policy = data->policy; + struct dev_pm_opp *opp; + struct device *dev; + unsigned long max_capacity, capacity, freq_hz, throttled_freq; + unsigned int val, freq; + + /* + * Get the h/w throttled frequency, normalize it using the + * registered opp table and use it to calculate thermal pressure. + */ + val = readl_relaxed(data->base + data->soc_data->reg_current_vote); + freq = qcom_lmh_vote_to_freq(val); + freq_hz = freq * HZ_PER_KHZ; + + dev = get_cpu_device(cpumask_first(policy->cpus)); + opp = dev_pm_opp_find_freq_floor(dev, &freq_hz); + if (IS_ERR(opp) && PTR_ERR(opp) == -ERANGE) + opp = dev_pm_opp_find_freq_ceil(dev, &freq_hz); + + throttled_freq = freq_hz / HZ_PER_KHZ; + + /* Update thermal pressure */ + max_capacity = arch_scale_cpu_capacity(cpumask_first(policy->cpus)); + capacity = throttled_freq * max_capacity; + capacity /= policy->cpuinfo.max_freq; + /* Don't pass boost capacity to scheduler */ + if (capacity > max_capacity) + capacity = max_capacity; + arch_set_thermal_pressure(policy->cpus, max_capacity - capacity); + /* + * If h/w throttled frequency is higher than what cpufreq has requested for, stop + * polling and switch back to interrupt mechanism + */ + if (throttled_freq >= qcom_cpufreq_hw_get(cpumask_first(policy->cpus))) + /* Clear the existing interrupts and enable it back */ + enable_irq(data->lmh_dcvs_irq); + else + mod_delayed_work(system_highpri_wq, &data->lmh_dcvs_poll_work, + msecs_to_jiffies(10)); +} + +static void qcom_lmh_dcvs_poll(struct work_struct *work) +{ + struct qcom_cpufreq_data *data; + + data = container_of(work, struct qcom_cpufreq_data, lmh_dcvs_poll_work.work); + + qcom_lmh_dcvs_notify(data); +} + +static irqreturn_t qcom_lmh_dcvs_handle_irq(int irq, void *data) +{ + struct qcom_cpufreq_data *c_data = data; + + /* Disable interrupt and enable polling */ + disable_irq_nosync(c_data->lmh_dcvs_irq); + qcom_lmh_dcvs_notify(c_data); + + return 0; +} + static const struct qcom_cpufreq_soc_data qcom_soc_data = { .reg_enable = 0x0, .reg_freq_lut = 0x110, .reg_volt_lut = 0x114, + .reg_current_vote = 0x704, .reg_perf_state = 0x920, .lut_row_size = 32, }; @@ -274,6 +350,23 @@ static const struct of_device_id qcom_cpufreq_hw_match[] = { }; MODULE_DEVICE_TABLE(of, qcom_cpufreq_hw_match); +static void qcom_cpufreq_hw_lmh_init(struct cpufreq_policy *policy) +{ + struct qcom_cpufreq_data *data = policy->driver_data; + struct platform_device *pdev = cpufreq_get_driver_data(); + struct device *dev = &pdev->dev; + int ret; + + ret = devm_request_irq(dev, data->lmh_dcvs_irq, qcom_lmh_dcvs_handle_irq, + 0, "dcvsh-irq", data); + if (ret) { + dev_err(dev, "Error %d registering irq %x\n", ret, data->lmh_dcvs_irq); + return; + } + data->policy = policy; + INIT_DEFERRABLE_WORK(&data->lmh_dcvs_poll_work, qcom_lmh_dcvs_poll); +} + static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy) { struct platform_device *pdev = cpufreq_get_driver_data(); @@ -370,6 +463,16 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy) dev_warn(cpu_dev, "failed to enable boost: %d\n", ret); } + /* Look for LMh interrupt. If no interrupt line is specified / + * if there is an error, allow cpufreq to be enabled as usual. + */ + data->lmh_dcvs_irq = platform_get_irq(pdev, index); + if (data->lmh_dcvs_irq > 0) { + qcom_cpufreq_hw_lmh_init(policy); + } else if (data->lmh_dcvs_irq != -ENXIO) { + ret = data->lmh_dcvs_irq; + goto error; + } return 0; error: kfree(data); -- 2.25.1