Commit 275157b3 authored by Thara Gopinath's avatar Thara Gopinath Committed by Viresh Kumar
Browse files

cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support 



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: default avatarThara Gopinath <thara.gopinath@linaro.org>
[Viresh: Added changes for arch_topology.c to fix build errors ]
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
parent 37f18831

drivers/base/arch_topology.c

+2 −0
Original line number Diff line number Diff line
@@ -149,6 +149,7 @@ void topology_set_freq_scale(const struct cpumask *cpus, unsigned long cur_freq, 
}



DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;

EXPORT_PER_CPU_SYMBOL_GPL(cpu_scale);



void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)

{
@@ -165,6 +166,7 @@ void topology_set_thermal_pressure(const struct cpumask *cpus, 
	for_each_cpu(cpu, cpus)

		WRITE_ONCE(per_cpu(thermal_pressure, cpu), th_pressure);

}

EXPORT_SYMBOL_GPL(topology_set_thermal_pressure);



static ssize_t cpu_capacity_show(struct device *dev,

				 struct device_attribute *attr,

drivers/cpufreq/qcom-cpufreq-hw.c

+147 −0
Original line number Diff line number Diff line
@@ -7,12 +7,14 @@ 
#include <linux/cpufreq.h>

#include <linux/init.h>

#include <linux/interconnect.h>

#include <linux/interrupt.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/of_address.h>

#include <linux/of_platform.h>

#include <linux/pm_opp.h>

#include <linux/slab.h>

#include <linux/spinlock.h>



#define LUT_MAX_ENTRIES			40U

#define LUT_SRC				GENMASK(31, 30)
@@ -22,10 +24,13 @@ 
#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;

};
@@ -34,6 +39,16 @@ struct qcom_cpufreq_data { 
	void __iomem *base;

	struct resource *res;

	const struct qcom_cpufreq_soc_data *soc_data;



	/*

	 * Mutex to synchronize between de-init sequence and re-starting LMh

	 * polling/interrupts

	 */

	struct mutex throttle_lock;

	int throttle_irq;

	bool cancel_throttle;

	struct delayed_work throttle_work;

	struct cpufreq_policy *policy;

};



static unsigned long cpu_hw_rate, xo_rate;
@@ -251,10 +266,92 @@ static void qcom_get_related_cpus(int index, struct cpumask *m) 
	}

}



static unsigned int qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)

{

	unsigned int val = readl_relaxed(data->base + data->soc_data->reg_current_vote);



	return (val & 0x3FF) * 19200;

}



static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data)

{

	unsigned long max_capacity, capacity, freq_hz, throttled_freq;

	struct cpufreq_policy *policy = data->policy;

	int cpu = cpumask_first(policy->cpus);

	struct device *dev = get_cpu_device(cpu);

	struct dev_pm_opp *opp;

	unsigned int freq;



	/*

	 * Get the h/w throttled frequency, normalize it using the

	 * registered opp table and use it to calculate thermal pressure.

	 */

	freq = qcom_lmh_get_throttle_freq(data);

	freq_hz = freq * HZ_PER_KHZ;



	opp = dev_pm_opp_find_freq_floor(dev, &freq_hz);

	if (IS_ERR(opp) && PTR_ERR(opp) == -ERANGE)

		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(cpu);

	capacity = mult_frac(max_capacity, throttled_freq, 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);



	/*

	 * In the unlikely case policy is unregistered do not enable

	 * polling or h/w interrupt

	 */

	mutex_lock(&data->throttle_lock);

	if (data->cancel_throttle)

		goto out;



	/*

	 * If h/w throttled frequency is higher than what cpufreq has requested

	 * for, then stop polling and switch back to interrupt mechanism.

	 */

	if (throttled_freq >= qcom_cpufreq_hw_get(cpu))

		enable_irq(data->throttle_irq);

	else

		mod_delayed_work(system_highpri_wq, &data->throttle_work,

				 msecs_to_jiffies(10));



out:

	mutex_unlock(&data->throttle_lock);

}



static void qcom_lmh_dcvs_poll(struct work_struct *work)

{

	struct qcom_cpufreq_data *data;



	data = container_of(work, struct qcom_cpufreq_data, throttle_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->throttle_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 +371,51 @@ static const struct of_device_id qcom_cpufreq_hw_match[] = { 
};

MODULE_DEVICE_TABLE(of, qcom_cpufreq_hw_match);



static int qcom_cpufreq_hw_lmh_init(struct cpufreq_policy *policy, int index)

{

	struct qcom_cpufreq_data *data = policy->driver_data;

	struct platform_device *pdev = cpufreq_get_driver_data();

	char irq_name[15];

	int ret;



	/*

	 * Look for LMh interrupt. If no interrupt line is specified /

	 * if there is an error, allow cpufreq to be enabled as usual.

	 */

	data->throttle_irq = platform_get_irq(pdev, index);

	if (data->throttle_irq <= 0)

		return data->throttle_irq == -EPROBE_DEFER ? -EPROBE_DEFER : 0;



	data->cancel_throttle = false;

	data->policy = policy;



	mutex_init(&data->throttle_lock);

	INIT_DEFERRABLE_WORK(&data->throttle_work, qcom_lmh_dcvs_poll);



	snprintf(irq_name, sizeof(irq_name), "dcvsh-irq-%u", policy->cpu);

	ret = request_threaded_irq(data->throttle_irq, NULL, qcom_lmh_dcvs_handle_irq,

				   IRQF_ONESHOT, irq_name, data);

	if (ret) {

		dev_err(&pdev->dev, "Error registering %s: %d\n", irq_name, ret);

		return 0;

	}



	return 0;

}



static void qcom_cpufreq_hw_lmh_exit(struct qcom_cpufreq_data *data)

{

	if (data->throttle_irq <= 0)

		return;



	mutex_lock(&data->throttle_lock);

	data->cancel_throttle = true;

	mutex_unlock(&data->throttle_lock);



	cancel_delayed_work_sync(&data->throttle_work);

	free_irq(data->throttle_irq, data);

}



static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)

{

	struct platform_device *pdev = cpufreq_get_driver_data();
@@ -368,6 +510,10 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy) 
			dev_warn(cpu_dev, "failed to enable boost: %d\n", ret);

	}



	ret = qcom_cpufreq_hw_lmh_init(policy, index);

	if (ret)

		goto error;



	return 0;

error:

	kfree(data);
@@ -387,6 +533,7 @@ static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy) 


	dev_pm_opp_remove_all_dynamic(cpu_dev);

	dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);

	qcom_cpufreq_hw_lmh_exit(data);

	kfree(policy->freq_table);

	kfree(data);

	iounmap(base);