1 files changed, 733 insertions, 0 deletions

diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
new file mode 100644
index 000000000..749b60c78
--- /dev/null
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -0,0 +1,733 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/bitfield.h>
+#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>
+#include <linux/units.h>
+
+#define LUT_MAX_ENTRIES			40U
+#define LUT_SRC				GENMASK(31, 30)
+#define LUT_L_VAL			GENMASK(7, 0)
+#define LUT_CORE_COUNT			GENMASK(18, 16)
+#define LUT_VOLT			GENMASK(11, 0)
+#define CLK_HW_DIV			2
+#define LUT_TURBO_IND			1
+
+#define GT_IRQ_STATUS			BIT(2)
+
+struct qcom_cpufreq_soc_data {
+	u32 reg_enable;
+	u32 reg_domain_state;
+	u32 reg_dcvs_ctrl;
+	u32 reg_freq_lut;
+	u32 reg_volt_lut;
+	u32 reg_intr_clr;
+	u32 reg_current_vote;
+	u32 reg_perf_state;
+	u8 lut_row_size;
+};
+
+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;
+	char irq_name[15];
+	bool cancel_throttle;
+	struct delayed_work throttle_work;
+	struct cpufreq_policy *policy;
+
+	bool per_core_dcvs;
+};
+
+static unsigned long cpu_hw_rate, xo_rate;
+static bool icc_scaling_enabled;
+
+static int qcom_cpufreq_set_bw(struct cpufreq_policy *policy,
+			       unsigned long freq_khz)
+{
+	unsigned long freq_hz = freq_khz * 1000;
+	struct dev_pm_opp *opp;
+	struct device *dev;
+	int ret;
+
+	dev = get_cpu_device(policy->cpu);
+	if (!dev)
+		return -ENODEV;
+
+	opp = dev_pm_opp_find_freq_exact(dev, freq_hz, true);
+	if (IS_ERR(opp))
+		return PTR_ERR(opp);
+
+	ret = dev_pm_opp_set_opp(dev, opp);
+	dev_pm_opp_put(opp);
+	return ret;
+}
+
+static int qcom_cpufreq_update_opp(struct device *cpu_dev,
+				   unsigned long freq_khz,
+				   unsigned long volt)
+{
+	unsigned long freq_hz = freq_khz * 1000;
+	int ret;
+
+	/* Skip voltage update if the opp table is not available */
+	if (!icc_scaling_enabled)
+		return dev_pm_opp_add(cpu_dev, freq_hz, volt);
+
+	ret = dev_pm_opp_adjust_voltage(cpu_dev, freq_hz, volt, volt, volt);
+	if (ret) {
+		dev_err(cpu_dev, "Voltage update failed freq=%ld\n", freq_khz);
+		return ret;
+	}
+
+	return dev_pm_opp_enable(cpu_dev, freq_hz);
+}
+
+static int qcom_cpufreq_hw_target_index(struct cpufreq_policy *policy,
+					unsigned int index)
+{
+	struct qcom_cpufreq_data *data = policy->driver_data;
+	const struct qcom_cpufreq_soc_data *soc_data = data->soc_data;
+	unsigned long freq = policy->freq_table[index].frequency;
+	unsigned int i;
+
+	writel_relaxed(index, data->base + soc_data->reg_perf_state);
+
+	if (data->per_core_dcvs)
+		for (i = 1; i < cpumask_weight(policy->related_cpus); i++)
+			writel_relaxed(index, data->base + soc_data->reg_perf_state + i * 4);
+
+	if (icc_scaling_enabled)
+		qcom_cpufreq_set_bw(policy, freq);
+
+	return 0;
+}
+
+static unsigned long qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
+{
+	unsigned int lval;
+
+	if (data->soc_data->reg_current_vote)
+		lval = readl_relaxed(data->base + data->soc_data->reg_current_vote) & 0x3ff;
+	else
+		lval = readl_relaxed(data->base + data->soc_data->reg_domain_state) & 0xff;
+
+	return lval * xo_rate;
+}
+
+/* Get the frequency requested by the cpufreq core for the CPU */
+static unsigned int qcom_cpufreq_get_freq(unsigned int cpu)
+{
+	struct qcom_cpufreq_data *data;
+	const struct qcom_cpufreq_soc_data *soc_data;
+	struct cpufreq_policy *policy;
+	unsigned int index;
+
+	policy = cpufreq_cpu_get_raw(cpu);
+	if (!policy)
+		return 0;
+
+	data = policy->driver_data;
+	soc_data = data->soc_data;
+
+	index = readl_relaxed(data->base + soc_data->reg_perf_state);
+	index = min(index, LUT_MAX_ENTRIES - 1);
+
+	return policy->freq_table[index].frequency;
+}
+
+static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
+{
+	struct qcom_cpufreq_data *data;
+	struct cpufreq_policy *policy;
+
+	policy = cpufreq_cpu_get_raw(cpu);
+	if (!policy)
+		return 0;
+
+	data = policy->driver_data;
+
+	if (data->throttle_irq >= 0)
+		return qcom_lmh_get_throttle_freq(data) / HZ_PER_KHZ;
+
+	return qcom_cpufreq_get_freq(cpu);
+}
+
+static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
+						unsigned int target_freq)
+{
+	struct qcom_cpufreq_data *data = policy->driver_data;
+	const struct qcom_cpufreq_soc_data *soc_data = data->soc_data;
+	unsigned int index;
+	unsigned int i;
+
+	index = policy->cached_resolved_idx;
+	writel_relaxed(index, data->base + soc_data->reg_perf_state);
+
+	if (data->per_core_dcvs)
+		for (i = 1; i < cpumask_weight(policy->related_cpus); i++)
+			writel_relaxed(index, data->base + soc_data->reg_perf_state + i * 4);
+
+	return policy->freq_table[index].frequency;
+}
+
+static int qcom_cpufreq_hw_read_lut(struct device *cpu_dev,
+				    struct cpufreq_policy *policy)
+{
+	u32 data, src, lval, i, core_count, prev_freq = 0, freq;
+	u32 volt;
+	struct cpufreq_frequency_table	*table;
+	struct dev_pm_opp *opp;
+	unsigned long rate;
+	int ret;
+	struct qcom_cpufreq_data *drv_data = policy->driver_data;
+	const struct qcom_cpufreq_soc_data *soc_data = drv_data->soc_data;
+
+	table = kcalloc(LUT_MAX_ENTRIES + 1, sizeof(*table), GFP_KERNEL);
+	if (!table)
+		return -ENOMEM;
+
+	ret = dev_pm_opp_of_add_table(cpu_dev);
+	if (!ret) {
+		/* Disable all opps and cross-validate against LUT later */
+		icc_scaling_enabled = true;
+		for (rate = 0; ; rate++) {
+			opp = dev_pm_opp_find_freq_ceil(cpu_dev, &rate);
+			if (IS_ERR(opp))
+				break;
+
+			dev_pm_opp_put(opp);
+			dev_pm_opp_disable(cpu_dev, rate);
+		}
+	} else if (ret != -ENODEV) {
+		dev_err(cpu_dev, "Invalid opp table in device tree\n");
+		kfree(table);
+		return ret;
+	} else {
+		policy->fast_switch_possible = true;
+		icc_scaling_enabled = false;
+	}
+
+	for (i = 0; i < LUT_MAX_ENTRIES; i++) {
+		data = readl_relaxed(drv_data->base + soc_data->reg_freq_lut +
+				      i * soc_data->lut_row_size);
+		src = FIELD_GET(LUT_SRC, data);
+		lval = FIELD_GET(LUT_L_VAL, data);
+		core_count = FIELD_GET(LUT_CORE_COUNT, data);
+
+		data = readl_relaxed(drv_data->base + soc_data->reg_volt_lut +
+				      i * soc_data->lut_row_size);
+		volt = FIELD_GET(LUT_VOLT, data) * 1000;
+
+		if (src)
+			freq = xo_rate * lval / 1000;
+		else
+			freq = cpu_hw_rate / 1000;
+
+		if (freq != prev_freq && core_count != LUT_TURBO_IND) {
+			if (!qcom_cpufreq_update_opp(cpu_dev, freq, volt)) {
+				table[i].frequency = freq;
+				dev_dbg(cpu_dev, "index=%d freq=%d, core_count %d\n", i,
+				freq, core_count);
+			} else {
+				dev_warn(cpu_dev, "failed to update OPP for freq=%d\n", freq);
+				table[i].frequency = CPUFREQ_ENTRY_INVALID;
+			}
+
+		} else if (core_count == LUT_TURBO_IND) {
+			table[i].frequency = CPUFREQ_ENTRY_INVALID;
+		}
+
+		/*
+		 * Two of the same frequencies with the same core counts means
+		 * end of table
+		 */
+		if (i > 0 && prev_freq == freq) {
+			struct cpufreq_frequency_table *prev = &table[i - 1];
+
+			/*
+			 * Only treat the last frequency that might be a boost
+			 * as the boost frequency
+			 */
+			if (prev->frequency == CPUFREQ_ENTRY_INVALID) {
+				if (!qcom_cpufreq_update_opp(cpu_dev, prev_freq, volt)) {
+					prev->frequency = prev_freq;
+					prev->flags = CPUFREQ_BOOST_FREQ;
+				} else {
+					dev_warn(cpu_dev, "failed to update OPP for freq=%d\n",
+						 freq);
+				}
+			}
+
+			break;
+		}
+
+		prev_freq = freq;
+	}
+
+	table[i].frequency = CPUFREQ_TABLE_END;
+	policy->freq_table = table;
+	dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
+
+	return 0;
+}
+
+static void qcom_get_related_cpus(int index, struct cpumask *m)
+{
+	struct device_node *cpu_np;
+	struct of_phandle_args args;
+	int cpu, ret;
+
+	for_each_possible_cpu(cpu) {
+		cpu_np = of_cpu_device_node_get(cpu);
+		if (!cpu_np)
+			continue;
+
+		ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
+						 "#freq-domain-cells", 0,
+						 &args);
+		of_node_put(cpu_np);
+		if (ret < 0)
+			continue;
+
+		if (index == args.args[0])
+			cpumask_set_cpu(cpu, m);
+	}
+}
+
+static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data)
+{
+	struct cpufreq_policy *policy = data->policy;
+	int cpu = cpumask_first(policy->related_cpus);
+	struct device *dev = get_cpu_device(cpu);
+	unsigned long freq_hz, throttled_freq;
+	struct dev_pm_opp *opp;
+
+	/*
+	 * Get the h/w throttled frequency, normalize it using the
+	 * registered opp table and use it to calculate thermal pressure.
+	 */
+	freq_hz = qcom_lmh_get_throttle_freq(data);
+
+	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);
+
+	if (IS_ERR(opp)) {
+		dev_warn(dev, "Can't find the OPP for throttling: %pe!\n", opp);
+	} else {
+		dev_pm_opp_put(opp);
+	}
+
+	throttled_freq = freq_hz / HZ_PER_KHZ;
+
+	/* Update thermal pressure (the boost frequencies are accepted) */
+	arch_update_thermal_pressure(policy->related_cpus, throttled_freq);
+
+	/*
+	 * 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_get_freq(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);
+	schedule_delayed_work(&c_data->throttle_work, 0);
+
+	if (c_data->soc_data->reg_intr_clr)
+		writel_relaxed(GT_IRQ_STATUS,
+			       c_data->base + c_data->soc_data->reg_intr_clr);
+
+	return IRQ_HANDLED;
+}
+
+static const struct qcom_cpufreq_soc_data qcom_soc_data = {
+	.reg_enable = 0x0,
+	.reg_dcvs_ctrl = 0xbc,
+	.reg_freq_lut = 0x110,
+	.reg_volt_lut = 0x114,
+	.reg_current_vote = 0x704,
+	.reg_perf_state = 0x920,
+	.lut_row_size = 32,
+};
+
+static const struct qcom_cpufreq_soc_data epss_soc_data = {
+	.reg_enable = 0x0,
+	.reg_domain_state = 0x20,
+	.reg_dcvs_ctrl = 0xb0,
+	.reg_freq_lut = 0x100,
+	.reg_volt_lut = 0x200,
+	.reg_intr_clr = 0x308,
+	.reg_perf_state = 0x320,
+	.lut_row_size = 4,
+};
+
+static const struct of_device_id qcom_cpufreq_hw_match[] = {
+	{ .compatible = "qcom,cpufreq-hw", .data = &qcom_soc_data },
+	{ .compatible = "qcom,cpufreq-epss", .data = &epss_soc_data },
+	{}
+};
+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();
+	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_optional(pdev, index);
+	if (data->throttle_irq == -ENXIO)
+		return 0;
+	if (data->throttle_irq < 0)
+		return data->throttle_irq;
+
+	data->cancel_throttle = false;
+	data->policy = policy;
+
+	mutex_init(&data->throttle_lock);
+	INIT_DEFERRABLE_WORK(&data->throttle_work, qcom_lmh_dcvs_poll);
+
+	snprintf(data->irq_name, sizeof(data->irq_name), "dcvsh-irq-%u", policy->cpu);
+	ret = request_threaded_irq(data->throttle_irq, NULL, qcom_lmh_dcvs_handle_irq,
+				   IRQF_ONESHOT | IRQF_NO_AUTOEN, data->irq_name, data);
+	if (ret) {
+		dev_err(&pdev->dev, "Error registering %s: %d\n", data->irq_name, ret);
+		return 0;
+	}
+
+	ret = irq_set_affinity_and_hint(data->throttle_irq, policy->cpus);
+	if (ret)
+		dev_err(&pdev->dev, "Failed to set CPU affinity of %s[%d]\n",
+			data->irq_name, data->throttle_irq);
+
+	return 0;
+}
+
+static int qcom_cpufreq_hw_cpu_online(struct cpufreq_policy *policy)
+{
+	struct qcom_cpufreq_data *data = policy->driver_data;
+	struct platform_device *pdev = cpufreq_get_driver_data();
+	int ret;
+
+	if (data->throttle_irq <= 0)
+		return 0;
+
+	mutex_lock(&data->throttle_lock);
+	data->cancel_throttle = false;
+	mutex_unlock(&data->throttle_lock);
+
+	ret = irq_set_affinity_and_hint(data->throttle_irq, policy->cpus);
+	if (ret)
+		dev_err(&pdev->dev, "Failed to set CPU affinity of %s[%d]\n",
+			data->irq_name, data->throttle_irq);
+
+	return ret;
+}
+
+static int qcom_cpufreq_hw_cpu_offline(struct cpufreq_policy *policy)
+{
+	struct qcom_cpufreq_data *data = policy->driver_data;
+
+	if (data->throttle_irq <= 0)
+		return 0;
+
+	mutex_lock(&data->throttle_lock);
+	data->cancel_throttle = true;
+	mutex_unlock(&data->throttle_lock);
+
+	cancel_delayed_work_sync(&data->throttle_work);
+	irq_set_affinity_and_hint(data->throttle_irq, NULL);
+	disable_irq_nosync(data->throttle_irq);
+
+	return 0;
+}
+
+static void qcom_cpufreq_hw_lmh_exit(struct qcom_cpufreq_data *data)
+{
+	if (data->throttle_irq <= 0)
+		return;
+
+	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();
+	struct device *dev = &pdev->dev;
+	struct of_phandle_args args;
+	struct device_node *cpu_np;
+	struct device *cpu_dev;
+	struct resource *res;
+	void __iomem *base;
+	struct qcom_cpufreq_data *data;
+	int ret, index;
+
+	cpu_dev = get_cpu_device(policy->cpu);
+	if (!cpu_dev) {
+		pr_err("%s: failed to get cpu%d device\n", __func__,
+		       policy->cpu);
+		return -ENODEV;
+	}
+
+	cpu_np = of_cpu_device_node_get(policy->cpu);
+	if (!cpu_np)
+		return -EINVAL;
+
+	ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
+					 "#freq-domain-cells", 0, &args);
+	of_node_put(cpu_np);
+	if (ret)
+		return ret;
+
+	index = args.args[0];
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, index);
+	if (!res) {
+		dev_err(dev, "failed to get mem resource %d\n", index);
+		return -ENODEV;
+	}
+
+	if (!request_mem_region(res->start, resource_size(res), res->name)) {
+		dev_err(dev, "failed to request resource %pR\n", res);
+		return -EBUSY;
+	}
+
+	base = ioremap(res->start, resource_size(res));
+	if (!base) {
+		dev_err(dev, "failed to map resource %pR\n", res);
+		ret = -ENOMEM;
+		goto release_region;
+	}
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		ret = -ENOMEM;
+		goto unmap_base;
+	}
+
+	data->soc_data = of_device_get_match_data(&pdev->dev);
+	data->base = base;
+	data->res = res;
+
+	/* HW should be in enabled state to proceed */
+	if (!(readl_relaxed(base + data->soc_data->reg_enable) & 0x1)) {
+		dev_err(dev, "Domain-%d cpufreq hardware not enabled\n", index);
+		ret = -ENODEV;
+		goto error;
+	}
+
+	if (readl_relaxed(base + data->soc_data->reg_dcvs_ctrl) & 0x1)
+		data->per_core_dcvs = true;
+
+	qcom_get_related_cpus(index, policy->cpus);
+	if (cpumask_empty(policy->cpus)) {
+		dev_err(dev, "Domain-%d failed to get related CPUs\n", index);
+		ret = -ENOENT;
+		goto error;
+	}
+
+	policy->driver_data = data;
+	policy->dvfs_possible_from_any_cpu = true;
+
+	ret = qcom_cpufreq_hw_read_lut(cpu_dev, policy);
+	if (ret) {
+		dev_err(dev, "Domain-%d failed to read LUT\n", index);
+		goto error;
+	}
+
+	ret = dev_pm_opp_get_opp_count(cpu_dev);
+	if (ret <= 0) {
+		dev_err(cpu_dev, "Failed to add OPPs\n");
+		ret = -ENODEV;
+		goto error;
+	}
+
+	if (policy_has_boost_freq(policy)) {
+		ret = cpufreq_enable_boost_support();
+		if (ret)
+			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);
+unmap_base:
+	iounmap(base);
+release_region:
+	release_mem_region(res->start, resource_size(res));
+	return ret;
+}
+
+static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
+{
+	struct device *cpu_dev = get_cpu_device(policy->cpu);
+	struct qcom_cpufreq_data *data = policy->driver_data;
+	struct resource *res = data->res;
+	void __iomem *base = data->base;
+
+	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);
+	release_mem_region(res->start, resource_size(res));
+
+	return 0;
+}
+
+static void qcom_cpufreq_ready(struct cpufreq_policy *policy)
+{
+	struct qcom_cpufreq_data *data = policy->driver_data;
+
+	if (data->throttle_irq >= 0)
+		enable_irq(data->throttle_irq);
+}
+
+static struct freq_attr *qcom_cpufreq_hw_attr[] = {
+	&cpufreq_freq_attr_scaling_available_freqs,
+	&cpufreq_freq_attr_scaling_boost_freqs,
+	NULL
+};
+
+static struct cpufreq_driver cpufreq_qcom_hw_driver = {
+	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK |
+			  CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
+			  CPUFREQ_IS_COOLING_DEV,
+	.verify		= cpufreq_generic_frequency_table_verify,
+	.target_index	= qcom_cpufreq_hw_target_index,
+	.get		= qcom_cpufreq_hw_get,
+	.init		= qcom_cpufreq_hw_cpu_init,
+	.exit		= qcom_cpufreq_hw_cpu_exit,
+	.online		= qcom_cpufreq_hw_cpu_online,
+	.offline	= qcom_cpufreq_hw_cpu_offline,
+	.register_em	= cpufreq_register_em_with_opp,
+	.fast_switch    = qcom_cpufreq_hw_fast_switch,
+	.name		= "qcom-cpufreq-hw",
+	.attr		= qcom_cpufreq_hw_attr,
+	.ready		= qcom_cpufreq_ready,
+};
+
+static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev)
+{
+	struct device *cpu_dev;
+	struct clk *clk;
+	int ret;
+
+	clk = clk_get(&pdev->dev, "xo");
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	xo_rate = clk_get_rate(clk);
+	clk_put(clk);
+
+	clk = clk_get(&pdev->dev, "alternate");
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	cpu_hw_rate = clk_get_rate(clk) / CLK_HW_DIV;
+	clk_put(clk);
+
+	cpufreq_qcom_hw_driver.driver_data = pdev;
+
+	/* Check for optional interconnect paths on CPU0 */
+	cpu_dev = get_cpu_device(0);
+	if (!cpu_dev)
+		return -EPROBE_DEFER;
+
+	ret = dev_pm_opp_of_find_icc_paths(cpu_dev, NULL);
+	if (ret)
+		return ret;
+
+	ret = cpufreq_register_driver(&cpufreq_qcom_hw_driver);
+	if (ret)
+		dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n");
+	else
+		dev_dbg(&pdev->dev, "QCOM CPUFreq HW driver initialized\n");
+
+	return ret;
+}
+
+static int qcom_cpufreq_hw_driver_remove(struct platform_device *pdev)
+{
+	return cpufreq_unregister_driver(&cpufreq_qcom_hw_driver);
+}
+
+static struct platform_driver qcom_cpufreq_hw_driver = {
+	.probe = qcom_cpufreq_hw_driver_probe,
+	.remove = qcom_cpufreq_hw_driver_remove,
+	.driver = {
+		.name = "qcom-cpufreq-hw",
+		.of_match_table = qcom_cpufreq_hw_match,
+	},
+};
+
+static int __init qcom_cpufreq_hw_init(void)
+{
+	return platform_driver_register(&qcom_cpufreq_hw_driver);
+}
+postcore_initcall(qcom_cpufreq_hw_init);
+
+static void __exit qcom_cpufreq_hw_exit(void)
+{
+	platform_driver_unregister(&qcom_cpufreq_hw_driver);
+}
+module_exit(qcom_cpufreq_hw_exit);
+
+MODULE_DESCRIPTION("QCOM CPUFREQ HW Driver");
+MODULE_LICENSE("GPL v2");