[PATCH 2/3] cpufreq: merge arm_big_little and vexpress-spc

From: Sudeep Holla
Date: Wed Oct 16 2019 - 07:03:57 EST


arm_big_little cpufreq driver was designed as a generic big little
driver that could be used by any platform and make use of bL switcher.
Over years alternate solutions have be designed and merged to deal with
bL/HMP systems like EAS.

Also since no other driver made use of generic arm_big_little cpufreq
driver except Vexpress SPC, we can merge them together as vexpress-spc
driver used only on Vexpress TC2(CA15_CA7) platform.

Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
---
MAINTAINERS | 5 +-
drivers/cpufreq/Kconfig.arm | 12 +-
drivers/cpufreq/Makefile | 2 -
drivers/cpufreq/arm_big_little.c | 658 ------------------------
drivers/cpufreq/arm_big_little.h | 43 --
drivers/cpufreq/vexpress-spc-cpufreq.c | 661 ++++++++++++++++++++++++-
6 files changed, 652 insertions(+), 729 deletions(-)
delete mode 100644 drivers/cpufreq/arm_big_little.c
delete mode 100644 drivers/cpufreq/arm_big_little.h

diff --git a/MAINTAINERS b/MAINTAINERS
index a69e6db80c79..78a4adff7892 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4269,14 +4269,13 @@ F: include/linux/cpufreq.h
F: include/linux/sched/cpufreq.h
F: tools/testing/selftests/cpufreq/

-CPU FREQUENCY DRIVERS - ARM BIG LITTLE
+CPU FREQUENCY DRIVERS - VEXPRESS SPC ARM BIG LITTLE
M: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
M: Sudeep Holla <sudeep.holla@xxxxxxx>
L: linux-pm@xxxxxxxxxxxxxxx
W: http://www.arm.com/products/processors/technologies/biglittleprocessing.php
S: Maintained
-F: drivers/cpufreq/arm_big_little.h
-F: drivers/cpufreq/arm_big_little.c
+F: drivers/cpufreq/vexpress-spc-cpufreq.c

CPU POWER MONITORING SUBSYSTEM
M: Thomas Renninger <trenn@xxxxxxxx>
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index a905796f7f85..3858d86cf409 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -49,14 +49,6 @@ config ARM_ARMADA_8K_CPUFREQ

If in doubt, say N.

-# big LITTLE core layer and glue drivers
-config ARM_BIG_LITTLE_CPUFREQ
- tristate "Generic ARM big LITTLE CPUfreq driver"
- depends on ARM_CPU_TOPOLOGY && HAVE_CLK
- select PM_OPP
- help
- This enables the Generic CPUfreq driver for ARM big.LITTLE platforms.
-
config ARM_SCPI_CPUFREQ
tristate "SCPI based CPUfreq driver"
depends on ARM_SCPI_PROTOCOL && COMMON_CLK_SCPI
@@ -69,7 +61,9 @@ config ARM_SCPI_CPUFREQ

config ARM_VEXPRESS_SPC_CPUFREQ
tristate "Versatile Express SPC based CPUfreq driver"
- depends on ARM_BIG_LITTLE_CPUFREQ && ARCH_VEXPRESS_SPC
+ depends on ARM_CPU_TOPOLOGY && HAVE_CLK
+ depends on ARCH_VEXPRESS_SPC
+ select PM_OPP
help
This add the CPUfreq driver support for Versatile Express
big.LITTLE platforms using SPC for power management.
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 9a9f5ccd13d9..f6670c4abbb0 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -47,8 +47,6 @@ obj-$(CONFIG_X86_SFI_CPUFREQ) += sfi-cpufreq.o

##################################################################################
# ARM SoC drivers
-obj-$(CONFIG_ARM_BIG_LITTLE_CPUFREQ) += arm_big_little.o
-
obj-$(CONFIG_ARM_ARMADA_37XX_CPUFREQ) += armada-37xx-cpufreq.o
obj-$(CONFIG_ARM_ARMADA_8K_CPUFREQ) += armada-8k-cpufreq.o
obj-$(CONFIG_ARM_BRCMSTB_AVS_CPUFREQ) += brcmstb-avs-cpufreq.o
diff --git a/drivers/cpufreq/arm_big_little.c b/drivers/cpufreq/arm_big_little.c
deleted file mode 100644
index 7fe52fcddcf1..000000000000
--- a/drivers/cpufreq/arm_big_little.c
+++ /dev/null
@@ -1,658 +0,0 @@
-/*
- * ARM big.LITTLE Platforms CPUFreq support
- *
- * Copyright (C) 2013 ARM Ltd.
- * Sudeep KarkadaNagesha <sudeep.karkadanagesha@xxxxxxx>
- *
- * Copyright (C) 2013 Linaro.
- * Viresh Kumar <viresh.kumar@xxxxxxxxxx>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed "as is" WITHOUT ANY WARRANTY of any
- * kind, whether express or implied; without even the implied warranty
- * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/clk.h>
-#include <linux/cpu.h>
-#include <linux/cpufreq.h>
-#include <linux/cpumask.h>
-#include <linux/cpu_cooling.h>
-#include <linux/export.h>
-#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/of_platform.h>
-#include <linux/pm_opp.h>
-#include <linux/slab.h>
-#include <linux/topology.h>
-#include <linux/types.h>
-
-#include "arm_big_little.h"
-
-/* Currently we support only two clusters */
-#define A15_CLUSTER 0
-#define A7_CLUSTER 1
-#define MAX_CLUSTERS 2
-
-#ifdef CONFIG_BL_SWITCHER
-#include <asm/bL_switcher.h>
-static bool bL_switching_enabled;
-#define is_bL_switching_enabled() bL_switching_enabled
-#define set_switching_enabled(x) (bL_switching_enabled = (x))
-#else
-#define is_bL_switching_enabled() false
-#define set_switching_enabled(x) do { } while (0)
-#define bL_switch_request(...) do { } while (0)
-#define bL_switcher_put_enabled() do { } while (0)
-#define bL_switcher_get_enabled() do { } while (0)
-#endif
-
-#define ACTUAL_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq << 1 : freq)
-#define VIRT_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq >> 1 : freq)
-
-static struct thermal_cooling_device *cdev[MAX_CLUSTERS];
-static const struct cpufreq_arm_bL_ops *arm_bL_ops;
-static struct clk *clk[MAX_CLUSTERS];
-static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
-static atomic_t cluster_usage[MAX_CLUSTERS + 1];
-
-static unsigned int clk_big_min; /* (Big) clock frequencies */
-static unsigned int clk_little_max; /* Maximum clock frequency (Little) */
-
-static DEFINE_PER_CPU(unsigned int, physical_cluster);
-static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq);
-
-static struct mutex cluster_lock[MAX_CLUSTERS];
-
-static inline int raw_cpu_to_cluster(int cpu)
-{
- return topology_physical_package_id(cpu);
-}
-
-static inline int cpu_to_cluster(int cpu)
-{
- return is_bL_switching_enabled() ?
- MAX_CLUSTERS : raw_cpu_to_cluster(cpu);
-}
-
-static unsigned int find_cluster_maxfreq(int cluster)
-{
- int j;
- u32 max_freq = 0, cpu_freq;
-
- for_each_online_cpu(j) {
- cpu_freq = per_cpu(cpu_last_req_freq, j);
-
- if ((cluster == per_cpu(physical_cluster, j)) &&
- (max_freq < cpu_freq))
- max_freq = cpu_freq;
- }
-
- pr_debug("%s: cluster: %d, max freq: %d\n", __func__, cluster,
- max_freq);
-
- return max_freq;
-}
-
-static unsigned int clk_get_cpu_rate(unsigned int cpu)
-{
- u32 cur_cluster = per_cpu(physical_cluster, cpu);
- u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;
-
- /* For switcher we use virtual A7 clock rates */
- if (is_bL_switching_enabled())
- rate = VIRT_FREQ(cur_cluster, rate);
-
- pr_debug("%s: cpu: %d, cluster: %d, freq: %u\n", __func__, cpu,
- cur_cluster, rate);
-
- return rate;
-}
-
-static unsigned int bL_cpufreq_get_rate(unsigned int cpu)
-{
- if (is_bL_switching_enabled()) {
- pr_debug("%s: freq: %d\n", __func__, per_cpu(cpu_last_req_freq,
- cpu));
-
- return per_cpu(cpu_last_req_freq, cpu);
- } else {
- return clk_get_cpu_rate(cpu);
- }
-}
-
-static unsigned int
-bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
-{
- u32 new_rate, prev_rate;
- int ret;
- bool bLs = is_bL_switching_enabled();
-
- mutex_lock(&cluster_lock[new_cluster]);
-
- if (bLs) {
- prev_rate = per_cpu(cpu_last_req_freq, cpu);
- per_cpu(cpu_last_req_freq, cpu) = rate;
- per_cpu(physical_cluster, cpu) = new_cluster;
-
- new_rate = find_cluster_maxfreq(new_cluster);
- new_rate = ACTUAL_FREQ(new_cluster, new_rate);
- } else {
- new_rate = rate;
- }
-
- pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n",
- __func__, cpu, old_cluster, new_cluster, new_rate);
-
- ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
- if (!ret) {
- /*
- * FIXME: clk_set_rate hasn't returned an error here however it
- * may be that clk_change_rate failed due to hardware or
- * firmware issues and wasn't able to report that due to the
- * current design of the clk core layer. To work around this
- * problem we will read back the clock rate and check it is
- * correct. This needs to be removed once clk core is fixed.
- */
- if (clk_get_rate(clk[new_cluster]) != new_rate * 1000)
- ret = -EIO;
- }
-
- if (WARN_ON(ret)) {
- pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
- new_cluster);
- if (bLs) {
- per_cpu(cpu_last_req_freq, cpu) = prev_rate;
- per_cpu(physical_cluster, cpu) = old_cluster;
- }
-
- mutex_unlock(&cluster_lock[new_cluster]);
-
- return ret;
- }
-
- mutex_unlock(&cluster_lock[new_cluster]);
-
- /* Recalc freq for old cluster when switching clusters */
- if (old_cluster != new_cluster) {
- pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n",
- __func__, cpu, old_cluster, new_cluster);
-
- /* Switch cluster */
- bL_switch_request(cpu, new_cluster);
-
- mutex_lock(&cluster_lock[old_cluster]);
-
- /* Set freq of old cluster if there are cpus left on it */
- new_rate = find_cluster_maxfreq(old_cluster);
- new_rate = ACTUAL_FREQ(old_cluster, new_rate);
-
- if (new_rate) {
- pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
- __func__, old_cluster, new_rate);
-
- if (clk_set_rate(clk[old_cluster], new_rate * 1000))
- pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
- __func__, ret, old_cluster);
- }
- mutex_unlock(&cluster_lock[old_cluster]);
- }
-
- return 0;
-}
-
-/* Set clock frequency */
-static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
- unsigned int index)
-{
- u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
- unsigned int freqs_new;
- int ret;
-
- cur_cluster = cpu_to_cluster(cpu);
- new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
-
- freqs_new = freq_table[cur_cluster][index].frequency;
-
- if (is_bL_switching_enabled()) {
- if ((actual_cluster == A15_CLUSTER) &&
- (freqs_new < clk_big_min)) {
- new_cluster = A7_CLUSTER;
- } else if ((actual_cluster == A7_CLUSTER) &&
- (freqs_new > clk_little_max)) {
- new_cluster = A15_CLUSTER;
- }
- }
-
- ret = bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
-
- if (!ret) {
- arch_set_freq_scale(policy->related_cpus, freqs_new,
- policy->cpuinfo.max_freq);
- }
-
- return ret;
-}
-
-static inline u32 get_table_count(struct cpufreq_frequency_table *table)
-{
- int count;
-
- for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
- ;
-
- return count;
-}
-
-/* get the minimum frequency in the cpufreq_frequency_table */
-static inline u32 get_table_min(struct cpufreq_frequency_table *table)
-{
- struct cpufreq_frequency_table *pos;
- uint32_t min_freq = ~0;
- cpufreq_for_each_entry(pos, table)
- if (pos->frequency < min_freq)
- min_freq = pos->frequency;
- return min_freq;
-}
-
-/* get the maximum frequency in the cpufreq_frequency_table */
-static inline u32 get_table_max(struct cpufreq_frequency_table *table)
-{
- struct cpufreq_frequency_table *pos;
- uint32_t max_freq = 0;
- cpufreq_for_each_entry(pos, table)
- if (pos->frequency > max_freq)
- max_freq = pos->frequency;
- return max_freq;
-}
-
-static int merge_cluster_tables(void)
-{
- int i, j, k = 0, count = 1;
- struct cpufreq_frequency_table *table;
-
- for (i = 0; i < MAX_CLUSTERS; i++)
- count += get_table_count(freq_table[i]);
-
- table = kcalloc(count, sizeof(*table), GFP_KERNEL);
- if (!table)
- return -ENOMEM;
-
- freq_table[MAX_CLUSTERS] = table;
-
- /* Add in reverse order to get freqs in increasing order */
- for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
- for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
- j++) {
- table[k].frequency = VIRT_FREQ(i,
- freq_table[i][j].frequency);
- pr_debug("%s: index: %d, freq: %d\n", __func__, k,
- table[k].frequency);
- k++;
- }
- }
-
- table[k].driver_data = k;
- table[k].frequency = CPUFREQ_TABLE_END;
-
- pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
-
- return 0;
-}
-
-static void _put_cluster_clk_and_freq_table(struct device *cpu_dev,
- const struct cpumask *cpumask)
-{
- u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
-
- if (!freq_table[cluster])
- return;
-
- clk_put(clk[cluster]);
- dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
- if (arm_bL_ops->free_opp_table)
- arm_bL_ops->free_opp_table(cpumask);
- dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
-}
-
-static void put_cluster_clk_and_freq_table(struct device *cpu_dev,
- const struct cpumask *cpumask)
-{
- u32 cluster = cpu_to_cluster(cpu_dev->id);
- int i;
-
- if (atomic_dec_return(&cluster_usage[cluster]))
- return;
-
- if (cluster < MAX_CLUSTERS)
- return _put_cluster_clk_and_freq_table(cpu_dev, cpumask);
-
- for_each_present_cpu(i) {
- struct device *cdev = get_cpu_device(i);
- if (!cdev) {
- pr_err("%s: failed to get cpu%d device\n", __func__, i);
- return;
- }
-
- _put_cluster_clk_and_freq_table(cdev, cpumask);
- }
-
- /* free virtual table */
- kfree(freq_table[cluster]);
-}
-
-static int _get_cluster_clk_and_freq_table(struct device *cpu_dev,
- const struct cpumask *cpumask)
-{
- u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
- int ret;
-
- if (freq_table[cluster])
- return 0;
-
- ret = arm_bL_ops->init_opp_table(cpumask);
- if (ret) {
- dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
- __func__, cpu_dev->id, ret);
- goto out;
- }
-
- ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
- if (ret) {
- dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
- __func__, cpu_dev->id, ret);
- goto free_opp_table;
- }
-
- clk[cluster] = clk_get(cpu_dev, NULL);
- if (!IS_ERR(clk[cluster])) {
- dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
- __func__, clk[cluster], freq_table[cluster],
- cluster);
- return 0;
- }
-
- dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
- __func__, cpu_dev->id, cluster);
- ret = PTR_ERR(clk[cluster]);
- dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
-
-free_opp_table:
- if (arm_bL_ops->free_opp_table)
- arm_bL_ops->free_opp_table(cpumask);
-out:
- dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
- cluster);
- return ret;
-}
-
-static int get_cluster_clk_and_freq_table(struct device *cpu_dev,
- const struct cpumask *cpumask)
-{
- u32 cluster = cpu_to_cluster(cpu_dev->id);
- int i, ret;
-
- if (atomic_inc_return(&cluster_usage[cluster]) != 1)
- return 0;
-
- if (cluster < MAX_CLUSTERS) {
- ret = _get_cluster_clk_and_freq_table(cpu_dev, cpumask);
- if (ret)
- atomic_dec(&cluster_usage[cluster]);
- return ret;
- }
-
- /*
- * Get data for all clusters and fill virtual cluster with a merge of
- * both
- */
- for_each_present_cpu(i) {
- struct device *cdev = get_cpu_device(i);
- if (!cdev) {
- pr_err("%s: failed to get cpu%d device\n", __func__, i);
- return -ENODEV;
- }
-
- ret = _get_cluster_clk_and_freq_table(cdev, cpumask);
- if (ret)
- goto put_clusters;
- }
-
- ret = merge_cluster_tables();
- if (ret)
- goto put_clusters;
-
- /* Assuming 2 cluster, set clk_big_min and clk_little_max */
- clk_big_min = get_table_min(freq_table[0]);
- clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
-
- pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
- __func__, cluster, clk_big_min, clk_little_max);
-
- return 0;
-
-put_clusters:
- for_each_present_cpu(i) {
- struct device *cdev = get_cpu_device(i);
- if (!cdev) {
- pr_err("%s: failed to get cpu%d device\n", __func__, i);
- return -ENODEV;
- }
-
- _put_cluster_clk_and_freq_table(cdev, cpumask);
- }
-
- atomic_dec(&cluster_usage[cluster]);
-
- return ret;
-}
-
-/* Per-CPU initialization */
-static int bL_cpufreq_init(struct cpufreq_policy *policy)
-{
- u32 cur_cluster = cpu_to_cluster(policy->cpu);
- struct device *cpu_dev;
- int ret;
-
- 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;
- }
-
- if (cur_cluster < MAX_CLUSTERS) {
- int cpu;
-
- cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
-
- for_each_cpu(cpu, policy->cpus)
- per_cpu(physical_cluster, cpu) = cur_cluster;
- } else {
- /* Assumption: during init, we are always running on A15 */
- per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
- }
-
- ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
- if (ret)
- return ret;
-
- policy->freq_table = freq_table[cur_cluster];
- policy->cpuinfo.transition_latency =
- arm_bL_ops->get_transition_latency(cpu_dev);
-
- dev_pm_opp_of_register_em(policy->cpus);
-
- if (is_bL_switching_enabled())
- per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);
-
- dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
- return 0;
-}
-
-static int bL_cpufreq_exit(struct cpufreq_policy *policy)
-{
- struct device *cpu_dev;
- int cur_cluster = cpu_to_cluster(policy->cpu);
-
- if (cur_cluster < MAX_CLUSTERS) {
- cpufreq_cooling_unregister(cdev[cur_cluster]);
- cdev[cur_cluster] = NULL;
- }
-
- 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;
- }
-
- put_cluster_clk_and_freq_table(cpu_dev, policy->related_cpus);
- dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
-
- return 0;
-}
-
-static void bL_cpufreq_ready(struct cpufreq_policy *policy)
-{
- int cur_cluster = cpu_to_cluster(policy->cpu);
-
- /* Do not register a cpu_cooling device if we are in IKS mode */
- if (cur_cluster >= MAX_CLUSTERS)
- return;
-
- cdev[cur_cluster] = of_cpufreq_cooling_register(policy);
-}
-
-static struct cpufreq_driver bL_cpufreq_driver = {
- .name = "arm-big-little",
- .flags = CPUFREQ_STICKY |
- CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
- CPUFREQ_NEED_INITIAL_FREQ_CHECK,
- .verify = cpufreq_generic_frequency_table_verify,
- .target_index = bL_cpufreq_set_target,
- .get = bL_cpufreq_get_rate,
- .init = bL_cpufreq_init,
- .exit = bL_cpufreq_exit,
- .ready = bL_cpufreq_ready,
- .attr = cpufreq_generic_attr,
-};
-
-#ifdef CONFIG_BL_SWITCHER
-static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
- unsigned long action, void *_arg)
-{
- pr_debug("%s: action: %ld\n", __func__, action);
-
- switch (action) {
- case BL_NOTIFY_PRE_ENABLE:
- case BL_NOTIFY_PRE_DISABLE:
- cpufreq_unregister_driver(&bL_cpufreq_driver);
- break;
-
- case BL_NOTIFY_POST_ENABLE:
- set_switching_enabled(true);
- cpufreq_register_driver(&bL_cpufreq_driver);
- break;
-
- case BL_NOTIFY_POST_DISABLE:
- set_switching_enabled(false);
- cpufreq_register_driver(&bL_cpufreq_driver);
- break;
-
- default:
- return NOTIFY_DONE;
- }
-
- return NOTIFY_OK;
-}
-
-static struct notifier_block bL_switcher_notifier = {
- .notifier_call = bL_cpufreq_switcher_notifier,
-};
-
-static int __bLs_register_notifier(void)
-{
- return bL_switcher_register_notifier(&bL_switcher_notifier);
-}
-
-static int __bLs_unregister_notifier(void)
-{
- return bL_switcher_unregister_notifier(&bL_switcher_notifier);
-}
-#else
-static int __bLs_register_notifier(void) { return 0; }
-static int __bLs_unregister_notifier(void) { return 0; }
-#endif
-
-int bL_cpufreq_register(const struct cpufreq_arm_bL_ops *ops)
-{
- int ret, i;
-
- if (arm_bL_ops) {
- pr_debug("%s: Already registered: %s, exiting\n", __func__,
- arm_bL_ops->name);
- return -EBUSY;
- }
-
- if (!ops || !strlen(ops->name) || !ops->init_opp_table ||
- !ops->get_transition_latency) {
- pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
- return -ENODEV;
- }
-
- arm_bL_ops = ops;
-
- set_switching_enabled(bL_switcher_get_enabled());
-
- for (i = 0; i < MAX_CLUSTERS; i++)
- mutex_init(&cluster_lock[i]);
-
- ret = cpufreq_register_driver(&bL_cpufreq_driver);
- if (ret) {
- pr_info("%s: Failed registering platform driver: %s, err: %d\n",
- __func__, ops->name, ret);
- arm_bL_ops = NULL;
- } else {
- ret = __bLs_register_notifier();
- if (ret) {
- cpufreq_unregister_driver(&bL_cpufreq_driver);
- arm_bL_ops = NULL;
- } else {
- pr_info("%s: Registered platform driver: %s\n",
- __func__, ops->name);
- }
- }
-
- bL_switcher_put_enabled();
- return ret;
-}
-EXPORT_SYMBOL_GPL(bL_cpufreq_register);
-
-void bL_cpufreq_unregister(const struct cpufreq_arm_bL_ops *ops)
-{
- if (arm_bL_ops != ops) {
- pr_err("%s: Registered with: %s, can't unregister, exiting\n",
- __func__, arm_bL_ops->name);
- return;
- }
-
- bL_switcher_get_enabled();
- __bLs_unregister_notifier();
- cpufreq_unregister_driver(&bL_cpufreq_driver);
- bL_switcher_put_enabled();
- pr_info("%s: Un-registered platform driver: %s\n", __func__,
- arm_bL_ops->name);
- arm_bL_ops = NULL;
-}
-EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);
-
-MODULE_AUTHOR("Viresh Kumar <viresh.kumar@xxxxxxxxxx>");
-MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver");
-MODULE_LICENSE("GPL v2");
diff --git a/drivers/cpufreq/arm_big_little.h b/drivers/cpufreq/arm_big_little.h
deleted file mode 100644
index 88a176e466c8..000000000000
--- a/drivers/cpufreq/arm_big_little.h
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * ARM big.LITTLE platform's CPUFreq header file
- *
- * Copyright (C) 2013 ARM Ltd.
- * Sudeep KarkadaNagesha <sudeep.karkadanagesha@xxxxxxx>
- *
- * Copyright (C) 2013 Linaro.
- * Viresh Kumar <viresh.kumar@xxxxxxxxxx>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed "as is" WITHOUT ANY WARRANTY of any
- * kind, whether express or implied; without even the implied warranty
- * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
-#ifndef CPUFREQ_ARM_BIG_LITTLE_H
-#define CPUFREQ_ARM_BIG_LITTLE_H
-
-#include <linux/cpufreq.h>
-#include <linux/device.h>
-#include <linux/types.h>
-
-struct cpufreq_arm_bL_ops {
- char name[CPUFREQ_NAME_LEN];
-
- /*
- * This must set opp table for cpu_dev in a similar way as done by
- * dev_pm_opp_of_add_table().
- */
- int (*init_opp_table)(const struct cpumask *cpumask);
-
- /* Optional */
- int (*get_transition_latency)(struct device *cpu_dev);
- void (*free_opp_table)(const struct cpumask *cpumask);
-};
-
-int bL_cpufreq_register(const struct cpufreq_arm_bL_ops *ops);
-void bL_cpufreq_unregister(const struct cpufreq_arm_bL_ops *ops);
-
-#endif /* CPUFREQ_ARM_BIG_LITTLE_H */
diff --git a/drivers/cpufreq/vexpress-spc-cpufreq.c b/drivers/cpufreq/vexpress-spc-cpufreq.c
index 53237289e606..9d3f91832990 100644
--- a/drivers/cpufreq/vexpress-spc-cpufreq.c
+++ b/drivers/cpufreq/vexpress-spc-cpufreq.c
@@ -1,31 +1,661 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* Versatile Express SPC CPUFreq Interface driver
*
- * It provides necessary ops to arm_big_little cpufreq driver.
+ * Copyright (C) 2019 ARM Ltd.
+ * Sudeep Holla <sudeep.holla@xxxxxxx>
*
- * Copyright (C) 2013 ARM Ltd.
- * Sudeep KarkadaNagesha <sudeep.karkadanagesha@xxxxxxx>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed "as is" WITHOUT ANY WARRANTY of any
- * kind, whether express or implied; without even the implied warranty
- * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * Copyright (C) 2013 Linaro.
+ * Viresh Kumar <viresh.kumar@xxxxxxxxxx>
*/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

+#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
+#include <linux/cpumask.h>
+#include <linux/cpu_cooling.h>
+#include <linux/device.h>
+#include <linux/export.h>
#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_opp.h>
+#include <linux/slab.h>
+#include <linux/topology.h>
#include <linux/types.h>

-#include "arm_big_little.h"
+struct cpufreq_arm_bL_ops {
+ char name[CPUFREQ_NAME_LEN];
+
+ /*
+ * This must set opp table for cpu_dev in a similar way as done by
+ * dev_pm_opp_of_add_table().
+ */
+ int (*init_opp_table)(const struct cpumask *cpumask);
+
+ /* Optional */
+ int (*get_transition_latency)(struct device *cpu_dev);
+ void (*free_opp_table)(const struct cpumask *cpumask);
+};
+
+/* Currently we support only two clusters */
+#define A15_CLUSTER 0
+#define A7_CLUSTER 1
+#define MAX_CLUSTERS 2
+
+#ifdef CONFIG_BL_SWITCHER
+#include <asm/bL_switcher.h>
+static bool bL_switching_enabled;
+#define is_bL_switching_enabled() bL_switching_enabled
+#define set_switching_enabled(x) (bL_switching_enabled = (x))
+#else
+#define is_bL_switching_enabled() false
+#define set_switching_enabled(x) do { } while (0)
+#define bL_switch_request(...) do { } while (0)
+#define bL_switcher_put_enabled() do { } while (0)
+#define bL_switcher_get_enabled() do { } while (0)
+#endif
+
+#define ACTUAL_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq << 1 : freq)
+#define VIRT_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq >> 1 : freq)
+
+static struct thermal_cooling_device *cdev[MAX_CLUSTERS];
+static const struct cpufreq_arm_bL_ops *arm_bL_ops;
+static struct clk *clk[MAX_CLUSTERS];
+static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
+static atomic_t cluster_usage[MAX_CLUSTERS + 1];
+
+static unsigned int clk_big_min; /* (Big) clock frequencies */
+static unsigned int clk_little_max; /* Maximum clock frequency (Little) */
+
+static DEFINE_PER_CPU(unsigned int, physical_cluster);
+static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq);
+
+static struct mutex cluster_lock[MAX_CLUSTERS];
+
+static inline int raw_cpu_to_cluster(int cpu)
+{
+ return topology_physical_package_id(cpu);
+}
+
+static inline int cpu_to_cluster(int cpu)
+{
+ return is_bL_switching_enabled() ?
+ MAX_CLUSTERS : raw_cpu_to_cluster(cpu);
+}
+
+static unsigned int find_cluster_maxfreq(int cluster)
+{
+ int j;
+ u32 max_freq = 0, cpu_freq;
+
+ for_each_online_cpu(j) {
+ cpu_freq = per_cpu(cpu_last_req_freq, j);
+
+ if ((cluster == per_cpu(physical_cluster, j)) &&
+ (max_freq < cpu_freq))
+ max_freq = cpu_freq;
+ }
+
+ pr_debug("%s: cluster: %d, max freq: %d\n", __func__, cluster,
+ max_freq);
+
+ return max_freq;
+}
+
+static unsigned int clk_get_cpu_rate(unsigned int cpu)
+{
+ u32 cur_cluster = per_cpu(physical_cluster, cpu);
+ u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;
+
+ /* For switcher we use virtual A7 clock rates */
+ if (is_bL_switching_enabled())
+ rate = VIRT_FREQ(cur_cluster, rate);
+
+ pr_debug("%s: cpu: %d, cluster: %d, freq: %u\n", __func__, cpu,
+ cur_cluster, rate);
+
+ return rate;
+}
+
+static unsigned int bL_cpufreq_get_rate(unsigned int cpu)
+{
+ if (is_bL_switching_enabled()) {
+ pr_debug("%s: freq: %d\n", __func__, per_cpu(cpu_last_req_freq,
+ cpu));
+
+ return per_cpu(cpu_last_req_freq, cpu);
+ } else {
+ return clk_get_cpu_rate(cpu);
+ }
+}
+
+static unsigned int
+bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
+{
+ u32 new_rate, prev_rate;
+ int ret;
+ bool bLs = is_bL_switching_enabled();
+
+ mutex_lock(&cluster_lock[new_cluster]);
+
+ if (bLs) {
+ prev_rate = per_cpu(cpu_last_req_freq, cpu);
+ per_cpu(cpu_last_req_freq, cpu) = rate;
+ per_cpu(physical_cluster, cpu) = new_cluster;
+
+ new_rate = find_cluster_maxfreq(new_cluster);
+ new_rate = ACTUAL_FREQ(new_cluster, new_rate);
+ } else {
+ new_rate = rate;
+ }
+
+ pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n",
+ __func__, cpu, old_cluster, new_cluster, new_rate);
+
+ ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
+ if (!ret) {
+ /*
+ * FIXME: clk_set_rate hasn't returned an error here however it
+ * may be that clk_change_rate failed due to hardware or
+ * firmware issues and wasn't able to report that due to the
+ * current design of the clk core layer. To work around this
+ * problem we will read back the clock rate and check it is
+ * correct. This needs to be removed once clk core is fixed.
+ */
+ if (clk_get_rate(clk[new_cluster]) != new_rate * 1000)
+ ret = -EIO;
+ }
+
+ if (WARN_ON(ret)) {
+ pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
+ new_cluster);
+ if (bLs) {
+ per_cpu(cpu_last_req_freq, cpu) = prev_rate;
+ per_cpu(physical_cluster, cpu) = old_cluster;
+ }
+
+ mutex_unlock(&cluster_lock[new_cluster]);
+
+ return ret;
+ }
+
+ mutex_unlock(&cluster_lock[new_cluster]);
+
+ /* Recalc freq for old cluster when switching clusters */
+ if (old_cluster != new_cluster) {
+ pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n",
+ __func__, cpu, old_cluster, new_cluster);
+
+ /* Switch cluster */
+ bL_switch_request(cpu, new_cluster);
+
+ mutex_lock(&cluster_lock[old_cluster]);
+
+ /* Set freq of old cluster if there are cpus left on it */
+ new_rate = find_cluster_maxfreq(old_cluster);
+ new_rate = ACTUAL_FREQ(old_cluster, new_rate);
+
+ if (new_rate) {
+ pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
+ __func__, old_cluster, new_rate);
+
+ if (clk_set_rate(clk[old_cluster], new_rate * 1000))
+ pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
+ __func__, ret, old_cluster);
+ }
+ mutex_unlock(&cluster_lock[old_cluster]);
+ }
+
+ return 0;
+}
+
+/* Set clock frequency */
+static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
+ unsigned int index)
+{
+ u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
+ unsigned int freqs_new;
+ int ret;
+
+ cur_cluster = cpu_to_cluster(cpu);
+ new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
+
+ freqs_new = freq_table[cur_cluster][index].frequency;
+
+ if (is_bL_switching_enabled()) {
+ if ((actual_cluster == A15_CLUSTER) &&
+ (freqs_new < clk_big_min)) {
+ new_cluster = A7_CLUSTER;
+ } else if ((actual_cluster == A7_CLUSTER) &&
+ (freqs_new > clk_little_max)) {
+ new_cluster = A15_CLUSTER;
+ }
+ }
+
+ ret = bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
+
+ if (!ret) {
+ arch_set_freq_scale(policy->related_cpus, freqs_new,
+ policy->cpuinfo.max_freq);
+ }
+
+ return ret;
+}
+
+static inline u32 get_table_count(struct cpufreq_frequency_table *table)
+{
+ int count;
+
+ for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
+ ;
+
+ return count;
+}
+
+/* get the minimum frequency in the cpufreq_frequency_table */
+static inline u32 get_table_min(struct cpufreq_frequency_table *table)
+{
+ struct cpufreq_frequency_table *pos;
+ uint32_t min_freq = ~0;
+ cpufreq_for_each_entry(pos, table)
+ if (pos->frequency < min_freq)
+ min_freq = pos->frequency;
+ return min_freq;
+}
+
+/* get the maximum frequency in the cpufreq_frequency_table */
+static inline u32 get_table_max(struct cpufreq_frequency_table *table)
+{
+ struct cpufreq_frequency_table *pos;
+ uint32_t max_freq = 0;
+ cpufreq_for_each_entry(pos, table)
+ if (pos->frequency > max_freq)
+ max_freq = pos->frequency;
+ return max_freq;
+}
+
+static int merge_cluster_tables(void)
+{
+ int i, j, k = 0, count = 1;
+ struct cpufreq_frequency_table *table;
+
+ for (i = 0; i < MAX_CLUSTERS; i++)
+ count += get_table_count(freq_table[i]);
+
+ table = kcalloc(count, sizeof(*table), GFP_KERNEL);
+ if (!table)
+ return -ENOMEM;
+
+ freq_table[MAX_CLUSTERS] = table;
+
+ /* Add in reverse order to get freqs in increasing order */
+ for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
+ for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
+ j++) {
+ table[k].frequency = VIRT_FREQ(i,
+ freq_table[i][j].frequency);
+ pr_debug("%s: index: %d, freq: %d\n", __func__, k,
+ table[k].frequency);
+ k++;
+ }
+ }
+
+ table[k].driver_data = k;
+ table[k].frequency = CPUFREQ_TABLE_END;
+
+ pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
+
+ return 0;
+}
+
+static void _put_cluster_clk_and_freq_table(struct device *cpu_dev,
+ const struct cpumask *cpumask)
+{
+ u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
+
+ if (!freq_table[cluster])
+ return;
+
+ clk_put(clk[cluster]);
+ dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
+ if (arm_bL_ops->free_opp_table)
+ arm_bL_ops->free_opp_table(cpumask);
+ dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
+}
+
+static void put_cluster_clk_and_freq_table(struct device *cpu_dev,
+ const struct cpumask *cpumask)
+{
+ u32 cluster = cpu_to_cluster(cpu_dev->id);
+ int i;
+
+ if (atomic_dec_return(&cluster_usage[cluster]))
+ return;
+
+ if (cluster < MAX_CLUSTERS)
+ return _put_cluster_clk_and_freq_table(cpu_dev, cpumask);
+
+ for_each_present_cpu(i) {
+ struct device *cdev = get_cpu_device(i);
+ if (!cdev) {
+ pr_err("%s: failed to get cpu%d device\n", __func__, i);
+ return;
+ }
+
+ _put_cluster_clk_and_freq_table(cdev, cpumask);
+ }
+
+ /* free virtual table */
+ kfree(freq_table[cluster]);
+}
+
+static int _get_cluster_clk_and_freq_table(struct device *cpu_dev,
+ const struct cpumask *cpumask)
+{
+ u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
+ int ret;
+
+ if (freq_table[cluster])
+ return 0;
+
+ ret = arm_bL_ops->init_opp_table(cpumask);
+ if (ret) {
+ dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
+ __func__, cpu_dev->id, ret);
+ goto out;
+ }
+
+ ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
+ if (ret) {
+ dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
+ __func__, cpu_dev->id, ret);
+ goto free_opp_table;
+ }
+
+ clk[cluster] = clk_get(cpu_dev, NULL);
+ if (!IS_ERR(clk[cluster])) {
+ dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
+ __func__, clk[cluster], freq_table[cluster],
+ cluster);
+ return 0;
+ }
+
+ dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
+ __func__, cpu_dev->id, cluster);
+ ret = PTR_ERR(clk[cluster]);
+ dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
+
+free_opp_table:
+ if (arm_bL_ops->free_opp_table)
+ arm_bL_ops->free_opp_table(cpumask);
+out:
+ dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
+ cluster);
+ return ret;
+}
+
+static int get_cluster_clk_and_freq_table(struct device *cpu_dev,
+ const struct cpumask *cpumask)
+{
+ u32 cluster = cpu_to_cluster(cpu_dev->id);
+ int i, ret;
+
+ if (atomic_inc_return(&cluster_usage[cluster]) != 1)
+ return 0;
+
+ if (cluster < MAX_CLUSTERS) {
+ ret = _get_cluster_clk_and_freq_table(cpu_dev, cpumask);
+ if (ret)
+ atomic_dec(&cluster_usage[cluster]);
+ return ret;
+ }
+
+ /*
+ * Get data for all clusters and fill virtual cluster with a merge of
+ * both
+ */
+ for_each_present_cpu(i) {
+ struct device *cdev = get_cpu_device(i);
+ if (!cdev) {
+ pr_err("%s: failed to get cpu%d device\n", __func__, i);
+ return -ENODEV;
+ }
+
+ ret = _get_cluster_clk_and_freq_table(cdev, cpumask);
+ if (ret)
+ goto put_clusters;
+ }
+
+ ret = merge_cluster_tables();
+ if (ret)
+ goto put_clusters;
+
+ /* Assuming 2 cluster, set clk_big_min and clk_little_max */
+ clk_big_min = get_table_min(freq_table[0]);
+ clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
+
+ pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
+ __func__, cluster, clk_big_min, clk_little_max);
+
+ return 0;
+
+put_clusters:
+ for_each_present_cpu(i) {
+ struct device *cdev = get_cpu_device(i);
+ if (!cdev) {
+ pr_err("%s: failed to get cpu%d device\n", __func__, i);
+ return -ENODEV;
+ }
+
+ _put_cluster_clk_and_freq_table(cdev, cpumask);
+ }
+
+ atomic_dec(&cluster_usage[cluster]);
+
+ return ret;
+}
+
+/* Per-CPU initialization */
+static int bL_cpufreq_init(struct cpufreq_policy *policy)
+{
+ u32 cur_cluster = cpu_to_cluster(policy->cpu);
+ struct device *cpu_dev;
+ int ret;
+
+ 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;
+ }
+
+ if (cur_cluster < MAX_CLUSTERS) {
+ int cpu;
+
+ cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
+
+ for_each_cpu(cpu, policy->cpus)
+ per_cpu(physical_cluster, cpu) = cur_cluster;
+ } else {
+ /* Assumption: during init, we are always running on A15 */
+ per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
+ }
+
+ ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
+ if (ret)
+ return ret;
+
+ policy->freq_table = freq_table[cur_cluster];
+ policy->cpuinfo.transition_latency =
+ arm_bL_ops->get_transition_latency(cpu_dev);
+
+ dev_pm_opp_of_register_em(policy->cpus);
+
+ if (is_bL_switching_enabled())
+ per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);
+
+ dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
+ return 0;
+}
+
+static int bL_cpufreq_exit(struct cpufreq_policy *policy)
+{
+ struct device *cpu_dev;
+ int cur_cluster = cpu_to_cluster(policy->cpu);
+
+ if (cur_cluster < MAX_CLUSTERS) {
+ cpufreq_cooling_unregister(cdev[cur_cluster]);
+ cdev[cur_cluster] = NULL;
+ }
+
+ 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;
+ }
+
+ put_cluster_clk_and_freq_table(cpu_dev, policy->related_cpus);
+ dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
+
+ return 0;
+}
+
+static void bL_cpufreq_ready(struct cpufreq_policy *policy)
+{
+ int cur_cluster = cpu_to_cluster(policy->cpu);
+
+ /* Do not register a cpu_cooling device if we are in IKS mode */
+ if (cur_cluster >= MAX_CLUSTERS)
+ return;
+
+ cdev[cur_cluster] = of_cpufreq_cooling_register(policy);
+}
+
+static struct cpufreq_driver bL_cpufreq_driver = {
+ .name = "arm-big-little",
+ .flags = CPUFREQ_STICKY |
+ CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
+ CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+ .verify = cpufreq_generic_frequency_table_verify,
+ .target_index = bL_cpufreq_set_target,
+ .get = bL_cpufreq_get_rate,
+ .init = bL_cpufreq_init,
+ .exit = bL_cpufreq_exit,
+ .ready = bL_cpufreq_ready,
+ .attr = cpufreq_generic_attr,
+};
+
+#ifdef CONFIG_BL_SWITCHER
+static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
+ unsigned long action, void *_arg)
+{
+ pr_debug("%s: action: %ld\n", __func__, action);
+
+ switch (action) {
+ case BL_NOTIFY_PRE_ENABLE:
+ case BL_NOTIFY_PRE_DISABLE:
+ cpufreq_unregister_driver(&bL_cpufreq_driver);
+ break;
+
+ case BL_NOTIFY_POST_ENABLE:
+ set_switching_enabled(true);
+ cpufreq_register_driver(&bL_cpufreq_driver);
+ break;
+
+ case BL_NOTIFY_POST_DISABLE:
+ set_switching_enabled(false);
+ cpufreq_register_driver(&bL_cpufreq_driver);
+ break;
+
+ default:
+ return NOTIFY_DONE;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block bL_switcher_notifier = {
+ .notifier_call = bL_cpufreq_switcher_notifier,
+};
+
+static int __bLs_register_notifier(void)
+{
+ return bL_switcher_register_notifier(&bL_switcher_notifier);
+}
+
+static int __bLs_unregister_notifier(void)
+{
+ return bL_switcher_unregister_notifier(&bL_switcher_notifier);
+}
+#else
+static int __bLs_register_notifier(void) { return 0; }
+static int __bLs_unregister_notifier(void) { return 0; }
+#endif
+
+int bL_cpufreq_register(const struct cpufreq_arm_bL_ops *ops)
+{
+ int ret, i;
+
+ if (arm_bL_ops) {
+ pr_debug("%s: Already registered: %s, exiting\n", __func__,
+ arm_bL_ops->name);
+ return -EBUSY;
+ }
+
+ if (!ops || !strlen(ops->name) || !ops->init_opp_table ||
+ !ops->get_transition_latency) {
+ pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
+ return -ENODEV;
+ }
+
+ arm_bL_ops = ops;
+
+ set_switching_enabled(bL_switcher_get_enabled());
+
+ for (i = 0; i < MAX_CLUSTERS; i++)
+ mutex_init(&cluster_lock[i]);
+
+ ret = cpufreq_register_driver(&bL_cpufreq_driver);
+ if (ret) {
+ pr_info("%s: Failed registering platform driver: %s, err: %d\n",
+ __func__, ops->name, ret);
+ arm_bL_ops = NULL;
+ } else {
+ ret = __bLs_register_notifier();
+ if (ret) {
+ cpufreq_unregister_driver(&bL_cpufreq_driver);
+ arm_bL_ops = NULL;
+ } else {
+ pr_info("%s: Registered platform driver: %s\n",
+ __func__, ops->name);
+ }
+ }
+
+ bL_switcher_put_enabled();
+ return ret;
+}
+
+void bL_cpufreq_unregister(const struct cpufreq_arm_bL_ops *ops)
+{
+ if (arm_bL_ops != ops) {
+ pr_err("%s: Registered with: %s, can't unregister, exiting\n",
+ __func__, arm_bL_ops->name);
+ return;
+ }
+
+ bL_switcher_get_enabled();
+ __bLs_unregister_notifier();
+ cpufreq_unregister_driver(&bL_cpufreq_driver);
+ bL_switcher_put_enabled();
+ pr_info("%s: Un-registered platform driver: %s\n", __func__,
+ arm_bL_ops->name);
+ arm_bL_ops = NULL;
+}

static int ve_spc_init_opp_table(const struct cpumask *cpumask)
{
@@ -68,4 +698,7 @@ static struct platform_driver ve_spc_cpufreq_platdrv = {
};
module_platform_driver(ve_spc_cpufreq_platdrv);

-MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Viresh Kumar <viresh.kumar@xxxxxxxxxx>");
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@xxxxxxx>");
+MODULE_DESCRIPTION("Vexpress SPC ARM big LITTLE cpufreq driver");
+MODULE_LICENSE("GPL v2");
--
2.17.1