In the previous code, cpufreq-dt driver support single clock shared by
all CPUs or every CPU has dedicated clock; but it cannot support cluster
level clock domain, which is very common implementation for ARM SoCs.
So this patch add the support for cluster level clock; which use the
platform parameter "clk_domain_boundary" to indicate whether the clock
domain is bound to system level, cluster level or CPU level.
Signed-off-by: Leo Yan <leo....@linaro.org>
---
drivers/cpufreq/Kconfig | 5 +++--
drivers/cpufreq/cpufreq-dt.c | 14 +++++++++++++-
include/linux/cpufreq-dt.h | 16 ++++++++++++----
3 files changed, 28 insertions(+), 7 deletions(-)
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index a171fef..fe1aee1 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -193,8 +193,9 @@ config CPUFREQ_DT
select PM_OPP
help
This adds a generic DT based cpufreq driver for frequency management.
- It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
- systems which share clock and voltage across all CPUs.
+ It supports uniprocessor (UP), and symmetric multiprocessor (SMP)
+ systems which share clock and voltage across all CPUs; and it also
+ supports cluster level or cpu level's clock domain.
If in doubt, say N.
diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
index bab67db..c03532c 100644
--- a/drivers/cpufreq/cpufreq-dt.c
+++ b/drivers/cpufreq/cpufreq-dt.c
@@ -294,8 +294,20 @@ static int cpufreq_init(struct cpufreq_policy *policy)
policy->cpuinfo.transition_latency = transition_latency;
pd = cpufreq_get_driver_data();
- if (!pd || !pd->independent_clocks)
+ if (!pd || pd->clk_domain_boundary == CPUFREQ_DT_CLK_PER_SYS)
cpumask_setall(policy->cpus);
+ else if (pd->clk_domain_boundary == CPUFREQ_DT_CLK_PER_CLUSTER)
+ cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
+ else if (pd->clk_domain_boundary != CPUFREQ_DT_CLK_PER_CPU) {
+ /*
+ * If each CPU has its own clock, don't need bind cpus;
+ * otherwise will handle wrong parameter.
+ */
+ dev_err(cpu_dev, "%s: invalid clk boundary value: %d\n",
+ __func__, pd->clk_domain_boundary);
+ ret = -EINVAL;
+ goto out_free_cpufreq_table;
+ }
of_node_put(np);
diff --git a/include/linux/cpufreq-dt.h b/include/linux/cpufreq-dt.h
index 0414009..d6fe6e3 100644
--- a/include/linux/cpufreq-dt.h
+++ b/include/linux/cpufreq-dt.h
@@ -10,13 +10,21 @@
#ifndef __CPUFREQ_DT_H__
#define __CPUFREQ_DT_H__
+enum cpufreq_dt_clk_type {
+ CPUFREQ_DT_CLK_PER_SYS = 0,
+ CPUFREQ_DT_CLK_PER_CLUSTER,
+ CPUFREQ_DT_CLK_PER_CPU,
+};
+
struct cpufreq_dt_platform_data {
/*
- * True when each CPU has its own clock to control its
- * frequency, false when all CPUs are controlled by a single
- * clock.
+ * Use this to distinguish three kinds of clock domain:
+ *
+ * - all CPUs are controlled by a single clock;
+ * - all CPUs in cluster share one clock;
+ * - each CPU has its own clock to control its frequency;
*/
- bool independent_clocks;
+ enum cpufreq_dt_clk_type clk_domain_boundary;
};
#endif /* __CPUFREQ_DT_H__ */
--
1.9.1
--
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