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Subject[PATCH 1/2] ARM: topology: Use a clock if possible to get the CPU frequency
Date
The Cortex-A7 and Cortex-A15 based SoCs need a clock-frequency property in the
topology code.

Allow to use a clock to provide the same information.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
arch/arm/kernel/topology.c | 24 +++++++++++++++++-------
1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index 0bc94b1fd1ae..2885993ccf53 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -11,6 +11,7 @@
* for more details.
*/

+#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <linux/export.h>
@@ -100,8 +101,8 @@ static void __init parse_dt_topology(void)
__cpu_capacity = kzalloc(alloc_size, GFP_NOWAIT);

for_each_possible_cpu(cpu) {
- const u32 *rate;
- int len;
+ struct clk *clk;
+ u32 rate = 0;

/* too early to use cpu->of_node */
cn = of_get_cpu_node(cpu, NULL);
@@ -117,14 +118,23 @@ static void __init parse_dt_topology(void)
if (cpu_eff->compatible == NULL)
continue;

- rate = of_get_property(cn, "clock-frequency", &len);
- if (!rate || len != 4) {
- pr_err("%s missing clock-frequency property\n",
- cn->full_name);
+ clk = of_clk_get(cn, 0);
+ if (!IS_ERR(clk)) {
+ rate = clk_get_rate(clk);
+ } else {
+ if (of_property_read_u32(cn, "clock-frequency", &rate)) {
+ pr_err("%s missing clocks or clock-frequency properties\n",
+ cn->full_name);
+ continue;
+ }
+ }
+
+ if (!rate) {
+ pr_err("%s invalid CPU frequency", cn->full_name);
continue;
}

- capacity = ((be32_to_cpup(rate)) >> 20) * cpu_eff->efficiency;
+ capacity = ((rate) >> 20) * cpu_eff->efficiency;

/* Save min capacity of the system */
if (capacity < min_capacity)
--
1.9.3


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