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authorDaniel Lezcano <daniel.lezcano@linaro.org>2015-02-02 16:32:45 +0100
committerDaniel Lezcano <daniel.lezcano@linaro.org>2015-03-24 10:16:01 +0100
commit449e056c76cc8c777f3f5c3fb51c197ba2300c0c (patch)
treedb3091b6320f46a860cd048a0978d4002837edf6 /arch/arm/kernel
parenteeebc3bb4d5d7edb56cb594e8f0ec2cfb10c2518 (diff)
ARM: cpuidle: Add a cpuidle ops structure to be used for DT
The current state of the different cpuidle drivers is the different PM operations are passed via the platform_data using the platform driver paradigm. This approach allowed to split the low level PM code from the arch specific and the generic cpuidle code. Unfortunately there are complaints about this approach as, in the context of the single kernel image, we have multiple drivers loaded in memory for nothing and the platform driver is not adequate for cpuidle. This patch provides a common interface via cpuidle ops for all new cpuidle driver and a definition for the device tree. It will allow with the next patches to a have a common definition with ARM64 and share the same cpuidle driver. The code is optimized to use the __init section intensively in order to reduce the memory footprint after the driver is initialized and unify the function names with ARM64. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Kevin Hilman <khilman@linaro.org> Acked-by: Rob Herring <robherring2@gmail.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/cpuidle.c72
1 files changed, 72 insertions, 0 deletions
diff --git a/arch/arm/kernel/cpuidle.c b/arch/arm/kernel/cpuidle.c
index 45969f89f05c..2b0dae3cd058 100644
--- a/arch/arm/kernel/cpuidle.c
+++ b/arch/arm/kernel/cpuidle.c
@@ -10,8 +10,17 @@
*/
#include <linux/cpuidle.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
#include <asm/cpuidle.h>
+extern struct of_cpuidle_method __cpuidle_method_of_table[];
+
+static const struct of_cpuidle_method __cpuidle_method_of_table_sentinel
+ __used __section(__cpuidle_method_of_table_end);
+
+static struct cpuidle_ops cpuidle_ops[NR_CPUS];
+
int arm_cpuidle_simple_enter(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index)
{
@@ -19,3 +28,66 @@ int arm_cpuidle_simple_enter(struct cpuidle_device *dev,
return index;
}
+
+int arm_cpuidle_suspend(int index)
+{
+ int ret = -EOPNOTSUPP;
+ int cpu = smp_processor_id();
+
+ if (cpuidle_ops[cpu].suspend)
+ ret = cpuidle_ops[cpu].suspend(cpu, index);
+
+ return ret;
+}
+
+static struct cpuidle_ops *__init arm_cpuidle_get_ops(const char *method)
+{
+ struct of_cpuidle_method *m = __cpuidle_method_of_table;
+
+ for (; m->method; m++)
+ if (!strcmp(m->method, method))
+ return m->ops;
+
+ return NULL;
+}
+
+static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
+{
+ const char *enable_method;
+ struct cpuidle_ops *ops;
+
+ enable_method = of_get_property(dn, "enable-method", NULL);
+ if (!enable_method)
+ return -ENOENT;
+
+ ops = arm_cpuidle_get_ops(enable_method);
+ if (!ops) {
+ pr_warn("%s: unsupported enable-method property: %s\n",
+ dn->full_name, enable_method);
+ return -EOPNOTSUPP;
+ }
+
+ cpuidle_ops[cpu] = *ops; /* structure copy */
+
+ pr_notice("cpuidle: enable-method property '%s'"
+ " found operations\n", enable_method);
+
+ return 0;
+}
+
+int __init arm_cpuidle_init(int cpu)
+{
+ struct device_node *cpu_node = of_cpu_device_node_get(cpu);
+ int ret;
+
+ if (!cpu_node)
+ return -ENODEV;
+
+ ret = arm_cpuidle_read_ops(cpu_node, cpu);
+ if (!ret && cpuidle_ops[cpu].init)
+ ret = cpuidle_ops[cpu].init(cpu_node, cpu);
+
+ of_node_put(cpu_node);
+
+ return ret;
+}