1 files changed, 62 insertions, 0 deletions
diff --git a/drivers/cpuidle/cpuidle-at91.c b/drivers/cpuidle/cpuidle-at91.c
new file mode 100644
index 000000000..45ee8e1e7
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-at91.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * based on arch/arm/mach-kirkwood/cpuidle.c
+ *
+ * CPU idle support for AT91 SoC
+ *
+ * The cpu idle uses wait-for-interrupt and RAM self refresh in order
+ * to implement two idle states -
+ * #1 wait-for-interrupt
+ * #2 wait-for-interrupt and RAM self refresh
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/cpuidle.h>
+#include <linux/io.h>
+#include <linux/export.h>
+#include <asm/cpuidle.h>
+
+#define AT91_MAX_STATES	2
+
+static void (*at91_standby)(void);
+
+/* Actual code that puts the SoC in different idle states */
+static int at91_enter_idle(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv,
+			       int index)
+{
+	at91_standby();
+	return index;
+}
+
+static struct cpuidle_driver at91_idle_driver = {
+	.name			= "at91_idle",
+	.owner			= THIS_MODULE,
+	.states[0]		= ARM_CPUIDLE_WFI_STATE,
+	.states[1]		= {
+		.enter			= at91_enter_idle,
+		.exit_latency		= 10,
+		.target_residency	= 10000,
+		.name			= "RAM_SR",
+		.desc			= "WFI and DDR Self Refresh",
+	},
+	.state_count = AT91_MAX_STATES,
+};
+
+/* Initialize CPU idle by registering the idle states */
+static int at91_cpuidle_probe(struct platform_device *dev)
+{
+	at91_standby = (void *)(dev->dev.platform_data);
+	
+	return cpuidle_register(&at91_idle_driver, NULL);
+}
+
+static struct platform_driver at91_cpuidle_driver = {
+	.driver = {
+		.name = "cpuidle-at91",
+	},
+	.probe = at91_cpuidle_probe,
+};
+builtin_platform_driver(at91_cpuidle_driver);