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path: root/drivers/cpuidle/cpuidle-kirkwood.c
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Diffstat (limited to 'drivers/cpuidle/cpuidle-kirkwood.c')
-rw-r--r--drivers/cpuidle/cpuidle-kirkwood.c87
1 files changed, 87 insertions, 0 deletions
diff --git a/drivers/cpuidle/cpuidle-kirkwood.c b/drivers/cpuidle/cpuidle-kirkwood.c
new file mode 100644
index 000000000..d23d8f468
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-kirkwood.c
@@ -0,0 +1,87 @@
+/*
+ * CPU idle Marvell Kirkwood SoCs
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * The cpu idle uses wait-for-interrupt and DDR self refresh in order
+ * to implement two idle states -
+ * #1 wait-for-interrupt
+ * #2 wait-for-interrupt and DDR self refresh
+ *
+ * Maintainer: Jason Cooper <jason@lakedaemon.net>
+ * Maintainer: Andrew Lunn <andrew@lunn.ch>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.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 KIRKWOOD_MAX_STATES 2
+
+static void __iomem *ddr_operation_base;
+
+/* Actual code that puts the SoC in different idle states */
+static int kirkwood_enter_idle(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ writel(0x7, ddr_operation_base);
+ cpu_do_idle();
+
+ return index;
+}
+
+static struct cpuidle_driver kirkwood_idle_driver = {
+ .name = "kirkwood_idle",
+ .owner = THIS_MODULE,
+ .states[0] = ARM_CPUIDLE_WFI_STATE,
+ .states[1] = {
+ .enter = kirkwood_enter_idle,
+ .exit_latency = 10,
+ .target_residency = 100000,
+ .name = "DDR SR",
+ .desc = "WFI and DDR Self Refresh",
+ },
+ .state_count = KIRKWOOD_MAX_STATES,
+};
+
+/* Initialize CPU idle by registering the idle states */
+static int kirkwood_cpuidle_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ ddr_operation_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(ddr_operation_base))
+ return PTR_ERR(ddr_operation_base);
+
+ return cpuidle_register(&kirkwood_idle_driver, NULL);
+}
+
+static int kirkwood_cpuidle_remove(struct platform_device *pdev)
+{
+ cpuidle_unregister(&kirkwood_idle_driver);
+ return 0;
+}
+
+static struct platform_driver kirkwood_cpuidle_driver = {
+ .probe = kirkwood_cpuidle_probe,
+ .remove = kirkwood_cpuidle_remove,
+ .driver = {
+ .name = "kirkwood_cpuidle",
+ },
+};
+
+module_platform_driver(kirkwood_cpuidle_driver);
+
+MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
+MODULE_DESCRIPTION("Kirkwood cpu idle driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:kirkwood-cpuidle");