1 files changed, 99 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/cpuidle.c b/arch/arm/mach-davinci/cpuidle.c
new file mode 100644
index 0000000000..78a1575c38
--- /dev/null
+++ b/arch/arm/mach-davinci/cpuidle.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * CPU idle for DaVinci SoCs
+ *
+ * Copyright (C) 2009 Texas Instruments Incorporated. https://www.ti.com/
+ *
+ * Derived from Marvell Kirkwood CPU idle code
+ * (arch/arm/mach-kirkwood/cpuidle.c)
+ */
+
+#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>
+
+#include "cpuidle.h"
+#include "ddr2.h"
+
+#define DAVINCI_CPUIDLE_MAX_STATES	2
+
+static void __iomem *ddr2_reg_base;
+static bool ddr2_pdown;
+
+static void davinci_save_ddr_power(int enter, bool pdown)
+{
+	u32 val;
+
+	val = __raw_readl(ddr2_reg_base + DDR2_SDRCR_OFFSET);
+
+	if (enter) {
+		if (pdown)
+			val |= DDR2_SRPD_BIT;
+		else
+			val &= ~DDR2_SRPD_BIT;
+		val |= DDR2_LPMODEN_BIT;
+	} else {
+		val &= ~(DDR2_SRPD_BIT | DDR2_LPMODEN_BIT);
+	}
+
+	__raw_writel(val, ddr2_reg_base + DDR2_SDRCR_OFFSET);
+}
+
+/* Actual code that puts the SoC in different idle states */
+static __cpuidle int davinci_enter_idle(struct cpuidle_device *dev,
+					struct cpuidle_driver *drv, int index)
+{
+	davinci_save_ddr_power(1, ddr2_pdown);
+	cpu_do_idle();
+	davinci_save_ddr_power(0, ddr2_pdown);
+
+	return index;
+}
+
+static struct cpuidle_driver davinci_idle_driver = {
+	.name			= "cpuidle-davinci",
+	.owner			= THIS_MODULE,
+	.states[0]		= ARM_CPUIDLE_WFI_STATE,
+	.states[1]		= {
+		.enter			= davinci_enter_idle,
+		.exit_latency		= 10,
+		.target_residency	= 10000,
+		.name			= "DDR SR",
+		.desc			= "WFI and DDR Self Refresh",
+	},
+	.state_count = DAVINCI_CPUIDLE_MAX_STATES,
+};
+
+static int __init davinci_cpuidle_probe(struct platform_device *pdev)
+{
+	struct davinci_cpuidle_config *pdata = pdev->dev.platform_data;
+
+	if (!pdata) {
+		dev_err(&pdev->dev, "cannot get platform data\n");
+		return -ENOENT;
+	}
+
+	ddr2_reg_base = pdata->ddr2_ctlr_base;
+
+	ddr2_pdown = pdata->ddr2_pdown;
+
+	return cpuidle_register(&davinci_idle_driver, NULL);
+}
+
+static struct platform_driver davinci_cpuidle_driver = {
+	.driver = {
+		.name	= "cpuidle-davinci",
+	},
+};
+
+static int __init davinci_cpuidle_init(void)
+{
+	return platform_driver_probe(&davinci_cpuidle_driver,
+						davinci_cpuidle_probe);
+}
+device_initcall(davinci_cpuidle_init);
+