1 files changed, 88 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-imx/mmdc.c b/kernel/arch/arm/mach-imx/mmdc.c
new file mode 100644
index 000000000..0411f0664
--- /dev/null
+++ b/kernel/arch/arm/mach-imx/mmdc.c
@@ -0,0 +1,88 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ * Copyright 2011 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+
+#define MMDC_MAPSR		0x404
+#define BP_MMDC_MAPSR_PSD	0
+#define BP_MMDC_MAPSR_PSS	4
+
+#define MMDC_MDMISC		0x18
+#define BM_MMDC_MDMISC_DDR_TYPE	0x18
+#define BP_MMDC_MDMISC_DDR_TYPE	0x3
+
+static int ddr_type;
+
+static int imx_mmdc_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	void __iomem *mmdc_base, *reg;
+	u32 val;
+	int timeout = 0x400;
+
+	mmdc_base = of_iomap(np, 0);
+	WARN_ON(!mmdc_base);
+
+	reg = mmdc_base + MMDC_MDMISC;
+	/* Get ddr type */
+	val = readl_relaxed(reg);
+	ddr_type = (val & BM_MMDC_MDMISC_DDR_TYPE) >>
+		 BP_MMDC_MDMISC_DDR_TYPE;
+
+	reg = mmdc_base + MMDC_MAPSR;
+
+	/* Enable automatic power saving */
+	val = readl_relaxed(reg);
+	val &= ~(1 << BP_MMDC_MAPSR_PSD);
+	writel_relaxed(val, reg);
+
+	/* Ensure it's successfully enabled */
+	while (!(readl_relaxed(reg) & 1 << BP_MMDC_MAPSR_PSS) && --timeout)
+		cpu_relax();
+
+	if (unlikely(!timeout)) {
+		pr_warn("%s: failed to enable automatic power saving\n",
+			__func__);
+		return -EBUSY;
+	}
+
+	return 0;
+}
+
+int imx_mmdc_get_ddr_type(void)
+{
+	return ddr_type;
+}
+
+static const struct of_device_id imx_mmdc_dt_ids[] = {
+	{ .compatible = "fsl,imx6q-mmdc", },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver imx_mmdc_driver = {
+	.driver		= {
+		.name	= "imx-mmdc",
+		.of_match_table = imx_mmdc_dt_ids,
+	},
+	.probe		= imx_mmdc_probe,
+};
+
+static int __init imx_mmdc_init(void)
+{
+	return platform_driver_register(&imx_mmdc_driver);
+}
+postcore_initcall(imx_mmdc_init);