File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/arm/mach-imx/mmdc.c b/arch/arm/mach-imx/mmdc.c
new file mode 100644
index 0000000..db9621c
--- /dev/null
+++ b/arch/arm/mach-imx/mmdc.c
@@ -0,0 +1,90 @@
+/*
+ * 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>
+
+#include "common.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);