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authorShawn Guo <shawn.guo@linaro.org>2011-09-06 14:39:44 +0800
committerArnd Bergmann <arnd@arndb.de>2011-10-31 14:26:23 +0100
commit9fbbe6890c88aa332efe61d5894108dd8b932530 (patch)
treeb27bedc317d68e969e9220cb93de8bc9fc5c62e8 /arch/arm/mach-imx/mmdc.c
parent1103643c266ae45c7098e0f7f3ee0b68e3e7c7cc (diff)
arm/imx6q: add core drivers clock, gpc, mmdc and src
It adds a number of core drivers support for imx6q, including clock, General Power Controller (gpc), Multi Mode DDR Controller(mmdc) and System Reset Controller (src). Signed-off-by: Ranjani Vaidyanathan <ra5478@freescale.com> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Diffstat (limited to 'arch/arm/mach-imx/mmdc.c')
-rw-r--r--arch/arm/mach-imx/mmdc.c72
1 files changed, 72 insertions, 0 deletions
diff --git a/arch/arm/mach-imx/mmdc.c b/arch/arm/mach-imx/mmdc.c
new file mode 100644
index 000000000000..c461e98496c3
--- /dev/null
+++ b/arch/arm/mach-imx/mmdc.c
@@ -0,0 +1,72 @@
+/*
+ * 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
+
+static int __devinit 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_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;
+}
+
+static struct of_device_id imx_mmdc_dt_ids[] = {
+ { .compatible = "fsl,imx6q-mmdc", },
+ { /* sentinel */ }
+};
+
+static struct platform_driver imx_mmdc_driver = {
+ .driver = {
+ .name = "imx-mmdc",
+ .owner = THIS_MODULE,
+ .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);