91 lines
2.0 KiB
C
91 lines
2.0 KiB
C
/*
|
|
* 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);
|