| /* |
| * 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); |