blk: rq_data_dir() should not return a boolean
[cris-mirror.git] / arch / arm / mach-imx / mmdc.c
blobdb9621c718ecae1ff2567f596f4d71ecd6428c4a
1 /*
2 * Copyright 2011 Freescale Semiconductor, Inc.
3 * Copyright 2011 Linaro Ltd.
5 * The code contained herein is licensed under the GNU General Public
6 * License. You may obtain a copy of the GNU General Public License
7 * Version 2 or later at the following locations:
9 * http://www.opensource.org/licenses/gpl-license.html
10 * http://www.gnu.org/copyleft/gpl.html
13 #include <linux/init.h>
14 #include <linux/io.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/of_address.h>
18 #include <linux/of_device.h>
20 #include "common.h"
22 #define MMDC_MAPSR 0x404
23 #define BP_MMDC_MAPSR_PSD 0
24 #define BP_MMDC_MAPSR_PSS 4
26 #define MMDC_MDMISC 0x18
27 #define BM_MMDC_MDMISC_DDR_TYPE 0x18
28 #define BP_MMDC_MDMISC_DDR_TYPE 0x3
30 static int ddr_type;
32 static int imx_mmdc_probe(struct platform_device *pdev)
34 struct device_node *np = pdev->dev.of_node;
35 void __iomem *mmdc_base, *reg;
36 u32 val;
37 int timeout = 0x400;
39 mmdc_base = of_iomap(np, 0);
40 WARN_ON(!mmdc_base);
42 reg = mmdc_base + MMDC_MDMISC;
43 /* Get ddr type */
44 val = readl_relaxed(reg);
45 ddr_type = (val & BM_MMDC_MDMISC_DDR_TYPE) >>
46 BP_MMDC_MDMISC_DDR_TYPE;
48 reg = mmdc_base + MMDC_MAPSR;
50 /* Enable automatic power saving */
51 val = readl_relaxed(reg);
52 val &= ~(1 << BP_MMDC_MAPSR_PSD);
53 writel_relaxed(val, reg);
55 /* Ensure it's successfully enabled */
56 while (!(readl_relaxed(reg) & 1 << BP_MMDC_MAPSR_PSS) && --timeout)
57 cpu_relax();
59 if (unlikely(!timeout)) {
60 pr_warn("%s: failed to enable automatic power saving\n",
61 __func__);
62 return -EBUSY;
65 return 0;
68 int imx_mmdc_get_ddr_type(void)
70 return ddr_type;
73 static const struct of_device_id imx_mmdc_dt_ids[] = {
74 { .compatible = "fsl,imx6q-mmdc", },
75 { /* sentinel */ }
78 static struct platform_driver imx_mmdc_driver = {
79 .driver = {
80 .name = "imx-mmdc",
81 .of_match_table = imx_mmdc_dt_ids,
83 .probe = imx_mmdc_probe,
86 static int __init imx_mmdc_init(void)
88 return platform_driver_register(&imx_mmdc_driver);
90 postcore_initcall(imx_mmdc_init);