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9fbbe689 SG |
1 | /* |
2 | * Copyright 2011 Freescale Semiconductor, Inc. | |
3 | * Copyright 2011 Linaro Ltd. | |
4 | * | |
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: | |
8 | * | |
9 | * http://www.opensource.org/licenses/gpl-license.html | |
10 | * http://www.gnu.org/copyleft/gpl.html | |
11 | */ | |
12 | ||
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> | |
19 | ||
20 | #define MMDC_MAPSR 0x404 | |
21 | #define BP_MMDC_MAPSR_PSD 0 | |
22 | #define BP_MMDC_MAPSR_PSS 4 | |
23 | ||
351a102d | 24 | static int imx_mmdc_probe(struct platform_device *pdev) |
9fbbe689 SG |
25 | { |
26 | struct device_node *np = pdev->dev.of_node; | |
27 | void __iomem *mmdc_base, *reg; | |
28 | u32 val; | |
29 | int timeout = 0x400; | |
30 | ||
31 | mmdc_base = of_iomap(np, 0); | |
32 | WARN_ON(!mmdc_base); | |
33 | ||
34 | reg = mmdc_base + MMDC_MAPSR; | |
35 | ||
36 | /* Enable automatic power saving */ | |
37 | val = readl_relaxed(reg); | |
38 | val &= ~(1 << BP_MMDC_MAPSR_PSD); | |
39 | writel_relaxed(val, reg); | |
40 | ||
41 | /* Ensure it's successfully enabled */ | |
42 | while (!(readl_relaxed(reg) & 1 << BP_MMDC_MAPSR_PSS) && --timeout) | |
43 | cpu_relax(); | |
44 | ||
45 | if (unlikely(!timeout)) { | |
46 | pr_warn("%s: failed to enable automatic power saving\n", | |
47 | __func__); | |
48 | return -EBUSY; | |
49 | } | |
50 | ||
51 | return 0; | |
52 | } | |
53 | ||
54 | static struct of_device_id imx_mmdc_dt_ids[] = { | |
55 | { .compatible = "fsl,imx6q-mmdc", }, | |
56 | { /* sentinel */ } | |
57 | }; | |
58 | ||
59 | static struct platform_driver imx_mmdc_driver = { | |
60 | .driver = { | |
61 | .name = "imx-mmdc", | |
62 | .owner = THIS_MODULE, | |
63 | .of_match_table = imx_mmdc_dt_ids, | |
64 | }, | |
65 | .probe = imx_mmdc_probe, | |
66 | }; | |
67 | ||
68 | static int __init imx_mmdc_init(void) | |
69 | { | |
70 | return platform_driver_register(&imx_mmdc_driver); | |
71 | } | |
72 | postcore_initcall(imx_mmdc_init); |