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85bf6d4e HS |
1 | /* |
2 | * EIM driver for Freescale's i.MX chips | |
3 | * | |
4 | * Copyright (C) 2013 Freescale Semiconductor, Inc. | |
5 | * | |
6 | * This file is licensed under the terms of the GNU General Public | |
7 | * License version 2. This program is licensed "as is" without any | |
8 | * warranty of any kind, whether express or implied. | |
9 | */ | |
10 | #include <linux/module.h> | |
11 | #include <linux/clk.h> | |
12 | #include <linux/io.h> | |
13 | #include <linux/of_device.h> | |
14 | ||
15 | struct imx_weim { | |
16 | void __iomem *base; | |
17 | struct clk *clk; | |
18 | }; | |
19 | ||
20 | static const struct of_device_id weim_id_table[] = { | |
21 | { .compatible = "fsl,imx6q-weim", }, | |
22 | {} | |
23 | }; | |
24 | MODULE_DEVICE_TABLE(of, weim_id_table); | |
25 | ||
26 | #define CS_TIMING_LEN 6 | |
27 | #define CS_REG_RANGE 0x18 | |
28 | ||
29 | /* Parse and set the timing for this device. */ | |
30 | static int | |
31 | weim_timing_setup(struct platform_device *pdev, struct device_node *np) | |
32 | { | |
33 | struct imx_weim *weim = platform_get_drvdata(pdev); | |
34 | u32 value[CS_TIMING_LEN]; | |
35 | u32 cs_idx; | |
36 | int ret; | |
37 | int i; | |
38 | ||
39 | /* get the CS index from this child node's "reg" property. */ | |
40 | ret = of_property_read_u32(np, "reg", &cs_idx); | |
41 | if (ret) | |
42 | return ret; | |
43 | ||
44 | /* The weim has four chip selects. */ | |
45 | if (cs_idx > 3) | |
46 | return -EINVAL; | |
47 | ||
48 | ret = of_property_read_u32_array(np, "fsl,weim-cs-timing", | |
49 | value, CS_TIMING_LEN); | |
50 | if (ret) | |
51 | return ret; | |
52 | ||
53 | /* set the timing for WEIM */ | |
54 | for (i = 0; i < CS_TIMING_LEN; i++) | |
55 | writel(value[i], weim->base + cs_idx * CS_REG_RANGE + i * 4); | |
56 | return 0; | |
57 | } | |
58 | ||
59 | static int weim_parse_dt(struct platform_device *pdev) | |
60 | { | |
61 | struct device_node *child; | |
62 | int ret; | |
63 | ||
64 | for_each_child_of_node(pdev->dev.of_node, child) { | |
65 | if (!child->name) | |
66 | continue; | |
67 | ||
68 | ret = weim_timing_setup(pdev, child); | |
69 | if (ret) { | |
70 | dev_err(&pdev->dev, "%s set timing failed.\n", | |
71 | child->full_name); | |
72 | return ret; | |
73 | } | |
74 | } | |
75 | ||
76 | ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev); | |
77 | if (ret) | |
78 | dev_err(&pdev->dev, "%s fail to create devices.\n", | |
79 | pdev->dev.of_node->full_name); | |
80 | return ret; | |
81 | } | |
82 | ||
83 | static int weim_probe(struct platform_device *pdev) | |
84 | { | |
85 | struct imx_weim *weim; | |
86 | struct resource *res; | |
87 | int ret = -EINVAL; | |
88 | ||
89 | weim = devm_kzalloc(&pdev->dev, sizeof(*weim), GFP_KERNEL); | |
90 | if (!weim) { | |
91 | ret = -ENOMEM; | |
92 | goto weim_err; | |
93 | } | |
94 | platform_set_drvdata(pdev, weim); | |
95 | ||
96 | /* get the resource */ | |
97 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
98 | weim->base = devm_ioremap_resource(&pdev->dev, res); | |
99 | if (IS_ERR(weim->base)) { | |
100 | ret = PTR_ERR(weim->base); | |
101 | goto weim_err; | |
102 | } | |
103 | ||
104 | /* get the clock */ | |
105 | weim->clk = devm_clk_get(&pdev->dev, NULL); | |
106 | if (IS_ERR(weim->clk)) | |
107 | goto weim_err; | |
108 | ||
109 | ret = clk_prepare_enable(weim->clk); | |
110 | if (ret) | |
111 | goto weim_err; | |
112 | ||
113 | /* parse the device node */ | |
114 | ret = weim_parse_dt(pdev); | |
115 | if (ret) { | |
116 | clk_disable_unprepare(weim->clk); | |
117 | goto weim_err; | |
118 | } | |
119 | ||
120 | dev_info(&pdev->dev, "WEIM driver registered.\n"); | |
121 | return 0; | |
122 | ||
123 | weim_err: | |
124 | return ret; | |
125 | } | |
126 | ||
127 | static struct platform_driver weim_driver = { | |
128 | .driver = { | |
129 | .name = "imx-weim", | |
130 | .of_match_table = weim_id_table, | |
131 | }, | |
132 | .probe = weim_probe, | |
133 | }; | |
134 | ||
135 | module_platform_driver(weim_driver); | |
136 | MODULE_AUTHOR("Freescale Semiconductor Inc."); | |
137 | MODULE_DESCRIPTION("i.MX EIM Controller Driver"); | |
138 | MODULE_LICENSE("GPL"); |