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Diffstat (limited to 'drivers/bus/imx-weim.c')
-rw-r--r--drivers/bus/imx-weim.c138
1 files changed, 138 insertions, 0 deletions
diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
new file mode 100644
index 000000000000..349f14e886b7
--- /dev/null
+++ b/drivers/bus/imx-weim.c
@@ -0,0 +1,138 @@
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
15struct imx_weim {
16 void __iomem *base;
17 struct clk *clk;
18};
19
20static const struct of_device_id weim_id_table[] = {
21 { .compatible = "fsl,imx6q-weim", },
22 {}
23};
24MODULE_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. */
30static int
31weim_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
59static 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
83static 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
123weim_err:
124 return ret;
125}
126
127static 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
135module_platform_driver(weim_driver);
136MODULE_AUTHOR("Freescale Semiconductor Inc.");
137MODULE_DESCRIPTION("i.MX EIM Controller Driver");
138MODULE_LICENSE("GPL");