1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // rcpm.c - Freescale QorIQ RCPM driver
4 //
5 // Copyright 2019 NXP
6 //
7 // Author: Ran Wang <ran.wang_1@nxp.com>
8
9 #include <linux/init.h>
10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 #include <linux/of_address.h>
13 #include <linux/slab.h>
14 #include <linux/suspend.h>
15 #include <linux/kernel.h>
16
17 #define RCPM_WAKEUP_CELL_MAX_SIZE 7
18
19 struct rcpm {
20 unsigned int wakeup_cells;
21 void __iomem *ippdexpcr_base;
22 bool little_endian;
23 };
24
25 /**
26 * rcpm_pm_prepare - performs device-level tasks associated with power
27 * management, such as programming related to the wakeup source control.
28 * @dev: Device to handle.
29 *
30 */
rcpm_pm_prepare(struct device * dev)31 static int rcpm_pm_prepare(struct device *dev)
32 {
33 int i, ret, idx;
34 void __iomem *base;
35 struct wakeup_source *ws;
36 struct rcpm *rcpm;
37 struct device_node *np = dev->of_node;
38 u32 value[RCPM_WAKEUP_CELL_MAX_SIZE + 1];
39 u32 setting[RCPM_WAKEUP_CELL_MAX_SIZE] = {0};
40
41 rcpm = dev_get_drvdata(dev);
42 if (!rcpm)
43 return -EINVAL;
44
45 base = rcpm->ippdexpcr_base;
46 idx = wakeup_sources_read_lock();
47
48 /* Begin with first registered wakeup source */
49 for_each_wakeup_source(ws) {
50
51 /* skip object which is not attached to device */
52 if (!ws->dev || !ws->dev->parent)
53 continue;
54
55 ret = device_property_read_u32_array(ws->dev->parent,
56 "fsl,rcpm-wakeup", value,
57 rcpm->wakeup_cells + 1);
58
59 /* Wakeup source should refer to current rcpm device */
60 if (ret || (np->phandle != value[0]))
61 continue;
62
63 /* Property "#fsl,rcpm-wakeup-cells" of rcpm node defines the
64 * number of IPPDEXPCR register cells, and "fsl,rcpm-wakeup"
65 * of wakeup source IP contains an integer array: <phandle to
66 * RCPM node, IPPDEXPCR0 setting, IPPDEXPCR1 setting,
67 * IPPDEXPCR2 setting, etc>.
68 *
69 * So we will go thought them to collect setting data.
70 */
71 for (i = 0; i < rcpm->wakeup_cells; i++)
72 setting[i] |= value[i + 1];
73 }
74
75 wakeup_sources_read_unlock(idx);
76
77 /* Program all IPPDEXPCRn once */
78 for (i = 0; i < rcpm->wakeup_cells; i++) {
79 u32 tmp = setting[i];
80 void __iomem *address = base + i * 4;
81
82 if (!tmp)
83 continue;
84
85 /* We can only OR related bits */
86 if (rcpm->little_endian) {
87 tmp |= ioread32(address);
88 iowrite32(tmp, address);
89 } else {
90 tmp |= ioread32be(address);
91 iowrite32be(tmp, address);
92 }
93 }
94
95 return 0;
96 }
97
98 static const struct dev_pm_ops rcpm_pm_ops = {
99 .prepare = rcpm_pm_prepare,
100 };
101
rcpm_probe(struct platform_device * pdev)102 static int rcpm_probe(struct platform_device *pdev)
103 {
104 struct device *dev = &pdev->dev;
105 struct resource *r;
106 struct rcpm *rcpm;
107 int ret;
108
109 rcpm = devm_kzalloc(dev, sizeof(*rcpm), GFP_KERNEL);
110 if (!rcpm)
111 return -ENOMEM;
112
113 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
114 if (!r)
115 return -ENODEV;
116
117 rcpm->ippdexpcr_base = devm_ioremap_resource(&pdev->dev, r);
118 if (IS_ERR(rcpm->ippdexpcr_base)) {
119 ret = PTR_ERR(rcpm->ippdexpcr_base);
120 return ret;
121 }
122
123 rcpm->little_endian = device_property_read_bool(
124 &pdev->dev, "little-endian");
125
126 ret = device_property_read_u32(&pdev->dev,
127 "#fsl,rcpm-wakeup-cells", &rcpm->wakeup_cells);
128 if (ret)
129 return ret;
130
131 dev_set_drvdata(&pdev->dev, rcpm);
132
133 return 0;
134 }
135
136 static const struct of_device_id rcpm_of_match[] = {
137 { .compatible = "fsl,qoriq-rcpm-2.1+", },
138 {}
139 };
140 MODULE_DEVICE_TABLE(of, rcpm_of_match);
141
142 static struct platform_driver rcpm_driver = {
143 .driver = {
144 .name = "rcpm",
145 .of_match_table = rcpm_of_match,
146 .pm = &rcpm_pm_ops,
147 },
148 .probe = rcpm_probe,
149 };
150
151 module_platform_driver(rcpm_driver);
152