xref: /linux/drivers/hwtracing/coresight/coresight-replicator.c (revision 005438a8eef063495ac059d128eea71b58de50e5)
1 /* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
2  *
3  * This program is free software; you can redistribute it and/or modify
4  * it under the terms of the GNU General Public License version 2 and
5  * only version 2 as published by the Free Software Foundation.
6  *
7  * This program is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10  * GNU General Public License for more details.
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/device.h>
17 #include <linux/platform_device.h>
18 #include <linux/io.h>
19 #include <linux/err.h>
20 #include <linux/slab.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/clk.h>
23 #include <linux/of.h>
24 #include <linux/coresight.h>
25 
26 #include "coresight-priv.h"
27 
28 /**
29  * struct replicator_drvdata - specifics associated to a replicator component
30  * @dev:	the device entity associated with this component
31  * @atclk:	optional clock for the core parts of the replicator.
32  * @csdev:	component vitals needed by the framework
33  */
34 struct replicator_drvdata {
35 	struct device		*dev;
36 	struct clk		*atclk;
37 	struct coresight_device	*csdev;
38 };
39 
40 static int replicator_enable(struct coresight_device *csdev, int inport,
41 			     int outport)
42 {
43 	struct replicator_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
44 
45 	pm_runtime_get_sync(drvdata->dev);
46 	dev_info(drvdata->dev, "REPLICATOR enabled\n");
47 	return 0;
48 }
49 
50 static void replicator_disable(struct coresight_device *csdev, int inport,
51 			       int outport)
52 {
53 	struct replicator_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
54 
55 	pm_runtime_put(drvdata->dev);
56 	dev_info(drvdata->dev, "REPLICATOR disabled\n");
57 }
58 
59 static const struct coresight_ops_link replicator_link_ops = {
60 	.enable		= replicator_enable,
61 	.disable	= replicator_disable,
62 };
63 
64 static const struct coresight_ops replicator_cs_ops = {
65 	.link_ops	= &replicator_link_ops,
66 };
67 
68 static int replicator_probe(struct platform_device *pdev)
69 {
70 	int ret;
71 	struct device *dev = &pdev->dev;
72 	struct coresight_platform_data *pdata = NULL;
73 	struct replicator_drvdata *drvdata;
74 	struct coresight_desc *desc;
75 	struct device_node *np = pdev->dev.of_node;
76 
77 	if (np) {
78 		pdata = of_get_coresight_platform_data(dev, np);
79 		if (IS_ERR(pdata))
80 			return PTR_ERR(pdata);
81 		pdev->dev.platform_data = pdata;
82 	}
83 
84 	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
85 	if (!drvdata)
86 		return -ENOMEM;
87 
88 	drvdata->dev = &pdev->dev;
89 	drvdata->atclk = devm_clk_get(&pdev->dev, "atclk"); /* optional */
90 	if (!IS_ERR(drvdata->atclk)) {
91 		ret = clk_prepare_enable(drvdata->atclk);
92 		if (ret)
93 			return ret;
94 	}
95 	pm_runtime_get_noresume(&pdev->dev);
96 	pm_runtime_set_active(&pdev->dev);
97 	pm_runtime_enable(&pdev->dev);
98 	platform_set_drvdata(pdev, drvdata);
99 
100 	desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
101 	if (!desc) {
102 		ret = -ENOMEM;
103 		goto out_disable_pm;
104 	}
105 
106 	desc->type = CORESIGHT_DEV_TYPE_LINK;
107 	desc->subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_SPLIT;
108 	desc->ops = &replicator_cs_ops;
109 	desc->pdata = pdev->dev.platform_data;
110 	desc->dev = &pdev->dev;
111 	drvdata->csdev = coresight_register(desc);
112 	if (IS_ERR(drvdata->csdev)) {
113 		ret = PTR_ERR(drvdata->csdev);
114 		goto out_disable_pm;
115 	}
116 
117 	pm_runtime_put(&pdev->dev);
118 
119 	dev_info(dev, "REPLICATOR initialized\n");
120 	return 0;
121 
122 out_disable_pm:
123 	if (!IS_ERR(drvdata->atclk))
124 		clk_disable_unprepare(drvdata->atclk);
125 	pm_runtime_put_noidle(&pdev->dev);
126 	pm_runtime_disable(&pdev->dev);
127 
128 	return ret;
129 }
130 
131 static int replicator_remove(struct platform_device *pdev)
132 {
133 	struct replicator_drvdata *drvdata = platform_get_drvdata(pdev);
134 
135 	coresight_unregister(drvdata->csdev);
136 	pm_runtime_get_sync(&pdev->dev);
137 	if (!IS_ERR(drvdata->atclk))
138 		clk_disable_unprepare(drvdata->atclk);
139 	pm_runtime_put_noidle(&pdev->dev);
140 	pm_runtime_disable(&pdev->dev);
141 
142 	return 0;
143 }
144 
145 #ifdef CONFIG_PM
146 static int replicator_runtime_suspend(struct device *dev)
147 {
148 	struct replicator_drvdata *drvdata = dev_get_drvdata(dev);
149 
150 	if (drvdata && !IS_ERR(drvdata->atclk))
151 		clk_disable_unprepare(drvdata->atclk);
152 
153 	return 0;
154 }
155 
156 static int replicator_runtime_resume(struct device *dev)
157 {
158 	struct replicator_drvdata *drvdata = dev_get_drvdata(dev);
159 
160 	if (drvdata && !IS_ERR(drvdata->atclk))
161 		clk_prepare_enable(drvdata->atclk);
162 
163 	return 0;
164 }
165 #endif
166 
167 static const struct dev_pm_ops replicator_dev_pm_ops = {
168 	SET_RUNTIME_PM_OPS(replicator_runtime_suspend,
169 			   replicator_runtime_resume, NULL)
170 };
171 
172 static const struct of_device_id replicator_match[] = {
173 	{.compatible = "arm,coresight-replicator"},
174 	{}
175 };
176 
177 static struct platform_driver replicator_driver = {
178 	.probe          = replicator_probe,
179 	.remove         = replicator_remove,
180 	.driver         = {
181 		.name   = "coresight-replicator",
182 		.of_match_table = replicator_match,
183 		.pm	= &replicator_dev_pm_ops,
184 	},
185 };
186 
187 static int __init replicator_init(void)
188 {
189 	return platform_driver_register(&replicator_driver);
190 }
191 module_init(replicator_init);
192 
193 static void __exit replicator_exit(void)
194 {
195 	platform_driver_unregister(&replicator_driver);
196 }
197 module_exit(replicator_exit);
198 
199 MODULE_LICENSE("GPL v2");
200 MODULE_DESCRIPTION("CoreSight Replicator driver");
201