xref: /openbmc/linux/drivers/crypto/ccree/cc_pm.c (revision a48c7709)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2012-2018 ARM Limited or its affiliates. */
3 
4 #include <linux/kernel.h>
5 #include <linux/interrupt.h>
6 #include <linux/pm_runtime.h>
7 #include "cc_driver.h"
8 #include "cc_buffer_mgr.h"
9 #include "cc_request_mgr.h"
10 #include "cc_sram_mgr.h"
11 #include "cc_ivgen.h"
12 #include "cc_hash.h"
13 #include "cc_pm.h"
14 
15 #define POWER_DOWN_ENABLE 0x01
16 #define POWER_DOWN_DISABLE 0x00
17 
18 const struct dev_pm_ops ccree_pm = {
19 	SET_RUNTIME_PM_OPS(cc_pm_suspend, cc_pm_resume, NULL)
20 };
21 
22 int cc_pm_suspend(struct device *dev)
23 {
24 	struct cc_drvdata *drvdata = dev_get_drvdata(dev);
25 	int rc;
26 
27 	dev_dbg(dev, "set HOST_POWER_DOWN_EN\n");
28 	cc_iowrite(drvdata, CC_REG(HOST_POWER_DOWN_EN), POWER_DOWN_ENABLE);
29 	rc = cc_suspend_req_queue(drvdata);
30 	if (rc) {
31 		dev_err(dev, "cc_suspend_req_queue (%x)\n", rc);
32 		return rc;
33 	}
34 	fini_cc_regs(drvdata);
35 	cc_clk_off(drvdata);
36 	return 0;
37 }
38 
39 int cc_pm_resume(struct device *dev)
40 {
41 	int rc;
42 	struct cc_drvdata *drvdata = dev_get_drvdata(dev);
43 
44 	dev_dbg(dev, "unset HOST_POWER_DOWN_EN\n");
45 	cc_iowrite(drvdata, CC_REG(HOST_POWER_DOWN_EN), POWER_DOWN_DISABLE);
46 
47 	rc = cc_clk_on(drvdata);
48 	if (rc) {
49 		dev_err(dev, "failed getting clock back on. We're toast.\n");
50 		return rc;
51 	}
52 
53 	rc = init_cc_regs(drvdata, false);
54 	if (rc) {
55 		dev_err(dev, "init_cc_regs (%x)\n", rc);
56 		return rc;
57 	}
58 
59 	rc = cc_resume_req_queue(drvdata);
60 	if (rc) {
61 		dev_err(dev, "cc_resume_req_queue (%x)\n", rc);
62 		return rc;
63 	}
64 
65 	/* must be after the queue resuming as it uses the HW queue*/
66 	cc_init_hash_sram(drvdata);
67 
68 	cc_init_iv_sram(drvdata);
69 	return 0;
70 }
71 
72 int cc_pm_get(struct device *dev)
73 {
74 	int rc = 0;
75 	struct cc_drvdata *drvdata = dev_get_drvdata(dev);
76 
77 	if (cc_req_queue_suspended(drvdata))
78 		rc = pm_runtime_get_sync(dev);
79 	else
80 		pm_runtime_get_noresume(dev);
81 
82 	return rc;
83 }
84 
85 int cc_pm_put_suspend(struct device *dev)
86 {
87 	int rc = 0;
88 	struct cc_drvdata *drvdata = dev_get_drvdata(dev);
89 
90 	if (!cc_req_queue_suspended(drvdata)) {
91 		pm_runtime_mark_last_busy(dev);
92 		rc = pm_runtime_put_autosuspend(dev);
93 	} else {
94 		/* Something wrong happens*/
95 		dev_err(dev, "request to suspend already suspended queue");
96 		rc = -EBUSY;
97 	}
98 	return rc;
99 }
100 
101 int cc_pm_init(struct cc_drvdata *drvdata)
102 {
103 	int rc = 0;
104 	struct device *dev = drvdata_to_dev(drvdata);
105 
106 	/* must be before the enabling to avoid resdundent suspending */
107 	pm_runtime_set_autosuspend_delay(dev, CC_SUSPEND_TIMEOUT);
108 	pm_runtime_use_autosuspend(dev);
109 	/* activate the PM module */
110 	rc = pm_runtime_set_active(dev);
111 	if (rc)
112 		return rc;
113 	/* enable the PM module*/
114 	pm_runtime_enable(dev);
115 
116 	return rc;
117 }
118 
119 void cc_pm_fini(struct cc_drvdata *drvdata)
120 {
121 	pm_runtime_disable(drvdata_to_dev(drvdata));
122 }
123