xref: /openbmc/linux/drivers/crypto/ccree/cc_pm.c (revision 2169e6da)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2012-2019 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 #include "cc_fips.h"
15 
16 #define POWER_DOWN_ENABLE 0x01
17 #define POWER_DOWN_DISABLE 0x00
18 
19 const struct dev_pm_ops ccree_pm = {
20 	SET_RUNTIME_PM_OPS(cc_pm_suspend, cc_pm_resume, NULL)
21 };
22 
23 int cc_pm_suspend(struct device *dev)
24 {
25 	struct cc_drvdata *drvdata = dev_get_drvdata(dev);
26 	int rc;
27 
28 	dev_dbg(dev, "set HOST_POWER_DOWN_EN\n");
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_iowrite(drvdata, CC_REG(HOST_POWER_DOWN_EN), POWER_DOWN_ENABLE);
36 	cc_clk_off(drvdata);
37 	return 0;
38 }
39 
40 int cc_pm_resume(struct device *dev)
41 {
42 	int rc;
43 	struct cc_drvdata *drvdata = dev_get_drvdata(dev);
44 
45 	dev_dbg(dev, "unset HOST_POWER_DOWN_EN\n");
46 	/* Enables the device source clk */
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 	/* wait for Crytpcell reset completion */
53 	if (!cc_wait_for_reset_completion(drvdata)) {
54 		dev_err(dev, "Cryptocell reset not completed");
55 		return -EBUSY;
56 	}
57 
58 	cc_iowrite(drvdata, CC_REG(HOST_POWER_DOWN_EN), POWER_DOWN_DISABLE);
59 	rc = init_cc_regs(drvdata, false);
60 	if (rc) {
61 		dev_err(dev, "init_cc_regs (%x)\n", rc);
62 		return rc;
63 	}
64 	/* check if tee fips error occurred during power down */
65 	cc_tee_handle_fips_error(drvdata);
66 
67 	rc = cc_resume_req_queue(drvdata);
68 	if (rc) {
69 		dev_err(dev, "cc_resume_req_queue (%x)\n", rc);
70 		return rc;
71 	}
72 
73 	/* must be after the queue resuming as it uses the HW queue*/
74 	cc_init_hash_sram(drvdata);
75 
76 	cc_init_iv_sram(drvdata);
77 	return 0;
78 }
79 
80 int cc_pm_get(struct device *dev)
81 {
82 	int rc = 0;
83 	struct cc_drvdata *drvdata = dev_get_drvdata(dev);
84 
85 	if (cc_req_queue_suspended(drvdata))
86 		rc = pm_runtime_get_sync(dev);
87 	else
88 		pm_runtime_get_noresume(dev);
89 
90 	return rc;
91 }
92 
93 int cc_pm_put_suspend(struct device *dev)
94 {
95 	int rc = 0;
96 	struct cc_drvdata *drvdata = dev_get_drvdata(dev);
97 
98 	if (!cc_req_queue_suspended(drvdata)) {
99 		pm_runtime_mark_last_busy(dev);
100 		rc = pm_runtime_put_autosuspend(dev);
101 	} else {
102 		/* Something wrong happens*/
103 		dev_err(dev, "request to suspend already suspended queue");
104 		rc = -EBUSY;
105 	}
106 	return rc;
107 }
108 
109 bool cc_pm_is_dev_suspended(struct device *dev)
110 {
111 	/* check device state using runtime api */
112 	return pm_runtime_suspended(dev);
113 }
114 
115 int cc_pm_init(struct cc_drvdata *drvdata)
116 {
117 	struct device *dev = drvdata_to_dev(drvdata);
118 
119 	/* must be before the enabling to avoid resdundent suspending */
120 	pm_runtime_set_autosuspend_delay(dev, CC_SUSPEND_TIMEOUT);
121 	pm_runtime_use_autosuspend(dev);
122 	/* activate the PM module */
123 	return pm_runtime_set_active(dev);
124 }
125 
126 /* enable the PM module*/
127 void cc_pm_go(struct cc_drvdata *drvdata)
128 {
129 	pm_runtime_enable(drvdata_to_dev(drvdata));
130 }
131 
132 void cc_pm_fini(struct cc_drvdata *drvdata)
133 {
134 	pm_runtime_disable(drvdata_to_dev(drvdata));
135 }
136