xref: /openbmc/linux/drivers/crypto/ccree/cc_pm.c (revision 0e17c50f)
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_hash.h"
12 #include "cc_pm.h"
13 #include "cc_fips.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 
26 	dev_dbg(dev, "set HOST_POWER_DOWN_EN\n");
27 	fini_cc_regs(drvdata);
28 	cc_iowrite(drvdata, CC_REG(HOST_POWER_DOWN_EN), POWER_DOWN_ENABLE);
29 	cc_clk_off(drvdata);
30 	return 0;
31 }
32 
33 int cc_pm_resume(struct device *dev)
34 {
35 	int rc;
36 	struct cc_drvdata *drvdata = dev_get_drvdata(dev);
37 
38 	dev_dbg(dev, "unset HOST_POWER_DOWN_EN\n");
39 	/* Enables the device source clk */
40 	rc = cc_clk_on(drvdata);
41 	if (rc) {
42 		dev_err(dev, "failed getting clock back on. We're toast.\n");
43 		return rc;
44 	}
45 	/* wait for Cryptocell reset completion */
46 	if (!cc_wait_for_reset_completion(drvdata)) {
47 		dev_err(dev, "Cryptocell reset not completed");
48 		return -EBUSY;
49 	}
50 
51 	cc_iowrite(drvdata, CC_REG(HOST_POWER_DOWN_EN), POWER_DOWN_DISABLE);
52 	rc = init_cc_regs(drvdata, false);
53 	if (rc) {
54 		dev_err(dev, "init_cc_regs (%x)\n", rc);
55 		return rc;
56 	}
57 	/* check if tee fips error occurred during power down */
58 	cc_tee_handle_fips_error(drvdata);
59 
60 	cc_init_hash_sram(drvdata);
61 
62 	return 0;
63 }
64 
65 int cc_pm_get(struct device *dev)
66 {
67 	int rc = 0;
68 	struct cc_drvdata *drvdata = dev_get_drvdata(dev);
69 
70 	if (drvdata->pm_on)
71 		rc = pm_runtime_get_sync(dev);
72 
73 	return (rc == 1 ? 0 : rc);
74 }
75 
76 void cc_pm_put_suspend(struct device *dev)
77 {
78 	struct cc_drvdata *drvdata = dev_get_drvdata(dev);
79 
80 	if (drvdata->pm_on) {
81 		pm_runtime_mark_last_busy(dev);
82 		pm_runtime_put_autosuspend(dev);
83 	}
84 }
85 
86 bool cc_pm_is_dev_suspended(struct device *dev)
87 {
88 	/* check device state using runtime api */
89 	return pm_runtime_suspended(dev);
90 }
91 
92 int cc_pm_init(struct cc_drvdata *drvdata)
93 {
94 	struct device *dev = drvdata_to_dev(drvdata);
95 
96 	/* must be before the enabling to avoid redundant suspending */
97 	pm_runtime_set_autosuspend_delay(dev, CC_SUSPEND_TIMEOUT);
98 	pm_runtime_use_autosuspend(dev);
99 	/* set us as active - note we won't do PM ops until cc_pm_go()! */
100 	return pm_runtime_set_active(dev);
101 }
102 
103 /* enable the PM module*/
104 void cc_pm_go(struct cc_drvdata *drvdata)
105 {
106 	pm_runtime_enable(drvdata_to_dev(drvdata));
107 	drvdata->pm_on = true;
108 }
109 
110 void cc_pm_fini(struct cc_drvdata *drvdata)
111 {
112 	pm_runtime_disable(drvdata_to_dev(drvdata));
113 	drvdata->pm_on = false;
114 }
115