xref: /openbmc/linux/drivers/crypto/ccree/cc_pm.c (revision b8a94bfb)
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 static int cc_pm_suspend(struct device *dev)
19 {
20 	struct cc_drvdata *drvdata = dev_get_drvdata(dev);
21 
22 	dev_dbg(dev, "set HOST_POWER_DOWN_EN\n");
23 	fini_cc_regs(drvdata);
24 	cc_iowrite(drvdata, CC_REG(HOST_POWER_DOWN_EN), POWER_DOWN_ENABLE);
25 	clk_disable_unprepare(drvdata->clk);
26 	return 0;
27 }
28 
29 static int cc_pm_resume(struct device *dev)
30 {
31 	int rc;
32 	struct cc_drvdata *drvdata = dev_get_drvdata(dev);
33 
34 	dev_dbg(dev, "unset HOST_POWER_DOWN_EN\n");
35 	/* Enables the device source clk */
36 	rc = clk_prepare_enable(drvdata->clk);
37 	if (rc) {
38 		dev_err(dev, "failed getting clock back on. We're toast.\n");
39 		return rc;
40 	}
41 	/* wait for Cryptocell reset completion */
42 	if (!cc_wait_for_reset_completion(drvdata)) {
43 		dev_err(dev, "Cryptocell reset not completed");
44 		clk_disable_unprepare(drvdata->clk);
45 		return -EBUSY;
46 	}
47 
48 	cc_iowrite(drvdata, CC_REG(HOST_POWER_DOWN_EN), POWER_DOWN_DISABLE);
49 	rc = init_cc_regs(drvdata);
50 	if (rc) {
51 		dev_err(dev, "init_cc_regs (%x)\n", rc);
52 		clk_disable_unprepare(drvdata->clk);
53 		return rc;
54 	}
55 	/* check if tee fips error occurred during power down */
56 	cc_tee_handle_fips_error(drvdata);
57 
58 	cc_init_hash_sram(drvdata);
59 
60 	return 0;
61 }
62 
63 const struct dev_pm_ops ccree_pm = {
64 	SET_RUNTIME_PM_OPS(cc_pm_suspend, cc_pm_resume, NULL)
65 };
66 
67 int cc_pm_get(struct device *dev)
68 {
69 	int rc = pm_runtime_get_sync(dev);
70 	if (rc < 0) {
71 		pm_runtime_put_noidle(dev);
72 		return rc;
73 	}
74 
75 	return 0;
76 }
77 
78 void cc_pm_put_suspend(struct device *dev)
79 {
80 	pm_runtime_mark_last_busy(dev);
81 	pm_runtime_put_autosuspend(dev);
82 }
83