drivers/crypto/ccree/cc_pm.c

   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 }