drivers/hwspinlock/sprd_hwspinlock.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Spreadtrum hardware spinlock driver
   4  * Copyright (C) 2017 Spreadtrum  - http://www.spreadtrum.com
   5  */
   6
   7 #include <linux/bitops.h>
   8 #include <linux/clk.h>
   9 #include <linux/delay.h>
  10 #include <linux/device.h>
  11 #include <linux/hwspinlock.h>
  12 #include <linux/io.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/of.h>
  16 #include <linux/of_device.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/slab.h>
  19
  20 #include "hwspinlock_internal.h"
  21
  22 /* hwspinlock registers definition */
  23 #define HWSPINLOCK_RECCTRL              0x4
  24 #define HWSPINLOCK_MASTERID(_X_)        (0x80 + 0x4 * (_X_))
  25 #define HWSPINLOCK_TOKEN(_X_)           (0x800 + 0x4 * (_X_))
  26
  27 /* unlocked value */
  28 #define HWSPINLOCK_NOTTAKEN             0x55aa10c5
  29 /* bits definition of RECCTRL reg */
  30 #define HWSPINLOCK_USER_BITS            0x1
  31
  32 /* hwspinlock number */
  33 #define SPRD_HWLOCKS_NUM                32
  34
  35 struct sprd_hwspinlock_dev {
  36         void __iomem *base;
  37         struct clk *clk;
  38         struct hwspinlock_device bank;
  39 };
  40
  41 /* try to lock the hardware spinlock */
  42 static int sprd_hwspinlock_trylock(struct hwspinlock *lock)
  43 {
  44         struct sprd_hwspinlock_dev *sprd_hwlock =
  45                 dev_get_drvdata(lock->bank->dev);
  46         void __iomem *addr = lock->priv;
  47         int user_id, lock_id;
  48
  49         if (!readl(addr))
  50                 return 1;
  51
  52         lock_id = hwlock_to_id(lock);
  53         /* get the hardware spinlock master/user id */
  54         user_id = readl(sprd_hwlock->base + HWSPINLOCK_MASTERID(lock_id));
  55         dev_warn(sprd_hwlock->bank.dev,
  56                  "hwspinlock [%d] lock failed and master/user id = %d!\n",
  57                  lock_id, user_id);
  58         return 0;
  59 }
  60
  61 /* unlock the hardware spinlock */
  62 static void sprd_hwspinlock_unlock(struct hwspinlock *lock)
  63 {
  64         void __iomem *lock_addr = lock->priv;
  65
  66         writel(HWSPINLOCK_NOTTAKEN, lock_addr);
  67 }
  68
  69 /* The specs recommended below number as the retry delay time */
  70 static void sprd_hwspinlock_relax(struct hwspinlock *lock)
  71 {
  72         ndelay(10);
  73 }
  74
  75 static const struct hwspinlock_ops sprd_hwspinlock_ops = {
  76         .trylock = sprd_hwspinlock_trylock,
  77         .unlock = sprd_hwspinlock_unlock,
  78         .relax = sprd_hwspinlock_relax,
  79 };
  80
  81 static void sprd_hwspinlock_disable(void *data)
  82 {
  83         struct sprd_hwspinlock_dev *sprd_hwlock = data;
  84
  85         clk_disable_unprepare(sprd_hwlock->clk);
  86 }
  87
  88 static int sprd_hwspinlock_probe(struct platform_device *pdev)
  89 {
  90         struct sprd_hwspinlock_dev *sprd_hwlock;
  91         struct hwspinlock *lock;
  92         int i, ret;
  93
  94         if (!pdev->dev.of_node)
  95                 return -ENODEV;
  96
  97         sprd_hwlock = devm_kzalloc(&pdev->dev,
  98                                    sizeof(struct sprd_hwspinlock_dev) +
  99                                    SPRD_HWLOCKS_NUM * sizeof(*lock),
 100                                    GFP_KERNEL);
 101         if (!sprd_hwlock)
 102                 return -ENOMEM;
 103
 104         sprd_hwlock->base = devm_platform_ioremap_resource(pdev, 0);
 105         if (IS_ERR(sprd_hwlock->base))
 106                 return PTR_ERR(sprd_hwlock->base);
 107
 108         sprd_hwlock->clk = devm_clk_get(&pdev->dev, "enable");
 109         if (IS_ERR(sprd_hwlock->clk)) {
 110                 dev_err(&pdev->dev, "get hwspinlock clock failed!\n");
 111                 return PTR_ERR(sprd_hwlock->clk);
 112         }
 113
 114         ret = clk_prepare_enable(sprd_hwlock->clk);
 115         if (ret)
 116                 return ret;
 117
 118         ret = devm_add_action_or_reset(&pdev->dev, sprd_hwspinlock_disable,
 119                                        sprd_hwlock);
 120         if (ret) {
 121                 dev_err(&pdev->dev,
 122                         "Failed to add hwspinlock disable action\n");
 123                 return ret;
 124         }
 125
 126         /* set the hwspinlock to record user id to identify subsystems */
 127         writel(HWSPINLOCK_USER_BITS, sprd_hwlock->base + HWSPINLOCK_RECCTRL);
 128
 129         for (i = 0; i < SPRD_HWLOCKS_NUM; i++) {
 130                 lock = &sprd_hwlock->bank.lock[i];
 131                 lock->priv = sprd_hwlock->base + HWSPINLOCK_TOKEN(i);
 132         }
 133
 134         platform_set_drvdata(pdev, sprd_hwlock);
 135
 136         return devm_hwspin_lock_register(&pdev->dev, &sprd_hwlock->bank,
 137                                          &sprd_hwspinlock_ops, 0,
 138                                          SPRD_HWLOCKS_NUM);
 139 }
 140
 141 static const struct of_device_id sprd_hwspinlock_of_match[] = {
 142         { .compatible = "sprd,hwspinlock-r3p0", },
 143         { /* sentinel */ }
 144 };
 145 MODULE_DEVICE_TABLE(of, sprd_hwspinlock_of_match);
 146
 147 static struct platform_driver sprd_hwspinlock_driver = {
 148         .probe = sprd_hwspinlock_probe,
 149         .driver = {
 150                 .name = "sprd_hwspinlock",
 151                 .of_match_table = of_match_ptr(sprd_hwspinlock_of_match),
 152         },
 153 };
 154
 155 static int __init sprd_hwspinlock_init(void)
 156 {
 157         return platform_driver_register(&sprd_hwspinlock_driver);
 158 }
 159 postcore_initcall(sprd_hwspinlock_init);
 160
 161 static void __exit sprd_hwspinlock_exit(void)
 162 {
 163         platform_driver_unregister(&sprd_hwspinlock_driver);
 164 }
 165 module_exit(sprd_hwspinlock_exit);
 166
 167 MODULE_LICENSE("GPL v2");
 168 MODULE_DESCRIPTION("Hardware spinlock driver for Spreadtrum");
 169 MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
 170 MODULE_AUTHOR("Lanqing Liu <lanqing.liu@spreadtrum.com>");
 171 MODULE_AUTHOR("Long Cheng <aiden.cheng@spreadtrum.com>");