drivers/hwspinlock/sprd_hwspinlock.c

   1 /*
   2  * Spreadtrum hardware spinlock driver
   3  * Copyright (C) 2017 Spreadtrum  - http://www.spreadtrum.com
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * version 2 as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  */
  14
  15 #include <linux/bitops.h>
  16 #include <linux/clk.h>
  17 #include <linux/delay.h>
  18 #include <linux/device.h>
  19 #include <linux/hwspinlock.h>
  20 #include <linux/io.h>
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/of.h>
  24 #include <linux/of_device.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/pm_runtime.h>
  27 #include <linux/slab.h>
  28
  29 #include "hwspinlock_internal.h"
  30
  31 /* hwspinlock registers definition */
  32 #define HWSPINLOCK_RECCTRL              0x4
  33 #define HWSPINLOCK_MASTERID(_X_)        (0x80 + 0x4 * (_X_))
  34 #define HWSPINLOCK_TOKEN(_X_)           (0x800 + 0x4 * (_X_))
  35
  36 /* unlocked value */
  37 #define HWSPINLOCK_NOTTAKEN             0x55aa10c5
  38 /* bits definition of RECCTRL reg */
  39 #define HWSPINLOCK_USER_BITS            0x1
  40
  41 /* hwspinlock number */
  42 #define SPRD_HWLOCKS_NUM                32
  43
  44 struct sprd_hwspinlock_dev {
  45         void __iomem *base;
  46         struct clk *clk;
  47         struct hwspinlock_device bank;
  48 };
  49
  50 /* try to lock the hardware spinlock */
  51 static int sprd_hwspinlock_trylock(struct hwspinlock *lock)
  52 {
  53         struct sprd_hwspinlock_dev *sprd_hwlock =
  54                 dev_get_drvdata(lock->bank->dev);
  55         void __iomem *addr = lock->priv;
  56         int user_id, lock_id;
  57
  58         if (!readl(addr))
  59                 return 1;
  60
  61         lock_id = hwlock_to_id(lock);
  62         /* get the hardware spinlock master/user id */
  63         user_id = readl(sprd_hwlock->base + HWSPINLOCK_MASTERID(lock_id));
  64         dev_warn(sprd_hwlock->bank.dev,
  65                  "hwspinlock [%d] lock failed and master/user id = %d!\n",
  66                  lock_id, user_id);
  67         return 0;
  68 }
  69
  70 /* unlock the hardware spinlock */
  71 static void sprd_hwspinlock_unlock(struct hwspinlock *lock)
  72 {
  73         void __iomem *lock_addr = lock->priv;
  74
  75         writel(HWSPINLOCK_NOTTAKEN, lock_addr);
  76 }
  77
  78 /* The specs recommended below number as the retry delay time */
  79 static void sprd_hwspinlock_relax(struct hwspinlock *lock)
  80 {
  81         ndelay(10);
  82 }
  83
  84 static const struct hwspinlock_ops sprd_hwspinlock_ops = {
  85         .trylock = sprd_hwspinlock_trylock,
  86         .unlock = sprd_hwspinlock_unlock,
  87         .relax = sprd_hwspinlock_relax,
  88 };
  89
  90 static int sprd_hwspinlock_probe(struct platform_device *pdev)
  91 {
  92         struct sprd_hwspinlock_dev *sprd_hwlock;
  93         struct hwspinlock *lock;
  94         struct resource *res;
  95         int i, ret;
  96
  97         if (!pdev->dev.of_node)
  98                 return -ENODEV;
  99
 100         sprd_hwlock = devm_kzalloc(&pdev->dev,
 101                                    sizeof(struct sprd_hwspinlock_dev) +
 102                                    SPRD_HWLOCKS_NUM * sizeof(*lock),
 103                                    GFP_KERNEL);
 104         if (!sprd_hwlock)
 105                 return -ENOMEM;
 106
 107         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 108         sprd_hwlock->base = devm_ioremap_resource(&pdev->dev, res);
 109         if (IS_ERR(sprd_hwlock->base))
 110                 return PTR_ERR(sprd_hwlock->base);
 111
 112         sprd_hwlock->clk = devm_clk_get(&pdev->dev, "enable");
 113         if (IS_ERR(sprd_hwlock->clk)) {
 114                 dev_err(&pdev->dev, "get hwspinlock clock failed!\n");
 115                 return PTR_ERR(sprd_hwlock->clk);
 116         }
 117
 118         clk_prepare_enable(sprd_hwlock->clk);
 119
 120         /* set the hwspinlock to record user id to identify subsystems */
 121         writel(HWSPINLOCK_USER_BITS, sprd_hwlock->base + HWSPINLOCK_RECCTRL);
 122
 123         for (i = 0; i < SPRD_HWLOCKS_NUM; i++) {
 124                 lock = &sprd_hwlock->bank.lock[i];
 125                 lock->priv = sprd_hwlock->base + HWSPINLOCK_TOKEN(i);
 126         }
 127
 128         platform_set_drvdata(pdev, sprd_hwlock);
 129         pm_runtime_enable(&pdev->dev);
 130
 131         ret = hwspin_lock_register(&sprd_hwlock->bank, &pdev->dev,
 132                                    &sprd_hwspinlock_ops, 0, SPRD_HWLOCKS_NUM);
 133         if (ret) {
 134                 pm_runtime_disable(&pdev->dev);
 135                 clk_disable_unprepare(sprd_hwlock->clk);
 136                 return ret;
 137         }
 138
 139         return 0;
 140 }
 141
 142 static int sprd_hwspinlock_remove(struct platform_device *pdev)
 143 {
 144         struct sprd_hwspinlock_dev *sprd_hwlock = platform_get_drvdata(pdev);
 145
 146         hwspin_lock_unregister(&sprd_hwlock->bank);
 147         pm_runtime_disable(&pdev->dev);
 148         clk_disable_unprepare(sprd_hwlock->clk);
 149         return 0;
 150 }
 151
 152 static const struct of_device_id sprd_hwspinlock_of_match[] = {
 153         { .compatible = "sprd,hwspinlock-r3p0", },
 154         { /* sentinel */ }
 155 };
 156 MODULE_DEVICE_TABLE(of, sprd_hwspinlock_of_match);
 157
 158 static struct platform_driver sprd_hwspinlock_driver = {
 159         .probe = sprd_hwspinlock_probe,
 160         .remove = sprd_hwspinlock_remove,
 161         .driver = {
 162                 .name = "sprd_hwspinlock",
 163                 .of_match_table = of_match_ptr(sprd_hwspinlock_of_match),
 164         },
 165 };
 166
 167 static int __init sprd_hwspinlock_init(void)
 168 {
 169         return platform_driver_register(&sprd_hwspinlock_driver);
 170 }
 171 postcore_initcall(sprd_hwspinlock_init);
 172
 173 static void __exit sprd_hwspinlock_exit(void)
 174 {
 175         platform_driver_unregister(&sprd_hwspinlock_driver);
 176 }
 177 module_exit(sprd_hwspinlock_exit);
 178
 179 MODULE_LICENSE("GPL v2");
 180 MODULE_DESCRIPTION("Hardware spinlock driver for Spreadtrum");
 181 MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
 182 MODULE_AUTHOR("Lanqing Liu <lanqing.liu@spreadtrum.com>");
 183 MODULE_AUTHOR("Long Cheng <aiden.cheng@spreadtrum.com>");