drivers/hwspinlock/stm32_hwspinlock.c

   1 // SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
   2 /*
   3  * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
   4  */
   5
   6 #define LOG_CATEGORY UCLASS_HWSPINLOCK
   7
   8 #include <common.h>
   9 #include <clk.h>
  10 #include <dm.h>
  11 #include <hwspinlock.h>
  12 #include <malloc.h>
  13 #include <asm/io.h>
  14 #include <linux/bitops.h>
  15
  16 #define STM32_MUTEX_COREID      BIT(8)
  17 #define STM32_MUTEX_LOCK_BIT    BIT(31)
  18 #define STM32_MUTEX_NUM_LOCKS   32
  19
  20 struct stm32mp1_hws_priv {
  21         fdt_addr_t base;
  22 };
  23
  24 static int stm32mp1_lock(struct udevice *dev, int index)
  25 {
  26         struct stm32mp1_hws_priv *priv = dev_get_priv(dev);
  27         u32 status;
  28
  29         if (index >= STM32_MUTEX_NUM_LOCKS)
  30                 return -EINVAL;
  31
  32         status = readl(priv->base + index * sizeof(u32));
  33         if (status == (STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID))
  34                 return -EBUSY;
  35
  36         writel(STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID,
  37                priv->base + index * sizeof(u32));
  38
  39         status = readl(priv->base + index * sizeof(u32));
  40         if (status != (STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID))
  41                 return -EINVAL;
  42
  43         return 0;
  44 }
  45
  46 static int stm32mp1_unlock(struct udevice *dev, int index)
  47 {
  48         struct stm32mp1_hws_priv *priv = dev_get_priv(dev);
  49
  50         if (index >= STM32_MUTEX_NUM_LOCKS)
  51                 return -EINVAL;
  52
  53         writel(STM32_MUTEX_COREID, priv->base + index * sizeof(u32));
  54
  55         return 0;
  56 }
  57
  58 static int stm32mp1_hwspinlock_probe(struct udevice *dev)
  59 {
  60         struct stm32mp1_hws_priv *priv = dev_get_priv(dev);
  61         struct clk clk;
  62         int ret;
  63
  64         priv->base = dev_read_addr(dev);
  65         if (priv->base == FDT_ADDR_T_NONE)
  66                 return -EINVAL;
  67
  68         ret = clk_get_by_index(dev, 0, &clk);
  69         if (ret)
  70                 return ret;
  71
  72         ret = clk_enable(&clk);
  73         if (ret)
  74                 clk_free(&clk);
  75
  76         return ret;
  77 }
  78
  79 static const struct hwspinlock_ops stm32mp1_hwspinlock_ops = {
  80         .lock = stm32mp1_lock,
  81         .unlock = stm32mp1_unlock,
  82 };
  83
  84 static const struct udevice_id stm32mp1_hwspinlock_ids[] = {
  85         { .compatible = "st,stm32-hwspinlock" },
  86         {}
  87 };
  88
  89 U_BOOT_DRIVER(hwspinlock_stm32mp1) = {
  90         .name = "hwspinlock_stm32mp1",
  91         .id = UCLASS_HWSPINLOCK,
  92         .of_match = stm32mp1_hwspinlock_ids,
  93         .ops = &stm32mp1_hwspinlock_ops,
  94         .probe = stm32mp1_hwspinlock_probe,
  95         .priv_auto      = sizeof(struct stm32mp1_hws_priv),
  96 };