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