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