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