arch/arm/mach-aspeed/ast2500/clk_ast2500.c

   1 /*
   2  * Copyright (C) 2016 Google, Inc
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <common.h>
   8 #include <dm.h>
   9 #include <asm/io.h>
  10 #include <asm/arch/scu_ast2500.h>
  11
  12 int ast_get_clk(struct udevice **devp)
  13 {
  14         return uclass_get_device_by_driver(UCLASS_CLK,
  15                         DM_GET_DRIVER(aspeed_ast2500_scu), devp);
  16 }
  17
  18 void *ast_get_scu(void)
  19 {
  20         struct ast2500_clk_priv *priv;
  21         struct udevice *dev;
  22         int ret;
  23
  24         ret = ast_get_clk(&dev);
  25         if (ret)
  26                 return ERR_PTR(ret);
  27
  28         priv = dev_get_priv(dev);
  29
  30         return priv->scu;
  31 }
  32
  33 void ast_scu_unlock(struct ast2500_scu *scu)
  34 {
  35         writel(SCU_UNLOCK_VALUE, &scu->protection_key);
  36         while (!readl(&scu->protection_key))
  37                 ;
  38 }
  39
  40 void ast_scu_lock(struct ast2500_scu *scu)
  41 {
  42         writel(~SCU_UNLOCK_VALUE, &scu->protection_key);
  43         while (readl(&scu->protection_key))
  44                 ;
  45 }