drivers/soc/actions/owl-sps-helper.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Actions Semi Owl Smart Power System (SPS) shared helpers
   4  *
   5  * Copyright 2012 Actions Semi Inc.
   6  * Author: Actions Semi, Inc.
   7  *
   8  * Copyright (c) 2017 Andreas Färber
   9  */
  10
  11 #include <linux/delay.h>
  12 #include <linux/io.h>
  13
  14 #define OWL_SPS_PG_CTL  0x0
  15
  16 int owl_sps_set_pg(void __iomem *base, u32 pwr_mask, u32 ack_mask, bool enable)
  17 {
  18         u32 val;
  19         bool ack;
  20         int timeout;
  21
  22         val = readl(base + OWL_SPS_PG_CTL);
  23         ack = val & ack_mask;
  24         if (ack == enable)
  25                 return 0;
  26
  27         if (enable)
  28                 val |= pwr_mask;
  29         else
  30                 val &= ~pwr_mask;
  31
  32         writel(val, base + OWL_SPS_PG_CTL);
  33
  34         for (timeout = 5000; timeout > 0; timeout -= 50) {
  35                 val = readl(base + OWL_SPS_PG_CTL);
  36                 if ((val & ack_mask) == (enable ? ack_mask : 0))
  37                         break;
  38                 udelay(50);
  39         }
  40         if (timeout <= 0)
  41                 return -ETIMEDOUT;
  42
  43         udelay(10);
  44
  45         return 0;
  46 }
  47 EXPORT_SYMBOL_GPL(owl_sps_set_pg);