drivers/watchdog/ast2600_wdt.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2020 Aspeed Technology, Inc
   4  */
   5
   6 #include <common.h>
   7 #include <dm.h>
   8 #include <errno.h>
   9 #include <log.h>
  10 #include <wdt.h>
  11 #include <asm/io.h>
  12 #include <asm/arch/wdt_ast2600.h>
  13 #include <linux/err.h>
  14
  15 struct ast2600_wdt_priv {
  16         struct ast2600_wdt *regs;
  17 };
  18
  19 static int ast2600_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
  20 {
  21         struct ast2600_wdt_priv *priv = dev_get_priv(dev);
  22         struct ast2600_wdt *wdt = priv->regs;
  23
  24         /* WDT counts in the 1MHz frequency, namely 1us */
  25         writel((u32)(timeout_ms * 1000), &wdt->counter_reload_val);
  26         writel(WDT_COUNTER_RESTART_VAL, &wdt->counter_restart);
  27         writel(WDT_CTRL_EN | WDT_CTRL_RESET, &wdt->ctrl);
  28
  29         return 0;
  30 }
  31
  32 static int ast2600_wdt_stop(struct udevice *dev)
  33 {
  34         struct ast2600_wdt_priv *priv = dev_get_priv(dev);
  35         struct ast2600_wdt *wdt = priv->regs;
  36
  37         clrbits_le32(&wdt->ctrl, WDT_CTRL_EN);
  38
  39         writel(WDT_RESET_MASK1_DEFAULT, &wdt->reset_mask1);
  40         writel(WDT_RESET_MASK2_DEFAULT, &wdt->reset_mask2);
  41
  42         return 0;
  43 }
  44
  45 static int ast2600_wdt_reset(struct udevice *dev)
  46 {
  47         struct ast2600_wdt_priv *priv = dev_get_priv(dev);
  48         struct ast2600_wdt *wdt = priv->regs;
  49
  50         writel(WDT_COUNTER_RESTART_VAL, &wdt->counter_restart);
  51
  52         return 0;
  53 }
  54
  55 static int ast2600_wdt_expire_now(struct udevice *dev, ulong flags)
  56 {
  57         int ret;
  58         struct ast2600_wdt_priv *priv = dev_get_priv(dev);
  59         struct ast2600_wdt *wdt = priv->regs;
  60
  61         ret = ast2600_wdt_start(dev, 1, flags);
  62         if (ret)
  63                 return ret;
  64
  65         while (readl(&wdt->ctrl) & WDT_CTRL_EN)
  66                 ;
  67
  68         return ast2600_wdt_stop(dev);
  69 }
  70
  71 static int ast2600_wdt_of_to_plat(struct udevice *dev)
  72 {
  73         struct ast2600_wdt_priv *priv = dev_get_priv(dev);
  74
  75         priv->regs = dev_read_addr_ptr(dev);
  76         if (!priv->regs)
  77                 return -EINVAL;
  78
  79         return 0;
  80 }
  81
  82 static const struct wdt_ops ast2600_wdt_ops = {
  83         .start = ast2600_wdt_start,
  84         .reset = ast2600_wdt_reset,
  85         .stop = ast2600_wdt_stop,
  86         .expire_now = ast2600_wdt_expire_now,
  87 };
  88
  89 static const struct udevice_id ast2600_wdt_ids[] = {
  90         { .compatible = "aspeed,ast2600-wdt" },
  91         { }
  92 };
  93
  94 static int ast2600_wdt_probe(struct udevice *dev)
  95 {
  96         debug("%s() wdt%u\n", __func__, dev_seq(dev));
  97         ast2600_wdt_stop(dev);
  98
  99         return 0;
 100 }
 101
 102 U_BOOT_DRIVER(ast2600_wdt) = {
 103         .name = "ast2600_wdt",
 104         .id = UCLASS_WDT,
 105         .of_match = ast2600_wdt_ids,
 106         .probe = ast2600_wdt_probe,
 107         .priv_auto = sizeof(struct ast2600_wdt_priv),
 108         .of_to_plat = ast2600_wdt_of_to_plat,
 109         .ops = &ast2600_wdt_ops,
 110 };