drivers/sysreset/sysreset_ast.c

   1 /*
   2  * (C) Copyright 2016 Google, Inc
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0
   5  */
   6
   7 #include <common.h>
   8 #include <dm.h>
   9 #include <errno.h>
  10 #include <sysreset.h>
  11 #include <asm/io.h>
  12 #include <asm/arch/wdt.h>
  13 #include <linux/err.h>
  14
  15 /* Number of Watchdog Timer ticks before reset */
  16 #define AST_WDT_RESET_TIMEOUT   10
  17 #define AST_WDT_FOR_RESET       0
  18
  19 static int ast_sysreset_request(struct udevice *dev, enum sysreset_t type)
  20 {
  21         struct ast_wdt *wdt = ast_get_wdt(AST_WDT_FOR_RESET);
  22         u32 reset_mode = 0;
  23
  24         if (IS_ERR(wdt))
  25                 return PTR_ERR(wdt);
  26
  27         switch (type) {
  28         case SYSRESET_WARM:
  29                 reset_mode = WDT_CTRL_RESET_CPU;
  30                 break;
  31         case SYSRESET_COLD:
  32                 reset_mode = WDT_CTRL_RESET_CHIP;
  33                 break;
  34         default:
  35                 return -EPROTONOSUPPORT;
  36         }
  37
  38         /* Clear reset mode bits */
  39         clrsetbits_le32(&wdt->ctrl,
  40                         (WDT_CTRL_RESET_MODE_MASK << WDT_CTRL_RESET_MODE_SHIFT),
  41                         (reset_mode << WDT_CTRL_RESET_MODE_SHIFT));
  42         wdt_start(wdt, AST_WDT_RESET_TIMEOUT);
  43
  44         return -EINPROGRESS;
  45 }
  46
  47 static struct sysreset_ops ast_sysreset = {
  48         .request        = ast_sysreset_request,
  49 };
  50
  51 U_BOOT_DRIVER(sysreset_ast) = {
  52         .name   = "ast_sysreset",
  53         .id     = UCLASS_SYSRESET,
  54         .ops    = &ast_sysreset,
  55 };