LXR uboot/drivers/watchdog/octeontx

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Copyright (C) 2019 Marvell International Ltd.
   4 *
   5 * https://spdx.org/licenses
   6 */
   7
   8#include <clk.h>
   9#include <dm.h>
  10#include <errno.h>
  11#include <wdt.h>
  12#include <asm/global_data.h>
  13#include <asm/io.h>
  14#include <linux/bitfield.h>
  15
  16DECLARE_GLOBAL_DATA_PTR;
  17
  18#define CORE0_WDOG_OFFSET       0x40000
  19#define CORE0_POKE_OFFSET       0x50000
  20#define CORE0_POKE_OFFSET_MASK  0xfffffULL
  21
  22#define WDOG_MODE               GENMASK_ULL(1, 0)
  23#define WDOG_LEN                GENMASK_ULL(19, 4)
  24#define WDOG_CNT                GENMASK_ULL(43, 20)
  25
  26struct octeontx_wdt {
  27        void __iomem *reg;
  28        struct clk clk;
  29};
  30
  31static int octeontx_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
  32{
  33        struct octeontx_wdt *priv = dev_get_priv(dev);
  34        u64 clk_rate, val;
  35        u64 tout_wdog;
  36
  37        clk_rate = clk_get_rate(&priv->clk);
  38        if (IS_ERR_VALUE(clk_rate))
  39                return -EINVAL;
  40
  41        /* Watchdog counts in 1024 cycle steps */
  42        tout_wdog = (clk_rate * timeout_ms / 1000) >> 10;
  43
  44        /*
  45         * We can only specify the upper 16 bits of a 24 bit value.
  46         * Round up
  47         */
  48        tout_wdog = (tout_wdog + 0xff) >> 8;
  49
  50        /* If the timeout overflows the hardware limit, set max */
  51        if (tout_wdog >= 0x10000)
  52                tout_wdog = 0xffff;
  53
  54        val = FIELD_PREP(WDOG_MODE, 0x3) |
  55                FIELD_PREP(WDOG_LEN, tout_wdog) |
  56                FIELD_PREP(WDOG_CNT, tout_wdog << 8);
  57        writeq(val, priv->reg + CORE0_WDOG_OFFSET);
  58
  59        return 0;
  60}
  61
  62static int octeontx_wdt_stop(struct udevice *dev)
  63{
  64        struct octeontx_wdt *priv = dev_get_priv(dev);
  65
  66        writeq(0, priv->reg + CORE0_WDOG_OFFSET);
  67
  68        return 0;
  69}
  70
  71static int octeontx_wdt_expire_now(struct udevice *dev, ulong flags)
  72{
  73        octeontx_wdt_stop(dev);
  74
  75        /* Start with 100ms timeout to expire immediately */
  76        octeontx_wdt_start(dev, 100, flags);
  77
  78        return 0;
  79}
  80
  81static int octeontx_wdt_reset(struct udevice *dev)
  82{
  83        struct octeontx_wdt *priv = dev_get_priv(dev);
  84
  85        writeq(~0ULL, priv->reg + CORE0_POKE_OFFSET);
  86
  87        return 0;
  88}
  89
  90static int octeontx_wdt_remove(struct udevice *dev)
  91{
  92        octeontx_wdt_stop(dev);
  93
  94        return 0;
  95}
  96
  97static int octeontx_wdt_probe(struct udevice *dev)
  98{
  99        struct octeontx_wdt *priv = dev_get_priv(dev);
 100        int ret;
 101
 102        priv->reg = dev_remap_addr(dev);
 103        if (!priv->reg)
 104                return -EINVAL;
 105
 106        /*
 107         * Save base register address in reg masking lower 20 bits
 108         * as 0xa0000 appears when extracted from the DT
 109         */
 110        priv->reg = (void __iomem *)(((u64)priv->reg &
 111                                      ~CORE0_POKE_OFFSET_MASK));
 112
 113        ret = clk_get_by_index(dev, 0, &priv->clk);
 114        if (ret < 0)
 115                return ret;
 116
 117        ret = clk_enable(&priv->clk);
 118        if (ret)
 119                return ret;
 120
 121        return 0;
 122}
 123
 124static const struct wdt_ops octeontx_wdt_ops = {
 125        .reset = octeontx_wdt_reset,
 126        .start = octeontx_wdt_start,
 127        .stop = octeontx_wdt_stop,
 128        .expire_now = octeontx_wdt_expire_now,
 129};
 130
 131static const struct udevice_id octeontx_wdt_ids[] = {
 132        { .compatible = "arm,sbsa-gwdt" },
 133        {}
 134};
 135
 136U_BOOT_DRIVER(wdt_octeontx) = {
 137        .name = "wdt_octeontx",
 138        .id = UCLASS_WDT,
 139        .of_match = octeontx_wdt_ids,
 140        .ops = &octeontx_wdt_ops,
 141        .priv_auto      = sizeof(struct octeontx_wdt),
 142        .probe = octeontx_wdt_probe,
 143        .remove = octeontx_wdt_remove,
 144        .flags = DM_FLAG_OS_PREPARE,
 145};
 146