driver: watchdog: add sp805 watchdog support

sp805 is watchdog on some NXP layerscape SoCs, adding
it's driver. Configs CONFIG_WDT_SP805, CONFIG_WDT, CONFIG_CMD_WDT
needs to be enabled to use it.

Signed-off-by: Zhao Qiang <qiang.zhao@nxp.com>
Reviewed-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>
This commit is contained in:
Qiang Zhao 2019-05-07 03:16:09 +00:00 committed by Prabhakar Kushwaha
parent 49d88397e2
commit 0652d9fb1a
4 changed files with 136 additions and 0 deletions

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@ -519,6 +519,7 @@ FREESCALE QORIQ
M: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>
S: Maintained
T: git git://git.denx.de/u-boot-fsl-qoriq.git
F: drivers/watchdog/sp805_wdt.c
I2C
M: Heiko Schocher <hs@denx.de>

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@ -103,6 +103,13 @@ config WDT_ORION
Select this to enable Orion watchdog timer, which can be found on some
Marvell Armada chips.
config WDT_SP805
bool "SP805 watchdog timer support"
depends on WDT
help
Select this to enable SP805 watchdog timer, which can be found on some
nxp layerscape chips.
config WDT_CDNS
bool "Cadence watchdog timer support"
depends on WDT

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@ -27,3 +27,4 @@ obj-$(CONFIG_WDT_CDNS) += cdns_wdt.o
obj-$(CONFIG_WDT_MPC8xx) += mpc8xx_wdt.o
obj-$(CONFIG_WDT_MT7621) += mt7621_wdt.o
obj-$(CONFIG_WDT_MTK) += mtk_wdt.o
obj-$(CONFIG_WDT_SP805) += sp805_wdt.o

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@ -0,0 +1,127 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* Watchdog driver for SP805 on some Layerscape SoC
*
* Copyright 2019 NXP
*/
#include <asm/io.h>
#include <common.h>
#include <dm/device.h>
#include <dm/fdtaddr.h>
#include <dm/read.h>
#include <linux/bitops.h>
#include <watchdog.h>
#include <wdt.h>
#define WDTLOAD 0x000
#define WDTCONTROL 0x008
#define WDTINTCLR 0x00C
#define WDTLOCK 0xC00
#define TIME_OUT_MIN_MSECS 1
#define TIME_OUT_MAX_MSECS 120000
#define SYS_FSL_WDT_CLK_DIV 16
#define INT_ENABLE BIT(0)
#define RESET_ENABLE BIT(1)
#define DISABLE 0
#define UNLOCK 0x1ACCE551
#define LOCK 0x00000001
#define INT_MASK BIT(0)
DECLARE_GLOBAL_DATA_PTR;
struct sp805_wdt_priv {
void __iomem *reg;
};
static int sp805_wdt_reset(struct udevice *dev)
{
struct sp805_wdt_priv *priv = dev_get_priv(dev);
writel(UNLOCK, priv->reg + WDTLOCK);
writel(INT_MASK, priv->reg + WDTINTCLR);
writel(LOCK, priv->reg + WDTLOCK);
readl(priv->reg + WDTLOCK);
return 0;
}
static int sp805_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
{
u32 load_value;
u32 load_time;
struct sp805_wdt_priv *priv = dev_get_priv(dev);
load_time = (u32)timeout;
if (timeout < TIME_OUT_MIN_MSECS)
load_time = TIME_OUT_MIN_MSECS;
else if (timeout > TIME_OUT_MAX_MSECS)
load_time = TIME_OUT_MAX_MSECS;
/* sp805 runs counter with given value twice, so when the max timeout is
* set 120s, the gd->bus_clk is less than 1145MHz, the load_value will
* not overflow.
*/
load_value = (gd->bus_clk) /
(2 * 1000 * SYS_FSL_WDT_CLK_DIV) * load_time;
writel(UNLOCK, priv->reg + WDTLOCK);
writel(load_value, priv->reg + WDTLOAD);
writel(INT_MASK, priv->reg + WDTINTCLR);
writel(INT_ENABLE | RESET_ENABLE, priv->reg + WDTCONTROL);
writel(LOCK, priv->reg + WDTLOCK);
readl(priv->reg + WDTLOCK);
return 0;
}
static int sp805_wdt_stop(struct udevice *dev)
{
struct sp805_wdt_priv *priv = dev_get_priv(dev);
writel(UNLOCK, priv->reg + WDTLOCK);
writel(DISABLE, priv->reg + WDTCONTROL);
writel(LOCK, priv->reg + WDTLOCK);
readl(priv->reg + WDTLOCK);
return 0;
}
static int sp805_wdt_probe(struct udevice *dev)
{
debug("%s: Probing wdt%u\n", __func__, dev->seq);
return 0;
}
static int sp805_wdt_ofdata_to_platdata(struct udevice *dev)
{
struct sp805_wdt_priv *priv = dev_get_priv(dev);
priv->reg = (void __iomem *)dev_read_addr(dev);
if (IS_ERR(priv->reg))
return PTR_ERR(priv->reg);
return 0;
}
static const struct wdt_ops sp805_wdt_ops = {
.start = sp805_wdt_start,
.reset = sp805_wdt_reset,
.stop = sp805_wdt_stop,
};
static const struct udevice_id sp805_wdt_ids[] = {
{ .compatible = "arm,sp805-wdt" },
{}
};
U_BOOT_DRIVER(sp805_wdt) = {
.name = "sp805_wdt",
.id = UCLASS_WDT,
.of_match = sp805_wdt_ids,
.probe = sp805_wdt_probe,
.priv_auto_alloc_size = sizeof(struct sp805_wdt_priv),
.ofdata_to_platdata = sp805_wdt_ofdata_to_platdata,
.ops = &sp805_wdt_ops,
};