OpenCloudOS-Kernel/drivers/watchdog/asm9260_wdt.c

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/*
* Watchdog driver for Alphascale ASM9260.
*
* Copyright (c) 2014 Oleksij Rempel <linux@rempel-privat.de>
*
* Licensed under GPLv2 or later.
*/
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/watchdog.h>
#define CLOCK_FREQ 1000000
/* Watchdog Mode register */
#define HW_WDMOD 0x00
/* Wake interrupt. Set by HW, can't be cleared. */
#define BM_MOD_WDINT BIT(3)
/* This bit set if timeout reached. Cleared by SW. */
#define BM_MOD_WDTOF BIT(2)
/* HW Reset on timeout */
#define BM_MOD_WDRESET BIT(1)
/* WD enable */
#define BM_MOD_WDEN BIT(0)
/*
* Watchdog Timer Constant register
* Minimal value is 0xff, the meaning of this value
* depends on used clock: T = WDCLK * (0xff + 1) * 4
*/
#define HW_WDTC 0x04
#define BM_WDTC_MAX(freq) (0x7fffffff / (freq))
/* Watchdog Feed register */
#define HW_WDFEED 0x08
/* Watchdog Timer Value register */
#define HW_WDTV 0x0c
#define ASM9260_WDT_DEFAULT_TIMEOUT 30
enum asm9260_wdt_mode {
HW_RESET,
SW_RESET,
DEBUG,
};
struct asm9260_wdt_priv {
struct device *dev;
struct watchdog_device wdd;
struct clk *clk;
struct clk *clk_ahb;
struct reset_control *rst;
void __iomem *iobase;
int irq;
unsigned long wdt_freq;
enum asm9260_wdt_mode mode;
};
static int asm9260_wdt_feed(struct watchdog_device *wdd)
{
struct asm9260_wdt_priv *priv = watchdog_get_drvdata(wdd);
iowrite32(0xaa, priv->iobase + HW_WDFEED);
iowrite32(0x55, priv->iobase + HW_WDFEED);
return 0;
}
static unsigned int asm9260_wdt_gettimeleft(struct watchdog_device *wdd)
{
struct asm9260_wdt_priv *priv = watchdog_get_drvdata(wdd);
u32 counter;
counter = ioread32(priv->iobase + HW_WDTV);
return DIV_ROUND_CLOSEST(counter, priv->wdt_freq);
}
static int asm9260_wdt_updatetimeout(struct watchdog_device *wdd)
{
struct asm9260_wdt_priv *priv = watchdog_get_drvdata(wdd);
u32 counter;
counter = wdd->timeout * priv->wdt_freq;
iowrite32(counter, priv->iobase + HW_WDTC);
return 0;
}
static int asm9260_wdt_enable(struct watchdog_device *wdd)
{
struct asm9260_wdt_priv *priv = watchdog_get_drvdata(wdd);
u32 mode = 0;
if (priv->mode == HW_RESET)
mode = BM_MOD_WDRESET;
iowrite32(BM_MOD_WDEN | mode, priv->iobase + HW_WDMOD);
asm9260_wdt_updatetimeout(wdd);
asm9260_wdt_feed(wdd);
return 0;
}
static int asm9260_wdt_disable(struct watchdog_device *wdd)
{
struct asm9260_wdt_priv *priv = watchdog_get_drvdata(wdd);
/* The only way to disable WD is to reset it. */
reset_control_assert(priv->rst);
reset_control_deassert(priv->rst);
return 0;
}
static int asm9260_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)
{
wdd->timeout = to;
asm9260_wdt_updatetimeout(wdd);
return 0;
}
static void asm9260_wdt_sys_reset(struct asm9260_wdt_priv *priv)
{
/* init WD if it was not started */
iowrite32(BM_MOD_WDEN | BM_MOD_WDRESET, priv->iobase + HW_WDMOD);
iowrite32(0xff, priv->iobase + HW_WDTC);
/* first pass correct sequence */
asm9260_wdt_feed(&priv->wdd);
/*
* Then write wrong pattern to the feed to trigger reset
* ASAP.
*/
iowrite32(0xff, priv->iobase + HW_WDFEED);
mdelay(1000);
}
static irqreturn_t asm9260_wdt_irq(int irq, void *devid)
{
struct asm9260_wdt_priv *priv = devid;
u32 stat;
stat = ioread32(priv->iobase + HW_WDMOD);
if (!(stat & BM_MOD_WDINT))
return IRQ_NONE;
if (priv->mode == DEBUG) {
dev_info(priv->dev, "Watchdog Timeout. Do nothing.\n");
} else {
dev_info(priv->dev, "Watchdog Timeout. Doing SW Reset.\n");
asm9260_wdt_sys_reset(priv);
}
return IRQ_HANDLED;
}
static int asm9260_restart(struct watchdog_device *wdd, unsigned long action,
void *data)
{
struct asm9260_wdt_priv *priv = watchdog_get_drvdata(wdd);
asm9260_wdt_sys_reset(priv);
return 0;
}
static const struct watchdog_info asm9260_wdt_ident = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING
| WDIOF_MAGICCLOSE,
.identity = "Alphascale asm9260 Watchdog",
};
watchdog: constify watchdog_ops structures Declare watchdog_ops structures as const as they are only stored in the ops field of a watchdog_device structure. This field is of type const, so watchdog_ops structures having this property can be made const too. Done using Coccinelle: @r disable optional_qualifier@ identifier x; position p; @@ static struct watchdog_ops x@p={...}; @ok@ struct watchdog_device w; identifier r.x; position p; @@ w.ops=&x@p; @bad@ position p != {r.p,ok.p}; identifier r.x; @@ x@p @depends on !bad disable optional_qualifier@ identifier r.x; @@ +const struct watchdog_ops x; File size details before and after patching. First line of every .o file shows the file size before patching and second line shows the size after patching. text data bss dec hex filename 1340 544 0 1884 75c drivers/watchdog/bcm_kona_wdt.o 1436 440 0 1876 754 drivers/watchdog/bcm_kona_wdt.o 1176 544 4 1724 6bc drivers/watchdog/digicolor_wdt.o 1272 440 4 1716 6b4 drivers/watchdog/digicolor_wdt.o 925 580 89 1594 63a drivers/watchdog/ep93xx_wdt.o 1021 476 89 1586 632 drivers/watchdog/ep93xx_wdt.o 4932 288 17 5237 1475 drivers/watchdog/s3c2410_wdt.o 5028 192 17 5237 1475 drivers/watchdog/s3c2410_wdt.o 1977 292 1 2270 8de drivers/watchdog/sama5d4_wdt.o 2073 196 1 2270 8de drivers/watchdog/sama5d4_wdt.o 1375 484 1 1860 744 drivers/watchdog/sirfsoc_wdt.o 1471 380 1 1852 73c drivers/watchdog/sirfsoc_wdt.o Size remains the same for the files drivers/watchdog/diag288_wdt.o drivers/watchdog/asm9260_wdt.o and drivers/watchdog/atlas7_wdt.o The following .o files did not compile: drivers/watchdog/sun4v_wdt.o, drivers/watchdog/sbsa_gwdt.o, drivers/watchdog/rt2880_wdt.o, drivers/watchdog/booke_wdt.o drivers/watchdog/mt7621_wdt.o Signed-off-by: Bhumika Goyal <bhumirks@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2017-01-28 15:41:17 +08:00
static const struct watchdog_ops asm9260_wdt_ops = {
.owner = THIS_MODULE,
.start = asm9260_wdt_enable,
.stop = asm9260_wdt_disable,
.get_timeleft = asm9260_wdt_gettimeleft,
.ping = asm9260_wdt_feed,
.set_timeout = asm9260_wdt_settimeout,
.restart = asm9260_restart,
};
static int asm9260_wdt_get_dt_clks(struct asm9260_wdt_priv *priv)
{
int err;
unsigned long clk;
priv->clk = devm_clk_get(priv->dev, "mod");
if (IS_ERR(priv->clk)) {
dev_err(priv->dev, "Failed to get \"mod\" clk\n");
return PTR_ERR(priv->clk);
}
/* configure AHB clock */
priv->clk_ahb = devm_clk_get(priv->dev, "ahb");
if (IS_ERR(priv->clk_ahb)) {
dev_err(priv->dev, "Failed to get \"ahb\" clk\n");
return PTR_ERR(priv->clk_ahb);
}
err = clk_prepare_enable(priv->clk_ahb);
if (err) {
dev_err(priv->dev, "Failed to enable ahb_clk!\n");
return err;
}
err = clk_set_rate(priv->clk, CLOCK_FREQ);
if (err) {
clk_disable_unprepare(priv->clk_ahb);
dev_err(priv->dev, "Failed to set rate!\n");
return err;
}
err = clk_prepare_enable(priv->clk);
if (err) {
clk_disable_unprepare(priv->clk_ahb);
dev_err(priv->dev, "Failed to enable clk!\n");
return err;
}
/* wdt has internal divider */
clk = clk_get_rate(priv->clk);
if (!clk) {
clk_disable_unprepare(priv->clk);
clk_disable_unprepare(priv->clk_ahb);
dev_err(priv->dev, "Failed, clk is 0!\n");
return -EINVAL;
}
priv->wdt_freq = clk / 2;
return 0;
}
static void asm9260_wdt_get_dt_mode(struct asm9260_wdt_priv *priv)
{
const char *tmp;
int ret;
/* default mode */
priv->mode = HW_RESET;
ret = of_property_read_string(priv->dev->of_node,
"alphascale,mode", &tmp);
if (ret < 0)
return;
if (!strcmp(tmp, "hw"))
priv->mode = HW_RESET;
else if (!strcmp(tmp, "sw"))
priv->mode = SW_RESET;
else if (!strcmp(tmp, "debug"))
priv->mode = DEBUG;
else
dev_warn(priv->dev, "unknown reset-type: %s. Using default \"hw\" mode.",
tmp);
}
static int asm9260_wdt_probe(struct platform_device *pdev)
{
struct asm9260_wdt_priv *priv;
struct watchdog_device *wdd;
struct resource *res;
int ret;
const char * const mode_name[] = { "hw", "sw", "debug", };
priv = devm_kzalloc(&pdev->dev, sizeof(struct asm9260_wdt_priv),
GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->dev = &pdev->dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->iobase = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(priv->iobase))
return PTR_ERR(priv->iobase);
ret = asm9260_wdt_get_dt_clks(priv);
if (ret)
return ret;
priv->rst = devm_reset_control_get(&pdev->dev, "wdt_rst");
if (IS_ERR(priv->rst))
return PTR_ERR(priv->rst);
wdd = &priv->wdd;
wdd->info = &asm9260_wdt_ident;
wdd->ops = &asm9260_wdt_ops;
wdd->min_timeout = 1;
wdd->max_timeout = BM_WDTC_MAX(priv->wdt_freq);
wdd->parent = &pdev->dev;
watchdog_set_drvdata(wdd, priv);
/*
* If 'timeout-sec' unspecified in devicetree, assume a 30 second
* default, unless the max timeout is less than 30 seconds, then use
* the max instead.
*/
wdd->timeout = ASM9260_WDT_DEFAULT_TIMEOUT;
watchdog_init_timeout(wdd, 0, &pdev->dev);
asm9260_wdt_get_dt_mode(priv);
if (priv->mode != HW_RESET)
priv->irq = platform_get_irq(pdev, 0);
if (priv->irq > 0) {
/*
* Not all supported platforms specify an interrupt for the
* watchdog, so let's make it optional.
*/
ret = devm_request_irq(&pdev->dev, priv->irq,
asm9260_wdt_irq, 0, pdev->name, priv);
if (ret < 0)
dev_warn(&pdev->dev, "failed to request IRQ\n");
}
watchdog_set_restart_priority(wdd, 128);
ret = watchdog_register_device(wdd);
if (ret)
goto clk_off;
platform_set_drvdata(pdev, priv);
dev_info(&pdev->dev, "Watchdog enabled (timeout: %d sec, mode: %s)\n",
wdd->timeout, mode_name[priv->mode]);
return 0;
clk_off:
clk_disable_unprepare(priv->clk);
clk_disable_unprepare(priv->clk_ahb);
return ret;
}
static void asm9260_wdt_shutdown(struct platform_device *pdev)
{
struct asm9260_wdt_priv *priv = platform_get_drvdata(pdev);
asm9260_wdt_disable(&priv->wdd);
}
static int asm9260_wdt_remove(struct platform_device *pdev)
{
struct asm9260_wdt_priv *priv = platform_get_drvdata(pdev);
asm9260_wdt_disable(&priv->wdd);
watchdog_unregister_device(&priv->wdd);
clk_disable_unprepare(priv->clk);
clk_disable_unprepare(priv->clk_ahb);
return 0;
}
static const struct of_device_id asm9260_wdt_of_match[] = {
{ .compatible = "alphascale,asm9260-wdt"},
{},
};
MODULE_DEVICE_TABLE(of, asm9260_wdt_of_match);
static struct platform_driver asm9260_wdt_driver = {
.driver = {
.name = "asm9260-wdt",
.of_match_table = asm9260_wdt_of_match,
},
.probe = asm9260_wdt_probe,
.remove = asm9260_wdt_remove,
.shutdown = asm9260_wdt_shutdown,
};
module_platform_driver(asm9260_wdt_driver);
MODULE_DESCRIPTION("asm9260 WatchDog Timer Driver");
MODULE_AUTHOR("Oleksij Rempel <linux@rempel-privat.de>");
MODULE_LICENSE("GPL");