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watchdog: max63xx: dynamically allocate device
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This patch removes the static watchdog device for a new max63xx_wdt data
structure, and constifies the max63xx_timeout data.

The new structure contains pointers to pin access routines, which
abstracts mmap-specific code. This will ease future accesses like GPIO.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
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Vivien Didelot authored and Wim Van Sebroeck committed Jun 29, 2015
1 parent db11cba commit b9be966
Showing 1 changed file with 104 additions and 66 deletions.
170 changes: 104 additions & 66 deletions drivers/watchdog/max63xx_wdt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -39,10 +39,22 @@ static bool nowayout = WATCHDOG_NOWAYOUT;
#define MAX6369_WDSET (7 << 0)
#define MAX6369_WDI (1 << 3)

static DEFINE_SPINLOCK(io_lock);
#define MAX6369_WDSET_DISABLED 3

static int nodelay;
static void __iomem *wdt_base;

struct max63xx_wdt {
struct watchdog_device wdd;
const struct max63xx_timeout *timeout;

/* memory mapping */
void __iomem *base;
spinlock_t lock;

/* WDI and WSET bits write access routines */
void (*ping)(struct max63xx_wdt *wdt);
void (*set)(struct max63xx_wdt *wdt, u8 set);
};

/*
* The timeout values used are actually the absolute minimum the chip
Expand All @@ -59,25 +71,25 @@ static void __iomem *wdt_base;

/* Timeouts in second */
struct max63xx_timeout {
u8 wdset;
u8 tdelay;
u8 twd;
const u8 wdset;
const u8 tdelay;
const u8 twd;
};

static struct max63xx_timeout max6369_table[] = {
static const struct max63xx_timeout max6369_table[] = {
{ 5, 1, 1 },
{ 6, 10, 10 },
{ 7, 60, 60 },
{ },
};

static struct max63xx_timeout max6371_table[] = {
static const struct max63xx_timeout max6371_table[] = {
{ 6, 60, 3 },
{ 7, 60, 60 },
{ },
};

static struct max63xx_timeout max6373_table[] = {
static const struct max63xx_timeout max6373_table[] = {
{ 2, 60, 1 },
{ 5, 0, 1 },
{ 1, 3, 3 },
Expand All @@ -86,8 +98,6 @@ static struct max63xx_timeout max6373_table[] = {
{ },
};

static struct max63xx_timeout *current_timeout;

static struct max63xx_timeout *
max63xx_select_timeout(struct max63xx_timeout *table, int value)
{
Expand All @@ -108,109 +118,137 @@ max63xx_select_timeout(struct max63xx_timeout *table, int value)

static int max63xx_wdt_ping(struct watchdog_device *wdd)
{
u8 val;

spin_lock(&io_lock);
struct max63xx_wdt *wdt = watchdog_get_drvdata(wdd);

val = __raw_readb(wdt_base);

__raw_writeb(val | MAX6369_WDI, wdt_base);
__raw_writeb(val & ~MAX6369_WDI, wdt_base);

spin_unlock(&io_lock);
wdt->ping(wdt);
return 0;
}

static int max63xx_wdt_start(struct watchdog_device *wdd)
{
struct max63xx_timeout *entry = watchdog_get_drvdata(wdd);
u8 val;
struct max63xx_wdt *wdt = watchdog_get_drvdata(wdd);

spin_lock(&io_lock);

val = __raw_readb(wdt_base);
val &= ~MAX6369_WDSET;
val |= entry->wdset;
__raw_writeb(val, wdt_base);

spin_unlock(&io_lock);
wdt->set(wdt, wdt->timeout->wdset);

/* check for a edge triggered startup */
if (entry->tdelay == 0)
max63xx_wdt_ping(wdd);
if (wdt->timeout->tdelay == 0)
wdt->ping(wdt);
return 0;
}

static int max63xx_wdt_stop(struct watchdog_device *wdd)
{
u8 val;
struct max63xx_wdt *wdt = watchdog_get_drvdata(wdd);

spin_lock(&io_lock);

val = __raw_readb(wdt_base);
val &= ~MAX6369_WDSET;
val |= 3;
__raw_writeb(val, wdt_base);

spin_unlock(&io_lock);
wdt->set(wdt, MAX6369_WDSET_DISABLED);
return 0;
}

static const struct watchdog_info max63xx_wdt_info = {
.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "max63xx Watchdog",
};

static const struct watchdog_ops max63xx_wdt_ops = {
.owner = THIS_MODULE,
.start = max63xx_wdt_start,
.stop = max63xx_wdt_stop,
.ping = max63xx_wdt_ping,
};

static struct watchdog_device max63xx_wdt_dev = {
.info = &max63xx_wdt_info,
.ops = &max63xx_wdt_ops,
static const struct watchdog_info max63xx_wdt_info = {
.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "max63xx Watchdog",
};

static void max63xx_mmap_ping(struct max63xx_wdt *wdt)
{
u8 val;

spin_lock(&wdt->lock);

val = __raw_readb(wdt->base);

__raw_writeb(val | MAX6369_WDI, wdt->base);
__raw_writeb(val & ~MAX6369_WDI, wdt->base);

spin_unlock(&wdt->lock);
}

static void max63xx_mmap_set(struct max63xx_wdt *wdt, u8 set)
{
u8 val;

spin_lock(&wdt->lock);

val = __raw_readb(wdt->base);
val &= ~MAX6369_WDSET;
val |= set & MAX6369_WDSET;
__raw_writeb(val, wdt->base);

spin_unlock(&wdt->lock);
}

static int max63xx_mmap_init(struct platform_device *p, struct max63xx_wdt *wdt)
{
struct resource *mem = platform_get_resource(p, IORESOURCE_MEM, 0);

wdt->base = devm_ioremap_resource(&p->dev, mem);
if (IS_ERR(wdt->base))
return PTR_ERR(wdt->base);

spin_lock_init(&wdt->lock);

wdt->ping = max63xx_mmap_ping;
wdt->set = max63xx_mmap_set;
return 0;
}

static int max63xx_wdt_probe(struct platform_device *pdev)
{
struct resource *wdt_mem;
struct max63xx_wdt *wdt;
struct max63xx_timeout *table;
int err;

wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;

table = (struct max63xx_timeout *)pdev->id_entry->driver_data;

if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
heartbeat = DEFAULT_HEARTBEAT;

dev_info(&pdev->dev, "requesting %ds heartbeat\n", heartbeat);
current_timeout = max63xx_select_timeout(table, heartbeat);

if (!current_timeout) {
dev_err(&pdev->dev, "unable to satisfy heartbeat request\n");
wdt->timeout = max63xx_select_timeout(table, heartbeat);
if (!wdt->timeout) {
dev_err(&pdev->dev, "unable to satisfy %ds heartbeat request\n",
heartbeat);
return -EINVAL;
}

dev_info(&pdev->dev, "using %ds heartbeat with %ds initial delay\n",
current_timeout->twd, current_timeout->tdelay);
err = max63xx_mmap_init(pdev, wdt);
if (err)
return err;

platform_set_drvdata(pdev, &wdt->wdd);
watchdog_set_drvdata(&wdt->wdd, wdt);

heartbeat = current_timeout->twd;
wdt->wdd.parent = &pdev->dev;
wdt->wdd.timeout = wdt->timeout->twd;
wdt->wdd.info = &max63xx_wdt_info;
wdt->wdd.ops = &max63xx_wdt_ops;

wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
wdt_base = devm_ioremap_resource(&pdev->dev, wdt_mem);
if (IS_ERR(wdt_base))
return PTR_ERR(wdt_base);
watchdog_set_nowayout(&wdt->wdd, nowayout);

max63xx_wdt_dev.timeout = heartbeat;
watchdog_set_nowayout(&max63xx_wdt_dev, nowayout);
watchdog_set_drvdata(&max63xx_wdt_dev, current_timeout);
err = watchdog_register_device(&wdt->wdd);
if (err)
return err;

return watchdog_register_device(&max63xx_wdt_dev);
dev_info(&pdev->dev, "using %ds heartbeat with %ds initial delay\n",
wdt->timeout->twd, wdt->timeout->tdelay);
return 0;
}

static int max63xx_wdt_remove(struct platform_device *pdev)
{
watchdog_unregister_device(&max63xx_wdt_dev);
struct watchdog_device *wdd = platform_get_drvdata(pdev);

watchdog_unregister_device(wdd);
return 0;
}

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