forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
286 lines
6.8 KiB
286 lines
6.8 KiB
/* |
|
* drivers/char/watchdog/max63xx_wdt.c |
|
* |
|
* Driver for max63{69,70,71,72,73,74} watchdog timers |
|
* |
|
* Copyright (C) 2009 Marc Zyngier <[email protected]> |
|
* |
|
* This file is licensed under the terms of the GNU General Public |
|
* License version 2. This program is licensed "as is" without any |
|
* warranty of any kind, whether express or implied. |
|
* |
|
* This driver assumes the watchdog pins are memory mapped (as it is |
|
* the case for the Arcom Zeus). Should it be connected over GPIOs or |
|
* another interface, some abstraction will have to be introduced. |
|
*/ |
|
|
|
#include <linux/err.h> |
|
#include <linux/module.h> |
|
#include <linux/moduleparam.h> |
|
#include <linux/mod_devicetable.h> |
|
#include <linux/types.h> |
|
#include <linux/kernel.h> |
|
#include <linux/watchdog.h> |
|
#include <linux/bitops.h> |
|
#include <linux/platform_device.h> |
|
#include <linux/spinlock.h> |
|
#include <linux/io.h> |
|
#include <linux/slab.h> |
|
|
|
#define DEFAULT_HEARTBEAT 60 |
|
#define MAX_HEARTBEAT 60 |
|
|
|
static unsigned int heartbeat = DEFAULT_HEARTBEAT; |
|
static bool nowayout = WATCHDOG_NOWAYOUT; |
|
|
|
/* |
|
* Memory mapping: a single byte, 3 first lower bits to select bit 3 |
|
* to ping the watchdog. |
|
*/ |
|
#define MAX6369_WDSET (7 << 0) |
|
#define MAX6369_WDI (1 << 3) |
|
|
|
#define MAX6369_WDSET_DISABLED 3 |
|
|
|
static int nodelay; |
|
|
|
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 |
|
* offers. Typical values on my board are slightly over twice as long |
|
* (10s setting ends up with a 25s timeout), and can be up to 3 times |
|
* the nominal setting (according to the datasheet). So please take |
|
* these values with a grain of salt. Same goes for the initial delay |
|
* "feature". Only max6373/74 have a few settings without this initial |
|
* delay (selected with the "nodelay" parameter). |
|
* |
|
* I also decided to remove from the tables any timeout smaller than a |
|
* second, as it looked completly overkill... |
|
*/ |
|
|
|
/* Timeouts in second */ |
|
struct max63xx_timeout { |
|
const u8 wdset; |
|
const u8 tdelay; |
|
const u8 twd; |
|
}; |
|
|
|
static const struct max63xx_timeout max6369_table[] = { |
|
{ 5, 1, 1 }, |
|
{ 6, 10, 10 }, |
|
{ 7, 60, 60 }, |
|
{ }, |
|
}; |
|
|
|
static const struct max63xx_timeout max6371_table[] = { |
|
{ 6, 60, 3 }, |
|
{ 7, 60, 60 }, |
|
{ }, |
|
}; |
|
|
|
static const struct max63xx_timeout max6373_table[] = { |
|
{ 2, 60, 1 }, |
|
{ 5, 0, 1 }, |
|
{ 1, 3, 3 }, |
|
{ 7, 60, 10 }, |
|
{ 6, 0, 10 }, |
|
{ }, |
|
}; |
|
|
|
static struct max63xx_timeout * |
|
max63xx_select_timeout(struct max63xx_timeout *table, int value) |
|
{ |
|
while (table->twd) { |
|
if (value <= table->twd) { |
|
if (nodelay && table->tdelay == 0) |
|
return table; |
|
|
|
if (!nodelay) |
|
return table; |
|
} |
|
|
|
table++; |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
static int max63xx_wdt_ping(struct watchdog_device *wdd) |
|
{ |
|
struct max63xx_wdt *wdt = watchdog_get_drvdata(wdd); |
|
|
|
wdt->ping(wdt); |
|
return 0; |
|
} |
|
|
|
static int max63xx_wdt_start(struct watchdog_device *wdd) |
|
{ |
|
struct max63xx_wdt *wdt = watchdog_get_drvdata(wdd); |
|
|
|
wdt->set(wdt, wdt->timeout->wdset); |
|
|
|
/* check for a edge triggered startup */ |
|
if (wdt->timeout->tdelay == 0) |
|
wdt->ping(wdt); |
|
return 0; |
|
} |
|
|
|
static int max63xx_wdt_stop(struct watchdog_device *wdd) |
|
{ |
|
struct max63xx_wdt *wdt = watchdog_get_drvdata(wdd); |
|
|
|
wdt->set(wdt, MAX6369_WDSET_DISABLED); |
|
return 0; |
|
} |
|
|
|
static const struct watchdog_ops max63xx_wdt_ops = { |
|
.owner = THIS_MODULE, |
|
.start = max63xx_wdt_start, |
|
.stop = max63xx_wdt_stop, |
|
.ping = max63xx_wdt_ping, |
|
}; |
|
|
|
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) |
|
{ |
|
wdt->base = devm_platform_ioremap_resource(p, 0); |
|
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 device *dev = &pdev->dev; |
|
struct max63xx_wdt *wdt; |
|
struct max63xx_timeout *table; |
|
int err; |
|
|
|
wdt = devm_kzalloc(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; |
|
|
|
wdt->timeout = max63xx_select_timeout(table, heartbeat); |
|
if (!wdt->timeout) { |
|
dev_err(dev, "unable to satisfy %ds heartbeat request\n", |
|
heartbeat); |
|
return -EINVAL; |
|
} |
|
|
|
err = max63xx_mmap_init(pdev, wdt); |
|
if (err) |
|
return err; |
|
|
|
platform_set_drvdata(pdev, &wdt->wdd); |
|
watchdog_set_drvdata(&wdt->wdd, wdt); |
|
|
|
wdt->wdd.parent = dev; |
|
wdt->wdd.timeout = wdt->timeout->twd; |
|
wdt->wdd.info = &max63xx_wdt_info; |
|
wdt->wdd.ops = &max63xx_wdt_ops; |
|
|
|
watchdog_set_nowayout(&wdt->wdd, nowayout); |
|
|
|
err = devm_watchdog_register_device(dev, &wdt->wdd); |
|
if (err) |
|
return err; |
|
|
|
dev_info(dev, "using %ds heartbeat with %ds initial delay\n", |
|
wdt->timeout->twd, wdt->timeout->tdelay); |
|
return 0; |
|
} |
|
|
|
static const struct platform_device_id max63xx_id_table[] = { |
|
{ "max6369_wdt", (kernel_ulong_t)max6369_table, }, |
|
{ "max6370_wdt", (kernel_ulong_t)max6369_table, }, |
|
{ "max6371_wdt", (kernel_ulong_t)max6371_table, }, |
|
{ "max6372_wdt", (kernel_ulong_t)max6371_table, }, |
|
{ "max6373_wdt", (kernel_ulong_t)max6373_table, }, |
|
{ "max6374_wdt", (kernel_ulong_t)max6373_table, }, |
|
{ }, |
|
}; |
|
MODULE_DEVICE_TABLE(platform, max63xx_id_table); |
|
|
|
static struct platform_driver max63xx_wdt_driver = { |
|
.probe = max63xx_wdt_probe, |
|
.id_table = max63xx_id_table, |
|
.driver = { |
|
.name = "max63xx_wdt", |
|
}, |
|
}; |
|
|
|
module_platform_driver(max63xx_wdt_driver); |
|
|
|
MODULE_AUTHOR("Marc Zyngier <[email protected]>"); |
|
MODULE_DESCRIPTION("max63xx Watchdog Driver"); |
|
|
|
module_param(heartbeat, int, 0); |
|
MODULE_PARM_DESC(heartbeat, |
|
"Watchdog heartbeat period in seconds from 1 to " |
|
__MODULE_STRING(MAX_HEARTBEAT) ", default " |
|
__MODULE_STRING(DEFAULT_HEARTBEAT)); |
|
|
|
module_param(nowayout, bool, 0); |
|
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
|
|
|
module_param(nodelay, int, 0); |
|
MODULE_PARM_DESC(nodelay, |
|
"Force selection of a timeout setting without initial delay " |
|
"(max6373/74 only, default=0)"); |
|
|
|
MODULE_LICENSE("GPL v2");
|
|
|