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watchdog: MIPS: lantiq: implement OF support and minor fixes

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Add support for OF. We also apply the following small fixes
* reduce boiler plate by using devm_request_and_ioremap
* sane error path for the clock
* move LTQ_RST_CAUSE_WDTRST to a soc specific header file
* add a message to show that the driver loaded

Signed-off-by: John Crispin <blogic@openwrt.org>
Acked-by: Wim Van Sebroeck <wim@iguana.be>
Cc: linux-watchdog@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3810/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
John Crispin 2012-04-12 21:21:56 +02:00 committed by Ralf Baechle
parent ceff2676b0
commit cdb8612147
3 changed files with 27 additions and 32 deletions
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1
arch/mips/include/asm/mach-lantiq/lantiq.h
View File

@ -49,7 +49,6 @@ extern struct clk *clk_get_io(void);
extern unsigned char ltq_boot_select(void);
/* find out what caused the last cpu reset */
extern int ltq_reset_cause(void);
#define LTQ_RST_CAUSE_WDTRST 0x20
#define IOPORT_RESOURCE_START 0x10000000
#define IOPORT_RESOURCE_END 0xffffffff

2
arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h
View File

@ -133,6 +133,8 @@ extern __iomem void *ltq_cgu_membase;
#define LTQ_WDT_BASE_ADDR 0x1F8803F0
#define LTQ_WDT_SIZE 0x10
#define LTQ_RST_CAUSE_WDTRST 0x20
/* STP - serial to parallel conversion unit */
#define LTQ_STP_BASE_ADDR 0x1E100BB0
#define LTQ_STP_SIZE 0x40

56
drivers/watchdog/lantiq_wdt.c
View File

@ -13,14 +13,15 @@
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/of_platform.h>
#include <linux/uaccess.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <lantiq.h>
#include <lantiq_soc.h>
/* Section 3.4 of the datasheet
/*
* Section 3.4 of the datasheet
* The password sequence protects the WDT control register from unintended
* write actions, which might cause malfunction of the WDT.
*
@ -70,7 +71,8 @@ ltq_wdt_disable(void)
{
/* write the first password magic */
ltq_w32(LTQ_WDT_PW1, ltq_wdt_membase + LTQ_WDT_CR);
/* write the second password magic with no config
/*
* write the second password magic with no config
* this turns the watchdog off
*/
ltq_w32(LTQ_WDT_PW2, ltq_wdt_membase + LTQ_WDT_CR);
@ -184,7 +186,7 @@ static struct miscdevice ltq_wdt_miscdev = {
.fops = &ltq_wdt_fops,
};
static int __init
static int __devinit
ltq_wdt_probe(struct platform_device *pdev)
{
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@ -194,28 +196,27 @@ ltq_wdt_probe(struct platform_device *pdev)
dev_err(&pdev->dev, "cannot obtain I/O memory region");
return -ENOENT;
}
res = devm_request_mem_region(&pdev->dev, res->start,
resource_size(res), dev_name(&pdev->dev));
if (!res) {
dev_err(&pdev->dev, "cannot request I/O memory region");
return -EBUSY;
}
ltq_wdt_membase = devm_ioremap_nocache(&pdev->dev, res->start,
resource_size(res));
ltq_wdt_membase = devm_request_and_ioremap(&pdev->dev, res);
if (!ltq_wdt_membase) {
dev_err(&pdev->dev, "cannot remap I/O memory region\n");
return -ENOMEM;
}
/* we do not need to enable the clock as it is always running */
clk = clk_get(&pdev->dev, "io");
WARN_ON(!clk);
clk = clk_get_io();
if (IS_ERR(clk)) {
dev_err(&pdev->dev, "Failed to get clock\n");
return -ENOENT;
}
ltq_io_region_clk_rate = clk_get_rate(clk);
clk_put(clk);
/* find out if the watchdog caused the last reboot */
if (ltq_reset_cause() == LTQ_RST_CAUSE_WDTRST)
ltq_wdt_bootstatus = WDIOF_CARDRESET;
dev_info(&pdev->dev, "Init done\n");
return misc_register(&ltq_wdt_miscdev);
}
@ -227,33 +228,26 @@ ltq_wdt_remove(struct platform_device *pdev)
return 0;
}
static const struct of_device_id ltq_wdt_match[] = {
{ .compatible = "lantiq,wdt" },
{},
};
MODULE_DEVICE_TABLE(of, ltq_wdt_match);
static struct platform_driver ltq_wdt_driver = {
.probe = ltq_wdt_probe,
.remove = __devexit_p(ltq_wdt_remove),
.driver = {
.name = "ltq_wdt",
.name = "wdt",
.owner = THIS_MODULE,
.of_match_table = ltq_wdt_match,
},
};
static int __init
init_ltq_wdt(void)
{
return platform_driver_probe(&ltq_wdt_driver, ltq_wdt_probe);
}
static void __exit
exit_ltq_wdt(void)
{
return platform_driver_unregister(&ltq_wdt_driver);
}
module_init(init_ltq_wdt);
module_exit(exit_ltq_wdt);
module_platform_driver(ltq_wdt_driver);
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
MODULE_DESCRIPTION("Lantiq SoC Watchdog");
MODULE_LICENSE("GPL");