linux-stable/drivers/watchdog/davinci_wdt.c
Pratyush Anand 6551881c86 Watchdog: Fix parent of watchdog_devices
/sys/class/watchdog/watchdogn/device/modalias can help to identify the
driver/module for a given watchdog node. However, many wdt devices do not
set their parent and so, we do not see an entry for device in sysfs for
such devices.

This patch fixes parent of watchdog_device so that
/sys/class/watchdog/watchdogn/device is populated.

Exceptions: booke, diag288, octeon, softdog and w83627hf -- They do not
have any parent. Not sure, how we can identify driver for these devices.

Signed-off-by: Pratyush Anand <panand@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Maxime Coquelin <maxime.coquelin@st.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-09-09 21:39:22 +02:00

240 lines
6.3 KiB
C

/*
* drivers/char/watchdog/davinci_wdt.c
*
* Watchdog driver for DaVinci DM644x/DM646x processors
*
* Copyright (C) 2006-2013 Texas Instruments.
*
* 2007 (c) MontaVista Software, Inc. 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.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/device.h>
#include <linux/clk.h>
#include <linux/err.h>
#define MODULE_NAME "DAVINCI-WDT: "
#define DEFAULT_HEARTBEAT 60
#define MAX_HEARTBEAT 600 /* really the max margin is 264/27MHz*/
/* Timer register set definition */
#define PID12 (0x0)
#define EMUMGT (0x4)
#define TIM12 (0x10)
#define TIM34 (0x14)
#define PRD12 (0x18)
#define PRD34 (0x1C)
#define TCR (0x20)
#define TGCR (0x24)
#define WDTCR (0x28)
/* TCR bit definitions */
#define ENAMODE12_DISABLED (0 << 6)
#define ENAMODE12_ONESHOT (1 << 6)
#define ENAMODE12_PERIODIC (2 << 6)
/* TGCR bit definitions */
#define TIM12RS_UNRESET (1 << 0)
#define TIM34RS_UNRESET (1 << 1)
#define TIMMODE_64BIT_WDOG (2 << 2)
/* WDTCR bit definitions */
#define WDEN (1 << 14)
#define WDFLAG (1 << 15)
#define WDKEY_SEQ0 (0xa5c6 << 16)
#define WDKEY_SEQ1 (0xda7e << 16)
static int heartbeat;
/*
* struct to hold data for each WDT device
* @base - base io address of WD device
* @clk - source clock of WDT
* @wdd - hold watchdog device as is in WDT core
*/
struct davinci_wdt_device {
void __iomem *base;
struct clk *clk;
struct watchdog_device wdd;
};
static int davinci_wdt_start(struct watchdog_device *wdd)
{
u32 tgcr;
u32 timer_margin;
unsigned long wdt_freq;
struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
wdt_freq = clk_get_rate(davinci_wdt->clk);
/* disable, internal clock source */
iowrite32(0, davinci_wdt->base + TCR);
/* reset timer, set mode to 64-bit watchdog, and unreset */
iowrite32(0, davinci_wdt->base + TGCR);
tgcr = TIMMODE_64BIT_WDOG | TIM12RS_UNRESET | TIM34RS_UNRESET;
iowrite32(tgcr, davinci_wdt->base + TGCR);
/* clear counter regs */
iowrite32(0, davinci_wdt->base + TIM12);
iowrite32(0, davinci_wdt->base + TIM34);
/* set timeout period */
timer_margin = (((u64)wdd->timeout * wdt_freq) & 0xffffffff);
iowrite32(timer_margin, davinci_wdt->base + PRD12);
timer_margin = (((u64)wdd->timeout * wdt_freq) >> 32);
iowrite32(timer_margin, davinci_wdt->base + PRD34);
/* enable run continuously */
iowrite32(ENAMODE12_PERIODIC, davinci_wdt->base + TCR);
/* Once the WDT is in pre-active state write to
* TIM12, TIM34, PRD12, PRD34, TCR, TGCR, WDTCR are
* write protected (except for the WDKEY field)
*/
/* put watchdog in pre-active state */
iowrite32(WDKEY_SEQ0 | WDEN, davinci_wdt->base + WDTCR);
/* put watchdog in active state */
iowrite32(WDKEY_SEQ1 | WDEN, davinci_wdt->base + WDTCR);
return 0;
}
static int davinci_wdt_ping(struct watchdog_device *wdd)
{
struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
/* put watchdog in service state */
iowrite32(WDKEY_SEQ0, davinci_wdt->base + WDTCR);
/* put watchdog in active state */
iowrite32(WDKEY_SEQ1, davinci_wdt->base + WDTCR);
return 0;
}
static unsigned int davinci_wdt_get_timeleft(struct watchdog_device *wdd)
{
u64 timer_counter;
unsigned long freq;
u32 val;
struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
/* if timeout has occured then return 0 */
val = ioread32(davinci_wdt->base + WDTCR);
if (val & WDFLAG)
return 0;
freq = clk_get_rate(davinci_wdt->clk);
if (!freq)
return 0;
timer_counter = ioread32(davinci_wdt->base + TIM12);
timer_counter |= ((u64)ioread32(davinci_wdt->base + TIM34) << 32);
do_div(timer_counter, freq);
return wdd->timeout - timer_counter;
}
static const struct watchdog_info davinci_wdt_info = {
.options = WDIOF_KEEPALIVEPING,
.identity = "DaVinci/Keystone Watchdog",
};
static const struct watchdog_ops davinci_wdt_ops = {
.owner = THIS_MODULE,
.start = davinci_wdt_start,
.stop = davinci_wdt_ping,
.ping = davinci_wdt_ping,
.get_timeleft = davinci_wdt_get_timeleft,
};
static int davinci_wdt_probe(struct platform_device *pdev)
{
int ret = 0;
struct device *dev = &pdev->dev;
struct resource *wdt_mem;
struct watchdog_device *wdd;
struct davinci_wdt_device *davinci_wdt;
davinci_wdt = devm_kzalloc(dev, sizeof(*davinci_wdt), GFP_KERNEL);
if (!davinci_wdt)
return -ENOMEM;
davinci_wdt->clk = devm_clk_get(dev, NULL);
if (WARN_ON(IS_ERR(davinci_wdt->clk)))
return PTR_ERR(davinci_wdt->clk);
clk_prepare_enable(davinci_wdt->clk);
platform_set_drvdata(pdev, davinci_wdt);
wdd = &davinci_wdt->wdd;
wdd->info = &davinci_wdt_info;
wdd->ops = &davinci_wdt_ops;
wdd->min_timeout = 1;
wdd->max_timeout = MAX_HEARTBEAT;
wdd->timeout = DEFAULT_HEARTBEAT;
wdd->parent = &pdev->dev;
watchdog_init_timeout(wdd, heartbeat, dev);
dev_info(dev, "heartbeat %d sec\n", wdd->timeout);
watchdog_set_drvdata(wdd, davinci_wdt);
watchdog_set_nowayout(wdd, 1);
wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
davinci_wdt->base = devm_ioremap_resource(dev, wdt_mem);
if (IS_ERR(davinci_wdt->base))
return PTR_ERR(davinci_wdt->base);
ret = watchdog_register_device(wdd);
if (ret < 0)
dev_err(dev, "cannot register watchdog device\n");
return ret;
}
static int davinci_wdt_remove(struct platform_device *pdev)
{
struct davinci_wdt_device *davinci_wdt = platform_get_drvdata(pdev);
watchdog_unregister_device(&davinci_wdt->wdd);
clk_disable_unprepare(davinci_wdt->clk);
return 0;
}
static const struct of_device_id davinci_wdt_of_match[] = {
{ .compatible = "ti,davinci-wdt", },
{},
};
MODULE_DEVICE_TABLE(of, davinci_wdt_of_match);
static struct platform_driver platform_wdt_driver = {
.driver = {
.name = "davinci-wdt",
.of_match_table = davinci_wdt_of_match,
},
.probe = davinci_wdt_probe,
.remove = davinci_wdt_remove,
};
module_platform_driver(platform_wdt_driver);
MODULE_AUTHOR("Texas Instruments");
MODULE_DESCRIPTION("DaVinci 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_LICENSE("GPL");
MODULE_ALIAS("platform:davinci-wdt");