Re: [PATCH] watchdog: at91rm9200: allow building when using device tree

Arnd Bergmann
2014-10-30T15:43:52Z

On Thursday 30 October 2014 16:17:19 Alexandre Belloni wrote:
>
> On 30/10/2014 at 15:43:43 +0100, Arnd Bergmann wrote :
> > On Thursday 30 October 2014 15:36:24 Boris Brezillon wrote:
> > > On Thu, 30 Oct 2014 15:15:34 +0100
> > > Alexandre Belloni <alexandre.belloni@free-electrons.com> wrote:
> > >
> > > > When building with device tree, ARCH_AT91RM9200 may not be selected. Allow
> > > > building that driver by also depending on ARCH_AT91.
> > > >
> > > > Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> > >
> > > Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> > >
> >
> > Doesn't this reintroduce the bug fixed by commit 09549cd0172 ("watchdog:
> > Revert the AT91RM9200_WATCHDOG dependency")?
> >
> > At least in 3.18-rc2, the driver still uses at91_st_write/at91_st_read.
> >
>
> Hum, right, then we have no better way to express that than depends on
> SOC_AT91RM9200, would that be acceptable ?
>

Sounds fine to me, but why can't we just fix the dependency?

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/arch/arm/mach-at91/at91rm9200_devices.c b/arch/arm/mach-at91/at91rm9200_devices.c
index 74f1eaf97801..7f51e406b240 100644
--- a/arch/arm/mach-at91/at91rm9200_devices.c
+++ b/arch/arm/mach-at91/at91rm9200_devices.c
@@ -719,10 +719,19 @@ static void __init at91_add_device_rtc(void) {}
* -------------------------------------------------------------------- */

#if defined(CONFIG_AT91RM9200_WATCHDOG) || defined(CONFIG_AT91RM9200_WATCHDOG_MODULE)
+static struct resource wdt_resources[] = {
+ [0] = {
+ .start = AT91RM9200_BASE_ST,
+ .end = AT91RM9200_BASE_ST + SZ_256 - 1,
+ .flags = IORESOURCE_MEM,
+ };
+};
+
static struct platform_device at91rm9200_wdt_device = {
- .name = "at91_wdt",
+ .name = "at91rm9200_wdt",
.id = -1,
- .num_resources = 0,
+ .resource = wdt_resources,
+ .num_resources = 1,
};

static void __init at91_add_device_watchdog(void)
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index d0107d424ee4..0592db68f3a8 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -154,14 +154,14 @@ config ARM_SP805_WATCHDOG

config AT91RM9200_WATCHDOG
tristate "AT91RM9200 watchdog"
- depends on ARCH_AT91RM9200
+ depends on ARCH_AT91 || COMPILE_TEST
help
Watchdog timer embedded into AT91RM9200 chips. This will reboot your
system when the timeout is reached.

config AT91SAM9X_WATCHDOG
tristate "AT91SAM9X / AT91CAP9 watchdog"
- depends on ARCH_AT91 && !ARCH_AT91RM9200
+ depends on ARCH_AT91
select WATCHDOG_CORE
help
Watchdog timer embedded into AT91SAM9X and AT91CAP9 chips. This will
diff --git a/drivers/watchdog/at91rm9200_wdt.c b/drivers/watchdog/at91rm9200_wdt.c
index dee6cc21d270..6b846e009268 100644
--- a/drivers/watchdog/at91rm9200_wdt.c
+++ b/drivers/watchdog/at91rm9200_wdt.c
@@ -26,11 +26,27 @@
#include <linux/uaccess.h>
#include <linux/of.h>
#include <linux/of_device.h>
-#include <mach/at91_st.h>

#define WDT_DEFAULT_TIME 5 /* seconds */
#define WDT_MAX_TIME 256 /* seconds */

+static void __iomem *at91_st_base;
+
+#define at91_st_read(field) \
+ readl(at91_st_base + field)
+
+#define at91_st_write(field, value) \
+ writel(value, at91_st_base + field)
+
+#define AT91_ST_CR 0x00 /* Control Register */
+#define AT91_ST_WDRST (1 << 0) /* Watchdog Timer Restart */
+
+#define AT91_ST_WDMR 0x08 /* Watchdog Mode Register */
+#define AT91_ST_WDV (0xffff << 0) /* Watchdog Counter Value */
+#define AT91_ST_RSTEN (1 << 16) /* Reset Enable */
+#define AT91_ST_EXTEN (1 << 17) /* External Signal Assertion Enable */
+
+
static int wdt_time = WDT_DEFAULT_TIME;
static bool nowayout = WATCHDOG_NOWAYOUT;

@@ -203,12 +222,17 @@ static struct miscdevice at91wdt_miscdev = {

static int at91wdt_probe(struct platform_device *pdev)
{
+ struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
int res;

if (at91wdt_miscdev.parent)
return -EBUSY;
at91wdt_miscdev.parent = &pdev->dev;

+ at91_st_base = devm_ioremap_resource(&pdev->dev, regs);
+ if (!at91_st_base)
+ return -ENXIO;
+
res = misc_register(&at91wdt_miscdev);
if (res)
return res;
@@ -255,6 +279,7 @@ static int at91wdt_resume(struct platform_device *pdev)
#endif

static const struct of_device_id at91_wdt_dt_ids[] = {
+ { .compatible = "atmel,at91rm9200-st" },
{ .compatible = "atmel,at91rm9200-wdt" },
{ /* sentinel */ }
};
@@ -267,7 +292,7 @@ static struct platform_driver at91wdt_driver = {
.suspend = at91wdt_suspend,
.resume = at91wdt_resume,
.driver = {
- .name = "at91_wdt",
+ .name = "at91rm9200_wdt",
.owner = THIS_MODULE,
.of_match_table = at91_wdt_dt_ids,
},