Re: [PATCH 1/6] ARM: ks8695: watchdog: stop using mach/*.h

From: Greg Ungerer
Date: Fri May 03 2019 - 03:02:57 EST


Hi Arnd,

On 16/4/19 6:24 am, Arnd Bergmann wrote:
drivers should not rely on machine specific headers but
get their information from the platform device.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

I dug out some old ks8695 based hardware to try this out.
I had a lot of trouble getting anything modern working on it.
In the end I still don't have a reliable test bed to test this properly.

Your patch series works as well as the kernel before the changes,
so I am happy enough to ack them as they are.

Acked-by: Greg Ungerer <gerg@xxxxxxxxxx>

Ultimately though I am left wondering if the ks8695 support in the
kernel is useful to anyone the way it is at the moment. With a minimal
kernel configuration I can boot up to a shell - but the system is
really unreliable if you try to interactively use it. I don't think
it is the hardware - it seems to run reliably with the old code
it has running from flash on it. I am only testing the new kernel,
running with the existing user space root filesystem on it (which
dates from 2004 :-)

Regards
Greg



arch/arm/mach-ks8695/devices.c | 13 ++++++++++++-
drivers/watchdog/Kconfig | 2 +-
drivers/watchdog/ks8695_wdt.c | 30 +++++++++++++++++-------------
3 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/arch/arm/mach-ks8695/devices.c b/arch/arm/mach-ks8695/devices.c
index 61cf20beb45f..57766817d86f 100644
--- a/arch/arm/mach-ks8695/devices.c
+++ b/arch/arm/mach-ks8695/devices.c
@@ -169,11 +169,22 @@ void __init ks8696_add_device_hpna(void)
/* --------------------------------------------------------------------
* Watchdog
* -------------------------------------------------------------------- */
+#define KS8695_TMR_OFFSET (0xF0000 + 0xE400)
+#define KS8695_TMR_PA (KS8695_IO_PA + KS8695_TMR_OFFSET)
+static struct resource ks8695_wdt_resources[] = {
+ [0] = {
+ .name = "tmr",
+ .start = KS8695_TMR_PA,
+ .end = KS8695_TMR_PA + 0xf,
+ .flags = IORESOURCE_MEM,
+ },
+};
static struct platform_device ks8695_wdt_device = {
.name = "ks8695_wdt",
.id = -1,
- .num_resources = 0,
+ .resource = ks8695_wdt_resources,
+ .num_resources = ARRAY_SIZE(ks8695_wdt_resources),
};
static void __init ks8695_add_device_watchdog(void)
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 242eea859637..046e01daef57 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -397,7 +397,7 @@ config IXP4XX_WATCHDOG
config KS8695_WATCHDOG
tristate "KS8695 watchdog"
- depends on ARCH_KS8695
+ depends on ARCH_KS8695 || COMPILE_TEST
help
Watchdog timer embedded into KS8695 processor. This will reboot your
system when the timeout is reached.
diff --git a/drivers/watchdog/ks8695_wdt.c b/drivers/watchdog/ks8695_wdt.c
index 1e41818a44bc..87c542c2f912 100644
--- a/drivers/watchdog/ks8695_wdt.c
+++ b/drivers/watchdog/ks8695_wdt.c
@@ -23,10 +23,8 @@
#include <linux/watchdog.h>
#include <linux/io.h>
#include <linux/uaccess.h>
-#include <mach/hardware.h>
-#define KS8695_TMR_OFFSET (0xF0000 + 0xE400)
-#define KS8695_TMR_VA (KS8695_IO_VA + KS8695_TMR_OFFSET)
+#define KS8695_CLOCK_RATE 25000000
/*
* Timer registers
@@ -57,6 +55,7 @@ MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
static unsigned long ks8695wdt_busy;
static DEFINE_SPINLOCK(ks8695_lock);
+static void __iomem *tmr_reg;
/* ......................................................................... */
@@ -69,8 +68,8 @@ static inline void ks8695_wdt_stop(void)
spin_lock(&ks8695_lock);
/* disable timer0 */
- tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
- __raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
+ tmcon = __raw_readl(tmr_reg + KS8695_TMCON);
+ __raw_writel(tmcon & ~TMCON_T0EN, tmr_reg + KS8695_TMCON);
spin_unlock(&ks8695_lock);
}
@@ -84,15 +83,15 @@ static inline void ks8695_wdt_start(void)
spin_lock(&ks8695_lock);
/* disable timer0 */
- tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
- __raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
+ tmcon = __raw_readl(tmr_reg + KS8695_TMCON);
+ __raw_writel(tmcon & ~TMCON_T0EN, tmr_reg + KS8695_TMCON);
/* program timer0 */
- __raw_writel(tval | T0TC_WATCHDOG, KS8695_TMR_VA + KS8695_T0TC);
+ __raw_writel(tval | T0TC_WATCHDOG, tmr_reg + KS8695_T0TC);
/* re-enable timer0 */
- tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
- __raw_writel(tmcon | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
+ tmcon = __raw_readl(tmr_reg + KS8695_TMCON);
+ __raw_writel(tmcon | TMCON_T0EN, tmr_reg + KS8695_TMCON);
spin_unlock(&ks8695_lock);
}
@@ -105,9 +104,9 @@ static inline void ks8695_wdt_reload(void)
spin_lock(&ks8695_lock);
/* disable, then re-enable timer0 */
- tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
- __raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
- __raw_writel(tmcon | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
+ tmcon = __raw_readl(tmr_reg + KS8695_TMCON);
+ __raw_writel(tmcon & ~TMCON_T0EN, tmr_reg + KS8695_TMCON);
+ __raw_writel(tmcon | TMCON_T0EN, tmr_reg + KS8695_TMCON);
spin_unlock(&ks8695_lock);
}
@@ -238,6 +237,11 @@ static struct miscdevice ks8695wdt_miscdev = {
static int ks8695wdt_probe(struct platform_device *pdev)
{
int res;
+ struct resource *resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ tmr_reg = devm_ioremap_resource(&pdev->dev, resource);
+ if (!tmr_reg)
+ return -ENXIO;
if (ks8695wdt_miscdev.parent)
return -EBUSY;