2021-02-22 22:32:41

by Álvaro Fernández Rojas

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Subject: [PATCH] watchdog: bcm7038_wdt: add big endian support

bcm7038_wdt can be used on bmips (bcm63xx) devices too.

Signed-off-by: Álvaro Fernández Rojas <[email protected]>
---
drivers/watchdog/bcm7038_wdt.c | 30 ++++++++++++++++++++++++------
1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/drivers/watchdog/bcm7038_wdt.c b/drivers/watchdog/bcm7038_wdt.c
index 979caa18d3c8..62494da1ac57 100644
--- a/drivers/watchdog/bcm7038_wdt.c
+++ b/drivers/watchdog/bcm7038_wdt.c
@@ -34,6 +34,24 @@ struct bcm7038_watchdog {

static bool nowayout = WATCHDOG_NOWAYOUT;

+static inline void bcm7038_wdt_write(unsigned long data, void __iomem *reg)
+{
+#ifdef CONFIG_CPU_BIG_ENDIAN
+ __raw_writel(data, reg);
+#else
+ writel(data, reg);
+#endif
+}
+
+static inline unsigned long bcm7038_wdt_read(void __iomem *reg)
+{
+#ifdef CONFIG_CPU_BIG_ENDIAN
+ return __raw_readl(reg);
+#else
+ return readl(reg);
+#endif
+}
+
static void bcm7038_wdt_set_timeout_reg(struct watchdog_device *wdog)
{
struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
@@ -41,15 +59,15 @@ static void bcm7038_wdt_set_timeout_reg(struct watchdog_device *wdog)

timeout = wdt->rate * wdog->timeout;

- writel(timeout, wdt->base + WDT_TIMEOUT_REG);
+ bcm7038_wdt_write(timeout, wdt->base + WDT_TIMEOUT_REG);
}

static int bcm7038_wdt_ping(struct watchdog_device *wdog)
{
struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);

- writel(WDT_START_1, wdt->base + WDT_CMD_REG);
- writel(WDT_START_2, wdt->base + WDT_CMD_REG);
+ bcm7038_wdt_write(WDT_START_1, wdt->base + WDT_CMD_REG);
+ bcm7038_wdt_write(WDT_START_2, wdt->base + WDT_CMD_REG);

return 0;
}
@@ -66,8 +84,8 @@ static int bcm7038_wdt_stop(struct watchdog_device *wdog)
{
struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);

- writel(WDT_STOP_1, wdt->base + WDT_CMD_REG);
- writel(WDT_STOP_2, wdt->base + WDT_CMD_REG);
+ bcm7038_wdt_write(WDT_STOP_1, wdt->base + WDT_CMD_REG);
+ bcm7038_wdt_write(WDT_STOP_2, wdt->base + WDT_CMD_REG);

return 0;
}
@@ -88,7 +106,7 @@ static unsigned int bcm7038_wdt_get_timeleft(struct watchdog_device *wdog)
struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
u32 time_left;

- time_left = readl(wdt->base + WDT_CMD_REG);
+ time_left = bcm7038_wdt_read(wdt->base + WDT_CMD_REG);

return time_left / wdt->rate;
}
--
2.20.1


2021-02-22 22:41:33

by Guenter Roeck

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Subject: Re: [PATCH] watchdog: bcm7038_wdt: add big endian support

On 2/22/21 12:03 PM, Álvaro Fernández Rojas wrote:
> bcm7038_wdt can be used on bmips (bcm63xx) devices too.
>
It might make sense to actually enable it for BCM63XX.

> Signed-off-by: Álvaro Fernández Rojas <[email protected]>
> ---
> drivers/watchdog/bcm7038_wdt.c | 30 ++++++++++++++++++++++++------
> 1 file changed, 24 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/watchdog/bcm7038_wdt.c b/drivers/watchdog/bcm7038_wdt.c
> index 979caa18d3c8..62494da1ac57 100644
> --- a/drivers/watchdog/bcm7038_wdt.c
> +++ b/drivers/watchdog/bcm7038_wdt.c
> @@ -34,6 +34,24 @@ struct bcm7038_watchdog {
>
> static bool nowayout = WATCHDOG_NOWAYOUT;
>
> +static inline void bcm7038_wdt_write(unsigned long data, void __iomem *reg)
> +{
> +#ifdef CONFIG_CPU_BIG_ENDIAN
> + __raw_writel(data, reg);
> +#else
> + writel(data, reg);
> +#endif
> +}
> +
> +static inline unsigned long bcm7038_wdt_read(void __iomem *reg)
> +{
> +#ifdef CONFIG_CPU_BIG_ENDIAN
> + return __raw_readl(reg);
> +#else
> + return readl(reg);
> +#endif
> +}
> +

This needs further explanation. Why not just use __raw_writel() and
__raw_readl() unconditionally ? Also, is it known for sure that,
say, bmips_be_defconfig otherwise uses the wrong endianness
(vs. bmips_stb_defconfig which is a little endian configuration) ?

Thanks,
Guenter

> static void bcm7038_wdt_set_timeout_reg(struct watchdog_device *wdog)
> {
> struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
> @@ -41,15 +59,15 @@ static void bcm7038_wdt_set_timeout_reg(struct watchdog_device *wdog)
>
> timeout = wdt->rate * wdog->timeout;
>
> - writel(timeout, wdt->base + WDT_TIMEOUT_REG);
> + bcm7038_wdt_write(timeout, wdt->base + WDT_TIMEOUT_REG);
> }
>
> static int bcm7038_wdt_ping(struct watchdog_device *wdog)
> {
> struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
>
> - writel(WDT_START_1, wdt->base + WDT_CMD_REG);
> - writel(WDT_START_2, wdt->base + WDT_CMD_REG);
> + bcm7038_wdt_write(WDT_START_1, wdt->base + WDT_CMD_REG);
> + bcm7038_wdt_write(WDT_START_2, wdt->base + WDT_CMD_REG);
>
> return 0;
> }
> @@ -66,8 +84,8 @@ static int bcm7038_wdt_stop(struct watchdog_device *wdog)
> {
> struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
>
> - writel(WDT_STOP_1, wdt->base + WDT_CMD_REG);
> - writel(WDT_STOP_2, wdt->base + WDT_CMD_REG);
> + bcm7038_wdt_write(WDT_STOP_1, wdt->base + WDT_CMD_REG);
> + bcm7038_wdt_write(WDT_STOP_2, wdt->base + WDT_CMD_REG);
>
> return 0;
> }
> @@ -88,7 +106,7 @@ static unsigned int bcm7038_wdt_get_timeleft(struct watchdog_device *wdog)
> struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
> u32 time_left;
>
> - time_left = readl(wdt->base + WDT_CMD_REG);
> + time_left = bcm7038_wdt_read(wdt->base + WDT_CMD_REG);
>
> return time_left / wdt->rate;
> }
>

2021-02-23 08:08:20

by Álvaro Fernández Rojas

[permalink] [raw]
Subject: [PATCH v2] watchdog: bcm7038_wdt: add big endian support

bcm7038_wdt can be used on bmips big endian (bcm63xx) devices too.

Signed-off-by: Álvaro Fernández Rojas <[email protected]>
---
v2: use approach indicated by Florian (same as bcmgenet.c)

drivers/watchdog/bcm7038_wdt.c | 31 +++++++++++++++++++++++++------
1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/drivers/watchdog/bcm7038_wdt.c b/drivers/watchdog/bcm7038_wdt.c
index 979caa18d3c8..acaaa0005d5b 100644
--- a/drivers/watchdog/bcm7038_wdt.c
+++ b/drivers/watchdog/bcm7038_wdt.c
@@ -34,6 +34,25 @@ struct bcm7038_watchdog {

static bool nowayout = WATCHDOG_NOWAYOUT;

+static inline void bcm7038_wdt_write(u32 value, void __iomem *addr)
+{
+ /* MIPS chips strapped for BE will automagically configure the
+ * peripheral registers for CPU-native byte order.
+ */
+ if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
+ __raw_writel(value, addr);
+ else
+ writel_relaxed(value, addr);
+}
+
+static inline u32 bcm7038_wdt_read(void __iomem *addr)
+{
+ if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
+ return __raw_readl(addr);
+ else
+ return readl_relaxed(addr);
+}
+
static void bcm7038_wdt_set_timeout_reg(struct watchdog_device *wdog)
{
struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
@@ -41,15 +60,15 @@ static void bcm7038_wdt_set_timeout_reg(struct watchdog_device *wdog)

timeout = wdt->rate * wdog->timeout;

- writel(timeout, wdt->base + WDT_TIMEOUT_REG);
+ bcm7038_wdt_write(timeout, wdt->base + WDT_TIMEOUT_REG);
}

static int bcm7038_wdt_ping(struct watchdog_device *wdog)
{
struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);

- writel(WDT_START_1, wdt->base + WDT_CMD_REG);
- writel(WDT_START_2, wdt->base + WDT_CMD_REG);
+ bcm7038_wdt_write(WDT_START_1, wdt->base + WDT_CMD_REG);
+ bcm7038_wdt_write(WDT_START_2, wdt->base + WDT_CMD_REG);

return 0;
}
@@ -66,8 +85,8 @@ static int bcm7038_wdt_stop(struct watchdog_device *wdog)
{
struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);

- writel(WDT_STOP_1, wdt->base + WDT_CMD_REG);
- writel(WDT_STOP_2, wdt->base + WDT_CMD_REG);
+ bcm7038_wdt_write(WDT_STOP_1, wdt->base + WDT_CMD_REG);
+ bcm7038_wdt_write(WDT_STOP_2, wdt->base + WDT_CMD_REG);

return 0;
}
@@ -88,7 +107,7 @@ static unsigned int bcm7038_wdt_get_timeleft(struct watchdog_device *wdog)
struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
u32 time_left;

- time_left = readl(wdt->base + WDT_CMD_REG);
+ time_left = bcm7038_wdt_read(wdt->base + WDT_CMD_REG);

return time_left / wdt->rate;
}
--
2.20.1

2021-02-23 15:23:30

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH v2] watchdog: bcm7038_wdt: add big endian support

On 2/23/21 12:00 AM, Álvaro Fernández Rojas wrote:
> bcm7038_wdt can be used on bmips big endian (bcm63xx) devices too.
>
> Signed-off-by: Álvaro Fernández Rojas <[email protected]>

With the assumption that the driver indeed does not need memory
barriers,

Reviewed-by: Guenter Roeck <[email protected]>

Thanks,
Guenter