2015-11-24 00:00:49

by Alban

Subject: [PATCH] reset: ath79: Add system restart support

Add a system restart handler that use the FULL_CHIP_RESET bit of the
reset controller.

Signed-off-by: Alban Bedel <[email protected]>
---
drivers/reset/reset-ath79.c | 30 +++++++++++++++++++++++++++++-
1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/drivers/reset/reset-ath79.c b/drivers/reset/reset-ath79.c
index 9aaf646..692fc89 100644
--- a/drivers/reset/reset-ath79.c
+++ b/drivers/reset/reset-ath79.c
@@ -15,13 +15,17 @@
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/reset-controller.h>
+#include <linux/reboot.h>

struct ath79_reset {
struct reset_controller_dev rcdev;
+ struct notifier_block restart_nb;
void __iomem *base;
spinlock_t lock;
};

+#define FULL_CHIP_RESET 24
+
static int ath79_reset_update(struct reset_controller_dev *rcdev,
unsigned long id, bool assert)
{
@@ -72,10 +76,22 @@ static struct reset_control_ops ath79_reset_ops = {
.status = ath79_reset_status,
};

+static int ath79_reset_restart_handler(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct ath79_reset *ath79_reset =
+ container_of(nb, struct ath79_reset, restart_nb);
+
+ ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET);
+
+ return NOTIFY_DONE;
+}
+
static int ath79_reset_probe(struct platform_device *pdev)
{
struct ath79_reset *ath79_reset;
struct resource *res;
+ int err;

ath79_reset = devm_kzalloc(&pdev->dev,
sizeof(*ath79_reset), GFP_KERNEL);
@@ -96,13 +112,25 @@ static int ath79_reset_probe(struct platform_device *pdev)
ath79_reset->rcdev.of_reset_n_cells = 1;
ath79_reset->rcdev.nr_resets = 32;

- return reset_controller_register(&ath79_reset->rcdev);
+ err = reset_controller_register(&ath79_reset->rcdev);
+ if (err)
+ return err;
+
+ ath79_reset->restart_nb.notifier_call = ath79_reset_restart_handler;
+ ath79_reset->restart_nb.priority = 128;
+
+ err = register_restart_handler(&ath79_reset->restart_nb);
+ if (err)
+ dev_warn(&pdev->dev, "Failed to register restart handler\n");
+
+ return 0;
}

static int ath79_reset_remove(struct platform_device *pdev)
{
struct ath79_reset *ath79_reset = platform_get_drvdata(pdev);

+ unregister_restart_handler(&ath79_reset->restart_nb);
reset_controller_unregister(&ath79_reset->rcdev);

return 0;
--
2.0.0

2015-11-24 12:01:49

by Philipp Zabel

Subject: Re: [PATCH] reset: ath79: Add system restart support

Hi Alban,

Am Dienstag, den 24.11.2015, 01:00 +0100 schrieb Alban Bedel:
> Add a system restart handler that use the FULL_CHIP_RESET bit of the
> reset controller.
>
> Signed-off-by: Alban Bedel <[email protected]>

Applied, thanks.

Btw, should this driver #include <linux/io.h> for readl/writel?

regards
Philipp

2015-11-24 18:33:58

by Alban

Subject: Re: [PATCH] reset: ath79: Add system restart support

On Tue, 24 Nov 2015 13:01:46 +0100
Philipp Zabel <[email protected]> wrote:

> Hi Alban,
>
> Am Dienstag, den 24.11.2015, 01:00 +0100 schrieb Alban Bedel:
> > Add a system restart handler that use the FULL_CHIP_RESET bit of the
> > reset controller.
> >
> > Signed-off-by: Alban Bedel <[email protected]>
>
> Applied, thanks.

Thanks to you :)

> Btw, should this driver #include <linux/io.h> for readl/writel?

Good question :) It turns out to be a MIPS glitch, asm/io.h is included
by asm/page.h which here come from linux/module.h. But we shouldn't
rely on this glitch and the driver should #include <linux/io.h>.
I'll fix this and add support for CONFIG_COMPILE_TEST to better catch
this kind of bugs in the future.

Alban