lkml.org 
[lkml]   [2020]   [Jan]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] watchdog: da9062: make restart handler atomic safe
Date
The restart handler is executed during the shutdown phase which is
atomic/irq-less. The i2c framework supports atomic transfers since
commit 63b96983a5dd ("i2c: core: introduce callbacks for atomic
transfers") but unfortunately the regmap framework doesn't support it
yet. Hard coding the i2c stuff can be done without worries since the
DA9062 is an i2c-only device.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
Hi,

This patch is based on Stefan Lengfeld's RFC Patch [1].

[1] https://patchwork.ozlabs.org/patch/1085942/
---
drivers/watchdog/da9062_wdt.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/watchdog/da9062_wdt.c b/drivers/watchdog/da9062_wdt.c
index c9b9d6394525..84c5a0a455b2 100644
--- a/drivers/watchdog/da9062_wdt.c
+++ b/drivers/watchdog/da9062_wdt.c
@@ -11,6 +11,7 @@
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
+#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/mfd/da9062/registers.h>
@@ -149,12 +150,18 @@ static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
void *data)
{
struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
+ struct i2c_client *client = to_i2c_client(wdt->hw->dev);
+ u8 buf[] = {DA9062AA_CONTROL_F, DA9062AA_SHUTDOWN_MASK};
+ struct i2c_msg msg = {
+ .addr = client->addr,
+ .flags = 0,
+ .len = sizeof(buf),
+ .buf = buf,
+ };
int ret;

- ret = regmap_write(wdt->hw->regmap,
- DA9062AA_CONTROL_F,
- DA9062AA_SHUTDOWN_MASK);
- if (ret)
+ ret = i2c_transfer(client->adapter, &msg, 1);
+ if (ret < 0)
dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
ret);

--
2.20.1
\
 
 \ /
  Last update: 2020-01-13 10:16    [W:0.106 / U:0.104 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site