Currently .get_state() and .apply() use dev_get_drvdata() on the struct
device related to the pwm chip. This only works after .probe() called
platform_set_drvdata() which in this driver happens only after
pwmchip_add() and so comes possibly too late.
Instead of setting the driver data earlier use the traditional
container_of approach as this way the driver data is conceptually and
computational nearer.
Fixes: 9db33d221efc ("pwm: Add support for sl28cpld PWM controller")
Tested-by: Michael Walle <mich...@walle.cc>
Signed-off-by: Uwe Kleine-König <u.kleine-koe...@pengutronix.de>
---
Hello Linus,
Thierry (who usually sends PWM patches to you) didn't react to this
patch sent to the pwm Mailinglist last week
(https://lore.kernel.org/r/20201124212432.3117322-1-u.kleine-koe...@pengutronix.de)
yet.
Given v5.10 isn't far away any more and I don't know when Thierry will
take a look and act, I'm sending this directly to you. The affected
driver was new in 5.10-rc1 and at least once the unpatched driver
created an oops:
https://lavalab.kontron.com/scheduler/job/108#L950
Michael Walle who tested this patch is the original author of the
driver. IMHO it would be good to have this fixed before 5.10.
If you prefer a pull request, I can setup something (but I don't have
access to Thierry's tree, so it will be for a repository that's new to
you).
Best regards
Uwe
drivers/pwm/pwm-sl28cpld.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/pwm/pwm-sl28cpld.c b/drivers/pwm/pwm-sl28cpld.c
index 5046b6b7fd35..b4c651fc749c 100644
--- a/drivers/pwm/pwm-sl28cpld.c
+++ b/drivers/pwm/pwm-sl28cpld.c
@@ -84,12 +84,14 @@ struct sl28cpld_pwm {
struct regmap *regmap;
u32 offset;
};
+#define sl28cpld_pwm_from_chip(_chip) \
+ container_of(_chip, struct sl28cpld_pwm, pwm_chip)
static void sl28cpld_pwm_get_state(struct pwm_chip *chip,
struct pwm_device *pwm,
struct pwm_state *state)
{
- struct sl28cpld_pwm *priv = dev_get_drvdata(chip->dev);
+ struct sl28cpld_pwm *priv = sl28cpld_pwm_from_chip(chip);
unsigned int reg;
int prescaler;
@@ -118,7 +120,7 @@ static void sl28cpld_pwm_get_state(struct pwm_chip *chip,
static int sl28cpld_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
- struct sl28cpld_pwm *priv = dev_get_drvdata(chip->dev);
+ struct sl28cpld_pwm *priv = sl28cpld_pwm_from_chip(chip);
unsigned int cycle, prescaler;
bool write_duty_cycle_first;
int ret;
--
2.29.2
