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| author | Thierry Reding <thierry.reding@gmail.com> | 2019-10-21 13:51:56 +0300 |
|---|---|---|
| committer | Thierry Reding <thierry.reding@gmail.com> | 2019-12-09 12:05:41 +0300 |
| commit | cfc4c189bc70b1acc17e6f1abf1dc1c0ae890bd8 (patch) | |
| tree | 9831fc05aad7280b76944a4d7ca809070f81ebef /drivers/pwm | |
| parent | e42617b825f8073569da76dc4510bfa019b1c35a (diff) | |
| download | linux-cfc4c189bc70b1acc17e6f1abf1dc1c0ae890bd8.tar.xz | |
pwm: Read initial hardware state at request time
Drivers that support reading the hardware state (using ->get_state())
may want to rely on per-PWM data to do so. Defer reading the hardware
state for the first time until the PWM has been requested and after
drivers have had a chance to allocate per-PWM data.
Conceptually this is also a more natural place to read the hardware
state because the PWM core doesn't need to know the hardware state of a
PWM unless there is a user for it. This also ensures that the state is
read everytime a user requests a PWM. If the PWM changes between users
for some reason, the PWM core will reload the state from hardware and
keep its copy of the state up-to-date.
Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm')
| -rw-r--r-- | drivers/pwm/core.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index f877e77d9184..e067873c6cc5 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -114,6 +114,9 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label) } } + if (pwm->chip->ops->get_state) + pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state); + set_bit(PWMF_REQUESTED, &pwm->flags); pwm->label = label; @@ -283,9 +286,6 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip, pwm->hwpwm = i; pwm->state.polarity = polarity; - if (chip->ops->get_state) - chip->ops->get_state(chip, pwm, &pwm->state); - radix_tree_insert(&pwm_tree, pwm->pwm, pwm); } |