diff options
| author | Simon South <simon@simonsouth.net> | 2021-01-19 19:12:09 +0300 |
|---|---|---|
| committer | Thierry Reding <thierry.reding@gmail.com> | 2021-01-20 20:13:32 +0300 |
| commit | 11be938ae003c1cf157f0e80d5c9ad29a0f4c34c (patch) | |
| tree | e6f28027a57ef125d37ca3658091ebe6eb704d45 | |
| parent | d21ba5d6217bd5a6a696678385906ed1994b380b (diff) | |
| download | linux-11be938ae003c1cf157f0e80d5c9ad29a0f4c34c.tar.xz | |
pwm: rockchip: Enable clock before calling clk_get_rate()
The documentation for clk_get_rate() in include/linux/clk.h states the
function's result is valid only for a clock source that has been
enabled. However, the Rockchip PWM driver uses this function in two places
to query the rate of a clock without first ensuring it is enabled.
Fix this by modifying rockchip_pwm_get_state() and rockchip_pwm_apply() so
they enable a device's PWM clock before querying its rate (in the latter
case, the querying is actually done in rockchip_pwm_config()) and disable
the clock again before returning.
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Simon South <simon@simonsouth.net>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
| -rw-r--r-- | drivers/pwm/pwm-rockchip.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c index 228147e9bc6e..6ad7d0a50aed 100644 --- a/drivers/pwm/pwm-rockchip.c +++ b/drivers/pwm/pwm-rockchip.c @@ -72,6 +72,10 @@ static void rockchip_pwm_get_state(struct pwm_chip *chip, if (ret) return; + ret = clk_enable(pc->clk); + if (ret) + return; + clk_rate = clk_get_rate(pc->clk); tmp = readl_relaxed(pc->base + pc->data->regs.period); @@ -90,6 +94,7 @@ static void rockchip_pwm_get_state(struct pwm_chip *chip, else state->polarity = PWM_POLARITY_NORMAL; + clk_disable(pc->clk); clk_disable(pc->pclk); } @@ -189,6 +194,10 @@ static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, if (ret) return ret; + ret = clk_enable(pc->clk); + if (ret) + return ret; + pwm_get_state(pwm, &curstate); enabled = curstate.enabled; @@ -208,6 +217,7 @@ static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, } out: + clk_disable(pc->clk); clk_disable(pc->pclk); return ret; |