Joonyoung Shim wrote: > > 11/03/2011 10:59 AM, Kukjin Kim 쓴 글: > > Joonyoung Shim wrote: > >> PWM timers use pclk("timers" clk) as parent clk. If this pclk is the > >> disabled state when PWM driver is probed, then it causes wrong read and > >> write operation about registers of PWM. > >> > >> Signed-off-by: Joonyoung Shim<jy0922.shim@xxxxxxxxxxx> > >> Signed-off-by: Kyungmin Park<kyungmin.park@xxxxxxxxxxx> > >> --- > >> arch/arm/plat-samsung/pwm.c | 7 +++++++ > >> 1 files changed, 7 insertions(+), 0 deletions(-) > >> > >> diff --git a/arch/arm/plat-samsung/pwm.c b/arch/arm/plat-samsung/pwm.c > >> index f37457c..dc1185d 100644 > >> --- a/arch/arm/plat-samsung/pwm.c > >> +++ b/arch/arm/plat-samsung/pwm.c > >> @@ -299,6 +299,9 @@ static int s3c_pwm_probe(struct platform_device *pdev) > >> goto err_clk_tin; > >> } > >> > >> + clk_enable(pwm->clk); > >> + clk_enable(pwm->clk_div); > >> + > >> local_irq_save(flags); > >> > >> tcon = __raw_readl(S3C2410_TCON); > >> @@ -326,6 +329,8 @@ static int s3c_pwm_probe(struct platform_device *pdev) > >> return 0; > >> > >> err_clk_tdiv: > >> + clk_disable(pwm->clk_div); > >> + clk_disable(pwm->clk); > >> clk_put(pwm->clk_div); > >> > >> err_clk_tin: > >> @@ -340,6 +345,8 @@ static int __devexit s3c_pwm_remove(struct > >> platform_device *pdev) > >> { > >> struct pwm_device *pwm = platform_get_drvdata(pdev); > >> > >> + clk_disable(pwm->clk_div); > >> + clk_disable(pwm->clk); > >> clk_put(pwm->clk_div); > >> clk_put(pwm->clk); > >> kfree(pwm); > >> -- > >> 1.7.5.4 > > Well, I wonder when this is needed. I think it should be enabled during > > kernel booting... > > The exynos4 machine using just timer turns on "timer" clock in the past, > but "timer" clock is disable state when boot since MCT is used. MCT > doesn't control "timer" clock. > > I think pwm driver should control(enable/disable) using clocks > regardless of their parents clock. > I mean, why that is disabled when kernel boot... Thanks. Best regards, Kgene. -- Kukjin Kim <kgene.kim@xxxxxxxxxxx>, Senior Engineer, SW Solution Development Team, Samsung Electronics Co., Ltd. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html