| Message ID | 1353290780-19413-3-git-send-email-linux@prisktech.co.nz (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Nov 19, 2012 at 03:06:20PM +1300, Tony Prisk wrote: > When all PWMs are disabled, PWM module may be disabled during > calls to pwm_config. This patch enables/disables the clock in > pwm_config to ensure the module is active before register read/ > writes. > > Signed-off-by: Tony Prisk <linux@prisktech.co.nz> > --- > drivers/pwm/pwm-vt8500.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c > index 806f72c..cc97af9 100644 > --- a/drivers/pwm/pwm-vt8500.c > +++ b/drivers/pwm/pwm-vt8500.c > @@ -63,6 +63,8 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, > unsigned long long c; > unsigned long period_cycles, prescale, pv, dc; > > + clk_enable(vt8500->clk); This needs a check of the return value. Other than that, looks good. Thierry
diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c index 806f72c..cc97af9 100644 --- a/drivers/pwm/pwm-vt8500.c +++ b/drivers/pwm/pwm-vt8500.c @@ -63,6 +63,8 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, unsigned long long c; unsigned long period_cycles, prescale, pv, dc; + clk_enable(vt8500->clk); + c = clk_get_rate(vt8500->clk); c = c * period_ns; do_div(c, 1000000000); @@ -75,8 +77,10 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, if (pv > 4095) pv = 4095; - if (prescale > 1023) + if (prescale > 1023) { + clk_disable(vt8500->clk); return -EINVAL; + } c = (unsigned long long)pv * duty_ns; do_div(c, period_ns); @@ -91,6 +95,7 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, pwm_busy_wait(vt8500->base + 0x40 + pwm->hwpwm, (1 << 3)); writel(dc, vt8500->base + 0xc + (pwm->hwpwm << 4)); + clk_disable(vt8500->clk); return 0; }
When all PWMs are disabled, PWM module may be disabled during calls to pwm_config. This patch enables/disables the clock in pwm_config to ensure the module is active before register read/ writes. Signed-off-by: Tony Prisk <linux@prisktech.co.nz> --- drivers/pwm/pwm-vt8500.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)