| Message ID | e3afc6e297e495322971c26a79c6f841d5952fd1.1610362661.git.baruch@tkos.co.il (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | gpio: mvebu: pwm fixes and improvements | expand |
Hello Baruch, $Subject ~= s/get_state/.get_state/ ? On Mon, Jan 11, 2021 at 01:17:02PM +0200, Baruch Siach wrote: > The period is the sum of on and off values. > > Reported-by: Russell King <linux@armlinux.org.uk> > Fixes: 757642f9a584e ("gpio: mvebu: Add limited PWM support") > Signed-off-by: Baruch Siach <baruch@tkos.co.il> > --- > drivers/gpio/gpio-mvebu.c | 19 ++++++++----------- > 1 file changed, 8 insertions(+), 11 deletions(-) > > diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c > index 672681a976f5..a912a8fed197 100644 > --- a/drivers/gpio/gpio-mvebu.c > +++ b/drivers/gpio/gpio-mvebu.c > @@ -676,20 +676,17 @@ static void mvebu_pwm_get_state(struct pwm_chip *chip, > else > state->duty_cycle = 1; > > + val = (unsigned long long) u; /* on duration */ > regmap_read(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm), &u); > - val = (unsigned long long) u * NSEC_PER_SEC; > + val += (unsigned long long) u; /* period = on + off duration */ > + val *= NSEC_PER_SEC; > do_div(val, mvpwm->clk_rate); > - if (val < state->duty_cycle) { > + if (val > UINT_MAX) > + state->period = UINT_MAX; > + else if (val) > + state->period = val; > + else > state->period = 1; > - } else { > - val -= state->duty_cycle; > - if (val > UINT_MAX) > - state->period = UINT_MAX; > - else if (val) > - state->period = val; > - else > - state->period = 1; > - } The patch looks good, the patch description could be a bit more verbose. Something like: Calculate the period as ($on + $off) / clkrate instead of $off / clkrate - $on / clkrate . Best regards Uwe
Hi Uwe, On Mon, Jan 11 2021, Uwe Kleine-König wrote: > $Subject ~= s/get_state/.get_state/ ? Ack. > On Mon, Jan 11, 2021 at 01:17:02PM +0200, Baruch Siach wrote: >> The period is the sum of on and off values. >> >> Reported-by: Russell King <linux@armlinux.org.uk> >> Fixes: 757642f9a584e ("gpio: mvebu: Add limited PWM support") >> Signed-off-by: Baruch Siach <baruch@tkos.co.il> >> --- >> drivers/gpio/gpio-mvebu.c | 19 ++++++++----------- >> 1 file changed, 8 insertions(+), 11 deletions(-) >> >> diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c >> index 672681a976f5..a912a8fed197 100644 >> --- a/drivers/gpio/gpio-mvebu.c >> +++ b/drivers/gpio/gpio-mvebu.c >> @@ -676,20 +676,17 @@ static void mvebu_pwm_get_state(struct pwm_chip *chip, >> else >> state->duty_cycle = 1; >> >> + val = (unsigned long long) u; /* on duration */ >> regmap_read(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm), &u); >> - val = (unsigned long long) u * NSEC_PER_SEC; >> + val += (unsigned long long) u; /* period = on + off duration */ >> + val *= NSEC_PER_SEC; >> do_div(val, mvpwm->clk_rate); >> - if (val < state->duty_cycle) { >> + if (val > UINT_MAX) >> + state->period = UINT_MAX; >> + else if (val) >> + state->period = val; >> + else >> state->period = 1; >> - } else { >> - val -= state->duty_cycle; >> - if (val > UINT_MAX) >> - state->period = UINT_MAX; >> - else if (val) >> - state->period = val; >> - else >> - state->period = 1; >> - } > > The patch looks good, the patch description could be a bit more verbose. > Something like: > > Calculate the period as > > ($on + $off) / clkrate > > instead of > > $off / clkrate - $on / clkrate > > . I take this to refer to the next patch (2/5). This patch changes from buggy $on / clkrate to ($on + $off) / clkrate baruch
On Wed, Jan 13, 2021 at 08:36:12AM +0200, Baruch Siach wrote: > Hi Uwe, > > On Mon, Jan 11 2021, Uwe Kleine-König wrote: > > $Subject ~= s/get_state/.get_state/ ? > > Ack. > > > On Mon, Jan 11, 2021 at 01:17:02PM +0200, Baruch Siach wrote: > >> The period is the sum of on and off values. > >> > >> Reported-by: Russell King <linux@armlinux.org.uk> > >> Fixes: 757642f9a584e ("gpio: mvebu: Add limited PWM support") > >> Signed-off-by: Baruch Siach <baruch@tkos.co.il> > >> --- > >> drivers/gpio/gpio-mvebu.c | 19 ++++++++----------- > >> 1 file changed, 8 insertions(+), 11 deletions(-) > >> > >> diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c > >> index 672681a976f5..a912a8fed197 100644 > >> --- a/drivers/gpio/gpio-mvebu.c > >> +++ b/drivers/gpio/gpio-mvebu.c > >> @@ -676,20 +676,17 @@ static void mvebu_pwm_get_state(struct pwm_chip *chip, > >> else > >> state->duty_cycle = 1; > >> > >> + val = (unsigned long long) u; /* on duration */ > >> regmap_read(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm), &u); > >> - val = (unsigned long long) u * NSEC_PER_SEC; > >> + val += (unsigned long long) u; /* period = on + off duration */ > >> + val *= NSEC_PER_SEC; > >> do_div(val, mvpwm->clk_rate); > >> - if (val < state->duty_cycle) { > >> + if (val > UINT_MAX) > >> + state->period = UINT_MAX; > >> + else if (val) > >> + state->period = val; > >> + else > >> state->period = 1; > >> - } else { > >> - val -= state->duty_cycle; > >> - if (val > UINT_MAX) > >> - state->period = UINT_MAX; > >> - else if (val) > >> - state->period = val; > >> - else > >> - state->period = 1; > >> - } > > > > The patch looks good, the patch description could be a bit more verbose. > > Something like: > > > > Calculate the period as > > > > ($on + $off) / clkrate > > > > instead of > > > > $off / clkrate - $on / clkrate > > > > . > > I take this to refer to the next patch (2/5). This patch changes from > buggy > > $on / clkrate No, the previous calculation had - val -= state->duty_cycle; which accounts for "- $on / clkrate". Best regards Uwe
diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c index 672681a976f5..a912a8fed197 100644 --- a/drivers/gpio/gpio-mvebu.c +++ b/drivers/gpio/gpio-mvebu.c @@ -676,20 +676,17 @@ static void mvebu_pwm_get_state(struct pwm_chip *chip, else state->duty_cycle = 1; + val = (unsigned long long) u; /* on duration */ regmap_read(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm), &u); - val = (unsigned long long) u * NSEC_PER_SEC; + val += (unsigned long long) u; /* period = on + off duration */ + val *= NSEC_PER_SEC; do_div(val, mvpwm->clk_rate); - if (val < state->duty_cycle) { + if (val > UINT_MAX) + state->period = UINT_MAX; + else if (val) + state->period = val; + else state->period = 1; - } else { - val -= state->duty_cycle; - if (val > UINT_MAX) - state->period = UINT_MAX; - else if (val) - state->period = val; - else - state->period = 1; - } regmap_read(mvchip->regs, GPIO_BLINK_EN_OFF + mvchip->offset, &u); if (u)
The period is the sum of on and off values. Reported-by: Russell King <linux@armlinux.org.uk> Fixes: 757642f9a584e ("gpio: mvebu: Add limited PWM support") Signed-off-by: Baruch Siach <baruch@tkos.co.il> --- drivers/gpio/gpio-mvebu.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-)