Re: [PATCH v8 4/5] pwm: kona: Add debug info to config function
On 15-05-30 09:42 AM, Tim Kryger wrote:
> On Tue, May 26, 2015 at 1:08 PM, Jonathan Richardson
> wrote:
>> Adds debugging info to config function where duty cycle and period
>> are calculated and verified.
>>
>> Signed-off-by: Jonathan Richardson
>> ---
>> drivers/pwm/pwm-bcm-kona.c | 25 +++--
>> 1 file changed, 23 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c
>> index c87621f..0ddf19b 100644
>> --- a/drivers/pwm/pwm-bcm-kona.c
>> +++ b/drivers/pwm/pwm-bcm-kona.c
>> @@ -138,18 +138,39 @@ static int kona_pwmc_config(struct pwm_chip *chip,
>> struct pwm_device *pwm,
>> dc = div64_u64(val, div);
>>
>> /* If duty_ns or period_ns are not achievable then return */
>> - if (pc < PERIOD_COUNT_MIN || dc < DUTY_CYCLE_HIGH_MIN)
>
> The original code was based on the SPEAr PWM driver which has a non-zero
> PWMDCR_MIN_DUTY such that the second condition here can evaluate to true.
>
> This isn't the case for the Kona PWM where DUTY_CYCLE_HIGH_MIN is zero.
>
>> + if (pc < PERIOD_COUNT_MIN) {
>> + dev_warn(chip->dev,
>> + "%s: pwm[%d]: period=%d is not achievable,
>> pc=%lu, prescale=%lu\n",
>> + __func__, chan, period_ns, pc, prescale);
>> return -EINVAL;
>> + }
>
> Why not just print the minimum allowable period with the provided clock?
>
> I don't think pc and prescale will be particularly helpful to users.
>
> Also, do we really need to print __func__ here?
>
>> +
>> + if (dc < DUTY_CYCLE_HIGH_MIN) {
>> + if (0 != duty_ns) {
>> + dev_warn(chip->dev,
>> + "%s: pwm[%d]: duty cycle=%d is not
>> achievable, dc=%lu, prescale=%lu\n",
>> + __func__, chan, duty_ns, dc,
>> prescale);
>> + }
>> + return -EINVAL;
>> + }
>
> The above block is unreachable code.
>
>>
>> /* If pc and dc are in bounds, the calculation is done */
>> if (pc <= PERIOD_COUNT_MAX && dc <= DUTY_CYCLE_HIGH_MAX)
>> break;
>>
>> /* Otherwise, increase prescale and recalculate pc and dc */
>> - if (++prescale > PRESCALE_MAX)
>> + if (++prescale > PRESCALE_MAX) {
>> + dev_warn(chip->dev,
>> + "%s: pwm[%d]: Prescale (=%lu) within max
>> (=%d) for period=%d and duty cycle=%d is not achievable\n",
>> + __func__, chan, prescale, PRESCALE_MAX,
>> + period_ns, duty_ns);
>> return -EINVAL;
>> + }
>> }
>
> The user got here because they specified a period larger than the maximum
> supported so why not tell them largest value that can be supported instead
> of confusing them with prescale and PRESCALE_MAX?
>
>>
>> + dev_dbg(chip->dev, "pwm[%d]: period=%lu, duty_high=%lu,
>> prescale=%lu\n",
>> + chan, pc, dc, prescale);
>> +
>
> This could be more clear. It prints pc but calls it period.
>
>> /*
>> * Don't apply settings if disabled. The period and duty cycle are
>> * always calculated above to ensure the new values are
>> --
>> 1.7.9.5
>>
We can defer this for now until I can look into it further. It's not a
priority. I'm more concerned with core changes and kona pwm fix.
Thanks,
Jon
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Re: [PATCH v8 4/5] pwm: kona: Add debug info to config function
On 15-05-30 09:42 AM, Tim Kryger wrote:
On Tue, May 26, 2015 at 1:08 PM, Jonathan Richardson
jonat...@broadcom.com wrote:
Adds debugging info to config function where duty cycle and period
are calculated and verified.
Signed-off-by: Jonathan Richardson jonat...@broadcom.com
---
drivers/pwm/pwm-bcm-kona.c | 25 +++--
1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c
index c87621f..0ddf19b 100644
--- a/drivers/pwm/pwm-bcm-kona.c
+++ b/drivers/pwm/pwm-bcm-kona.c
@@ -138,18 +138,39 @@ static int kona_pwmc_config(struct pwm_chip *chip,
struct pwm_device *pwm,
dc = div64_u64(val, div);
/* If duty_ns or period_ns are not achievable then return */
- if (pc PERIOD_COUNT_MIN || dc DUTY_CYCLE_HIGH_MIN)
The original code was based on the SPEAr PWM driver which has a non-zero
PWMDCR_MIN_DUTY such that the second condition here can evaluate to true.
This isn't the case for the Kona PWM where DUTY_CYCLE_HIGH_MIN is zero.
+ if (pc PERIOD_COUNT_MIN) {
+ dev_warn(chip-dev,
+ %s: pwm[%d]: period=%d is not achievable,
pc=%lu, prescale=%lu\n,
+ __func__, chan, period_ns, pc, prescale);
return -EINVAL;
+ }
Why not just print the minimum allowable period with the provided clock?
I don't think pc and prescale will be particularly helpful to users.
Also, do we really need to print __func__ here?
+
+ if (dc DUTY_CYCLE_HIGH_MIN) {
+ if (0 != duty_ns) {
+ dev_warn(chip-dev,
+ %s: pwm[%d]: duty cycle=%d is not
achievable, dc=%lu, prescale=%lu\n,
+ __func__, chan, duty_ns, dc,
prescale);
+ }
+ return -EINVAL;
+ }
The above block is unreachable code.
/* If pc and dc are in bounds, the calculation is done */
if (pc = PERIOD_COUNT_MAX dc = DUTY_CYCLE_HIGH_MAX)
break;
/* Otherwise, increase prescale and recalculate pc and dc */
- if (++prescale PRESCALE_MAX)
+ if (++prescale PRESCALE_MAX) {
+ dev_warn(chip-dev,
+ %s: pwm[%d]: Prescale (=%lu) within max
(=%d) for period=%d and duty cycle=%d is not achievable\n,
+ __func__, chan, prescale, PRESCALE_MAX,
+ period_ns, duty_ns);
return -EINVAL;
+ }
}
The user got here because they specified a period larger than the maximum
supported so why not tell them largest value that can be supported instead
of confusing them with prescale and PRESCALE_MAX?
+ dev_dbg(chip-dev, pwm[%d]: period=%lu, duty_high=%lu,
prescale=%lu\n,
+ chan, pc, dc, prescale);
+
This could be more clear. It prints pc but calls it period.
/*
* Don't apply settings if disabled. The period and duty cycle are
* always calculated above to ensure the new values are
--
1.7.9.5
We can defer this for now until I can look into it further. It's not a
priority. I'm more concerned with core changes and kona pwm fix.
Thanks,
Jon
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Re: [PATCH v8 4/5] pwm: kona: Add debug info to config function
On Tue, May 26, 2015 at 1:08 PM, Jonathan Richardson
wrote:
> Adds debugging info to config function where duty cycle and period
> are calculated and verified.
>
> Signed-off-by: Jonathan Richardson
> ---
> drivers/pwm/pwm-bcm-kona.c | 25 +++--
> 1 file changed, 23 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c
> index c87621f..0ddf19b 100644
> --- a/drivers/pwm/pwm-bcm-kona.c
> +++ b/drivers/pwm/pwm-bcm-kona.c
> @@ -138,18 +138,39 @@ static int kona_pwmc_config(struct pwm_chip *chip,
> struct pwm_device *pwm,
> dc = div64_u64(val, div);
>
> /* If duty_ns or period_ns are not achievable then return */
> - if (pc < PERIOD_COUNT_MIN || dc < DUTY_CYCLE_HIGH_MIN)
The original code was based on the SPEAr PWM driver which has a non-zero
PWMDCR_MIN_DUTY such that the second condition here can evaluate to true.
This isn't the case for the Kona PWM where DUTY_CYCLE_HIGH_MIN is zero.
> + if (pc < PERIOD_COUNT_MIN) {
> + dev_warn(chip->dev,
> + "%s: pwm[%d]: period=%d is not achievable,
> pc=%lu, prescale=%lu\n",
> + __func__, chan, period_ns, pc, prescale);
> return -EINVAL;
> + }
Why not just print the minimum allowable period with the provided clock?
I don't think pc and prescale will be particularly helpful to users.
Also, do we really need to print __func__ here?
> +
> + if (dc < DUTY_CYCLE_HIGH_MIN) {
> + if (0 != duty_ns) {
> + dev_warn(chip->dev,
> + "%s: pwm[%d]: duty cycle=%d is not
> achievable, dc=%lu, prescale=%lu\n",
> + __func__, chan, duty_ns, dc,
> prescale);
> + }
> + return -EINVAL;
> + }
The above block is unreachable code.
>
> /* If pc and dc are in bounds, the calculation is done */
> if (pc <= PERIOD_COUNT_MAX && dc <= DUTY_CYCLE_HIGH_MAX)
> break;
>
> /* Otherwise, increase prescale and recalculate pc and dc */
> - if (++prescale > PRESCALE_MAX)
> + if (++prescale > PRESCALE_MAX) {
> + dev_warn(chip->dev,
> + "%s: pwm[%d]: Prescale (=%lu) within max
> (=%d) for period=%d and duty cycle=%d is not achievable\n",
> + __func__, chan, prescale, PRESCALE_MAX,
> + period_ns, duty_ns);
> return -EINVAL;
> + }
> }
The user got here because they specified a period larger than the maximum
supported so why not tell them largest value that can be supported instead
of confusing them with prescale and PRESCALE_MAX?
>
> + dev_dbg(chip->dev, "pwm[%d]: period=%lu, duty_high=%lu,
> prescale=%lu\n",
> + chan, pc, dc, prescale);
> +
This could be more clear. It prints pc but calls it period.
> /*
> * Don't apply settings if disabled. The period and duty cycle are
> * always calculated above to ensure the new values are
> --
> 1.7.9.5
>
--
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Re: [PATCH v8 4/5] pwm: kona: Add debug info to config function
On Tue, May 26, 2015 at 1:08 PM, Jonathan Richardson
jonat...@broadcom.com wrote:
Adds debugging info to config function where duty cycle and period
are calculated and verified.
Signed-off-by: Jonathan Richardson jonat...@broadcom.com
---
drivers/pwm/pwm-bcm-kona.c | 25 +++--
1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c
index c87621f..0ddf19b 100644
--- a/drivers/pwm/pwm-bcm-kona.c
+++ b/drivers/pwm/pwm-bcm-kona.c
@@ -138,18 +138,39 @@ static int kona_pwmc_config(struct pwm_chip *chip,
struct pwm_device *pwm,
dc = div64_u64(val, div);
/* If duty_ns or period_ns are not achievable then return */
- if (pc PERIOD_COUNT_MIN || dc DUTY_CYCLE_HIGH_MIN)
The original code was based on the SPEAr PWM driver which has a non-zero
PWMDCR_MIN_DUTY such that the second condition here can evaluate to true.
This isn't the case for the Kona PWM where DUTY_CYCLE_HIGH_MIN is zero.
+ if (pc PERIOD_COUNT_MIN) {
+ dev_warn(chip-dev,
+ %s: pwm[%d]: period=%d is not achievable,
pc=%lu, prescale=%lu\n,
+ __func__, chan, period_ns, pc, prescale);
return -EINVAL;
+ }
Why not just print the minimum allowable period with the provided clock?
I don't think pc and prescale will be particularly helpful to users.
Also, do we really need to print __func__ here?
+
+ if (dc DUTY_CYCLE_HIGH_MIN) {
+ if (0 != duty_ns) {
+ dev_warn(chip-dev,
+ %s: pwm[%d]: duty cycle=%d is not
achievable, dc=%lu, prescale=%lu\n,
+ __func__, chan, duty_ns, dc,
prescale);
+ }
+ return -EINVAL;
+ }
The above block is unreachable code.
/* If pc and dc are in bounds, the calculation is done */
if (pc = PERIOD_COUNT_MAX dc = DUTY_CYCLE_HIGH_MAX)
break;
/* Otherwise, increase prescale and recalculate pc and dc */
- if (++prescale PRESCALE_MAX)
+ if (++prescale PRESCALE_MAX) {
+ dev_warn(chip-dev,
+ %s: pwm[%d]: Prescale (=%lu) within max
(=%d) for period=%d and duty cycle=%d is not achievable\n,
+ __func__, chan, prescale, PRESCALE_MAX,
+ period_ns, duty_ns);
return -EINVAL;
+ }
}
The user got here because they specified a period larger than the maximum
supported so why not tell them largest value that can be supported instead
of confusing them with prescale and PRESCALE_MAX?
+ dev_dbg(chip-dev, pwm[%d]: period=%lu, duty_high=%lu,
prescale=%lu\n,
+ chan, pc, dc, prescale);
+
This could be more clear. It prints pc but calls it period.
/*
* Don't apply settings if disabled. The period and duty cycle are
* always calculated above to ensure the new values are
--
1.7.9.5
--
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the body of a message to majord...@vger.kernel.org
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Please read the FAQ at http://www.tux.org/lkml/
[PATCH v8 4/5] pwm: kona: Add debug info to config function
Adds debugging info to config function where duty cycle and period
are calculated and verified.
Signed-off-by: Jonathan Richardson
---
drivers/pwm/pwm-bcm-kona.c | 25 +++--
1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c
index c87621f..0ddf19b 100644
--- a/drivers/pwm/pwm-bcm-kona.c
+++ b/drivers/pwm/pwm-bcm-kona.c
@@ -138,18 +138,39 @@ static int kona_pwmc_config(struct pwm_chip *chip, struct
pwm_device *pwm,
dc = div64_u64(val, div);
/* If duty_ns or period_ns are not achievable then return */
- if (pc < PERIOD_COUNT_MIN || dc < DUTY_CYCLE_HIGH_MIN)
+ if (pc < PERIOD_COUNT_MIN) {
+ dev_warn(chip->dev,
+ "%s: pwm[%d]: period=%d is not achievable,
pc=%lu, prescale=%lu\n",
+ __func__, chan, period_ns, pc, prescale);
return -EINVAL;
+ }
+
+ if (dc < DUTY_CYCLE_HIGH_MIN) {
+ if (0 != duty_ns) {
+ dev_warn(chip->dev,
+ "%s: pwm[%d]: duty cycle=%d is not
achievable, dc=%lu, prescale=%lu\n",
+ __func__, chan, duty_ns, dc, prescale);
+ }
+ return -EINVAL;
+ }
/* If pc and dc are in bounds, the calculation is done */
if (pc <= PERIOD_COUNT_MAX && dc <= DUTY_CYCLE_HIGH_MAX)
break;
/* Otherwise, increase prescale and recalculate pc and dc */
- if (++prescale > PRESCALE_MAX)
+ if (++prescale > PRESCALE_MAX) {
+ dev_warn(chip->dev,
+ "%s: pwm[%d]: Prescale (=%lu) within max (=%d)
for period=%d and duty cycle=%d is not achievable\n",
+ __func__, chan, prescale, PRESCALE_MAX,
+ period_ns, duty_ns);
return -EINVAL;
+ }
}
+ dev_dbg(chip->dev, "pwm[%d]: period=%lu, duty_high=%lu, prescale=%lu\n",
+ chan, pc, dc, prescale);
+
/*
* Don't apply settings if disabled. The period and duty cycle are
* always calculated above to ensure the new values are
--
1.7.9.5
--
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Please read the FAQ at http://www.tux.org/lkml/
[PATCH v8 4/5] pwm: kona: Add debug info to config function
Adds debugging info to config function where duty cycle and period
are calculated and verified.
Signed-off-by: Jonathan Richardson jonat...@broadcom.com
---
drivers/pwm/pwm-bcm-kona.c | 25 +++--
1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c
index c87621f..0ddf19b 100644
--- a/drivers/pwm/pwm-bcm-kona.c
+++ b/drivers/pwm/pwm-bcm-kona.c
@@ -138,18 +138,39 @@ static int kona_pwmc_config(struct pwm_chip *chip, struct
pwm_device *pwm,
dc = div64_u64(val, div);
/* If duty_ns or period_ns are not achievable then return */
- if (pc PERIOD_COUNT_MIN || dc DUTY_CYCLE_HIGH_MIN)
+ if (pc PERIOD_COUNT_MIN) {
+ dev_warn(chip-dev,
+ %s: pwm[%d]: period=%d is not achievable,
pc=%lu, prescale=%lu\n,
+ __func__, chan, period_ns, pc, prescale);
return -EINVAL;
+ }
+
+ if (dc DUTY_CYCLE_HIGH_MIN) {
+ if (0 != duty_ns) {
+ dev_warn(chip-dev,
+ %s: pwm[%d]: duty cycle=%d is not
achievable, dc=%lu, prescale=%lu\n,
+ __func__, chan, duty_ns, dc, prescale);
+ }
+ return -EINVAL;
+ }
/* If pc and dc are in bounds, the calculation is done */
if (pc = PERIOD_COUNT_MAX dc = DUTY_CYCLE_HIGH_MAX)
break;
/* Otherwise, increase prescale and recalculate pc and dc */
- if (++prescale PRESCALE_MAX)
+ if (++prescale PRESCALE_MAX) {
+ dev_warn(chip-dev,
+ %s: pwm[%d]: Prescale (=%lu) within max (=%d)
for period=%d and duty cycle=%d is not achievable\n,
+ __func__, chan, prescale, PRESCALE_MAX,
+ period_ns, duty_ns);
return -EINVAL;
+ }
}
+ dev_dbg(chip-dev, pwm[%d]: period=%lu, duty_high=%lu, prescale=%lu\n,
+ chan, pc, dc, prescale);
+
/*
* Don't apply settings if disabled. The period and duty cycle are
* always calculated above to ensure the new values are
--
1.7.9.5
--
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the body of a message to majord...@vger.kernel.org
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