Hi,
On Sat, Apr 17, 2021 at 05:37:28PM +0200, Uwe Kleine-König wrote:
> On Mon, Apr 12, 2021 at 03:27:38PM +0200, Clemens Gruber wrote:
> > The switch to the atomic API goes hand in hand with a few fixes to
> > previously experienced issues:
> > - The duty cycle is no long
On Fri, Apr 16, 2021 at 03:55:11PM +0200, Thierry Reding wrote:
> On Mon, Apr 12, 2021 at 03:27:41PM +0200, Clemens Gruber wrote:
> > Add the flag and corresponding documentation for PWM_USAGE_POWER.
> >
> > Cc: Rob Herring
> > Signed-off-by: Clemens Gruber
> >
Regmap operations can fail if the underlying subsystem is not working
properly (e.g. hogged I2C bus, etc.)
As this is useful information for the user, print an error message if it
happens.
Let probe fail if the first regmap_read or the first regmap_write fails.
Signed-off-by: Clemens Gruber
the chosen periods must match.
GPIOs do not count as enabled PWMs as they are not using the prescaler
and can't change it.
Signed-off-by: Clemens Gruber
---
Changes since v8:
- Rebased
Changes since v7:
- As the HW readout always returns enabled, also set the pwms_enabled
bit in request
-by: Clemens Gruber
---
Changes since v8:
- Improved readability of failed regmap_read
- Rebased
drivers/pwm/pwm-pca9685.c | 65 ++-
1 file changed, 50 insertions(+), 15 deletions(-)
diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c
index 1b013d03f5d8
Add the flag and corresponding documentation for PWM_USAGE_POWER.
Cc: Rob Herring
Signed-off-by: Clemens Gruber
---
Documentation/devicetree/bindings/pwm/pwm.txt | 3 +++
include/dt-bindings/pwm/pwm.h | 1 +
2 files changed, 4 insertions(+)
diff --git a/Documentation
If the flag PWM_USAGE_POWER is set on a channel, the PWM driver may
optimize the signal as long as the power output is not changed.
Depending on the specific driver, the optimization could for example
improve EMI (if supported) by phase-shifting the individual channels.
Signed-off-by: Clemens
The chip does not come out of POR in active state but in sleep state.
To be sure (in case the bootloader woke it up) we force it to sleep in
probe.
If runtime PM is disabled, we instead wake the chip in .probe and put it
to sleep in .remove.
Signed-off-by: Clemens Gruber
---
Changes since v8
frequency when using the internal 25 MHz oscillator, the calculated
period from the default prescaler register setting of 30 is 5079040ns.
Signed-off-by: Clemens Gruber
---
Changes since v8:
- As we left the math in apply as-is, use DIV_ROUND_DOWN in get_state
Changes since v7:
- Always return
, which is not allowed according
to the datasheet
- The OFF registers were reset to 0 in probe, which could lead to the
forbidden on=0, off=0. Fixed by resetting to POR default (full OFF)
Signed-off-by: Clemens Gruber
---
Changes since v8:
- Revert to DIV_ROUND_UP (keep math as-is)
- Readability
On Wed, Apr 14, 2021 at 09:21:31PM +0200, Uwe Kleine-König wrote:
> On Wed, Apr 14, 2021 at 02:09:14PM +0200, Clemens Gruber wrote:
> > Hi Uwe,
> >
> > On Tue, Apr 13, 2021 at 09:38:18PM +0200, Uwe Kleine-König wrote:
> > > Hello Clemens,
> > >
> &g
Hi Uwe,
On Tue, Apr 13, 2021 at 09:38:18PM +0200, Uwe Kleine-König wrote:
> Hello Clemens,
>
> On Tue, Apr 13, 2021 at 02:11:38PM +0200, Clemens Gruber wrote:
> > On Mon, Apr 12, 2021 at 10:10:19PM +0200, Uwe Kleine-König wrote:
> > > On Mon, Apr 12, 2021 at 06:39:28
On Tue, Apr 13, 2021 at 02:37:50PM +0200, Thierry Reding wrote:
> On Tue, Apr 13, 2021 at 02:11:38PM +0200, Clemens Gruber wrote:
> > Hi Uwe,
> >
> > On Mon, Apr 12, 2021 at 10:10:19PM +0200, Uwe Kleine-König wrote:
> > > Hello Clemens,
> > >
> &g
On Tue, Apr 13, 2021 at 02:11:38PM +0200, Clemens Gruber wrote:
> Hi Uwe,
>
> On Mon, Apr 12, 2021 at 10:10:19PM +0200, Uwe Kleine-König wrote:
> > Hello Clemens,
> >
> > On Mon, Apr 12, 2021 at 06:39:28PM +0200, Clemens Gruber wrote:
> > > On Mon, Apr 12,
Hi Uwe,
On Mon, Apr 12, 2021 at 10:10:19PM +0200, Uwe Kleine-König wrote:
> Hello Clemens,
>
> On Mon, Apr 12, 2021 at 06:39:28PM +0200, Clemens Gruber wrote:
> > On Mon, Apr 12, 2021 at 06:18:08PM +0200, Uwe Kleine-König wrote:
> > > On Mon, Apr 12, 2021 at 03:27:38
Hi,
On Mon, Apr 12, 2021 at 06:30:45PM +0200, Uwe Kleine-König wrote:
> On Mon, Apr 12, 2021 at 03:27:43PM +0200, Clemens Gruber wrote:
> > If PWM_USAGE_POWER is set on a PWM, the pca9685 driver will phase shift
> > the individual channels relative to their channel number. This i
On Mon, Apr 12, 2021 at 06:27:23PM +0200, Uwe Kleine-König wrote:
> On Mon, Apr 12, 2021 at 03:27:41PM +0200, Clemens Gruber wrote:
> > Add the flag and corresponding documentation for PWM_USAGE_POWER.
>
> My concern here in the previous round was that PWM_USAGE_POWER
Hi Uwe,
On Mon, Apr 12, 2021 at 06:18:08PM +0200, Uwe Kleine-König wrote:
> Hello Clemens,
>
> On Mon, Apr 12, 2021 at 03:27:38PM +0200, Clemens Gruber wrote:
> > The switch to the atomic API goes hand in hand with a few fixes to
> > previously experienced issues:
If the flag PWM_USAGE_POWER is set on a channel, the PWM driver may
optimize the signal as long as the power output is not changed.
Depending on the specific driver, the optimization could for example
improve EMI (if supported) by phase-shifting the individual channels.
Signed-off-by: Clemens
-by: Clemens Gruber
---
drivers/pwm/pwm-pca9685.c | 63 ++-
1 file changed, 49 insertions(+), 14 deletions(-)
diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c
index 7f97965033e7..410b93b115dc 100644
--- a/drivers/pwm/pwm-pca9685.c
+++ b/drivers/pwm
Add the flag and corresponding documentation for PWM_USAGE_POWER.
Cc: Rob Herring
Signed-off-by: Clemens Gruber
---
Documentation/devicetree/bindings/pwm/pwm.txt | 3 +++
include/dt-bindings/pwm/pwm.h | 1 +
2 files changed, 4 insertions(+)
diff --git a/Documentation
frequency when using the internal 25 MHz oscillator, the calculated
period from the default prescaler register setting of 30 is 5079040ns.
Signed-off-by: Clemens Gruber
---
Changes since v7:
- Always return enabled=true for channels except "all LEDs" channel
- Use DIV_ROUND_UP in .get_stat
, which is not allowed according
to the datasheet
- The OFF registers were reset to 0 in probe, which could lead to the
forbidden on=0, off=0. Fixed by resetting to POR default (full OFF)
Signed-off-by: Clemens Gruber
---
Changes since v7:
- Moved check for !state->enabled before presca
the chosen periods must match.
GPIOs do not count as enabled PWMs as they are not using the prescaler
and can't change it.
Signed-off-by: Clemens Gruber
---
Changes since v7:
- As the HW readout always returns enabled, also set the pwms_enabled
bit in request (except for the "all LEDs&quo
Regmap operations can fail if the underlying subsystem is not working
properly (e.g. hogged I2C bus, etc.)
As this is useful information for the user, print an error message if it
happens.
Let probe fail if the first regmap_read or the first regmap_write fails.
Signed-off-by: Clemens Gruber
The chip does not come out of POR in active state but in sleep state.
To be sure (in case the bootloader woke it up) we force it to sleep in
probe.
If runtime PM is disabled, we instead wake the chip in .probe and put it
to sleep in .remove.
Signed-off-by: Clemens Gruber
---
Changes since v7
On Fri, Apr 09, 2021 at 03:03:20PM +0200, Thierry Reding wrote:
> On Tue, Apr 06, 2021 at 06:41:35PM +0200, Clemens Gruber wrote:
> > The chip does not come out of POR in active state but in sleep state.
> > To be sure (in case the bootloader woke it up) we force it to sle
On Fri, Apr 09, 2021 at 01:25:36PM +0200, Thierry Reding wrote:
> On Thu, Apr 08, 2021 at 07:36:37PM +0200, Uwe Kleine-König wrote:
> > On Thu, Apr 08, 2021 at 05:51:36PM +0200, Clemens Gruber wrote:
> > > On Thu, Apr 08, 2021 at 02:50:40PM +0200, Thierry Reding wrote:
> >
On Thu, Apr 08, 2021 at 07:36:37PM +0200, Uwe Kleine-König wrote:
> On Thu, Apr 08, 2021 at 05:51:36PM +0200, Clemens Gruber wrote:
> > On Thu, Apr 08, 2021 at 02:50:40PM +0200, Thierry Reding wrote:
> > > Yes, I think that's basically what this is saying. I think we're perhaps
On Thu, Apr 08, 2021 at 02:50:40PM +0200, Thierry Reding wrote:
> On Wed, Apr 07, 2021 at 11:34:03PM +0200, Uwe Kleine-König wrote:
> > On Wed, Apr 07, 2021 at 10:21:10PM +0200, Clemens Gruber wrote:
> > > On Wed, Apr 07, 2021 at 07:46:58AM +0200, Uwe Kleine-König wrote:
>
On Wed, Apr 07, 2021 at 08:16:19AM +0200, Uwe Kleine-König wrote:
> On Tue, Apr 06, 2021 at 06:41:40PM +0200, Clemens Gruber wrote:
> > Regmap operations can fail if the underlying subsystem is not working
> > properly (e.g. hogged I2C bus, etc.)
> > As this is useful inf
On Wed, Apr 07, 2021 at 08:12:29AM +0200, Uwe Kleine-König wrote:
> On Tue, Apr 06, 2021 at 06:41:39PM +0200, Clemens Gruber wrote:
> > Previously, the last used PWM channel could change the global prescale
> > setting, even if other channels are already in use.
> >
> &
On Wed, Apr 07, 2021 at 07:46:58AM +0200, Uwe Kleine-König wrote:
> On Tue, Apr 06, 2021 at 06:41:37PM +0200, Clemens Gruber wrote:
> > If the flag PWM_STAGGERING_ALLOWED is set on a channel, the PWM driver
> > may (if supported by the HW) delay the ON time of the c
On Wed, Apr 07, 2021 at 11:09:43AM +0200, Uwe Kleine-König wrote:
> On Wed, Apr 07, 2021 at 09:33:20AM +0200, Clemens Gruber wrote:
> > On Wed, Apr 07, 2021 at 07:31:35AM +0200, Uwe Kleine-König wrote:
> > > On Tue, Apr 06, 2021 at 06:41:34PM +0200, Clemens Gruber wrote:
On Wed, Apr 07, 2021 at 07:31:35AM +0200, Uwe Kleine-König wrote:
> On Tue, Apr 06, 2021 at 06:41:34PM +0200, Clemens Gruber wrote:
> > Implements .get_state to read-out the current hardware state.
> >
> > The hardware readout may return slightly different values than th
Hi,
On Wed, Apr 07, 2021 at 07:24:28AM +0200, Uwe Kleine-König wrote:
> Hello,
>
> On Tue, Apr 06, 2021 at 06:41:33PM +0200, Clemens Gruber wrote:
> > The switch to the atomic API goes hand in hand with a few fixes to
> > previously experienced issues:
> > - The d
Regmap operations can fail if the underlying subsystem is not working
properly (e.g. hogged I2C bus, etc.)
As this is useful information for the user, print an error message if it
happens.
Let probe fail if the first regmap_read or the first regmap_write fails.
Signed-off-by: Clemens Gruber
the chosen periods must match.
GPIOs do not count as enabled PWMs as they are not using the prescaler
and can't change it.
Signed-off-by: Clemens Gruber
---
Changes since v6:
- Only allow the first PWM that is enabled to change the prescaler, not
the first one that uses the prescaler
drivers
still
maintaining the configured duty cycle of each output.
Signed-off-by: Clemens Gruber
---
Changes since v6:
- Use a per-PWM flag instead of one global DT parameter
drivers/pwm/pwm-pca9685.c | 60 ++-
1 file changed, 46 insertions(+), 14 deletions(-)
diff
assert
multiple or even all enabled channels at the same time.
If this feature is supported by the driver and the flag is set on
multiple channels, their ON times are spread out to improve EMI and
reduce current spikes.
Signed-off-by: Clemens Gruber
---
drivers/pwm/core.c | 9
Add the flag and corresponding documentation for the new PWM staggering
mode feature.
Cc: Rob Herring
Signed-off-by: Clemens Gruber
---
Documentation/devicetree/bindings/pwm/pwm.txt | 1 +
include/dt-bindings/pwm/pwm.h | 1 +
2 files changed, 2 insertions(+)
diff --git
The chip does not come out of POR in active state but in sleep state.
To be sure (in case the bootloader woke it up) we force it to sleep in
probe.
On kernels without CONFIG_PM, we wake the chip in .probe and put it to
sleep in .remove.
Signed-off-by: Clemens Gruber
---
Changes since v6
frequency when using the internal 25 MHz oscillator, the calculated
period from the default prescaler register setting of 30 is 5079040ns.
Signed-off-by: Clemens Gruber
---
Changes since v6:
- Added a comment regarding the division (Suggested by Uwe)
- Rebased
drivers/pwm/pwm-pca9685.c | 46
sets a period resulting in the same prescale register value,
the sleep and write to the register is now skipped
Signed-off-by: Clemens Gruber
---
Changes since v6:
- Order of a comparison switched for improved readability
Changes since v5:
- Function documentation for set_duty
- Variable
On Thu, Apr 01, 2021 at 10:59:36PM +0200, Uwe Kleine-König wrote:
> On Wed, Mar 31, 2021 at 03:55:49PM +0200, Clemens Gruber wrote:
> > On Wed, Mar 31, 2021 at 02:26:14PM +0200, Clemens Gruber wrote:
> > > On Mon, Mar 29, 2021 at 08:02:06PM +0200, Uwe Kleine-König wrote:
>
Hello Uwe,
On Thu, Apr 01, 2021 at 10:58:19PM +0200, Uwe Kleine-König wrote:
> Hello Clemens,
>
> On Wed, Mar 31, 2021 at 02:26:14PM +0200, Clemens Gruber wrote:
> > On Mon, Mar 29, 2021 at 08:02:06PM +0200, Uwe Kleine-König wrote:
> > > On Mon, Mar 29, 2021 at 07:16:38
On Thu, Apr 01, 2021 at 03:47:26PM +0200, Thierry Reding wrote:
> On Thu, Apr 01, 2021 at 09:50:44AM +0200, Clemens Gruber wrote:
> > Hi Thierry,
> >
> > On Wed, Mar 31, 2021 at 06:21:32PM +0200, Thierry Reding wrote:
> > > On Wed, Mar 31, 2021 at 02:26:14
Hi Thierry,
On Wed, Mar 31, 2021 at 06:21:32PM +0200, Thierry Reding wrote:
> On Wed, Mar 31, 2021 at 02:26:14PM +0200, Clemens Gruber wrote:
> > On Mon, Mar 29, 2021 at 08:02:06PM +0200, Uwe Kleine-König wrote:
> > > On Mon, Mar 29, 2021 at 07:16:38PM +0200, Clemens Gruber wro
On Wed, Mar 31, 2021 at 02:26:14PM +0200, Clemens Gruber wrote:
> On Mon, Mar 29, 2021 at 08:02:06PM +0200, Uwe Kleine-König wrote:
> > On Mon, Mar 29, 2021 at 07:16:38PM +0200, Clemens Gruber wrote:
> > > On Mon, Mar 29, 2021 at 07:03:57PM +0200, Uwe Kleine-König wrote:
>
On Mon, Mar 29, 2021 at 08:02:06PM +0200, Uwe Kleine-König wrote:
> On Mon, Mar 29, 2021 at 07:16:38PM +0200, Clemens Gruber wrote:
> > On Mon, Mar 29, 2021 at 07:03:57PM +0200, Uwe Kleine-König wrote:
> > > On Mon, Mar 29, 2021 at 02:57:04PM +0200, Clemens Gruber wrote:
&
On Mon, Mar 29, 2021 at 07:15:59PM +0200, Uwe Kleine-König wrote:
> On Mon, Mar 29, 2021 at 02:57:06PM +0200, Clemens Gruber wrote:
> > @@ -330,14 +345,22 @@ static int pca9685_pwm_apply(struct pwm_chip *chip,
> > struct pwm_device *pwm,
> >
> > if (
On Mon, Mar 29, 2021 at 07:03:57PM +0200, Uwe Kleine-König wrote:
> On Mon, Mar 29, 2021 at 02:57:04PM +0200, Clemens Gruber wrote:
> > The PCA9685 supports staggered LED output ON times to minimize current
> > surges and reduce EMI.
> > When this new option is enabled,
On Mon, Mar 29, 2021 at 06:54:29PM +0200, Uwe Kleine-König wrote:
> On Mon, Mar 29, 2021 at 02:57:02PM +0200, Clemens Gruber wrote:
> > Implements .get_state to read-out the current hardware state.
> >
> > The hardware readout may return slightly different values than th
Hi Uwe,
On Mon, Mar 29, 2021 at 05:51:40PM +0200, Uwe Kleine-König wrote:
> Hello Clemens,
>
> On Mon, Mar 29, 2021 at 02:57:02PM +0200, Clemens Gruber wrote:
> > The hardware readout may return slightly different values than those
> > that were set in apply due to the limi
Hi Uwe,
On Mon, Mar 29, 2021 at 05:55:27PM +0200, Uwe Kleine-König wrote:
> On Mon, Mar 29, 2021 at 02:57:03PM +0200, Clemens Gruber wrote:
> > The chip does not come out of POR in active state but in sleep state.
> > To be sure (in case the bootloader woke it up) we fo
resulting from the chosen periods must match.
PWMs that are disabled or have a duty cycle of 0% or 100% are not
considered to be using the prescaler as they have the full OFF or full
ON bits set. This also applies to channels used as GPIOs.
Signed-off-by: Clemens Gruber
---
Changes since v5:
- Reused
The pca9685 driver supports a new nxp,staggered-outputs property for
reduced current surges and EMI. This adds documentation for the new DT
property.
Signed-off-by: Clemens Gruber
---
Documentation/devicetree/bindings/pwm/nxp,pca9685-pwm.txt | 2 ++
1 file changed, 2 insertions(+)
diff --git
maintaining
the configured duty cycle of each output.
Signed-off-by: Clemens Gruber
---
Changes since v5:
- Simplified staggered outputs special case in set/get_duty
drivers/pwm/pwm-pca9685.c | 58 +--
1 file changed, 44 insertions(+), 14 deletions(-)
diff --git
Regmap operations can fail if the underlying subsystem is not working
properly (e.g. hogged I2C bus, etc.)
As this is useful information for the user, print an error message if it
happens.
Let probe fail if the first regmap_read or the first regmap_write fails.
Signed-off-by: Clemens Gruber
The chip does not come out of POR in active state but in sleep state.
To be sure (in case the bootloader woke it up) we force it to sleep in
probe.
On kernels without CONFIG_PM, we wake the chip in .probe and put it to
sleep in .remove.
Signed-off-by: Clemens Gruber
---
drivers/pwm/pwm-pca9685
frequency when using the internal 25 MHz oscillator, the calculated
period from the default prescaler register setting of 30 is 5079040ns.
Signed-off-by: Clemens Gruber
---
drivers/pwm/pwm-pca9685.c | 41 +++
1 file changed, 41 insertions(+)
diff --git a/drivers
sets a period resulting in the same prescale register value,
the sleep and write to the register is now skipped
Signed-off-by: Clemens Gruber
---
Changes since v5:
- Function documentation for set_duty
- Variable initializations
- Print warning if all LEDs channel
- Changed EOPNOTSUPP to EINVAL
Hi Thierry,
On Mon, Mar 22, 2021 at 10:19:22AM +0100, Thierry Reding wrote:
> On Fri, Jan 29, 2021 at 09:37:47PM +0100, Clemens Gruber wrote:
> > Hi Sven,
> >
> > On Fri, Jan 29, 2021 at 01:05:14PM -0500, Sven Van Asbroeck wrote:
> > > Hi Clemens,
> > >
Hi Thierry,
On Mon, Mar 22, 2021 at 08:58:35AM +0100, Thierry Reding wrote:
> On Thu, Dec 17, 2020 at 12:10:10PM -0500, Sven Van Asbroeck wrote:
> > On Thu, Dec 17, 2020 at 11:48 AM Clemens Gruber
> > wrote:
> > >
> > > I can initialize the values to 0 of co
Hi Uwe,
On Mon, Mar 01, 2021 at 10:52:48PM +0100, Uwe Kleine-König wrote:
> Hello,
>
> On Mon, Feb 01, 2021 at 06:24:02PM +0100, Clemens Gruber wrote:
> > Hi Sven, Thierry, Uwe,
> >
> > On Fri, Jan 29, 2021 at 05:16:51PM -0500, Sven Van Asbroeck wrote:
> > >
On Mon, Mar 01, 2021 at 10:46:33PM +0100, Uwe Kleine-König wrote:
> Hello Clemens,
>
> On Tue, Dec 15, 2020 at 10:22:25PM +0100, Clemens Gruber wrote:
> > Reset the prescale and ON/OFF registers to their POR default state in
> > the probe function. Otherwise, the PWMs could
Hi Uwe,
On Mon, Mar 01, 2021 at 10:44:07PM +0100, Uwe Kleine-König wrote:
> Hello Clemens,
>
> On Tue, Dec 15, 2020 at 10:22:22PM +0100, Clemens Gruber wrote:
> > + if (state->polarity != PWM_POLARITY_NORMAL)
> > + return -EOPNOTSUPP;
>
> We agreed
Hi Uwe,
On Mon, Mar 01, 2021 at 10:41:15PM +0100, Uwe Kleine-König wrote:
> On Thu, Dec 17, 2020 at 12:10:10PM -0500, Sven Van Asbroeck wrote:
> > On Thu, Dec 17, 2020 at 11:48 AM Clemens Gruber
> > wrote:
> > >
> > > I can initialize the values to 0 of co
Hi all,
On Fri, Jan 29, 2021 at 09:37:47PM +0100, Clemens Gruber wrote:
> Hi Sven,
>
> On Fri, Jan 29, 2021 at 01:05:14PM -0500, Sven Van Asbroeck wrote:
> > Hi Clemens,
> >
> > On Fri, Jan 29, 2021 at 11:31 AM Clemens Gruber
> > wrote:
> > >
> &
Hi Sven, Thierry, Uwe,
On Fri, Jan 29, 2021 at 05:16:51PM -0500, Sven Van Asbroeck wrote:
> Hi Clemens,
>
> On Fri, Jan 29, 2021 at 4:24 PM Sven Van Asbroeck wrote:
> >
> > LEN_ON = 409, LED_OFF = 1228 and
> > LED_ON = 419, LED_OFF = 1238
> > produ
Hi Sven,
On Fri, Jan 29, 2021 at 01:05:14PM -0500, Sven Van Asbroeck wrote:
> Hi Clemens,
>
> On Fri, Jan 29, 2021 at 11:31 AM Clemens Gruber
> wrote:
> >
> > Ok, so you suggest we extend our get_state logic to deal with cases
> > like the following:
>
>
r all we've learnt that the pca9685
> looks simple on the surface, but is actually quite challenging to get right.
>
> Clemens, Uwe, what do you think?
Ok, so you suggest we extend our get_state logic to deal with cases
like the following:
If neither full OFF nor full ON is set &
Hi,
On Mon, Jan 11, 2021 at 09:35:32PM +0100, Uwe Kleine-König wrote:
> Hello,
>
> On Thu, Dec 17, 2020 at 06:43:04PM +0100, Clemens Gruber wrote:
> > On Wed, Dec 16, 2020 at 11:00:59PM -0500, Sven Van Asbroeck wrote:
> > > On Wed, Dec 16, 2020 at 7:53 AM Cle
Hi everyone,
happy new year, hope you are all well!
On Thu, Dec 17, 2020 at 12:52:42PM -0500, Sven Van Asbroeck wrote:
> On Thu, Dec 17, 2020 at 12:43 PM Clemens Gruber
> wrote:
> > >
> > > Conclusion: .get_state() will always return "pwm disabled", so why do w
Hi Sven,
On Wed, Dec 16, 2020 at 11:03:39PM -0500, Sven Van Asbroeck wrote:
> Hi Clemens, see below.
>
> On Wed, Dec 16, 2020 at 7:53 AM Clemens Gruber
> wrote:
> >
> > Previously, the last used PWM channel could change the global prescale
> > setting, even if othe
On Wed, Dec 16, 2020 at 11:02:57PM -0500, Sven Van Asbroeck wrote:
> Hi Clemens, see below.
>
> On Wed, Dec 16, 2020 at 7:53 AM Clemens Gruber
> wrote:
> >
> > The PCA9685 supports staggered LED output ON times to minimize current
> > surges and reduce EMI.
>
On Wed, Dec 16, 2020 at 11:02:03PM -0500, Sven Van Asbroeck wrote:
> Hi Clemens, minor nit below.
>
> On Wed, Dec 16, 2020 at 7:53 AM Clemens Gruber
> wrote:
> >
> > Reset the prescale and ON/OFF registers to their POR default state in
> > the probe function. O
On Wed, Dec 16, 2020 at 11:00:59PM -0500, Sven Van Asbroeck wrote:
> On Wed, Dec 16, 2020 at 7:53 AM Clemens Gruber
> wrote:
> >
> > Implements .get_state to read-out the current hardware state.
> >
>
> I am not convinced that we actually need this.
>
>
Hi Sven,
On Wed, Dec 16, 2020 at 10:58:07PM -0500, Sven Van Asbroeck wrote:
> Hi Clemens, this looks compact, simple and neat. I like it a lot !!
Thanks!
>
> Few very minor nits below.
>
> On Wed, Dec 16, 2020 at 7:53 AM Clemens Gruber
> wrote:
> >
> > The swit
resulting from the chosen periods must match.
PWMs that are disabled or have a duty cycle of 0% or 100% are not
considered to be using the prescaler as they have the full OFF or full
ON bits set. This also applies to channels used as GPIOs.
Signed-off-by: Clemens Gruber
---
drivers/pwm/pwm-pca9685.c
The pca9685 driver supports a new nxp,staggered-outputs property for
reduced current surges and EMI. This adds documentation for the new DT
property.
Signed-off-by: Clemens Gruber
---
Documentation/devicetree/bindings/pwm/nxp,pca9685-pwm.txt | 2 ++
1 file changed, 2 insertions(+)
diff --git
maintaining
the configured duty cycle of each output.
Signed-off-by: Clemens Gruber
---
drivers/pwm/pwm-pca9685.c | 62 +++
1 file changed, 50 insertions(+), 12 deletions(-)
diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c
index 38aadaf50996
The chip does not come out of POR in active state but in sleep state.
To be sure (in case the bootloader woke it up) we force it to sleep in
probe.
On kernels without CONFIG_PM, we wake the chip in .probe and put it to
sleep in .remove.
Signed-off-by: Clemens Gruber
---
drivers/pwm/pwm-pca9685
Reset the prescale and ON/OFF registers to their POR default state in
the probe function. Otherwise, the PWMs could still be active after a
watchdog reset and reboot, etc.
Signed-off-by: Clemens Gruber
---
drivers/pwm/pwm-pca9685.c | 9 +++--
1 file changed, 7 insertions(+), 2 deletions
frequency when using the internal 25 MHz oscillator, the calculated
period from the default prescaler register setting of 30 is 5079040ns.
Signed-off-by: Clemens Gruber
---
drivers/pwm/pwm-pca9685.c | 41 +++
1 file changed, 41 insertions(+)
diff --git a/drivers
sets a period resulting in the same prescale register value,
the sleep and write to the register is now skipped
Signed-off-by: Clemens Gruber
---
Changes since v4:
- Patches split up
- Use a single set_duty function
- Improve readability / new macros
- Added a patch to restrict prescale changes
pstream and for some reason just
> haven't gotten around to it.
>
> On the other hand, almost 18-24 months without activity is quite long. A
> compromise that works well for me is to keep drivers, even unused ones,
> as long as they're not getting in the way.
>
> &
full-on or full-off
> PWM. It would still be a PWM, but just with additional restrictions
> on the duty cycle.
>
> 2) Use one channel as full PWM and the other channel as GPIO.
>
> 2) is a subset of 1) because we can implement 2) using 1) by treating
>
e duty cycle
is 0% or 100%.
>
> > > We can of course make this much simpler by assumung that gpio or on/off
> > > pwms
> > > are actually using the prescaler. But then we'd be limiting this chip's
> > > functionality.
> >
> > Yeah, this is obviously much simpler, but the cost is a bit high, in my
> > opinion. I'm fine with this alternative if there aren't any use-cases
> > where multiple outputs are actually used.
>
> This metric is wishy-washy; of course you can construct a use-case. I'd
> still go for this simpler option and assume the prescaler used if the
> PWM runs at 0% or 100%, but not when it is a GPIO.
I'd also prefer this solution.
Thanks,
Clemens
Hello Uwe,
On Tue, Dec 08, 2020 at 10:10:33AM +0100, Uwe Kleine-König wrote:
> Hello Clemens,
>
> On Tue, Dec 08, 2020 at 12:13:44AM +0100, Clemens Gruber wrote:
> > On Mon, Dec 07, 2020 at 11:00:25PM +0100, Uwe Kleine-König wrote:
> > > On Mon, Dec 07, 2020 at 08:36:27
Hi Sven,
On Mon, Dec 07, 2020 at 06:22:08PM -0500, Sven Van Asbroeck wrote:
> Hi Clemens, see below.
>
> On Mon, Dec 7, 2020 at 2:37 PM Clemens Gruber
> wrote:
> >
> > The switch to the atomic API goes hand in hand with a few fixes to
> > previously experience
in step 5 as well. So, only the
first consumer is allowed to change the period and only as long as it is
the only one that is in use / was requested.
But that's definitely a breaking change.
Thanks,
Clemens
On Mon, Dec 07, 2020 at 11:00:25PM +0100, Uwe Kleine-König wrote:
> On Mon, Dec 07, 2020 at 08:36:27PM +0100, Clemens Gruber wrote:
> > The switch to the atomic API goes hand in hand with a few fixes to
> > previously experienced issues:
> > - The duty cycle is no longer lost
still clear the rest of the OFF regs but now we set the
full OFF bit to avoid having both OFF and ON registers set to 0 and
start up in a safe default state.
Signed-off-by: Clemens Gruber
---
Changes since v1:
- Rebased
drivers/pwm/pwm-pca9685.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions
The pca9685 driver supports a new nxp,staggered-outputs property for
reduced current surges and EMI. This adds documentation for the new DT
property.
Signed-off-by: Clemens Gruber
---
Changes since v1:
- Added vendor prefix
Documentation/devicetree/bindings/pwm/nxp,pca9685-pwm.txt | 2 ++
1
frequency changed. (The PCA9685 has only one prescaler!)
Note that although the datasheet mentions 200 Hz as default frequency
when using the internal 25 MHz oscillator, the calculated period from
the default prescaler register setting of 30 is 5079040ns.
Signed-off-by: Clemens Gruber
---
Changes
maintaining
the configured duty cycle of each output.
Signed-off-by: Clemens Gruber
---
Changes since v3:
- Refactoring: Extracted common functions
- Fixed error in .get_state
- Added vendor prefix to DT property
Changes since v1:
- Rebased
drivers/pwm/pwm-pca9685.c | 72
Hi Sven,
On Wed, Nov 25, 2020 at 10:04:32AM -0500, Sven Van Asbroeck wrote:
> On Wed, Nov 25, 2020 at 3:35 AM Clemens Gruber
> wrote:
> >
> > >
> > > The datasheet I found for this chip indicates that every ALL_LED_XXX
> > > register
> > > is writ
On Wed, Nov 25, 2020 at 09:35:08AM +0100, Clemens Gruber wrote:
> On Tue, Nov 24, 2020 at 10:49:27PM -0500, Sven Van Asbroeck wrote:
> > Hi Clemens, I checked the patch against the datasheet register definitions.
> > More constructive feedback below.
> >
> > On T
On Tue, Nov 24, 2020 at 10:51:23PM -0500, Sven Van Asbroeck wrote:
> On Tue, Nov 24, 2020 at 1:10 PM Clemens Gruber
> wrote:
> >
> > The PCA9685 supports staggered LED output ON times to minimize current
> > surges and reduce EMI.
> > When this new option is enabled
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