Hi all,
Please give feedback on these patches which extends the PWM
framework in order to support multiple PWM signal types.
Since I didn't receive any inputs on RFC series I'm resending it as
normal patch series.
The current patch series add the following PWM signal types:
- PWM complementary signals
- PWM push-pull signal
Definition of PWM complementary mode:
For a PWM controllers with more than one outputs per PWM channel,
e.g. with 2 outputs per PWM channels, the PWM complementary signals
have opposite levels, same duration and same starting times,
as in the following diagram:
__ __ __ __
PWMH __| |__| |__| |__| |__
__ __ __ __ __
PWML |__| |__| |__| |__|
<--T-->
Where T is the signal period.
Definition of PWM push-pull mode:
For PWM controllers with more than one outputs per PWM channel,
e.g. with 2 outputs per PWM channel, the PWM push-pull signals
have same levels, same duration and are delayed until the begining
of the next period, as in the following diagram:
__ __
PWMH __| |________| |________
__ __
PWML ________| |________| |__
<--T-->
Where T is the signal period.
These output signals could be configured by setting PWM mode
(a new input in sysfs has been added in order to support this
operation).
root@sama5d2-xplained:/sys/devices/platform/ahb/ahb:apb/f802c000.pwm/pwm/pwmchip0/pwm2# ls -l
-r--r--r-- 1 root root 4096 Feb 9 10:54 capture
-rw-r--r-- 1 root root 4096 Feb 9 10:54 duty_cycle
-rw-r--r-- 1 root root 4096 Feb 9 10:54 enable
-rw-r--r-- 1 root root 4096 Feb 9 10:54 mode
-rw-r--r-- 1 root root 4096 Feb 9 10:54 period
-rw-r--r-- 1 root root 4096 Feb 9 10:55 polarity
drwxr-xr-x 2 root root 0 Feb 9 10:54 power
-rw-r--r-- 1 root root 4096 Feb 9 10:54 uevent
The PWM push-pull mode could be usefull in applications like
half bridge converters.
This series add support for PWM modes on atmel SAMA5D2 SoC.
Thank you,
Claudiu Beznea
Claudiu Beznea (2):
drivers: pwm: core: implement pwm mode
drivers: pwm: pwm-atmel: add support for pwm modes
Documentation/pwm.txt | 24 ++++++++--
drivers/pwm/core.c | 13 +++++-
drivers/pwm/pwm-atmel.c | 103 +++++++++++++++++++++++++++++-------------
drivers/pwm/sysfs.c | 52 +++++++++++++++++++++
include/dt-bindings/pwm/pwm.h | 1 +
include/linux/pwm.h | 37 ++++++++++++++-
6 files changed, 192 insertions(+), 38 deletions(-)
--
2.7.4
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