Hi all, Please give feedback on these patches which extends PWM framework in order to support PWM dead-times. For a PWM controller with more than one output signals per PWM channel dead-times are the delays introduced between the edges of the output signals and the original signal introduced in dead-time generator engine. E.g. consider a PWM controller with with the following diagram: ----------------- | |---> PWMH PWM signal --->| Dead-time engine| | |---> PWML ----------------- With no dead-time configured, the PWMH and PWML signals will be complementary signals (rising and falling edges of PWMH and PWML have opposite leves, same duration and same starting time) as follows: ____0 D____P ____ ____ ____ PWM signal __| |____| |____| |____| |____| |___ ____ ____ ____ ____ ____ PWMH __| |____| |____| |____| |____| |___ __ ____ ____ ____ ____ ___ PWML |____| |____| |____| |____| |____| Where - 0 is the starting point of the signal - D is the starting point of the duty-cycle - P is the signal period Based on the above diagram: - rising edge dead-time - is the delay introduced in one of the dead-time engine output signal; the delay is introduced after rising edge of PWM signal - falling edge dead-time - is the delay introduced in one of the dead-time engine output signal; the delay is introduced after the end of falling edge of the PWM signal The following diagram explain how PWM dead-times falls on some signals: ____0 D____P ____ ____ ____ PWM signal __| |____| |____| |____| |____| |___ __ __ __ __ __ PWMH ____| |____re| |______| |______| |______| |___ __ __ __ __ __ __ PWML |______| |____fe| |______| |______| |______| In the upper diagram: - re = rising edge = the delay between D point of PWM signal (rising edge) and the starting point of the next edge - fe = falling edge = the delay between P point of PWM signal (falling edge) and the starting point of the next edge To configure the PWM dead-times new inputs were added to sysfs, in PWM subsystem, one for rising edge dead-time, one for falling edge deadtime. root@sama5d2-xplained:/sys/devices/platform/ahb/ahb:apb/f802c000.pwm/pwm/pwmchip0/pwm2# ls -l -r--r--r-- 1 root root 4096 Feb 10 10:00 capture -rw-r--r-- 1 root root 4096 Feb 10 10:01 deadtime_fe -rw-r--r-- 1 root root 4096 Feb 10 10:02 deadtime_re -rw-r--r-- 1 root root 4096 Feb 10 10:00 duty_cycle -rw-r--r-- 1 root root 4096 Feb 10 10:00 enable -rw-r--r-- 1 root root 4096 Feb 10 10:00 period -rw-r--r-- 1 root root 4096 Feb 10 10:00 polarity drwxr-xr-x 2 root root 0 Feb 10 10:00 power -rw-r--r-- 1 root root 4096 Feb 10 10:00 uevent The PWM dead-times are used in half bridge converters applications. Please consider that this series was build on top of following patch series: [PATCH v3 0/2] switch to atomic PWM [PATCH v3 1/2] drivers: pwm: pwm-atmel: switch to atomic PWM [PATCH v3 2/2] drivers: pwm: pwm-atmel: enable PWM on sama5d2 This patch series is not dependent on the other patch series I've made for extending PWM framework with PWM mode: [RFC PATCH 0/2] extend PWM framework to support PWM modes [RFC PATCH 1/2] drivers: pwm: core: implement pwm mode [RFC PATCH 2/2] drivers: pwm: pwm-atmel: add support for pwm modes but, if you consider relevant, and both patch changes are considered relevant for PWM subsistem, I can combine both of them, if any. Thanks you, Claudiu Beznea Claudiu Beznea (2): drivers: pwm: core: implement pwm dead-times drivers: pwm: pwm-atmel: implement pwm dead-time Documentation/pwm.txt | 52 ++++++++++++++++++++++++++++++++++ drivers/pwm/core.c | 10 ++++++- drivers/pwm/pwm-atmel.c | 56 ++++++++++++++++++++++++++++++++++--- drivers/pwm/sysfs.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/pwm.h | 36 ++++++++++++++++++++++++ 5 files changed, 223 insertions(+), 5 deletions(-) -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html