Commit 57d78f3e authored Jun 11, 2018 by Vignesh R Committed by Greg Kroah-Hartman Sep 09, 2018

pwm: tiehrpwm: Fix disabling of output of PWMs

commit 38dabd91ff0bde33352ca3cc65ef515599b77a05 upstream.

pwm-tiehrpwm driver disables PWM output by putting it in low output
state via active AQCSFRC register in ehrpwm_pwm_disable(). But, the
AQCSFRC shadow register is not updated. Therefore, when shadow AQCSFRC
register is re-enabled in ehrpwm_pwm_enable() (say to enable second PWM
output), previous settings are lost as shadow register value is loaded
into active register. This results in things like PWMA getting enabled
automatically, when PWMB is enabled and vice versa. Fix this by
updating AQCSFRC shadow register as well during ehrpwm_pwm_disable().

Fixes: 19891b20 ("pwm: pwm-tiehrpwm: PWM driver support for EHRPWM")
Cc: stable@vger.kernel.org
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent dfd7543a

drivers/pwm/pwm-tiehrpwm.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -384,6 +384,8 @@ static void ehrpwm_pwm_disable(struct pwm_chip chip, struct pwm_device pwm)
		aqcsfrc_mask = AQCSFRC_CSFA_MASK;
		}

		/* Update shadow register first before modifying active register */
		ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
		/*
		* Changes to immediate action on Action Qualifier. This puts
		* Action Qualifier control on PWM output from next TBCLK