pwm: pwm-tiecap: PWM driver support for ECAP APWM

ECAP hardware on AM33XX SOC supports auxiliary PWM (APWM) feature. This
commit adds PWM driver support for ECAP hardware on AM33XX SOC.

In the ECAP hardware, each PWM pin can also be configured to be in
capture mode. Current implementation only supports PWM mode of
operation. Also, hardware supports sync between multiple PWM pins but
the driver supports simple independent PWM functionality.

Reviewed-by: Vaibhav Bedia <vaibhav.bedia@ti.com>
Signed-off-by: Philip, Avinash <avinashphilip@ti.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 94e176e..2b7db5d 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -76,6 +76,16 @@
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-tegra.
 
+config  PWM_TIECAP
+	tristate "ECAP PWM support"
+	depends on SOC_AM33XX
+	help
+	  PWM driver support for the ECAP APWM controller found on AM33XX
+	  TI SOC
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-tiecap.
+
 config PWM_VT8500
 	tristate "vt8500 pwm support"
 	depends on ARCH_VT8500