pwm: NXP LPC18xx PWM/SCT driver

This commit adds support for NXP LPC18xx PWM/SCT.

NXP LPC SoCs family, which includes LPC18xx/LPC43xx, provides a State
Configurable Timer (SCT) which can be configured as a Pulse Width
Modulator. Other SoCs in that family may share the same hardware.

The PWM supports a total of 16 channels, but only 15 can be simultaneously
requested. There's only one period, global to all the channels, thus PWM
driver will refuse setting different values to it, unless there's only one
channel requested.

Signed-off-by: Ariel D'Alessandro <ariel@vanguardiasur.com.ar>
[thierry.reding@gmail.com: remove excessive padding of fields]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/Kconfig

@@ -173,6 +173,18 @@ config PWM_LP3943
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-lp3943.
 
+config PWM_LPC18XX_SCT
+	tristate "LPC18xx/43xx PWM/SCT support"
+	depends on ARCH_LPC18XX
+	help
+	  Generic PWM framework driver for NXP LPC18xx PWM/SCT which
+	  supports 16 channels.
+	  A maximum of 15 channels can be requested simultaneously and
+	  must have the same period.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-lpc18xx-sct.
+
 config PWM_LPC32XX
 	tristate "LPC32XX PWM support"
 	depends on ARCH_LPC32XX

drivers/pwm/Makefile

@@ -14,6 +14,7 @@ obj-$(CONFIG_PWM_IMG)		+= pwm-img.o
 obj-$(CONFIG_PWM_IMX)		+= pwm-imx.o
 obj-$(CONFIG_PWM_JZ4740)	+= pwm-jz4740.o
 obj-$(CONFIG_PWM_LP3943)	+= pwm-lp3943.o
+obj-$(CONFIG_PWM_LPC18XX_SCT)	+= pwm-lpc18xx-sct.o
 obj-$(CONFIG_PWM_LPC32XX)	+= pwm-lpc32xx.o
 obj-$(CONFIG_PWM_LPSS)		+= pwm-lpss.o
 obj-$(CONFIG_PWM_LPSS_PCI)	+= pwm-lpss-pci.o