dm: pwm: Add a PWM uclass

Add a uclass that supports Pulse Width Modulation (PWM) devices. It
provides methods to enable/disable and configure the device.

Signed-off-by: Simon Glass <sjg@chromium.org>

4 files changed, 49 insertions, 0 deletions

diff --git a/drivers/Kconfig b/drivers/Kconfig
index c481e93356..70993fdab8 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -46,6 +46,8 @@ source "drivers/pinctrl/Kconfig"
 
 source "drivers/power/Kconfig"
 
+source "drivers/pwm/Kconfig"
+
 source "drivers/ram/Kconfig"
 
 source "drivers/remoteproc/Kconfig"
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
new file mode 100644
index 0000000000..bd47159860
--- /dev/null
+++ b/drivers/pwm/Kconfig
@@ -0,0 +1,10 @@
+config DM_PWM
+	bool "Enable support for pulse-width modulation devices (PWM)"
+	depends on DM
+	help
+	  A pulse-width modulator emits a pulse of varying width and provides
+	  control over the duty cycle (high and low time) of the signal. This
+	  is often used to control a voltage level. The more time the PWM
+	  spends in the 'high' state, the higher the voltage. The PWM's
+	  frequency/period can be controlled along with the proportion of that
+	  time that the signal is high.
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index c0c4883317..d1b15e5b11 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -10,4 +10,5 @@
 
 #ccflags-y += -DDEBUG
 
+obj-$(CONFIG_DM_PWM) += pwm-uclass.o
 obj-$(CONFIG_PWM_IMX) += pwm-imx.o pwm-imx-util.o
diff --git a/drivers/pwm/pwm-uclass.c b/drivers/pwm/pwm-uclass.c
new file mode 100644
index 0000000000..c2200af8a5
--- /dev/null
+++ b/drivers/pwm/pwm-uclass.c
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2016 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <pwm.h>
+
+int pwm_set_config(struct udevice *dev, uint channel, uint period_ns,
+		   uint duty_ns)
+{
+	struct pwm_ops *ops = pwm_get_ops(dev);
+
+	if (!ops->set_config)
+		return -ENOSYS;
+
+	return ops->set_config(dev, channel, period_ns, duty_ns);
+}
+
+int pwm_set_enable(struct udevice *dev, uint channel, bool enable)
+{
+	struct pwm_ops *ops = pwm_get_ops(dev);
+
+	if (!ops->set_enable)
+		return -ENOSYS;
+
+	return ops->set_enable(dev, channel, enable);
+}
+
+UCLASS_DRIVER(pwm) = {
+	.id		= UCLASS_PWM,
+	.name		= "pwm",
+};