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>

diff --git a/drivers/Kconfig b/drivers/Kconfig
index c481e93356d6d3dac295cb0132ff274e34cf8874..70993fdab80f2e0985bcc802de695d9076fd28b4 100644 (file)
--- 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 (file)
index 0000000..bd47159
--- /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 c0c4883317378261e0eed47942e8ab2e254d4ef4..d1b15e5b11e1c8f0b1ef97172a89ffea2baf09de 100644 (file)
--- 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 (file)
index 0000000..c2200af
--- /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",
+};

diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index b5f43ae95e616912371a7751b0716f2207750384..8f0381d6e55ecb79413972c35940c53fc343e8cf 100644 (file)
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -51,6 +51,7 @@ enum uclass_id {
        UCLASS_PINCTRL,         /* Pinctrl (pin muxing/configuration) device */
        UCLASS_PINCONFIG,       /* Pin configuration node device */
        UCLASS_PMIC,            /* PMIC I/O device */
+       UCLASS_PWM,             /* Pulse-width modulator */
        UCLASS_PWRSEQ,          /* Power sequence device */
        UCLASS_REGULATOR,       /* Regulator device */
        UCLASS_RESET,           /* Reset device */

diff --git a/include/pwm.h b/include/pwm.h
index f24f2202f481a777e757fd9e8be286b4784ee627..851915eb87a6e253868bcbda25a2a09710a8c0a2 100644 (file)
--- a/include/pwm.h
+++ b/include/pwm.h
@@ -1,6 +1,7 @@
 /*
  * header file for pwm driver.
  *
+ * Copyright 2016 Google Inc.
  * Copyright (c) 2011 samsung electronics
  * Donghwa Lee <dh09.lee@samsung.com>
  *
@@ -10,9 +11,61 @@
 #ifndef _pwm_h_
 #define _pwm_h_
 
+/* struct pwm_ops: Operations for the PWM uclass */
+struct pwm_ops {
+       /**
+        * set_config() - Set the PWM configuration
+        *
+        * @dev:        PWM device to update
+        * @channel:    PWM channel to update
+        * @period_ns:  PWM period in nanoseconds
+        * @duty_ns:    PWM duty period in nanoseconds
+        * @return 0 if OK, -ve on error
+        */
+       int (*set_config)(struct udevice *dev, uint channel, uint period_ns,
+                         uint duty_ns);
+
+       /**
+        * set_enable() - Enable or disable the PWM
+        *
+        * @dev:        PWM device to update
+        * @channel:    PWM channel to update
+        * @enable:     true to enable, false to disable
+        * @return 0 if OK, -ve on error
+        */
+       int (*set_enable)(struct udevice *dev, uint channel, bool enable);
+};
+
+#define pwm_get_ops(dev)       ((struct pwm_ops *)(dev)->driver->ops)
+
+/**
+ * pwm_set_config() - Set the PWM configuration
+ *
+ * @dev:       PWM device to update
+ * @channel:   PWM channel to update
+ * @period_ns: PWM period in nanoseconds
+ * @duty_ns:   PWM duty period in nanoseconds
+ * @return 0 if OK, -ve on error
+ */
+int pwm_set_config(struct udevice *dev, uint channel, uint period_ns,
+                  uint duty_ns);
+
+/**
+ * pwm_set_enable() - Enable or disable the PWM
+ *
+ * @dev:       PWM device to update
+ * @channel:   PWM channel to update
+ * @enable:    true to enable, false to disable
+ * @return 0 if OK, -ve on error
+ */
+int pwm_set_enable(struct udevice *dev, uint channel, bool enable);
+
+/* Legacy interface */
+#ifndef CONFIG_DM_PWM
 int    pwm_init                (int pwm_id, int div, int invert);
 int    pwm_config              (int pwm_id, int duty_ns, int period_ns);
 int    pwm_enable              (int pwm_id);
 void   pwm_disable             (int pwm_id);
+#endif
 
 #endif /* _pwm_h_ */