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>
This commit is contained in:
Simon Glass 2016-01-21 19:44:54 -07:00
parent d4bf91ada1
commit fc760cb8c4
6 changed files with 103 additions and 0 deletions

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@ -46,6 +46,8 @@ source "drivers/pinctrl/Kconfig"
source "drivers/power/Kconfig"
source "drivers/pwm/Kconfig"
source "drivers/ram/Kconfig"
source "drivers/remoteproc/Kconfig"

10
drivers/pwm/Kconfig Normal file
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@ -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.

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@ -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

36
drivers/pwm/pwm-uclass.c Normal file
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@ -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",
};

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@ -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 */

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@ -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_ */