pwm-tipwmss.c
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/*
* TI PWM Subsystem driver
*
* Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/pm_runtime.h>
#include <linux/of_device.h>
#include "pwm-tipwmss.h"
#define PWMSS_CLKCONFIG 0x8 /* Clock gating reg */
#define PWMSS_CLKSTATUS 0xc /* Clock gating status reg */
struct pwmss_info {
void __iomem *mmio_base;
struct mutex pwmss_lock;
u16 pwmss_clkconfig;
};
u16 pwmss_submodule_state_change(struct device *dev, int set)
{
struct pwmss_info *info = dev_get_drvdata(dev);
u16 val;
mutex_lock(&info->pwmss_lock);
val = readw(info->mmio_base + PWMSS_CLKCONFIG);
val |= set;
writew(val , info->mmio_base + PWMSS_CLKCONFIG);
mutex_unlock(&info->pwmss_lock);
return readw(info->mmio_base + PWMSS_CLKSTATUS);
}
EXPORT_SYMBOL(pwmss_submodule_state_change);
static const struct of_device_id pwmss_of_match[] = {
{ .compatible = "ti,am33xx-pwmss" },
{},
};
MODULE_DEVICE_TABLE(of, pwmss_of_match);
static int pwmss_probe(struct platform_device *pdev)
{
int ret;
struct resource *r;
struct pwmss_info *info;
struct device_node *node = pdev->dev.of_node;
info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
if (!info) {
dev_err(&pdev->dev, "failed to allocate memory\n");
return -ENOMEM;
}
mutex_init(&info->pwmss_lock);
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
info->mmio_base = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(info->mmio_base))
return PTR_ERR(info->mmio_base);
pm_runtime_enable(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);
platform_set_drvdata(pdev, info);
/* Populate all the child nodes here... */
ret = of_platform_populate(node, NULL, NULL, &pdev->dev);
if (ret)
dev_err(&pdev->dev, "no child node found\n");
return ret;
}
static int pwmss_remove(struct platform_device *pdev)
{
struct pwmss_info *info = platform_get_drvdata(pdev);
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
mutex_destroy(&info->pwmss_lock);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int pwmss_suspend(struct device *dev)
{
struct pwmss_info *info = dev_get_drvdata(dev);
info->pwmss_clkconfig = readw(info->mmio_base + PWMSS_CLKCONFIG);
pm_runtime_put_sync(dev);
return 0;
}
static int pwmss_resume(struct device *dev)
{
struct pwmss_info *info = dev_get_drvdata(dev);
pm_runtime_get_sync(dev);
writew(info->pwmss_clkconfig, info->mmio_base + PWMSS_CLKCONFIG);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(pwmss_pm_ops, pwmss_suspend, pwmss_resume);
static struct platform_driver pwmss_driver = {
.driver = {
.name = "pwmss",
.owner = THIS_MODULE,
.pm = &pwmss_pm_ops,
.of_match_table = pwmss_of_match,
},
.probe = pwmss_probe,
.remove = pwmss_remove,
};
module_platform_driver(pwmss_driver);
MODULE_DESCRIPTION("PWM Subsystem driver");
MODULE_AUTHOR("Texas Instruments");
MODULE_LICENSE("GPL");