1/*
  2 * TI PWM Subsystem driver
  3 *
  4 * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License as published by
  8 * the Free Software Foundation; either version 2 of the License, or
  9 * (at your option) any later version.
 10 *
 11 * This program is distributed in the hope that it will be useful,
 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 14 * GNU General Public License for more details.
 15 *
 16 */
 17
 18#include <linux/module.h>
 19#include <linux/platform_device.h>
 20#include <linux/io.h>
 21#include <linux/err.h>
 22#include <linux/pm_runtime.h>
 23#include <linux/of_device.h>
 24
 25#include "pwm-tipwmss.h"
 26
 27#define PWMSS_CLKCONFIG		0x8	/* Clock gating reg */
 28#define PWMSS_CLKSTATUS		0xc	/* Clock gating status reg */
 29
 30struct pwmss_info {
 31	void __iomem	*mmio_base;
 32	struct mutex	pwmss_lock;
 33	u16		pwmss_clkconfig;
 34};
 35
 36u16 pwmss_submodule_state_change(struct device *dev, int set)
 37{
 38	struct pwmss_info *info = dev_get_drvdata(dev);
 39	u16 val;
 40
 41	mutex_lock(&info->pwmss_lock);
 42	val = readw(info->mmio_base + PWMSS_CLKCONFIG);
 43	val |= set;
 44	writew(val , info->mmio_base + PWMSS_CLKCONFIG);
 45	mutex_unlock(&info->pwmss_lock);
 46
 47	return readw(info->mmio_base + PWMSS_CLKSTATUS);
 48}
 49EXPORT_SYMBOL(pwmss_submodule_state_change);
 50
 51static const struct of_device_id pwmss_of_match[] = {
 52	{ .compatible	= "ti,am33xx-pwmss" },
 53	{},
 54};
 55MODULE_DEVICE_TABLE(of, pwmss_of_match);
 56
 57static int pwmss_probe(struct platform_device *pdev)
 58{
 59	int ret;
 60	struct resource *r;
 61	struct pwmss_info *info;
 62	struct device_node *node = pdev->dev.of_node;
 63
 64	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
 65	if (!info) {
 66		dev_err(&pdev->dev, "failed to allocate memory\n");
 67		return -ENOMEM;
 68	}
 69
 70	mutex_init(&info->pwmss_lock);
 71
 72	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 73	info->mmio_base = devm_ioremap_resource(&pdev->dev, r);
 74	if (IS_ERR(info->mmio_base))
 75		return PTR_ERR(info->mmio_base);
 76
 77	pm_runtime_enable(&pdev->dev);
 78	pm_runtime_get_sync(&pdev->dev);
 79	platform_set_drvdata(pdev, info);
 80
 81	/* Populate all the child nodes here... */
 82	ret = of_platform_populate(node, NULL, NULL, &pdev->dev);
 83	if (ret)
 84		dev_err(&pdev->dev, "no child node found\n");
 85
 86	return ret;
 87}
 88
 89static int pwmss_remove(struct platform_device *pdev)
 90{
 91	struct pwmss_info *info = platform_get_drvdata(pdev);
 92
 93	pm_runtime_put_sync(&pdev->dev);
 94	pm_runtime_disable(&pdev->dev);
 95	mutex_destroy(&info->pwmss_lock);
 96	return 0;
 97}
 98
 99#ifdef CONFIG_PM_SLEEP
100static int pwmss_suspend(struct device *dev)
101{
102	struct pwmss_info *info = dev_get_drvdata(dev);
103
104	info->pwmss_clkconfig = readw(info->mmio_base + PWMSS_CLKCONFIG);
105	pm_runtime_put_sync(dev);
106	return 0;
107}
108
109static int pwmss_resume(struct device *dev)
110{
111	struct pwmss_info *info = dev_get_drvdata(dev);
112
113	pm_runtime_get_sync(dev);
114	writew(info->pwmss_clkconfig, info->mmio_base + PWMSS_CLKCONFIG);
115	return 0;
116}
117#endif
118
119static SIMPLE_DEV_PM_OPS(pwmss_pm_ops, pwmss_suspend, pwmss_resume);
120
121static struct platform_driver pwmss_driver = {
122	.driver	= {
123		.name	= "pwmss",
124		.owner	= THIS_MODULE,
125		.pm	= &pwmss_pm_ops,
126		.of_match_table	= pwmss_of_match,
127	},
128	.probe	= pwmss_probe,
129	.remove	= pwmss_remove,
130};
131
132module_platform_driver(pwmss_driver);
133
134MODULE_DESCRIPTION("PWM Subsystem driver");
135MODULE_AUTHOR("Texas Instruments");
136MODULE_LICENSE("GPL");