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		return -ENOMEM;
 67
 68	mutex_init(&info->pwmss_lock);
 69
 70	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 71	info->mmio_base = devm_ioremap_resource(&pdev->dev, r);
 72	if (IS_ERR(info->mmio_base))
 73		return PTR_ERR(info->mmio_base);
 74
 75	pm_runtime_enable(&pdev->dev);
 76	pm_runtime_get_sync(&pdev->dev);
 77	platform_set_drvdata(pdev, info);
 78
 79	/* Populate all the child nodes here... */
 80	ret = of_platform_populate(node, NULL, NULL, &pdev->dev);
 81	if (ret)
 82		dev_err(&pdev->dev, "no child node found\n");
 83
 84	return ret;
 85}
 86
 87static int pwmss_remove(struct platform_device *pdev)
 88{
 89	struct pwmss_info *info = platform_get_drvdata(pdev);
 90
 91	pm_runtime_put_sync(&pdev->dev);
 92	pm_runtime_disable(&pdev->dev);
 93	mutex_destroy(&info->pwmss_lock);
 94	return 0;
 95}
 96
 97#ifdef CONFIG_PM_SLEEP
 98static int pwmss_suspend(struct device *dev)
 99{
100	struct pwmss_info *info = dev_get_drvdata(dev);
101
102	info->pwmss_clkconfig = readw(info->mmio_base + PWMSS_CLKCONFIG);
103	pm_runtime_put_sync(dev);
104	return 0;
105}
106
107static int pwmss_resume(struct device *dev)
108{
109	struct pwmss_info *info = dev_get_drvdata(dev);
110
111	pm_runtime_get_sync(dev);
112	writew(info->pwmss_clkconfig, info->mmio_base + PWMSS_CLKCONFIG);
113	return 0;
114}
115#endif
116
117static SIMPLE_DEV_PM_OPS(pwmss_pm_ops, pwmss_suspend, pwmss_resume);
118
119static struct platform_driver pwmss_driver = {
120	.driver	= {
121		.name	= "pwmss",
122		.pm	= &pwmss_pm_ops,
123		.of_match_table	= pwmss_of_match,
124	},
125	.probe	= pwmss_probe,
126	.remove	= pwmss_remove,
127};
128
129module_platform_driver(pwmss_driver);
130
131MODULE_DESCRIPTION("PWM Subsystem driver");
132MODULE_AUTHOR("Texas Instruments");
133MODULE_LICENSE("GPL");