blob: 17cbc59660ec44fc2f1e31f51414d5fe43fd186c [file] [log] [blame]
Philip, Avinashaf0ba002012-11-27 14:18:06 +05301/*
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 if (!r) {
74 dev_err(&pdev->dev, "no memory resource defined\n");
75 return -ENODEV;
76 }
77
Thierry Reding6d4294d2013-01-21 11:09:16 +010078 info->mmio_base = devm_ioremap_resource(&pdev->dev, r);
79 if (IS_ERR(info->mmio_base))
80 return PTR_ERR(info->mmio_base);
Philip, Avinashaf0ba002012-11-27 14:18:06 +053081
82 pm_runtime_enable(&pdev->dev);
83 pm_runtime_get_sync(&pdev->dev);
84 platform_set_drvdata(pdev, info);
85
86 /* Populate all the child nodes here... */
87 ret = of_platform_populate(node, NULL, NULL, &pdev->dev);
88 if (ret)
89 dev_err(&pdev->dev, "no child node found\n");
90
91 return ret;
92}
93
94static int pwmss_remove(struct platform_device *pdev)
95{
96 struct pwmss_info *info = platform_get_drvdata(pdev);
97
98 pm_runtime_put_sync(&pdev->dev);
99 pm_runtime_disable(&pdev->dev);
100 mutex_destroy(&info->pwmss_lock);
101 return 0;
102}
103
104static int pwmss_suspend(struct device *dev)
105{
106 struct pwmss_info *info = dev_get_drvdata(dev);
107
108 info->pwmss_clkconfig = readw(info->mmio_base + PWMSS_CLKCONFIG);
109 pm_runtime_put_sync(dev);
110 return 0;
111}
112
113static int pwmss_resume(struct device *dev)
114{
115 struct pwmss_info *info = dev_get_drvdata(dev);
116
117 pm_runtime_get_sync(dev);
118 writew(info->pwmss_clkconfig, info->mmio_base + PWMSS_CLKCONFIG);
119 return 0;
120}
121
122static SIMPLE_DEV_PM_OPS(pwmss_pm_ops, pwmss_suspend, pwmss_resume);
123
124static struct platform_driver pwmss_driver = {
125 .driver = {
126 .name = "pwmss",
127 .owner = THIS_MODULE,
128 .pm = &pwmss_pm_ops,
129 .of_match_table = pwmss_of_match,
130 },
131 .probe = pwmss_probe,
132 .remove = pwmss_remove,
133};
134
135module_platform_driver(pwmss_driver);
136
137MODULE_DESCRIPTION("PWM Subsystem driver");
138MODULE_AUTHOR("Texas Instruments");
139MODULE_LICENSE("GPL");