summaryrefslogtreecommitdiffstats
path: root/drivers/pwm/pwm-tipwmss.c
blob: 5cf65a15d02191b3b8400713133470d5bcc303f8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
/*
 * 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)
		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",
		.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");