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
30 struct pwmss_info {
31 void __iomem *mmio_base;
32 struct mutex pwmss_lock;
33 u16 pwmss_clkconfig;
34 };
35
pwmss_submodule_state_change(struct device * dev,int set)36 u16 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 }
49 EXPORT_SYMBOL(pwmss_submodule_state_change);
50
51 static const struct of_device_id pwmss_of_match[] = {
52 { .compatible = "ti,am33xx-pwmss" },
53 {},
54 };
55 MODULE_DEVICE_TABLE(of, pwmss_of_match);
56
pwmss_probe(struct platform_device * pdev)57 static 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
pwmss_remove(struct platform_device * pdev)89 static 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
pwmss_suspend(struct device * dev)100 static 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
pwmss_resume(struct device * dev)109 static 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
119 static SIMPLE_DEV_PM_OPS(pwmss_pm_ops, pwmss_suspend, pwmss_resume);
120
121 static 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
132 module_platform_driver(pwmss_driver);
133
134 MODULE_DESCRIPTION("PWM Subsystem driver");
135 MODULE_AUTHOR("Texas Instruments");
136 MODULE_LICENSE("GPL");
137