GNU Linux-libre 4.4.289-gnu1
[releases.git] / drivers / rtc / rtc-ep93xx.c
1 /*
2  * A driver for the RTC embedded in the Cirrus Logic EP93XX processors
3  * Copyright (c) 2006 Tower Technologies
4  *
5  * Author: Alessandro Zummo <a.zummo@towertech.it>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11
12 #include <linux/module.h>
13 #include <linux/rtc.h>
14 #include <linux/platform_device.h>
15 #include <linux/io.h>
16 #include <linux/gfp.h>
17
18 #define EP93XX_RTC_DATA                 0x000
19 #define EP93XX_RTC_MATCH                0x004
20 #define EP93XX_RTC_STATUS               0x008
21 #define  EP93XX_RTC_STATUS_INTR          (1<<0)
22 #define EP93XX_RTC_LOAD                 0x00C
23 #define EP93XX_RTC_CONTROL              0x010
24 #define  EP93XX_RTC_CONTROL_MIE          (1<<0)
25 #define EP93XX_RTC_SWCOMP               0x108
26 #define  EP93XX_RTC_SWCOMP_DEL_MASK      0x001f0000
27 #define  EP93XX_RTC_SWCOMP_DEL_SHIFT     16
28 #define  EP93XX_RTC_SWCOMP_INT_MASK      0x0000ffff
29 #define  EP93XX_RTC_SWCOMP_INT_SHIFT     0
30
31 #define DRV_VERSION "0.3"
32
33 /*
34  * struct device dev.platform_data is used to store our private data
35  * because struct rtc_device does not have a variable to hold it.
36  */
37 struct ep93xx_rtc {
38         void __iomem    *mmio_base;
39         struct rtc_device *rtc;
40 };
41
42 static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload,
43                                 unsigned short *delete)
44 {
45         struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev);
46         unsigned long comp;
47
48         comp = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP);
49
50         if (preload)
51                 *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK)
52                                 >> EP93XX_RTC_SWCOMP_INT_SHIFT;
53
54         if (delete)
55                 *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK)
56                                 >> EP93XX_RTC_SWCOMP_DEL_SHIFT;
57
58         return 0;
59 }
60
61 static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm)
62 {
63         struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev);
64         unsigned long time;
65
66          time = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA);
67
68         rtc_time_to_tm(time, tm);
69         return 0;
70 }
71
72 static int ep93xx_rtc_set_mmss(struct device *dev, unsigned long secs)
73 {
74         struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev);
75
76         writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD);
77         return 0;
78 }
79
80 static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq)
81 {
82         unsigned short preload, delete;
83
84         ep93xx_rtc_get_swcomp(dev, &preload, &delete);
85
86         seq_printf(seq, "preload\t\t: %d\n", preload);
87         seq_printf(seq, "delete\t\t: %d\n", delete);
88
89         return 0;
90 }
91
92 static const struct rtc_class_ops ep93xx_rtc_ops = {
93         .read_time      = ep93xx_rtc_read_time,
94         .set_mmss       = ep93xx_rtc_set_mmss,
95         .proc           = ep93xx_rtc_proc,
96 };
97
98 static ssize_t ep93xx_rtc_show_comp_preload(struct device *dev,
99                         struct device_attribute *attr, char *buf)
100 {
101         unsigned short preload;
102
103         ep93xx_rtc_get_swcomp(dev, &preload, NULL);
104
105         return sprintf(buf, "%d\n", preload);
106 }
107 static DEVICE_ATTR(comp_preload, S_IRUGO, ep93xx_rtc_show_comp_preload, NULL);
108
109 static ssize_t ep93xx_rtc_show_comp_delete(struct device *dev,
110                         struct device_attribute *attr, char *buf)
111 {
112         unsigned short delete;
113
114         ep93xx_rtc_get_swcomp(dev, NULL, &delete);
115
116         return sprintf(buf, "%d\n", delete);
117 }
118 static DEVICE_ATTR(comp_delete, S_IRUGO, ep93xx_rtc_show_comp_delete, NULL);
119
120 static struct attribute *ep93xx_rtc_attrs[] = {
121         &dev_attr_comp_preload.attr,
122         &dev_attr_comp_delete.attr,
123         NULL
124 };
125
126 static const struct attribute_group ep93xx_rtc_sysfs_files = {
127         .attrs  = ep93xx_rtc_attrs,
128 };
129
130 static int ep93xx_rtc_probe(struct platform_device *pdev)
131 {
132         struct ep93xx_rtc *ep93xx_rtc;
133         struct resource *res;
134         int err;
135
136         ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL);
137         if (!ep93xx_rtc)
138                 return -ENOMEM;
139
140         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
141         ep93xx_rtc->mmio_base = devm_ioremap_resource(&pdev->dev, res);
142         if (IS_ERR(ep93xx_rtc->mmio_base))
143                 return PTR_ERR(ep93xx_rtc->mmio_base);
144
145         pdev->dev.platform_data = ep93xx_rtc;
146         platform_set_drvdata(pdev, ep93xx_rtc);
147
148         ep93xx_rtc->rtc = devm_rtc_device_register(&pdev->dev,
149                                 pdev->name, &ep93xx_rtc_ops, THIS_MODULE);
150         if (IS_ERR(ep93xx_rtc->rtc)) {
151                 err = PTR_ERR(ep93xx_rtc->rtc);
152                 goto exit;
153         }
154
155         err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
156         if (err)
157                 goto exit;
158
159         return 0;
160
161 exit:
162         pdev->dev.platform_data = NULL;
163         return err;
164 }
165
166 static int ep93xx_rtc_remove(struct platform_device *pdev)
167 {
168         sysfs_remove_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
169         pdev->dev.platform_data = NULL;
170
171         return 0;
172 }
173
174 static struct platform_driver ep93xx_rtc_driver = {
175         .driver         = {
176                 .name   = "ep93xx-rtc",
177         },
178         .probe          = ep93xx_rtc_probe,
179         .remove         = ep93xx_rtc_remove,
180 };
181
182 module_platform_driver(ep93xx_rtc_driver);
183
184 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
185 MODULE_DESCRIPTION("EP93XX RTC driver");
186 MODULE_LICENSE("GPL");
187 MODULE_VERSION(DRV_VERSION);
188 MODULE_ALIAS("platform:ep93xx-rtc");