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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * A driver for the RTC embedded in the Cirrus Logic EP93XX processors
4 * Copyright (c) 2006 Tower Technologies
5 *
6 * Author: Alessandro Zummo <a.zummo@towertech.it>
7 */
8
9#include <linux/module.h>
10#include <linux/rtc.h>
11#include <linux/platform_device.h>
12#include <linux/io.h>
13#include <linux/gfp.h>
14
15#define EP93XX_RTC_DATA 0x000
16#define EP93XX_RTC_MATCH 0x004
17#define EP93XX_RTC_STATUS 0x008
18#define EP93XX_RTC_STATUS_INTR BIT(0)
19#define EP93XX_RTC_LOAD 0x00C
20#define EP93XX_RTC_CONTROL 0x010
21#define EP93XX_RTC_CONTROL_MIE BIT(0)
22#define EP93XX_RTC_SWCOMP 0x108
23#define EP93XX_RTC_SWCOMP_DEL_MASK 0x001f0000
24#define EP93XX_RTC_SWCOMP_DEL_SHIFT 16
25#define EP93XX_RTC_SWCOMP_INT_MASK 0x0000ffff
26#define EP93XX_RTC_SWCOMP_INT_SHIFT 0
27
28struct ep93xx_rtc {
29 void __iomem *mmio_base;
30 struct rtc_device *rtc;
31};
32
33static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload,
34 unsigned short *delete)
35{
36 struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev);
37 unsigned long comp;
38
39 comp = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP);
40
41 if (preload)
42 *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK)
43 >> EP93XX_RTC_SWCOMP_INT_SHIFT;
44
45 if (delete)
46 *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK)
47 >> EP93XX_RTC_SWCOMP_DEL_SHIFT;
48
49 return 0;
50}
51
52static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm)
53{
54 struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev);
55 unsigned long time;
56
57 time = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA);
58
59 rtc_time64_to_tm(time, tm);
60 return 0;
61}
62
63static int ep93xx_rtc_set_time(struct device *dev, struct rtc_time *tm)
64{
65 struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev);
66 unsigned long secs = rtc_tm_to_time64(tm);
67
68 writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD);
69 return 0;
70}
71
72static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq)
73{
74 unsigned short preload, delete;
75
76 ep93xx_rtc_get_swcomp(dev, &preload, &delete);
77
78 seq_printf(seq, "preload\t\t: %d\n", preload);
79 seq_printf(seq, "delete\t\t: %d\n", delete);
80
81 return 0;
82}
83
84static const struct rtc_class_ops ep93xx_rtc_ops = {
85 .read_time = ep93xx_rtc_read_time,
86 .set_time = ep93xx_rtc_set_time,
87 .proc = ep93xx_rtc_proc,
88};
89
90static ssize_t comp_preload_show(struct device *dev,
91 struct device_attribute *attr, char *buf)
92{
93 unsigned short preload;
94
95 ep93xx_rtc_get_swcomp(dev->parent, &preload, NULL);
96
97 return sprintf(buf, "%d\n", preload);
98}
99static DEVICE_ATTR_RO(comp_preload);
100
101static ssize_t comp_delete_show(struct device *dev,
102 struct device_attribute *attr, char *buf)
103{
104 unsigned short delete;
105
106 ep93xx_rtc_get_swcomp(dev->parent, NULL, &delete);
107
108 return sprintf(buf, "%d\n", delete);
109}
110static DEVICE_ATTR_RO(comp_delete);
111
112static struct attribute *ep93xx_rtc_attrs[] = {
113 &dev_attr_comp_preload.attr,
114 &dev_attr_comp_delete.attr,
115 NULL
116};
117
118static const struct attribute_group ep93xx_rtc_sysfs_files = {
119 .attrs = ep93xx_rtc_attrs,
120};
121
122static int ep93xx_rtc_probe(struct platform_device *pdev)
123{
124 struct ep93xx_rtc *ep93xx_rtc;
125 struct resource *res;
126 int err;
127
128 ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL);
129 if (!ep93xx_rtc)
130 return -ENOMEM;
131
132 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
133 ep93xx_rtc->mmio_base = devm_ioremap_resource(&pdev->dev, res);
134 if (IS_ERR(ep93xx_rtc->mmio_base))
135 return PTR_ERR(ep93xx_rtc->mmio_base);
136
137 platform_set_drvdata(pdev, ep93xx_rtc);
138
139 ep93xx_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
140 if (IS_ERR(ep93xx_rtc->rtc))
141 return PTR_ERR(ep93xx_rtc->rtc);
142
143 ep93xx_rtc->rtc->ops = &ep93xx_rtc_ops;
144 ep93xx_rtc->rtc->range_max = U32_MAX;
145
146 err = rtc_add_group(ep93xx_rtc->rtc, &ep93xx_rtc_sysfs_files);
147 if (err)
148 return err;
149
150 return rtc_register_device(ep93xx_rtc->rtc);
151}
152
153static struct platform_driver ep93xx_rtc_driver = {
154 .driver = {
155 .name = "ep93xx-rtc",
156 },
157 .probe = ep93xx_rtc_probe,
158};
159
160module_platform_driver(ep93xx_rtc_driver);
161
162MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
163MODULE_DESCRIPTION("EP93XX RTC driver");
164MODULE_LICENSE("GPL");
165MODULE_ALIAS("platform:ep93xx-rtc");