tjh.dev
Linux kernel mirror (for testing)
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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/mod_devicetable.h>
11#include <linux/rtc.h>
12#include <linux/platform_device.h>
13#include <linux/io.h>
14#include <linux/gfp.h>
15
16#define EP93XX_RTC_DATA 0x000
17#define EP93XX_RTC_MATCH 0x004
18#define EP93XX_RTC_STATUS 0x008
19#define EP93XX_RTC_STATUS_INTR BIT(0)
20#define EP93XX_RTC_LOAD 0x00C
21#define EP93XX_RTC_CONTROL 0x010
22#define EP93XX_RTC_CONTROL_MIE BIT(0)
23#define EP93XX_RTC_SWCOMP 0x108
24#define EP93XX_RTC_SWCOMP_DEL_MASK 0x001f0000
25#define EP93XX_RTC_SWCOMP_DEL_SHIFT 16
26#define EP93XX_RTC_SWCOMP_INT_MASK 0x0000ffff
27#define EP93XX_RTC_SWCOMP_INT_SHIFT 0
28
29struct ep93xx_rtc {
30 void __iomem *mmio_base;
31 struct rtc_device *rtc;
32};
33
34static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload,
35 unsigned short *delete)
36{
37 struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev);
38 unsigned long comp;
39
40 comp = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP);
41
42 if (preload)
43 *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK)
44 >> EP93XX_RTC_SWCOMP_INT_SHIFT;
45
46 if (delete)
47 *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK)
48 >> EP93XX_RTC_SWCOMP_DEL_SHIFT;
49
50 return 0;
51}
52
53static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm)
54{
55 struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev);
56 unsigned long time;
57
58 time = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA);
59
60 rtc_time64_to_tm(time, tm);
61 return 0;
62}
63
64static int ep93xx_rtc_set_time(struct device *dev, struct rtc_time *tm)
65{
66 struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev);
67 unsigned long secs = rtc_tm_to_time64(tm);
68
69 writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD);
70 return 0;
71}
72
73static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq)
74{
75 unsigned short preload, delete;
76
77 ep93xx_rtc_get_swcomp(dev, &preload, &delete);
78
79 seq_printf(seq, "preload\t\t: %d\n", preload);
80 seq_printf(seq, "delete\t\t: %d\n", delete);
81
82 return 0;
83}
84
85static const struct rtc_class_ops ep93xx_rtc_ops = {
86 .read_time = ep93xx_rtc_read_time,
87 .set_time = ep93xx_rtc_set_time,
88 .proc = ep93xx_rtc_proc,
89};
90
91static ssize_t comp_preload_show(struct device *dev,
92 struct device_attribute *attr, char *buf)
93{
94 unsigned short preload;
95
96 ep93xx_rtc_get_swcomp(dev->parent, &preload, NULL);
97
98 return sprintf(buf, "%d\n", preload);
99}
100static DEVICE_ATTR_RO(comp_preload);
101
102static ssize_t comp_delete_show(struct device *dev,
103 struct device_attribute *attr, char *buf)
104{
105 unsigned short delete;
106
107 ep93xx_rtc_get_swcomp(dev->parent, NULL, &delete);
108
109 return sprintf(buf, "%d\n", delete);
110}
111static DEVICE_ATTR_RO(comp_delete);
112
113static struct attribute *ep93xx_rtc_attrs[] = {
114 &dev_attr_comp_preload.attr,
115 &dev_attr_comp_delete.attr,
116 NULL
117};
118
119static const struct attribute_group ep93xx_rtc_sysfs_files = {
120 .attrs = ep93xx_rtc_attrs,
121};
122
123static int ep93xx_rtc_probe(struct platform_device *pdev)
124{
125 struct ep93xx_rtc *ep93xx_rtc;
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 ep93xx_rtc->mmio_base = devm_platform_ioremap_resource(pdev, 0);
133 if (IS_ERR(ep93xx_rtc->mmio_base))
134 return PTR_ERR(ep93xx_rtc->mmio_base);
135
136 platform_set_drvdata(pdev, ep93xx_rtc);
137
138 ep93xx_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
139 if (IS_ERR(ep93xx_rtc->rtc))
140 return PTR_ERR(ep93xx_rtc->rtc);
141
142 ep93xx_rtc->rtc->ops = &ep93xx_rtc_ops;
143 ep93xx_rtc->rtc->range_max = U32_MAX;
144
145 err = rtc_add_group(ep93xx_rtc->rtc, &ep93xx_rtc_sysfs_files);
146 if (err)
147 return err;
148
149 return devm_rtc_register_device(ep93xx_rtc->rtc);
150}
151
152static const struct of_device_id ep93xx_rtc_of_ids[] = {
153 { .compatible = "cirrus,ep9301-rtc" },
154 { /* sentinel */ }
155};
156MODULE_DEVICE_TABLE(of, ep93xx_rtc_of_ids);
157
158static struct platform_driver ep93xx_rtc_driver = {
159 .driver = {
160 .name = "ep93xx-rtc",
161 .of_match_table = ep93xx_rtc_of_ids,
162 },
163 .probe = ep93xx_rtc_probe,
164};
165
166module_platform_driver(ep93xx_rtc_driver);
167
168MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
169MODULE_DESCRIPTION("EP93XX RTC driver");
170MODULE_LICENSE("GPL");
171MODULE_ALIAS("platform:ep93xx-rtc");