summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-ftrtc010.c
blob: 53bb08fe1cd462628d8dbedabdbed7f6fe7a15d3 (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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Faraday Technology FTRTC010 driver
 *
 *  Copyright (C) 2009 Janos Laube <janos.dev@gmail.com>
 *
 * Original code for older kernel 2.6.15 are from Stormlinksemi
 * first update from Janos Laube for > 2.6.29 kernels
 *
 * checkpatch fixes and usage of rtc-lib code
 * Hans Ulli Kroll <ulli.kroll@googlemail.com>
 */

#include <linux/rtc.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/clk.h>

#define DRV_NAME        "rtc-ftrtc010"

MODULE_AUTHOR("Hans Ulli Kroll <ulli.kroll@googlemail.com>");
MODULE_DESCRIPTION("RTC driver for Gemini SoC");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);

struct ftrtc010_rtc {
	struct rtc_device	*rtc_dev;
	void __iomem		*rtc_base;
	int			rtc_irq;
	struct clk		*pclk;
	struct clk		*extclk;
};

enum ftrtc010_rtc_offsets {
	FTRTC010_RTC_SECOND		= 0x00,
	FTRTC010_RTC_MINUTE		= 0x04,
	FTRTC010_RTC_HOUR		= 0x08,
	FTRTC010_RTC_DAYS		= 0x0C,
	FTRTC010_RTC_ALARM_SECOND	= 0x10,
	FTRTC010_RTC_ALARM_MINUTE	= 0x14,
	FTRTC010_RTC_ALARM_HOUR		= 0x18,
	FTRTC010_RTC_RECORD		= 0x1C,
	FTRTC010_RTC_CR			= 0x20,
};

static irqreturn_t ftrtc010_rtc_interrupt(int irq, void *dev)
{
	return IRQ_HANDLED;
}

/*
 * Looks like the RTC in the Gemini SoC is (totaly) broken
 * We can't read/write directly the time from RTC registers.
 * We must do some "offset" calculation to get the real time
 *
 * This FIX works pretty fine and Stormlinksemi aka Cortina-Networks does
 * the same thing, without the rtc-lib.c calls.
 */

static int ftrtc010_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct ftrtc010_rtc *rtc = dev_get_drvdata(dev);

	u32 days, hour, min, sec, offset;
	timeu64_t time;

	sec  = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);
	min  = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);
	hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);
	days = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);
	offset = readl(rtc->rtc_base + FTRTC010_RTC_RECORD);

	time = offset + days * 86400 + hour * 3600 + min * 60 + sec;

	rtc_time64_to_tm(time, tm);

	return 0;
}

static int ftrtc010_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct ftrtc010_rtc *rtc = dev_get_drvdata(dev);
	u32 sec, min, hour, day, offset;
	timeu64_t time;

	time = rtc_tm_to_time64(tm);

	sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);
	min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);
	hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);
	day = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);

	offset = time - (day * 86400 + hour * 3600 + min * 60 + sec);

	writel(offset, rtc->rtc_base + FTRTC010_RTC_RECORD);
	writel(0x01, rtc->rtc_base + FTRTC010_RTC_CR);

	return 0;
}

static const struct rtc_class_ops ftrtc010_rtc_ops = {
	.read_time     = ftrtc010_rtc_read_time,
	.set_time      = ftrtc010_rtc_set_time,
};

static int ftrtc010_rtc_probe(struct platform_device *pdev)
{
	u32 days, hour, min, sec;
	struct ftrtc010_rtc *rtc;
	struct device *dev = &pdev->dev;
	struct resource *res;
	int ret;

	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
	if (unlikely(!rtc))
		return -ENOMEM;
	platform_set_drvdata(pdev, rtc);

	rtc->pclk = devm_clk_get(dev, "PCLK");
	if (IS_ERR(rtc->pclk)) {
		dev_err(dev, "could not get PCLK\n");
	} else {
		ret = clk_prepare_enable(rtc->pclk);
		if (ret) {
			dev_err(dev, "failed to enable PCLK\n");
			return ret;
		}
	}
	rtc->extclk = devm_clk_get(dev, "EXTCLK");
	if (IS_ERR(rtc->extclk)) {
		dev_err(dev, "could not get EXTCLK\n");
	} else {
		ret = clk_prepare_enable(rtc->extclk);
		if (ret) {
			dev_err(dev, "failed to enable EXTCLK\n");
			return ret;
		}
	}

	rtc->rtc_irq = platform_get_irq(pdev, 0);
	if (rtc->rtc_irq < 0)
		return rtc->rtc_irq;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENODEV;

	rtc->rtc_base = devm_ioremap(dev, res->start,
				     resource_size(res));
	if (!rtc->rtc_base)
		return -ENOMEM;

	rtc->rtc_dev = devm_rtc_allocate_device(dev);
	if (IS_ERR(rtc->rtc_dev))
		return PTR_ERR(rtc->rtc_dev);

	rtc->rtc_dev->ops = &ftrtc010_rtc_ops;

	sec  = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);
	min  = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);
	hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);
	days = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);

	rtc->rtc_dev->range_min = (u64)days * 86400 + hour * 3600 +
				  min * 60 + sec;
	rtc->rtc_dev->range_max = U32_MAX + rtc->rtc_dev->range_min;

	ret = devm_request_irq(dev, rtc->rtc_irq, ftrtc010_rtc_interrupt,
			       IRQF_SHARED, pdev->name, dev);
	if (unlikely(ret))
		return ret;

	return devm_rtc_register_device(rtc->rtc_dev);
}

static int ftrtc010_rtc_remove(struct platform_device *pdev)
{
	struct ftrtc010_rtc *rtc = platform_get_drvdata(pdev);

	if (!IS_ERR(rtc->extclk))
		clk_disable_unprepare(rtc->extclk);
	if (!IS_ERR(rtc->pclk))
		clk_disable_unprepare(rtc->pclk);

	return 0;
}

static const struct of_device_id ftrtc010_rtc_dt_match[] = {
	{ .compatible = "cortina,gemini-rtc" },
	{ .compatible = "faraday,ftrtc010" },
	{ }
};
MODULE_DEVICE_TABLE(of, ftrtc010_rtc_dt_match);

static struct platform_driver ftrtc010_rtc_driver = {
	.driver		= {
		.name	= DRV_NAME,
		.of_match_table = ftrtc010_rtc_dt_match,
	},
	.probe		= ftrtc010_rtc_probe,
	.remove		= ftrtc010_rtc_remove,
};

module_platform_driver_probe(ftrtc010_rtc_driver, ftrtc010_rtc_probe);