1/*
2 * Copyright (c) 2011 Zhao Zhang <zhzhl555@gmail.com>
3 *
4 * Derived from driver/rtc/rtc-au1xxx.c
5 *
6 * This program is free software; you can redistribute  it and/or modify it
7 * under  the terms of  the GNU General  Public License as published by the
8 * Free Software Foundation;  either version 2 of the  License, or (at your
9 * option) any later version.
10 */
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/rtc.h>
15#include <linux/init.h>
16#include <linux/platform_device.h>
17#include <linux/delay.h>
18#include <linux/types.h>
19#include <linux/io.h>
20#include <loongson1.h>
21
22#define LS1X_RTC_REG_OFFSET	(LS1X_RTC_BASE + 0x20)
23#define LS1X_RTC_REGS(x) \
24		((void __iomem *)KSEG1ADDR(LS1X_RTC_REG_OFFSET + (x)))
25
26/*RTC programmable counters 0 and 1*/
27#define SYS_COUNTER_CNTRL		(LS1X_RTC_REGS(0x20))
28#define SYS_CNTRL_ERS			(1 << 23)
29#define SYS_CNTRL_RTS			(1 << 20)
30#define SYS_CNTRL_RM2			(1 << 19)
31#define SYS_CNTRL_RM1			(1 << 18)
32#define SYS_CNTRL_RM0			(1 << 17)
33#define SYS_CNTRL_RS			(1 << 16)
34#define SYS_CNTRL_BP			(1 << 14)
35#define SYS_CNTRL_REN			(1 << 13)
36#define SYS_CNTRL_BRT			(1 << 12)
37#define SYS_CNTRL_TEN			(1 << 11)
38#define SYS_CNTRL_BTT			(1 << 10)
39#define SYS_CNTRL_E0			(1 << 8)
40#define SYS_CNTRL_ETS			(1 << 7)
41#define SYS_CNTRL_32S			(1 << 5)
42#define SYS_CNTRL_TTS			(1 << 4)
43#define SYS_CNTRL_TM2			(1 << 3)
44#define SYS_CNTRL_TM1			(1 << 2)
45#define SYS_CNTRL_TM0			(1 << 1)
46#define SYS_CNTRL_TS			(1 << 0)
47
48/* Programmable Counter 0 Registers */
49#define SYS_TOYTRIM		(LS1X_RTC_REGS(0))
50#define SYS_TOYWRITE0		(LS1X_RTC_REGS(4))
51#define SYS_TOYWRITE1		(LS1X_RTC_REGS(8))
52#define SYS_TOYREAD0		(LS1X_RTC_REGS(0xC))
53#define SYS_TOYREAD1		(LS1X_RTC_REGS(0x10))
54#define SYS_TOYMATCH0		(LS1X_RTC_REGS(0x14))
55#define SYS_TOYMATCH1		(LS1X_RTC_REGS(0x18))
56#define SYS_TOYMATCH2		(LS1X_RTC_REGS(0x1C))
57
58/* Programmable Counter 1 Registers */
59#define SYS_RTCTRIM		(LS1X_RTC_REGS(0x40))
60#define SYS_RTCWRITE0		(LS1X_RTC_REGS(0x44))
61#define SYS_RTCREAD0		(LS1X_RTC_REGS(0x48))
62#define SYS_RTCMATCH0		(LS1X_RTC_REGS(0x4C))
63#define SYS_RTCMATCH1		(LS1X_RTC_REGS(0x50))
64#define SYS_RTCMATCH2		(LS1X_RTC_REGS(0x54))
65
66#define LS1X_SEC_OFFSET		(4)
67#define LS1X_MIN_OFFSET		(10)
68#define LS1X_HOUR_OFFSET	(16)
69#define LS1X_DAY_OFFSET		(21)
70#define LS1X_MONTH_OFFSET	(26)
71
72
73#define LS1X_SEC_MASK		(0x3f)
74#define LS1X_MIN_MASK		(0x3f)
75#define LS1X_HOUR_MASK		(0x1f)
76#define LS1X_DAY_MASK		(0x1f)
77#define LS1X_MONTH_MASK		(0x3f)
78#define LS1X_YEAR_MASK		(0xffffffff)
79
80#define ls1x_get_sec(t)		(((t) >> LS1X_SEC_OFFSET) & LS1X_SEC_MASK)
81#define ls1x_get_min(t)		(((t) >> LS1X_MIN_OFFSET) & LS1X_MIN_MASK)
82#define ls1x_get_hour(t)	(((t) >> LS1X_HOUR_OFFSET) & LS1X_HOUR_MASK)
83#define ls1x_get_day(t)		(((t) >> LS1X_DAY_OFFSET) & LS1X_DAY_MASK)
84#define ls1x_get_month(t)	(((t) >> LS1X_MONTH_OFFSET) & LS1X_MONTH_MASK)
85
86#define RTC_CNTR_OK (SYS_CNTRL_E0 | SYS_CNTRL_32S)
87
88static int ls1x_rtc_read_time(struct device *dev, struct rtc_time *rtm)
89{
90	unsigned long v, t;
91
92	v = readl(SYS_TOYREAD0);
93	t = readl(SYS_TOYREAD1);
94
95	memset(rtm, 0, sizeof(struct rtc_time));
96	t  = mktime((t & LS1X_YEAR_MASK), ls1x_get_month(v),
97			ls1x_get_day(v), ls1x_get_hour(v),
98			ls1x_get_min(v), ls1x_get_sec(v));
99	rtc_time_to_tm(t, rtm);
100
101	return rtc_valid_tm(rtm);
102}
103
104static int ls1x_rtc_set_time(struct device *dev, struct  rtc_time *rtm)
105{
106	unsigned long v, t, c;
107	int ret = -ETIMEDOUT;
108
109	v = ((rtm->tm_mon + 1)  << LS1X_MONTH_OFFSET)
110		| (rtm->tm_mday << LS1X_DAY_OFFSET)
111		| (rtm->tm_hour << LS1X_HOUR_OFFSET)
112		| (rtm->tm_min  << LS1X_MIN_OFFSET)
113		| (rtm->tm_sec  << LS1X_SEC_OFFSET);
114
115	writel(v, SYS_TOYWRITE0);
116	c = 0x10000;
117	/* add timeout check counter, for more safe */
118	while ((readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TS) && --c)
119		usleep_range(1000, 3000);
120
121	if (!c) {
122		dev_err(dev, "set time timeout!\n");
123		goto err;
124	}
125
126	t = rtm->tm_year + 1900;
127	writel(t, SYS_TOYWRITE1);
128	c = 0x10000;
129	while ((readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TS) && --c)
130		usleep_range(1000, 3000);
131
132	if (!c) {
133		dev_err(dev, "set time timeout!\n");
134		goto err;
135	}
136	return 0;
137err:
138	return ret;
139}
140
141static struct rtc_class_ops  ls1x_rtc_ops = {
142	.read_time	= ls1x_rtc_read_time,
143	.set_time	= ls1x_rtc_set_time,
144};
145
146static int ls1x_rtc_probe(struct platform_device *pdev)
147{
148	struct rtc_device *rtcdev;
149	unsigned long v;
150	int ret;
151
152	v = readl(SYS_COUNTER_CNTRL);
153	if (!(v & RTC_CNTR_OK)) {
154		dev_err(&pdev->dev, "rtc counters not working\n");
155		ret = -ENODEV;
156		goto err;
157	}
158	ret = -ETIMEDOUT;
159	/* set to 1 HZ if needed */
160	if (readl(SYS_TOYTRIM) != 32767) {
161		v = 0x100000;
162		while ((readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TTS) && --v)
163			usleep_range(1000, 3000);
164
165		if (!v) {
166			dev_err(&pdev->dev, "time out\n");
167			goto err;
168		}
169		writel(32767, SYS_TOYTRIM);
170	}
171	/* this loop coundn't be endless */
172	while (readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TTS)
173		usleep_range(1000, 3000);
174
175	rtcdev = devm_rtc_device_register(&pdev->dev, "ls1x-rtc",
176					&ls1x_rtc_ops , THIS_MODULE);
177	if (IS_ERR(rtcdev)) {
178		ret = PTR_ERR(rtcdev);
179		goto err;
180	}
181
182	platform_set_drvdata(pdev, rtcdev);
183	return 0;
184err:
185	return ret;
186}
187
188static struct platform_driver  ls1x_rtc_driver = {
189	.driver		= {
190		.name	= "ls1x-rtc",
191	},
192	.probe		= ls1x_rtc_probe,
193};
194
195module_platform_driver(ls1x_rtc_driver);
196
197MODULE_AUTHOR("zhao zhang <zhzhl555@gmail.com>");
198MODULE_LICENSE("GPL");
199