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rtc-ls1x.c
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1 /*
2  * Copyright (c) 2011 Zhao Zhang <[email protected]>
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 <asm/mach-loongson1/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 
88 static 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 
104 static 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;
137 err:
138  return ret;
139 }
140 
141 static struct rtc_class_ops ls1x_rtc_ops = {
142  .read_time = ls1x_rtc_read_time,
143  .set_time = ls1x_rtc_set_time,
144 };
145 
146 static int __devinit 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 = rtc_device_register("ls1x-rtc", &pdev->dev,
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;
184 err:
185  return ret;
186 }
187 
188 static int __devexit ls1x_rtc_remove(struct platform_device *pdev)
189 {
190  struct rtc_device *rtcdev = platform_get_drvdata(pdev);
191 
192  rtc_device_unregister(rtcdev);
193  platform_set_drvdata(pdev, NULL);
194 
195  return 0;
196 }
197 
198 static struct platform_driver ls1x_rtc_driver = {
199  .driver = {
200  .name = "ls1x-rtc",
201  .owner = THIS_MODULE,
202  },
203  .remove = __devexit_p(ls1x_rtc_remove),
204  .probe = ls1x_rtc_probe,
205 };
206 
207 module_platform_driver(ls1x_rtc_driver);
208 
209 MODULE_AUTHOR("zhao zhang <[email protected]>");
210 MODULE_LICENSE("GPL");
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