blob: 0f7adeb1944a8f1acd93cae653a4af6c709380b9 [file] [log] [blame]
Richard Purdiee842f1c2006-03-27 01:16:46 -08001/*
2 * Real Time Clock interface for StrongARM SA1x00 and XScale PXA2xx
3 *
4 * Copyright (c) 2000 Nils Faerber
5 *
6 * Based on rtc.c by Paul Gortmaker
7 *
8 * Original Driver by Nils Faerber <nils@kernelconcepts.de>
9 *
10 * Modifications from:
11 * CIH <cih@coventive.com>
Nicolas Pitre2f82af02009-09-14 03:25:28 -040012 * Nicolas Pitre <nico@fluxnic.net>
Richard Purdiee842f1c2006-03-27 01:16:46 -080013 * Andrew Christian <andrew.christian@hp.com>
14 *
15 * Converted to the RTC subsystem and Driver Model
16 * by Richard Purdie <rpurdie@rpsys.net>
17 *
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
22 */
23
24#include <linux/platform_device.h>
25#include <linux/module.h>
Haojian Zhuang8e8bbcb2012-02-23 23:36:37 +080026#include <linux/clk.h>
Richard Purdiee842f1c2006-03-27 01:16:46 -080027#include <linux/rtc.h>
28#include <linux/init.h>
29#include <linux/fs.h>
30#include <linux/interrupt.h>
Haojian Zhuang3888c092012-02-21 11:51:13 +080031#include <linux/slab.h>
Russell Kinga0164a52012-01-19 11:55:21 +000032#include <linux/string.h>
Haojian Zhuang8bec2e92012-03-05 19:26:42 +080033#include <linux/of.h>
Richard Purdiee842f1c2006-03-27 01:16:46 -080034#include <linux/pm.h>
Russell Kinga0164a52012-01-19 11:55:21 +000035#include <linux/bitops.h>
Rob Herring23019a72012-03-20 14:33:19 -050036#include <linux/io.h>
Richard Purdiee842f1c2006-03-27 01:16:46 -080037
Russell Kinga09e64f2008-08-05 16:14:15 +010038#include <mach/hardware.h>
Rob Herring905cdc82012-02-23 14:27:58 +010039#include <mach/irqs.h>
Richard Purdiee842f1c2006-03-27 01:16:46 -080040
Haojian Zhuang3888c092012-02-21 11:51:13 +080041#if defined(CONFIG_ARCH_PXA) || defined(CONFIG_ARCH_MMP)
Russell Kinga0164a52012-01-19 11:55:21 +000042#include <mach/regs-rtc.h>
43#endif
44
Marcelo Roberto Jimeneza404ad12010-10-18 22:33:53 +010045#define RTC_DEF_DIVIDER (32768 - 1)
Richard Purdiee842f1c2006-03-27 01:16:46 -080046#define RTC_DEF_TRIM 0
Haojian Zhuang3888c092012-02-21 11:51:13 +080047#define RTC_FREQ 1024
Richard Purdiee842f1c2006-03-27 01:16:46 -080048
Haojian Zhuang3888c092012-02-21 11:51:13 +080049struct sa1100_rtc {
50 spinlock_t lock;
51 int irq_1hz;
52 int irq_alarm;
53 struct rtc_device *rtc;
Haojian Zhuang8e8bbcb2012-02-23 23:36:37 +080054 struct clk *clk;
Haojian Zhuang3888c092012-02-21 11:51:13 +080055};
Richard Purdiee842f1c2006-03-27 01:16:46 -080056
David Howells7d12e782006-10-05 14:55:46 +010057static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id)
Richard Purdiee842f1c2006-03-27 01:16:46 -080058{
Haojian Zhuang3888c092012-02-21 11:51:13 +080059 struct sa1100_rtc *info = dev_get_drvdata(dev_id);
60 struct rtc_device *rtc = info->rtc;
Richard Purdiee842f1c2006-03-27 01:16:46 -080061 unsigned int rtsr;
62 unsigned long events = 0;
63
Haojian Zhuang3888c092012-02-21 11:51:13 +080064 spin_lock(&info->lock);
Richard Purdiee842f1c2006-03-27 01:16:46 -080065
Russell Kinga0164a52012-01-19 11:55:21 +000066 rtsr = RTSR;
Richard Purdiee842f1c2006-03-27 01:16:46 -080067 /* clear interrupt sources */
Russell Kinga0164a52012-01-19 11:55:21 +000068 RTSR = 0;
Marcelo Roberto Jimenez7decaa52010-10-18 22:35:54 +010069 /* Fix for a nasty initialization problem the in SA11xx RTSR register.
70 * See also the comments in sa1100_rtc_probe(). */
71 if (rtsr & (RTSR_ALE | RTSR_HZE)) {
72 /* This is the original code, before there was the if test
73 * above. This code does not clear interrupts that were not
74 * enabled. */
Russell Kinga0164a52012-01-19 11:55:21 +000075 RTSR = (RTSR_AL | RTSR_HZ) & (rtsr >> 2);
Marcelo Roberto Jimenez7decaa52010-10-18 22:35:54 +010076 } else {
77 /* For some reason, it is possible to enter this routine
78 * without interruptions enabled, it has been tested with
79 * several units (Bug in SA11xx chip?).
80 *
81 * This situation leads to an infinite "loop" of interrupt
82 * routine calling and as a result the processor seems to
83 * lock on its first call to open(). */
Russell Kinga0164a52012-01-19 11:55:21 +000084 RTSR = RTSR_AL | RTSR_HZ;
Marcelo Roberto Jimenez7decaa52010-10-18 22:35:54 +010085 }
Richard Purdiee842f1c2006-03-27 01:16:46 -080086
87 /* clear alarm interrupt if it has occurred */
88 if (rtsr & RTSR_AL)
89 rtsr &= ~RTSR_ALE;
Russell Kinga0164a52012-01-19 11:55:21 +000090 RTSR = rtsr & (RTSR_ALE | RTSR_HZE);
Richard Purdiee842f1c2006-03-27 01:16:46 -080091
92 /* update irq data & counter */
93 if (rtsr & RTSR_AL)
94 events |= RTC_AF | RTC_IRQF;
95 if (rtsr & RTSR_HZ)
96 events |= RTC_UF | RTC_IRQF;
97
Russell Kinga0164a52012-01-19 11:55:21 +000098 rtc_update_irq(rtc, 1, events);
Richard Purdiee842f1c2006-03-27 01:16:46 -080099
Haojian Zhuang3888c092012-02-21 11:51:13 +0800100 spin_unlock(&info->lock);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800101
102 return IRQ_HANDLED;
103}
104
Richard Purdiee842f1c2006-03-27 01:16:46 -0800105static int sa1100_rtc_open(struct device *dev)
106{
Haojian Zhuang3888c092012-02-21 11:51:13 +0800107 struct sa1100_rtc *info = dev_get_drvdata(dev);
108 struct rtc_device *rtc = info->rtc;
Richard Purdiee842f1c2006-03-27 01:16:46 -0800109 int ret;
110
Linus Torvalds34800592012-03-27 16:41:24 -0700111 ret = request_irq(info->irq_1hz, sa1100_rtc_interrupt, 0, "rtc 1Hz", dev);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800112 if (ret) {
Haojian Zhuang3888c092012-02-21 11:51:13 +0800113 dev_err(dev, "IRQ %d already in use.\n", info->irq_1hz);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800114 goto fail_ui;
115 }
Linus Torvalds34800592012-03-27 16:41:24 -0700116 ret = request_irq(info->irq_alarm, sa1100_rtc_interrupt, 0, "rtc Alrm", dev);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800117 if (ret) {
Haojian Zhuang3888c092012-02-21 11:51:13 +0800118 dev_err(dev, "IRQ %d already in use.\n", info->irq_alarm);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800119 goto fail_ai;
120 }
Russell Kinga0164a52012-01-19 11:55:21 +0000121 rtc->max_user_freq = RTC_FREQ;
122 rtc_irq_set_freq(rtc, NULL, RTC_FREQ);
Marcelo Roberto Jimenezd2ccb522010-12-16 21:31:32 +0100123
Richard Purdiee842f1c2006-03-27 01:16:46 -0800124 return 0;
125
Richard Purdiee842f1c2006-03-27 01:16:46 -0800126 fail_ai:
Haojian Zhuang3888c092012-02-21 11:51:13 +0800127 free_irq(info->irq_1hz, dev);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800128 fail_ui:
Haojian Zhuang8e8bbcb2012-02-23 23:36:37 +0800129 clk_disable_unprepare(info->clk);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800130 return ret;
131}
132
133static void sa1100_rtc_release(struct device *dev)
134{
Haojian Zhuang3888c092012-02-21 11:51:13 +0800135 struct sa1100_rtc *info = dev_get_drvdata(dev);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800136
Haojian Zhuang3888c092012-02-21 11:51:13 +0800137 spin_lock_irq(&info->lock);
138 RTSR = 0;
139 spin_unlock_irq(&info->lock);
140
141 free_irq(info->irq_alarm, dev);
142 free_irq(info->irq_1hz, dev);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800143}
144
John Stultz16380c12011-02-02 17:02:41 -0800145static int sa1100_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
146{
Haojian Zhuang3888c092012-02-21 11:51:13 +0800147 struct sa1100_rtc *info = dev_get_drvdata(dev);
148
149 spin_lock_irq(&info->lock);
John Stultz16380c12011-02-02 17:02:41 -0800150 if (enabled)
Russell Kinga0164a52012-01-19 11:55:21 +0000151 RTSR |= RTSR_ALE;
John Stultz16380c12011-02-02 17:02:41 -0800152 else
Russell Kinga0164a52012-01-19 11:55:21 +0000153 RTSR &= ~RTSR_ALE;
Haojian Zhuang3888c092012-02-21 11:51:13 +0800154 spin_unlock_irq(&info->lock);
John Stultz16380c12011-02-02 17:02:41 -0800155 return 0;
156}
157
Richard Purdiee842f1c2006-03-27 01:16:46 -0800158static int sa1100_rtc_read_time(struct device *dev, struct rtc_time *tm)
159{
Russell Kinga0164a52012-01-19 11:55:21 +0000160 rtc_time_to_tm(RCNR, tm);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800161 return 0;
162}
163
164static int sa1100_rtc_set_time(struct device *dev, struct rtc_time *tm)
165{
166 unsigned long time;
167 int ret;
168
169 ret = rtc_tm_to_time(tm, &time);
170 if (ret == 0)
Russell Kinga0164a52012-01-19 11:55:21 +0000171 RCNR = time;
Richard Purdiee842f1c2006-03-27 01:16:46 -0800172 return ret;
173}
174
175static int sa1100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
176{
Russell Kinga0164a52012-01-19 11:55:21 +0000177 u32 rtsr;
David Brownell32b49da2007-02-20 13:58:13 -0800178
Russell Kinga0164a52012-01-19 11:55:21 +0000179 rtsr = RTSR;
David Brownell32b49da2007-02-20 13:58:13 -0800180 alrm->enabled = (rtsr & RTSR_ALE) ? 1 : 0;
181 alrm->pending = (rtsr & RTSR_AL) ? 1 : 0;
Richard Purdiee842f1c2006-03-27 01:16:46 -0800182 return 0;
183}
184
185static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
186{
Haojian Zhuang3888c092012-02-21 11:51:13 +0800187 struct sa1100_rtc *info = dev_get_drvdata(dev);
Haojian Zhuang1d8c38c2012-02-20 19:49:30 +0800188 unsigned long time;
Russell Kinga0164a52012-01-19 11:55:21 +0000189 int ret;
Richard Purdiee842f1c2006-03-27 01:16:46 -0800190
Haojian Zhuang3888c092012-02-21 11:51:13 +0800191 spin_lock_irq(&info->lock);
Haojian Zhuang1d8c38c2012-02-20 19:49:30 +0800192 ret = rtc_tm_to_time(&alrm->time, &time);
193 if (ret != 0)
194 goto out;
195 RTSR = RTSR & (RTSR_HZE|RTSR_ALE|RTSR_AL);
196 RTAR = time;
197 if (alrm->enabled)
198 RTSR |= RTSR_ALE;
199 else
200 RTSR &= ~RTSR_ALE;
201out:
Haojian Zhuang3888c092012-02-21 11:51:13 +0800202 spin_unlock_irq(&info->lock);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800203
Russell Kinga0164a52012-01-19 11:55:21 +0000204 return ret;
Richard Purdiee842f1c2006-03-27 01:16:46 -0800205}
206
207static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq)
208{
Russell Kinga0164a52012-01-19 11:55:21 +0000209 seq_printf(seq, "trim/divider\t\t: 0x%08x\n", (u32) RTTR);
210 seq_printf(seq, "RTSR\t\t\t: 0x%08x\n", (u32)RTSR);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800211
212 return 0;
213}
214
David Brownellff8371a2006-09-30 23:28:17 -0700215static const struct rtc_class_ops sa1100_rtc_ops = {
Richard Purdiee842f1c2006-03-27 01:16:46 -0800216 .open = sa1100_rtc_open,
Richard Purdiee842f1c2006-03-27 01:16:46 -0800217 .release = sa1100_rtc_release,
Richard Purdiee842f1c2006-03-27 01:16:46 -0800218 .read_time = sa1100_rtc_read_time,
219 .set_time = sa1100_rtc_set_time,
220 .read_alarm = sa1100_rtc_read_alarm,
221 .set_alarm = sa1100_rtc_set_alarm,
222 .proc = sa1100_rtc_proc,
John Stultz16380c12011-02-02 17:02:41 -0800223 .alarm_irq_enable = sa1100_rtc_alarm_irq_enable,
Richard Purdiee842f1c2006-03-27 01:16:46 -0800224};
225
226static int sa1100_rtc_probe(struct platform_device *pdev)
227{
Russell Kinga0164a52012-01-19 11:55:21 +0000228 struct rtc_device *rtc;
Haojian Zhuang3888c092012-02-21 11:51:13 +0800229 struct sa1100_rtc *info;
230 int irq_1hz, irq_alarm, ret = 0;
231
232 irq_1hz = platform_get_irq_byname(pdev, "rtc 1Hz");
233 irq_alarm = platform_get_irq_byname(pdev, "rtc alarm");
234 if (irq_1hz < 0 || irq_alarm < 0)
235 return -ENODEV;
236
Jingoo Han55d735e2013-04-29 16:20:54 -0700237 info = devm_kzalloc(&pdev->dev, sizeof(struct sa1100_rtc), GFP_KERNEL);
Haojian Zhuang3888c092012-02-21 11:51:13 +0800238 if (!info)
239 return -ENOMEM;
Jingoo Han55d735e2013-04-29 16:20:54 -0700240 info->clk = devm_clk_get(&pdev->dev, NULL);
Haojian Zhuang8e8bbcb2012-02-23 23:36:37 +0800241 if (IS_ERR(info->clk)) {
242 dev_err(&pdev->dev, "failed to find rtc clock source\n");
Jingoo Han55d735e2013-04-29 16:20:54 -0700243 return PTR_ERR(info->clk);
Haojian Zhuang8e8bbcb2012-02-23 23:36:37 +0800244 }
Haojian Zhuang3888c092012-02-21 11:51:13 +0800245 info->irq_1hz = irq_1hz;
246 info->irq_alarm = irq_alarm;
247 spin_lock_init(&info->lock);
248 platform_set_drvdata(pdev, info);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800249
Chao Xie0cc0c382013-02-21 16:45:17 -0800250 ret = clk_prepare_enable(info->clk);
251 if (ret)
Jingoo Han66600bb2013-07-03 15:06:35 -0700252 return ret;
Richard Purdiee842f1c2006-03-27 01:16:46 -0800253 /*
254 * According to the manual we should be able to let RTTR be zero
255 * and then a default diviser for a 32.768KHz clock is used.
256 * Apparently this doesn't work, at least for my SA1110 rev 5.
257 * If the clock divider is uninitialized then reset it to the
258 * default value to get the 1Hz clock.
259 */
Russell Kinga0164a52012-01-19 11:55:21 +0000260 if (RTTR == 0) {
261 RTTR = RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16);
262 dev_warn(&pdev->dev, "warning: "
263 "initializing default clock divider/trim value\n");
Richard Purdiee842f1c2006-03-27 01:16:46 -0800264 /* The current RTC value probably doesn't make sense either */
Russell Kinga0164a52012-01-19 11:55:21 +0000265 RCNR = 0;
Richard Purdiee842f1c2006-03-27 01:16:46 -0800266 }
267
Uli Luckase5a2c9c2008-06-18 09:54:03 +0100268 device_init_wakeup(&pdev->dev, 1);
269
Jingoo Han55d735e2013-04-29 16:20:54 -0700270 rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &sa1100_rtc_ops,
271 THIS_MODULE);
Russell Kinga0164a52012-01-19 11:55:21 +0000272
Haojian Zhuang3888c092012-02-21 11:51:13 +0800273 if (IS_ERR(rtc)) {
274 ret = PTR_ERR(rtc);
275 goto err_dev;
276 }
277 info->rtc = rtc;
Russell Kinga0164a52012-01-19 11:55:21 +0000278
Marcelo Roberto Jimenez7decaa52010-10-18 22:35:54 +0100279 /* Fix for a nasty initialization problem the in SA11xx RTSR register.
280 * See also the comments in sa1100_rtc_interrupt().
281 *
282 * Sometimes bit 1 of the RTSR (RTSR_HZ) will wake up 1, which means an
283 * interrupt pending, even though interrupts were never enabled.
284 * In this case, this bit it must be reset before enabling
285 * interruptions to avoid a nonexistent interrupt to occur.
286 *
287 * In principle, the same problem would apply to bit 0, although it has
288 * never been observed to happen.
289 *
290 * This issue is addressed both here and in sa1100_rtc_interrupt().
291 * If the issue is not addressed here, in the times when the processor
292 * wakes up with the bit set there will be one spurious interrupt.
293 *
294 * The issue is also dealt with in sa1100_rtc_interrupt() to be on the
295 * safe side, once the condition that lead to this strange
296 * initialization is unknown and could in principle happen during
297 * normal processing.
298 *
299 * Notice that clearing bit 1 and 0 is accomplished by writting ONES to
300 * the corresponding bits in RTSR. */
Russell Kinga0164a52012-01-19 11:55:21 +0000301 RTSR = RTSR_AL | RTSR_HZ;
Marcelo Roberto Jimenez7decaa52010-10-18 22:35:54 +0100302
Richard Purdiee842f1c2006-03-27 01:16:46 -0800303 return 0;
Haojian Zhuang3888c092012-02-21 11:51:13 +0800304err_dev:
Chao Xie0cc0c382013-02-21 16:45:17 -0800305 clk_disable_unprepare(info->clk);
Haojian Zhuang3888c092012-02-21 11:51:13 +0800306 return ret;
Richard Purdiee842f1c2006-03-27 01:16:46 -0800307}
308
309static int sa1100_rtc_remove(struct platform_device *pdev)
310{
Haojian Zhuang3888c092012-02-21 11:51:13 +0800311 struct sa1100_rtc *info = platform_get_drvdata(pdev);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800312
Jingoo Han66600bb2013-07-03 15:06:35 -0700313 if (info)
Chao Xie0cc0c382013-02-21 16:45:17 -0800314 clk_disable_unprepare(info->clk);
Russell Kinga0164a52012-01-19 11:55:21 +0000315
Richard Purdiee842f1c2006-03-27 01:16:46 -0800316 return 0;
317}
318
Jingoo Hanaaa92fa2013-04-29 16:19:59 -0700319#ifdef CONFIG_PM_SLEEP
Haojian Zhuang5d027cd2009-07-21 14:31:09 +0800320static int sa1100_rtc_suspend(struct device *dev)
Russell King6bc54e62007-11-12 22:49:58 +0000321{
Haojian Zhuang3888c092012-02-21 11:51:13 +0800322 struct sa1100_rtc *info = dev_get_drvdata(dev);
Haojian Zhuang5d027cd2009-07-21 14:31:09 +0800323 if (device_may_wakeup(dev))
Haojian Zhuang3888c092012-02-21 11:51:13 +0800324 enable_irq_wake(info->irq_alarm);
Russell King6bc54e62007-11-12 22:49:58 +0000325 return 0;
326}
327
Haojian Zhuang5d027cd2009-07-21 14:31:09 +0800328static int sa1100_rtc_resume(struct device *dev)
Russell King6bc54e62007-11-12 22:49:58 +0000329{
Haojian Zhuang3888c092012-02-21 11:51:13 +0800330 struct sa1100_rtc *info = dev_get_drvdata(dev);
Haojian Zhuang5d027cd2009-07-21 14:31:09 +0800331 if (device_may_wakeup(dev))
Haojian Zhuang3888c092012-02-21 11:51:13 +0800332 disable_irq_wake(info->irq_alarm);
Russell King6bc54e62007-11-12 22:49:58 +0000333 return 0;
334}
Russell King6bc54e62007-11-12 22:49:58 +0000335#endif
336
Jingoo Hanaaa92fa2013-04-29 16:19:59 -0700337static SIMPLE_DEV_PM_OPS(sa1100_rtc_pm_ops, sa1100_rtc_suspend,
338 sa1100_rtc_resume);
339
Sachin Kamatc8a60462013-02-21 16:44:28 -0800340#ifdef CONFIG_OF
Haojian Zhuang8bec2e92012-03-05 19:26:42 +0800341static struct of_device_id sa1100_rtc_dt_ids[] = {
342 { .compatible = "mrvl,sa1100-rtc", },
343 { .compatible = "mrvl,mmp-rtc", },
344 {}
345};
346MODULE_DEVICE_TABLE(of, sa1100_rtc_dt_ids);
Sachin Kamatc8a60462013-02-21 16:44:28 -0800347#endif
Haojian Zhuang8bec2e92012-03-05 19:26:42 +0800348
Richard Purdiee842f1c2006-03-27 01:16:46 -0800349static struct platform_driver sa1100_rtc_driver = {
350 .probe = sa1100_rtc_probe,
351 .remove = sa1100_rtc_remove,
Richard Purdiee842f1c2006-03-27 01:16:46 -0800352 .driver = {
Haojian Zhuang5d027cd2009-07-21 14:31:09 +0800353 .name = "sa1100-rtc",
Haojian Zhuang5d027cd2009-07-21 14:31:09 +0800354 .pm = &sa1100_rtc_pm_ops,
Sachin Kamatc8a60462013-02-21 16:44:28 -0800355 .of_match_table = of_match_ptr(sa1100_rtc_dt_ids),
Richard Purdiee842f1c2006-03-27 01:16:46 -0800356 },
357};
358
Axel Lin0c4eae62012-01-10 15:10:48 -0800359module_platform_driver(sa1100_rtc_driver);
Richard Purdiee842f1c2006-03-27 01:16:46 -0800360
361MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
362MODULE_DESCRIPTION("SA11x0/PXA2xx Realtime Clock Driver (RTC)");
363MODULE_LICENSE("GPL");
Kay Sieversad28a072008-04-10 21:29:25 -0700364MODULE_ALIAS("platform:sa1100-rtc");