2 * Freescale STMP37XX/STMP378X Real Time Clock driver
4 * Copyright (c) 2007 Sigmatel, Inc.
5 * Peter Hartley, <peter.hartley@sigmatel.com>
7 * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
8 * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
9 * Copyright 2011 Wolfram Sang, Pengutronix e.K.
13 * The code contained herein is licensed under the GNU General Public
14 * License. You may obtain a copy of the GNU General Public License
15 * Version 2 or later at the following locations:
17 * http://www.opensource.org/licenses/gpl-license.html
18 * http://www.gnu.org/copyleft/gpl.html
20 #include <linux/kernel.h>
21 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/platform_device.h>
25 #include <linux/interrupt.h>
26 #include <linux/rtc.h>
27 #include <linux/slab.h>
28 #include <linux/of_device.h>
31 #include <mach/common.h>
33 #define STMP3XXX_RTC_CTRL 0x0
34 #define STMP3XXX_RTC_CTRL_SET 0x4
35 #define STMP3XXX_RTC_CTRL_CLR 0x8
36 #define STMP3XXX_RTC_CTRL_ALARM_IRQ_EN 0x00000001
37 #define STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN 0x00000002
38 #define STMP3XXX_RTC_CTRL_ALARM_IRQ 0x00000004
40 #define STMP3XXX_RTC_STAT 0x10
41 #define STMP3XXX_RTC_STAT_STALE_SHIFT 16
42 #define STMP3XXX_RTC_STAT_RTC_PRESENT 0x80000000
44 #define STMP3XXX_RTC_SECONDS 0x30
46 #define STMP3XXX_RTC_ALARM 0x40
48 #define STMP3XXX_RTC_PERSISTENT0 0x60
49 #define STMP3XXX_RTC_PERSISTENT0_SET 0x64
50 #define STMP3XXX_RTC_PERSISTENT0_CLR 0x68
51 #define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN 0x00000002
52 #define STMP3XXX_RTC_PERSISTENT0_ALARM_EN 0x00000004
53 #define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE 0x00000080
55 struct stmp3xxx_rtc_data {
56 struct rtc_device *rtc;
61 static void stmp3xxx_wait_time(struct stmp3xxx_rtc_data *rtc_data)
64 * The datasheet doesn't say which way round the
65 * NEW_REGS/STALE_REGS bitfields go. In fact it's 0x1=P0,
66 * 0x2=P1, .., 0x20=P5, 0x40=ALARM, 0x80=SECONDS
68 while (readl(rtc_data->io + STMP3XXX_RTC_STAT) &
69 (0x80 << STMP3XXX_RTC_STAT_STALE_SHIFT))
74 static int stmp3xxx_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
76 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
78 stmp3xxx_wait_time(rtc_data);
79 rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_SECONDS), rtc_tm);
83 static int stmp3xxx_rtc_set_mmss(struct device *dev, unsigned long t)
85 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
87 writel(t, rtc_data->io + STMP3XXX_RTC_SECONDS);
88 stmp3xxx_wait_time(rtc_data);
92 /* interrupt(s) handler */
93 static irqreturn_t stmp3xxx_rtc_interrupt(int irq, void *dev_id)
95 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev_id);
96 u32 status = readl(rtc_data->io + STMP3XXX_RTC_CTRL);
98 if (status & STMP3XXX_RTC_CTRL_ALARM_IRQ) {
99 writel(STMP3XXX_RTC_CTRL_ALARM_IRQ,
100 rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
101 rtc_update_irq(rtc_data->rtc, 1, RTC_AF | RTC_IRQF);
108 static int stmp3xxx_alarm_irq_enable(struct device *dev, unsigned int enabled)
110 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
113 writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
114 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
115 rtc_data->io + STMP3XXX_RTC_PERSISTENT0_SET);
116 writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
117 rtc_data->io + STMP3XXX_RTC_CTRL_SET);
119 writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
120 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
121 rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR);
122 writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
123 rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
128 static int stmp3xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
130 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
132 rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_ALARM), &alm->time);
136 static int stmp3xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
139 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
141 rtc_tm_to_time(&alm->time, &t);
142 writel(t, rtc_data->io + STMP3XXX_RTC_ALARM);
144 stmp3xxx_alarm_irq_enable(dev, alm->enabled);
149 static struct rtc_class_ops stmp3xxx_rtc_ops = {
151 stmp3xxx_alarm_irq_enable,
152 .read_time = stmp3xxx_rtc_gettime,
153 .set_mmss = stmp3xxx_rtc_set_mmss,
154 .read_alarm = stmp3xxx_rtc_read_alarm,
155 .set_alarm = stmp3xxx_rtc_set_alarm,
158 static int stmp3xxx_rtc_remove(struct platform_device *pdev)
160 struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(pdev);
165 writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
166 rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
167 free_irq(rtc_data->irq_alarm, &pdev->dev);
168 rtc_device_unregister(rtc_data->rtc);
169 platform_set_drvdata(pdev, NULL);
170 iounmap(rtc_data->io);
176 static int stmp3xxx_rtc_probe(struct platform_device *pdev)
178 struct stmp3xxx_rtc_data *rtc_data;
182 rtc_data = kzalloc(sizeof *rtc_data, GFP_KERNEL);
186 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
188 dev_err(&pdev->dev, "failed to get resource\n");
193 rtc_data->io = ioremap(r->start, resource_size(r));
195 dev_err(&pdev->dev, "ioremap failed\n");
200 rtc_data->irq_alarm = platform_get_irq(pdev, 0);
202 if (!(readl(STMP3XXX_RTC_STAT + rtc_data->io) &
203 STMP3XXX_RTC_STAT_RTC_PRESENT)) {
204 dev_err(&pdev->dev, "no device onboard\n");
209 platform_set_drvdata(pdev, rtc_data);
211 mxs_reset_block(rtc_data->io);
212 writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
213 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
214 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE,
215 rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR);
217 writel(STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN |
218 STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
219 rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
221 rtc_data->rtc = rtc_device_register(pdev->name, &pdev->dev,
222 &stmp3xxx_rtc_ops, THIS_MODULE);
223 if (IS_ERR(rtc_data->rtc)) {
224 err = PTR_ERR(rtc_data->rtc);
228 err = request_irq(rtc_data->irq_alarm, stmp3xxx_rtc_interrupt, 0,
229 "RTC alarm", &pdev->dev);
231 dev_err(&pdev->dev, "Cannot claim IRQ%d\n",
232 rtc_data->irq_alarm);
239 rtc_device_unregister(rtc_data->rtc);
241 platform_set_drvdata(pdev, NULL);
242 iounmap(rtc_data->io);
249 static int stmp3xxx_rtc_suspend(struct platform_device *dev, pm_message_t state)
254 static int stmp3xxx_rtc_resume(struct platform_device *dev)
256 struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(dev);
258 mxs_reset_block(rtc_data->io);
259 writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
260 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
261 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE,
262 rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR);
266 #define stmp3xxx_rtc_suspend NULL
267 #define stmp3xxx_rtc_resume NULL
270 static const struct of_device_id rtc_dt_ids[] = {
271 { .compatible = "fsl,stmp3xxx-rtc", },
274 MODULE_DEVICE_TABLE(of, rtc_dt_ids);
276 static struct platform_driver stmp3xxx_rtcdrv = {
277 .probe = stmp3xxx_rtc_probe,
278 .remove = stmp3xxx_rtc_remove,
279 .suspend = stmp3xxx_rtc_suspend,
280 .resume = stmp3xxx_rtc_resume,
282 .name = "stmp3xxx-rtc",
283 .owner = THIS_MODULE,
284 .of_match_table = of_match_ptr(rtc_dt_ids),
288 module_platform_driver(stmp3xxx_rtcdrv);
290 MODULE_DESCRIPTION("STMP3xxx RTC Driver");
291 MODULE_AUTHOR("dmitry pervushin <dpervushin@embeddedalley.com> and "
292 "Wolfram Sang <w.sang@pengutronix.de>");
293 MODULE_LICENSE("GPL");