tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Freescale STMP37XX/STMP378X Real Time Clock driver
3 *
4 * Copyright (c) 2007 Sigmatel, Inc.
5 * Peter Hartley, <peter.hartley@sigmatel.com>
6 *
7 * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
8 * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
9 */
10
11/*
12 * The code contained herein is licensed under the GNU General Public
13 * License. You may obtain a copy of the GNU General Public License
14 * Version 2 or later at the following locations:
15 *
16 * http://www.opensource.org/licenses/gpl-license.html
17 * http://www.gnu.org/copyleft/gpl.html
18 */
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/init.h>
22#include <linux/platform_device.h>
23#include <linux/interrupt.h>
24#include <linux/rtc.h>
25#include <linux/slab.h>
26
27#include <mach/platform.h>
28#include <mach/stmp3xxx.h>
29#include <mach/regs-rtc.h>
30
31struct stmp3xxx_rtc_data {
32 struct rtc_device *rtc;
33 unsigned irq_count;
34 void __iomem *io;
35 int irq_alarm, irq_1msec;
36};
37
38static void stmp3xxx_wait_time(struct stmp3xxx_rtc_data *rtc_data)
39{
40 /*
41 * The datasheet doesn't say which way round the
42 * NEW_REGS/STALE_REGS bitfields go. In fact it's 0x1=P0,
43 * 0x2=P1, .., 0x20=P5, 0x40=ALARM, 0x80=SECONDS
44 */
45 while (__raw_readl(rtc_data->io + HW_RTC_STAT) &
46 BF(0x80, RTC_STAT_STALE_REGS))
47 cpu_relax();
48}
49
50/* Time read/write */
51static int stmp3xxx_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
52{
53 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
54
55 stmp3xxx_wait_time(rtc_data);
56 rtc_time_to_tm(__raw_readl(rtc_data->io + HW_RTC_SECONDS), rtc_tm);
57 return 0;
58}
59
60static int stmp3xxx_rtc_set_mmss(struct device *dev, unsigned long t)
61{
62 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
63
64 __raw_writel(t, rtc_data->io + HW_RTC_SECONDS);
65 stmp3xxx_wait_time(rtc_data);
66 return 0;
67}
68
69/* interrupt(s) handler */
70static irqreturn_t stmp3xxx_rtc_interrupt(int irq, void *dev_id)
71{
72 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev_id);
73 u32 status;
74 u32 events = 0;
75
76 status = __raw_readl(rtc_data->io + HW_RTC_CTRL) &
77 (BM_RTC_CTRL_ALARM_IRQ | BM_RTC_CTRL_ONEMSEC_IRQ);
78
79 if (status & BM_RTC_CTRL_ALARM_IRQ) {
80 stmp3xxx_clearl(BM_RTC_CTRL_ALARM_IRQ,
81 rtc_data->io + HW_RTC_CTRL);
82 events |= RTC_AF | RTC_IRQF;
83 }
84
85 if (status & BM_RTC_CTRL_ONEMSEC_IRQ) {
86 stmp3xxx_clearl(BM_RTC_CTRL_ONEMSEC_IRQ,
87 rtc_data->io + HW_RTC_CTRL);
88 if (++rtc_data->irq_count % 1000 == 0) {
89 events |= RTC_UF | RTC_IRQF;
90 rtc_data->irq_count = 0;
91 }
92 }
93
94 if (events)
95 rtc_update_irq(rtc_data->rtc, 1, events);
96
97 return IRQ_HANDLED;
98}
99
100static int stmp3xxx_alarm_irq_enable(struct device *dev, unsigned int enabled)
101{
102 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
103 void __iomem *p = rtc_data->io + HW_RTC_PERSISTENT0,
104 *ctl = rtc_data->io + HW_RTC_CTRL;
105
106 if (enabled) {
107 stmp3xxx_setl(BM_RTC_PERSISTENT0_ALARM_EN |
108 BM_RTC_PERSISTENT0_ALARM_WAKE_EN, p);
109 stmp3xxx_setl(BM_RTC_CTRL_ALARM_IRQ_EN, ctl);
110 } else {
111 stmp3xxx_clearl(BM_RTC_PERSISTENT0_ALARM_EN |
112 BM_RTC_PERSISTENT0_ALARM_WAKE_EN, p);
113 stmp3xxx_clearl(BM_RTC_CTRL_ALARM_IRQ_EN, ctl);
114 }
115 return 0;
116}
117
118static int stmp3xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
119{
120 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
121
122 rtc_time_to_tm(__raw_readl(rtc_data->io + HW_RTC_ALARM), &alm->time);
123 return 0;
124}
125
126static int stmp3xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
127{
128 unsigned long t;
129 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
130
131 rtc_tm_to_time(&alm->time, &t);
132 __raw_writel(t, rtc_data->io + HW_RTC_ALARM);
133 return 0;
134}
135
136static struct rtc_class_ops stmp3xxx_rtc_ops = {
137 .alarm_irq_enable =
138 stmp3xxx_alarm_irq_enable,
139 .read_time = stmp3xxx_rtc_gettime,
140 .set_mmss = stmp3xxx_rtc_set_mmss,
141 .read_alarm = stmp3xxx_rtc_read_alarm,
142 .set_alarm = stmp3xxx_rtc_set_alarm,
143};
144
145static int stmp3xxx_rtc_remove(struct platform_device *pdev)
146{
147 struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(pdev);
148
149 if (!rtc_data)
150 return 0;
151
152 stmp3xxx_clearl(BM_RTC_CTRL_ONEMSEC_IRQ_EN | BM_RTC_CTRL_ALARM_IRQ_EN,
153 rtc_data->io + HW_RTC_CTRL);
154 free_irq(rtc_data->irq_alarm, &pdev->dev);
155 free_irq(rtc_data->irq_1msec, &pdev->dev);
156 rtc_device_unregister(rtc_data->rtc);
157 iounmap(rtc_data->io);
158 kfree(rtc_data);
159
160 return 0;
161}
162
163static int stmp3xxx_rtc_probe(struct platform_device *pdev)
164{
165 struct stmp3xxx_rtc_data *rtc_data;
166 struct resource *r;
167 int err;
168
169 rtc_data = kzalloc(sizeof *rtc_data, GFP_KERNEL);
170 if (!rtc_data)
171 return -ENOMEM;
172
173 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
174 if (!r) {
175 dev_err(&pdev->dev, "failed to get resource\n");
176 err = -ENXIO;
177 goto out_free;
178 }
179
180 rtc_data->io = ioremap(r->start, resource_size(r));
181 if (!rtc_data->io) {
182 dev_err(&pdev->dev, "ioremap failed\n");
183 err = -EIO;
184 goto out_free;
185 }
186
187 rtc_data->irq_alarm = platform_get_irq(pdev, 0);
188 rtc_data->irq_1msec = platform_get_irq(pdev, 1);
189
190 if (!(__raw_readl(HW_RTC_STAT + rtc_data->io) &
191 BM_RTC_STAT_RTC_PRESENT)) {
192 dev_err(&pdev->dev, "no device onboard\n");
193 err = -ENODEV;
194 goto out_remap;
195 }
196
197 stmp3xxx_reset_block(rtc_data->io, true);
198 stmp3xxx_clearl(BM_RTC_PERSISTENT0_ALARM_EN |
199 BM_RTC_PERSISTENT0_ALARM_WAKE_EN |
200 BM_RTC_PERSISTENT0_ALARM_WAKE,
201 rtc_data->io + HW_RTC_PERSISTENT0);
202 rtc_data->rtc = rtc_device_register(pdev->name, &pdev->dev,
203 &stmp3xxx_rtc_ops, THIS_MODULE);
204 if (IS_ERR(rtc_data->rtc)) {
205 err = PTR_ERR(rtc_data->rtc);
206 goto out_remap;
207 }
208
209 rtc_data->irq_count = 0;
210 err = request_irq(rtc_data->irq_alarm, stmp3xxx_rtc_interrupt,
211 IRQF_DISABLED, "RTC alarm", &pdev->dev);
212 if (err) {
213 dev_err(&pdev->dev, "Cannot claim IRQ%d\n",
214 rtc_data->irq_alarm);
215 goto out_irq_alarm;
216 }
217 err = request_irq(rtc_data->irq_1msec, stmp3xxx_rtc_interrupt,
218 IRQF_DISABLED, "RTC tick", &pdev->dev);
219 if (err) {
220 dev_err(&pdev->dev, "Cannot claim IRQ%d\n",
221 rtc_data->irq_1msec);
222 goto out_irq1;
223 }
224
225 platform_set_drvdata(pdev, rtc_data);
226
227 return 0;
228
229out_irq1:
230 free_irq(rtc_data->irq_alarm, &pdev->dev);
231out_irq_alarm:
232 stmp3xxx_clearl(BM_RTC_CTRL_ONEMSEC_IRQ_EN | BM_RTC_CTRL_ALARM_IRQ_EN,
233 rtc_data->io + HW_RTC_CTRL);
234 rtc_device_unregister(rtc_data->rtc);
235out_remap:
236 iounmap(rtc_data->io);
237out_free:
238 kfree(rtc_data);
239 return err;
240}
241
242#ifdef CONFIG_PM
243static int stmp3xxx_rtc_suspend(struct platform_device *dev, pm_message_t state)
244{
245 return 0;
246}
247
248static int stmp3xxx_rtc_resume(struct platform_device *dev)
249{
250 struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(dev);
251
252 stmp3xxx_reset_block(rtc_data->io, true);
253 stmp3xxx_clearl(BM_RTC_PERSISTENT0_ALARM_EN |
254 BM_RTC_PERSISTENT0_ALARM_WAKE_EN |
255 BM_RTC_PERSISTENT0_ALARM_WAKE,
256 rtc_data->io + HW_RTC_PERSISTENT0);
257 return 0;
258}
259#else
260#define stmp3xxx_rtc_suspend NULL
261#define stmp3xxx_rtc_resume NULL
262#endif
263
264static struct platform_driver stmp3xxx_rtcdrv = {
265 .probe = stmp3xxx_rtc_probe,
266 .remove = stmp3xxx_rtc_remove,
267 .suspend = stmp3xxx_rtc_suspend,
268 .resume = stmp3xxx_rtc_resume,
269 .driver = {
270 .name = "stmp3xxx-rtc",
271 .owner = THIS_MODULE,
272 },
273};
274
275static int __init stmp3xxx_rtc_init(void)
276{
277 return platform_driver_register(&stmp3xxx_rtcdrv);
278}
279
280static void __exit stmp3xxx_rtc_exit(void)
281{
282 platform_driver_unregister(&stmp3xxx_rtcdrv);
283}
284
285module_init(stmp3xxx_rtc_init);
286module_exit(stmp3xxx_rtc_exit);
287
288MODULE_DESCRIPTION("STMP3xxx RTC Driver");
289MODULE_AUTHOR("dmitry pervushin <dpervushin@embeddedalley.com>");
290MODULE_LICENSE("GPL");