Root/drivers/rtc/rtc-tx4939.c

1/*
2 * TX4939 internal RTC driver
3 * Based on RBTX49xx patch from CELF patch archive.
4 *
5 * This file is subject to the terms and conditions of the GNU General Public
6 * License. See the file "COPYING" in the main directory of this archive
7 * for more details.
8 *
9 * (C) Copyright TOSHIBA CORPORATION 2005-2007
10 */
11#include <linux/rtc.h>
12#include <linux/platform_device.h>
13#include <linux/interrupt.h>
14#include <linux/module.h>
15#include <linux/io.h>
16#include <linux/gfp.h>
17#include <asm/txx9/tx4939.h>
18
19struct tx4939rtc_plat_data {
20    struct rtc_device *rtc;
21    struct tx4939_rtc_reg __iomem *rtcreg;
22    spinlock_t lock;
23};
24
25static struct tx4939rtc_plat_data *get_tx4939rtc_plat_data(struct device *dev)
26{
27    return platform_get_drvdata(to_platform_device(dev));
28}
29
30static int tx4939_rtc_cmd(struct tx4939_rtc_reg __iomem *rtcreg, int cmd)
31{
32    int i = 0;
33
34    __raw_writel(cmd, &rtcreg->ctl);
35    /* This might take 30us (next 32.768KHz clock) */
36    while (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_BUSY) {
37        /* timeout on approx. 100us (@ GBUS200MHz) */
38        if (i++ > 200 * 100)
39            return -EBUSY;
40        cpu_relax();
41    }
42    return 0;
43}
44
45static int tx4939_rtc_set_mmss(struct device *dev, unsigned long secs)
46{
47    struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
48    struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
49    int i, ret;
50    unsigned char buf[6];
51
52    buf[0] = 0;
53    buf[1] = 0;
54    buf[2] = secs;
55    buf[3] = secs >> 8;
56    buf[4] = secs >> 16;
57    buf[5] = secs >> 24;
58    spin_lock_irq(&pdata->lock);
59    __raw_writel(0, &rtcreg->adr);
60    for (i = 0; i < 6; i++)
61        __raw_writel(buf[i], &rtcreg->dat);
62    ret = tx4939_rtc_cmd(rtcreg,
63                 TX4939_RTCCTL_COMMAND_SETTIME |
64                 (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
65    spin_unlock_irq(&pdata->lock);
66    return ret;
67}
68
69static int tx4939_rtc_read_time(struct device *dev, struct rtc_time *tm)
70{
71    struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
72    struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
73    int i, ret;
74    unsigned long sec;
75    unsigned char buf[6];
76
77    spin_lock_irq(&pdata->lock);
78    ret = tx4939_rtc_cmd(rtcreg,
79                 TX4939_RTCCTL_COMMAND_GETTIME |
80                 (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
81    if (ret) {
82        spin_unlock_irq(&pdata->lock);
83        return ret;
84    }
85    __raw_writel(2, &rtcreg->adr);
86    for (i = 2; i < 6; i++)
87        buf[i] = __raw_readl(&rtcreg->dat);
88    spin_unlock_irq(&pdata->lock);
89    sec = (buf[5] << 24) | (buf[4] << 16) | (buf[3] << 8) | buf[2];
90    rtc_time_to_tm(sec, tm);
91    return rtc_valid_tm(tm);
92}
93
94static int tx4939_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
95{
96    struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
97    struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
98    int i, ret;
99    unsigned long sec;
100    unsigned char buf[6];
101
102    if (alrm->time.tm_sec < 0 ||
103        alrm->time.tm_min < 0 ||
104        alrm->time.tm_hour < 0 ||
105        alrm->time.tm_mday < 0 ||
106        alrm->time.tm_mon < 0 ||
107        alrm->time.tm_year < 0)
108        return -EINVAL;
109    rtc_tm_to_time(&alrm->time, &sec);
110    buf[0] = 0;
111    buf[1] = 0;
112    buf[2] = sec;
113    buf[3] = sec >> 8;
114    buf[4] = sec >> 16;
115    buf[5] = sec >> 24;
116    spin_lock_irq(&pdata->lock);
117    __raw_writel(0, &rtcreg->adr);
118    for (i = 0; i < 6; i++)
119        __raw_writel(buf[i], &rtcreg->dat);
120    ret = tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_SETALARM |
121                 (alrm->enabled ? TX4939_RTCCTL_ALME : 0));
122    spin_unlock_irq(&pdata->lock);
123    return ret;
124}
125
126static int tx4939_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
127{
128    struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
129    struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
130    int i, ret;
131    unsigned long sec;
132    unsigned char buf[6];
133    u32 ctl;
134
135    spin_lock_irq(&pdata->lock);
136    ret = tx4939_rtc_cmd(rtcreg,
137                 TX4939_RTCCTL_COMMAND_GETALARM |
138                 (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
139    if (ret) {
140        spin_unlock_irq(&pdata->lock);
141        return ret;
142    }
143    __raw_writel(2, &rtcreg->adr);
144    for (i = 2; i < 6; i++)
145        buf[i] = __raw_readl(&rtcreg->dat);
146    ctl = __raw_readl(&rtcreg->ctl);
147    alrm->enabled = (ctl & TX4939_RTCCTL_ALME) ? 1 : 0;
148    alrm->pending = (ctl & TX4939_RTCCTL_ALMD) ? 1 : 0;
149    spin_unlock_irq(&pdata->lock);
150    sec = (buf[5] << 24) | (buf[4] << 16) | (buf[3] << 8) | buf[2];
151    rtc_time_to_tm(sec, &alrm->time);
152    return rtc_valid_tm(&alrm->time);
153}
154
155static int tx4939_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
156{
157    struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
158
159    spin_lock_irq(&pdata->lock);
160    tx4939_rtc_cmd(pdata->rtcreg,
161               TX4939_RTCCTL_COMMAND_NOP |
162               (enabled ? TX4939_RTCCTL_ALME : 0));
163    spin_unlock_irq(&pdata->lock);
164    return 0;
165}
166
167static irqreturn_t tx4939_rtc_interrupt(int irq, void *dev_id)
168{
169    struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev_id);
170    struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
171    unsigned long events = RTC_IRQF;
172
173    spin_lock(&pdata->lock);
174    if (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALMD) {
175        events |= RTC_AF;
176        tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_NOP);
177    }
178    spin_unlock(&pdata->lock);
179    if (likely(pdata->rtc))
180        rtc_update_irq(pdata->rtc, 1, events);
181    return IRQ_HANDLED;
182}
183
184static const struct rtc_class_ops tx4939_rtc_ops = {
185    .read_time = tx4939_rtc_read_time,
186    .read_alarm = tx4939_rtc_read_alarm,
187    .set_alarm = tx4939_rtc_set_alarm,
188    .set_mmss = tx4939_rtc_set_mmss,
189    .alarm_irq_enable = tx4939_rtc_alarm_irq_enable,
190};
191
192static ssize_t tx4939_rtc_nvram_read(struct file *filp, struct kobject *kobj,
193                     struct bin_attribute *bin_attr,
194                     char *buf, loff_t pos, size_t size)
195{
196    struct device *dev = container_of(kobj, struct device, kobj);
197    struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
198    struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
199    ssize_t count;
200
201    spin_lock_irq(&pdata->lock);
202    for (count = 0; size > 0 && pos < TX4939_RTC_REG_RAMSIZE;
203         count++, size--) {
204        __raw_writel(pos++, &rtcreg->adr);
205        *buf++ = __raw_readl(&rtcreg->dat);
206    }
207    spin_unlock_irq(&pdata->lock);
208    return count;
209}
210
211static ssize_t tx4939_rtc_nvram_write(struct file *filp, struct kobject *kobj,
212                      struct bin_attribute *bin_attr,
213                      char *buf, loff_t pos, size_t size)
214{
215    struct device *dev = container_of(kobj, struct device, kobj);
216    struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
217    struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
218    ssize_t count;
219
220    spin_lock_irq(&pdata->lock);
221    for (count = 0; size > 0 && pos < TX4939_RTC_REG_RAMSIZE;
222         count++, size--) {
223        __raw_writel(pos++, &rtcreg->adr);
224        __raw_writel(*buf++, &rtcreg->dat);
225    }
226    spin_unlock_irq(&pdata->lock);
227    return count;
228}
229
230static struct bin_attribute tx4939_rtc_nvram_attr = {
231    .attr = {
232        .name = "nvram",
233        .mode = S_IRUGO | S_IWUSR,
234    },
235    .size = TX4939_RTC_REG_RAMSIZE,
236    .read = tx4939_rtc_nvram_read,
237    .write = tx4939_rtc_nvram_write,
238};
239
240static int __init tx4939_rtc_probe(struct platform_device *pdev)
241{
242    struct rtc_device *rtc;
243    struct tx4939rtc_plat_data *pdata;
244    struct resource *res;
245    int irq, ret;
246
247    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
248    if (!res)
249        return -ENODEV;
250    irq = platform_get_irq(pdev, 0);
251    if (irq < 0)
252        return -ENODEV;
253    pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
254    if (!pdata)
255        return -ENOMEM;
256    platform_set_drvdata(pdev, pdata);
257
258    if (!devm_request_mem_region(&pdev->dev, res->start,
259                     resource_size(res), pdev->name))
260        return -EBUSY;
261    pdata->rtcreg = devm_ioremap(&pdev->dev, res->start,
262                     resource_size(res));
263    if (!pdata->rtcreg)
264        return -EBUSY;
265
266    spin_lock_init(&pdata->lock);
267    tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP);
268    if (devm_request_irq(&pdev->dev, irq, tx4939_rtc_interrupt,
269                 0, pdev->name, &pdev->dev) < 0)
270        return -EBUSY;
271    rtc = rtc_device_register(pdev->name, &pdev->dev,
272                  &tx4939_rtc_ops, THIS_MODULE);
273    if (IS_ERR(rtc))
274        return PTR_ERR(rtc);
275    pdata->rtc = rtc;
276    ret = sysfs_create_bin_file(&pdev->dev.kobj, &tx4939_rtc_nvram_attr);
277    if (ret)
278        rtc_device_unregister(rtc);
279    return ret;
280}
281
282static int __exit tx4939_rtc_remove(struct platform_device *pdev)
283{
284    struct tx4939rtc_plat_data *pdata = platform_get_drvdata(pdev);
285
286    sysfs_remove_bin_file(&pdev->dev.kobj, &tx4939_rtc_nvram_attr);
287    rtc_device_unregister(pdata->rtc);
288    spin_lock_irq(&pdata->lock);
289    tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP);
290    spin_unlock_irq(&pdata->lock);
291    return 0;
292}
293
294static struct platform_driver tx4939_rtc_driver = {
295    .remove = __exit_p(tx4939_rtc_remove),
296    .driver = {
297        .name = "tx4939rtc",
298        .owner = THIS_MODULE,
299    },
300};
301
302static int __init tx4939rtc_init(void)
303{
304    return platform_driver_probe(&tx4939_rtc_driver, tx4939_rtc_probe);
305}
306
307static void __exit tx4939rtc_exit(void)
308{
309    platform_driver_unregister(&tx4939_rtc_driver);
310}
311
312module_init(tx4939rtc_init);
313module_exit(tx4939rtc_exit);
314
315MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
316MODULE_DESCRIPTION("TX4939 internal RTC driver");
317MODULE_LICENSE("GPL");
318MODULE_ALIAS("platform:tx4939rtc");
319

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