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