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v3.1
 
  1/*
  2 * Copyright (C) ST-Ericsson SA 2010
  3 *
  4 * License terms: GNU General Public License (GPL) version 2
  5 * Author: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
  6 *
  7 * RTC clock driver for the RTC part of the AB8500 Power management chip.
  8 * Based on RTC clock driver for the AB3100 Analog Baseband Chip by
  9 * Linus Walleij <linus.walleij@stericsson.com>
 10 */
 11
 12#include <linux/module.h>
 13#include <linux/kernel.h>
 14#include <linux/init.h>
 15#include <linux/platform_device.h>
 16#include <linux/rtc.h>
 17#include <linux/mfd/abx500.h>
 18#include <linux/mfd/ab8500.h>
 19#include <linux/delay.h>
 
 
 20
 21#define AB8500_RTC_SOFF_STAT_REG	0x00
 22#define AB8500_RTC_CC_CONF_REG		0x01
 23#define AB8500_RTC_READ_REQ_REG		0x02
 24#define AB8500_RTC_WATCH_TSECMID_REG	0x03
 25#define AB8500_RTC_WATCH_TSECHI_REG	0x04
 26#define AB8500_RTC_WATCH_TMIN_LOW_REG	0x05
 27#define AB8500_RTC_WATCH_TMIN_MID_REG	0x06
 28#define AB8500_RTC_WATCH_TMIN_HI_REG	0x07
 29#define AB8500_RTC_ALRM_MIN_LOW_REG	0x08
 30#define AB8500_RTC_ALRM_MIN_MID_REG	0x09
 31#define AB8500_RTC_ALRM_MIN_HI_REG	0x0A
 32#define AB8500_RTC_STAT_REG		0x0B
 33#define AB8500_RTC_BKUP_CHG_REG		0x0C
 34#define AB8500_RTC_FORCE_BKUP_REG	0x0D
 35#define AB8500_RTC_CALIB_REG		0x0E
 36#define AB8500_RTC_SWITCH_STAT_REG	0x0F
 37
 38/* RtcReadRequest bits */
 39#define RTC_READ_REQUEST		0x01
 40#define RTC_WRITE_REQUEST		0x02
 41
 42/* RtcCtrl bits */
 43#define RTC_ALARM_ENA			0x04
 44#define RTC_STATUS_DATA			0x01
 45
 46#define COUNTS_PER_SEC			(0xF000 / 60)
 47#define AB8500_RTC_EPOCH		2000
 48
 49static const u8 ab8500_rtc_time_regs[] = {
 50	AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
 51	AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,
 52	AB8500_RTC_WATCH_TSECMID_REG
 53};
 54
 55static const u8 ab8500_rtc_alarm_regs[] = {
 56	AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,
 57	AB8500_RTC_ALRM_MIN_LOW_REG
 58};
 59
 60/* Calculate the seconds from 1970 to 01-01-2000 00:00:00 */
 61static unsigned long get_elapsed_seconds(int year)
 62{
 63	unsigned long secs;
 64	struct rtc_time tm = {
 65		.tm_year = year - 1900,
 66		.tm_mday = 1,
 67	};
 68
 69	/*
 70	 * This function calculates secs from 1970 and not from
 71	 * 1900, even if we supply the offset from year 1900.
 72	 */
 73	rtc_tm_to_time(&tm, &secs);
 74	return secs;
 75}
 76
 77static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
 78{
 79	unsigned long timeout = jiffies + HZ;
 80	int retval, i;
 81	unsigned long mins, secs;
 82	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
 83	u8 value;
 84
 85	/* Request a data read */
 86	retval = abx500_set_register_interruptible(dev,
 87		AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST);
 88	if (retval < 0)
 89		return retval;
 90
 91	/* Early AB8500 chips will not clear the rtc read request bit */
 92	if (abx500_get_chip_id(dev) == 0) {
 93		msleep(1);
 94	} else {
 95		/* Wait for some cycles after enabling the rtc read in ab8500 */
 96		while (time_before(jiffies, timeout)) {
 97			retval = abx500_get_register_interruptible(dev,
 98				AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);
 99			if (retval < 0)
100				return retval;
101
102			if (!(value & RTC_READ_REQUEST))
103				break;
104
105			msleep(1);
106		}
107	}
108
109	/* Read the Watchtime registers */
110	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
111		retval = abx500_get_register_interruptible(dev,
112			AB8500_RTC, ab8500_rtc_time_regs[i], &value);
113		if (retval < 0)
114			return retval;
115		buf[i] = value;
116	}
117
118	mins = (buf[0] << 16) | (buf[1] << 8) | buf[2];
119
120	secs =	(buf[3] << 8) | buf[4];
121	secs =	secs / COUNTS_PER_SEC;
122	secs =	secs + (mins * 60);
123
124	/* Add back the initially subtracted number of seconds */
125	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
126
127	rtc_time_to_tm(secs, tm);
128	return rtc_valid_tm(tm);
129}
130
131static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
132{
133	int retval, i;
134	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
135	unsigned long no_secs, no_mins, secs = 0;
136
137	if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) {
138		dev_dbg(dev, "year should be equal to or greater than %d\n",
139				AB8500_RTC_EPOCH);
140		return -EINVAL;
141	}
142
143	/* Get the number of seconds since 1970 */
144	rtc_tm_to_time(tm, &secs);
145
146	/*
147	 * Convert it to the number of seconds since 01-01-2000 00:00:00, since
148	 * we only have a small counter in the RTC.
149	 */
150	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
151
152	no_mins = secs / 60;
153
154	no_secs = secs % 60;
155	/* Make the seconds count as per the RTC resolution */
156	no_secs = no_secs * COUNTS_PER_SEC;
157
158	buf[4] = no_secs & 0xFF;
159	buf[3] = (no_secs >> 8) & 0xFF;
160
161	buf[2] = no_mins & 0xFF;
162	buf[1] = (no_mins >> 8) & 0xFF;
163	buf[0] = (no_mins >> 16) & 0xFF;
164
165	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
166		retval = abx500_set_register_interruptible(dev, AB8500_RTC,
167			ab8500_rtc_time_regs[i], buf[i]);
168		if (retval < 0)
169			return retval;
170	}
171
172	/* Request a data write */
173	return abx500_set_register_interruptible(dev, AB8500_RTC,
174		AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
175}
176
177static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
178{
179	int retval, i;
180	u8 rtc_ctrl, value;
181	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
182	unsigned long secs, mins;
183
184	/* Check if the alarm is enabled or not */
185	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
186		AB8500_RTC_STAT_REG, &rtc_ctrl);
187	if (retval < 0)
188		return retval;
189
190	if (rtc_ctrl & RTC_ALARM_ENA)
191		alarm->enabled = 1;
192	else
193		alarm->enabled = 0;
194
195	alarm->pending = 0;
196
197	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
198		retval = abx500_get_register_interruptible(dev, AB8500_RTC,
199			ab8500_rtc_alarm_regs[i], &value);
200		if (retval < 0)
201			return retval;
202		buf[i] = value;
203	}
204
205	mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]);
206	secs = mins * 60;
207
208	/* Add back the initially subtracted number of seconds */
209	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
210
211	rtc_time_to_tm(secs, &alarm->time);
212
213	return rtc_valid_tm(&alarm->time);
214}
215
216static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
217{
218	return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,
219		AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
220		enabled ? RTC_ALARM_ENA : 0);
221}
222
223static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
224{
225	int retval, i;
226	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
227	unsigned long mins, secs = 0;
228
229	if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
230		dev_dbg(dev, "year should be equal to or greater than %d\n",
231				AB8500_RTC_EPOCH);
232		return -EINVAL;
233	}
234
235	/* Get the number of seconds since 1970 */
236	rtc_tm_to_time(&alarm->time, &secs);
237
238	/*
239	 * Convert it to the number of seconds since 01-01-2000 00:00:00, since
240	 * we only have a small counter in the RTC.
 
241	 */
242	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
 
 
 
 
 
243
244	mins = secs / 60;
245
246	buf[2] = mins & 0xFF;
247	buf[1] = (mins >> 8) & 0xFF;
248	buf[0] = (mins >> 16) & 0xFF;
249
250	/* Set the alarm time */
251	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
252		retval = abx500_set_register_interruptible(dev, AB8500_RTC,
253			ab8500_rtc_alarm_regs[i], buf[i]);
254		if (retval < 0)
255			return retval;
256	}
257
258	return ab8500_rtc_irq_enable(dev, alarm->enabled);
259}
260
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
261static irqreturn_t rtc_alarm_handler(int irq, void *data)
262{
263	struct rtc_device *rtc = data;
264	unsigned long events = RTC_IRQF | RTC_AF;
265
266	dev_dbg(&rtc->dev, "%s\n", __func__);
267	rtc_update_irq(rtc, 1, events);
268
269	return IRQ_HANDLED;
270}
271
272static const struct rtc_class_ops ab8500_rtc_ops = {
273	.read_time		= ab8500_rtc_read_time,
274	.set_time		= ab8500_rtc_set_time,
275	.read_alarm		= ab8500_rtc_read_alarm,
276	.set_alarm		= ab8500_rtc_set_alarm,
277	.alarm_irq_enable	= ab8500_rtc_irq_enable,
278};
279
280static int __devinit ab8500_rtc_probe(struct platform_device *pdev)
 
 
 
 
 
 
281{
 
282	int err;
283	struct rtc_device *rtc;
284	u8 rtc_ctrl;
285	int irq;
286
287	irq = platform_get_irq_byname(pdev, "ALARM");
288	if (irq < 0)
289		return irq;
290
291	/* For RTC supply test */
292	err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
293		AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
294	if (err < 0)
295		return err;
296
297	/* Wait for reset by the PorRtc */
298	msleep(1);
299
300	err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
301		AB8500_RTC_STAT_REG, &rtc_ctrl);
302	if (err < 0)
303		return err;
304
305	/* Check if the RTC Supply fails */
306	if (!(rtc_ctrl & RTC_STATUS_DATA)) {
307		dev_err(&pdev->dev, "RTC supply failure\n");
308		return -ENODEV;
309	}
310
311	rtc = rtc_device_register("ab8500-rtc", &pdev->dev, &ab8500_rtc_ops,
312			THIS_MODULE);
313	if (IS_ERR(rtc)) {
314		dev_err(&pdev->dev, "Registration failed\n");
315		err = PTR_ERR(rtc);
316		return err;
317	}
318
319	err = request_threaded_irq(irq, NULL, rtc_alarm_handler, 0,
320				   "ab8500-rtc", rtc);
321	if (err < 0) {
322		rtc_device_unregister(rtc);
 
 
 
 
 
 
323		return err;
324	}
325
 
326	platform_set_drvdata(pdev, rtc);
327
328	return 0;
 
 
 
 
 
 
 
 
 
 
329}
330
331static int __devexit ab8500_rtc_remove(struct platform_device *pdev)
332{
333	struct rtc_device *rtc = platform_get_drvdata(pdev);
334	int irq = platform_get_irq_byname(pdev, "ALARM");
335
336	free_irq(irq, rtc);
337	rtc_device_unregister(rtc);
338	platform_set_drvdata(pdev, NULL);
339
340	return 0;
341}
342
343static struct platform_driver ab8500_rtc_driver = {
344	.driver = {
345		.name = "ab8500-rtc",
346		.owner = THIS_MODULE,
347	},
348	.probe	= ab8500_rtc_probe,
349	.remove = __devexit_p(ab8500_rtc_remove),
 
350};
351
352static int __init ab8500_rtc_init(void)
353{
354	return platform_driver_register(&ab8500_rtc_driver);
355}
356
357static void __exit ab8500_rtc_exit(void)
358{
359	platform_driver_unregister(&ab8500_rtc_driver);
360}
361
362module_init(ab8500_rtc_init);
363module_exit(ab8500_rtc_exit);
364MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
365MODULE_DESCRIPTION("AB8500 RTC Driver");
366MODULE_LICENSE("GPL v2");
v5.4
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) ST-Ericsson SA 2010
  4 *
 
  5 * Author: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
  6 *
  7 * RTC clock driver for the RTC part of the AB8500 Power management chip.
  8 * Based on RTC clock driver for the AB3100 Analog Baseband Chip by
  9 * Linus Walleij <linus.walleij@stericsson.com>
 10 */
 11
 12#include <linux/module.h>
 13#include <linux/kernel.h>
 14#include <linux/init.h>
 15#include <linux/platform_device.h>
 16#include <linux/rtc.h>
 17#include <linux/mfd/abx500.h>
 18#include <linux/mfd/abx500/ab8500.h>
 19#include <linux/delay.h>
 20#include <linux/of.h>
 21#include <linux/pm_wakeirq.h>
 22
 23#define AB8500_RTC_SOFF_STAT_REG	0x00
 24#define AB8500_RTC_CC_CONF_REG		0x01
 25#define AB8500_RTC_READ_REQ_REG		0x02
 26#define AB8500_RTC_WATCH_TSECMID_REG	0x03
 27#define AB8500_RTC_WATCH_TSECHI_REG	0x04
 28#define AB8500_RTC_WATCH_TMIN_LOW_REG	0x05
 29#define AB8500_RTC_WATCH_TMIN_MID_REG	0x06
 30#define AB8500_RTC_WATCH_TMIN_HI_REG	0x07
 31#define AB8500_RTC_ALRM_MIN_LOW_REG	0x08
 32#define AB8500_RTC_ALRM_MIN_MID_REG	0x09
 33#define AB8500_RTC_ALRM_MIN_HI_REG	0x0A
 34#define AB8500_RTC_STAT_REG		0x0B
 35#define AB8500_RTC_BKUP_CHG_REG		0x0C
 36#define AB8500_RTC_FORCE_BKUP_REG	0x0D
 37#define AB8500_RTC_CALIB_REG		0x0E
 38#define AB8500_RTC_SWITCH_STAT_REG	0x0F
 39
 40/* RtcReadRequest bits */
 41#define RTC_READ_REQUEST		0x01
 42#define RTC_WRITE_REQUEST		0x02
 43
 44/* RtcCtrl bits */
 45#define RTC_ALARM_ENA			0x04
 46#define RTC_STATUS_DATA			0x01
 47
 48#define COUNTS_PER_SEC			(0xF000 / 60)
 
 49
 50static const u8 ab8500_rtc_time_regs[] = {
 51	AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
 52	AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,
 53	AB8500_RTC_WATCH_TSECMID_REG
 54};
 55
 56static const u8 ab8500_rtc_alarm_regs[] = {
 57	AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,
 58	AB8500_RTC_ALRM_MIN_LOW_REG
 59};
 60
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 61static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
 62{
 63	unsigned long timeout = jiffies + HZ;
 64	int retval, i;
 65	unsigned long mins, secs;
 66	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
 67	u8 value;
 68
 69	/* Request a data read */
 70	retval = abx500_set_register_interruptible(dev,
 71		AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST);
 72	if (retval < 0)
 73		return retval;
 74
 75	/* Wait for some cycles after enabling the rtc read in ab8500 */
 76	while (time_before(jiffies, timeout)) {
 77		retval = abx500_get_register_interruptible(dev,
 78			AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);
 79		if (retval < 0)
 80			return retval;
 
 
 
 
 81
 82		if (!(value & RTC_READ_REQUEST))
 83			break;
 84
 85		usleep_range(1000, 5000);
 
 86	}
 87
 88	/* Read the Watchtime registers */
 89	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
 90		retval = abx500_get_register_interruptible(dev,
 91			AB8500_RTC, ab8500_rtc_time_regs[i], &value);
 92		if (retval < 0)
 93			return retval;
 94		buf[i] = value;
 95	}
 96
 97	mins = (buf[0] << 16) | (buf[1] << 8) | buf[2];
 98
 99	secs =	(buf[3] << 8) | buf[4];
100	secs =	secs / COUNTS_PER_SEC;
101	secs =	secs + (mins * 60);
102
 
 
 
103	rtc_time_to_tm(secs, tm);
104	return 0;
105}
106
107static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
108{
109	int retval, i;
110	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
111	unsigned long no_secs, no_mins, secs = 0;
112
 
 
 
 
 
 
 
113	rtc_tm_to_time(tm, &secs);
114
 
 
 
 
 
 
115	no_mins = secs / 60;
116
117	no_secs = secs % 60;
118	/* Make the seconds count as per the RTC resolution */
119	no_secs = no_secs * COUNTS_PER_SEC;
120
121	buf[4] = no_secs & 0xFF;
122	buf[3] = (no_secs >> 8) & 0xFF;
123
124	buf[2] = no_mins & 0xFF;
125	buf[1] = (no_mins >> 8) & 0xFF;
126	buf[0] = (no_mins >> 16) & 0xFF;
127
128	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
129		retval = abx500_set_register_interruptible(dev, AB8500_RTC,
130			ab8500_rtc_time_regs[i], buf[i]);
131		if (retval < 0)
132			return retval;
133	}
134
135	/* Request a data write */
136	return abx500_set_register_interruptible(dev, AB8500_RTC,
137		AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
138}
139
140static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
141{
142	int retval, i;
143	u8 rtc_ctrl, value;
144	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
145	unsigned long secs, mins;
146
147	/* Check if the alarm is enabled or not */
148	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
149		AB8500_RTC_STAT_REG, &rtc_ctrl);
150	if (retval < 0)
151		return retval;
152
153	if (rtc_ctrl & RTC_ALARM_ENA)
154		alarm->enabled = 1;
155	else
156		alarm->enabled = 0;
157
158	alarm->pending = 0;
159
160	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
161		retval = abx500_get_register_interruptible(dev, AB8500_RTC,
162			ab8500_rtc_alarm_regs[i], &value);
163		if (retval < 0)
164			return retval;
165		buf[i] = value;
166	}
167
168	mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]);
169	secs = mins * 60;
170
 
 
 
171	rtc_time_to_tm(secs, &alarm->time);
172
173	return 0;
174}
175
176static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
177{
178	return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,
179		AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
180		enabled ? RTC_ALARM_ENA : 0);
181}
182
183static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
184{
185	int retval, i;
186	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
187	unsigned long mins, secs = 0, cursec = 0;
188	struct rtc_time curtm;
 
 
 
 
 
189
190	/* Get the number of seconds since 1970 */
191	rtc_tm_to_time(&alarm->time, &secs);
192
193	/*
194	 * Check whether alarm is set less than 1min.
195	 * Since our RTC doesn't support alarm resolution less than 1min,
196	 * return -EINVAL, so UIE EMUL can take it up, incase of UIE_ON
197	 */
198	ab8500_rtc_read_time(dev, &curtm); /* Read current time */
199	rtc_tm_to_time(&curtm, &cursec);
200	if ((secs - cursec) < 59) {
201		dev_dbg(dev, "Alarm less than 1 minute not supported\r\n");
202		return -EINVAL;
203	}
204
205	mins = secs / 60;
206
207	buf[2] = mins & 0xFF;
208	buf[1] = (mins >> 8) & 0xFF;
209	buf[0] = (mins >> 16) & 0xFF;
210
211	/* Set the alarm time */
212	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
213		retval = abx500_set_register_interruptible(dev, AB8500_RTC,
214			ab8500_rtc_alarm_regs[i], buf[i]);
215		if (retval < 0)
216			return retval;
217	}
218
219	return ab8500_rtc_irq_enable(dev, alarm->enabled);
220}
221
222static int ab8500_rtc_set_calibration(struct device *dev, int calibration)
223{
224	int retval;
225	u8  rtccal = 0;
226
227	/*
228	 * Check that the calibration value (which is in units of 0.5
229	 * parts-per-million) is in the AB8500's range for RtcCalibration
230	 * register. -128 (0x80) is not permitted because the AB8500 uses
231	 * a sign-bit rather than two's complement, so 0x80 is just another
232	 * representation of zero.
233	 */
234	if ((calibration < -127) || (calibration > 127)) {
235		dev_err(dev, "RtcCalibration value outside permitted range\n");
236		return -EINVAL;
237	}
238
239	/*
240	 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
241	 * so need to convert to this sort of representation before writing
242	 * into RtcCalibration register...
243	 */
244	if (calibration >= 0)
245		rtccal = 0x7F & calibration;
246	else
247		rtccal = ~(calibration - 1) | 0x80;
248
249	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
250			AB8500_RTC_CALIB_REG, rtccal);
251
252	return retval;
253}
254
255static int ab8500_rtc_get_calibration(struct device *dev, int *calibration)
256{
257	int retval;
258	u8  rtccal = 0;
259
260	retval =  abx500_get_register_interruptible(dev, AB8500_RTC,
261			AB8500_RTC_CALIB_REG, &rtccal);
262	if (retval >= 0) {
263		/*
264		 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
265		 * so need to convert value from RtcCalibration register into
266		 * a two's complement signed value...
267		 */
268		if (rtccal & 0x80)
269			*calibration = 0 - (rtccal & 0x7F);
270		else
271			*calibration = 0x7F & rtccal;
272	}
273
274	return retval;
275}
276
277static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev,
278				struct device_attribute *attr,
279				const char *buf, size_t count)
280{
281	int retval;
282	int calibration = 0;
283
284	if (sscanf(buf, " %i ", &calibration) != 1) {
285		dev_err(dev, "Failed to store RTC calibration attribute\n");
286		return -EINVAL;
287	}
288
289	retval = ab8500_rtc_set_calibration(dev, calibration);
290
291	return retval ? retval : count;
292}
293
294static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev,
295				struct device_attribute *attr, char *buf)
296{
297	int  retval = 0;
298	int  calibration = 0;
299
300	retval = ab8500_rtc_get_calibration(dev, &calibration);
301	if (retval < 0) {
302		dev_err(dev, "Failed to read RTC calibration attribute\n");
303		sprintf(buf, "0\n");
304		return retval;
305	}
306
307	return sprintf(buf, "%d\n", calibration);
308}
309
310static DEVICE_ATTR(rtc_calibration, S_IRUGO | S_IWUSR,
311		   ab8500_sysfs_show_rtc_calibration,
312		   ab8500_sysfs_store_rtc_calibration);
313
314static struct attribute *ab8500_rtc_attrs[] = {
315	&dev_attr_rtc_calibration.attr,
316	NULL
317};
318
319static const struct attribute_group ab8500_rtc_sysfs_files = {
320	.attrs	= ab8500_rtc_attrs,
321};
322
323static irqreturn_t rtc_alarm_handler(int irq, void *data)
324{
325	struct rtc_device *rtc = data;
326	unsigned long events = RTC_IRQF | RTC_AF;
327
328	dev_dbg(&rtc->dev, "%s\n", __func__);
329	rtc_update_irq(rtc, 1, events);
330
331	return IRQ_HANDLED;
332}
333
334static const struct rtc_class_ops ab8500_rtc_ops = {
335	.read_time		= ab8500_rtc_read_time,
336	.set_time		= ab8500_rtc_set_time,
337	.read_alarm		= ab8500_rtc_read_alarm,
338	.set_alarm		= ab8500_rtc_set_alarm,
339	.alarm_irq_enable	= ab8500_rtc_irq_enable,
340};
341
342static const struct platform_device_id ab85xx_rtc_ids[] = {
343	{ "ab8500-rtc", (kernel_ulong_t)&ab8500_rtc_ops, },
344	{ /* sentinel */ }
345};
346MODULE_DEVICE_TABLE(platform, ab85xx_rtc_ids);
347
348static int ab8500_rtc_probe(struct platform_device *pdev)
349{
350	const struct platform_device_id *platid = platform_get_device_id(pdev);
351	int err;
352	struct rtc_device *rtc;
353	u8 rtc_ctrl;
354	int irq;
355
356	irq = platform_get_irq_byname(pdev, "ALARM");
357	if (irq < 0)
358		return irq;
359
360	/* For RTC supply test */
361	err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
362		AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
363	if (err < 0)
364		return err;
365
366	/* Wait for reset by the PorRtc */
367	usleep_range(1000, 5000);
368
369	err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
370		AB8500_RTC_STAT_REG, &rtc_ctrl);
371	if (err < 0)
372		return err;
373
374	/* Check if the RTC Supply fails */
375	if (!(rtc_ctrl & RTC_STATUS_DATA)) {
376		dev_err(&pdev->dev, "RTC supply failure\n");
377		return -ENODEV;
378	}
379
380	device_init_wakeup(&pdev->dev, true);
 
 
 
 
 
 
381
382	rtc = devm_rtc_allocate_device(&pdev->dev);
383	if (IS_ERR(rtc))
384		return PTR_ERR(rtc);
385
386	rtc->ops = (struct rtc_class_ops *)platid->driver_data;
387
388	err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
389			rtc_alarm_handler, IRQF_ONESHOT,
390			"ab8500-rtc", rtc);
391	if (err < 0)
392		return err;
 
393
394	dev_pm_set_wake_irq(&pdev->dev, irq);
395	platform_set_drvdata(pdev, rtc);
396
397	rtc->uie_unsupported = 1;
398
399	rtc->range_max = (1ULL << 24) * 60 - 1; // 24-bit minutes + 59 secs
400	rtc->start_secs = RTC_TIMESTAMP_BEGIN_2000;
401	rtc->set_start_time = true;
402
403	err = rtc_add_group(rtc, &ab8500_rtc_sysfs_files);
404	if (err)
405		return err;
406
407	return rtc_register_device(rtc);
408}
409
410static int ab8500_rtc_remove(struct platform_device *pdev)
411{
412	dev_pm_clear_wake_irq(&pdev->dev);
413	device_init_wakeup(&pdev->dev, false);
 
 
 
 
414
415	return 0;
416}
417
418static struct platform_driver ab8500_rtc_driver = {
419	.driver = {
420		.name = "ab8500-rtc",
 
421	},
422	.probe	= ab8500_rtc_probe,
423	.remove = ab8500_rtc_remove,
424	.id_table = ab85xx_rtc_ids,
425};
426
427module_platform_driver(ab8500_rtc_driver);
 
 
 
 
 
 
 
 
428
 
 
429MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
430MODULE_DESCRIPTION("AB8500 RTC Driver");
431MODULE_LICENSE("GPL v2");