rtc-palmas.c revision 2c5a5b30917b725ea95fa189e52fc8412f6a2814 
1/*
2 * rtc-palmas.c -- Palmas Real Time Clock driver.
3
4 * RTC driver for TI Palma series devices like TPS65913,
5 * TPS65914 power management IC.
6 *
7 * Copyright (c) 2012, NVIDIA Corporation.
8 *
9 * Author: Laxman Dewangan <ldewangan@nvidia.com>
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation version 2.
14 *
15 * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
16 * whether express or implied; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
23 * 02111-1307, USA
24 */
25
26#include <linux/bcd.h>
27#include <linux/errno.h>
28#include <linux/init.h>
29#include <linux/interrupt.h>
30#include <linux/kernel.h>
31#include <linux/mfd/palmas.h>
32#include <linux/module.h>
33#include <linux/of.h>
34#include <linux/rtc.h>
35#include <linux/types.h>
36#include <linux/platform_device.h>
37#include <linux/pm.h>
38
39struct palmas_rtc {
40	struct rtc_device	*rtc;
41	struct device		*dev;
42	unsigned int		irq;
43};
44
45/* Total number of RTC registers needed to set time*/
46#define PALMAS_NUM_TIME_REGS	(PALMAS_YEARS_REG - PALMAS_SECONDS_REG + 1)
47
48static int palmas_rtc_read_time(struct device *dev, struct rtc_time *tm)
49{
50	unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
51	struct palmas *palmas = dev_get_drvdata(dev->parent);
52	int ret;
53
54	/* Copy RTC counting registers to static registers or latches */
55	ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
56		PALMAS_RTC_CTRL_REG_GET_TIME, PALMAS_RTC_CTRL_REG_GET_TIME);
57	if (ret < 0) {
58		dev_err(dev, "RTC CTRL reg update failed, err: %d\n", ret);
59		return ret;
60	}
61
62	ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
63			rtc_data, PALMAS_NUM_TIME_REGS);
64	if (ret < 0) {
65		dev_err(dev, "RTC_SECONDS reg read failed, err = %d\n", ret);
66		return ret;
67	}
68
69	tm->tm_sec = bcd2bin(rtc_data[0]);
70	tm->tm_min = bcd2bin(rtc_data[1]);
71	tm->tm_hour = bcd2bin(rtc_data[2]);
72	tm->tm_mday = bcd2bin(rtc_data[3]);
73	tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
74	tm->tm_year = bcd2bin(rtc_data[5]) + 100;
75
76	return ret;
77}
78
79static int palmas_rtc_set_time(struct device *dev, struct rtc_time *tm)
80{
81	unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
82	struct palmas *palmas = dev_get_drvdata(dev->parent);
83	int ret;
84
85	rtc_data[0] = bin2bcd(tm->tm_sec);
86	rtc_data[1] = bin2bcd(tm->tm_min);
87	rtc_data[2] = bin2bcd(tm->tm_hour);
88	rtc_data[3] = bin2bcd(tm->tm_mday);
89	rtc_data[4] = bin2bcd(tm->tm_mon + 1);
90	rtc_data[5] = bin2bcd(tm->tm_year - 100);
91
92	/* Stop RTC while updating the RTC time registers */
93	ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
94		PALMAS_RTC_CTRL_REG_STOP_RTC, 0);
95	if (ret < 0) {
96		dev_err(dev, "RTC stop failed, err = %d\n", ret);
97		return ret;
98	}
99
100	ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
101		rtc_data, PALMAS_NUM_TIME_REGS);
102	if (ret < 0) {
103		dev_err(dev, "RTC_SECONDS reg write failed, err = %d\n", ret);
104		return ret;
105	}
106
107	/* Start back RTC */
108	ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
109		PALMAS_RTC_CTRL_REG_STOP_RTC, PALMAS_RTC_CTRL_REG_STOP_RTC);
110	if (ret < 0)
111		dev_err(dev, "RTC start failed, err = %d\n", ret);
112	return ret;
113}
114
115static int palmas_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
116{
117	struct palmas *palmas = dev_get_drvdata(dev->parent);
118	u8 val;
119
120	val = enabled ? PALMAS_RTC_INTERRUPTS_REG_IT_ALARM : 0;
121	return palmas_write(palmas, PALMAS_RTC_BASE,
122		PALMAS_RTC_INTERRUPTS_REG, val);
123}
124
125static int palmas_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
126{
127	unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
128	u32 int_val;
129	struct palmas *palmas = dev_get_drvdata(dev->parent);
130	int ret;
131
132	ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE,
133			PALMAS_ALARM_SECONDS_REG,
134			alarm_data, PALMAS_NUM_TIME_REGS);
135	if (ret < 0) {
136		dev_err(dev, "RTC_ALARM_SECONDS read failed, err = %d\n", ret);
137		return ret;
138	}
139
140	alm->time.tm_sec = bcd2bin(alarm_data[0]);
141	alm->time.tm_min = bcd2bin(alarm_data[1]);
142	alm->time.tm_hour = bcd2bin(alarm_data[2]);
143	alm->time.tm_mday = bcd2bin(alarm_data[3]);
144	alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
145	alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;
146
147	ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_INTERRUPTS_REG,
148			&int_val);
149	if (ret < 0) {
150		dev_err(dev, "RTC_INTERRUPTS reg read failed, err = %d\n", ret);
151		return ret;
152	}
153
154	if (int_val & PALMAS_RTC_INTERRUPTS_REG_IT_ALARM)
155		alm->enabled = 1;
156	return ret;
157}
158
159static int palmas_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
160{
161	unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
162	struct palmas *palmas = dev_get_drvdata(dev->parent);
163	int ret;
164
165	ret = palmas_rtc_alarm_irq_enable(dev, 0);
166	if (ret < 0) {
167		dev_err(dev, "Disable RTC alarm failed\n");
168		return ret;
169	}
170
171	alarm_data[0] = bin2bcd(alm->time.tm_sec);
172	alarm_data[1] = bin2bcd(alm->time.tm_min);
173	alarm_data[2] = bin2bcd(alm->time.tm_hour);
174	alarm_data[3] = bin2bcd(alm->time.tm_mday);
175	alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
176	alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
177
178	ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE,
179		PALMAS_ALARM_SECONDS_REG, alarm_data, PALMAS_NUM_TIME_REGS);
180	if (ret < 0) {
181		dev_err(dev, "ALARM_SECONDS_REG write failed, err = %d\n", ret);
182		return ret;
183	}
184
185	if (alm->enabled)
186		ret = palmas_rtc_alarm_irq_enable(dev, 1);
187	return ret;
188}
189
190static int palmas_clear_interrupts(struct device *dev)
191{
192	struct palmas *palmas = dev_get_drvdata(dev->parent);
193	unsigned int rtc_reg;
194	int ret;
195
196	ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
197				&rtc_reg);
198	if (ret < 0) {
199		dev_err(dev, "RTC_STATUS read failed, err = %d\n", ret);
200		return ret;
201	}
202
203	ret = palmas_write(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
204			rtc_reg);
205	if (ret < 0) {
206		dev_err(dev, "RTC_STATUS write failed, err = %d\n", ret);
207		return ret;
208	}
209	return 0;
210}
211
212static irqreturn_t palmas_rtc_interrupt(int irq, void *context)
213{
214	struct palmas_rtc *palmas_rtc = context;
215	struct device *dev = palmas_rtc->dev;
216	int ret;
217
218	ret = palmas_clear_interrupts(dev);
219	if (ret < 0) {
220		dev_err(dev, "RTC interrupt clear failed, err = %d\n", ret);
221		return IRQ_NONE;
222	}
223
224	rtc_update_irq(palmas_rtc->rtc, 1, RTC_IRQF | RTC_AF);
225	return IRQ_HANDLED;
226}
227
228static struct rtc_class_ops palmas_rtc_ops = {
229	.read_time	= palmas_rtc_read_time,
230	.set_time	= palmas_rtc_set_time,
231	.read_alarm	= palmas_rtc_read_alarm,
232	.set_alarm	= palmas_rtc_set_alarm,
233	.alarm_irq_enable = palmas_rtc_alarm_irq_enable,
234};
235
236static int palmas_rtc_probe(struct platform_device *pdev)
237{
238	struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
239	struct palmas_rtc *palmas_rtc = NULL;
240	int ret;
241
242	palmas_rtc = devm_kzalloc(&pdev->dev, sizeof(struct palmas_rtc),
243			GFP_KERNEL);
244	if (!palmas_rtc)
245		return -ENOMEM;
246
247	/* Clear pending interrupts */
248	ret = palmas_clear_interrupts(&pdev->dev);
249	if (ret < 0) {
250		dev_err(&pdev->dev, "clear RTC int failed, err = %d\n", ret);
251		return ret;
252	}
253
254	palmas_rtc->dev = &pdev->dev;
255	platform_set_drvdata(pdev, palmas_rtc);
256
257	/* Start RTC */
258	ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
259			PALMAS_RTC_CTRL_REG_STOP_RTC,
260			PALMAS_RTC_CTRL_REG_STOP_RTC);
261	if (ret < 0) {
262		dev_err(&pdev->dev, "RTC_CTRL write failed, err = %d\n", ret);
263		return ret;
264	}
265
266	palmas_rtc->irq = platform_get_irq(pdev, 0);
267
268	device_init_wakeup(&pdev->dev, 1);
269	palmas_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
270				&palmas_rtc_ops, THIS_MODULE);
271	if (IS_ERR(palmas_rtc->rtc)) {
272		ret = PTR_ERR(palmas_rtc->rtc);
273		dev_err(&pdev->dev, "RTC register failed, err = %d\n", ret);
274		return ret;
275	}
276
277	ret = devm_request_threaded_irq(&pdev->dev, palmas_rtc->irq, NULL,
278			palmas_rtc_interrupt,
279			IRQF_TRIGGER_LOW | IRQF_ONESHOT |
280			IRQF_EARLY_RESUME,
281			dev_name(&pdev->dev), palmas_rtc);
282	if (ret < 0) {
283		dev_err(&pdev->dev, "IRQ request failed, err = %d\n", ret);
284		return ret;
285	}
286
287	return 0;
288}
289
290static int palmas_rtc_remove(struct platform_device *pdev)
291{
292	palmas_rtc_alarm_irq_enable(&pdev->dev, 0);
293	return 0;
294}
295
296#ifdef CONFIG_PM_SLEEP
297static int palmas_rtc_suspend(struct device *dev)
298{
299	struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
300
301	if (device_may_wakeup(dev))
302		enable_irq_wake(palmas_rtc->irq);
303	return 0;
304}
305
306static int palmas_rtc_resume(struct device *dev)
307{
308	struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
309
310	if (device_may_wakeup(dev))
311		disable_irq_wake(palmas_rtc->irq);
312	return 0;
313}
314#endif
315
316static const struct dev_pm_ops palmas_rtc_pm_ops = {
317	SET_SYSTEM_SLEEP_PM_OPS(palmas_rtc_suspend, palmas_rtc_resume)
318};
319
320#ifdef CONFIG_OF
321static struct of_device_id of_palmas_rtc_match[] = {
322	{ .compatible = "ti,palmas-rtc"},
323	{ },
324};
325MODULE_DEVICE_TABLE(of, of_palmas_rtc_match);
326#endif
327
328static struct platform_driver palmas_rtc_driver = {
329	.probe		= palmas_rtc_probe,
330	.remove		= palmas_rtc_remove,
331	.driver		= {
332		.owner	= THIS_MODULE,
333		.name	= "palmas-rtc",
334		.pm	= &palmas_rtc_pm_ops,
335		.of_match_table = of_match_ptr(of_palmas_rtc_match),
336	},
337};
338
339module_platform_driver(palmas_rtc_driver);
340
341MODULE_ALIAS("platform:palmas_rtc");
342MODULE_DESCRIPTION("TI PALMAS series RTC driver");
343MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
344MODULE_LICENSE("GPL v2");
345