rtc-palmas.c revision 27971335ce666feb08344ca7c5fdd25f13985f62 
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/rtc.h>
34#include <linux/types.h>
35#include <linux/platform_device.h>
36#include <linux/pm.h>
37
38struct palmas_rtc {
39	struct rtc_device	*rtc;
40	struct device		*dev;
41	unsigned int		irq;
42};
43
44/* Total number of RTC registers needed to set time*/
45#define PALMAS_NUM_TIME_REGS	(PALMAS_YEARS_REG - PALMAS_SECONDS_REG + 1)
46
47static int palmas_rtc_read_time(struct device *dev, struct rtc_time *tm)
48{
49	unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
50	struct palmas *palmas = dev_get_drvdata(dev->parent);
51	int ret;
52
53	/* Copy RTC counting registers to static registers or latches */
54	ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
55		PALMAS_RTC_CTRL_REG_GET_TIME, PALMAS_RTC_CTRL_REG_GET_TIME);
56	if (ret < 0) {
57		dev_err(dev, "RTC CTRL reg update failed, err: %d\n", ret);
58		return ret;
59	}
60
61	ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
62			rtc_data, PALMAS_NUM_TIME_REGS);
63	if (ret < 0) {
64		dev_err(dev, "RTC_SECONDS reg read failed, err = %d\n", ret);
65		return ret;
66	}
67
68	tm->tm_sec = bcd2bin(rtc_data[0]);
69	tm->tm_min = bcd2bin(rtc_data[1]);
70	tm->tm_hour = bcd2bin(rtc_data[2]);
71	tm->tm_mday = bcd2bin(rtc_data[3]);
72	tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
73	tm->tm_year = bcd2bin(rtc_data[5]) + 100;
74
75	return ret;
76}
77
78static int palmas_rtc_set_time(struct device *dev, struct rtc_time *tm)
79{
80	unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
81	struct palmas *palmas = dev_get_drvdata(dev->parent);
82	int ret;
83
84	rtc_data[0] = bin2bcd(tm->tm_sec);
85	rtc_data[1] = bin2bcd(tm->tm_min);
86	rtc_data[2] = bin2bcd(tm->tm_hour);
87	rtc_data[3] = bin2bcd(tm->tm_mday);
88	rtc_data[4] = bin2bcd(tm->tm_mon + 1);
89	rtc_data[5] = bin2bcd(tm->tm_year - 100);
90
91	/* Stop RTC while updating the RTC time registers */
92	ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
93		PALMAS_RTC_CTRL_REG_STOP_RTC, 0);
94	if (ret < 0) {
95		dev_err(dev, "RTC stop failed, err = %d\n", ret);
96		return ret;
97	}
98
99	ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
100		rtc_data, PALMAS_NUM_TIME_REGS);
101	if (ret < 0) {
102		dev_err(dev, "RTC_SECONDS reg write failed, err = %d\n", ret);
103		return ret;
104	}
105
106	/* Start back RTC */
107	ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
108		PALMAS_RTC_CTRL_REG_STOP_RTC, PALMAS_RTC_CTRL_REG_STOP_RTC);
109	if (ret < 0)
110		dev_err(dev, "RTC start failed, err = %d\n", ret);
111	return ret;
112}
113
114static int palmas_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
115{
116	struct palmas *palmas = dev_get_drvdata(dev->parent);
117	u8 val;
118
119	val = enabled ? PALMAS_RTC_INTERRUPTS_REG_IT_ALARM : 0;
120	return palmas_write(palmas, PALMAS_RTC_BASE,
121		PALMAS_RTC_INTERRUPTS_REG, val);
122}
123
124static int palmas_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
125{
126	unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
127	u32 int_val;
128	struct palmas *palmas = dev_get_drvdata(dev->parent);
129	int ret;
130
131	ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE,
132			PALMAS_ALARM_SECONDS_REG,
133			alarm_data, PALMAS_NUM_TIME_REGS);
134	if (ret < 0) {
135		dev_err(dev, "RTC_ALARM_SECONDS read failed, err = %d\n", ret);
136		return ret;
137	}
138
139	alm->time.tm_sec = bcd2bin(alarm_data[0]);
140	alm->time.tm_min = bcd2bin(alarm_data[1]);
141	alm->time.tm_hour = bcd2bin(alarm_data[2]);
142	alm->time.tm_mday = bcd2bin(alarm_data[3]);
143	alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
144	alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;
145
146	ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_INTERRUPTS_REG,
147			&int_val);
148	if (ret < 0) {
149		dev_err(dev, "RTC_INTERRUPTS reg read failed, err = %d\n", ret);
150		return ret;
151	}
152
153	if (int_val & PALMAS_RTC_INTERRUPTS_REG_IT_ALARM)
154		alm->enabled = 1;
155	return ret;
156}
157
158static int palmas_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
159{
160	unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
161	struct palmas *palmas = dev_get_drvdata(dev->parent);
162	int ret;
163
164	ret = palmas_rtc_alarm_irq_enable(dev, 0);
165	if (ret < 0) {
166		dev_err(dev, "Disable RTC alarm failed\n");
167		return ret;
168	}
169
170	alarm_data[0] = bin2bcd(alm->time.tm_sec);
171	alarm_data[1] = bin2bcd(alm->time.tm_min);
172	alarm_data[2] = bin2bcd(alm->time.tm_hour);
173	alarm_data[3] = bin2bcd(alm->time.tm_mday);
174	alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
175	alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
176
177	ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE,
178		PALMAS_ALARM_SECONDS_REG, alarm_data, PALMAS_NUM_TIME_REGS);
179	if (ret < 0) {
180		dev_err(dev, "ALARM_SECONDS_REG write failed, err = %d\n", ret);
181		return ret;
182	}
183
184	if (alm->enabled)
185		ret = palmas_rtc_alarm_irq_enable(dev, 1);
186	return ret;
187}
188
189static int palmas_clear_interrupts(struct device *dev)
190{
191	struct palmas *palmas = dev_get_drvdata(dev->parent);
192	unsigned int rtc_reg;
193	int ret;
194
195	ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
196				&rtc_reg);
197	if (ret < 0) {
198		dev_err(dev, "RTC_STATUS read failed, err = %d\n", ret);
199		return ret;
200	}
201
202	ret = palmas_write(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
203			rtc_reg);
204	if (ret < 0) {
205		dev_err(dev, "RTC_STATUS write failed, err = %d\n", ret);
206		return ret;
207	}
208	return 0;
209}
210
211static irqreturn_t palmas_rtc_interrupt(int irq, void *context)
212{
213	struct palmas_rtc *palmas_rtc = context;
214	struct device *dev = palmas_rtc->dev;
215	int ret;
216
217	ret = palmas_clear_interrupts(dev);
218	if (ret < 0) {
219		dev_err(dev, "RTC interrupt clear failed, err = %d\n", ret);
220		return IRQ_NONE;
221	}
222
223	rtc_update_irq(palmas_rtc->rtc, 1, RTC_IRQF | RTC_AF);
224	return IRQ_HANDLED;
225}
226
227static struct rtc_class_ops palmas_rtc_ops = {
228	.read_time	= palmas_rtc_read_time,
229	.set_time	= palmas_rtc_set_time,
230	.read_alarm	= palmas_rtc_read_alarm,
231	.set_alarm	= palmas_rtc_set_alarm,
232	.alarm_irq_enable = palmas_rtc_alarm_irq_enable,
233};
234
235static int palmas_rtc_probe(struct platform_device *pdev)
236{
237	struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
238	struct palmas_rtc *palmas_rtc = NULL;
239	int ret;
240
241	palmas_rtc = devm_kzalloc(&pdev->dev, sizeof(struct palmas_rtc),
242			GFP_KERNEL);
243	if (!palmas_rtc)
244		return -ENOMEM;
245
246	/* Clear pending interrupts */
247	ret = palmas_clear_interrupts(&pdev->dev);
248	if (ret < 0) {
249		dev_err(&pdev->dev, "clear RTC int failed, err = %d\n", ret);
250		return ret;
251	}
252
253	palmas_rtc->dev = &pdev->dev;
254	platform_set_drvdata(pdev, palmas_rtc);
255
256	/* Start RTC */
257	ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
258			PALMAS_RTC_CTRL_REG_STOP_RTC,
259			PALMAS_RTC_CTRL_REG_STOP_RTC);
260	if (ret < 0) {
261		dev_err(&pdev->dev, "RTC_CTRL write failed, err = %d\n", ret);
262		return ret;
263	}
264
265	palmas_rtc->irq = platform_get_irq(pdev, 0);
266
267	palmas_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
268				&palmas_rtc_ops, THIS_MODULE);
269	if (IS_ERR(palmas_rtc->rtc)) {
270		ret = PTR_ERR(palmas_rtc->rtc);
271		dev_err(&pdev->dev, "RTC register failed, err = %d\n", ret);
272		return ret;
273	}
274
275	ret = devm_request_threaded_irq(&pdev->dev, palmas_rtc->irq, NULL,
276			palmas_rtc_interrupt,
277			IRQF_TRIGGER_LOW | IRQF_ONESHOT |
278			IRQF_EARLY_RESUME,
279			dev_name(&pdev->dev), palmas_rtc);
280	if (ret < 0) {
281		dev_err(&pdev->dev, "IRQ request failed, err = %d\n", ret);
282		return ret;
283	}
284
285	device_set_wakeup_capable(&pdev->dev, 1);
286	return 0;
287}
288
289static int palmas_rtc_remove(struct platform_device *pdev)
290{
291	palmas_rtc_alarm_irq_enable(&pdev->dev, 0);
292	return 0;
293}
294
295#ifdef CONFIG_PM_SLEEP
296static int palmas_rtc_suspend(struct device *dev)
297{
298	struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
299
300	if (device_may_wakeup(dev))
301		enable_irq_wake(palmas_rtc->irq);
302	return 0;
303}
304
305static int palmas_rtc_resume(struct device *dev)
306{
307	struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
308
309	if (device_may_wakeup(dev))
310		disable_irq_wake(palmas_rtc->irq);
311	return 0;
312}
313#endif
314
315static const struct dev_pm_ops palmas_rtc_pm_ops = {
316	SET_SYSTEM_SLEEP_PM_OPS(palmas_rtc_suspend, palmas_rtc_resume)
317};
318
319static struct platform_driver palmas_rtc_driver = {
320	.probe		= palmas_rtc_probe,
321	.remove		= palmas_rtc_remove,
322	.driver		= {
323		.owner	= THIS_MODULE,
324		.name	= "palmas-rtc",
325		.pm	= &palmas_rtc_pm_ops,
326	},
327};
328
329module_platform_driver(palmas_rtc_driver);
330
331MODULE_ALIAS("platform:palmas_rtc");
332MODULE_DESCRIPTION("TI PALMAS series RTC driver");
333MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
334MODULE_LICENSE("GPL v2");
335