summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-nxp-bbnsm.c
blob: acbfbeb8b0700708464867d3395f890dd77271ed (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
// SPDX-License-Identifier: GPL-2.0+
//
// Copyright 2022 NXP.

#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_wakeirq.h>
#include <linux/regmap.h>
#include <linux/rtc.h>

#define BBNSM_CTRL	0x8
#define BBNSM_INT_EN	0x10
#define BBNSM_EVENTS	0x14
#define BBNSM_RTC_LS	0x40
#define BBNSM_RTC_MS	0x44
#define BBNSM_TA	0x50

#define RTC_EN		0x2
#define RTC_EN_MSK	0x3
#define TA_EN		(0x2 << 2)
#define TA_DIS		(0x1 << 2)
#define TA_EN_MSK	(0x3 << 2)
#define RTC_INT_EN	0x2
#define TA_INT_EN	(0x2 << 2)

#define BBNSM_EVENT_TA	(0x2 << 2)

#define CNTR_TO_SECS_SH	15

struct bbnsm_rtc {
	struct rtc_device *rtc;
	struct regmap *regmap;
	int irq;
	struct clk *clk;
};

static u32 bbnsm_read_counter(struct bbnsm_rtc *bbnsm)
{
	u32 rtc_msb, rtc_lsb;
	unsigned int timeout = 100;
	u32 time;
	u32 tmp = 0;

	do {
		time = tmp;
		/* read the msb */
		regmap_read(bbnsm->regmap, BBNSM_RTC_MS, &rtc_msb);
		/* read the lsb */
		regmap_read(bbnsm->regmap, BBNSM_RTC_LS, &rtc_lsb);
		/* convert to seconds */
		tmp = (rtc_msb << 17) | (rtc_lsb >> 15);
	} while (tmp != time && --timeout);

	return time;
}

static int bbnsm_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);
	unsigned long time;
	u32 val;

	regmap_read(bbnsm->regmap, BBNSM_CTRL, &val);
	if ((val & RTC_EN_MSK) != RTC_EN)
		return -EINVAL;

	time = bbnsm_read_counter(bbnsm);
	rtc_time64_to_tm(time, tm);

	return 0;
}

static int bbnsm_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);
	unsigned long time = rtc_tm_to_time64(tm);

	/* disable the RTC first */
	regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, RTC_EN_MSK, 0);

	/* write the 32bit sec time to 47 bit timer counter, leaving 15 LSBs blank */
	regmap_write(bbnsm->regmap, BBNSM_RTC_LS, time << CNTR_TO_SECS_SH);
	regmap_write(bbnsm->regmap, BBNSM_RTC_MS, time >> (32 - CNTR_TO_SECS_SH));

	/* Enable the RTC again */
	regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, RTC_EN_MSK, RTC_EN);

	return 0;
}

static int bbnsm_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);
	u32 bbnsm_events, bbnsm_ta;

	regmap_read(bbnsm->regmap, BBNSM_TA, &bbnsm_ta);
	rtc_time64_to_tm(bbnsm_ta, &alrm->time);

	regmap_read(bbnsm->regmap, BBNSM_EVENTS, &bbnsm_events);
	alrm->pending = (bbnsm_events & BBNSM_EVENT_TA) ? 1 : 0;

	return 0;
}

static int bbnsm_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
{
	struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);

	/* enable the alarm event */
	regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, TA_EN_MSK, enable ? TA_EN : TA_DIS);
	/* enable the alarm interrupt */
	regmap_update_bits(bbnsm->regmap, BBNSM_INT_EN, TA_EN_MSK, enable ? TA_EN : TA_DIS);

	return 0;
}

static int bbnsm_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);
	unsigned long time = rtc_tm_to_time64(&alrm->time);

	/* disable the alarm */
	regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, TA_EN, TA_EN);

	/* write the seconds to TA */
	regmap_write(bbnsm->regmap, BBNSM_TA, time);

	return bbnsm_rtc_alarm_irq_enable(dev, alrm->enabled);
}

static const struct rtc_class_ops bbnsm_rtc_ops = {
	.read_time = bbnsm_rtc_read_time,
	.set_time = bbnsm_rtc_set_time,
	.read_alarm = bbnsm_rtc_read_alarm,
	.set_alarm = bbnsm_rtc_set_alarm,
	.alarm_irq_enable = bbnsm_rtc_alarm_irq_enable,
};

static irqreturn_t bbnsm_rtc_irq_handler(int irq, void *dev_id)
{
	struct device *dev = dev_id;
	struct bbnsm_rtc  *bbnsm = dev_get_drvdata(dev);
	u32 val;

	regmap_read(bbnsm->regmap, BBNSM_EVENTS, &val);
	if (val & BBNSM_EVENT_TA) {
		bbnsm_rtc_alarm_irq_enable(dev, false);
		/* clear the alarm event */
		regmap_write_bits(bbnsm->regmap, BBNSM_EVENTS, TA_EN_MSK, BBNSM_EVENT_TA);
		rtc_update_irq(bbnsm->rtc, 1, RTC_AF | RTC_IRQF);

		return IRQ_HANDLED;
	}

	return IRQ_NONE;
}

static int bbnsm_rtc_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct bbnsm_rtc *bbnsm;
	int ret;

	bbnsm = devm_kzalloc(&pdev->dev, sizeof(*bbnsm), GFP_KERNEL);
	if (!bbnsm)
		return -ENOMEM;

	bbnsm->rtc = devm_rtc_allocate_device(&pdev->dev);
	if (IS_ERR(bbnsm->rtc))
		return PTR_ERR(bbnsm->rtc);

	bbnsm->regmap = syscon_node_to_regmap(np->parent);
	if (IS_ERR(bbnsm->regmap)) {
		dev_dbg(&pdev->dev, "bbnsm get regmap failed\n");
		return PTR_ERR(bbnsm->regmap);
	}

	bbnsm->irq = platform_get_irq(pdev, 0);
	if (bbnsm->irq < 0)
		return bbnsm->irq;

	platform_set_drvdata(pdev, bbnsm);

	/* clear all the pending events */
	regmap_write(bbnsm->regmap, BBNSM_EVENTS, 0x7A);

	device_init_wakeup(&pdev->dev, true);
	dev_pm_set_wake_irq(&pdev->dev, bbnsm->irq);

	ret = devm_request_irq(&pdev->dev, bbnsm->irq, bbnsm_rtc_irq_handler,
			       IRQF_SHARED, "rtc alarm", &pdev->dev);
	if (ret) {
		dev_err(&pdev->dev, "failed to request irq %d: %d\n",
			bbnsm->irq, ret);
		return ret;
	}

	bbnsm->rtc->ops = &bbnsm_rtc_ops;
	bbnsm->rtc->range_max = U32_MAX;

	return devm_rtc_register_device(bbnsm->rtc);
}

static const struct of_device_id bbnsm_dt_ids[] = {
	{ .compatible = "nxp,imx93-bbnsm-rtc" },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, bbnsm_dt_ids);

static struct platform_driver bbnsm_rtc_driver = {
	.driver = {
		.name = "bbnsm_rtc",
		.of_match_table = bbnsm_dt_ids,
	},
	.probe = bbnsm_rtc_probe,
};
module_platform_driver(bbnsm_rtc_driver);

MODULE_AUTHOR("Jacky Bai <ping.bai@nxp.com>");
MODULE_DESCRIPTION("NXP BBNSM RTC Driver");
MODULE_LICENSE("GPL");