1 // SPDX-License-Identifier: GPL-2.0
3  * Driver for the RTC found in the SpacemiT P1 PMIC
15 #define MOD_NAME	"spacemit-p1-rtc"
18  * Six consecutive 1-byte registers hold the seconds, minutes, hours,
19  * day-of-month, month, and year (respectively).
22  *    seconds	0-59
23  *    minutes	0-59
24  *    hours	0-59
25  *    day	0-30 (struct tm is 1-31)
26  *    month	0-11
46  * The P1 hardware documentation states that the register values are
53 	struct p1_rtc *p1 = dev_get_drvdata(dev);  in p1_rtc_read_time()  local
54 	struct regmap *regmap = p1->regmap;  in p1_rtc_read_time()
61 		return -EINVAL;		/* RTC is disabled */  in p1_rtc_read_time()
72 	} while (time[0] != seconds && --count);  in p1_rtc_read_time()
75 		return -EIO;		/* Unable to get a consistent result */  in p1_rtc_read_time()
77 	t->tm_sec = time[0] & GENMASK(5, 0);  in p1_rtc_read_time()
78 	t->tm_min = time[1] & GENMASK(5, 0);  in p1_rtc_read_time()
79 	t->tm_hour = time[2] & GENMASK(4, 0);  in p1_rtc_read_time()
80 	t->tm_mday = (time[3] & GENMASK(4, 0)) + 1;  in p1_rtc_read_time()
81 	t->tm_mon = time[4] & GENMASK(3, 0);  in p1_rtc_read_time()
82 	t->tm_year = (time[5] & GENMASK(5, 0)) + 100;  in p1_rtc_read_time()
88  * The P1 hardware documentation states that values in the registers are
95 	struct p1_rtc *p1 = dev_get_drvdata(dev);  in p1_rtc_set_time()  local
96 	struct regmap *regmap = p1->regmap;  in p1_rtc_set_time()
100 	time[0] = t->tm_sec;  in p1_rtc_set_time()
101 	time[1] = t->tm_min;  in p1_rtc_set_time()
102 	time[2] = t->tm_hour;  in p1_rtc_set_time()
103 	time[3] = t->tm_mday - 1;  in p1_rtc_set_time()
104 	time[4] = t->tm_mon;  in p1_rtc_set_time()
105 	time[5] = t->tm_year - 100;  in p1_rtc_set_time()
107 	/* Disable the RTC to update; re-enable again when done */  in p1_rtc_set_time()
127 	struct device *dev = &pdev->dev;  in p1_rtc_probe()
129 	struct p1_rtc *p1;  in p1_rtc_probe()  local
131 	p1 = devm_kzalloc(dev, sizeof(*p1), GFP_KERNEL);  in p1_rtc_probe()
132 	if (!p1)  in p1_rtc_probe()
133 		return -ENOMEM;  in p1_rtc_probe()
134 	dev_set_drvdata(dev, p1);  in p1_rtc_probe()
136 	p1->regmap = dev_get_regmap(dev->parent, NULL);  in p1_rtc_probe()
137 	if (!p1->regmap)  in p1_rtc_probe()
138 		return dev_err_probe(dev, -ENODEV, "failed to get regmap\n");  in p1_rtc_probe()
144 	p1->rtc = rtc;  in p1_rtc_probe()
146 	rtc->ops = &p1_rtc_class_ops;  in p1_rtc_probe()
147 	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;  in p1_rtc_probe()
148 	rtc->range_max = RTC_TIMESTAMP_END_2063;  in p1_rtc_probe()
150 	clear_bit(RTC_FEATURE_ALARM, rtc->features);  in p1_rtc_probe()
151 	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);  in p1_rtc_probe()
165 MODULE_DESCRIPTION("SpacemiT P1 RTC driver");