1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * Driver for the SGS-Thomson M48T35 Timekeeper RAM chip
28 	u8	year;  member
40 	u8	year;  member
64 	 * by the RTC when initially set to a non-zero value.  in m48t35_read_time()
66 	spin_lock_irq(&priv->lock);  in m48t35_read_time()
67 	control = readb(&priv->reg->control);  in m48t35_read_time()
68 	writeb(control | M48T35_RTC_READ, &priv->reg->control);  in m48t35_read_time()
69 	tm->tm_sec = readb(&priv->reg->sec);  in m48t35_read_time()
70 	tm->tm_min = readb(&priv->reg->min);  in m48t35_read_time()
71 	tm->tm_hour = readb(&priv->reg->hour);  in m48t35_read_time()
72 	tm->tm_mday = readb(&priv->reg->date);  in m48t35_read_time()
73 	tm->tm_mon = readb(&priv->reg->month);  in m48t35_read_time()
74 	tm->tm_year = readb(&priv->reg->year);  in m48t35_read_time()
75 	writeb(control, &priv->reg->control);  in m48t35_read_time()
76 	spin_unlock_irq(&priv->lock);  in m48t35_read_time()
78 	tm->tm_sec = bcd2bin(tm->tm_sec);  in m48t35_read_time()
79 	tm->tm_min = bcd2bin(tm->tm_min);  in m48t35_read_time()
80 	tm->tm_hour = bcd2bin(tm->tm_hour);  in m48t35_read_time()
81 	tm->tm_mday = bcd2bin(tm->tm_mday);  in m48t35_read_time()
82 	tm->tm_mon = bcd2bin(tm->tm_mon);  in m48t35_read_time()
83 	tm->tm_year = bcd2bin(tm->tm_year);  in m48t35_read_time()
89 	tm->tm_year += 70;  in m48t35_read_time()
90 	if (tm->tm_year <= 69)  in m48t35_read_time()
91 		tm->tm_year += 100;  in m48t35_read_time()
93 	tm->tm_mon--;  in m48t35_read_time()
104 	yrs = tm->tm_year + 1900;  in m48t35_set_time()
105 	mon = tm->tm_mon + 1;   /* tm_mon starts at zero */  in m48t35_set_time()
106 	day = tm->tm_mday;  in m48t35_set_time()
107 	hrs = tm->tm_hour;  in m48t35_set_time()
108 	min = tm->tm_min;  in m48t35_set_time()
109 	sec = tm->tm_sec;  in m48t35_set_time()
112 		return -EINVAL;  in m48t35_set_time()
114 	yrs -= 1970;  in m48t35_set_time()
116 		return -EINVAL;  in m48t35_set_time()
119 		return -EINVAL;  in m48t35_set_time()
122 		yrs -= 100;  in m48t35_set_time()
131 	spin_lock_irq(&priv->lock);  in m48t35_set_time()
132 	control = readb(&priv->reg->control);  in m48t35_set_time()
133 	writeb(control | M48T35_RTC_SET, &priv->reg->control);  in m48t35_set_time()
134 	writeb(yrs, &priv->reg->year);  in m48t35_set_time()
135 	writeb(mon, &priv->reg->month);  in m48t35_set_time()
136 	writeb(day, &priv->reg->date);  in m48t35_set_time()
137 	writeb(hrs, &priv->reg->hour);  in m48t35_set_time()
138 	writeb(min, &priv->reg->min);  in m48t35_set_time()
139 	writeb(sec, &priv->reg->sec);  in m48t35_set_time()
140 	writeb(control, &priv->reg->control);  in m48t35_set_time()
141 	spin_unlock_irq(&priv->lock);  in m48t35_set_time()
157 		return -ENODEV;  in m48t35_probe()
158 	priv = devm_kzalloc(&pdev->dev, sizeof(struct m48t35_priv), GFP_KERNEL);  in m48t35_probe()
160 		return -ENOMEM;  in m48t35_probe()
162 	priv->size = resource_size(res);  in m48t35_probe()
163 	if (!devm_request_mem_region(&pdev->dev, res->start, priv->size,  in m48t35_probe()
164 				     pdev->name))  in m48t35_probe()
165 		return -EBUSY;  in m48t35_probe()
167 	priv->baseaddr = res->start;  in m48t35_probe()
168 	priv->reg = devm_ioremap(&pdev->dev, priv->baseaddr, priv->size);  in m48t35_probe()
169 	if (!priv->reg)  in m48t35_probe()
170 		return -ENOMEM;  in m48t35_probe()
172 	spin_lock_init(&priv->lock);  in m48t35_probe()
176 	priv->rtc = devm_rtc_device_register(&pdev->dev, "m48t35",  in m48t35_probe()
178 	return PTR_ERR_OR_ZERO(priv->rtc);  in m48t35_probe()
183 		.name	= "rtc-m48t35",
193 MODULE_ALIAS("platform:rtc-m48t35");