1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* rtc-bq4802.c: TI BQ4802 RTC driver. |
3 | * |
4 | * Copyright (C) 2008 David S. Miller <davem@davemloft.net> |
5 | */ |
6 | |
7 | #include <linux/kernel.h> |
8 | #include <linux/module.h> |
9 | #include <linux/init.h> |
10 | #include <linux/io.h> |
11 | #include <linux/platform_device.h> |
12 | #include <linux/rtc.h> |
13 | #include <linux/bcd.h> |
14 | #include <linux/slab.h> |
15 | |
16 | MODULE_AUTHOR("David S. Miller <davem@davemloft.net>" ); |
17 | MODULE_DESCRIPTION("TI BQ4802 RTC driver" ); |
18 | MODULE_LICENSE("GPL" ); |
19 | |
20 | struct bq4802 { |
21 | void __iomem *regs; |
22 | unsigned long ioport; |
23 | struct rtc_device *rtc; |
24 | spinlock_t lock; |
25 | struct resource *r; |
26 | u8 (*read)(struct bq4802 *, int); |
27 | void (*write)(struct bq4802 *, int, u8); |
28 | }; |
29 | |
30 | static u8 bq4802_read_io(struct bq4802 *p, int off) |
31 | { |
32 | return inb(port: p->ioport + off); |
33 | } |
34 | |
35 | static void bq4802_write_io(struct bq4802 *p, int off, u8 val) |
36 | { |
37 | outb(value: val, port: p->ioport + off); |
38 | } |
39 | |
40 | static u8 bq4802_read_mem(struct bq4802 *p, int off) |
41 | { |
42 | return readb(addr: p->regs + off); |
43 | } |
44 | |
45 | static void bq4802_write_mem(struct bq4802 *p, int off, u8 val) |
46 | { |
47 | writeb(val, addr: p->regs + off); |
48 | } |
49 | |
50 | static int bq4802_read_time(struct device *dev, struct rtc_time *tm) |
51 | { |
52 | struct bq4802 *p = dev_get_drvdata(dev); |
53 | unsigned long flags; |
54 | unsigned int century; |
55 | u8 val; |
56 | |
57 | spin_lock_irqsave(&p->lock, flags); |
58 | |
59 | val = p->read(p, 0x0e); |
60 | p->write(p, 0xe, val | 0x08); |
61 | |
62 | tm->tm_sec = p->read(p, 0x00); |
63 | tm->tm_min = p->read(p, 0x02); |
64 | tm->tm_hour = p->read(p, 0x04); |
65 | tm->tm_mday = p->read(p, 0x06); |
66 | tm->tm_mon = p->read(p, 0x09); |
67 | tm->tm_year = p->read(p, 0x0a); |
68 | tm->tm_wday = p->read(p, 0x08); |
69 | century = p->read(p, 0x0f); |
70 | |
71 | p->write(p, 0x0e, val); |
72 | |
73 | spin_unlock_irqrestore(lock: &p->lock, flags); |
74 | |
75 | tm->tm_sec = bcd2bin(tm->tm_sec); |
76 | tm->tm_min = bcd2bin(tm->tm_min); |
77 | tm->tm_hour = bcd2bin(tm->tm_hour); |
78 | tm->tm_mday = bcd2bin(tm->tm_mday); |
79 | tm->tm_mon = bcd2bin(tm->tm_mon); |
80 | tm->tm_year = bcd2bin(tm->tm_year); |
81 | tm->tm_wday = bcd2bin(tm->tm_wday); |
82 | century = bcd2bin(century); |
83 | |
84 | tm->tm_year += (century * 100); |
85 | tm->tm_year -= 1900; |
86 | |
87 | tm->tm_mon--; |
88 | |
89 | return 0; |
90 | } |
91 | |
92 | static int bq4802_set_time(struct device *dev, struct rtc_time *tm) |
93 | { |
94 | struct bq4802 *p = dev_get_drvdata(dev); |
95 | u8 sec, min, hrs, day, mon, yrs, century, val; |
96 | unsigned long flags; |
97 | unsigned int year; |
98 | |
99 | year = tm->tm_year + 1900; |
100 | century = year / 100; |
101 | yrs = year % 100; |
102 | |
103 | mon = tm->tm_mon + 1; /* tm_mon starts at zero */ |
104 | day = tm->tm_mday; |
105 | hrs = tm->tm_hour; |
106 | min = tm->tm_min; |
107 | sec = tm->tm_sec; |
108 | |
109 | sec = bin2bcd(sec); |
110 | min = bin2bcd(min); |
111 | hrs = bin2bcd(hrs); |
112 | day = bin2bcd(day); |
113 | mon = bin2bcd(mon); |
114 | yrs = bin2bcd(yrs); |
115 | century = bin2bcd(century); |
116 | |
117 | spin_lock_irqsave(&p->lock, flags); |
118 | |
119 | val = p->read(p, 0x0e); |
120 | p->write(p, 0x0e, val | 0x08); |
121 | |
122 | p->write(p, 0x00, sec); |
123 | p->write(p, 0x02, min); |
124 | p->write(p, 0x04, hrs); |
125 | p->write(p, 0x06, day); |
126 | p->write(p, 0x09, mon); |
127 | p->write(p, 0x0a, yrs); |
128 | p->write(p, 0x0f, century); |
129 | |
130 | p->write(p, 0x0e, val); |
131 | |
132 | spin_unlock_irqrestore(lock: &p->lock, flags); |
133 | |
134 | return 0; |
135 | } |
136 | |
137 | static const struct rtc_class_ops bq4802_ops = { |
138 | .read_time = bq4802_read_time, |
139 | .set_time = bq4802_set_time, |
140 | }; |
141 | |
142 | static int bq4802_probe(struct platform_device *pdev) |
143 | { |
144 | struct bq4802 *p = devm_kzalloc(dev: &pdev->dev, size: sizeof(*p), GFP_KERNEL); |
145 | int err = -ENOMEM; |
146 | |
147 | if (!p) |
148 | goto out; |
149 | |
150 | spin_lock_init(&p->lock); |
151 | |
152 | p->r = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
153 | if (!p->r) { |
154 | p->r = platform_get_resource(pdev, IORESOURCE_IO, 0); |
155 | err = -EINVAL; |
156 | if (!p->r) |
157 | goto out; |
158 | } |
159 | if (p->r->flags & IORESOURCE_IO) { |
160 | p->ioport = p->r->start; |
161 | p->read = bq4802_read_io; |
162 | p->write = bq4802_write_io; |
163 | } else if (p->r->flags & IORESOURCE_MEM) { |
164 | p->regs = devm_ioremap(dev: &pdev->dev, offset: p->r->start, |
165 | size: resource_size(res: p->r)); |
166 | if (!p->regs){ |
167 | err = -ENOMEM; |
168 | goto out; |
169 | } |
170 | p->read = bq4802_read_mem; |
171 | p->write = bq4802_write_mem; |
172 | } else { |
173 | err = -EINVAL; |
174 | goto out; |
175 | } |
176 | |
177 | platform_set_drvdata(pdev, data: p); |
178 | |
179 | p->rtc = devm_rtc_device_register(dev: &pdev->dev, name: "bq4802" , |
180 | ops: &bq4802_ops, THIS_MODULE); |
181 | if (IS_ERR(ptr: p->rtc)) { |
182 | err = PTR_ERR(ptr: p->rtc); |
183 | goto out; |
184 | } |
185 | |
186 | err = 0; |
187 | out: |
188 | return err; |
189 | |
190 | } |
191 | |
192 | /* work with hotplug and coldplug */ |
193 | MODULE_ALIAS("platform:rtc-bq4802" ); |
194 | |
195 | static struct platform_driver bq4802_driver = { |
196 | .driver = { |
197 | .name = "rtc-bq4802" , |
198 | }, |
199 | .probe = bq4802_probe, |
200 | }; |
201 | |
202 | module_platform_driver(bq4802_driver); |
203 | |