1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * linux/drivers/rtc/rtc-pl030.c |
4 | * |
5 | * Copyright (C) 2000-2001 Deep Blue Solutions Ltd. |
6 | */ |
7 | #include <linux/module.h> |
8 | #include <linux/rtc.h> |
9 | #include <linux/init.h> |
10 | #include <linux/interrupt.h> |
11 | #include <linux/amba/bus.h> |
12 | #include <linux/io.h> |
13 | #include <linux/slab.h> |
14 | |
15 | #define RTC_DR (0) |
16 | #define RTC_MR (4) |
17 | #define RTC_STAT (8) |
18 | #define RTC_EOI (8) |
19 | #define RTC_LR (12) |
20 | #define RTC_CR (16) |
21 | #define RTC_CR_MIE (1 << 0) |
22 | |
23 | struct pl030_rtc { |
24 | struct rtc_device *rtc; |
25 | void __iomem *base; |
26 | }; |
27 | |
28 | static irqreturn_t pl030_interrupt(int irq, void *dev_id) |
29 | { |
30 | struct pl030_rtc *rtc = dev_id; |
31 | writel(val: 0, addr: rtc->base + RTC_EOI); |
32 | return IRQ_HANDLED; |
33 | } |
34 | |
35 | static int pl030_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) |
36 | { |
37 | struct pl030_rtc *rtc = dev_get_drvdata(dev); |
38 | |
39 | rtc_time64_to_tm(readl(addr: rtc->base + RTC_MR), tm: &alrm->time); |
40 | return 0; |
41 | } |
42 | |
43 | static int pl030_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) |
44 | { |
45 | struct pl030_rtc *rtc = dev_get_drvdata(dev); |
46 | |
47 | writel(val: rtc_tm_to_time64(tm: &alrm->time), addr: rtc->base + RTC_MR); |
48 | |
49 | return 0; |
50 | } |
51 | |
52 | static int pl030_read_time(struct device *dev, struct rtc_time *tm) |
53 | { |
54 | struct pl030_rtc *rtc = dev_get_drvdata(dev); |
55 | |
56 | rtc_time64_to_tm(readl(addr: rtc->base + RTC_DR), tm); |
57 | |
58 | return 0; |
59 | } |
60 | |
61 | /* |
62 | * Set the RTC time. Unfortunately, we can't accurately set |
63 | * the point at which the counter updates. |
64 | * |
65 | * Also, since RTC_LR is transferred to RTC_CR on next rising |
66 | * edge of the 1Hz clock, we must write the time one second |
67 | * in advance. |
68 | */ |
69 | static int pl030_set_time(struct device *dev, struct rtc_time *tm) |
70 | { |
71 | struct pl030_rtc *rtc = dev_get_drvdata(dev); |
72 | |
73 | writel(val: rtc_tm_to_time64(tm) + 1, addr: rtc->base + RTC_LR); |
74 | |
75 | return 0; |
76 | } |
77 | |
78 | static const struct rtc_class_ops pl030_ops = { |
79 | .read_time = pl030_read_time, |
80 | .set_time = pl030_set_time, |
81 | .read_alarm = pl030_read_alarm, |
82 | .set_alarm = pl030_set_alarm, |
83 | }; |
84 | |
85 | static int pl030_probe(struct amba_device *dev, const struct amba_id *id) |
86 | { |
87 | struct pl030_rtc *rtc; |
88 | int ret; |
89 | |
90 | ret = amba_request_regions(dev, NULL); |
91 | if (ret) |
92 | goto err_req; |
93 | |
94 | rtc = devm_kzalloc(dev: &dev->dev, size: sizeof(*rtc), GFP_KERNEL); |
95 | if (!rtc) { |
96 | ret = -ENOMEM; |
97 | goto err_rtc; |
98 | } |
99 | |
100 | rtc->rtc = devm_rtc_allocate_device(dev: &dev->dev); |
101 | if (IS_ERR(ptr: rtc->rtc)) { |
102 | ret = PTR_ERR(ptr: rtc->rtc); |
103 | goto err_rtc; |
104 | } |
105 | |
106 | rtc->rtc->ops = &pl030_ops; |
107 | rtc->rtc->range_max = U32_MAX; |
108 | rtc->base = ioremap(offset: dev->res.start, size: resource_size(res: &dev->res)); |
109 | if (!rtc->base) { |
110 | ret = -ENOMEM; |
111 | goto err_rtc; |
112 | } |
113 | |
114 | __raw_writel(val: 0, addr: rtc->base + RTC_CR); |
115 | __raw_writel(val: 0, addr: rtc->base + RTC_EOI); |
116 | |
117 | amba_set_drvdata(dev, rtc); |
118 | |
119 | ret = request_irq(irq: dev->irq[0], handler: pl030_interrupt, flags: 0, |
120 | name: "rtc-pl030" , dev: rtc); |
121 | if (ret) |
122 | goto err_irq; |
123 | |
124 | ret = devm_rtc_register_device(rtc->rtc); |
125 | if (ret) |
126 | goto err_reg; |
127 | |
128 | return 0; |
129 | |
130 | err_reg: |
131 | free_irq(dev->irq[0], rtc); |
132 | err_irq: |
133 | iounmap(addr: rtc->base); |
134 | err_rtc: |
135 | amba_release_regions(dev); |
136 | err_req: |
137 | return ret; |
138 | } |
139 | |
140 | static void pl030_remove(struct amba_device *dev) |
141 | { |
142 | struct pl030_rtc *rtc = amba_get_drvdata(dev); |
143 | |
144 | writel(val: 0, addr: rtc->base + RTC_CR); |
145 | |
146 | free_irq(dev->irq[0], rtc); |
147 | iounmap(addr: rtc->base); |
148 | amba_release_regions(dev); |
149 | } |
150 | |
151 | static struct amba_id pl030_ids[] = { |
152 | { |
153 | .id = 0x00041030, |
154 | .mask = 0x000fffff, |
155 | }, |
156 | { 0, 0 }, |
157 | }; |
158 | |
159 | MODULE_DEVICE_TABLE(amba, pl030_ids); |
160 | |
161 | static struct amba_driver pl030_driver = { |
162 | .drv = { |
163 | .name = "rtc-pl030" , |
164 | }, |
165 | .probe = pl030_probe, |
166 | .remove = pl030_remove, |
167 | .id_table = pl030_ids, |
168 | }; |
169 | |
170 | module_amba_driver(pl030_driver); |
171 | |
172 | MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>" ); |
173 | MODULE_DESCRIPTION("ARM AMBA PL030 RTC Driver" ); |
174 | MODULE_LICENSE("GPL" ); |
175 | |