1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2008
4 * Gururaja Hebbar gururajakr@sanyo.co.in
5 *
6 * reference linux-2.6.20.6/drivers/rtc/rtc-pl031.c
7 */
8
9 #include <common.h>
10 #include <command.h>
11 #include <dm.h>
12 #include <errno.h>
13 #include <log.h>
14 #include <rtc.h>
15 #include <asm/io.h>
16 #include <asm/types.h>
17
18 /*
19 * Register definitions
20 */
21 #define RTC_DR 0x00 /* Data read register */
22 #define RTC_MR 0x04 /* Match register */
23 #define RTC_LR 0x08 /* Data load register */
24 #define RTC_CR 0x0c /* Control register */
25 #define RTC_IMSC 0x10 /* Interrupt mask and set register */
26 #define RTC_RIS 0x14 /* Raw interrupt status register */
27 #define RTC_MIS 0x18 /* Masked interrupt status register */
28 #define RTC_ICR 0x1c /* Interrupt clear register */
29
30 #define RTC_CR_START (1 << 0)
31
32 struct pl031_plat {
33 phys_addr_t base;
34 };
35
pl031_read_reg(struct udevice * dev,int reg)36 static inline u32 pl031_read_reg(struct udevice *dev, int reg)
37 {
38 struct pl031_plat *pdata = dev_get_plat(dev);
39
40 return readl(pdata->base + reg);
41 }
42
pl031_write_reg(struct udevice * dev,int reg,u32 value)43 static inline u32 pl031_write_reg(struct udevice *dev, int reg, u32 value)
44 {
45 struct pl031_plat *pdata = dev_get_plat(dev);
46
47 return writel(value, pdata->base + reg);
48 }
49
50 /*
51 * Probe RTC device
52 */
pl031_probe(struct udevice * dev)53 static int pl031_probe(struct udevice *dev)
54 {
55 /* Enable RTC Start in Control register*/
56 pl031_write_reg(dev, RTC_CR, RTC_CR_START);
57
58 return 0;
59 }
60
61 /*
62 * Get the current time from the RTC
63 */
pl031_get(struct udevice * dev,struct rtc_time * tm)64 static int pl031_get(struct udevice *dev, struct rtc_time *tm)
65 {
66 unsigned long tim;
67
68 if (!tm)
69 return -EINVAL;
70
71 tim = pl031_read_reg(dev, RTC_DR);
72
73 rtc_to_tm(tim, tm);
74
75 debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
76 tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
77 tm->tm_hour, tm->tm_min, tm->tm_sec);
78
79 return 0;
80 }
81
82 /*
83 * Set the RTC
84 */
pl031_set(struct udevice * dev,const struct rtc_time * tm)85 static int pl031_set(struct udevice *dev, const struct rtc_time *tm)
86 {
87 unsigned long tim;
88
89 if (!tm)
90 return -EINVAL;
91
92 debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
93 tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
94 tm->tm_hour, tm->tm_min, tm->tm_sec);
95
96 /* Calculate number of seconds this incoming time represents */
97 tim = rtc_mktime(tm);
98
99 pl031_write_reg(dev, RTC_LR, tim);
100
101 return 0;
102 }
103
104 /*
105 * Reset the RTC. We set the date back to 1970-01-01.
106 */
pl031_reset(struct udevice * dev)107 static int pl031_reset(struct udevice *dev)
108 {
109 pl031_write_reg(dev, RTC_LR, 0);
110
111 return 0;
112 }
113
114 static const struct rtc_ops pl031_ops = {
115 .get = pl031_get,
116 .set = pl031_set,
117 .reset = pl031_reset,
118 };
119
120 static const struct udevice_id pl031_ids[] = {
121 { .compatible = "arm,pl031" },
122 { }
123 };
124
pl031_of_to_plat(struct udevice * dev)125 static int pl031_of_to_plat(struct udevice *dev)
126 {
127 struct pl031_plat *pdata = dev_get_plat(dev);
128
129 pdata->base = dev_read_addr(dev);
130
131 return 0;
132 }
133
134 U_BOOT_DRIVER(rtc_pl031) = {
135 .name = "rtc-pl031",
136 .id = UCLASS_RTC,
137 .of_match = pl031_ids,
138 .probe = pl031_probe,
139 .of_to_plat = pl031_of_to_plat,
140 .plat_auto = sizeof(struct pl031_plat),
141 .ops = &pl031_ops,
142 };
143