Heinrich Schuchardt | 04ded00 | 2020-10-22 23:52:14 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
| 2 | /* |
| 3 | * Copyright 2020, Heinrich Schuchardt <xypron.glpk@gmx.de> |
| 4 | * |
| 5 | * This driver emulates a real time clock based on timer ticks. |
| 6 | */ |
| 7 | |
Heinrich Schuchardt | 04ded00 | 2020-10-22 23:52:14 +0200 | [diff] [blame] | 8 | #include <div64.h> |
| 9 | #include <dm.h> |
Heinrich Schuchardt | a41437e | 2020-10-30 03:27:22 +0100 | [diff] [blame] | 10 | #include <env.h> |
Heinrich Schuchardt | 04ded00 | 2020-10-22 23:52:14 +0200 | [diff] [blame] | 11 | #include <rtc.h> |
Tom Rini | af20c8a | 2024-05-01 19:31:15 -0600 | [diff] [blame] | 12 | #include <time.h> |
Pali Rohár | 6e1f085 | 2021-08-02 15:18:38 +0200 | [diff] [blame] | 13 | #include <timestamp.h> |
Heinrich Schuchardt | 04ded00 | 2020-10-22 23:52:14 +0200 | [diff] [blame] | 14 | |
| 15 | /** |
| 16 | * struct emul_rtc - private data for emulated RTC driver |
| 17 | */ |
| 18 | struct emul_rtc { |
| 19 | /** |
| 20 | * @offset_us: microseconds from 1970-01-01 to timer_get_us() base |
| 21 | */ |
| 22 | u64 offset_us; |
| 23 | /** |
| 24 | * @isdst: daylight saving time |
| 25 | */ |
| 26 | int isdst; |
| 27 | }; |
| 28 | |
| 29 | static int emul_rtc_get(struct udevice *dev, struct rtc_time *time) |
| 30 | { |
| 31 | struct emul_rtc *priv = dev_get_priv(dev); |
| 32 | u64 now; |
| 33 | |
Heinrich Schuchardt | 04ded00 | 2020-10-22 23:52:14 +0200 | [diff] [blame] | 34 | now = timer_get_us() + priv->offset_us; |
| 35 | do_div(now, 1000000); |
| 36 | rtc_to_tm(now, time); |
| 37 | time->tm_isdst = priv->isdst; |
| 38 | |
| 39 | return 0; |
| 40 | } |
| 41 | |
| 42 | static int emul_rtc_set(struct udevice *dev, const struct rtc_time *time) |
| 43 | { |
| 44 | struct emul_rtc *priv = dev_get_priv(dev); |
| 45 | |
| 46 | if (time->tm_year < 1970) |
| 47 | return -EINVAL; |
| 48 | |
| 49 | priv->offset_us = rtc_mktime(time) * 1000000ULL - timer_get_us(); |
| 50 | |
| 51 | if (time->tm_isdst > 0) |
| 52 | priv->isdst = 1; |
| 53 | else if (time->tm_isdst < 0) |
| 54 | priv->isdst = -1; |
| 55 | else |
| 56 | priv->isdst = 0; |
| 57 | |
| 58 | return 0; |
| 59 | } |
| 60 | |
Heinrich Schuchardt | 05b06d7 | 2020-10-30 03:05:47 +0100 | [diff] [blame] | 61 | int emul_rtc_probe(struct udevice *dev) |
| 62 | { |
| 63 | struct emul_rtc *priv = dev_get_priv(dev); |
Heinrich Schuchardt | a41437e | 2020-10-30 03:27:22 +0100 | [diff] [blame] | 64 | const char *epoch_str; |
| 65 | u64 epoch; |
| 66 | |
| 67 | epoch_str = env_get("rtc_emul_epoch"); |
Heinrich Schuchardt | 05b06d7 | 2020-10-30 03:05:47 +0100 | [diff] [blame] | 68 | |
Heinrich Schuchardt | a41437e | 2020-10-30 03:27:22 +0100 | [diff] [blame] | 69 | if (epoch_str) { |
| 70 | epoch = simple_strtoull(epoch_str, NULL, 10); |
| 71 | } else { |
| 72 | /* Use the build date as initial time */ |
| 73 | epoch = U_BOOT_EPOCH; |
| 74 | } |
| 75 | priv->offset_us = epoch * 1000000ULL - timer_get_us(); |
Heinrich Schuchardt | 05b06d7 | 2020-10-30 03:05:47 +0100 | [diff] [blame] | 76 | priv->isdst = -1; |
| 77 | |
| 78 | return 0; |
| 79 | } |
| 80 | |
Heinrich Schuchardt | 04ded00 | 2020-10-22 23:52:14 +0200 | [diff] [blame] | 81 | static const struct rtc_ops emul_rtc_ops = { |
| 82 | .get = emul_rtc_get, |
| 83 | .set = emul_rtc_set, |
| 84 | }; |
| 85 | |
| 86 | U_BOOT_DRIVER(rtc_emul) = { |
| 87 | .name = "rtc_emul", |
| 88 | .id = UCLASS_RTC, |
| 89 | .ops = &emul_rtc_ops, |
Heinrich Schuchardt | 05b06d7 | 2020-10-30 03:05:47 +0100 | [diff] [blame] | 90 | .probe = emul_rtc_probe, |
Simon Glass | 8a2b47f | 2020-12-03 16:55:17 -0700 | [diff] [blame] | 91 | .priv_auto = sizeof(struct emul_rtc), |
Heinrich Schuchardt | 04ded00 | 2020-10-22 23:52:14 +0200 | [diff] [blame] | 92 | }; |
| 93 | |
Simon Glass | 1d8364a | 2020-12-28 20:34:54 -0700 | [diff] [blame] | 94 | U_BOOT_DRVINFO(rtc_emul) = { |
Heinrich Schuchardt | 04ded00 | 2020-10-22 23:52:14 +0200 | [diff] [blame] | 95 | .name = "rtc_emul", |
| 96 | }; |