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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/rtc/rtc-cros-ec.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/rtc/rtc-cros-ec.c')
| -rw-r--r-- | drivers/rtc/rtc-cros-ec.c | 409 |
1 files changed, 409 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-cros-ec.c b/drivers/rtc/rtc-cros-ec.c new file mode 100644 index 000000000..f56650899 --- /dev/null +++ b/drivers/rtc/rtc-cros-ec.c @@ -0,0 +1,409 @@ +// SPDX-License-Identifier: GPL-2.0 +// RTC driver for ChromeOS Embedded Controller. +// +// Copyright (C) 2017 Google, Inc. +// Author: Stephen Barber <smbarber@chromium.org> + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_data/cros_ec_commands.h> +#include <linux/platform_data/cros_ec_proto.h> +#include <linux/platform_device.h> +#include <linux/rtc.h> +#include <linux/slab.h> + +#define DRV_NAME "cros-ec-rtc" + +#define SECS_PER_DAY (24 * 60 * 60) + +/** + * struct cros_ec_rtc - Driver data for EC RTC + * + * @cros_ec: Pointer to EC device + * @rtc: Pointer to RTC device + * @notifier: Notifier info for responding to EC events + * @saved_alarm: Alarm to restore when interrupts are reenabled + */ +struct cros_ec_rtc { + struct cros_ec_device *cros_ec; + struct rtc_device *rtc; + struct notifier_block notifier; + u32 saved_alarm; +}; + +static int cros_ec_rtc_get(struct cros_ec_device *cros_ec, u32 command, + u32 *response) +{ + DEFINE_RAW_FLEX(struct cros_ec_command, msg, data, + sizeof(struct ec_response_rtc)); + int ret; + + msg->command = command; + msg->insize = sizeof(struct ec_response_rtc); + + ret = cros_ec_cmd_xfer_status(cros_ec, msg); + if (ret < 0) + return ret; + + *response = ((struct ec_response_rtc *)msg->data)->time; + + return 0; +} + +static int cros_ec_rtc_set(struct cros_ec_device *cros_ec, u32 command, + u32 param) +{ + DEFINE_RAW_FLEX(struct cros_ec_command, msg, data, + sizeof(struct ec_response_rtc)); + int ret; + + msg->command = command; + msg->outsize = sizeof(struct ec_response_rtc); + ((struct ec_response_rtc *)msg->data)->time = param; + + ret = cros_ec_cmd_xfer_status(cros_ec, msg); + if (ret < 0) + return ret; + return 0; +} + +/* Read the current time from the EC. */ +static int cros_ec_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct cros_ec_rtc *cros_ec_rtc = dev_get_drvdata(dev); + struct cros_ec_device *cros_ec = cros_ec_rtc->cros_ec; + int ret; + u32 time; + + ret = cros_ec_rtc_get(cros_ec, EC_CMD_RTC_GET_VALUE, &time); + if (ret) { + dev_err(dev, "error getting time: %d\n", ret); + return ret; + } + + rtc_time64_to_tm(time, tm); + + return 0; +} + +/* Set the current EC time. */ +static int cros_ec_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct cros_ec_rtc *cros_ec_rtc = dev_get_drvdata(dev); + struct cros_ec_device *cros_ec = cros_ec_rtc->cros_ec; + int ret; + time64_t time = rtc_tm_to_time64(tm); + + ret = cros_ec_rtc_set(cros_ec, EC_CMD_RTC_SET_VALUE, (u32)time); + if (ret < 0) { + dev_err(dev, "error setting time: %d\n", ret); + return ret; + } + + return 0; +} + +/* Read alarm time from RTC. */ +static int cros_ec_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct cros_ec_rtc *cros_ec_rtc = dev_get_drvdata(dev); + struct cros_ec_device *cros_ec = cros_ec_rtc->cros_ec; + int ret; + u32 current_time, alarm_offset; + + /* + * The EC host command for getting the alarm is relative (i.e. 5 + * seconds from now) whereas rtc_wkalrm is absolute. Get the current + * RTC time first so we can calculate the relative time. + */ + ret = cros_ec_rtc_get(cros_ec, EC_CMD_RTC_GET_VALUE, ¤t_time); + if (ret < 0) { + dev_err(dev, "error getting time: %d\n", ret); + return ret; + } + + ret = cros_ec_rtc_get(cros_ec, EC_CMD_RTC_GET_ALARM, &alarm_offset); + if (ret < 0) { + dev_err(dev, "error getting alarm: %d\n", ret); + return ret; + } + + rtc_time64_to_tm(current_time + alarm_offset, &alrm->time); + + return 0; +} + +/* Set the EC's RTC alarm. */ +static int cros_ec_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct cros_ec_rtc *cros_ec_rtc = dev_get_drvdata(dev); + struct cros_ec_device *cros_ec = cros_ec_rtc->cros_ec; + int ret; + time64_t alarm_time; + u32 current_time, alarm_offset; + + /* + * The EC host command for setting the alarm is relative + * (i.e. 5 seconds from now) whereas rtc_wkalrm is absolute. + * Get the current RTC time first so we can calculate the + * relative time. + */ + ret = cros_ec_rtc_get(cros_ec, EC_CMD_RTC_GET_VALUE, ¤t_time); + if (ret < 0) { + dev_err(dev, "error getting time: %d\n", ret); + return ret; + } + + alarm_time = rtc_tm_to_time64(&alrm->time); + + if (alarm_time < 0 || alarm_time > U32_MAX) + return -EINVAL; + + if (!alrm->enabled) { + /* + * If the alarm is being disabled, send an alarm + * clear command. + */ + alarm_offset = EC_RTC_ALARM_CLEAR; + cros_ec_rtc->saved_alarm = (u32)alarm_time; + } else { + /* Don't set an alarm in the past. */ + if ((u32)alarm_time <= current_time) + return -ETIME; + + alarm_offset = (u32)alarm_time - current_time; + } + + ret = cros_ec_rtc_set(cros_ec, EC_CMD_RTC_SET_ALARM, alarm_offset); + if (ret < 0) { + dev_err(dev, "error setting alarm in %u seconds: %d\n", + alarm_offset, ret); + /* + * The EC code returns -EINVAL if the alarm time is too + * far in the future. Convert it to the expected error code. + */ + if (ret == -EINVAL) + ret = -ERANGE; + return ret; + } + + return 0; +} + +static int cros_ec_rtc_alarm_irq_enable(struct device *dev, + unsigned int enabled) +{ + struct cros_ec_rtc *cros_ec_rtc = dev_get_drvdata(dev); + struct cros_ec_device *cros_ec = cros_ec_rtc->cros_ec; + int ret; + u32 current_time, alarm_offset, alarm_value; + + ret = cros_ec_rtc_get(cros_ec, EC_CMD_RTC_GET_VALUE, ¤t_time); + if (ret < 0) { + dev_err(dev, "error getting time: %d\n", ret); + return ret; + } + + if (enabled) { + /* Restore saved alarm if it's still in the future. */ + if (cros_ec_rtc->saved_alarm < current_time) + alarm_offset = EC_RTC_ALARM_CLEAR; + else + alarm_offset = cros_ec_rtc->saved_alarm - current_time; + + ret = cros_ec_rtc_set(cros_ec, EC_CMD_RTC_SET_ALARM, + alarm_offset); + if (ret < 0) { + dev_err(dev, "error restoring alarm: %d\n", ret); + return ret; + } + } else { + /* Disable alarm, saving the old alarm value. */ + ret = cros_ec_rtc_get(cros_ec, EC_CMD_RTC_GET_ALARM, + &alarm_offset); + if (ret < 0) { + dev_err(dev, "error saving alarm: %d\n", ret); + return ret; + } + + alarm_value = current_time + alarm_offset; + + /* + * If the current EC alarm is already past, we don't want + * to set an alarm when we go through the alarm irq enable + * path. + */ + if (alarm_value < current_time) + cros_ec_rtc->saved_alarm = EC_RTC_ALARM_CLEAR; + else + cros_ec_rtc->saved_alarm = alarm_value; + + alarm_offset = EC_RTC_ALARM_CLEAR; + ret = cros_ec_rtc_set(cros_ec, EC_CMD_RTC_SET_ALARM, + alarm_offset); + if (ret < 0) { + dev_err(dev, "error disabling alarm: %d\n", ret); + return ret; + } + } + + return 0; +} + +static int cros_ec_rtc_event(struct notifier_block *nb, + unsigned long queued_during_suspend, + void *_notify) +{ + struct cros_ec_rtc *cros_ec_rtc; + struct rtc_device *rtc; + struct cros_ec_device *cros_ec; + u32 host_event; + + cros_ec_rtc = container_of(nb, struct cros_ec_rtc, notifier); + rtc = cros_ec_rtc->rtc; + cros_ec = cros_ec_rtc->cros_ec; + + host_event = cros_ec_get_host_event(cros_ec); + if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_RTC)) { + rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF); + return NOTIFY_OK; + } else { + return NOTIFY_DONE; + } +} + +static const struct rtc_class_ops cros_ec_rtc_ops = { + .read_time = cros_ec_rtc_read_time, + .set_time = cros_ec_rtc_set_time, + .read_alarm = cros_ec_rtc_read_alarm, + .set_alarm = cros_ec_rtc_set_alarm, + .alarm_irq_enable = cros_ec_rtc_alarm_irq_enable, +}; + +#ifdef CONFIG_PM_SLEEP +static int cros_ec_rtc_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct cros_ec_rtc *cros_ec_rtc = dev_get_drvdata(&pdev->dev); + + if (device_may_wakeup(dev)) + return enable_irq_wake(cros_ec_rtc->cros_ec->irq); + + return 0; +} + +static int cros_ec_rtc_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct cros_ec_rtc *cros_ec_rtc = dev_get_drvdata(&pdev->dev); + + if (device_may_wakeup(dev)) + return disable_irq_wake(cros_ec_rtc->cros_ec->irq); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(cros_ec_rtc_pm_ops, cros_ec_rtc_suspend, + cros_ec_rtc_resume); + +static int cros_ec_rtc_probe(struct platform_device *pdev) +{ + struct cros_ec_dev *ec_dev = dev_get_drvdata(pdev->dev.parent); + struct cros_ec_device *cros_ec = ec_dev->ec_dev; + struct cros_ec_rtc *cros_ec_rtc; + struct rtc_time tm; + int ret; + + cros_ec_rtc = devm_kzalloc(&pdev->dev, sizeof(*cros_ec_rtc), + GFP_KERNEL); + if (!cros_ec_rtc) + return -ENOMEM; + + platform_set_drvdata(pdev, cros_ec_rtc); + cros_ec_rtc->cros_ec = cros_ec; + + /* Get initial time */ + ret = cros_ec_rtc_read_time(&pdev->dev, &tm); + if (ret) { + dev_err(&pdev->dev, "failed to read RTC time\n"); + return ret; + } + + ret = device_init_wakeup(&pdev->dev, true); + if (ret) { + dev_err(&pdev->dev, "failed to initialize wakeup\n"); + return ret; + } + + cros_ec_rtc->rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(cros_ec_rtc->rtc)) + return PTR_ERR(cros_ec_rtc->rtc); + + cros_ec_rtc->rtc->ops = &cros_ec_rtc_ops; + cros_ec_rtc->rtc->range_max = U32_MAX; + + /* + * The RTC on some older Chromebooks can only handle alarms less than + * 24 hours in the future. The only way to find out is to try to set an + * alarm further in the future. If that fails, assume that the RTC + * connected to the EC can only handle less than 24 hours of alarm + * window. + */ + ret = cros_ec_rtc_set(cros_ec, EC_CMD_RTC_SET_ALARM, SECS_PER_DAY * 2); + if (ret == -EINVAL) + cros_ec_rtc->rtc->alarm_offset_max = SECS_PER_DAY - 1; + + (void)cros_ec_rtc_set(cros_ec, EC_CMD_RTC_SET_ALARM, + EC_RTC_ALARM_CLEAR); + + ret = devm_rtc_register_device(cros_ec_rtc->rtc); + if (ret) + return ret; + + /* Get RTC events from the EC. */ + cros_ec_rtc->notifier.notifier_call = cros_ec_rtc_event; + ret = blocking_notifier_chain_register(&cros_ec->event_notifier, + &cros_ec_rtc->notifier); + if (ret) { + dev_err(&pdev->dev, "failed to register notifier\n"); + return ret; + } + + return 0; +} + +static void cros_ec_rtc_remove(struct platform_device *pdev) +{ + struct cros_ec_rtc *cros_ec_rtc = platform_get_drvdata(pdev); + struct device *dev = &pdev->dev; + int ret; + + ret = blocking_notifier_chain_unregister( + &cros_ec_rtc->cros_ec->event_notifier, + &cros_ec_rtc->notifier); + if (ret) + dev_err(dev, "failed to unregister notifier\n"); +} + +static const struct platform_device_id cros_ec_rtc_id[] = { + { .name = DRV_NAME }, + { } +}; +MODULE_DEVICE_TABLE(platform, cros_ec_rtc_id); + +static struct platform_driver cros_ec_rtc_driver = { + .probe = cros_ec_rtc_probe, + .remove = cros_ec_rtc_remove, + .driver = { + .name = DRV_NAME, + .pm = &cros_ec_rtc_pm_ops, + }, + .id_table = cros_ec_rtc_id, +}; + +module_platform_driver(cros_ec_rtc_driver); + +MODULE_DESCRIPTION("RTC driver for Chrome OS ECs"); +MODULE_AUTHOR("Stephen Barber <smbarber@chromium.org>"); +MODULE_LICENSE("GPL v2"); |
