From 1ae2f435350ec05224a39995c3a680aa6fdae5a5 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 23 Feb 2026 16:29:37 +0100 Subject: ACPI: x86: cmos_rtc: Create a CMOS RTC platform device Make the CMOS RTC ACPI scan handler create a platform device that will be used subsequently by rtc-cmos for driver binding on x86 systems with ACPI and update add_rtc_cmos() to skip registering a fallback platform device for the CMOS RTC when the above one has been registered. Signed-off-by: Rafael J. Wysocki Acked-by: Dave Hansen # x86 Link: https://patch.msgid.link/1962427.tdWV9SEqCh@rafael.j.wysocki --- include/linux/acpi.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include') diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 4d2f0bed7a06..2bdb801cee01 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -791,6 +791,8 @@ const char *acpi_get_subsystem_id(acpi_handle handle); int acpi_mrrm_max_mem_region(void); #endif +extern bool cmos_rtc_platform_device_present; + #else /* !CONFIG_ACPI */ #define acpi_disabled 1 @@ -1116,6 +1118,8 @@ static inline int acpi_mrrm_max_mem_region(void) return 1; } +#define cmos_rtc_platform_device_present false + #endif /* !CONFIG_ACPI */ #ifdef CONFIG_ACPI_HMAT -- cgit v1.2.3 From 2a78e42104444f948698f1225deaf515e9b7224d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 23 Feb 2026 16:30:21 +0100 Subject: ACPI: x86/rtc-cmos: Use platform device for driver binding Modify the rtc-cmos driver to bind to a platform device on systems with ACPI via acpi_match_table and advertise the CMOST RTC ACPI device IDs for driver auto-loading. Note that adding the requisite device IDs to it and exposing them via MODULE_DEVICE_TABLE() is sufficient for this purpose. Since the ACPI device IDs in question are the same as for the CMOS RTC ACPI scan handler, put them into a common header file and use the definition from there in both places. Additionally, to prevent a PNP device from being created for the CMOS RTC if a platform one is present already, make is_cmos_rtc_device() check cmos_rtc_platform_device_present introduced previously. Signed-off-by: Rafael J. Wysocki Acked-by: Alexandre Belloni Link: https://patch.msgid.link/13969123.uLZWGnKmhe@rafael.j.wysocki --- drivers/acpi/acpi_pnp.c | 2 +- drivers/acpi/x86/cmos_rtc.c | 5 +---- drivers/rtc/rtc-cmos.c | 10 ++++++++++ include/linux/acpi.h | 6 ++++++ 4 files changed, 18 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/drivers/acpi/acpi_pnp.c b/drivers/acpi/acpi_pnp.c index 85d9f78619a2..4ad8f56d1a5d 100644 --- a/drivers/acpi/acpi_pnp.c +++ b/drivers/acpi/acpi_pnp.c @@ -368,7 +368,7 @@ static int is_cmos_rtc_device(struct acpi_device *adev) { "PNP0B02" }, {""}, }; - return !acpi_match_device_ids(adev, ids); + return !cmos_rtc_platform_device_present && !acpi_match_device_ids(adev, ids); } bool acpi_is_pnp_device(struct acpi_device *adev) diff --git a/drivers/acpi/x86/cmos_rtc.c b/drivers/acpi/x86/cmos_rtc.c index bdd66dfd4a44..a6df5b991c96 100644 --- a/drivers/acpi/x86/cmos_rtc.c +++ b/drivers/acpi/x86/cmos_rtc.c @@ -18,10 +18,7 @@ #include "../internal.h" static const struct acpi_device_id acpi_cmos_rtc_ids[] = { - { "PNP0B00" }, - { "PNP0B01" }, - { "PNP0B02" }, - {} + ACPI_CMOS_RTC_IDS }; bool cmos_rtc_platform_device_present; diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c index 0743c6acd6e2..7457f42fd6f0 100644 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@ -27,6 +27,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include #include #include #include @@ -1476,6 +1477,14 @@ static __init void cmos_of_init(struct platform_device *pdev) #else static inline void cmos_of_init(struct platform_device *pdev) {} #endif + +#ifdef CONFIG_ACPI +static const struct acpi_device_id acpi_cmos_rtc_ids[] = { + ACPI_CMOS_RTC_IDS +}; +MODULE_DEVICE_TABLE(acpi, acpi_cmos_rtc_ids); +#endif + /*----------------------------------------------------------------*/ /* Platform setup should have set up an RTC device, when PNP is @@ -1530,6 +1539,7 @@ static struct platform_driver cmos_platform_driver = { .name = driver_name, .pm = &cmos_pm_ops, .of_match_table = of_match_ptr(of_cmos_match), + .acpi_match_table = ACPI_PTR(acpi_cmos_rtc_ids), } }; diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 2bdb801cee01..5ecdcdaf31aa 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -791,6 +791,12 @@ const char *acpi_get_subsystem_id(acpi_handle handle); int acpi_mrrm_max_mem_region(void); #endif +#define ACPI_CMOS_RTC_IDS \ + { "PNP0B00", }, \ + { "PNP0B01", }, \ + { "PNP0B02", }, \ + { "", } + extern bool cmos_rtc_platform_device_present; #else /* !CONFIG_ACPI */ -- cgit v1.2.3 From e8d1eb65193ce93283f8f56a069eee5d548a6b70 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 23 Feb 2026 16:33:27 +0100 Subject: ACPI: TAD/x86: cmos_rtc: Consolidate address space handler setup On x86, as a rule the CMOS RTC address space handler is set up by the CMOS RTC ACPI scan handler attach callback, acpi_cmos_rtc_attach(), but if the ACPI namespace does not contain a CMOS RTC device object, the CMOS RTC address space handler installation is taken care of the ACPI TAD (Timer and Alarm Device) driver. This is not particularly straightforward and can be avoided by adding the ACPI TAD device ID to the CMOS RTC ACPI scan handler which will cause it to create a platform device for ACPI TAD after installing the CMOS RTC address space handler. One related detail that needs to be taken care of, though, is that the creation of an ACPI TAD platform device should not cause cmos_rtc_platform_device_present to be set, since this may cause add_rtc_cmos() to suppress the creation of a fallback CMOS RTC platform device which may not be the right thing to do (for instance, due to the fact that the ACPI TAD driver is missing an RTC class device interface). After doing the above, the CMOS RTC address space handler installation and removal can be dropped from the ACPI TAD driver (which allows it to be simplified quite a bit), acpi_remove_cmos_rtc_space_handler() can be dropped and acpi_install_cmos_rtc_space_handler() can be made static. Update the code as per the above. Signed-off-by: Rafael J. Wysocki Link: https://patch.msgid.link/23028644.EfDdHjke4D@rafael.j.wysocki --- drivers/acpi/acpi_tad.c | 27 +++++---------------------- drivers/acpi/x86/cmos_rtc.c | 26 +++++--------------------- include/acpi/acpi_bus.h | 9 --------- 3 files changed, 10 insertions(+), 52 deletions(-) (limited to 'include') diff --git a/drivers/acpi/acpi_tad.c b/drivers/acpi/acpi_tad.c index 6d870d97ada6..4f5089fc023d 100644 --- a/drivers/acpi/acpi_tad.c +++ b/drivers/acpi/acpi_tad.c @@ -563,7 +563,6 @@ static int acpi_tad_disable_timer(struct device *dev, u32 timer_id) static void acpi_tad_remove(struct platform_device *pdev) { struct device *dev = &pdev->dev; - acpi_handle handle = ACPI_HANDLE(dev); struct acpi_tad_driver_data *dd = dev_get_drvdata(dev); device_init_wakeup(dev, false); @@ -587,7 +586,6 @@ static void acpi_tad_remove(struct platform_device *pdev) pm_runtime_suspend(dev); pm_runtime_disable(dev); - acpi_remove_cmos_rtc_space_handler(handle); } static int acpi_tad_probe(struct platform_device *pdev) @@ -599,11 +597,6 @@ static int acpi_tad_probe(struct platform_device *pdev) unsigned long long caps; int ret; - ret = acpi_install_cmos_rtc_space_handler(handle); - if (ret < 0) { - dev_info(dev, "Unable to install space handler\n"); - return -ENODEV; - } /* * Initialization failure messages are mostly about firmware issues, so * print them at the "info" level. @@ -611,27 +604,22 @@ static int acpi_tad_probe(struct platform_device *pdev) status = acpi_evaluate_integer(handle, "_GCP", NULL, &caps); if (ACPI_FAILURE(status)) { dev_info(dev, "Unable to get capabilities\n"); - ret = -ENODEV; - goto remove_handler; + return -ENODEV; } if (!(caps & ACPI_TAD_AC_WAKE)) { dev_info(dev, "Unsupported capabilities\n"); - ret = -ENODEV; - goto remove_handler; + return -ENODEV; } if (!acpi_has_method(handle, "_PRW")) { dev_info(dev, "Missing _PRW\n"); - ret = -ENODEV; - goto remove_handler; + return -ENODEV; } dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL); - if (!dd) { - ret = -ENOMEM; - goto remove_handler; - } + if (!dd) + return -ENOMEM; dd->capabilities = caps; dev_set_drvdata(dev, dd); @@ -673,11 +661,6 @@ static int acpi_tad_probe(struct platform_device *pdev) fail: acpi_tad_remove(pdev); - /* Don't fallthrough because cmos rtc space handler is removed in acpi_tad_remove() */ - return ret; - -remove_handler: - acpi_remove_cmos_rtc_space_handler(handle); return ret; } diff --git a/drivers/acpi/x86/cmos_rtc.c b/drivers/acpi/x86/cmos_rtc.c index a6df5b991c96..ced334e19896 100644 --- a/drivers/acpi/x86/cmos_rtc.c +++ b/drivers/acpi/x86/cmos_rtc.c @@ -18,13 +18,12 @@ #include "../internal.h" static const struct acpi_device_id acpi_cmos_rtc_ids[] = { + { "ACPI000E", 1 }, /* ACPI Time and Alarm Device (TAD) */ ACPI_CMOS_RTC_IDS }; bool cmos_rtc_platform_device_present; -static bool cmos_rtc_space_handler_present __read_mostly; - static acpi_status acpi_cmos_rtc_space_handler(u32 function, acpi_physical_address address, u32 bits, u64 *value64, @@ -56,8 +55,9 @@ static acpi_status acpi_cmos_rtc_space_handler(u32 function, return AE_BAD_PARAMETER; } -int acpi_install_cmos_rtc_space_handler(acpi_handle handle) +static int acpi_install_cmos_rtc_space_handler(acpi_handle handle) { + static bool cmos_rtc_space_handler_present __read_mostly; acpi_status status; if (cmos_rtc_space_handler_present) @@ -76,22 +76,6 @@ int acpi_install_cmos_rtc_space_handler(acpi_handle handle) return 1; } -EXPORT_SYMBOL_GPL(acpi_install_cmos_rtc_space_handler); - -void acpi_remove_cmos_rtc_space_handler(acpi_handle handle) -{ - acpi_status status; - - if (cmos_rtc_space_handler_present) - return; - - status = acpi_remove_address_space_handler(handle, - ACPI_ADR_SPACE_CMOS, - acpi_cmos_rtc_space_handler); - if (ACPI_FAILURE(status)) - pr_err("Failed to remove CMOS-RTC address space handler\n"); -} -EXPORT_SYMBOL_GPL(acpi_remove_cmos_rtc_space_handler); static int acpi_cmos_rtc_attach(struct acpi_device *adev, const struct acpi_device_id *id) @@ -103,9 +87,9 @@ static int acpi_cmos_rtc_attach(struct acpi_device *adev, return ret; if (IS_ERR_OR_NULL(acpi_create_platform_device(adev, NULL))) { - pr_err("Failed to create CMOS-RTC platform device\n"); + pr_err("Failed to create a platform device for %s\n", (char *)id->id); return 0; - } else { + } else if (!id->driver_data) { cmos_rtc_platform_device_present = true; } return 1; diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index aad1a95e6863..be6d9032a161 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -760,8 +760,6 @@ int acpi_disable_wakeup_device_power(struct acpi_device *dev); #ifdef CONFIG_X86 bool acpi_device_override_status(struct acpi_device *adev, unsigned long long *status); bool acpi_quirk_skip_acpi_ac_and_battery(void); -int acpi_install_cmos_rtc_space_handler(acpi_handle handle); -void acpi_remove_cmos_rtc_space_handler(acpi_handle handle); int acpi_quirk_skip_serdev_enumeration(struct device *controller_parent, bool *skip); #else static inline bool acpi_device_override_status(struct acpi_device *adev, @@ -773,13 +771,6 @@ static inline bool acpi_quirk_skip_acpi_ac_and_battery(void) { return false; } -static inline int acpi_install_cmos_rtc_space_handler(acpi_handle handle) -{ - return 1; -} -static inline void acpi_remove_cmos_rtc_space_handler(acpi_handle handle) -{ -} static inline int acpi_quirk_skip_serdev_enumeration(struct device *controller_parent, bool *skip) { -- cgit v1.2.3