From 5c82a6ae0242416cfead597bb2b42aa3481a0ba7 Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Fri, 2 Jun 2017 14:15:15 +0200 Subject: rtc: remove rtc_device.name rtc->name is only used in messages were it is superfluous. Remove it completely from the structure. Signed-off-by: Alexandre Belloni --- include/linux/rtc.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include') diff --git a/include/linux/rtc.h b/include/linux/rtc.h index b693adac853b..d354f56e0cf5 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -116,7 +116,6 @@ struct rtc_device { struct module *owner; int id; - char name[RTC_DEVICE_NAME_SIZE]; const struct rtc_class_ops *ops; struct mutex ops_lock; -- cgit v1.2.3-71-gd317 From 3068a254d5519cd5116f61297462da6d1aa84c20 Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Thu, 6 Jul 2017 11:42:00 +0200 Subject: rtc: introduce new registration method Introduce rtc_register_device() to register an already allocated and initialized struct rtc_device. It automatically sets up the owner and the two steps allocation/registration will allow to remove race conditions in the IRQ handling of some driver. It also allows to properly extend the core without adding more arguments to rtc_device_register(). Signed-off-by: Alexandre Belloni --- drivers/rtc/class.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/rtc.h | 7 +++++ 2 files changed, 91 insertions(+) (limited to 'include') diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index 93ce88e1b1cb..58e2a05765bb 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -150,6 +150,7 @@ static SIMPLE_DEV_PM_OPS(rtc_class_dev_pm_ops, rtc_suspend, rtc_resume); #define RTC_CLASS_DEV_PM_OPS NULL #endif +/* Ensure the caller will set the id before releasing the device */ static struct rtc_device *rtc_allocate_device(void) { struct rtc_device *rtc; @@ -372,6 +373,89 @@ void devm_rtc_device_unregister(struct device *dev, struct rtc_device *rtc) } EXPORT_SYMBOL_GPL(devm_rtc_device_unregister); +static void devm_rtc_release_device(struct device *dev, void *res) +{ + struct rtc_device *rtc = *(struct rtc_device **)res; + + if (rtc->registered) + rtc_device_unregister(rtc); + else + put_device(&rtc->dev); +} + +struct rtc_device *devm_rtc_allocate_device(struct device *dev) +{ + struct rtc_device **ptr, *rtc; + int id, err; + + id = rtc_device_get_id(dev); + if (id < 0) + return ERR_PTR(id); + + ptr = devres_alloc(devm_rtc_release_device, sizeof(*ptr), GFP_KERNEL); + if (!ptr) { + err = -ENOMEM; + goto exit_ida; + } + + rtc = rtc_allocate_device(); + if (!rtc) { + err = -ENOMEM; + goto exit_devres; + } + + *ptr = rtc; + devres_add(dev, ptr); + + rtc->id = id; + rtc->dev.parent = dev; + dev_set_name(&rtc->dev, "rtc%d", id); + + return rtc; + +exit_devres: + devres_free(ptr); +exit_ida: + ida_simple_remove(&rtc_ida, id); + return ERR_PTR(err); +} +EXPORT_SYMBOL_GPL(devm_rtc_allocate_device); + +int __rtc_register_device(struct module *owner, struct rtc_device *rtc) +{ + struct rtc_wkalrm alrm; + int err; + + if (!rtc->ops) + return -EINVAL; + + rtc->owner = owner; + + /* Check to see if there is an ALARM already set in hw */ + err = __rtc_read_alarm(rtc, &alrm); + if (!err && !rtc_valid_tm(&alrm.time)) + rtc_initialize_alarm(rtc, &alrm); + + rtc_dev_prepare(rtc); + + err = cdev_device_add(&rtc->char_dev, &rtc->dev); + if (err) + dev_warn(rtc->dev.parent, "failed to add char device %d:%d\n", + MAJOR(rtc->dev.devt), rtc->id); + else + dev_dbg(rtc->dev.parent, "char device (%d:%d)\n", + MAJOR(rtc->dev.devt), rtc->id); + + rtc_proc_add_device(rtc); + + rtc->registered = true; + dev_info(rtc->dev.parent, "registered as %s\n", + dev_name(&rtc->dev)); + + return 0; +} +EXPORT_SYMBOL_GPL(__rtc_register_device); + static int __init rtc_init(void) { rtc_class = class_create(THIS_MODULE, "rtc"); diff --git a/include/linux/rtc.h b/include/linux/rtc.h index d354f56e0cf5..8e4a5f44f59e 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -142,6 +142,8 @@ struct rtc_device { /* Some hardware can't support UIE mode */ int uie_unsupported; + bool registered; + #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL struct work_struct uie_task; struct timer_list uie_timer; @@ -163,6 +165,8 @@ extern struct rtc_device *devm_rtc_device_register(struct device *dev, const char *name, const struct rtc_class_ops *ops, struct module *owner); +struct rtc_device *devm_rtc_allocate_device(struct device *dev); +int __rtc_register_device(struct module *owner, struct rtc_device *rtc); extern void rtc_device_unregister(struct rtc_device *rtc); extern void devm_rtc_device_unregister(struct device *dev, struct rtc_device *rtc); @@ -218,6 +222,9 @@ static inline bool is_leap_year(unsigned int year) return (!(year % 4) && (year % 100)) || !(year % 400); } +#define rtc_register_device(device) \ + __rtc_register_device(THIS_MODULE, device) + #ifdef CONFIG_RTC_HCTOSYS_DEVICE extern int rtc_hctosys_ret; #else -- cgit v1.2.3-71-gd317 From 697e5a47aa12cdab6f2a8b284cc923cdf704eafc Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Thu, 6 Jul 2017 11:42:02 +0200 Subject: rtc: add generic nvmem support Many RTCs have an on board non volatile storage. It can be battery backed RAM or an EEPROM. Use the nvmem subsystem to export it to both userspace and in-kernel consumers. This stays compatible with the previous (non documented) ABI that was using /sys/class/rtc/rtcx/device/nvram to export that memory. But will warn about the deprecation. Signed-off-by: Alexandre Belloni --- Documentation/rtc.txt | 2 + drivers/rtc/Kconfig | 8 ++++ drivers/rtc/Makefile | 1 + drivers/rtc/class.c | 4 ++ drivers/rtc/nvmem.c | 113 +++++++++++++++++++++++++++++++++++++++++++++++++ drivers/rtc/rtc-core.h | 8 ++++ include/linux/rtc.h | 7 +++ 7 files changed, 143 insertions(+) create mode 100644 drivers/rtc/nvmem.c (limited to 'include') diff --git a/Documentation/rtc.txt b/Documentation/rtc.txt index 47feb4414b7e..c0c977445fb9 100644 --- a/Documentation/rtc.txt +++ b/Documentation/rtc.txt @@ -164,6 +164,8 @@ offset The amount which the rtc clock has been adjusted in firmware. which are added to or removed from the rtc's base clock per billion ticks. A positive value makes a day pass more slowly, longer, and a negative value makes a day pass more quickly. +*/nvmem The non volatile storage exported as a raw file, as described + in Documentation/nvmem/nvmem.txt ================ ============================================================== IOCTL interface diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index d0e4b4a1c2a1..72419ac2c52a 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -77,6 +77,14 @@ config RTC_DEBUG Say yes here to enable debugging support in the RTC framework and individual RTC drivers. +config RTC_NVMEM + bool "RTC non volatile storage support" + select NVMEM + default RTC_CLASS + help + Say yes here to add support for the non volatile (often battery + backed) storage present on RTCs. + comment "RTC interfaces" config RTC_INTF_SYSFS diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 4050fc8b9271..acd366b41c85 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -15,6 +15,7 @@ ifdef CONFIG_RTC_DRV_EFI rtc-core-y += rtc-efi-platform.o endif +rtc-core-$(CONFIG_RTC_NVMEM) += nvmem.o rtc-core-$(CONFIG_RTC_INTF_DEV) += rtc-dev.o rtc-core-$(CONFIG_RTC_INTF_PROC) += rtc-proc.o rtc-core-$(CONFIG_RTC_INTF_SYSFS) += rtc-sysfs.o diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index 58e2a05765bb..2ed970d61da1 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -290,6 +290,8 @@ EXPORT_SYMBOL_GPL(rtc_device_register); */ void rtc_device_unregister(struct rtc_device *rtc) { + rtc_nvmem_unregister(rtc); + mutex_lock(&rtc->ops_lock); /* * Remove innards of this RTC, then disable it, before @@ -448,6 +450,8 @@ int __rtc_register_device(struct module *owner, struct rtc_device *rtc) rtc_proc_add_device(rtc); + rtc_nvmem_register(rtc); + rtc->registered = true; dev_info(rtc->dev.parent, "registered as %s\n", dev_name(&rtc->dev)); diff --git a/drivers/rtc/nvmem.c b/drivers/rtc/nvmem.c new file mode 100644 index 000000000000..8567b4ed9ac6 --- /dev/null +++ b/drivers/rtc/nvmem.c @@ -0,0 +1,113 @@ +/* + * RTC subsystem, nvmem interface + * + * Copyright (C) 2017 Alexandre Belloni + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include + +#include "rtc-core.h" + +/* + * Deprecated ABI compatibility, this should be removed at some point + */ + +static const char nvram_warning[] = "Deprecated ABI, please use nvmem"; + +static ssize_t +rtc_nvram_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *attr, + char *buf, loff_t off, size_t count) +{ + struct rtc_device *rtc = attr->private; + + dev_warn_once(kobj_to_dev(kobj), nvram_warning); + + return nvmem_device_read(rtc->nvmem, off, count, buf); +} + +static ssize_t +rtc_nvram_write(struct file *filp, struct kobject *kobj, + struct bin_attribute *attr, + char *buf, loff_t off, size_t count) +{ + struct rtc_device *rtc = attr->private; + + dev_warn_once(kobj_to_dev(kobj), nvram_warning); + + return nvmem_device_write(rtc->nvmem, off, count, buf); +} + +static int rtc_nvram_register(struct rtc_device *rtc) +{ + int err; + + rtc->nvram = devm_kzalloc(rtc->dev.parent, + sizeof(struct bin_attribute), + GFP_KERNEL); + if (!rtc->nvram) + return -ENOMEM; + + rtc->nvram->attr.name = "nvram"; + rtc->nvram->attr.mode = 0644; + rtc->nvram->private = rtc; + + sysfs_bin_attr_init(rtc->nvram); + + rtc->nvram->read = rtc_nvram_read; + rtc->nvram->write = rtc_nvram_write; + rtc->nvram->size = rtc->nvmem_config->size; + + err = sysfs_create_bin_file(&rtc->dev.parent->kobj, + rtc->nvram); + if (err) { + devm_kfree(rtc->dev.parent, rtc->nvram); + rtc->nvram = NULL; + } + + return err; +} + +static void rtc_nvram_unregister(struct rtc_device *rtc) +{ + sysfs_remove_bin_file(&rtc->dev.parent->kobj, rtc->nvram); +} + +/* + * New ABI, uses nvmem + */ +void rtc_nvmem_register(struct rtc_device *rtc) +{ + if (!rtc->nvmem_config) + return; + + rtc->nvmem_config->dev = &rtc->dev; + rtc->nvmem_config->owner = rtc->owner; + rtc->nvmem = nvmem_register(rtc->nvmem_config); + if (IS_ERR_OR_NULL(rtc->nvmem)) + return; + + /* Register the old ABI */ + if (rtc->nvram_old_abi) + rtc_nvram_register(rtc); +} + +void rtc_nvmem_unregister(struct rtc_device *rtc) +{ + if (IS_ERR_OR_NULL(rtc->nvmem)) + return; + + /* unregister the old ABI */ + if (rtc->nvram) + rtc_nvram_unregister(rtc); + + nvmem_unregister(rtc->nvmem); +} diff --git a/drivers/rtc/rtc-core.h b/drivers/rtc/rtc-core.h index 7a4ed2f7c7d7..ecab76a3207c 100644 --- a/drivers/rtc/rtc-core.h +++ b/drivers/rtc/rtc-core.h @@ -45,3 +45,11 @@ static inline const struct attribute_group **rtc_get_dev_attribute_groups(void) return NULL; } #endif + +#ifdef CONFIG_RTC_NVMEM +void rtc_nvmem_register(struct rtc_device *rtc); +void rtc_nvmem_unregister(struct rtc_device *rtc); +#else +static inline void rtc_nvmem_register(struct rtc_device *rtc) {} +static inline void rtc_nvmem_unregister(struct rtc_device *rtc) {} +#endif diff --git a/include/linux/rtc.h b/include/linux/rtc.h index 8e4a5f44f59e..d53ecdc060cf 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -14,6 +14,7 @@ #include #include +#include #include extern int rtc_month_days(unsigned int month, unsigned int year); @@ -144,6 +145,12 @@ struct rtc_device { bool registered; + struct nvmem_config *nvmem_config; + struct nvmem_device *nvmem; + /* Old ABI support */ + bool nvram_old_abi; + struct bin_attribute *nvram; + #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL struct work_struct uie_task; struct timer_list uie_timer; -- cgit v1.2.3-71-gd317 From 42a6e0996084972574e0a2b23e7326b78b0f64c5 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 10 Jul 2017 13:22:50 +0200 Subject: nvmem: include linux/err.h from header The new support for nvmem devices from the rtc layer caused a build error in some configurations: include/linux/nvmem-provider.h: In function 'nvmem_register': include/linux/nvmem-provider.h:51:9: error: implicit declaration of function 'ERR_PTR' [-Werror=implicit-function-declaration] This adds the missing include to ensure we can always include the header. Fixes: 697e5a47aa12 ("rtc: add generic nvmem support") Signed-off-by: Arnd Bergmann Acked-by: Srinivas Kandagatla Signed-off-by: Alexandre Belloni --- include/linux/nvmem-provider.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h index cd93416d762e..497706f5adca 100644 --- a/include/linux/nvmem-provider.h +++ b/include/linux/nvmem-provider.h @@ -12,6 +12,9 @@ #ifndef _LINUX_NVMEM_PROVIDER_H #define _LINUX_NVMEM_PROVIDER_H +#include +#include + struct nvmem_device; struct nvmem_cell_info; typedef int (*nvmem_reg_read_t)(void *priv, unsigned int offset, -- cgit v1.2.3-71-gd317 From 40bf6a35483ee25271ce2a90d8976cf1409a033a Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Wed, 12 Jul 2017 10:23:13 +0200 Subject: rtc: Remove wrong deprecation comment rtc_time_to_tm and rtc_tm_to_time are not deprecated and make perfect sense for RTCs that are simple 32bit counters. Signed-off-by: Alexandre Belloni --- include/linux/rtc.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include') diff --git a/include/linux/rtc.h b/include/linux/rtc.h index d53ecdc060cf..0a0f0d14a5fb 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -33,17 +33,11 @@ static inline time64_t rtc_tm_sub(struct rtc_time *lhs, struct rtc_time *rhs) return rtc_tm_to_time64(lhs) - rtc_tm_to_time64(rhs); } -/** - * Deprecated. Use rtc_time64_to_tm(). - */ static inline void rtc_time_to_tm(unsigned long time, struct rtc_time *tm) { rtc_time64_to_tm(time, tm); } -/** - * Deprecated. Use rtc_tm_to_time64(). - */ static inline int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time) { *time = rtc_tm_to_time64(tm); -- cgit v1.2.3-71-gd317