diff options
| -rw-r--r-- | Documentation/rtc.txt | 2 | ||||
| -rw-r--r-- | drivers/rtc/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/rtc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/rtc/class.c | 4 | ||||
| -rw-r--r-- | drivers/rtc/nvmem.c | 113 | ||||
| -rw-r--r-- | drivers/rtc/rtc-core.h | 8 | ||||
| -rw-r--r-- | include/linux/rtc.h | 7 |
7 files changed, 143 insertions, 0 deletions
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 <linux/err.h> +#include <linux/types.h> +#include <linux/nvmem-consumer.h> +#include <linux/rtc.h> +#include <linux/sysfs.h> + +#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 <linux/types.h> #include <linux/interrupt.h> +#include <linux/nvmem-provider.h> #include <uapi/linux/rtc.h> 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; |