[PATCH 2/2] rtc: nvmem: remove nvmem from struct rtc_device

[Alexandre Belloni]

Using devm_nvmem_register allows to avoid tracking the nvmem pointer in the
rtc_device structure.
This ultimately allows to register multiple nvmem devices from an RTC
driver.

Signed-off-by: Alexandre Belloni <alexandre.bell...@bootlin.com>
---
 drivers/rtc/nvmem.c | 24 ++++++++++--------------
 include/linux/rtc.h |  1 -
 2 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/drivers/rtc/nvmem.c b/drivers/rtc/nvmem.c
index 2a7220d8b02d..ebdfe8e3a1a0 100644
--- a/drivers/rtc/nvmem.c
+++ b/drivers/rtc/nvmem.c
@@ -25,11 +25,9 @@ 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);
+       return nvmem_device_read(attr->private, off, count, buf);
 }
 
 static ssize_t
@@ -37,14 +35,13 @@ 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);
+       return nvmem_device_write(attr->private, off, count, buf);
 }
 
-static int rtc_nvram_register(struct rtc_device *rtc, size_t size)
+static int rtc_nvram_register(struct rtc_device *rtc,
+                             struct nvmem_device *nvmem, size_t size)
 {
        int err;
 
@@ -56,7 +53,7 @@ static int rtc_nvram_register(struct rtc_device *rtc, size_t 
size)
 
        rtc->nvram->attr.name = "nvram";
        rtc->nvram->attr.mode = 0644;
-       rtc->nvram->private = rtc;
+       rtc->nvram->private = nvmem;
 
        sysfs_bin_attr_init(rtc->nvram);
 
@@ -85,21 +82,20 @@ static void rtc_nvram_unregister(struct rtc_device *rtc)
 int rtc_nvmem_register(struct rtc_device *rtc,
                       struct nvmem_config *nvmem_config)
 {
-       if (!IS_ERR_OR_NULL(rtc->nvmem))
-               return -EBUSY;
+       struct nvmem_device *nvmem;
 
        if (!nvmem_config)
                return -ENODEV;
 
        nvmem_config->dev = rtc->dev.parent;
        nvmem_config->owner = rtc->owner;
-       rtc->nvmem = devm_nvmem_register(rtc->dev.parent, nvmem_config);
-       if (IS_ERR(rtc->nvmem))
-               return PTR_ERR(rtc->nvmem);
+       nvmem = devm_nvmem_register(rtc->dev.parent, nvmem_config);
+       if (IS_ERR(nvmem))
+               return PTR_ERR(nvmem);
 
        /* Register the old ABI */
        if (rtc->nvram_old_abi)
-               rtc_nvram_register(rtc, nvmem_config->size);
+               rtc_nvram_register(rtc, nvmem, nvmem_config->size);
 
        return 0;
 }
diff --git a/include/linux/rtc.h b/include/linux/rtc.h
index c8bb4a2b48c3..40ecdb5a369e 100644
--- a/include/linux/rtc.h
+++ b/include/linux/rtc.h
@@ -138,7 +138,6 @@ struct rtc_device {
 
        bool registered;
 
-       struct nvmem_device *nvmem;
        /* Old ABI support */
        bool nvram_old_abi;
        struct bin_attribute *nvram;
-- 
2.19.1