[PATCH 07/11] rtc: rv8803: use generic nvmem support

From: Alexandre Belloni
Date: Thu Jul 06 2017 - 05:44:30 EST


Instead of adding a binary sysfs attribute from the driver (which suffers
from a race condition as the attribute appears after the device), use the
core to register an nvmem device.

Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
---
drivers/rtc/rtc-rv8803.c | 51 +++++++++++++++++++-----------------------------
1 file changed, 20 insertions(+), 31 deletions(-)

diff --git a/drivers/rtc/rtc-rv8803.c b/drivers/rtc/rtc-rv8803.c
index 209edbb03971..10474ab7887d 100644
--- a/drivers/rtc/rtc-rv8803.c
+++ b/drivers/rtc/rtc-rv8803.c
@@ -68,6 +68,7 @@ struct rv8803_data {
struct mutex flags_lock;
u8 ctrl;
enum rv8803_type type;
+ struct nvmem_config nvmem_cfg;
};

static int rv8803_read_reg(const struct i2c_client *client, u8 reg)
@@ -460,48 +461,32 @@ static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
}
}

-static ssize_t rv8803_nvram_write(struct file *filp, struct kobject *kobj,
- struct bin_attribute *attr,
- char *buf, loff_t off, size_t count)
+static int rv8803_nvram_write(void *priv, unsigned int offset, void *val,
+ size_t bytes)
{
- struct device *dev = kobj_to_dev(kobj);
- struct i2c_client *client = to_i2c_client(dev);
int ret;

- ret = rv8803_write_reg(client, RV8803_RAM, buf[0]);
+ ret = rv8803_write_reg(priv, RV8803_RAM, *(u8 *)val);
if (ret)
return ret;

- return 1;
+ return 0;
}

-static ssize_t rv8803_nvram_read(struct file *filp, struct kobject *kobj,
- struct bin_attribute *attr,
- char *buf, loff_t off, size_t count)
+static int rv8803_nvram_read(void *priv, unsigned int offset,
+ void *val, size_t bytes)
{
- struct device *dev = kobj_to_dev(kobj);
- struct i2c_client *client = to_i2c_client(dev);
int ret;

- ret = rv8803_read_reg(client, RV8803_RAM);
+ ret = rv8803_read_reg(priv, RV8803_RAM);
if (ret < 0)
return ret;

- buf[0] = ret;
+ *(u8 *)val = ret;

- return 1;
+ return 0;
}

-static struct bin_attribute rv8803_nvram_attr = {
- .attr = {
- .name = "nvram",
- .mode = S_IRUGO | S_IWUSR,
- },
- .size = 1,
- .read = rv8803_nvram_read,
- .write = rv8803_nvram_write,
-};
-
static struct rtc_class_ops rv8803_rtc_ops = {
.read_time = rv8803_get_time,
.set_time = rv8803_set_time,
@@ -597,7 +582,17 @@ static int rv8803_probe(struct i2c_client *client,
}
}

+ rv8803->nvmem_cfg.name = "rv8803_nvram",
+ rv8803->nvmem_cfg.word_size = 1,
+ rv8803->nvmem_cfg.stride = 1,
+ rv8803->nvmem_cfg.size = 1,
+ rv8803->nvmem_cfg.reg_read = rv8803_nvram_read,
+ rv8803->nvmem_cfg.reg_write = rv8803_nvram_write,
+ rv8803->nvmem_cfg.priv = client;
+
rv8803->rtc->ops = &rv8803_rtc_ops;
+ rv8803->rtc->nvmem_config = &rv8803->nvmem_cfg;
+ rv8803->rtc->nvram_old_abi = true;
err = rtc_register_device(rv8803->rtc);
if (err)
return err;
@@ -612,10 +607,6 @@ static int rv8803_probe(struct i2c_client *client,
return err;
}

- err = device_create_bin_file(&client->dev, &rv8803_nvram_attr);
- if (err)
- return err;
-
rv8803->rtc->max_user_freq = 1;

return 0;
@@ -623,8 +614,6 @@ static int rv8803_probe(struct i2c_client *client,

static int rv8803_remove(struct i2c_client *client)
{
- device_remove_bin_file(&client->dev, &rv8803_nvram_attr);
-
return 0;
}

--
2.11.0