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rtc: ds1742: use generic nvmem 

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@bootlin.com>
This commit is contained in:
Alexandre Belloni 2018-02-12 23:47:48 +01:00
parent 1358e7b2b3
commit 87c78d9512
1 changed files with 26 additions and 41 deletions
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67
drivers/rtc/rtc-ds1742.c
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@ -53,9 +53,7 @@
struct rtc_plat_data {
void __iomem *ioaddr_nvram;
void __iomem *ioaddr_rtc;
size_t size_nvram;
unsigned long last_jiffies;
struct bin_attribute nvram_attr;
};
static int ds1742_rtc_set_time(struct device *dev, struct rtc_time *tm)
@ -122,34 +120,28 @@ static const struct rtc_class_ops ds1742_rtc_ops = {
.set_time = ds1742_rtc_set_time,
};
static ssize_t ds1742_nvram_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t pos, size_t size)
static int ds1742_nvram_read(void *priv, unsigned int pos, void *val,
size_t bytes)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct platform_device *pdev = to_platform_device(dev);
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
struct rtc_plat_data *pdata = priv;
void __iomem *ioaddr = pdata->ioaddr_nvram;
ssize_t count;
u8 *buf = val;
for (count = 0; count < size; count++)
for (; bytes; bytes--)
*buf++ = readb(ioaddr + pos++);
return count;
return 0;
}
static ssize_t ds1742_nvram_write(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t pos, size_t size)
static int ds1742_nvram_write(void *priv, unsigned int pos, void *val,
size_t bytes)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct platform_device *pdev = to_platform_device(dev);
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
struct rtc_plat_data *pdata = priv;
void __iomem *ioaddr = pdata->ioaddr_nvram;
ssize_t count;
u8 *buf = val;
for (count = 0; count < size; count++)
for (; bytes; bytes--)
writeb(*buf++, ioaddr + pos++);
return count;
return 0;
}
static int ds1742_rtc_probe(struct platform_device *pdev)
@ -160,6 +152,14 @@ static int ds1742_rtc_probe(struct platform_device *pdev)
struct rtc_plat_data *pdata;
void __iomem *ioaddr;
int ret = 0;
struct nvmem_config nvmem_cfg = {
.name = "ds1742_nvram",
.word_size = 1,
.stride = 1,
.reg_read = ds1742_nvram_read,
.reg_write = ds1742_nvram_write,
};
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
@ -171,15 +171,10 @@ static int ds1742_rtc_probe(struct platform_device *pdev)
return PTR_ERR(ioaddr);
pdata->ioaddr_nvram = ioaddr;
pdata->size_nvram = resource_size(res) - RTC_SIZE;
pdata->ioaddr_rtc = ioaddr + pdata->size_nvram;
pdata->ioaddr_rtc = ioaddr + resource_size(res) - RTC_SIZE;
sysfs_bin_attr_init(&pdata->nvram_attr);
pdata->nvram_attr.attr.name = "nvram";
pdata->nvram_attr.attr.mode = S_IRUGO | S_IWUSR;
pdata->nvram_attr.read = ds1742_nvram_read;
pdata->nvram_attr.write = ds1742_nvram_write;
pdata->nvram_attr.size = pdata->size_nvram;
nvmem_cfg.size = resource_size(res) - RTC_SIZE;
nvmem_cfg.priv = pdata;
/* turn RTC on if it was not on */
ioaddr = pdata->ioaddr_rtc;
@ -202,27 +197,18 @@ static int ds1742_rtc_probe(struct platform_device *pdev)
return PTR_ERR(rtc);
rtc->ops = &ds1742_rtc_ops;
rtc->nvram_old_abi = true;
ret = rtc_register_device(rtc);
if (ret)
return ret;
ret = sysfs_create_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
if (ret)
dev_err(&pdev->dev, "Unable to create sysfs entry: %s\n",
pdata->nvram_attr.attr.name);
if (rtc_nvmem_register(rtc, &nvmem_cfg))
dev_err(&pdev->dev, "Unable to register nvmem\n");
return 0;
}
static int ds1742_rtc_remove(struct platform_device *pdev)
{
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
sysfs_remove_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
return 0;
}
static const struct of_device_id __maybe_unused ds1742_rtc_of_match[] = {
{ .compatible = "maxim,ds1742", },
{ }
@ -231,7 +217,6 @@ MODULE_DEVICE_TABLE(of, ds1742_rtc_of_match);
static struct platform_driver ds1742_rtc_driver = {
.probe = ds1742_rtc_probe,
.remove = ds1742_rtc_remove,
.driver = {
.name = "rtc-ds1742",
.of_match_table = of_match_ptr(ds1742_rtc_of_match),