rtc: ds1553: 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>

diff --git a/drivers/rtc/rtc-ds1553.c b/drivers/rtc/rtc-ds1553.c
index 59eab5e..6205c28 100644 (file)
--- a/drivers/rtc/rtc-ds1553.c
+++ b/drivers/rtc/rtc-ds1553.c
@@ -233,46 +233,32 @@ static const struct rtc_class_ops ds1553_rtc_ops = {
        .alarm_irq_enable       = ds1553_rtc_alarm_irq_enable,
 };
 
-static ssize_t ds1553_nvram_read(struct file *filp, struct kobject *kobj,
-                                struct bin_attribute *bin_attr,
-                                char *buf, loff_t pos, size_t size)
+static int ds1553_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 platform_device *pdev = priv;
        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
        void __iomem *ioaddr = pdata->ioaddr;
-       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 ds1553_nvram_write(struct file *filp, struct kobject *kobj,
-                                 struct bin_attribute *bin_attr,
-                                 char *buf, loff_t pos, size_t size)
+static int ds1553_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 platform_device *pdev = priv;
        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
        void __iomem *ioaddr = pdata->ioaddr;
-       ssize_t count;
+       u8 *buf = val;
 
-       for (count = 0; count < size; count++)
+       for (; bytes; bytes--)
                writeb(*buf++, ioaddr + pos++);
-       return count;
+       return 0;
 }
 
-static struct bin_attribute ds1553_nvram_attr = {
-       .attr = {
-               .name = "nvram",
-               .mode = S_IRUGO | S_IWUSR,
-       },
-       .size = RTC_OFFSET,
-       .read = ds1553_nvram_read,
-       .write = ds1553_nvram_write,
-};
-
 static int ds1553_rtc_probe(struct platform_device *pdev)
 {
        struct resource *res;
@@ -280,6 +266,15 @@ static int ds1553_rtc_probe(struct platform_device *pdev)
        struct rtc_plat_data *pdata;
        void __iomem *ioaddr;
        int ret = 0;
+       struct nvmem_config nvmem_cfg = {
+               .name = "ds1553_nvram",
+               .word_size = 1,
+               .stride = 1,
+               .size = RTC_OFFSET,
+               .reg_read = ds1553_nvram_read,
+               .reg_write = ds1553_nvram_write,
+               .priv = pdev,
+       };
 
        pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
@@ -313,6 +308,7 @@ static int ds1553_rtc_probe(struct platform_device *pdev)
                return PTR_ERR(pdata->rtc);
 
        pdata->rtc->ops = &ds1553_rtc_ops;
+       pdata->rtc->nvram_old_abi = true;
 
        ret = rtc_register_device(pdata->rtc);
        if (ret)
@@ -328,10 +324,8 @@ static int ds1553_rtc_probe(struct platform_device *pdev)
                }
        }
 
-       ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
-       if (ret)
-               dev_err(&pdev->dev, "unable to create sysfs file: %s\n",
-                       ds1553_nvram_attr.attr.name);
+       if (rtc_nvmem_register(pdata->rtc, &nvmem_cfg))
+               dev_err(&pdev->dev, "unable to register nvmem\n");
 
        return 0;
 }
@@ -340,7 +334,6 @@ static int ds1553_rtc_remove(struct platform_device *pdev)
 {
        struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 
-       sysfs_remove_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
        if (pdata->irq > 0)
                writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
        return 0;