rtc: tx4939: use generic nvmem

Instead of adding a binary sysfs attribute from the driver, use the core to
register an nvmem device.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-tx4939.c

@@ -212,58 +212,52 @@ static const struct rtc_class_ops tx4939_rtc_ops = {
 	.alarm_irq_enable	= tx4939_rtc_alarm_irq_enable,
 };
 
-static ssize_t tx4939_rtc_nvram_read(struct file *filp, struct kobject *kobj,
-				     struct bin_attribute *bin_attr,
-				     char *buf, loff_t pos, size_t size)
+static int tx4939_nvram_read(void *priv, unsigned int pos, void *val,
+			     size_t bytes)
 {
-	struct device *dev = container_of(kobj, struct device, kobj);
-	struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+	struct tx4939rtc_plat_data *pdata = priv;
 	struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
-	ssize_t count;
+	u8 *buf = val;
 
 	spin_lock_irq(&pdata->lock);
-	for (count = 0; count < size; count++) {
+	for (; bytes; bytes--) {
 		__raw_writel(pos++, &rtcreg->adr);
 		*buf++ = __raw_readl(&rtcreg->dat);
 	}
 	spin_unlock_irq(&pdata->lock);
-	return count;
+	return 0;
 }
 
-static ssize_t tx4939_rtc_nvram_write(struct file *filp, struct kobject *kobj,
-				      struct bin_attribute *bin_attr,
-				      char *buf, loff_t pos, size_t size)
+static int tx4939_nvram_write(void *priv, unsigned int pos, void *val,
+			      size_t bytes)
 {
-	struct device *dev = container_of(kobj, struct device, kobj);
-	struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
+	struct tx4939rtc_plat_data *pdata = priv;
 	struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
-	ssize_t count;
+	u8 *buf = val;
 
 	spin_lock_irq(&pdata->lock);
-	for (count = 0; count < size; count++) {
+	for (; bytes; bytes--) {
 		__raw_writel(pos++, &rtcreg->adr);
 		__raw_writel(*buf++, &rtcreg->dat);
 	}
 	spin_unlock_irq(&pdata->lock);
-	return count;
+	return 0;
 }
 
-static struct bin_attribute tx4939_rtc_nvram_attr = {
-	.attr = {
-		.name = "nvram",
-		.mode = S_IRUGO | S_IWUSR,
-	},
-	.size = TX4939_RTC_REG_RAMSIZE,
-	.read = tx4939_rtc_nvram_read,
-	.write = tx4939_rtc_nvram_write,
-};
-
 static int __init tx4939_rtc_probe(struct platform_device *pdev)
 {
 	struct rtc_device *rtc;
 	struct tx4939rtc_plat_data *pdata;
 	struct resource *res;
 	int irq, ret;
+	struct nvmem_config nvmem_cfg = {
+		.name = "rv8803_nvram",
+		.word_size = 4,
+		.stride = 4,
+		.size = TX4939_RTC_REG_RAMSIZE,
+		.reg_read = tx4939_nvram_read,
+		.reg_write = tx4939_nvram_write,
+	};
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
@@ -288,23 +282,22 @@ static int __init tx4939_rtc_probe(struct platform_device *pdev)
 		return PTR_ERR(rtc);
 
 	rtc->ops = &tx4939_rtc_ops;
-
-	ret = sysfs_create_bin_file(&pdev->dev.kobj, &tx4939_rtc_nvram_attr);
-	if (ret)
-		return ret;
+	rtc->nvram_old_abi = true;
 
 	pdata->rtc = rtc;
 
-	ret = rtc_register_device(rtc);
-
+	nvmem_cfg.priv = pdata;
+	ret = rtc_nvmem_register(rtc, &nvmem_cfg);
+	if (ret)
 		return ret;
+
+	return rtc_register_device(rtc);
 }
 
 static int __exit tx4939_rtc_remove(struct platform_device *pdev)
 {
 	struct tx4939rtc_plat_data *pdata = platform_get_drvdata(pdev);
 
-	sysfs_remove_bin_file(&pdev->dev.kobj, &tx4939_rtc_nvram_attr);
 	spin_lock_irq(&pdata->lock);
 	tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP);
 	spin_unlock_irq(&pdata->lock);