@@ -38,6 +38,8 @@
#define M48T86_C 0x0c
#define M48T86_D 0x0d
#define M48T86_D_VRT BIT(7)
+#define M48T86_NVRAM(x) (0x0e + (x))
+#define M48T86_NVRAM_LEN 114
struct m48t86_rtc_info {
void __iomem *index_reg;
@@ -170,6 +172,35 @@ static const struct rtc_class_ops m48t86_rtc_ops = {
.proc = m48t86_rtc_proc,
};
+static ssize_t m48t86_nvram_read(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *attr,
+ char *buf, loff_t off, size_t count)
+{
+ struct device *dev = kobj_to_dev(kobj);
+ unsigned int i;
+
+ for (i = 0; i < count; i++)
+ buf[i] = m48t86_readb(dev, M48T86_NVRAM(off + i));
+
+ return count;
+}
+
+static ssize_t m48t86_nvram_write(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *attr,
+ char *buf, loff_t off, size_t count)
+{
+ struct device *dev = kobj_to_dev(kobj);
+ unsigned int i;
+
+ for (i = 0; i < count; i++)
+ m48t86_writeb(dev, buf[i], M48T86_NVRAM(off + i));
+
+ return count;
+}
+
+static BIN_ATTR(nvram, 0644, m48t86_nvram_read, m48t86_nvram_write,
+ M48T86_NVRAM_LEN);
+
static int m48t86_rtc_probe(struct platform_device *pdev)
{
struct m48t86_rtc_info *info;
@@ -210,6 +241,15 @@ static int m48t86_rtc_probe(struct platform_device *pdev)
dev_info(&pdev->dev, "battery %s\n",
(reg & M48T86_D_VRT) ? "ok" : "exhausted");
+ if (device_create_bin_file(&pdev->dev, &bin_attr_nvram))
+ dev_err(&pdev->dev, "failed to create nvram sysfs entry\n");
+
+ return 0;
+}
+
+static int m48t86_rtc_remove(struct platform_device *pdev)
+{
+ device_remove_bin_file(&pdev->dev, &bin_attr_nvram);
return 0;
}
@@ -218,6 +258,7 @@ static struct platform_driver m48t86_rtc_platform_driver = {
.name = "rtc-m48t86",
},
.probe = m48t86_rtc_probe,
+ .remove = m48t86_rtc_remove,
};
module_platform_driver(m48t86_rtc_platform_driver);
This RTC has 114 bytes of NVRAM. Provide access to it via a biniary sysfs 'nvram' attribute file. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com> Cc: Alexander Clouter <alex@digriz.org.uk> --- drivers/rtc/rtc-m48t86.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+)