drivers/rtc/rtc-ds1343.c: add support of nvram for maxim dallas rtc ds1343

This is a patch to add support of nvram for maxim dallas rtc ds1343.

Signed-off-by: Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 73 insertions, 2 deletions

diff --git a/drivers/rtc/rtc-ds1343.c b/drivers/rtc/rtc-ds1343.c
index c3719189dd96..ae9f997223b1 100644
--- a/drivers/rtc/rtc-ds1343.c
+++ b/drivers/rtc/rtc-ds1343.c
@@ -4,6 +4,7 @@
  * Real Time Clock
  *
  * Author : Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>
+ *          Ankur Srivastava <sankurece@gmail.com> : DS1343 Nvram Support
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -45,6 +46,9 @@
 #define DS1343_CONTROL_REG      0x0F
 #define DS1343_STATUS_REG       0x10
 #define DS1343_TRICKLE_REG      0x11
+#define DS1343_NVRAM            0x20
+
+#define DS1343_NVRAM_LEN        96
 
 /* DS1343 Control Registers bits */
 #define DS1343_EOSC             0x80
@@ -149,6 +153,64 @@ static ssize_t ds1343_store_glitchfilter(struct device *dev,
 static DEVICE_ATTR(glitch_filter, S_IRUGO | S_IWUSR, ds1343_show_glitchfilter,
                         ds1343_store_glitchfilter);
 
+static ssize_t ds1343_nvram_write(struct file *filp, struct kobject *kobj,
+                        struct bin_attribute *attr,
+                        char *buf, loff_t off, size_t count)
+{
+        int ret;
+        unsigned char address;
+        struct device *dev = kobj_to_dev(kobj);
+        struct ds1343_priv *priv = dev_get_drvdata(dev);
+
+        if (unlikely(!count))
+                return count;
+
+        if ((count + off) > DS1343_NVRAM_LEN)
+                count = DS1343_NVRAM_LEN - off;
+
+        address = DS1343_NVRAM + off;
+
+        ret = regmap_bulk_write(priv->map, address, buf, count);
+        if (ret < 0)
+                dev_err(&priv->spi->dev, "Error in nvram write %d", ret);
+
+        return (ret < 0) ? ret : count;
+}
+
+
+static ssize_t ds1343_nvram_read(struct file *filp, struct kobject *kobj,
+                                struct bin_attribute *attr,
+                                char *buf, loff_t off, size_t count)
+{
+        int ret;
+        unsigned char address;
+        struct device *dev = kobj_to_dev(kobj);
+        struct ds1343_priv *priv = dev_get_drvdata(dev);
+
+        if (unlikely(!count))
+                return count;
+
+        if ((count + off) > DS1343_NVRAM_LEN)
+                count = DS1343_NVRAM_LEN - off;
+
+        address = DS1343_NVRAM + off;
+
+        ret = regmap_bulk_read(priv->map, address, buf, count);
+        if (ret < 0)
+                dev_err(&priv->spi->dev, "Error in nvram read %d\n", ret);
+
+        return (ret < 0) ? ret : count;
+}
+
+
+static struct bin_attribute nvram_attr = {
+        .attr.name      = "nvram",
+        .attr.mode      = S_IRUGO | S_IWUSR,
+        .read           = ds1343_nvram_read,
+        .write          = ds1343_nvram_write,
+        .size           = DS1343_NVRAM_LEN,
+};
+
 static ssize_t ds1343_show_alarmstatus(struct device *dev,
                                 struct device_attribute *attr, char *buf)
 {
@@ -274,12 +336,16 @@ static int ds1343_sysfs_register(struct device *dev)
         if (err)
                 goto error1;
 
+        err = device_create_bin_file(dev, &nvram_attr);
+        if (err)
+                goto error2;
+
         if (priv->irq <= 0)
                 return err;
 
         err = device_create_file(dev, &dev_attr_alarm_mode);
         if (err)
-                goto error2;
+                goto error3;
 
         err = device_create_file(dev, &dev_attr_alarm_status);
         if (!err)
@@ -287,6 +353,9 @@ static int ds1343_sysfs_register(struct device *dev)
 
         device_remove_file(dev, &dev_attr_alarm_mode);
 
+error3:
+        device_remove_bin_file(dev, &nvram_attr);
+
 error2:
         device_remove_file(dev, &dev_attr_trickle_charger);
 
@@ -302,6 +371,7 @@ static void ds1343_sysfs_unregister(struct device *dev)
 
         device_remove_file(dev, &dev_attr_glitch_filter);
         device_remove_file(dev, &dev_attr_trickle_charger);
+        device_remove_bin_file(dev, &nvram_attr);
 
         if (priv->irq <= 0)
                 return;
@@ -684,6 +754,7 @@ static struct spi_driver ds1343_driver = {
 module_spi_driver(ds1343_driver);
 
 MODULE_DESCRIPTION("DS1343 RTC SPI Driver");
-MODULE_AUTHOR("Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>");
+MODULE_AUTHOR("Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>,"
+                "Ankur Srivastava <sankurece@gmail.com>");
 MODULE_LICENSE("GPL v2");
 MODULE_VERSION(DS1343_DRV_VERSION);