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authorAustin Boyle <Austin.Boyle@aviatnet.com>2012-03-23 15:02:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-23 16:58:40 -0700
commit9eab0a788d2d6e513f43b7c0e5bb9d60446233cb (patch)
tree74b0e4386fbfd3b0ca58596bdb0616e57244a58d /drivers/rtc/rtc-ds1307.c
parent40ce972d59fcfd4979e5de04456122447b40c1cf (diff)
rtc: ds1307: generalise ram size and offset
Generalise NVRAM to support RAM with other size and offset, such as the 64 bytes of SRAM on the mcp7941x. [rdunlap@xenotime.net: fix printk format warning] Signed-off-by: Austin Boyle <Austin.Boyle@aviatnet.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Cc: David Anders <danders.dev@gmail.com> Cc: Alessandro Zummo <alessandro.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/rtc/rtc-ds1307.c')
-rw-r--r--drivers/rtc/rtc-ds1307.c78
1 files changed, 47 insertions, 31 deletions
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 84ab971978c..cd188ab72f7 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -105,6 +105,8 @@ enum ds_type {
struct ds1307 {
u8 offset; /* register's offset */
u8 regs[11];
+ u16 nvram_offset;
+ struct bin_attribute *nvram;
enum ds_type type;
unsigned long flags;
#define HAS_NVRAM 0 /* bit 0 == sysfs file active */
@@ -119,19 +121,22 @@ struct ds1307 {
};
struct chip_desc {
- unsigned nvram56:1;
unsigned alarm:1;
+ u16 nvram_offset;
+ u16 nvram_size;
};
static const struct chip_desc chips[last_ds_type] = {
[ds_1307] = {
- .nvram56 = 1,
+ .nvram_offset = 8,
+ .nvram_size = 56,
},
[ds_1337] = {
.alarm = 1,
},
[ds_1338] = {
- .nvram56 = 1,
+ .nvram_offset = 8,
+ .nvram_size = 56,
},
[ds_1339] = {
.alarm = 1,
@@ -139,6 +144,11 @@ static const struct chip_desc chips[last_ds_type] = {
[ds_3231] = {
.alarm = 1,
},
+ [mcp7941x] = {
+ /* this is battery backed SRAM */
+ .nvram_offset = 0x20,
+ .nvram_size = 0x40,
+ },
};
static const struct i2c_device_id ds1307_id[] = {
@@ -543,8 +553,6 @@ static const struct rtc_class_ops ds13xx_rtc_ops = {
/*----------------------------------------------------------------------*/
-#define NVRAM_SIZE 56
-
static ssize_t
ds1307_nvram_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *attr,
@@ -557,14 +565,15 @@ ds1307_nvram_read(struct file *filp, struct kobject *kobj,
client = kobj_to_i2c_client(kobj);
ds1307 = i2c_get_clientdata(client);
- if (unlikely(off >= NVRAM_SIZE))
+ if (unlikely(off >= ds1307->nvram->size))
return 0;
- if ((off + count) > NVRAM_SIZE)
- count = NVRAM_SIZE - off;
+ if ((off + count) > ds1307->nvram->size)
+ count = ds1307->nvram->size - off;
if (unlikely(!count))
return count;
- result = ds1307->read_block_data(client, 8 + off, count, buf);
+ result = ds1307->read_block_data(client, ds1307->nvram_offset + off,
+ count, buf);
if (result < 0)
dev_err(&client->dev, "%s error %d\n", "nvram read", result);
return result;
@@ -582,14 +591,15 @@ ds1307_nvram_write(struct file *filp, struct kobject *kobj,
client = kobj_to_i2c_client(kobj);
ds1307 = i2c_get_clientdata(client);
- if (unlikely(off >= NVRAM_SIZE))
+ if (unlikely(off >= ds1307->nvram->size))
return -EFBIG;
- if ((off + count) > NVRAM_SIZE)
- count = NVRAM_SIZE - off;
+ if ((off + count) > ds1307->nvram->size)
+ count = ds1307->nvram->size - off;
if (unlikely(!count))
return count;
- result = ds1307->write_block_data(client, 8 + off, count, buf);
+ result = ds1307->write_block_data(client, ds1307->nvram_offset + off,
+ count, buf);
if (result < 0) {
dev_err(&client->dev, "%s error %d\n", "nvram write", result);
return result;
@@ -597,17 +607,6 @@ ds1307_nvram_write(struct file *filp, struct kobject *kobj,
return count;
}
-static struct bin_attribute nvram = {
- .attr = {
- .name = "nvram",
- .mode = S_IRUGO | S_IWUSR,
- },
-
- .read = ds1307_nvram_read,
- .write = ds1307_nvram_write,
- .size = NVRAM_SIZE,
-};
-
/*----------------------------------------------------------------------*/
static int __devinit ds1307_probe(struct i2c_client *client,
@@ -894,16 +893,31 @@ read_rtc:
dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
}
- if (chip->nvram56) {
- err = sysfs_create_bin_file(&client->dev.kobj, &nvram);
- if (err == 0) {
- set_bit(HAS_NVRAM, &ds1307->flags);
- dev_info(&client->dev, "56 bytes nvram\n");
+ if (chip->nvram_size) {
+ ds1307->nvram = kzalloc(sizeof(struct bin_attribute),
+ GFP_KERNEL);
+ if (!ds1307->nvram) {
+ err = -ENOMEM;
+ goto exit_nvram;
+ }
+ ds1307->nvram->attr.name = "nvram";
+ ds1307->nvram->attr.mode = S_IRUGO | S_IWUSR;
+ ds1307->nvram->read = ds1307_nvram_read,
+ ds1307->nvram->write = ds1307_nvram_write,
+ ds1307->nvram->size = chip->nvram_size;
+ ds1307->nvram_offset = chip->nvram_offset;
+ err = sysfs_create_bin_file(&client->dev.kobj, ds1307->nvram);
+ if (err) {
+ kfree(ds1307->nvram);
+ goto exit_nvram;
}
+ set_bit(HAS_NVRAM, &ds1307->flags);
+ dev_info(&client->dev, "%zu bytes nvram\n", ds1307->nvram->size);
}
return 0;
+exit_nvram:
exit_irq:
rtc_device_unregister(ds1307->rtc);
exit_free:
@@ -920,8 +934,10 @@ static int __devexit ds1307_remove(struct i2c_client *client)
cancel_work_sync(&ds1307->work);
}
- if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
- sysfs_remove_bin_file(&client->dev.kobj, &nvram);
+ if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags)) {
+ sysfs_remove_bin_file(&client->dev.kobj, ds1307->nvram);
+ kfree(ds1307->nvram);
+ }
rtc_device_unregister(ds1307->rtc);
kfree(ds1307);