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path: root/drivers/rtc/rtc-ds1307.c
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Diffstat (limited to 'drivers/rtc/rtc-ds1307.c')
-rw-r--r--drivers/rtc/rtc-ds1307.c182
1 files changed, 94 insertions, 88 deletions
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 62b0763b7b9..cd188ab72f7 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -20,7 +20,8 @@
-/* We can't determine type by probing, but if we expect pre-Linux code
+/*
+ * We can't determine type by probing, but if we expect pre-Linux code
* to have set the chip up as a clock (turning on the oscillator and
* setting the date and time), Linux can ignore the non-clock features.
* That's a natural job for a factory or repair bench.
@@ -36,7 +37,8 @@ enum ds_type {
m41t00,
mcp7941x,
rx_8025,
- // rs5c372 too? different address...
+ last_ds_type /* always last */
+ /* rs5c372 too? different address... */
};
@@ -58,7 +60,8 @@ enum ds_type {
# define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */
#define DS1307_REG_YEAR 0x06 /* 00-99 */
-/* Other registers (control, status, alarms, trickle charge, NVRAM, etc)
+/*
+ * Other registers (control, status, alarms, trickle charge, NVRAM, etc)
* start at 7, and they differ a LOT. Only control and status matter for
* basic RTC date and time functionality; be careful using them.
*/
@@ -102,6 +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 */
@@ -116,34 +121,35 @@ struct ds1307 {
};
struct chip_desc {
- unsigned nvram56:1;
unsigned alarm:1;
+ u16 nvram_offset;
+ u16 nvram_size;
};
-static const struct chip_desc chips[] = {
-[ds_1307] = {
- .nvram56 = 1,
-},
-[ds_1337] = {
- .alarm = 1,
-},
-[ds_1338] = {
- .nvram56 = 1,
-},
-[ds_1339] = {
- .alarm = 1,
-},
-[ds_1340] = {
-},
-[ds_3231] = {
- .alarm = 1,
-},
-[m41t00] = {
-},
-[mcp7941x] = {
-},
-[rx_8025] = {
-}, };
+static const struct chip_desc chips[last_ds_type] = {
+ [ds_1307] = {
+ .nvram_offset = 8,
+ .nvram_size = 56,
+ },
+ [ds_1337] = {
+ .alarm = 1,
+ },
+ [ds_1338] = {
+ .nvram_offset = 8,
+ .nvram_size = 56,
+ },
+ [ds_1339] = {
+ .alarm = 1,
+ },
+ [ds_3231] = {
+ .alarm = 1,
+ },
+ [mcp7941x] = {
+ /* this is battery backed SRAM */
+ .nvram_offset = 0x20,
+ .nvram_size = 0x40,
+ },
+};
static const struct i2c_device_id ds1307_id[] = {
{ "ds1307", ds_1307 },
@@ -372,6 +378,11 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
| DS1340_BIT_CENTURY;
break;
case mcp7941x:
+ /*
+ * these bits were cleared when preparing the date/time
+ * values and need to be set again before writing the
+ * buffer out to the device.
+ */
buf[DS1307_REG_SECS] |= MCP7941X_BIT_ST;
buf[DS1307_REG_WDAY] |= MCP7941X_BIT_VBATEN;
break;
@@ -417,7 +428,8 @@ static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
ds1307->regs[6], ds1307->regs[7],
ds1307->regs[8]);
- /* report alarm time (ALARM1); assume 24 hour and day-of-month modes,
+ /*
+ * report alarm time (ALARM1); assume 24 hour and day-of-month modes,
* and that all four fields are checked matches
*/
t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
@@ -445,7 +457,7 @@ static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
- struct i2c_client *client = to_i2c_client(dev);
+ struct i2c_client *client = to_i2c_client(dev);
struct ds1307 *ds1307 = i2c_get_clientdata(client);
unsigned char *buf = ds1307->regs;
u8 control, status;
@@ -541,8 +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,
@@ -555,14 +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;
@@ -580,14 +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;
@@ -595,21 +607,8 @@ 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 struct i2c_driver ds1307_driver;
-
static int __devinit ds1307_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -630,7 +629,8 @@ static int __devinit ds1307_probe(struct i2c_client *client,
&& !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
return -EIO;
- if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL)))
+ ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL);
+ if (!ds1307)
return -ENOMEM;
i2c_set_clientdata(client, ds1307);
@@ -652,11 +652,6 @@ static int __devinit ds1307_probe(struct i2c_client *client,
case ds_1337:
case ds_1339:
case ds_3231:
- /* has IRQ? */
- if (ds1307->client->irq > 0 && chip->alarm) {
- INIT_WORK(&ds1307->work, ds1307_work);
- want_irq = true;
- }
/* get registers that the "rtc" read below won't read... */
tmp = ds1307->read_block_data(ds1307->client,
DS1337_REG_CONTROL, 2, buf);
@@ -670,14 +665,19 @@ static int __devinit ds1307_probe(struct i2c_client *client,
if (ds1307->regs[0] & DS1337_BIT_nEOSC)
ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
- /* Using IRQ? Disable the square wave and both alarms.
+ /*
+ * Using IRQ? Disable the square wave and both alarms.
* For some variants, be sure alarms can trigger when we're
* running on Vbackup (BBSQI/BBSQW)
*/
- if (want_irq) {
+ if (ds1307->client->irq > 0 && chip->alarm) {
+ INIT_WORK(&ds1307->work, ds1307_work);
+
ds1307->regs[0] |= DS1337_BIT_INTCN
| bbsqi_bitpos[ds1307->type];
ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
+
+ want_irq = true;
}
i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
@@ -772,7 +772,8 @@ read_rtc:
goto exit_free;
}
- /* minimal sanity checking; some chips (like DS1340) don't
+ /*
+ * minimal sanity checking; some chips (like DS1340) don't
* specify the extra bits as must-be-zero, but there are
* still a few values that are clearly out-of-range.
*/
@@ -836,11 +837,7 @@ read_rtc:
}
break;
- case rx_8025:
- case ds_1337:
- case ds_1339:
- case ds_1388:
- case ds_3231:
+ default:
break;
}
@@ -848,7 +845,8 @@ read_rtc:
switch (ds1307->type) {
case ds_1340:
case m41t00:
- /* NOTE: ignores century bits; fix before deploying
+ /*
+ * NOTE: ignores century bits; fix before deploying
* systems that will run through year 2100.
*/
break;
@@ -858,7 +856,8 @@ read_rtc:
if (!(tmp & DS1307_BIT_12HR))
break;
- /* Be sure we're in 24 hour mode. Multi-master systems
+ /*
+ * Be sure we're in 24 hour mode. Multi-master systems
* take note...
*/
tmp = bcd2bin(tmp & 0x1f);
@@ -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:
@@ -913,15 +927,17 @@ exit_free:
static int __devexit ds1307_remove(struct i2c_client *client)
{
- struct ds1307 *ds1307 = i2c_get_clientdata(client);
+ struct ds1307 *ds1307 = i2c_get_clientdata(client);
if (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) {
free_irq(client->irq, 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);
@@ -938,17 +954,7 @@ static struct i2c_driver ds1307_driver = {
.id_table = ds1307_id,
};
-static int __init ds1307_init(void)
-{
- return i2c_add_driver(&ds1307_driver);
-}
-module_init(ds1307_init);
-
-static void __exit ds1307_exit(void)
-{
- i2c_del_driver(&ds1307_driver);
-}
-module_exit(ds1307_exit);
+module_i2c_driver(ds1307_driver);
MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
MODULE_LICENSE("GPL");