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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.c300
1 files changed, 187 insertions, 113 deletions
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 3f0f7b8fa813..5158a625671f 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -24,29 +24,29 @@
* setting the date and time), Linux can ignore the non-clock features.
* That's a natural job for a factory or repair bench.
*
- * If the I2C "force" mechanism is used, we assume the chip is a ds1337.
- * (Much better would be board-specific tables of I2C devices, along with
- * the platform_data drivers would use to sort such issues out.)
+ * This is currently a simple no-alarms driver. If your board has the
+ * alarm irq wired up on a ds1337 or ds1339, and you want to use that,
+ * then look at the rtc-rs5c372 driver for code to steal...
*/
enum ds_type {
- unknown = 0,
- ds_1307, /* or ds1338, ... */
- ds_1337, /* or ds1339, ... */
- ds_1340, /* or st m41t00, ... */
+ ds_1307,
+ ds_1337,
+ ds_1338,
+ ds_1339,
+ ds_1340,
+ m41t00,
// rs5c372 too? different address...
};
-static unsigned short normal_i2c[] = { 0x68, I2C_CLIENT_END };
-
-I2C_CLIENT_INSMOD;
-
-
/* RTC registers don't differ much, except for the century flag */
#define DS1307_REG_SECS 0x00 /* 00-59 */
# define DS1307_BIT_CH 0x80
+# define DS1340_BIT_nEOSC 0x80
#define DS1307_REG_MIN 0x01 /* 00-59 */
#define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
+# define DS1307_BIT_12HR 0x40 /* in REG_HOUR */
+# define DS1307_BIT_PM 0x20 /* in REG_HOUR */
# define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
# define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
#define DS1307_REG_WDAY 0x03 /* 01-07 */
@@ -56,11 +56,12 @@ I2C_CLIENT_INSMOD;
#define DS1307_REG_YEAR 0x06 /* 00-99 */
/* Other registers (control, status, alarms, trickle charge, NVRAM, etc)
- * start at 7, and they differ a lot. Only control and status matter for RTC;
- * be careful using them.
+ * start at 7, and they differ a LOT. Only control and status matter for
+ * basic RTC date and time functionality; be careful using them.
*/
-#define DS1307_REG_CONTROL 0x07
+#define DS1307_REG_CONTROL 0x07 /* or ds1338 */
# define DS1307_BIT_OUT 0x80
+# define DS1338_BIT_OSF 0x20
# define DS1307_BIT_SQWE 0x10
# define DS1307_BIT_RS1 0x02
# define DS1307_BIT_RS0 0x01
@@ -71,6 +72,13 @@ I2C_CLIENT_INSMOD;
# define DS1337_BIT_INTCN 0x04
# define DS1337_BIT_A2IE 0x02
# define DS1337_BIT_A1IE 0x01
+#define DS1340_REG_CONTROL 0x07
+# define DS1340_BIT_OUT 0x80
+# define DS1340_BIT_FT 0x40
+# define DS1340_BIT_CALIB_SIGN 0x20
+# define DS1340_M_CALIBRATION 0x1f
+#define DS1340_REG_FLAG 0x09
+# define DS1340_BIT_OSF 0x80
#define DS1337_REG_STATUS 0x0f
# define DS1337_BIT_OSF 0x80
# define DS1337_BIT_A2I 0x02
@@ -84,21 +92,63 @@ struct ds1307 {
u8 regs[8];
enum ds_type type;
struct i2c_msg msg[2];
- struct i2c_client client;
+ struct i2c_client *client;
+ struct i2c_client dev;
struct rtc_device *rtc;
};
+struct chip_desc {
+ char name[9];
+ unsigned nvram56:1;
+ unsigned alarm:1;
+ enum ds_type type;
+};
+
+static const struct chip_desc chips[] = { {
+ .name = "ds1307",
+ .type = ds_1307,
+ .nvram56 = 1,
+}, {
+ .name = "ds1337",
+ .type = ds_1337,
+ .alarm = 1,
+}, {
+ .name = "ds1338",
+ .type = ds_1338,
+ .nvram56 = 1,
+}, {
+ .name = "ds1339",
+ .type = ds_1339,
+ .alarm = 1,
+}, {
+ .name = "ds1340",
+ .type = ds_1340,
+}, {
+ .name = "m41t00",
+ .type = m41t00,
+}, };
+
+static inline const struct chip_desc *find_chip(const char *s)
+{
+ unsigned i;
+
+ for (i = 0; i < ARRAY_SIZE(chips); i++)
+ if (strnicmp(s, chips[i].name, sizeof chips[i].name) == 0)
+ return &chips[i];
+ return NULL;
+}
static int ds1307_get_time(struct device *dev, struct rtc_time *t)
{
struct ds1307 *ds1307 = dev_get_drvdata(dev);
int tmp;
- /* read the RTC registers all at once */
+ /* read the RTC date and time registers all at once */
ds1307->msg[1].flags = I2C_M_RD;
ds1307->msg[1].len = 7;
- tmp = i2c_transfer(ds1307->client.adapter, ds1307->msg, 2);
+ tmp = i2c_transfer(to_i2c_adapter(ds1307->client->dev.parent),
+ ds1307->msg, 2);
if (tmp != 2) {
dev_err(dev, "%s error %d\n", "read", tmp);
return -EIO;
@@ -129,7 +179,8 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t)
t->tm_hour, t->tm_mday,
t->tm_mon, t->tm_year, t->tm_wday);
- return 0;
+ /* initial clock setting can be undefined */
+ return rtc_valid_tm(t);
}
static int ds1307_set_time(struct device *dev, struct rtc_time *t)
@@ -157,11 +208,18 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
tmp = t->tm_year - 100;
buf[DS1307_REG_YEAR] = BIN2BCD(tmp);
- if (ds1307->type == ds_1337)
+ switch (ds1307->type) {
+ case ds_1337:
+ case ds_1339:
buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
- else if (ds1307->type == ds_1340)
+ break;
+ case ds_1340:
buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
| DS1340_BIT_CENTURY;
+ break;
+ default:
+ break;
+ }
ds1307->msg[1].flags = 0;
ds1307->msg[1].len = 8;
@@ -170,7 +228,8 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
"write", buf[0], buf[1], buf[2], buf[3],
buf[4], buf[5], buf[6]);
- result = i2c_transfer(ds1307->client.adapter, &ds1307->msg[1], 1);
+ result = i2c_transfer(to_i2c_adapter(ds1307->client->dev.parent),
+ &ds1307->msg[1], 1);
if (result != 1) {
dev_err(dev, "%s error %d\n", "write", tmp);
return -EIO;
@@ -185,25 +244,29 @@ static const struct rtc_class_ops ds13xx_rtc_ops = {
static struct i2c_driver ds1307_driver;
-static int __devinit
-ds1307_detect(struct i2c_adapter *adapter, int address, int kind)
+static int __devinit ds1307_probe(struct i2c_client *client)
{
struct ds1307 *ds1307;
int err = -ENODEV;
- struct i2c_client *client;
int tmp;
-
- if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL))) {
- err = -ENOMEM;
- goto exit;
+ const struct chip_desc *chip;
+ struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+
+ chip = find_chip(client->name);
+ if (!chip) {
+ dev_err(&client->dev, "unknown chip type '%s'\n",
+ client->name);
+ return -ENODEV;
}
- client = &ds1307->client;
- client->addr = address;
- client->adapter = adapter;
- client->driver = &ds1307_driver;
- client->flags = 0;
+ if (!i2c_check_functionality(adapter,
+ I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
+ return -EIO;
+
+ if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL)))
+ return -ENOMEM;
+ ds1307->client = client;
i2c_set_clientdata(client, ds1307);
ds1307->msg[0].addr = client->addr;
@@ -216,14 +279,16 @@ ds1307_detect(struct i2c_adapter *adapter, int address, int kind)
ds1307->msg[1].len = sizeof(ds1307->regs);
ds1307->msg[1].buf = ds1307->regs;
- /* HACK: "force" implies "needs ds1337-style-oscillator setup" */
- if (kind >= 0) {
- ds1307->type = ds_1337;
+ ds1307->type = chip->type;
+ switch (ds1307->type) {
+ case ds_1337:
+ case ds_1339:
ds1307->reg_addr = DS1337_REG_CONTROL;
ds1307->msg[1].len = 2;
- tmp = i2c_transfer(client->adapter, ds1307->msg, 2);
+ /* get registers that the "rtc" read below won't read... */
+ tmp = i2c_transfer(adapter, ds1307->msg, 2);
if (tmp != 2) {
pr_debug("read error %d\n", tmp);
err = -EIO;
@@ -233,19 +298,26 @@ ds1307_detect(struct i2c_adapter *adapter, int address, int kind)
ds1307->reg_addr = 0;
ds1307->msg[1].len = sizeof(ds1307->regs);
- /* oscillator is off; need to turn it on */
- if ((ds1307->regs[0] & DS1337_BIT_nEOSC)
- || (ds1307->regs[1] & DS1337_BIT_OSF)) {
- printk(KERN_ERR "no ds1337 oscillator code\n");
- goto exit_free;
+ /* oscillator off? turn it on, so clock can tick. */
+ if (ds1307->regs[0] & DS1337_BIT_nEOSC)
+ i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
+ ds1307->regs[0] & ~DS1337_BIT_nEOSC);
+
+ /* oscillator fault? clear flag, and warn */
+ if (ds1307->regs[1] & DS1337_BIT_OSF) {
+ i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
+ ds1307->regs[1] & ~DS1337_BIT_OSF);
+ dev_warn(&client->dev, "SET TIME!\n");
}
- } else
- ds1307->type = ds_1307;
+ break;
+ default:
+ break;
+ }
read_rtc:
/* read RTC registers */
- tmp = i2c_transfer(client->adapter, ds1307->msg, 2);
+ tmp = i2c_transfer(adapter, ds1307->msg, 2);
if (tmp != 2) {
pr_debug("read error %d\n", tmp);
err = -EIO;
@@ -257,72 +329,80 @@ read_rtc:
* still a few values that are clearly out-of-range.
*/
tmp = ds1307->regs[DS1307_REG_SECS];
- if (tmp & DS1307_BIT_CH) {
- if (ds1307->type && ds1307->type != ds_1307) {
- pr_debug("not a ds1307?\n");
- goto exit_free;
- }
- ds1307->type = ds_1307;
-
- /* this partial initialization should work for ds1307,
- * ds1338, ds1340, st m41t00, and more.
+ switch (ds1307->type) {
+ case ds_1340:
+ /* FIXME read register with DS1340_BIT_OSF, use that to
+ * trigger the "set time" warning (*after* restarting the
+ * oscillator!) instead of this weaker ds1307/m41t00 test.
*/
- dev_warn(&client->dev, "oscillator started; SET TIME!\n");
- i2c_smbus_write_byte_data(client, 0, 0);
- goto read_rtc;
+ case ds_1307:
+ case m41t00:
+ /* clock halted? turn it on, so clock can tick. */
+ if (tmp & DS1307_BIT_CH) {
+ i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
+ dev_warn(&client->dev, "SET TIME!\n");
+ goto read_rtc;
+ }
+ break;
+ case ds_1338:
+ /* clock halted? turn it on, so clock can tick. */
+ if (tmp & DS1307_BIT_CH)
+ i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
+
+ /* oscillator fault? clear flag, and warn */
+ if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
+ i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
+ ds1307->regs[DS1337_REG_CONTROL]
+ & ~DS1338_BIT_OSF);
+ dev_warn(&client->dev, "SET TIME!\n");
+ goto read_rtc;
+ }
+ break;
+ case ds_1337:
+ case ds_1339:
+ break;
}
+
+ tmp = ds1307->regs[DS1307_REG_SECS];
tmp = BCD2BIN(tmp & 0x7f);
if (tmp > 60)
- goto exit_free;
+ goto exit_bad;
tmp = BCD2BIN(ds1307->regs[DS1307_REG_MIN] & 0x7f);
if (tmp > 60)
- goto exit_free;
+ goto exit_bad;
tmp = BCD2BIN(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
if (tmp == 0 || tmp > 31)
- goto exit_free;
+ goto exit_bad;
tmp = BCD2BIN(ds1307->regs[DS1307_REG_MONTH] & 0x1f);
if (tmp == 0 || tmp > 12)
- goto exit_free;
+ goto exit_bad;
- /* force into in 24 hour mode (most chips) or
- * disable century bit (ds1340)
- */
tmp = ds1307->regs[DS1307_REG_HOUR];
- if (tmp & (1 << 6)) {
- if (tmp & (1 << 5))
- tmp = BCD2BIN(tmp & 0x1f) + 12;
- else
- tmp = BCD2BIN(tmp);
- i2c_smbus_write_byte_data(client,
- DS1307_REG_HOUR,
- BIN2BCD(tmp));
- }
-
- /* FIXME chips like 1337 can generate alarm irqs too; those are
- * worth exposing through the API (especially when the irq is
- * wakeup-capable).
- */
-
switch (ds1307->type) {
- case unknown:
- strlcpy(client->name, "unknown", I2C_NAME_SIZE);
- break;
- case ds_1307:
- strlcpy(client->name, "ds1307", I2C_NAME_SIZE);
- break;
- case ds_1337:
- strlcpy(client->name, "ds1337", I2C_NAME_SIZE);
- break;
case ds_1340:
- strlcpy(client->name, "ds1340", I2C_NAME_SIZE);
+ case m41t00:
+ /* NOTE: ignores century bits; fix before deploying
+ * systems that will run through year 2100.
+ */
break;
- }
+ default:
+ if (!(tmp & DS1307_BIT_12HR))
+ break;
- /* Tell the I2C layer a new client has arrived */
- if ((err = i2c_attach_client(client)))
- goto exit_free;
+ /* Be sure we're in 24 hour mode. Multi-master systems
+ * take note...
+ */
+ tmp = BCD2BIN(tmp & 0x1f);
+ if (tmp == 12)
+ tmp = 0;
+ if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
+ tmp += 12;
+ i2c_smbus_write_byte_data(client,
+ DS1307_REG_HOUR,
+ BIN2BCD(tmp));
+ }
ds1307->rtc = rtc_device_register(client->name, &client->dev,
&ds13xx_rtc_ops, THIS_MODULE);
@@ -330,46 +410,40 @@ read_rtc:
err = PTR_ERR(ds1307->rtc);
dev_err(&client->dev,
"unable to register the class device\n");
- goto exit_detach;
+ goto exit_free;
}
return 0;
-exit_detach:
- i2c_detach_client(client);
+exit_bad:
+ dev_dbg(&client->dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
+ "bogus register",
+ ds1307->regs[0], ds1307->regs[1],
+ ds1307->regs[2], ds1307->regs[3],
+ ds1307->regs[4], ds1307->regs[5],
+ ds1307->regs[6]);
+
exit_free:
kfree(ds1307);
-exit:
return err;
}
-static int __devinit
-ds1307_attach_adapter(struct i2c_adapter *adapter)
-{
- if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
- return 0;
- return i2c_probe(adapter, &addr_data, ds1307_detect);
-}
-
-static int __devexit ds1307_detach_client(struct i2c_client *client)
+static int __devexit ds1307_remove(struct i2c_client *client)
{
- int err;
struct ds1307 *ds1307 = i2c_get_clientdata(client);
rtc_device_unregister(ds1307->rtc);
- if ((err = i2c_detach_client(client)))
- return err;
kfree(ds1307);
return 0;
}
static struct i2c_driver ds1307_driver = {
.driver = {
- .name = "ds1307",
+ .name = "rtc-ds1307",
.owner = THIS_MODULE,
},
- .attach_adapter = ds1307_attach_adapter,
- .detach_client = __devexit_p(ds1307_detach_client),
+ .probe = ds1307_probe,
+ .remove = __devexit_p(ds1307_remove),
};
static int __init ds1307_init(void)
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-28 11:11:55 +0300