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yaml
---
r: 60850
b: refs/heads/master
c: 045e0e8
h: refs/heads/master
v: v3
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David Brownell authored and Linus Torvalds committed Jul 17, 2007
1 parent b9c432a commit a93da44
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Showing 2 changed files with 125 additions and 53 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 5d91192e667ae34733b9daf6dd5f1d4496d2f441
refs/heads/master: 045e0e85f2f6ee6621d8f7bab3059e9c74076738
176 changes: 124 additions & 52 deletions trunk/drivers/rtc/rtc-ds1307.c
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Original file line number Diff line number Diff line change
Expand Up @@ -24,15 +24,22 @@
* setting the date and time), Linux can ignore the non-clock features.
* That's a natural job for a factory or repair bench.
*
* 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...
*
* 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.)
*/
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...
};

Expand All @@ -56,11 +63,12 @@ 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_STOP 0x20
# define DS1307_BIT_SQWE 0x10
# define DS1307_BIT_RS1 0x02
# define DS1307_BIT_RS0 0x01
Expand All @@ -71,6 +79,13 @@ 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 DS1338_REG_FLAG 0x09
# define DS1338_BIT_OSF 0x80
#define DS1337_REG_STATUS 0x0f
# define DS1337_BIT_OSF 0x80
# define DS1337_BIT_A2I 0x02
Expand All @@ -84,21 +99,63 @@ 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;
Expand Down Expand Up @@ -129,7 +186,8 @@ 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)
Expand Down Expand Up @@ -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;
Expand All @@ -192,18 +251,34 @@ ds1307_detect(struct i2c_adapter *adapter, int address, int kind)
int err = -ENODEV;
struct i2c_client *client;
int tmp;
const struct chip_desc *chip;

if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL))) {
err = -ENOMEM;
goto exit;
}

client = &ds1307->client;
/* REVISIT: pending driver model conversion, set up "client"
* ourselves, and use a hack to determine the RTC type (instead
* of reading the client->name we're given)
*/
client = &ds1307->dev;
client->addr = address;
client->adapter = adapter;
client->driver = &ds1307_driver;
client->flags = 0;

/* HACK: "force" implies "needs ds1337-style-oscillator setup", and
* that's the only kind of chip setup we'll know about. Until the
* driver model conversion, here's where to add any board-specific
* code to say what kind of chip is present...
*/
if (kind >= 0)
chip = find_chip("ds1337");
else
chip = find_chip("ds1307");
strlcpy(client->name, chip->name, I2C_NAME_SIZE);

ds1307->client = client;
i2c_set_clientdata(client, ds1307);

ds1307->msg[0].addr = client->addr;
Expand All @@ -216,14 +291,17 @@ 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 = chip->type;

switch (ds1307->type) {
case ds_1337:
case ds_1339:
ds1307->type = ds_1337;

ds1307->reg_addr = DS1337_REG_CONTROL;
ds1307->msg[1].len = 2;

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;
Expand All @@ -236,16 +314,20 @@ ds1307_detect(struct i2c_adapter *adapter, int address, int kind)
/* 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");
no_osc_start:
printk(KERN_ERR "no %s oscillator code\n",
chip->name);
goto exit_free;
}
} 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;
Expand All @@ -257,20 +339,27 @@ ds1307_detect(struct i2c_adapter *adapter, int address, int kind)
* 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;
switch (ds1307->type) {
case ds_1307:
case ds_1338:
case m41t00:
if (tmp & DS1307_BIT_CH) {
i2c_smbus_write_byte_data(client, 0, 0);
dev_warn(&client->dev,
"oscillator started; SET TIME!\n");
goto read_rtc;
}
ds1307->type = ds_1307;

/* this partial initialization should work for ds1307,
* ds1338, ds1340, st m41t00, and more.
*/
dev_warn(&client->dev, "oscillator started; SET TIME!\n");
i2c_smbus_write_byte_data(client, 0, 0);
goto read_rtc;
break;
case ds_1340:
/* FIXME write code to start the oscillator */
if (tmp & DS1307_BIT_CH)
goto no_osc_start;
break;
default:
break;
}

tmp = ds1307->regs[DS1307_REG_SECS];
tmp = BCD2BIN(tmp & 0x7f);
if (tmp > 60)
goto exit_free;
Expand All @@ -288,6 +377,9 @@ ds1307_detect(struct i2c_adapter *adapter, int address, int kind)

/* force into in 24 hour mode (most chips) or
* disable century bit (ds1340)
*
* REVISIT forcing 24 hour mode can prevent multi-master
* configs from sharing this RTC ... don't do this.
*/
tmp = ds1307->regs[DS1307_REG_HOUR];
if (tmp & (1 << 6)) {
Expand All @@ -300,26 +392,6 @@ ds1307_detect(struct i2c_adapter *adapter, int address, int kind)
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);
break;
}

/* Tell the I2C layer a new client has arrived */
if ((err = i2c_attach_client(client)))
goto exit_free;
Expand Down

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