1 files changed, 187 insertions, 113 deletions

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 3f0f7b8fa81..5158a625671 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)