1 files changed, 124 insertions, 52 deletions

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 3f0f7b8..75e30c6 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -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...
 };
 
@@ -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
@@ -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
@@ -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;
@@ -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)
@@ -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;
@@ -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;
@@ -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;
@@ -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;
@@ -257,20 +339,27 @@ 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;
+	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;
@@ -288,6 +377,9 @@ read_rtc:
 
 	/* 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)) {
@@ -300,26 +392,6 @@ read_rtc:
 				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;