1 files changed, 94 insertions, 88 deletions

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 62b0763b7b9a..cd188ab72f79 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");