[PATCH] rtc-ds1307 : SMBus compatibility

[PATCH] rtc-ds1307 : SMBus compatibility

[BARRE Sebastien]

[-- Attachment #1: Type: text/plain, Size: 647 bytes --]

This patch change i2c access functions to SMBus access functions
in order to use the ds1307 with SMBus adapter.

Signed-off-by: Sebastien Barre <sbarre@sdelcc.com>

--

The initial patch was based on 2.6.26.5, I've redone it against Linus's current git tree.
Sorry, the patch is attached because my email client replace all the tabs with spaces.

I've tested it with ds1307 chip.
Is somebody can test it on ds1337/ds1338 ?

--
Sébastien Barré
Bureau d'étude - Développement
SDEL Contrôle Commande
D2A - Rue Nungesser et Coli
44860 Saint Aignan de Grand Lieu
FRANCE
Tél : +33(0)2 40 84 50 88
Fax : +33(0)2 40 84 51 10


[-- Attachment #2: patch-rtc-ds1307 --]
[-- Type: application/octet-stream, Size: 7387 bytes --]

--- a/drivers/rtc/rtc-ds1307.c	2008-10-17 14:43:43.000000000 +0200
+++ b/drivers/rtc/rtc-ds1307.c	2008-10-17 15:38:12.000000000 +0200
@@ -86,13 +86,11 @@ enum ds_type {
 
 
 struct ds1307 {
-	u8			reg_addr;
 	u8			regs[11];
 	enum ds_type		type;
 	unsigned long		flags;
 #define HAS_NVRAM	0		/* bit 0 == sysfs file active */
 #define HAS_ALARM	1		/* bit 1 == irq claimed */
-	struct i2c_msg		msg[2];
 	struct i2c_client	*client;
 	struct rtc_device	*rtc;
 	struct work_struct	work;
@@ -204,13 +202,9 @@ static int ds1307_get_time(struct device
 	int		tmp;
 
 	/* read the RTC date and time registers all at once */
-	ds1307->reg_addr = 0;
-	ds1307->msg[1].flags = I2C_M_RD;
-	ds1307->msg[1].len = 7;
-
-	tmp = i2c_transfer(to_i2c_adapter(ds1307->client->dev.parent),
-			ds1307->msg, 2);
-	if (tmp != 2) {
+	tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
+		DS1307_REG_SECS, 7, ds1307->regs);
+	if (tmp != 7) {
 		dev_err(dev, "%s error %d\n", "read", tmp);
 		return -EIO;
 	}
@@ -257,7 +251,6 @@ static int ds1307_set_time(struct device
 		t->tm_hour, t->tm_mday,
 		t->tm_mon, t->tm_year, t->tm_wday);
 
-	*buf++ = 0;		/* first register addr */
 	buf[DS1307_REG_SECS] = BIN2BCD(t->tm_sec);
 	buf[DS1307_REG_MIN] = BIN2BCD(t->tm_min);
 	buf[DS1307_REG_HOUR] = BIN2BCD(t->tm_hour);
@@ -282,18 +275,14 @@ static int ds1307_set_time(struct device
 		break;
 	}
 
-	ds1307->msg[1].flags = 0;
-	ds1307->msg[1].len = 8;
-
 	dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
 		"write", buf[0], buf[1], buf[2], buf[3],
 		buf[4], buf[5], buf[6]);
 
-	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;
+	result = i2c_smbus_write_i2c_block_data(ds1307->client, 0, 7, buf);
+	if (result < 0) {
+		dev_err(dev, "%s error %d\n", "write", result);
+		return result;
 	}
 	return 0;
 }
@@ -308,13 +297,9 @@ static int ds1307_read_alarm(struct devi
 		return -EINVAL;
 
 	/* read all ALARM1, ALARM2, and status registers at once */
-	ds1307->reg_addr = DS1339_REG_ALARM1_SECS;
-	ds1307->msg[1].flags = I2C_M_RD;
-	ds1307->msg[1].len = 9;
-
-	ret = i2c_transfer(to_i2c_adapter(client->dev.parent),
-			ds1307->msg, 2);
-	if (ret != 2) {
+	ret = i2c_smbus_read_i2c_block_data(client,
+			DS1339_REG_ALARM1_SECS, 9, ds1307->regs);
+	if (ret != 9) {
 		dev_err(dev, "%s error %d\n", "alarm read", ret);
 		return -EIO;
 	}
@@ -371,13 +356,9 @@ static int ds1307_set_alarm(struct devic
 		t->enabled, t->pending);
 
 	/* read current status of both alarms and the chip */
-	ds1307->reg_addr = DS1339_REG_ALARM1_SECS;
-	ds1307->msg[1].flags = I2C_M_RD;
-	ds1307->msg[1].len = 9;
-
-	ret = i2c_transfer(to_i2c_adapter(client->dev.parent),
-			ds1307->msg, 2);
-	if (ret != 2) {
+	ret = i2c_smbus_read_i2c_block_data(client,
+			DS1339_REG_ALARM1_SECS, 9, buf);
+	if (ret != 9) {
 		dev_err(dev, "%s error %d\n", "alarm write", ret);
 		return -EIO;
 	}
@@ -392,7 +373,6 @@ static int ds1307_set_alarm(struct devic
 			ds1307->regs[6], control, status);
 
 	/* set ALARM1, using 24 hour and day-of-month modes */
-	*buf++ = DS1339_REG_ALARM1_SECS;	/* first register addr */
 	buf[0] = bin2bcd(t->time.tm_sec);
 	buf[1] = bin2bcd(t->time.tm_min);
 	buf[2] = bin2bcd(t->time.tm_hour);
@@ -411,14 +391,11 @@ static int ds1307_set_alarm(struct devic
 	}
 	buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
 
-	ds1307->msg[1].flags = 0;
-	ds1307->msg[1].len = 10;
-
-	ret = i2c_transfer(to_i2c_adapter(client->dev.parent),
-			&ds1307->msg[1], 1);
-	if (ret != 1) {
+	ret = i2c_smbus_write_i2c_block_data(client,
+			DS1339_REG_ALARM1_SECS, 9, buf);
+	if (ret < 0) {
 		dev_err(dev, "can't set alarm time\n");
-		return -EIO;
+		return ret;
 	}
 
 	return 0;
@@ -490,7 +467,6 @@ ds1307_nvram_read(struct kobject *kobj, 
 {
 	struct i2c_client	*client;
 	struct ds1307		*ds1307;
-	struct i2c_msg		msg[2];
 	int			result;
 
 	client = kobj_to_i2c_client(kobj);
@@ -503,24 +479,10 @@ ds1307_nvram_read(struct kobject *kobj, 
 	if (unlikely(!count))
 		return count;
 
-	msg[0].addr = client->addr;
-	msg[0].flags = 0;
-	msg[0].len = 1;
-	msg[0].buf = buf;
-
-	buf[0] = 8 + off;
-
-	msg[1].addr = client->addr;
-	msg[1].flags = I2C_M_RD;
-	msg[1].len = count;
-	msg[1].buf = buf;
-
-	result = i2c_transfer(to_i2c_adapter(client->dev.parent), msg, 2);
-	if (result != 2) {
+	result = i2c_smbus_read_i2c_block_data(client, 8 + off, count, buf);
+	if (result < 0)
 		dev_err(&client->dev, "%s error %d\n", "nvram read", result);
-		return -EIO;
-	}
-	return count;
+	return result;
 }
 
 static ssize_t
@@ -528,8 +490,7 @@ ds1307_nvram_write(struct kobject *kobj,
 		char *buf, loff_t off, size_t count)
 {
 	struct i2c_client	*client;
-	u8			buffer[NVRAM_SIZE + 1];
-	int			ret;
+	int			result;
 
 	client = kobj_to_i2c_client(kobj);
 
@@ -540,11 +501,12 @@ ds1307_nvram_write(struct kobject *kobj,
 	if (unlikely(!count))
 		return count;
 
-	buffer[0] = 8 + off;
-	memcpy(buffer + 1, buf, count);
-
-	ret = i2c_master_send(client, buffer, count + 1);
-	return (ret < 0) ? ret : (ret - 1);
+	result = i2c_smbus_write_i2c_block_data(client, 8 + off, count, buf);
+	if (result < 0) {
+		dev_err(&client->dev, "%s error %d\n", "nvram write", result);
+		return result;
+	}
+	return count;
 }
 
 static struct bin_attribute nvram = {
@@ -572,9 +534,11 @@ static int __devinit ds1307_probe(struct
 	const struct chip_desc	*chip = &chips[id->driver_data];
 	struct i2c_adapter	*adapter = to_i2c_adapter(client->dev.parent);
 	int			want_irq = false;
+	unsigned char		*buf;
 
 	if (!i2c_check_functionality(adapter,
-			I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
+			I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
+			I2C_FUNC_SMBUS_I2C_BLOCK))
 		return -EIO;
 
 	if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL)))
@@ -582,18 +546,8 @@ static int __devinit ds1307_probe(struct
 
 	ds1307->client = client;
 	i2c_set_clientdata(client, ds1307);
-
-	ds1307->msg[0].addr = client->addr;
-	ds1307->msg[0].flags = 0;
-	ds1307->msg[0].len = 1;
-	ds1307->msg[0].buf = &ds1307->reg_addr;
-
-	ds1307->msg[1].addr = client->addr;
-	ds1307->msg[1].flags = I2C_M_RD;
-	ds1307->msg[1].len = sizeof(ds1307->regs);
-	ds1307->msg[1].buf = ds1307->regs;
-
 	ds1307->type = id->driver_data;
+	buf = ds1307->regs;
 
 	switch (ds1307->type) {
 	case ds_1337:
@@ -603,21 +557,15 @@ static int __devinit ds1307_probe(struct
 			INIT_WORK(&ds1307->work, ds1307_work);
 			want_irq = true;
 		}
-
-		ds1307->reg_addr = DS1337_REG_CONTROL;
-		ds1307->msg[1].len = 2;
-
 		/* get registers that the "rtc" read below won't read... */
-		tmp = i2c_transfer(adapter, ds1307->msg, 2);
+		tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
+				DS1337_REG_CONTROL, 2, buf);
 		if (tmp != 2) {
 			pr_debug("read error %d\n", tmp);
 			err = -EIO;
 			goto exit_free;
 		}
 
-		ds1307->reg_addr = 0;
-		ds1307->msg[1].len = sizeof(ds1307->regs);
-
 		/* oscillator off?  turn it on, so clock can tick. */
 		if (ds1307->regs[0] & DS1337_BIT_nEOSC)
 			ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
@@ -648,9 +596,8 @@ static int __devinit ds1307_probe(struct
 
 read_rtc:
 	/* read RTC registers */
-
-	tmp = i2c_transfer(adapter, ds1307->msg, 2);
-	if (tmp != 2) {
+	tmp = i2c_smbus_read_i2c_block_data(ds1307->client, 0, 8, buf);
+	if (tmp != 8) {
 		pr_debug("read error %d\n", tmp);
 		err = -EIO;
 		goto exit_free;

[-- Attachment #3: Type: text/plain, Size: 157 bytes --]

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Re: [rtc-linux] [i2c] [PATCH] rtc-ds1307 : SMBus compatibility

[Alessandro Zummo]

On Fri, 17 Oct 2008 17:11:27 +0200
BARRE Sebastien <sbarre@sdelcc.com> wrote:

> I've tested it with ds1307 chip.
> Is somebody can test it on ds1337/ds1338 ?

 Given the amount of changes I need some Tested-bys
 for the patch to go thru.

-- 

 Best regards,

 Alessandro Zummo,
  Tower Technologies - Torino, Italy

  http://www.towertech.it

Re: [rtc-linux] [i2c] [PATCH] rtc-ds1307 : SMBus compatibility

[David Brownell]

On Tuesday 21 October 2008, Alessandro Zummo wrote:
> > I've tested it with ds1307 chip.
> > Is somebody can test it on ds1337/ds1338 ?
> 
>  Given the amount of changes I need some Tested-bys
>  for the patch to go thru.

I tested these changes on my trusty ds1307 system using i2c-gpio
(vs a "real SMBus controller") and it works just fine.

Of the nine changed I/O calls, testing with the ds1307 covers
all but the three supporting the new alarm calls.  Given that
those alarm changes are "obvious", I actually don't have any
qualms signing off on these changes ... though it would of
course be good to have Rodolfo re-test his alarm code.  (It's
freshly merged in any case, so it merits testing just in case
a problem snuck in!)

- Dave