Patchwork Re: [PATCH 2.6.39-rc7] RTC: rtc-ds1307 EEPROM support for ds1388 chip

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Submitter Austin Boyle
Date June 14, 2011, 4:14 a.m.
Message ID <1308024897.2992.39.camel@pc786-ubu.gnet.global.vpn>
Download mbox | patch
Permalink /patch/100265/
State New
Headers show

Comments

Austin Boyle - June 14, 2011, 4:14 a.m.
On Mon, 2011-05-23 at 17:18 +1200, Austin Boyle wrote:
> This is my patch which extends the NVRAM access functions in the DS1307
> driver to support the 512 bytes of EEPROM on the DS1388 chip. Could you
> please review the patch? If there are any problems with the way I have
> implemented this or suggested improvements I will gladly modify. Thanks!

This is an updated version of the patch which prints the correct NVRAM
size at init. Could someone please give me some feedback?

[PATCH 3.0-rc3] RTC: rtc-ds1307: EEPROM support for ds1388 chip

This patch adds support for different sized NVRAM, such as
the 512 bytes of EEPROM on the DS1388 chip.

Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Austin Boyle <austin.boyle@aviatnet.com>
---
 	if (result < 0)
 		dev_err(&client->dev, "%s error %d\n", "nvram read", result);
 	return result;
@@ -565,18 +591,40 @@ ds1307_nvram_write(struct file *filp, st
 	struct i2c_client	*client;
 	struct ds1307		*ds1307;
 	int			result;
+	unsigned int		addr = 0;
 
 	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);
+	if (ds1307->nvram_offset < 0xff) {	/* ds1307, ds1338 */
+		result = ds1307->write_block_data(client, ds1307->nvram_offset + off,
count, buf);
+	} else	{	/* ds1388 */
+		if ((off <= 0x00ff) && ((off + count) > 0x00ff))	{  /* read spans two
blocks */
+			client = ds1307->client[1];		/* first block */
+			addr = (unsigned int)off;
+			result = ds1307->write_block_data(client, addr, (0x100-addr), buf);
+			client = ds1307->client[2];		/* second block */
+			result = ds1307->write_block_data(client, 0x00, (addr+count-0x100),
(buf+0x100-addr));
+
+		} else { /* Device address/offset translation */
+			dev_dbg(&client->dev, "Write spans one block\n");
+			if (off <= 0x00ff)	{
+				client = ds1307->client[1];
+				addr = (unsigned int)off;
+			} else if (off <= 0x0200)	{
+				client = ds1307->client[2];
+				addr = (unsigned int)off - 0x100;
+			}
+			result = ds1307->write_block_data(client, addr, count, buf);
+		}
+	}
 	if (result < 0) {
 		dev_err(&client->dev, "%s error %d\n", "nvram write", result);
 		return result;
@@ -592,7 +640,6 @@ static struct bin_attribute nvram = {
 
 	.read	= ds1307_nvram_read,
 	.write	= ds1307_nvram_write,
-	.size	= NVRAM_SIZE,
 };
 
 /*----------------------------------------------------------------------*/
@@ -605,6 +652,7 @@ static int __devinit ds1307_probe(struct
 	struct ds1307		*ds1307;
 	int			err = -ENODEV;
 	int			tmp;
+	int			i;
 	const struct chip_desc	*chip = &chips[id->driver_data];
 	struct i2c_adapter	*adapter = to_i2c_adapter(client->dev.parent);
 	int			want_irq = false;
@@ -624,9 +672,10 @@ static int __devinit ds1307_probe(struct
 
 	i2c_set_clientdata(client, ds1307);
 
-	ds1307->client	= client;
+	ds1307->client[0] = client;
 	ds1307->type	= id->driver_data;
 	ds1307->offset	= 0;
+	ds1307->num_addrs = 1;
 
 	buf = ds1307->regs;
 	if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
@@ -642,12 +691,12 @@ static int __devinit ds1307_probe(struct
 	case ds_1339:
 	case ds_3231:
 		/* has IRQ? */
-		if (ds1307->client->irq > 0 && chip->alarm) {
+		if (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,
+		tmp = ds1307->read_block_data(client,
 				DS1337_REG_CONTROL, 2, buf);
 		if (tmp != 2) {
 			pr_debug("read error %d\n", tmp);
@@ -681,7 +730,7 @@ static int __devinit ds1307_probe(struct
 		break;
 
 	case rx_8025:
-		tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
+		tmp = i2c_smbus_read_i2c_block_data(client,
 				RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
 		if (tmp != 2) {
 			pr_debug("read error %d\n", tmp);
@@ -747,6 +796,14 @@ static int __devinit ds1307_probe(struct
 		break;
 	case ds_1388:
 		ds1307->offset = 1; /* Seconds starts at 1 */
+		ds1307->num_addrs = 3;	/* uses 3 I2C addrs */
+		ds1307->nvram_size = 512; /* 512 bytes EEPROM */
+		ds1307->nvram_offset = 0xff;
+		break;
+	case ds_1307:
+	case ds_1338:
+		ds1307->nvram_size = 56; /* 56 bytes NVRAM */
+		ds1307->nvram_offset = 8;
 		break;
 	default:
 		break;
@@ -754,7 +811,7 @@ static int __devinit ds1307_probe(struct
 
 read_rtc:
 	/* read RTC registers */
-	tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
+	tmp = ds1307->read_block_data(client, ds1307->offset, 8, buf);
 	if (tmp != 8) {
 		pr_debug("read error %d\n", tmp);
 		err = -EIO;
@@ -866,16 +923,35 @@ read_rtc:
 		dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
 	}
 
-	if (chip->nvram56) {
+	if (chip->nvram) {
+		nvram.size = ds1307->nvram_size;
 		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");
+			dev_info(&client->dev, "%d bytes nvram\n", nvram.size);
+		}
+	}
+
+	/* use dummy devices for multiple address chips */
+	for (i = 1; i < ds1307->num_addrs; i++) {
+		ds1307->client[i] = i2c_new_dummy(client->adapter, client->addr + i);
+		if (!ds1307->client[i]) {
+			dev_err(&client->dev, "address 0x%02x unavailable\n",
+					client->addr + i);
+			err = -EADDRINUSE;
+			goto err_clients;
 		}
+		i2c_set_clientdata(ds1307->client[i], ds1307);
 	}
 
 	return 0;
 
+err_clients:
+	for (i = 1; i < ds1307->num_addrs; i++)	{
+		if (ds1307->client[i])	{
+			i2c_unregister_device(ds1307->client[i]);
+		}
+	}
 exit_irq:
 	rtc_device_unregister(ds1307->rtc);
 exit_free:
Austin Boyle - July 17, 2011, 11:32 p.m.
Hi Joakim,

I see that you were responsible for adding support for the ds1388 RTC in
the ds1307 driver. Thank you for your work, I am using the driver for
this IC myself. I have been trying to submit a patch to add support for
the 512 bytes of EEPROM available on the ds1388 but have not received
any responses. Would you be willing to review my patch? I can send
through another version applied to the very latest kernel. Are the RTC
patches all submitted through Alessandro Zummo who is listed as the
maintainer or should they be sent directly to Linus?

Kind Regards,
Austin Boyle.

On Tue, 2011-06-14 at 16:15 +1200, Austin Boyle wrote:
> On Mon, 2011-05-23 at 17:18 +1200, Austin Boyle wrote:
> > This is my patch which extends the NVRAM access functions in the DS1307
> > driver to support the 512 bytes of EEPROM on the DS1388 chip. Could you
> > please review the patch? If there are any problems with the way I have
> > implemented this or suggested improvements I will gladly modify. Thanks!
> 
> This is an updated version of the patch which prints the correct NVRAM
> size at init. Could someone please give me some feedback?
> 
> [PATCH 3.0-rc3] RTC: rtc-ds1307: EEPROM support for ds1388 chip
> 
> This patch adds support for different sized NVRAM, such as
> the 512 bytes of EEPROM on the DS1388 chip.
> 
> Cc: Alessandro Zummo <a.zummo@towertech.it>
> Signed-off-by: Austin Boyle <austin.boyle@aviatnet.com>
> ---
> diff -upNr a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
> --- a/drivers/rtc/rtc-ds1307.c	2011-06-14 15:56:45.221497487 +1200
> +++ b/drivers/rtc/rtc-ds1307.c	2011-06-14 15:57:28.803510835 +1200
> @@ -95,15 +95,19 @@ enum ds_type {
>  #	define RX8025_BIT_VDET		0x40
>  #	define RX8025_BIT_XST		0x20
>  
> +#define DS1307_MAX_NUM_ADDRS	3
>  
>  struct ds1307 {
>  	u8			offset; /* register's offset */
> +	u16			nvram_size;
> +	u16			nvram_offset;
> +	u8			num_addrs;
>  	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_client	*client;
> +	struct i2c_client	*client[DS1307_MAX_NUM_ADDRS];
>  	struct rtc_device	*rtc;
>  	struct work_struct	work;
>  	s32 (*read_block_data)(const struct i2c_client *client, u8 command,
> @@ -113,23 +117,26 @@ struct ds1307 {
>  };
>  
>  struct chip_desc {
> -	unsigned		nvram56:1;
> +	unsigned		nvram:1;
>  	unsigned		alarm:1;
>  };
>  
>  static const struct chip_desc chips[] = {
>  [ds_1307] = {
> -	.nvram56	= 1,
> +	.nvram		= 1,
>  },
>  [ds_1337] = {
>  	.alarm		= 1,
>  },
>  [ds_1338] = {
> -	.nvram56	= 1,
> +	.nvram		= 1,
>  },
>  [ds_1339] = {
>  	.alarm		= 1,
>  },
> +[ds_1388] = {
> +	.nvram		= 1,
> +},
>  [ds_1340] = {
>  },
>  [ds_3231] = {
> @@ -248,7 +255,7 @@ static void ds1307_work(struct work_stru
>  	int			stat, control;
>  
>  	ds1307 = container_of(work, struct ds1307, work);
> -	client = ds1307->client;
> +	client = ds1307->client[0];
>  	lock = &ds1307->rtc->ops_lock;
>  
>  	mutex_lock(lock);
> @@ -294,7 +301,7 @@ static int ds1307_get_time(struct device
>  	int		tmp;
>  
>  	/* read the RTC date and time registers all at once */
> -	tmp = ds1307->read_block_data(ds1307->client,
> +	tmp = ds1307->read_block_data(ds1307->client[0],
>  		ds1307->offset, 7, ds1307->regs);
>  	if (tmp != 7) {
>  		dev_err(dev, "%s error %d\n", "read", tmp);
> @@ -372,7 +379,7 @@ static int ds1307_set_time(struct device
>  		"write", buf[0], buf[1], buf[2], buf[3],
>  		buf[4], buf[5], buf[6]);
>  
> -	result = ds1307->write_block_data(ds1307->client,
> +	result = ds1307->write_block_data(ds1307->client[0],
>  		ds1307->offset, 7, buf);
>  	if (result < 0) {
>  		dev_err(dev, "%s error %d\n", "write", result);
> @@ -530,8 +537,6 @@ static const struct rtc_class_ops ds13xx
>  
>  /*----------------------------------------------------------------------*/
>  
> -#define NVRAM_SIZE	56
> -
>  static ssize_t
>  ds1307_nvram_read(struct file *filp, struct kobject *kobj,
>  		struct bin_attribute *attr,
> @@ -540,18 +545,39 @@ ds1307_nvram_read(struct file *filp, str
>  	struct i2c_client	*client;
>  	struct ds1307		*ds1307;
>  	int			result;
> +	unsigned int		addr = 0;
>  
>  	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);
> +	if (ds1307->nvram_offset < 0xff) {	/* ds1307, ds1338 */
> +		result = ds1307->read_block_data(client, ds1307->nvram_offset + off,
> count, buf);
> +	} else	{	/* ds1388 */
> +		if ((off <= 0x00ff) && (off + count > 0x00ff))	{	/* read spans two
> blocks */
> +			client = ds1307->client[1];		/* first block */
> +			addr = (unsigned int)off;
> +			result = ds1307->read_block_data(client, addr, (0x100-addr), buf);
> +			client = ds1307->client[2];		/* second block */
> +			result += ds1307->read_block_data(client, 0x00, (count+addr-0x100),
> (buf+0x100-addr));
> +
> +		} else { 	/* read spans one blocks */
> +			if (off <= 0x00ff)	{
> +				client = ds1307->client[1];
> +				addr = (unsigned int)off;
> +			} else if (off <= 0x0200)	{
> +				client = ds1307->client[2];
> +				addr = (unsigned int)off - 0x100;
> +			}
> +			result = ds1307->read_block_data(client, addr, count, buf);
> +		}
> +	}
>  	if (result < 0)
>  		dev_err(&client->dev, "%s error %d\n", "nvram read", result);
>  	return result;
> @@ -565,18 +591,40 @@ ds1307_nvram_write(struct file *filp, st
>  	struct i2c_client	*client;
>  	struct ds1307		*ds1307;
>  	int			result;
> +	unsigned int		addr = 0;
>  
>  	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);
> +	if (ds1307->nvram_offset < 0xff) {	/* ds1307, ds1338 */
> +		result = ds1307->write_block_data(client, ds1307->nvram_offset + off,
> count, buf);
> +	} else	{	/* ds1388 */
> +		if ((off <= 0x00ff) && ((off + count) > 0x00ff))	{  /* read spans two
> blocks */
> +			client = ds1307->client[1];		/* first block */
> +			addr = (unsigned int)off;
> +			result = ds1307->write_block_data(client, addr, (0x100-addr), buf);
> +			client = ds1307->client[2];		/* second block */
> +			result = ds1307->write_block_data(client, 0x00, (addr+count-0x100),
> (buf+0x100-addr));
> +
> +		} else { /* Device address/offset translation */
> +			dev_dbg(&client->dev, "Write spans one block\n");
> +			if (off <= 0x00ff)	{
> +				client = ds1307->client[1];
> +				addr = (unsigned int)off;
> +			} else if (off <= 0x0200)	{
> +				client = ds1307->client[2];
> +				addr = (unsigned int)off - 0x100;
> +			}
> +			result = ds1307->write_block_data(client, addr, count, buf);
> +		}
> +	}
>  	if (result < 0) {
>  		dev_err(&client->dev, "%s error %d\n", "nvram write", result);
>  		return result;
> @@ -592,7 +640,6 @@ static struct bin_attribute nvram = {
>  
>  	.read	= ds1307_nvram_read,
>  	.write	= ds1307_nvram_write,
> -	.size	= NVRAM_SIZE,
>  };
>  
>  /*----------------------------------------------------------------------*/
> @@ -605,6 +652,7 @@ static int __devinit ds1307_probe(struct
>  	struct ds1307		*ds1307;
>  	int			err = -ENODEV;
>  	int			tmp;
> +	int			i;
>  	const struct chip_desc	*chip = &chips[id->driver_data];
>  	struct i2c_adapter	*adapter = to_i2c_adapter(client->dev.parent);
>  	int			want_irq = false;
> @@ -624,9 +672,10 @@ static int __devinit ds1307_probe(struct
>  
>  	i2c_set_clientdata(client, ds1307);
>  
> -	ds1307->client	= client;
> +	ds1307->client[0] = client;
>  	ds1307->type	= id->driver_data;
>  	ds1307->offset	= 0;
> +	ds1307->num_addrs = 1;
>  
>  	buf = ds1307->regs;
>  	if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
> @@ -642,12 +691,12 @@ static int __devinit ds1307_probe(struct
>  	case ds_1339:
>  	case ds_3231:
>  		/* has IRQ? */
> -		if (ds1307->client->irq > 0 && chip->alarm) {
> +		if (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,
> +		tmp = ds1307->read_block_data(client,
>  				DS1337_REG_CONTROL, 2, buf);
>  		if (tmp != 2) {
>  			pr_debug("read error %d\n", tmp);
> @@ -681,7 +730,7 @@ static int __devinit ds1307_probe(struct
>  		break;
>  
>  	case rx_8025:
> -		tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
> +		tmp = i2c_smbus_read_i2c_block_data(client,
>  				RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
>  		if (tmp != 2) {
>  			pr_debug("read error %d\n", tmp);
> @@ -747,6 +796,14 @@ static int __devinit ds1307_probe(struct
>  		break;
>  	case ds_1388:
>  		ds1307->offset = 1; /* Seconds starts at 1 */
> +		ds1307->num_addrs = 3;	/* uses 3 I2C addrs */
> +		ds1307->nvram_size = 512; /* 512 bytes EEPROM */
> +		ds1307->nvram_offset = 0xff;
> +		break;
> +	case ds_1307:
> +	case ds_1338:
> +		ds1307->nvram_size = 56; /* 56 bytes NVRAM */
> +		ds1307->nvram_offset = 8;
>  		break;
>  	default:
>  		break;
> @@ -754,7 +811,7 @@ static int __devinit ds1307_probe(struct
>  
>  read_rtc:
>  	/* read RTC registers */
> -	tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
> +	tmp = ds1307->read_block_data(client, ds1307->offset, 8, buf);
>  	if (tmp != 8) {
>  		pr_debug("read error %d\n", tmp);
>  		err = -EIO;
> @@ -866,16 +923,35 @@ read_rtc:
>  		dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
>  	}
>  
> -	if (chip->nvram56) {
> +	if (chip->nvram) {
> +		nvram.size = ds1307->nvram_size;
>  		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");
> +			dev_info(&client->dev, "%d bytes nvram\n", nvram.size);
> +		}
> +	}
> +
> +	/* use dummy devices for multiple address chips */
> +	for (i = 1; i < ds1307->num_addrs; i++) {
> +		ds1307->client[i] = i2c_new_dummy(client->adapter, client->addr + i);
> +		if (!ds1307->client[i]) {
> +			dev_err(&client->dev, "address 0x%02x unavailable\n",
> +					client->addr + i);
> +			err = -EADDRINUSE;
> +			goto err_clients;
>  		}
> +		i2c_set_clientdata(ds1307->client[i], ds1307);
>  	}
>  
>  	return 0;
>  
> +err_clients:
> +	for (i = 1; i < ds1307->num_addrs; i++)	{
> +		if (ds1307->client[i])	{
> +			i2c_unregister_device(ds1307->client[i]);
> +		}
> +	}
>  exit_irq:
>  	rtc_device_unregister(ds1307->rtc);
>  exit_free:
Joakim Tjernlund - July 22, 2011, 10:19 a.m.
Austin Boyle <Austin.Boyle@aviatnet.com> wrote on 2011/07/18 01:32:25:
>
> Hi Joakim,
>
> I see that you were responsible for adding support for the ds1388 RTC in
> the ds1307 driver. Thank you for your work, I am using the driver for
> this IC myself. I have been trying to submit a patch to add support for
> the 512 bytes of EEPROM available on the ds1388 but have not received
> any responses. Would you be willing to review my patch? I can send
> through another version applied to the very latest kernel. Are the RTC
> patches all submitted through Alessandro Zummo who is listed as the
> maintainer or should they be sent directly to Linus?

Hi Austin,

I am on vacation and won't be able to review your patch for a long time. I think
Andrew Morton is your best bet if Alessandro is unavailable though.

      Jocke

>
> Kind Regards,
> Austin Boyle.
>
> On Tue, 2011-06-14 at 16:15 +1200, Austin Boyle wrote:
> > On Mon, 2011-05-23 at 17:18 +1200, Austin Boyle wrote:
> > > This is my patch which extends the NVRAM access functions in the DS1307
> > > driver to support the 512 bytes of EEPROM on the DS1388 chip. Could you
> > > please review the patch? If there are any problems with the way I have
> > > implemented this or suggested improvements I will gladly modify. Thanks!
> >
> > This is an updated version of the patch which prints the correct NVRAM
> > size at init. Could someone please give me some feedback?
> >
> > [PATCH 3.0-rc3] RTC: rtc-ds1307: EEPROM support for ds1388 chip
> >
> > This patch adds support for different sized NVRAM, such as
> > the 512 bytes of EEPROM on the DS1388 chip.
> >
> > Cc: Alessandro Zummo <a.zummo@towertech.it>
> > Signed-off-by: Austin Boyle <austin.boyle@aviatnet.com>
> > ---
> > diff -upNr a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
> > --- a/drivers/rtc/rtc-ds1307.c   2011-06-14 15:56:45.221497487 +1200
> > +++ b/drivers/rtc/rtc-ds1307.c   2011-06-14 15:57:28.803510835 +1200
> > @@ -95,15 +95,19 @@ enum ds_type {
> >  #   define RX8025_BIT_VDET      0x40
> >  #   define RX8025_BIT_XST      0x20
> >
> > +#define DS1307_MAX_NUM_ADDRS   3
> >
> >  struct ds1307 {
> >     u8         offset; /* register's offset */
> > +   u16         nvram_size;
> > +   u16         nvram_offset;
> > +   u8         num_addrs;
> >     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_client   *client;
> > +   struct i2c_client   *client[DS1307_MAX_NUM_ADDRS];
> >     struct rtc_device   *rtc;
> >     struct work_struct   work;
> >     s32 (*read_block_data)(const struct i2c_client *client, u8 command,
> > @@ -113,23 +117,26 @@ struct ds1307 {
> >  };
> >
> >  struct chip_desc {
> > -   unsigned      nvram56:1;
> > +   unsigned      nvram:1;
> >     unsigned      alarm:1;
> >  };
> >
> >  static const struct chip_desc chips[] = {
> >  [ds_1307] = {
> > -   .nvram56   = 1,
> > +   .nvram      = 1,
> >  },
> >  [ds_1337] = {
> >     .alarm      = 1,
> >  },
> >  [ds_1338] = {
> > -   .nvram56   = 1,
> > +   .nvram      = 1,
> >  },
> >  [ds_1339] = {
> >     .alarm      = 1,
> >  },
> > +[ds_1388] = {
> > +   .nvram      = 1,
> > +},
> >  [ds_1340] = {
> >  },
> >  [ds_3231] = {
> > @@ -248,7 +255,7 @@ static void ds1307_work(struct work_stru
> >     int         stat, control;
> >
> >     ds1307 = container_of(work, struct ds1307, work);
> > -   client = ds1307->client;
> > +   client = ds1307->client[0];
> >     lock = &ds1307->rtc->ops_lock;
> >
> >     mutex_lock(lock);
> > @@ -294,7 +301,7 @@ static int ds1307_get_time(struct device
> >     int      tmp;
> >
> >     /* read the RTC date and time registers all at once */
> > -   tmp = ds1307->read_block_data(ds1307->client,
> > +   tmp = ds1307->read_block_data(ds1307->client[0],
> >        ds1307->offset, 7, ds1307->regs);
> >     if (tmp != 7) {
> >        dev_err(dev, "%s error %d\n", "read", tmp);
> > @@ -372,7 +379,7 @@ static int ds1307_set_time(struct device
> >        "write", buf[0], buf[1], buf[2], buf[3],
> >        buf[4], buf[5], buf[6]);
> >
> > -   result = ds1307->write_block_data(ds1307->client,
> > +   result = ds1307->write_block_data(ds1307->client[0],
> >        ds1307->offset, 7, buf);
> >     if (result < 0) {
> >        dev_err(dev, "%s error %d\n", "write", result);
> > @@ -530,8 +537,6 @@ static const struct rtc_class_ops ds13xx
> >
> >  /*----------------------------------------------------------------------*/
> >
> > -#define NVRAM_SIZE   56
> > -
> >  static ssize_t
> >  ds1307_nvram_read(struct file *filp, struct kobject *kobj,
> >        struct bin_attribute *attr,
> > @@ -540,18 +545,39 @@ ds1307_nvram_read(struct file *filp, str
> >     struct i2c_client   *client;
> >     struct ds1307      *ds1307;
> >     int         result;
> > +   unsigned int      addr = 0;
> >
> >     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);
> > +   if (ds1307->nvram_offset < 0xff) {   /* ds1307, ds1338 */
> > +      result = ds1307->read_block_data(client, ds1307->nvram_offset + off,
> > count, buf);
> > +   } else   {   /* ds1388 */
> > +      if ((off <= 0x00ff) && (off + count > 0x00ff))   {   /* read spans two
> > blocks */
> > +         client = ds1307->client[1];      /* first block */
> > +         addr = (unsigned int)off;
> > +         result = ds1307->read_block_data(client, addr, (0x100-addr), buf);
> > +         client = ds1307->client[2];      /* second block */
> > +         result += ds1307->read_block_data(client, 0x00, (count+addr-0x100),
> > (buf+0x100-addr));
> > +
> > +      } else {    /* read spans one blocks */
> > +         if (off <= 0x00ff)   {
> > +            client = ds1307->client[1];
> > +            addr = (unsigned int)off;
> > +         } else if (off <= 0x0200)   {
> > +            client = ds1307->client[2];
> > +            addr = (unsigned int)off - 0x100;
> > +         }
> > +         result = ds1307->read_block_data(client, addr, count, buf);
> > +      }
> > +   }
> >     if (result < 0)
> >        dev_err(&client->dev, "%s error %d\n", "nvram read", result);
> >     return result;
> > @@ -565,18 +591,40 @@ ds1307_nvram_write(struct file *filp, st
> >     struct i2c_client   *client;
> >     struct ds1307      *ds1307;
> >     int         result;
> > +   unsigned int      addr = 0;
> >
> >     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);
> > +   if (ds1307->nvram_offset < 0xff) {   /* ds1307, ds1338 */
> > +      result = ds1307->write_block_data(client, ds1307->nvram_offset + off,
> > count, buf);
> > +   } else   {   /* ds1388 */
> > +      if ((off <= 0x00ff) && ((off + count) > 0x00ff))   {  /* read spans two
> > blocks */
> > +         client = ds1307->client[1];      /* first block */
> > +         addr = (unsigned int)off;
> > +         result = ds1307->write_block_data(client, addr, (0x100-addr), buf);
> > +         client = ds1307->client[2];      /* second block */
> > +         result = ds1307->write_block_data(client, 0x00, (addr+count-0x100),
> > (buf+0x100-addr));
> > +
> > +      } else { /* Device address/offset translation */
> > +         dev_dbg(&client->dev, "Write spans one block\n");
> > +         if (off <= 0x00ff)   {
> > +            client = ds1307->client[1];
> > +            addr = (unsigned int)off;
> > +         } else if (off <= 0x0200)   {
> > +            client = ds1307->client[2];
> > +            addr = (unsigned int)off - 0x100;
> > +         }
> > +         result = ds1307->write_block_data(client, addr, count, buf);
> > +      }
> > +   }
> >     if (result < 0) {
> >        dev_err(&client->dev, "%s error %d\n", "nvram write", result);
> >        return result;
> > @@ -592,7 +640,6 @@ static struct bin_attribute nvram = {
> >
> >     .read   = ds1307_nvram_read,
> >     .write   = ds1307_nvram_write,
> > -   .size   = NVRAM_SIZE,
> >  };
> >
> >  /*----------------------------------------------------------------------*/
> > @@ -605,6 +652,7 @@ static int __devinit ds1307_probe(struct
> >     struct ds1307      *ds1307;
> >     int         err = -ENODEV;
> >     int         tmp;
> > +   int         i;
> >     const struct chip_desc   *chip = &chips[id->driver_data];
> >     struct i2c_adapter   *adapter = to_i2c_adapter(client->dev.parent);
> >     int         want_irq = false;
> > @@ -624,9 +672,10 @@ static int __devinit ds1307_probe(struct
> >
> >     i2c_set_clientdata(client, ds1307);
> >
> > -   ds1307->client   = client;
> > +   ds1307->client[0] = client;
> >     ds1307->type   = id->driver_data;
> >     ds1307->offset   = 0;
> > +   ds1307->num_addrs = 1;
> >
> >     buf = ds1307->regs;
> >     if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
> > @@ -642,12 +691,12 @@ static int __devinit ds1307_probe(struct
> >     case ds_1339:
> >     case ds_3231:
> >        /* has IRQ? */
> > -      if (ds1307->client->irq > 0 && chip->alarm) {
> > +      if (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,
> > +      tmp = ds1307->read_block_data(client,
> >              DS1337_REG_CONTROL, 2, buf);
> >        if (tmp != 2) {
> >           pr_debug("read error %d\n", tmp);
> > @@ -681,7 +730,7 @@ static int __devinit ds1307_probe(struct
> >        break;
> >
> >     case rx_8025:
> > -      tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
> > +      tmp = i2c_smbus_read_i2c_block_data(client,
> >              RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
> >        if (tmp != 2) {
> >           pr_debug("read error %d\n", tmp);
> > @@ -747,6 +796,14 @@ static int __devinit ds1307_probe(struct
> >        break;
> >     case ds_1388:
> >        ds1307->offset = 1; /* Seconds starts at 1 */
> > +      ds1307->num_addrs = 3;   /* uses 3 I2C addrs */
> > +      ds1307->nvram_size = 512; /* 512 bytes EEPROM */
> > +      ds1307->nvram_offset = 0xff;
> > +      break;
> > +   case ds_1307:
> > +   case ds_1338:
> > +      ds1307->nvram_size = 56; /* 56 bytes NVRAM */
> > +      ds1307->nvram_offset = 8;
> >        break;
> >     default:
> >        break;
> > @@ -754,7 +811,7 @@ static int __devinit ds1307_probe(struct
> >
> >  read_rtc:
> >     /* read RTC registers */
> > -   tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
> > +   tmp = ds1307->read_block_data(client, ds1307->offset, 8, buf);
> >     if (tmp != 8) {
> >        pr_debug("read error %d\n", tmp);
> >        err = -EIO;
> > @@ -866,16 +923,35 @@ read_rtc:
> >        dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
> >     }
> >
> > -   if (chip->nvram56) {
> > +   if (chip->nvram) {
> > +      nvram.size = ds1307->nvram_size;
> >        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");
> > +         dev_info(&client->dev, "%d bytes nvram\n", nvram.size);
> > +      }
> > +   }
> > +
> > +   /* use dummy devices for multiple address chips */
> > +   for (i = 1; i < ds1307->num_addrs; i++) {
> > +      ds1307->client[i] = i2c_new_dummy(client->adapter, client->addr + i);
> > +      if (!ds1307->client[i]) {
> > +         dev_err(&client->dev, "address 0x%02x unavailable\n",
> > +               client->addr + i);
> > +         err = -EADDRINUSE;
> > +         goto err_clients;
> >        }
> > +      i2c_set_clientdata(ds1307->client[i], ds1307);
> >     }
> >
> >     return 0;
> >
> > +err_clients:
> > +   for (i = 1; i < ds1307->num_addrs; i++)   {
> > +      if (ds1307->client[i])   {
> > +         i2c_unregister_device(ds1307->client[i]);
> > +      }
> > +   }
> >  exit_irq:
> >     rtc_device_unregister(ds1307->rtc);
> >  exit_free:
>
>
Andrew Morton - July 22, 2011, 9:54 p.m.
On Tue, 14 Jun 2011 16:14:57 +1200
Austin Boyle <Austin.Boyle@aviatnet.com> wrote:

> On Mon, 2011-05-23 at 17:18 +1200, Austin Boyle wrote:
> > This is my patch which extends the NVRAM access functions in the DS1307
> > driver to support the 512 bytes of EEPROM on the DS1388 chip. Could you
> > please review the patch? If there are any problems with the way I have
> > implemented this or suggested improvements I will gladly modify. Thanks!
> 
> This is an updated version of the patch which prints the correct NVRAM
> size at init. Could someone please give me some feedback?
> 
> [PATCH 3.0-rc3] RTC: rtc-ds1307: EEPROM support for ds1388 chip
> 
> This patch adds support for different sized NVRAM, such as
> the 512 bytes of EEPROM on the DS1388 chip.

The patch is wordwrapped - please fix your email client.

The patch makes rather a mess of a decent-looking driver.  Please use
scripts/checkpatch.pl and review its report.

>
> ...
>
> @@ -540,18 +545,39 @@ ds1307_nvram_read(struct file *filp, str
>  	struct i2c_client	*client;
>  	struct ds1307		*ds1307;
>  	int			result;
> +	unsigned int		addr = 0;
>  
>  	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);
> +	if (ds1307->nvram_offset < 0xff) {	/* ds1307, ds1338 */
> +		result = ds1307->read_block_data(client, ds1307->nvram_offset + off,
> count, buf);
> +	} else	{	/* ds1388 */
> +		if ((off <= 0x00ff) && (off + count > 0x00ff))	{	/* read spans two
> blocks */
> +			client = ds1307->client[1];		/* first block */
> +			addr = (unsigned int)off;
> +			result = ds1307->read_block_data(client, addr, (0x100-addr), buf);

Ignores a possible error return value?

> +			client = ds1307->client[2];		/* second block */
> +			result += ds1307->read_block_data(client, 0x00, (count+addr-0x100),
> (buf+0x100-addr));
> +
> +		} else { 	/* read spans one blocks */
> +			if (off <= 0x00ff)	{
> +				client = ds1307->client[1];
> +				addr = (unsigned int)off;
> +			} else if (off <= 0x0200)	{
> +				client = ds1307->client[2];
> +				addr = (unsigned int)off - 0x100;
> +			}
> +			result = ds1307->read_block_data(client, addr, count, buf);
> +		}
> +	}
>  	if (result < 0)
>  		dev_err(&client->dev, "%s error %d\n", "nvram read", result);
>  	return result;
> @@ -565,18 +591,40 @@ ds1307_nvram_write(struct file *filp, st
>  	struct i2c_client	*client;
>  	struct ds1307		*ds1307;
>  	int			result;
> +	unsigned int		addr = 0;
>  
>  	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);
> +	if (ds1307->nvram_offset < 0xff) {	/* ds1307, ds1338 */
> +		result = ds1307->write_block_data(client, ds1307->nvram_offset + off,
> count, buf);
> +	} else	{	/* ds1388 */
> +		if ((off <= 0x00ff) && ((off + count) > 0x00ff))	{  /* read spans two
> blocks */
> +			client = ds1307->client[1];		/* first block */
> +			addr = (unsigned int)off;
> +			result = ds1307->write_block_data(client, addr, (0x100-addr), buf);

Error checking?

> +			client = ds1307->client[2];		/* second block */
> +			result = ds1307->write_block_data(client, 0x00, (addr+count-0x100),
> (buf+0x100-addr));
> +
> +		} else { /* Device address/offset translation */
> +			dev_dbg(&client->dev, "Write spans one block\n");
> +			if (off <= 0x00ff)	{

A single space before the {

> +				client = ds1307->client[1];
> +				addr = (unsigned int)off;
> +			} else if (off <= 0x0200)	{

ditto

> +				client = ds1307->client[2];
> +				addr = (unsigned int)off - 0x100;
> +			}
> +			result = ds1307->write_block_data(client, addr, count, buf);
> +		}
> +	}
>  	if (result < 0) {
>  		dev_err(&client->dev, "%s error %d\n", "nvram write", result);
>  		return result;
>
> ...
>
> @@ -866,16 +923,35 @@ read_rtc:
>  		dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
>  	}
>  
> -	if (chip->nvram56) {
> +	if (chip->nvram) {
> +		nvram.size = ds1307->nvram_size;
>  		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");
> +			dev_info(&client->dev, "%d bytes nvram\n", nvram.size);
> +		}
> +	}
> +
> +	/* use dummy devices for multiple address chips */
> +	for (i = 1; i < ds1307->num_addrs; i++) {
> +		ds1307->client[i] = i2c_new_dummy(client->adapter, client->addr + i);
> +		if (!ds1307->client[i]) {
> +			dev_err(&client->dev, "address 0x%02x unavailable\n",
> +					client->addr + i);
> +			err = -EADDRINUSE;

EADDRINUSE is a networking error code.  Returning that from an
rtc-related operation might mislead the operator.


> +			goto err_clients;
>  		}
> +		i2c_set_clientdata(ds1307->client[i], ds1307);
>  	}
>  
>  	return 0;
>  
> +err_clients:
> +	for (i = 1; i < ds1307->num_addrs; i++)	{
> +		if (ds1307->client[i])	{
> +			i2c_unregister_device(ds1307->client[i]);
> +		}

We normally omit braces around a single statement.

The `if (ds1307->client[i])' test should be unneeded anyway - just
unregister client[1] though client[i - 1].

Why isn't client[0] used here btw?

> +	}
>  exit_irq:
>  	rtc_device_unregister(ds1307->rtc);
>  exit_free:

Patch

diff -upNr a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
--- a/drivers/rtc/rtc-ds1307.c	2011-06-14 15:56:45.221497487 +1200
+++ b/drivers/rtc/rtc-ds1307.c	2011-06-14 15:57:28.803510835 +1200
@@ -95,15 +95,19 @@  enum ds_type {
 #	define RX8025_BIT_VDET		0x40
 #	define RX8025_BIT_XST		0x20
 
+#define DS1307_MAX_NUM_ADDRS	3
 
 struct ds1307 {
 	u8			offset; /* register's offset */
+	u16			nvram_size;
+	u16			nvram_offset;
+	u8			num_addrs;
 	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_client	*client;
+	struct i2c_client	*client[DS1307_MAX_NUM_ADDRS];
 	struct rtc_device	*rtc;
 	struct work_struct	work;
 	s32 (*read_block_data)(const struct i2c_client *client, u8 command,
@@ -113,23 +117,26 @@  struct ds1307 {
 };
 
 struct chip_desc {
-	unsigned		nvram56:1;
+	unsigned		nvram:1;
 	unsigned		alarm:1;
 };
 
 static const struct chip_desc chips[] = {
 [ds_1307] = {
-	.nvram56	= 1,
+	.nvram		= 1,
 },
 [ds_1337] = {
 	.alarm		= 1,
 },
 [ds_1338] = {
-	.nvram56	= 1,
+	.nvram		= 1,
 },
 [ds_1339] = {
 	.alarm		= 1,
 },
+[ds_1388] = {
+	.nvram		= 1,
+},
 [ds_1340] = {
 },
 [ds_3231] = {
@@ -248,7 +255,7 @@  static void ds1307_work(struct work_stru
 	int			stat, control;
 
 	ds1307 = container_of(work, struct ds1307, work);
-	client = ds1307->client;
+	client = ds1307->client[0];
 	lock = &ds1307->rtc->ops_lock;
 
 	mutex_lock(lock);
@@ -294,7 +301,7 @@  static int ds1307_get_time(struct device
 	int		tmp;
 
 	/* read the RTC date and time registers all at once */
-	tmp = ds1307->read_block_data(ds1307->client,
+	tmp = ds1307->read_block_data(ds1307->client[0],
 		ds1307->offset, 7, ds1307->regs);
 	if (tmp != 7) {
 		dev_err(dev, "%s error %d\n", "read", tmp);
@@ -372,7 +379,7 @@  static int ds1307_set_time(struct device
 		"write", buf[0], buf[1], buf[2], buf[3],
 		buf[4], buf[5], buf[6]);
 
-	result = ds1307->write_block_data(ds1307->client,
+	result = ds1307->write_block_data(ds1307->client[0],
 		ds1307->offset, 7, buf);
 	if (result < 0) {
 		dev_err(dev, "%s error %d\n", "write", result);
@@ -530,8 +537,6 @@  static const struct rtc_class_ops ds13xx
 
 /*----------------------------------------------------------------------*/
 
-#define NVRAM_SIZE	56
-
 static ssize_t
 ds1307_nvram_read(struct file *filp, struct kobject *kobj,
 		struct bin_attribute *attr,
@@ -540,18 +545,39 @@  ds1307_nvram_read(struct file *filp, str
 	struct i2c_client	*client;
 	struct ds1307		*ds1307;
 	int			result;
+	unsigned int		addr = 0;
 
 	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);
+	if (ds1307->nvram_offset < 0xff) {	/* ds1307, ds1338 */
+		result = ds1307->read_block_data(client, ds1307->nvram_offset + off,
count, buf);
+	} else	{	/* ds1388 */
+		if ((off <= 0x00ff) && (off + count > 0x00ff))	{	/* read spans two
blocks */
+			client = ds1307->client[1];		/* first block */
+			addr = (unsigned int)off;
+			result = ds1307->read_block_data(client, addr, (0x100-addr), buf);
+			client = ds1307->client[2];		/* second block */
+			result += ds1307->read_block_data(client, 0x00, (count+addr-0x100),
(buf+0x100-addr));
+
+		} else { 	/* read spans one blocks */
+			if (off <= 0x00ff)	{
+				client = ds1307->client[1];
+				addr = (unsigned int)off;
+			} else if (off <= 0x0200)	{
+				client = ds1307->client[2];
+				addr = (unsigned int)off - 0x100;
+			}
+			result = ds1307->read_block_data(client, addr, count, buf);
+		}
+	}