[RFC] Modifying i2c-core to support alias driver names compatible with device trees

[RFC] Modifying i2c-core to support alias driver names compatible with device trees

[Jon Smirl]

It was requested to split this code out into a separate thread....

This code modifies the i2c-core to support lists of alias names in the
chip drivers.
For example: .aliases	= (char const
*[]){"ricoh,rs5c372a","ricoh,rs5c372b","ricoh,rv5c386","ricoh,rv5c387a",
0},

Support like this is needed to get the table out of the PowerPC code
that is converting from device tree name into Linux kernel versions.

Once you add the concept of aliases you don't need the separate fields
for base driver name and chip specific type. This patch eliminates the
extra field.

Of course these changes to fsl_soc.c are removed in the other patch
that updates i2c-mpc.c.


Extend i2c-core to support lists of device tree compatible names when
matching drivers

From: Jon Smirl <jonsmirl@gmail.com>


---

 arch/powerpc/sysdev/fsl_soc.c |   33 +++++++++------------------------
 drivers/i2c/i2c-core.c        |   35 ++++++++++++++++++-----------------
 drivers/rtc/rtc-pcf8563.c     |    1 +
 drivers/rtc/rtc-rs5c372.c     |    3 ++-
 include/linux/i2c.h           |   13 +++++++++----
 5 files changed, 39 insertions(+), 46 deletions(-)


diff --git a/arch/powerpc/sysdev/fsl_soc.c b/arch/powerpc/sysdev/fsl_soc.c
index 1cf29c9..e2aafd6 100644
--- a/arch/powerpc/sysdev/fsl_soc.c
+++ b/arch/powerpc/sysdev/fsl_soc.c
@@ -314,27 +314,6 @@ struct i2c_driver_device {
 	char	*i2c_type;
 };

-static struct i2c_driver_device i2c_devices[] __initdata = {
-	{"ricoh,rs5c372a", "rtc-rs5c372", "rs5c372a",},
-	{"ricoh,rs5c372b", "rtc-rs5c372", "rs5c372b",},
-	{"ricoh,rv5c386",  "rtc-rs5c372", "rv5c386",},
-	{"ricoh,rv5c387a", "rtc-rs5c372", "rv5c387a",},
-};
-
-static int __init of_find_i2c_driver(struct device_node *node, struct
i2c_board_info *info)
-{
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(i2c_devices); i++) {
-		if (!of_device_is_compatible(node, i2c_devices[i].of_device))
-			continue;
-		strncpy(info->driver_name, i2c_devices[i].i2c_driver, KOBJ_NAME_LEN);
-		strncpy(info->type, i2c_devices[i].i2c_type, I2C_NAME_SIZE);
-		return 0;
-	}
-	return -ENODEV;
-}
-
 static void __init of_register_i2c_devices(struct device_node
*adap_node, int bus_num)
 {
 	struct device_node *node = NULL;
@@ -342,11 +321,12 @@ static void __init
of_register_i2c_devices(struct device_node *adap_node, int bu
 	while ((node = of_get_next_child(adap_node, node))) {
 		struct i2c_board_info info;
 		const u32 *addr;
+		const char *compatible;
 		int len;

 		addr = of_get_property(node, "reg", &len);
 		if (!addr || len < sizeof(int) || *addr > (1 << 10) - 1) {
-			printk(KERN_WARNING "fsl_ioc.c: invalid i2c device entry\n");
+			printk(KERN_WARNING "i2c-mpc.c: invalid entry, missing reg attribute\n");
 			continue;
 		}

@@ -354,16 +334,21 @@ static void __init
of_register_i2c_devices(struct device_node *adap_node, int bu
 		if (info.irq == NO_IRQ)
 			info.irq = -1;

-		if (of_find_i2c_driver(node, &info) < 0)
+		compatible = of_get_property(node, "compatible", &len);
+		if (!compatible) {
+			printk(KERN_WARNING "i2c-mpc.c: invalid entry, missing compatible
attribute\n");
 			continue;
+		}
+		strncpy(info.name, compatible, sizeof(info.name));

 		info.platform_data = NULL;
 		info.addr = *addr;
-
+		
 		i2c_register_board_info(bus_num, &info, 1);
 	}
 }

+
 static int __init fsl_i2c_of_init(void)
 {
 	struct device_node *np;
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index d663e69..d9a70c2 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -51,6 +51,7 @@ static int i2c_device_match(struct device *dev,
struct device_driver *drv)
 {
 	struct i2c_client	*client = to_i2c_client(dev);
 	struct i2c_driver	*driver = to_i2c_driver(drv);
+	char const **alias;

 	/* make legacy i2c drivers bypass driver model probing entirely;
 	 * such drivers scan each i2c adapter/bus themselves.
@@ -60,8 +61,18 @@ static int i2c_device_match(struct device *dev,
struct device_driver *drv)

 	/* new style drivers use the same kind of driver matching policy
 	 * as platform devices or SPI:  compare device and driver IDs.
+	 * Match against arrary of alias device tree names. When a match
+	 * is found change the reference to point at the copy inside the
+	 * chip driver allowing the caller's string to be freed.
 	 */
-	return strcmp(client->driver_name, drv->name) == 0;
+	alias = driver->aliases;
+	while (*alias) {
+		if (strcmp(client->name, *alias) == 0) {
+			return true;
+		}
+		alias++;
+	}
+	return 0;
 }

 #ifdef	CONFIG_HOTPLUG
@@ -74,11 +85,11 @@ static int i2c_device_uevent(struct device *dev,
char **envp, int num_envp,
 	int			i = 0, length = 0;

 	/* by definition, legacy drivers can't hotplug */
-	if (dev->driver || !client->driver_name)
+	if (dev->driver || !client->name)
 		return 0;

 	if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
-			"MODALIAS=%s", client->driver_name))
+			"MODALIAS=%s", client->name))
 		return -ENOMEM;
 	envp[i] = NULL;
 	dev_dbg(dev, "uevent\n");
@@ -169,22 +180,15 @@ static void i2c_client_dev_release(struct device *dev)
 	kfree(to_i2c_client(dev));
 }

-static ssize_t show_client_name(struct device *dev, struct
device_attribute *attr, char *buf)
-{
-	struct i2c_client *client = to_i2c_client(dev);
-	return sprintf(buf, "%s\n", client->name);
-}
-
 static ssize_t show_modalias(struct device *dev, struct
device_attribute *attr, char *buf)
 {
 	struct i2c_client *client = to_i2c_client(dev);
-	return client->driver_name
-		? sprintf(buf, "%s\n", client->driver_name)
+	return client->name
+		? sprintf(buf, "%s\n", client->name)
 		: 0;
 }

 static struct device_attribute i2c_dev_attrs[] = {
-	__ATTR(name, S_IRUGO, show_client_name, NULL),
 	/* modalias helps coldplug:  modprobe $(cat .../modalias) */
 	__ATTR(modalias, S_IRUGO, show_modalias, NULL),
 	{ },
@@ -233,10 +237,7 @@ i2c_new_device(struct i2c_adapter *adap, struct
i2c_board_info const *info)
 	client->flags = info->flags;
 	client->addr = info->addr;
 	client->irq = info->irq;
-
-	strlcpy(client->driver_name, info->driver_name,
-		sizeof(client->driver_name));
-	strlcpy(client->name, info->type, sizeof(client->name));
+	strlcpy(client->name, info->name, sizeof(info->name));

 	/* a new style driver may be bound to this device when we
 	 * return from this function, or any later moment (e.g. maybe
diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c
index 0242d80..43fedba 100644
--- a/drivers/rtc/rtc-pcf8563.c
+++ b/drivers/rtc/rtc-pcf8563.c
@@ -266,6 +266,7 @@ static struct i2c_driver pcf8563_driver = {
 	.driver		= {
 		.name	= "pcf8563",
 	},
+	.aliases = (char const *[]){"philips,pcf8563", "epson,rtc8564", 0},
 	.id		= I2C_DRIVERID_PCF8563,
 	.attach_adapter = &pcf8563_attach,
 	.detach_client	= &pcf8563_detach,
diff --git a/drivers/rtc/rtc-rs5c372.c b/drivers/rtc/rtc-rs5c372.c
index 6b67b50..b2da981 100644
--- a/drivers/rtc/rtc-rs5c372.c
+++ b/drivers/rtc/rtc-rs5c372.c
@@ -62,11 +62,11 @@


 enum rtc_type {
-	rtc_undef = 0,
 	rtc_rs5c372a,
 	rtc_rs5c372b,
 	rtc_rv5c386,
 	rtc_rv5c387a,
+	rtc_undef,
 };

 /* REVISIT:  this assumes that:
@@ -649,6 +649,7 @@ static struct i2c_driver rs5c372_driver = {
 	.driver		= {
 		.name	= "rtc-rs5c372",
 	},
+	.aliases	= (char const
*[]){"ricoh,rs5c372a","ricoh,rs5c372b","ricoh,rv5c386","ricoh,rv5c387a",	0},
 	.probe		= rs5c372_probe,
 	.remove		= rs5c372_remove,
 };
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 2a32f2f..4384cc1 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -107,6 +107,13 @@ extern s32 i2c_smbus_write_i2c_block_data(struct
i2c_client * client,
 struct i2c_driver {
 	int id;
 	unsigned int class;
+	
+	/* Alias names for the driver. Used to support device trees on
+	 * the PowerPC architecture. Device tree names take the form of
+	 * vendor,chip. For example "epson,rtc8564". Alias is a list of
+	 * strings terminated by a zero entry.
+	 */
+	char const **aliases;

 	/* Notifies the driver that a new bus has appeared. This routine
 	 * can be used by the driver to test if the bus meets its conditions
@@ -146,7 +153,7 @@ struct i2c_driver {
 };
 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)

-#define I2C_NAME_SIZE	20
+#define I2C_NAME_SIZE	40

 /**
  * struct i2c_client - represent an I2C slave device
@@ -181,7 +188,6 @@ struct i2c_client {
 					/* to the client		*/
 	struct device dev;		/* the device structure		*/
 	int irq;			/* irq issued by device (or -1) */
-	char driver_name[KOBJ_NAME_LEN];
 	struct list_head list;
 	struct completion released;
 };
@@ -225,8 +231,7 @@ static inline void i2c_set_clientdata (struct
i2c_client *dev, void *data)
  * with the adapter already known.
  */
 struct i2c_board_info {
-	char		driver_name[KOBJ_NAME_LEN];
-	char		type[I2C_NAME_SIZE];
+	char 		name[I2C_NAME_SIZE];
 	unsigned short	flags;
 	unsigned short	addr;
 	void		*platform_data;


-- 
Jon Smirl
jonsmirl@gmail.com

Re: [RFC] Modifying i2c-core to support alias driver names compatible with device trees

[Jon Smirl]

On 11/6/07, Jon Smirl <jonsmirl@gmail.com> wrote:
> This code modifies the i2c-core to support lists of alias names in the
> chip drivers.

Any comments on this code?

-- 
Jon Smirl
jonsmirl@gmail.com

Re: [RFC] Modifying i2c-core to support alias driver names compatible with device trees

[Stephen Rothwell]

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On Tue, 6 Nov 2007 15:39:42 -0500 "Jon Smirl" <jonsmirl@gmail.com> wrote:
>
> It was requested to split this code out into a separate thread....
> 
> This code modifies the i2c-core to support lists of alias names in the
> chip drivers.
> For example: .aliases	= (char const
> *[]){"ricoh,rs5c372a","ricoh,rs5c372b","ricoh,rv5c386","ricoh,rv5c387a",
> 0},

You should not need the (char const *[]) casts at all.

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au
http://www.canb.auug.org.au/~sfr/

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Re: [RFC] Modifying i2c-core to support alias driver names compatible with device trees

[Jon Smirl]

On 11/7/07, Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> On Tue, 6 Nov 2007 15:39:42 -0500 "Jon Smirl" <jonsmirl@gmail.com> wrote:
> >
> > It was requested to split this code out into a separate thread....
> >
> > This code modifies the i2c-core to support lists of alias names in the
> > chip drivers.
> > For example: .aliases = (char const
> > *[]){"ricoh,rs5c372a","ricoh,rs5c372b","ricoh,rv5c386","ricoh,rv5c387a",
> > 0},
>
> You should not need the (char const *[]) casts at all.

That is what I thought but the compiler complains without it. I tried
everything I could think of to get rid of it.

-- 
Jon Smirl
jonsmirl@gmail.com

Re: [RFC] Modifying i2c-core to support alias driver names compatible with device trees

[Jon Smirl]

After contemplating the vast amounts of feedback I received on the
first version of this patch I reworked it to reduce it's impact. This
version can go in without changing any existing drivers in the kernel.

Currently i2c uses a driver_name/type pair to handle drivers which
support more than one device. This version leaves driver_name/type
alone and create a parallel, alternative naming scheme - aliases. When
the grand merge to remove legacy style i2c drivers happens, the
driver_name/type scheme can be removed and converted to use the alias
strings.

If we can get agreement on this patch, I'll post a new version of the
i2c-mpc.c rewrite patch.

Extend i2c-core to support lists of device tree compatible names when
matching drivers

From: Jon Smirl <jonsmirl@gmail.com>


---

 arch/powerpc/sysdev/fsl_soc.c |   46 ++++++-----------------------------------
 drivers/i2c/i2c-core.c        |   16 +++++++++++++-
 drivers/rtc/rtc-ds1307.c      |   14 ++++++++++++
 drivers/rtc/rtc-ds1374.c      |    1 +
 drivers/rtc/rtc-pcf8563.c     |    1 +
 drivers/rtc/rtc-rs5c372.c     |   18 +++++++++++++---
 include/linux/i2c.h           |   13 +++++++++---
 7 files changed, 63 insertions(+), 46 deletions(-)


diff --git a/arch/powerpc/sysdev/fsl_soc.c b/arch/powerpc/sysdev/fsl_soc.c
index 3ace747..cb95a72 100644
--- a/arch/powerpc/sysdev/fsl_soc.c
+++ b/arch/powerpc/sysdev/fsl_soc.c
@@ -320,48 +320,12 @@ arch_initcall(gfar_of_init);

 #ifdef CONFIG_I2C_BOARDINFO
 #include <linux/i2c.h>
-struct i2c_driver_device {
-	char	*of_device;
-	char	*i2c_driver;
-	char	*i2c_type;
-};
-
-static struct i2c_driver_device i2c_devices[] __initdata = {
-	{"ricoh,rs5c372a", "rtc-rs5c372", "rs5c372a",},
-	{"ricoh,rs5c372b", "rtc-rs5c372", "rs5c372b",},
-	{"ricoh,rv5c386",  "rtc-rs5c372", "rv5c386",},
-	{"ricoh,rv5c387a", "rtc-rs5c372", "rv5c387a",},
-	{"dallas,ds1307",  "rtc-ds1307",  "ds1307",},
-	{"dallas,ds1337",  "rtc-ds1307",  "ds1337",},
-	{"dallas,ds1338",  "rtc-ds1307",  "ds1338",},
-	{"dallas,ds1339",  "rtc-ds1307",  "ds1339",},
-	{"dallas,ds1340",  "rtc-ds1307",  "ds1340",},
-	{"stm,m41t00",     "rtc-ds1307",  "m41t00"},
-	{"dallas,ds1374",  "rtc-ds1374",  "rtc-ds1374",},
-};
-
-static int __init of_find_i2c_driver(struct device_node *node,
-				     struct i2c_board_info *info)
-{
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(i2c_devices); i++) {
-		if (!of_device_is_compatible(node, i2c_devices[i].of_device))
-			continue;
-		if (strlcpy(info->driver_name, i2c_devices[i].i2c_driver,
-			    KOBJ_NAME_LEN) >= KOBJ_NAME_LEN ||
-		    strlcpy(info->type, i2c_devices[i].i2c_type,
-			    I2C_NAME_SIZE) >= I2C_NAME_SIZE)
-			return -ENOMEM;
-		return 0;
-	}
-	return -ENODEV;
-}

 static void __init of_register_i2c_devices(struct device_node *adap_node,
 					   int bus_num)
 {
 	struct device_node *node = NULL;
+	const char *compatible;

 	while ((node = of_get_next_child(adap_node, node))) {
 		struct i2c_board_info info = {};
@@ -378,9 +342,13 @@ static void __init of_register_i2c_devices(struct
device_node *adap_node,
 		if (info.irq == NO_IRQ)
 			info.irq = -1;

-		if (of_find_i2c_driver(node, &info) < 0)
+		compatible = of_get_property(node, "compatible", &len);
+		if (!compatible) {
+			printk(KERN_WARNING "i2c-mpc.c: invalid entry, missing compatible
attribute\n");
 			continue;
-
+		}
+		strncpy(info.name, compatible, sizeof(info.name));
+		
 		info.addr = *addr;

 		i2c_register_board_info(bus_num, &info, 1);
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 1a4e8dc..8b49860 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -51,6 +51,7 @@ static int i2c_device_match(struct device *dev,
struct device_driver *drv)
 {
 	struct i2c_client	*client = to_i2c_client(dev);
 	struct i2c_driver	*driver = to_i2c_driver(drv);
+	char const **alias;

 	/* make legacy i2c drivers bypass driver model probing entirely;
 	 * such drivers scan each i2c adapter/bus themselves.
@@ -61,7 +62,20 @@ static int i2c_device_match(struct device *dev,
struct device_driver *drv)
 	/* new style drivers use the same kind of driver matching policy
 	 * as platform devices or SPI:  compare device and driver IDs.
 	 */
-	return strcmp(client->driver_name, drv->name) == 0;
+	if (strcmp(client->driver_name, drv->name) == 0)
+		return true;
+	
+	/* Match against arrary of alias device tree names. When a match
+	 * is found change the reference to point at the copy inside the
+	 * chip driver allowing the caller's string to be freed.
+ 	 */
+	alias = driver->aliases;
+	while (alias && *alias) {
+		if (strnicmp(client->driver_name, *alias, sizeof client->driver_name) == 0)
+			return true;
+		alias++;
+	}
+	return 0;	
 }

 #ifdef	CONFIG_HOTPLUG
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index db6f3f0..456b7ca 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -135,6 +135,11 @@ static inline const struct chip_desc
*find_chip(const char *s)
 	for (i = 0; i < ARRAY_SIZE(chips); i++)
 		if (strnicmp(s, chips[i].name, sizeof chips[i].name) == 0)
 			return &chips[i];
+	/* check the alias names */
+	for (i = ds_1307; i <= m41t00; i++)
+		if (strnicmp(client->driver_name, ds1307_driver.aliases[i], sizeof
client->driver_name) == 0)
+			return &chips[i];
+	
 	return NULL;
 }

@@ -442,6 +447,15 @@ static struct i2c_driver ds1307_driver = {
 		.name	= "rtc-ds1307",
 		.owner	= THIS_MODULE,
 	},
+	.aliases = (char const *[]){
+		[ds_1307] = "dallas,ds1307",
+		[ds_1337] = "dallas,ds1337",
+		[ds_1338] = "dallas,ds1338",
+		[ds_1339] = "dallas,ds1339",
+		[ds_1340] = "dallas,ds1340",
+		[m41t00] = "stm,m41t00",
+		0
+	},
 	.probe		= ds1307_probe,
 	.remove		= __devexit_p(ds1307_remove),
 };
diff --git a/drivers/rtc/rtc-ds1374.c b/drivers/rtc/rtc-ds1374.c
index 45bda18..df8eca4 100644
--- a/drivers/rtc/rtc-ds1374.c
+++ b/drivers/rtc/rtc-ds1374.c
@@ -427,6 +427,7 @@ static struct i2c_driver ds1374_driver = {
 		.name = "rtc-ds1374",
 		.owner = THIS_MODULE,
 	},
+	.aliases = (char const *[]){"dallas,ds1374", 0},
 	.probe = ds1374_probe,
 	.remove = __devexit_p(ds1374_remove),
 };
diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c
index 0242d80..fa04dc5 100644
--- a/drivers/rtc/rtc-pcf8563.c
+++ b/drivers/rtc/rtc-pcf8563.c
@@ -266,6 +266,7 @@ static struct i2c_driver pcf8563_driver = {
 	.driver		= {
 		.name	= "pcf8563",
 	},
+	.aliases = (char const *[]){"philips,pcf8563", "epson,rtc8564", 0},
 	.id		= I2C_DRIVERID_PCF8563,
 	.attach_adapter = &pcf8563_attach,
 	.detach_client	= &pcf8563_detach,
diff --git a/drivers/rtc/rtc-rs5c372.c b/drivers/rtc/rtc-rs5c372.c
index 6b67b50..b458f5f 100644
--- a/drivers/rtc/rtc-rs5c372.c
+++ b/drivers/rtc/rtc-rs5c372.c
@@ -62,7 +62,6 @@


 enum rtc_type {
-	rtc_undef = 0,
 	rtc_rs5c372a,
 	rtc_rs5c372b,
 	rtc_rv5c386,
@@ -531,8 +530,14 @@ static int rs5c372_probe(struct i2c_client *client)
 	else if (strcmp(client->name, "rv5c387a") == 0)
 		rs5c372->type = rtc_rv5c387a;
 	else {
-		rs5c372->type = rtc_rs5c372b;
-		dev_warn(&client->dev, "assuming rs5c372b\n");
+		/* check the alias names */
+		for (rs5c372->type = rtc_rs5c372a; rs5c372->type <= rtc_rv5c387a;
rs5c372->type++)
+			if (strnicmp(client->driver_name,
rs5c372_driver.aliases[rs5c372->type], sizeof client->driver_name) ==
0)
+				break;
+		if (rs5c372->type > rtc_rv5c387a) {
+			rs5c372->type = rtc_rs5c372b;
+			dev_warn(&client->dev, "assuming rs5c372b\n");
+		}
 	}

 	/* clock may be set for am/pm or 24 hr time */
@@ -649,6 +654,13 @@ static struct i2c_driver rs5c372_driver = {
 	.driver		= {
 		.name	= "rtc-rs5c372",
 	},
+	.aliases	= (char const *[]){
+		[rtc_rs5c372a] = "ricoh,rs5c372a",
+		[rtc_rs5c372b] = "ricoh,rs5c372b",
+		[rtc_rv5c386] = "ricoh,rv5c386",
+		[rtc_rv5c387a] = "ricoh,rv5c387a",
+		0
+	},
 	.probe		= rs5c372_probe,
 	.remove		= rs5c372_remove,
 };
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 8033e6b..b952c8a 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -105,6 +105,13 @@ extern s32 i2c_smbus_write_i2c_block_data(struct
i2c_client * client,
 struct i2c_driver {
 	int id;
 	unsigned int class;
+	
+	/* Alias names for the driver. Used to support device trees on
+	 * the PowerPC architecture. Device tree names take the form of
+	 * vendor,chip. For example "epson,rtc8564". Alias is a list of
+	 * strings terminated by a zero entry.
+	 */
+	char const **aliases;	

 	/* Notifies the driver that a new bus has appeared. This routine
 	 * can be used by the driver to test if the bus meets its conditions
@@ -144,7 +151,7 @@ struct i2c_driver {
 };
 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)

-#define I2C_NAME_SIZE	20
+#define I2C_NAME_SIZE	40

 /**
  * struct i2c_client - represent an I2C slave device
@@ -179,7 +186,7 @@ struct i2c_client {
 					/* to the client		*/
 	struct device dev;		/* the device structure		*/
 	int irq;			/* irq issued by device (or -1) */
-	char driver_name[KOBJ_NAME_LEN];
+	char driver_name[I2C_NAME_SIZE];
 	struct list_head list;
 	struct completion released;
 };
@@ -223,7 +230,7 @@ static inline void i2c_set_clientdata (struct
i2c_client *dev, void *data)
  * with the adapter already known.
  */
 struct i2c_board_info {
-	char		driver_name[KOBJ_NAME_LEN];
+	char		driver_name[I2C_NAME_SIZE];
 	char		type[I2C_NAME_SIZE];
 	unsigned short	flags;
 	unsigned short	addr;


-- 
Jon Smirl
jonsmirl@gmail.com

Re: [RFC] Modifying i2c-core to support alias driver names compatible with device trees

[Andreas Schwab]

Stephen Rothwell <sfr@canb.auug.org.au> writes:

> On Tue, 6 Nov 2007 15:39:42 -0500 "Jon Smirl" <jonsmirl@gmail.com> wrote:
>>
>> It was requested to split this code out into a separate thread....
>> 
>> This code modifies the i2c-core to support lists of alias names in the
>> chip drivers.
>> For example: .aliases	= (char const
>> *[]){"ricoh,rs5c372a","ricoh,rs5c372b","ricoh,rv5c386","ricoh,rv5c387a",
>> 0},
>
> You should not need the (char const *[]) casts at all.

It's not a cast, it's a compound literal.  What it does is to create an
anonymous object, the address of which is the initializer for the
aliases pointer.  Note that the anonymous object is not const qualified.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."